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* Re: [PATCH v2 02/24] drivers/video/fbdev: use ioremap_wc/wt() instead of __ioremap()
From: Daniel Vetter @ 2018-09-13 13:33 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Bartlomiej Zolnierkiewicz, Benjamin Herrenschmidt,
	Dominik Brodowski, Geoff Levand, Jens Axboe, Kumar Gala, Li Yang,
	Michael Ellerman, Nicholas Piggin, Paul Mackerras, Scott Wood,
	aneesh.kumar, linux-fbdev, linux-kernel, dri-devel, linux-block,
	linuxppc-dev, linux-arm-kernel
In-Reply-To: <2f980cf32a05415662272cf052c2b9e2a94c756f.1536692743.git.christophe.leroy@c-s.fr>

On Wed, Sep 12, 2018 at 03:58:17PM +0000, Christophe Leroy wrote:
> _PAGE_NO_CACHE is a platform specific flag. In addition, this flag
> is misleading because one would think it requests a noncached page
> whereas a noncached page is _PAGE_NO_CACHE | _PAGE_GUARDED
> 
> _PAGE_NO_CACHE alone means write combined noncached page, so lets
> use ioremap_wc() instead.
> 
> _PAGE_WRITETHRU is also platform specific flag. Use ioremap_wt()
> instead.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

I wondered why this all showed up in my gfx inbox, then spotted this patch
here.

I trust you way more on the _PAGE_ flags than me, but this looks
reasonable.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> ---
>  drivers/video/fbdev/chipsfb.c    |  3 +--
>  drivers/video/fbdev/controlfb.c  |  5 +----
>  drivers/video/fbdev/platinumfb.c |  5 +----
>  drivers/video/fbdev/valkyriefb.c | 12 ++++++------
>  4 files changed, 9 insertions(+), 16 deletions(-)
> 
> diff --git a/drivers/video/fbdev/chipsfb.c b/drivers/video/fbdev/chipsfb.c
> index f103665cad43..40182ed85648 100644
> --- a/drivers/video/fbdev/chipsfb.c
> +++ b/drivers/video/fbdev/chipsfb.c
> @@ -27,7 +27,6 @@
>  #include <linux/init.h>
>  #include <linux/pci.h>
>  #include <linux/console.h>
> -#include <asm/io.h>
>  
>  #ifdef CONFIG_PMAC_BACKLIGHT
>  #include <asm/backlight.h>
> @@ -401,7 +400,7 @@ static int chipsfb_pci_init(struct pci_dev *dp, const struct pci_device_id *ent)
>  #endif /* CONFIG_PMAC_BACKLIGHT */
>  
>  #ifdef CONFIG_PPC
> -	p->screen_base = __ioremap(addr, 0x200000, _PAGE_NO_CACHE);
> +	p->screen_base = ioremap_wc(addr, 0x200000);
>  #else
>  	p->screen_base = ioremap(addr, 0x200000);
>  #endif
> diff --git a/drivers/video/fbdev/controlfb.c b/drivers/video/fbdev/controlfb.c
> index 8d14b29aafea..9cb0ef7ac29e 100644
> --- a/drivers/video/fbdev/controlfb.c
> +++ b/drivers/video/fbdev/controlfb.c
> @@ -48,9 +48,7 @@
>  #include <linux/nvram.h>
>  #include <linux/adb.h>
>  #include <linux/cuda.h>
> -#include <asm/io.h>
>  #include <asm/prom.h>
> -#include <asm/pgtable.h>
>  #include <asm/btext.h>
>  
>  #include "macmodes.h"
> @@ -715,8 +713,7 @@ static int __init control_of_init(struct device_node *dp)
>  		goto error_out;
>  	}
>  	/* map at most 8MB for the frame buffer */
> -	p->frame_buffer = __ioremap(p->frame_buffer_phys, 0x800000,
> -				    _PAGE_WRITETHRU);
> +	p->frame_buffer = ioremap_wt(p->frame_buffer_phys, 0x800000);
>  
>  	if (!p->control_regs_phys ||
>  	    !request_mem_region(p->control_regs_phys, p->control_regs_size,
> diff --git a/drivers/video/fbdev/platinumfb.c b/drivers/video/fbdev/platinumfb.c
> index 377d3399a3ad..bf6b7fb83cf4 100644
> --- a/drivers/video/fbdev/platinumfb.c
> +++ b/drivers/video/fbdev/platinumfb.c
> @@ -32,9 +32,7 @@
>  #include <linux/nvram.h>
>  #include <linux/of_device.h>
>  #include <linux/of_platform.h>
> -#include <asm/io.h>
>  #include <asm/prom.h>
> -#include <asm/pgtable.h>
>  
>  #include "macmodes.h"
>  #include "platinumfb.h"
> @@ -577,8 +575,7 @@ static int platinumfb_probe(struct platform_device* odev)
>  
>  	/* frame buffer - map only 4MB */
>  	pinfo->frame_buffer_phys = pinfo->rsrc_fb.start;
> -	pinfo->frame_buffer = __ioremap(pinfo->rsrc_fb.start, 0x400000,
> -					_PAGE_WRITETHRU);
> +	pinfo->frame_buffer = ioremap_wt(pinfo->rsrc_fb.start, 0x400000);
>  	pinfo->base_frame_buffer = pinfo->frame_buffer;
>  
>  	/* registers */
> diff --git a/drivers/video/fbdev/valkyriefb.c b/drivers/video/fbdev/valkyriefb.c
> index 275fb98236d3..d51c3a8009cb 100644
> --- a/drivers/video/fbdev/valkyriefb.c
> +++ b/drivers/video/fbdev/valkyriefb.c
> @@ -54,13 +54,11 @@
>  #include <linux/nvram.h>
>  #include <linux/adb.h>
>  #include <linux/cuda.h>
> -#include <asm/io.h>
>  #ifdef CONFIG_MAC
>  #include <asm/macintosh.h>
>  #else
>  #include <asm/prom.h>
>  #endif
> -#include <asm/pgtable.h>
>  
>  #include "macmodes.h"
>  #include "valkyriefb.h"
> @@ -318,7 +316,7 @@ static void __init valkyrie_choose_mode(struct fb_info_valkyrie *p)
>  int __init valkyriefb_init(void)
>  {
>  	struct fb_info_valkyrie	*p;
> -	unsigned long frame_buffer_phys, cmap_regs_phys, flags;
> +	unsigned long frame_buffer_phys, cmap_regs_phys;
>  	int err;
>  	char *option = NULL;
>  
> @@ -337,7 +335,6 @@ int __init valkyriefb_init(void)
>  	/* Hardcoded addresses... welcome to 68k Macintosh country :-) */
>  	frame_buffer_phys = 0xf9000000;
>  	cmap_regs_phys = 0x50f24000;
> -	flags = IOMAP_NOCACHE_SER; /* IOMAP_WRITETHROUGH?? */
>  #else /* ppc (!CONFIG_MAC) */
>  	{
>  		struct device_node *dp;
> @@ -354,7 +351,6 @@ int __init valkyriefb_init(void)
>  
>  		frame_buffer_phys = r.start;
>  		cmap_regs_phys = r.start + 0x304000;
> -		flags = _PAGE_WRITETHRU;
>  	}
>  #endif /* ppc (!CONFIG_MAC) */
>  
> @@ -369,7 +365,11 @@ int __init valkyriefb_init(void)
>  	}
>  	p->total_vram = 0x100000;
>  	p->frame_buffer_phys = frame_buffer_phys;
> -	p->frame_buffer = __ioremap(frame_buffer_phys, p->total_vram, flags);
> +#ifdef CONFIG_MAC
> +	p->frame_buffer = ioremap_nocache(frame_buffer_phys, p->total_vram);
> +#else
> +	p->frame_buffer = ioremap_wt(frame_buffer_phys, p->total_vram);
> +#endif
>  	p->cmap_regs_phys = cmap_regs_phys;
>  	p->cmap_regs = ioremap(p->cmap_regs_phys, 0x1000);
>  	p->valkyrie_regs_phys = cmap_regs_phys+0x6000;
> -- 
> 2.13.3
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

^ permalink raw reply

* [PATCH 4.14 074/115] powerpc/platforms/85xx: fix t1042rdb_diu.c build errors & warning
From: Greg Kroah-Hartman @ 2018-09-13 13:31 UTC (permalink / raw)
  To: linux-kernel
  Cc: Greg Kroah-Hartman, stable, Randy Dunlap, Benjamin Herrenschmidt,
	Paul Mackerras, Michael Ellerman, Scott Wood, Kumar Gala,
	linuxppc-dev, Sasha Levin
In-Reply-To: <20180913131823.327472833@linuxfoundation.org>

4.14-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Randy Dunlap <rdunlap@infradead.org>

[ Upstream commit f5daf77a55ef0e695cc90c440ed6503073ac5e07 ]

Fix build errors and warnings in t1042rdb_diu.c by adding header files
and MODULE_LICENSE().

../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: warning: data definition has no type or storage class
 early_initcall(t1042rdb_diu_init);
../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: error: type defaults to 'int' in declaration of 'early_initcall' [-Werror=implicit-int]
../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: warning: parameter names (without types) in function declaration

and
WARNING: modpost: missing MODULE_LICENSE() in arch/powerpc/platforms/85xx/t1042rdb_diu.o

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Scott Wood <oss@buserror.net>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/powerpc/platforms/85xx/t1042rdb_diu.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/arch/powerpc/platforms/85xx/t1042rdb_diu.c
+++ b/arch/powerpc/platforms/85xx/t1042rdb_diu.c
@@ -9,8 +9,10 @@
  * option) any later version.
  */
 
+#include <linux/init.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 
@@ -150,3 +152,5 @@ static int __init t1042rdb_diu_init(void
 }
 
 early_initcall(t1042rdb_diu_init);
+
+MODULE_LICENSE("GPL");

^ permalink raw reply

* [PATCH 4.18 124/197] powerpc/platforms/85xx: fix t1042rdb_diu.c build errors & warning
From: Greg Kroah-Hartman @ 2018-09-13 13:31 UTC (permalink / raw)
  To: linux-kernel
  Cc: Greg Kroah-Hartman, stable, Randy Dunlap, Benjamin Herrenschmidt,
	Paul Mackerras, Michael Ellerman, Scott Wood, Kumar Gala,
	linuxppc-dev, Sasha Levin
In-Reply-To: <20180913131841.568116777@linuxfoundation.org>

4.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Randy Dunlap <rdunlap@infradead.org>

[ Upstream commit f5daf77a55ef0e695cc90c440ed6503073ac5e07 ]

Fix build errors and warnings in t1042rdb_diu.c by adding header files
and MODULE_LICENSE().

../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: warning: data definition has no type or storage class
 early_initcall(t1042rdb_diu_init);
../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: error: type defaults to 'int' in declaration of 'early_initcall' [-Werror=implicit-int]
../arch/powerpc/platforms/85xx/t1042rdb_diu.c:152:1: warning: parameter names (without types) in function declaration

and
WARNING: modpost: missing MODULE_LICENSE() in arch/powerpc/platforms/85xx/t1042rdb_diu.o

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Scott Wood <oss@buserror.net>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/powerpc/platforms/85xx/t1042rdb_diu.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/arch/powerpc/platforms/85xx/t1042rdb_diu.c
+++ b/arch/powerpc/platforms/85xx/t1042rdb_diu.c
@@ -9,8 +9,10 @@
  * option) any later version.
  */
 
+#include <linux/init.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 
@@ -150,3 +152,5 @@ static int __init t1042rdb_diu_init(void
 }
 
 early_initcall(t1042rdb_diu_init);
+
+MODULE_LICENSE("GPL");

^ permalink raw reply

* Re: [PATCH v3 6/9] kbuild: consolidate Devicetree dtb build rules
From: Geert Uytterhoeven @ 2018-09-13 15:51 UTC (permalink / raw)
  To: Masahiro Yamada
  Cc: Rob Herring,
	open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
	Linux Kernel Mailing List, Frank Rowand, Michal Marek,
	Vineet Gupta, Russell King, Catalin Marinas, Yoshinori Sato,
	Michal Simek, Ralf Baechle, James Hogan, Benjamin Herrenschmidt,
	Paul Mackerras, Michael Ellerman, Chris Zankel, Max Filippov,
	linux-kbuild, arcml, Linux ARM,
	moderated list:H8/300 ARCHITECTURE, Linux MIPS Mailing List,
	nios2-dev, linuxppc-dev, linux-xtensa, Will Deacon, Paul Burton,
	ley.foon.tan
In-Reply-To: <CAK7LNAQFqhWw+LwDoypGG=OP6tH4qf2tT=LvtchK2GoiNyzDXg@mail.gmail.com>

Hi Yamada-san,

On Wed, Sep 12, 2018 at 3:02 AM Masahiro Yamada
<yamada.masahiro@socionext.com> wrote:
> 2018-09-12 0:40 GMT+09:00 Rob Herring <robh@kernel.org>:
> > On Mon, Sep 10, 2018 at 10:04 AM Rob Herring <robh@kernel.org> wrote:
> >> There is nothing arch specific about building dtb files other than their
> >> location under /arch/*/boot/dts/. Keeping each arch aligned is a pain.
> >> The dependencies and supported targets are all slightly different.
> >> Also, a cross-compiler for each arch is needed, but really the host
> >> compiler preprocessor is perfectly fine for building dtbs. Move the
> >> build rules to a common location and remove the arch specific ones. This
> >> is done in a single step to avoid warnings about overriding rules.
> >>
> >> The build dependencies had been a mixture of 'scripts' and/or 'prepare'.
> >> These pull in several dependencies some of which need a target compiler
> >> (specifically devicetable-offsets.h) and aren't needed to build dtbs.
> >> All that is really needed is dtc, so adjust the dependencies to only be
> >> dtc.
> >>
> >> This change enables support 'dtbs_install' on some arches which were
> >> missing the target.
> >
> > [...]
> >
> >> @@ -1215,6 +1215,33 @@ kselftest-merge:
> >>                 $(srctree)/tools/testing/selftests/*/config
> >>         +$(Q)$(MAKE) -f $(srctree)/Makefile olddefconfig
> >>
> >> +# ---------------------------------------------------------------------------
> >> +# Devicetree files
> >> +
> >> +ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/boot/dts/),)
> >> +dtstree := arch/$(SRCARCH)/boot/dts
> >> +endif
> >> +
> >> +ifdef CONFIG_OF_EARLY_FLATTREE
> >
> > This can be true when dtstree is unset. So this line should be this
> > instead to fix the 0-day reported error:
> >
> > ifneq ($(dtstree),)
> >
> >> +
> >> +%.dtb : scripts_dtc
> >> +       $(Q)$(MAKE) $(build)=$(dtstree) $(dtstree)/$@
> >> +
> >> +PHONY += dtbs dtbs_install
> >> +dtbs: scripts_dtc
> >> +       $(Q)$(MAKE) $(build)=$(dtstree)
> >> +
> >> +dtbs_install: dtbs
> >> +       $(Q)$(MAKE) $(dtbinst)=$(dtstree)
> >> +
> >> +all: dtbs
> >> +
> >> +endif
>
>
> Ah, right.
> Even x86 can enable OF and OF_UNITTEST.
>
>
>
> Another solution might be,
> guard it by 'depends on ARCH_SUPPORTS_OF'.
>
>
>
> This is actually what ACPI does.
>
> menuconfig ACPI
>         bool "ACPI (Advanced Configuration and Power Interface) Support"
>         depends on ARCH_SUPPORTS_ACPI
>          ...

ACPI is a real platform feature, as it depends on firmware.

CONFIG_OF can be enabled, and DT overlays can be loaded, on any platform,
even if it has ACPI ;-)

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

^ permalink raw reply

* Re: [PATCH v2 02/24] drivers/video/fbdev: use ioremap_wc/wt() instead of __ioremap()
From: Bartlomiej Zolnierkiewicz @ 2018-09-13 17:02 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Benjamin Herrenschmidt, Dominik Brodowski, Geoff Levand,
	Jens Axboe, Kumar Gala, Li Yang, Michael Ellerman,
	Nicholas Piggin, Paul Mackerras, Scott Wood, aneesh.kumar,
	linux-arm-kernel, linux-block, linux-fbdev, linux-kernel,
	linuxppc-dev, dri-devel
In-Reply-To: <2f980cf32a05415662272cf052c2b9e2a94c756f.1536692743.git.christophe.leroy@c-s.fr>


On 09/12/2018 05:58 PM, Christophe Leroy wrote:
> _PAGE_NO_CACHE is a platform specific flag. In addition, this flag
> is misleading because one would think it requests a noncached page
> whereas a noncached page is _PAGE_NO_CACHE | _PAGE_GUARDED
> 
> _PAGE_NO_CACHE alone means write combined noncached page, so lets
> use ioremap_wc() instead.
> 
> _PAGE_WRITETHRU is also platform specific flag. Use ioremap_wt()
> instead.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>

After reading patch #1 this one LGTM.

Acked-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

> ---
>  drivers/video/fbdev/chipsfb.c    |  3 +--
>  drivers/video/fbdev/controlfb.c  |  5 +----
>  drivers/video/fbdev/platinumfb.c |  5 +----
>  drivers/video/fbdev/valkyriefb.c | 12 ++++++------
>  4 files changed, 9 insertions(+), 16 deletions(-)

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

^ permalink raw reply

* Re: [PATCH] watchdog: mpc8xxx: provide boot status
From: Guenter Roeck @ 2018-09-13 20:25 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Wim Van Sebroeck, Radu Rendec, linux-kernel, linuxppc-dev,
	linux-watchdog
In-Reply-To: <055ff141d12942ed5750cc9e803e730de0e38c93.1536778520.git.christophe.leroy@c-s.fr>

On Thu, Sep 13, 2018 at 08:07:21AM +0000, Christophe Leroy wrote:
> mpc8xxx watchdog driver supports the following platforms:
> - mpc8xx
> - mpc83xx
> - mpc86xx
> 
> Those three platforms have a 32 bits register which provides the
> reason of the last boot, including whether it was caused by the
> watchdog.
> 
> mpc8xx: Register RSR, bit SWRS (bit 3)
> mpc83xx: Register RSR, bit SWRS (bit 28)
> mpc86xx: Register RSTRSCR, bit WDT_RR (bit 11)
> 
> This patch maps the register as defined in the device tree and updates
> wdt.bootstatus based on the value of the watchdog related bit. Then
> the information can be retrieved via the WDIOC_GETBOOTSTATUS ioctl.
> 
> Hereunder is an exemple of devicetree for mpc8xx,

example

> the Reset Status Register being at offset 0x288:
> 
> 		WDT: watchdog@0 {
> 			compatible = "fsl,mpc823-wdt";
> 			reg = <0x0 0x10 0x288 0x4>;

This isn't documented anywhere, and no one wil know how to use it.
So far that was grandfathered in, but with more complex usage
it really needs to be documented.

> 		};
> 
> On the mpc83xx, RSR is at offset 0x910
> On the mpc86xx, RSTRSCR is at offset 0xe0094
> 
> Suggested-by: Radu Rendec <radu.rendec@gmail.com>
> Tested-by: Christophe Leroy <christophe.leroy@c-s.fr> # On mpc885
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> ---
>  drivers/watchdog/mpc8xxx_wdt.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/watchdog/mpc8xxx_wdt.c b/drivers/watchdog/mpc8xxx_wdt.c
> index aca2d6323f8a..2951a485a6b4 100644
> --- a/drivers/watchdog/mpc8xxx_wdt.c
> +++ b/drivers/watchdog/mpc8xxx_wdt.c
> @@ -49,10 +49,12 @@ struct mpc8xxx_wdt {
>  struct mpc8xxx_wdt_type {
>  	int prescaler;
>  	bool hw_enabled;
> +	u32 rsr_mask;
>  };
>  
>  struct mpc8xxx_wdt_ddata {
>  	struct mpc8xxx_wdt __iomem *base;
> +	u32 __iomem *rsr;
>  	struct watchdog_device wdd;
>  	spinlock_t lock;
>  	u16 swtc;
> @@ -137,6 +139,7 @@ static int mpc8xxx_wdt_probe(struct platform_device *ofdev)
>  	struct mpc8xxx_wdt_ddata *ddata;
>  	u32 freq = fsl_get_sys_freq();
>  	bool enabled;
> +	struct device *dev = &ofdev->dev;

If you introduce this variable, please use it everywhere
in the function.

>  
>  	wdt_type = of_device_get_match_data(&ofdev->dev);
>  	if (!wdt_type)
> @@ -160,6 +163,22 @@ static int mpc8xxx_wdt_probe(struct platform_device *ofdev)
>  		return -ENODEV;
>  	}
>  
> +	res = platform_get_resource(ofdev, IORESOURCE_MEM, 1);
> +	ddata->rsr = devm_ioremap_resource(dev, res);
> +	if (IS_ERR(ddata->rsr)) {
> +		dev_info(dev, "Could not map reset status register");

Please, no such message. It would start to show up everywhere unless
devicetree files are updated, which likely won't happen. Then we get
bogged down by people asking where this message suddenly comes from.

> +	} else {
> +		u32 rsr_v = in_be32(ddata->rsr);
> +		bool status = rsr_v & wdt_type->rsr_mask;
> +
> +		ddata->wdd.bootstatus = status ? WDIOF_CARDRESET : 0;
> +		 /* clear reset status bits related to watchdog time */
> +		out_be32(ddata->rsr, wdt_type->rsr_mask);
> +
> +		dev_info(dev, "Last boot was %s by watchdog (RSR = 0x%8.8x)\n",
> +			 status ? "caused" : "not caused", rsr_v);

The hex value of RSR may be interesting for developers, but not for users.
Please drop.

Also, "caused" is redundant. Add it to the base string and add "not "
when needed.

> +	}
> +
>  	spin_lock_init(&ddata->lock);
>  
>  	ddata->wdd.info = &mpc8xxx_wdt_info,
> @@ -216,6 +235,7 @@ static const struct of_device_id mpc8xxx_wdt_match[] = {
>  		.compatible = "mpc83xx_wdt",
>  		.data = &(struct mpc8xxx_wdt_type) {
>  			.prescaler = 0x10000,
> +			.rsr_mask = BIT(3), /* RSR Bit 28 */

The comment is quite useless. How does BIT(3) match RSR bit 28 ?
I am sure it is because the HW manual counts bits the other way,
but here it is just confusing and thus doesn't add value unless
you provide additional context.

>  		},
>  	},
>  	{
> @@ -223,6 +243,7 @@ static const struct of_device_id mpc8xxx_wdt_match[] = {
>  		.data = &(struct mpc8xxx_wdt_type) {
>  			.prescaler = 0x10000,
>  			.hw_enabled = true,
> +			.rsr_mask = BIT(20), /* RSTRSCR Bit 11 */
>  		},
>  	},
>  	{
> @@ -230,6 +251,7 @@ static const struct of_device_id mpc8xxx_wdt_match[] = {
>  		.data = &(struct mpc8xxx_wdt_type) {
>  			.prescaler = 0x800,
>  			.hw_enabled = true,
> +			.rsr_mask = BIT(28), /* RSR Bit 3 */
>  		},
>  	},
>  	{},
> -- 
> 2.13.3
> 

^ permalink raw reply

* [PATCH 1/3] libfdt: Ensure INT_MAX is defined in libfdt_env.h
From: Rob Herring @ 2018-09-13 20:28 UTC (permalink / raw)
  To: devicetree
  Cc: linux-kernel, linux-arm-kernel, linuxppc-dev, Frank Rowand,
	Russell King, Benjamin Herrenschmidt, Paul Mackerras,
	Michael Ellerman

The next update of libfdt has a new dependency on INT_MAX. Update the
instances of libfdt_env.h in the kernel to either include the necessary
header with the definition or define it locally.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
---
 arch/arm/boot/compressed/libfdt_env.h | 2 ++
 arch/powerpc/boot/libfdt_env.h        | 2 ++
 include/linux/libfdt_env.h            | 1 +
 3 files changed, 5 insertions(+)

diff --git a/arch/arm/boot/compressed/libfdt_env.h b/arch/arm/boot/compressed/libfdt_env.h
index 07437816e098..b36c0289a308 100644
--- a/arch/arm/boot/compressed/libfdt_env.h
+++ b/arch/arm/boot/compressed/libfdt_env.h
@@ -6,6 +6,8 @@
 #include <linux/string.h>
 #include <asm/byteorder.h>
 
+#define INT_MAX			((int)(~0U>>1))
+
 typedef __be16 fdt16_t;
 typedef __be32 fdt32_t;
 typedef __be64 fdt64_t;
diff --git a/arch/powerpc/boot/libfdt_env.h b/arch/powerpc/boot/libfdt_env.h
index 2a0c8b1bf147..2abc8e83b95e 100644
--- a/arch/powerpc/boot/libfdt_env.h
+++ b/arch/powerpc/boot/libfdt_env.h
@@ -5,6 +5,8 @@
 #include <types.h>
 #include <string.h>
 
+#define INT_MAX			((int)(~0U>>1))
+
 #include "of.h"
 
 typedef unsigned long uintptr_t;
diff --git a/include/linux/libfdt_env.h b/include/linux/libfdt_env.h
index c6ac1fe7ec68..edb0f0c30904 100644
--- a/include/linux/libfdt_env.h
+++ b/include/linux/libfdt_env.h
@@ -2,6 +2,7 @@
 #ifndef LIBFDT_ENV_H
 #define LIBFDT_ENV_H
 
+#include <linux/kernel.h>	/* For INT_MAX */
 #include <linux/string.h>
 
 #include <asm/byteorder.h>
-- 
2.17.1

^ permalink raw reply related

* [PATCH 2/3] scripts/dtc: Add yamltree.c to dtc sources
From: Rob Herring @ 2018-09-13 20:28 UTC (permalink / raw)
  To: devicetree; +Cc: linux-kernel, linux-arm-kernel, linuxppc-dev, Frank Rowand
In-Reply-To: <20180913202828.15372-1-robh@kernel.org>

dtc has a new source file, yamltree.c, that needs to be copied when
syncing dtc sources.

Signed-off-by: Rob Herring <robh@kernel.org>
---
 scripts/dtc/update-dtc-source.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/dtc/update-dtc-source.sh b/scripts/dtc/update-dtc-source.sh
index 1a009fd195d0..7dd29a0362b8 100755
--- a/scripts/dtc/update-dtc-source.sh
+++ b/scripts/dtc/update-dtc-source.sh
@@ -32,7 +32,7 @@ DTC_UPSTREAM_PATH=`pwd`/../dtc
 DTC_LINUX_PATH=`pwd`/scripts/dtc
 
 DTC_SOURCE="checks.c data.c dtc.c dtc.h flattree.c fstree.c livetree.c srcpos.c \
-		srcpos.h treesource.c util.c util.h version_gen.h Makefile.dtc \
+		srcpos.h treesource.c util.c util.h version_gen.h yamltree.c Makefile.dtc \
 		dtc-lexer.l dtc-parser.y"
 LIBFDT_SOURCE="Makefile.libfdt fdt.c fdt.h fdt_addresses.c fdt_empty_tree.c \
 		fdt_overlay.c fdt_ro.c fdt_rw.c fdt_strerror.c fdt_sw.c \
-- 
2.17.1

^ permalink raw reply related

* [PATCH 3/3] scripts/dtc: Update to upstream version v1.4.7-14-gc86da84d30e4
From: Rob Herring @ 2018-09-13 20:28 UTC (permalink / raw)
  To: devicetree; +Cc: linux-kernel, linux-arm-kernel, linuxppc-dev, Frank Rowand
In-Reply-To: <20180913202828.15372-1-robh@kernel.org>

Major changes are I2C and SPI bus checks, YAML output format (for
future validation), some new libfdt functions, and more libfdt
validation of dtbs.

The YAML addition adds an optional dependency on libyaml. pkg-config is
used to test for it and pkg-config became a kconfig dependency in 4.18.

This adds the following commits from upstream:

c86da84d30e4 Add support for YAML encoded output
361b5e7d8067 Make type_marker_length helper public
bfbfab047e45 pylibfdt: Add a means to add and delete notes
9005f4108e7c pylibfdt: Allow delprop() to return errors
b94c056b137e Make valgrind optional
fd06c54d4711 tests: Better testing of dtc -I fs mode
c3f50c9a86d9 tests: Allow dtbs_equal_unordered to ignore mem reserves
0ac9fdee37c7 dtc: trivial '-I fs -O dts' test
0fd1c8c783f3 pylibfdt: fdt_get_mem_rsv returns 2 uint64_t values
04853cad18f4 pylibfdt: Don't incorrectly / unnecessarily override uint64_t typemap
9619c8619c37 Kill bogus TYPE_BLOB marker type
ac68ff92ae20 parser: add TYPE_STRING marker to path references
90a190eb04d9 checks: add SPI bus checks
53a1bd546905 checks: add I2C bus checks
88f18909db73 dtc: Bump version to v1.4.7
85bce8b2f06d tests: Correction to vg_prepare_blob()
57f7f9e7bc7c tests: Don't call memcmp() with NULL arguments
c12b2b0c20eb libfdt: fdt_address_cells() and fdt_size_cells()
3fe0eeda0b7f livetree: Set phandle properties type to uint32
853649acceba pylibfdt: Support the sequential-write interface
9b0e4fe26093 tests: Improve fdt_resize() tests
1087504bb3e8 libfdt: Add necessary header padding in fdt_create()
c72fa777e613 libfdt: Copy the struct region in fdt_resize()
32b9c6130762 Preserve datatype markers when emitting dts format
6dcb8ba408ec libfdt: Add helpers for accessing unaligned words
42607f21d43e tests: Fix incorrect check name 'prop_name_chars'
9d78c33bf8a1 tests: fix grep for checks error messages
b770f3d1c13f pylibfdt: Support setting the name of a node
2f0d07e678e0 pylibfdt: Add functions to set and get properties as strings
354d3dc55939 pylibfdt: Update the bytearray size with pack()
3c374d46acce pylibfdt: Allow reading integer values from properties
49d32ce40bb4 pylibfdt: Use an unsigned type for fdt32_t
481246a0c13a pylibfdt: Avoid accessing the internal _fdt member in tests
9aafa33d99ed pylibfdt: Add functions to update properties
5a598671fdbf pylibfdt: Support device-tree creation/expansion
483e170625e1 pylibfdt: Add support for reading the memory reserve map
29bb05aa4200 pylibfdt: Add support for the rest of the header functions
582a7159a5d0 pylibfdt: Add support for fdt_next_node()
f0f8c9169819 pylibfdt: Reorder functions to match libfdt.h
64a69d123935 pylibfdt: Return string instead of bytearray from getprop()
4d09a83420df fdtput: Add documentation
e617cbe1bd67 fdtget: Add documentation
180a93924014 Use <inttypes.h> format specifiers in a bunch of places we should
b9af3b396576 scripts/dtc: Fixed format mismatch in fprintf
4b8fcc3d015c libfdt: Add fdt_check_full() function
c14223fb2292 tests: Use valgrind client requests for better checking
5b67d2b955a3 tests: Better handling of valgrind errors saving blobs
e2556aaeb506 tests: Remove unused #define
fb9c6abddaa8 Use size_t for blob lengths in utilfdt_read*
0112fda03bf6 libfdt: Add fdt_header_size()
6473a21d8bfe Consolidate utilfdt_read_len() variants
d5db5382c5e5 libfdt: Safer access to memory reservations
719d582e98ec libfdt: Propagate name errors in fdt_getprop_by_offset()
70166d62a27f libfdt: Safer access to strings section
eb890c0f77dc libfdt: Make fdt_check_header() more thorough
899d6fad93f3 libfdt: Improve sequential write state checking
04b5b4062ccd libfdt: Clean up header checking functions
44d3efedc816 Preserve datatype information when parsing dts
f0be81bd8de0 Make Property a subclass of bytearray
24b1f3f064d4 pylibfdt: Add a method to access the device tree directly

Signed-off-by: Rob Herring <robh@kernel.org>
---
As usual, this generated from a script copying from upstream dtc. The 
only part here that's not is dtc/Makefile.


 scripts/dtc/Makefile                 |   7 +
 scripts/dtc/Makefile.dtc             |   4 +
 scripts/dtc/checks.c                 | 143 ++++++++++++++++
 scripts/dtc/data.c                   |   4 +-
 scripts/dtc/dtc-parser.y             |  16 +-
 scripts/dtc/dtc.c                    |  11 ++
 scripts/dtc/dtc.h                    |  13 ++
 scripts/dtc/flattree.c               |   2 +-
 scripts/dtc/libfdt/fdt.c             |  81 ++++++++-
 scripts/dtc/libfdt/fdt_addresses.c   |  35 ++--
 scripts/dtc/libfdt/fdt_overlay.c     |   6 +-
 scripts/dtc/libfdt/fdt_ro.c          | 199 ++++++++++++++++++---
 scripts/dtc/libfdt/fdt_rw.c          |  28 +--
 scripts/dtc/libfdt/fdt_sw.c          | 109 +++++++++---
 scripts/dtc/libfdt/libfdt.h          |  76 ++++++++-
 scripts/dtc/libfdt/libfdt_env.h      |   1 +
 scripts/dtc/libfdt/libfdt_internal.h |   5 +-
 scripts/dtc/livetree.c               |  12 +-
 scripts/dtc/treesource.c             | 225 ++++++++++++++----------
 scripts/dtc/util.c                   |  23 +--
 scripts/dtc/util.h                   |  20 +--
 scripts/dtc/version_gen.h            |   2 +-
 scripts/dtc/yamltree.c               | 247 +++++++++++++++++++++++++++
 23 files changed, 1033 insertions(+), 236 deletions(-)
 create mode 100644 scripts/dtc/yamltree.c

diff --git a/scripts/dtc/Makefile b/scripts/dtc/Makefile
index 1c943e03eaf2..1937ac3187ee 100644
--- a/scripts/dtc/Makefile
+++ b/scripts/dtc/Makefile
@@ -11,6 +11,13 @@ dtc-objs	+= dtc-lexer.lex.o dtc-parser.tab.o
 # Source files need to get at the userspace version of libfdt_env.h to compile
 HOST_EXTRACFLAGS := -I$(src)/libfdt
 
+ifeq ($(shell pkg-config --exists yaml-0.1; echo $$?),1)
+HOST_EXTRACFLAGS += -DNO_YAML
+else
+dtc-objs	+= yamltree.o
+HOSTLDLIBS_dtc	:= $(shell pkg-config --libs yaml-0.1)
+endif
+
 # Generated files need one more search path to include headers in source tree
 HOSTCFLAGS_dtc-lexer.lex.o := -I$(src)
 HOSTCFLAGS_dtc-parser.tab.o := -I$(src)
diff --git a/scripts/dtc/Makefile.dtc b/scripts/dtc/Makefile.dtc
index bece49b35535..d4375630a7f7 100644
--- a/scripts/dtc/Makefile.dtc
+++ b/scripts/dtc/Makefile.dtc
@@ -14,5 +14,9 @@ DTC_SRCS = \
 	treesource.c \
 	util.c
 
+ifneq ($(NO_YAML),1)
+DTC_SRCS += yamltree.c
+endif
+
 DTC_GEN_SRCS = dtc-lexer.lex.c dtc-parser.tab.c
 DTC_OBJS = $(DTC_SRCS:%.c=%.o) $(DTC_GEN_SRCS:%.c=%.o)
diff --git a/scripts/dtc/checks.c b/scripts/dtc/checks.c
index a2cc1036c915..9c9b0c328af6 100644
--- a/scripts/dtc/checks.c
+++ b/scripts/dtc/checks.c
@@ -962,6 +962,143 @@ static void check_simple_bus_reg(struct check *c, struct dt_info *dti, struct no
 }
 WARNING(simple_bus_reg, check_simple_bus_reg, NULL, &reg_format, &simple_bus_bridge);
 
+static const struct bus_type i2c_bus = {
+	.name = "i2c-bus",
+};
+
+static void check_i2c_bus_bridge(struct check *c, struct dt_info *dti, struct node *node)
+{
+	if (strprefixeq(node->name, node->basenamelen, "i2c-bus") ||
+	    strprefixeq(node->name, node->basenamelen, "i2c-arb")) {
+		node->bus = &i2c_bus;
+	} else if (strprefixeq(node->name, node->basenamelen, "i2c")) {
+		struct node *child;
+		for_each_child(node, child) {
+			if (strprefixeq(child->name, node->basenamelen, "i2c-bus"))
+				return;
+		}
+		node->bus = &i2c_bus;
+	} else
+		return;
+
+	if (!node->children)
+		return;
+
+	if (node_addr_cells(node) != 1)
+		FAIL(c, dti, node, "incorrect #address-cells for I2C bus");
+	if (node_size_cells(node) != 0)
+		FAIL(c, dti, node, "incorrect #size-cells for I2C bus");
+
+}
+WARNING(i2c_bus_bridge, check_i2c_bus_bridge, NULL, &addr_size_cells);
+
+static void check_i2c_bus_reg(struct check *c, struct dt_info *dti, struct node *node)
+{
+	struct property *prop;
+	const char *unitname = get_unitname(node);
+	char unit_addr[17];
+	uint32_t reg = 0;
+	int len;
+	cell_t *cells = NULL;
+
+	if (!node->parent || (node->parent->bus != &i2c_bus))
+		return;
+
+	prop = get_property(node, "reg");
+	if (prop)
+		cells = (cell_t *)prop->val.val;
+
+	if (!cells) {
+		FAIL(c, dti, node, "missing or empty reg property");
+		return;
+	}
+
+	reg = fdt32_to_cpu(*cells);
+	snprintf(unit_addr, sizeof(unit_addr), "%x", reg);
+	if (!streq(unitname, unit_addr))
+		FAIL(c, dti, node, "I2C bus unit address format error, expected \"%s\"",
+		     unit_addr);
+
+	for (len = prop->val.len; len > 0; len -= 4) {
+		reg = fdt32_to_cpu(*(cells++));
+		if (reg > 0x3ff)
+			FAIL_PROP(c, dti, node, prop, "I2C address must be less than 10-bits, got \"0x%x\"",
+				  reg);
+
+	}
+}
+WARNING(i2c_bus_reg, check_i2c_bus_reg, NULL, &reg_format, &i2c_bus_bridge);
+
+static const struct bus_type spi_bus = {
+	.name = "spi-bus",
+};
+
+static void check_spi_bus_bridge(struct check *c, struct dt_info *dti, struct node *node)
+{
+
+	if (strprefixeq(node->name, node->basenamelen, "spi")) {
+		node->bus = &spi_bus;
+	} else {
+		/* Try to detect SPI buses which don't have proper node name */
+		struct node *child;
+
+		if (node_addr_cells(node) != 1 || node_size_cells(node) != 0)
+			return;
+
+		for_each_child(node, child) {
+			struct property *prop;
+			for_each_property(child, prop) {
+				if (strprefixeq(prop->name, 4, "spi-")) {
+					node->bus = &spi_bus;
+					break;
+				}
+			}
+			if (node->bus == &spi_bus)
+				break;
+		}
+
+		if (node->bus == &spi_bus && get_property(node, "reg"))
+			FAIL(c, dti, node, "node name for SPI buses should be 'spi'");
+	}
+	if (node->bus != &spi_bus || !node->children)
+		return;
+
+	if (node_addr_cells(node) != 1)
+		FAIL(c, dti, node, "incorrect #address-cells for SPI bus");
+	if (node_size_cells(node) != 0)
+		FAIL(c, dti, node, "incorrect #size-cells for SPI bus");
+
+}
+WARNING(spi_bus_bridge, check_spi_bus_bridge, NULL, &addr_size_cells);
+
+static void check_spi_bus_reg(struct check *c, struct dt_info *dti, struct node *node)
+{
+	struct property *prop;
+	const char *unitname = get_unitname(node);
+	char unit_addr[9];
+	uint32_t reg = 0;
+	cell_t *cells = NULL;
+
+	if (!node->parent || (node->parent->bus != &spi_bus))
+		return;
+
+	prop = get_property(node, "reg");
+	if (prop)
+		cells = (cell_t *)prop->val.val;
+
+	if (!cells) {
+		FAIL(c, dti, node, "missing or empty reg property");
+		return;
+	}
+
+	reg = fdt32_to_cpu(*cells);
+	snprintf(unit_addr, sizeof(unit_addr), "%x", reg);
+	if (!streq(unitname, unit_addr))
+		FAIL(c, dti, node, "SPI bus unit address format error, expected \"%s\"",
+		     unit_addr);
+}
+WARNING(spi_bus_reg, check_spi_bus_reg, NULL, &reg_format, &spi_bus_bridge);
+
 static void check_unit_address_format(struct check *c, struct dt_info *dti,
 				      struct node *node)
 {
@@ -1582,6 +1719,12 @@ static struct check *check_table[] = {
 	&simple_bus_bridge,
 	&simple_bus_reg,
 
+	&i2c_bus_bridge,
+	&i2c_bus_reg,
+
+	&spi_bus_bridge,
+	&spi_bus_reg,
+
 	&avoid_default_addr_size,
 	&avoid_unnecessary_addr_size,
 	&unique_unit_address,
diff --git a/scripts/dtc/data.c b/scripts/dtc/data.c
index aa37a16c8891..4a204145cc7b 100644
--- a/scripts/dtc/data.c
+++ b/scripts/dtc/data.c
@@ -74,7 +74,8 @@ struct data data_copy_escape_string(const char *s, int len)
 	struct data d;
 	char *q;
 
-	d = data_grow_for(empty_data, len + 1);
+	d = data_add_marker(empty_data, TYPE_STRING, NULL);
+	d = data_grow_for(d, len + 1);
 
 	q = d.val;
 	while (i < len) {
@@ -94,6 +95,7 @@ struct data data_copy_file(FILE *f, size_t maxlen)
 {
 	struct data d = empty_data;
 
+	d = data_add_marker(d, TYPE_NONE, NULL);
 	while (!feof(f) && (d.len < maxlen)) {
 		size_t chunksize, ret;
 
diff --git a/scripts/dtc/dtc-parser.y b/scripts/dtc/dtc-parser.y
index 011a5b25539a..dd70ebf386f4 100644
--- a/scripts/dtc/dtc-parser.y
+++ b/scripts/dtc/dtc-parser.y
@@ -287,6 +287,7 @@ propdata:
 		}
 	| propdataprefix DT_REF
 		{
+			$1 = data_add_marker($1, TYPE_STRING, $2);
 			$$ = data_add_marker($1, REF_PATH, $2);
 		}
 	| propdataprefix DT_INCBIN '(' DT_STRING ',' integer_prim ',' integer_prim ')'
@@ -340,22 +341,27 @@ arrayprefix:
 	DT_BITS DT_LITERAL '<'
 		{
 			unsigned long long bits;
+			enum markertype type = TYPE_UINT32;
 
 			bits = $2;
 
-			if ((bits !=  8) && (bits != 16) &&
-			    (bits != 32) && (bits != 64)) {
+			switch (bits) {
+			case 8: type = TYPE_UINT8; break;
+			case 16: type = TYPE_UINT16; break;
+			case 32: type = TYPE_UINT32; break;
+			case 64: type = TYPE_UINT64; break;
+			default:
 				ERROR(&@2, "Array elements must be"
 				      " 8, 16, 32 or 64-bits");
 				bits = 32;
 			}
 
-			$$.data = empty_data;
+			$$.data = data_add_marker(empty_data, type, NULL);
 			$$.bits = bits;
 		}
 	| '<'
 		{
-			$$.data = empty_data;
+			$$.data = data_add_marker(empty_data, TYPE_UINT32, NULL);
 			$$.bits = 32;
 		}
 	| arrayprefix integer_prim
@@ -499,7 +505,7 @@ integer_unary:
 bytestring:
 	  /* empty */
 		{
-			$$ = empty_data;
+			$$ = data_add_marker(empty_data, TYPE_UINT8, NULL);
 		}
 	| bytestring DT_BYTE
 		{
diff --git a/scripts/dtc/dtc.c b/scripts/dtc/dtc.c
index c36994e6eac5..64134aadb997 100644
--- a/scripts/dtc/dtc.c
+++ b/scripts/dtc/dtc.c
@@ -95,6 +95,9 @@ static const char * const usage_opts_help[] = {
 	"\n\tOutput formats are:\n"
 	 "\t\tdts - device tree source text\n"
 	 "\t\tdtb - device tree blob\n"
+#ifndef NO_YAML
+	 "\t\tyaml - device tree encoded as YAML\n"
+#endif
 	 "\t\tasm - assembler source",
 	"\n\tBlob version to produce, defaults to "stringify(DEFAULT_FDT_VERSION)" (for dtb and asm output)",
 	"\n\tOutput dependency file",
@@ -128,6 +131,8 @@ static const char *guess_type_by_name(const char *fname, const char *fallback)
 		return fallback;
 	if (!strcasecmp(s, ".dts"))
 		return "dts";
+	if (!strcasecmp(s, ".yaml"))
+		return "yaml";
 	if (!strcasecmp(s, ".dtb"))
 		return "dtb";
 	return fallback;
@@ -350,6 +355,12 @@ int main(int argc, char *argv[])
 
 	if (streq(outform, "dts")) {
 		dt_to_source(outf, dti);
+#ifndef NO_YAML
+	} else if (streq(outform, "yaml")) {
+		if (!streq(inform, "dts"))
+			die("YAML output format requires dts input format\n");
+		dt_to_yaml(outf, dti);
+#endif
 	} else if (streq(outform, "dtb")) {
 		dt_to_blob(outf, dti, outversion);
 	} else if (streq(outform, "asm")) {
diff --git a/scripts/dtc/dtc.h b/scripts/dtc/dtc.h
index 6d667701ab6a..cbe541525c2c 100644
--- a/scripts/dtc/dtc.h
+++ b/scripts/dtc/dtc.h
@@ -74,10 +74,17 @@ typedef uint32_t cell_t;
 
 /* Data blobs */
 enum markertype {
+	TYPE_NONE,
 	REF_PHANDLE,
 	REF_PATH,
 	LABEL,
+	TYPE_UINT8,
+	TYPE_UINT16,
+	TYPE_UINT32,
+	TYPE_UINT64,
+	TYPE_STRING,
 };
+extern const char *markername(enum markertype markertype);
 
 struct  marker {
 	enum markertype type;
@@ -101,6 +108,8 @@ struct data {
 	for_each_marker(m) \
 		if ((m)->type == (t))
 
+size_t type_marker_length(struct marker *m);
+
 void data_free(struct data d);
 
 struct data data_grow_for(struct data d, int xlen);
@@ -290,6 +299,10 @@ struct dt_info *dt_from_blob(const char *fname);
 void dt_to_source(FILE *f, struct dt_info *dti);
 struct dt_info *dt_from_source(const char *f);
 
+/* YAML source */
+
+void dt_to_yaml(FILE *f, struct dt_info *dti);
+
 /* FS trees */
 
 struct dt_info *dt_from_fs(const char *dirname);
diff --git a/scripts/dtc/flattree.c b/scripts/dtc/flattree.c
index 8d268fb785db..851ea87dbc0f 100644
--- a/scripts/dtc/flattree.c
+++ b/scripts/dtc/flattree.c
@@ -393,7 +393,7 @@ void dt_to_blob(FILE *f, struct dt_info *dti, int version)
 			padlen = 0;
 			if (quiet < 1)
 				fprintf(stderr,
-					"Warning: blob size %d >= minimum size %d\n",
+					"Warning: blob size %"PRIu32" >= minimum size %d\n",
 					fdt32_to_cpu(fdt.totalsize), minsize);
 		}
 	}
diff --git a/scripts/dtc/libfdt/fdt.c b/scripts/dtc/libfdt/fdt.c
index 7855a1787763..ae03b1112961 100644
--- a/scripts/dtc/libfdt/fdt.c
+++ b/scripts/dtc/libfdt/fdt.c
@@ -55,7 +55,12 @@
 
 #include "libfdt_internal.h"
 
-int fdt_check_header(const void *fdt)
+/*
+ * Minimal sanity check for a read-only tree. fdt_ro_probe_() checks
+ * that the given buffer contains what appears to be a flattened
+ * device tree with sane information in its header.
+ */
+int fdt_ro_probe_(const void *fdt)
 {
 	if (fdt_magic(fdt) == FDT_MAGIC) {
 		/* Complete tree */
@@ -74,6 +79,78 @@ int fdt_check_header(const void *fdt)
 	return 0;
 }
 
+static int check_off_(uint32_t hdrsize, uint32_t totalsize, uint32_t off)
+{
+	return (off >= hdrsize) && (off <= totalsize);
+}
+
+static int check_block_(uint32_t hdrsize, uint32_t totalsize,
+			uint32_t base, uint32_t size)
+{
+	if (!check_off_(hdrsize, totalsize, base))
+		return 0; /* block start out of bounds */
+	if ((base + size) < base)
+		return 0; /* overflow */
+	if (!check_off_(hdrsize, totalsize, base + size))
+		return 0; /* block end out of bounds */
+	return 1;
+}
+
+size_t fdt_header_size_(uint32_t version)
+{
+	if (version <= 1)
+		return FDT_V1_SIZE;
+	else if (version <= 2)
+		return FDT_V2_SIZE;
+	else if (version <= 3)
+		return FDT_V3_SIZE;
+	else if (version <= 16)
+		return FDT_V16_SIZE;
+	else
+		return FDT_V17_SIZE;
+}
+
+int fdt_check_header(const void *fdt)
+{
+	size_t hdrsize;
+
+	if (fdt_magic(fdt) != FDT_MAGIC)
+		return -FDT_ERR_BADMAGIC;
+	hdrsize = fdt_header_size(fdt);
+	if ((fdt_version(fdt) < FDT_FIRST_SUPPORTED_VERSION)
+	    || (fdt_last_comp_version(fdt) > FDT_LAST_SUPPORTED_VERSION))
+		return -FDT_ERR_BADVERSION;
+	if (fdt_version(fdt) < fdt_last_comp_version(fdt))
+		return -FDT_ERR_BADVERSION;
+
+	if ((fdt_totalsize(fdt) < hdrsize)
+	    || (fdt_totalsize(fdt) > INT_MAX))
+		return -FDT_ERR_TRUNCATED;
+
+	/* Bounds check memrsv block */
+	if (!check_off_(hdrsize, fdt_totalsize(fdt), fdt_off_mem_rsvmap(fdt)))
+		return -FDT_ERR_TRUNCATED;
+
+	/* Bounds check structure block */
+	if (fdt_version(fdt) < 17) {
+		if (!check_off_(hdrsize, fdt_totalsize(fdt),
+				fdt_off_dt_struct(fdt)))
+			return -FDT_ERR_TRUNCATED;
+	} else {
+		if (!check_block_(hdrsize, fdt_totalsize(fdt),
+				  fdt_off_dt_struct(fdt),
+				  fdt_size_dt_struct(fdt)))
+			return -FDT_ERR_TRUNCATED;
+	}
+
+	/* Bounds check strings block */
+	if (!check_block_(hdrsize, fdt_totalsize(fdt),
+			  fdt_off_dt_strings(fdt), fdt_size_dt_strings(fdt)))
+		return -FDT_ERR_TRUNCATED;
+
+	return 0;
+}
+
 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int len)
 {
 	unsigned absoffset = offset + fdt_off_dt_struct(fdt);
@@ -244,7 +321,7 @@ const char *fdt_find_string_(const char *strtab, int tabsize, const char *s)
 
 int fdt_move(const void *fdt, void *buf, int bufsize)
 {
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	if (fdt_totalsize(fdt) > bufsize)
 		return -FDT_ERR_NOSPACE;
diff --git a/scripts/dtc/libfdt/fdt_addresses.c b/scripts/dtc/libfdt/fdt_addresses.c
index eff4dbcc729d..49537b578d03 100644
--- a/scripts/dtc/libfdt/fdt_addresses.c
+++ b/scripts/dtc/libfdt/fdt_addresses.c
@@ -1,6 +1,7 @@
 /*
  * libfdt - Flat Device Tree manipulation
  * Copyright (C) 2014 David Gibson <david@gibson.dropbear.id.au>
+ * Copyright (C) 2018 embedded brains GmbH
  *
  * libfdt is dual licensed: you can use it either under the terms of
  * the GPL, or the BSD license, at your option.
@@ -55,42 +56,32 @@
 
 #include "libfdt_internal.h"
 
-int fdt_address_cells(const void *fdt, int nodeoffset)
+static int fdt_cells(const void *fdt, int nodeoffset, const char *name)
 {
-	const fdt32_t *ac;
+	const fdt32_t *c;
 	int val;
 	int len;
 
-	ac = fdt_getprop(fdt, nodeoffset, "#address-cells", &len);
-	if (!ac)
+	c = fdt_getprop(fdt, nodeoffset, name, &len);
+	if (!c)
 		return 2;
 
-	if (len != sizeof(*ac))
+	if (len != sizeof(*c))
 		return -FDT_ERR_BADNCELLS;
 
-	val = fdt32_to_cpu(*ac);
+	val = fdt32_to_cpu(*c);
 	if ((val <= 0) || (val > FDT_MAX_NCELLS))
 		return -FDT_ERR_BADNCELLS;
 
 	return val;
 }
 
-int fdt_size_cells(const void *fdt, int nodeoffset)
+int fdt_address_cells(const void *fdt, int nodeoffset)
 {
-	const fdt32_t *sc;
-	int val;
-	int len;
-
-	sc = fdt_getprop(fdt, nodeoffset, "#size-cells", &len);
-	if (!sc)
-		return 2;
-
-	if (len != sizeof(*sc))
-		return -FDT_ERR_BADNCELLS;
-
-	val = fdt32_to_cpu(*sc);
-	if ((val < 0) || (val > FDT_MAX_NCELLS))
-		return -FDT_ERR_BADNCELLS;
+	return fdt_cells(fdt, nodeoffset, "#address-cells");
+}
 
-	return val;
+int fdt_size_cells(const void *fdt, int nodeoffset)
+{
+	return fdt_cells(fdt, nodeoffset, "#size-cells");
 }
diff --git a/scripts/dtc/libfdt/fdt_overlay.c b/scripts/dtc/libfdt/fdt_overlay.c
index bf75388ec9a2..5fdab6c6371d 100644
--- a/scripts/dtc/libfdt/fdt_overlay.c
+++ b/scripts/dtc/libfdt/fdt_overlay.c
@@ -697,7 +697,7 @@ static int get_path_len(const void *fdt, int nodeoffset)
 	int len = 0, namelen;
 	const char *name;
 
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	for (;;) {
 		name = fdt_get_name(fdt, nodeoffset, &namelen);
@@ -866,8 +866,8 @@ int fdt_overlay_apply(void *fdt, void *fdto)
 	uint32_t delta = fdt_get_max_phandle(fdt);
 	int ret;
 
-	FDT_CHECK_HEADER(fdt);
-	FDT_CHECK_HEADER(fdto);
+	FDT_RO_PROBE(fdt);
+	FDT_RO_PROBE(fdto);
 
 	ret = overlay_adjust_local_phandles(fdto, delta);
 	if (ret)
diff --git a/scripts/dtc/libfdt/fdt_ro.c b/scripts/dtc/libfdt/fdt_ro.c
index dfb3236da388..eafc14282892 100644
--- a/scripts/dtc/libfdt/fdt_ro.c
+++ b/scripts/dtc/libfdt/fdt_ro.c
@@ -76,17 +76,72 @@ static int fdt_nodename_eq_(const void *fdt, int offset,
 		return 0;
 }
 
+const char *fdt_get_string(const void *fdt, int stroffset, int *lenp)
+{
+	uint32_t absoffset = stroffset + fdt_off_dt_strings(fdt);
+	size_t len;
+	int err;
+	const char *s, *n;
+
+	err = fdt_ro_probe_(fdt);
+	if (err != 0)
+		goto fail;
+
+	err = -FDT_ERR_BADOFFSET;
+	if (absoffset >= fdt_totalsize(fdt))
+		goto fail;
+	len = fdt_totalsize(fdt) - absoffset;
+
+	if (fdt_magic(fdt) == FDT_MAGIC) {
+		if (stroffset < 0)
+			goto fail;
+		if (fdt_version(fdt) >= 17) {
+			if (stroffset >= fdt_size_dt_strings(fdt))
+				goto fail;
+			if ((fdt_size_dt_strings(fdt) - stroffset) < len)
+				len = fdt_size_dt_strings(fdt) - stroffset;
+		}
+	} else if (fdt_magic(fdt) == FDT_SW_MAGIC) {
+		if ((stroffset >= 0)
+		    || (stroffset < -fdt_size_dt_strings(fdt)))
+			goto fail;
+		if ((-stroffset) < len)
+			len = -stroffset;
+	} else {
+		err = -FDT_ERR_INTERNAL;
+		goto fail;
+	}
+
+	s = (const char *)fdt + absoffset;
+	n = memchr(s, '\0', len);
+	if (!n) {
+		/* missing terminating NULL */
+		err = -FDT_ERR_TRUNCATED;
+		goto fail;
+	}
+
+	if (lenp)
+		*lenp = n - s;
+	return s;
+
+fail:
+	if (lenp)
+		*lenp = err;
+	return NULL;
+}
+
 const char *fdt_string(const void *fdt, int stroffset)
 {
-	return (const char *)fdt + fdt_off_dt_strings(fdt) + stroffset;
+	return fdt_get_string(fdt, stroffset, NULL);
 }
 
 static int fdt_string_eq_(const void *fdt, int stroffset,
 			  const char *s, int len)
 {
-	const char *p = fdt_string(fdt, stroffset);
+	int slen;
+	const char *p = fdt_get_string(fdt, stroffset, &slen);
 
-	return (strlen(p) == len) && (memcmp(p, s, len) == 0);
+	return p && (slen == len) && (memcmp(p, s, len) == 0);
 }
 
 uint32_t fdt_get_max_phandle(const void *fdt)
@@ -115,21 +170,42 @@ uint32_t fdt_get_max_phandle(const void *fdt)
 	return 0;
 }
 
+static const struct fdt_reserve_entry *fdt_mem_rsv(const void *fdt, int n)
+{
+	int offset = n * sizeof(struct fdt_reserve_entry);
+	int absoffset = fdt_off_mem_rsvmap(fdt) + offset;
+
+	if (absoffset < fdt_off_mem_rsvmap(fdt))
+		return NULL;
+	if (absoffset > fdt_totalsize(fdt) - sizeof(struct fdt_reserve_entry))
+		return NULL;
+	return fdt_mem_rsv_(fdt, n);
+}
+
 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size)
 {
-	FDT_CHECK_HEADER(fdt);
-	*address = fdt64_to_cpu(fdt_mem_rsv_(fdt, n)->address);
-	*size = fdt64_to_cpu(fdt_mem_rsv_(fdt, n)->size);
+	const struct fdt_reserve_entry *re;
+
+	FDT_RO_PROBE(fdt);
+	re = fdt_mem_rsv(fdt, n);
+	if (!re)
+		return -FDT_ERR_BADOFFSET;
+
+	*address = fdt64_ld(&re->address);
+	*size = fdt64_ld(&re->size);
 	return 0;
 }
 
 int fdt_num_mem_rsv(const void *fdt)
 {
-	int i = 0;
+	int i;
+	const struct fdt_reserve_entry *re;
 
-	while (fdt64_to_cpu(fdt_mem_rsv_(fdt, i)->size) != 0)
-		i++;
-	return i;
+	for (i = 0; (re = fdt_mem_rsv(fdt, i)) != NULL; i++) {
+		if (fdt64_ld(&re->size) == 0)
+			return i;
+	}
+	return -FDT_ERR_TRUNCATED;
 }
 
 static int nextprop_(const void *fdt, int offset)
@@ -161,7 +237,7 @@ int fdt_subnode_offset_namelen(const void *fdt, int offset,
 {
 	int depth;
 
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	for (depth = 0;
 	     (offset >= 0) && (depth >= 0);
@@ -187,7 +263,7 @@ int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen)
 	const char *p = path;
 	int offset = 0;
 
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	/* see if we have an alias */
 	if (*path != '/') {
@@ -237,7 +313,7 @@ const char *fdt_get_name(const void *fdt, int nodeoffset, int *len)
 	const char *nameptr;
 	int err;
 
-	if (((err = fdt_check_header(fdt)) != 0)
+	if (((err = fdt_ro_probe_(fdt)) != 0)
 	    || ((err = fdt_check_node_offset_(fdt, nodeoffset)) < 0))
 			goto fail;
 
@@ -303,7 +379,7 @@ static const struct fdt_property *fdt_get_property_by_offset_(const void *fdt,
 	prop = fdt_offset_ptr_(fdt, offset);
 
 	if (lenp)
-		*lenp = fdt32_to_cpu(prop->len);
+		*lenp = fdt32_ld(&prop->len);
 
 	return prop;
 }
@@ -340,7 +416,7 @@ static const struct fdt_property *fdt_get_property_namelen_(const void *fdt,
 			offset = -FDT_ERR_INTERNAL;
 			break;
 		}
-		if (fdt_string_eq_(fdt, fdt32_to_cpu(prop->nameoff),
+		if (fdt_string_eq_(fdt, fdt32_ld(&prop->nameoff),
 				   name, namelen)) {
 			if (poffset)
 				*poffset = offset;
@@ -393,7 +469,7 @@ const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
 
 	/* Handle realignment */
 	if (fdt_version(fdt) < 0x10 && (poffset + sizeof(*prop)) % 8 &&
-	    fdt32_to_cpu(prop->len) >= 8)
+	    fdt32_ld(&prop->len) >= 8)
 		return prop->data + 4;
 	return prop->data;
 }
@@ -406,12 +482,22 @@ const void *fdt_getprop_by_offset(const void *fdt, int offset,
 	prop = fdt_get_property_by_offset_(fdt, offset, lenp);
 	if (!prop)
 		return NULL;
-	if (namep)
-		*namep = fdt_string(fdt, fdt32_to_cpu(prop->nameoff));
+	if (namep) {
+		const char *name;
+		int namelen;
+		name = fdt_get_string(fdt, fdt32_ld(&prop->nameoff),
+				      &namelen);
+		if (!name) {
+			if (lenp)
+				*lenp = namelen;
+			return NULL;
+		}
+		*namep = name;
+	}
 
 	/* Handle realignment */
 	if (fdt_version(fdt) < 0x10 && (offset + sizeof(*prop)) % 8 &&
-	    fdt32_to_cpu(prop->len) >= 8)
+	    fdt32_ld(&prop->len) >= 8)
 		return prop->data + 4;
 	return prop->data;
 }
@@ -436,7 +522,7 @@ uint32_t fdt_get_phandle(const void *fdt, int nodeoffset)
 			return 0;
 	}
 
-	return fdt32_to_cpu(*php);
+	return fdt32_ld(php);
 }
 
 const char *fdt_get_alias_namelen(const void *fdt,
@@ -462,7 +548,7 @@ int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen)
 	int offset, depth, namelen;
 	const char *name;
 
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	if (buflen < 2)
 		return -FDT_ERR_NOSPACE;
@@ -514,7 +600,7 @@ int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
 	int offset, depth;
 	int supernodeoffset = -FDT_ERR_INTERNAL;
 
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	if (supernodedepth < 0)
 		return -FDT_ERR_NOTFOUND;
@@ -573,7 +659,7 @@ int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
 	const void *val;
 	int len;
 
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	/* FIXME: The algorithm here is pretty horrible: we scan each
 	 * property of a node in fdt_getprop(), then if that didn't
@@ -599,7 +685,7 @@ int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle)
 	if ((phandle == 0) || (phandle == -1))
 		return -FDT_ERR_BADPHANDLE;
 
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	/* FIXME: The algorithm here is pretty horrible: we
 	 * potentially scan each property of a node in
@@ -752,7 +838,7 @@ int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 {
 	int offset, err;
 
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	/* FIXME: The algorithm here is pretty horrible: we scan each
 	 * property of a node in fdt_node_check_compatible(), then if
@@ -771,3 +857,66 @@ int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
 
 	return offset; /* error from fdt_next_node() */
 }
+
+int fdt_check_full(const void *fdt, size_t bufsize)
+{
+	int err;
+	int num_memrsv;
+	int offset, nextoffset = 0;
+	uint32_t tag;
+	unsigned depth = 0;
+	const void *prop;
+	const char *propname;
+
+	if (bufsize < FDT_V1_SIZE)
+		return -FDT_ERR_TRUNCATED;
+	err = fdt_check_header(fdt);
+	if (err != 0)
+		return err;
+	if (bufsize < fdt_totalsize(fdt))
+		return -FDT_ERR_TRUNCATED;
+
+	num_memrsv = fdt_num_mem_rsv(fdt);
+	if (num_memrsv < 0)
+		return num_memrsv;
+
+	while (1) {
+		offset = nextoffset;
+		tag = fdt_next_tag(fdt, offset, &nextoffset);
+
+		if (nextoffset < 0)
+			return nextoffset;
+
+		switch (tag) {
+		case FDT_NOP:
+			break;
+
+		case FDT_END:
+			if (depth != 0)
+				return -FDT_ERR_BADSTRUCTURE;
+			return 0;
+
+		case FDT_BEGIN_NODE:
+			depth++;
+			if (depth > INT_MAX)
+				return -FDT_ERR_BADSTRUCTURE;
+			break;
+
+		case FDT_END_NODE:
+			if (depth == 0)
+				return -FDT_ERR_BADSTRUCTURE;
+			depth--;
+			break;
+
+		case FDT_PROP:
+			prop = fdt_getprop_by_offset(fdt, offset, &propname,
+						     &err);
+			if (!prop)
+				return err;
+			break;
+
+		default:
+			return -FDT_ERR_INTERNAL;
+		}
+	}
+}
diff --git a/scripts/dtc/libfdt/fdt_rw.c b/scripts/dtc/libfdt/fdt_rw.c
index 9b829051e444..2e49855d7cf8 100644
--- a/scripts/dtc/libfdt/fdt_rw.c
+++ b/scripts/dtc/libfdt/fdt_rw.c
@@ -67,9 +67,9 @@ static int fdt_blocks_misordered_(const void *fdt,
 		    (fdt_off_dt_strings(fdt) + fdt_size_dt_strings(fdt)));
 }
 
-static int fdt_rw_check_header_(void *fdt)
+static int fdt_rw_probe_(void *fdt)
 {
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	if (fdt_version(fdt) < 17)
 		return -FDT_ERR_BADVERSION;
@@ -82,10 +82,10 @@ static int fdt_rw_check_header_(void *fdt)
 	return 0;
 }
 
-#define FDT_RW_CHECK_HEADER(fdt) \
+#define FDT_RW_PROBE(fdt) \
 	{ \
 		int err_; \
-		if ((err_ = fdt_rw_check_header_(fdt)) != 0) \
+		if ((err_ = fdt_rw_probe_(fdt)) != 0) \
 			return err_; \
 	}
 
@@ -176,7 +176,7 @@ int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size)
 	struct fdt_reserve_entry *re;
 	int err;
 
-	FDT_RW_CHECK_HEADER(fdt);
+	FDT_RW_PROBE(fdt);
 
 	re = fdt_mem_rsv_w_(fdt, fdt_num_mem_rsv(fdt));
 	err = fdt_splice_mem_rsv_(fdt, re, 0, 1);
@@ -192,7 +192,7 @@ int fdt_del_mem_rsv(void *fdt, int n)
 {
 	struct fdt_reserve_entry *re = fdt_mem_rsv_w_(fdt, n);
 
-	FDT_RW_CHECK_HEADER(fdt);
+	FDT_RW_PROBE(fdt);
 
 	if (n >= fdt_num_mem_rsv(fdt))
 		return -FDT_ERR_NOTFOUND;
@@ -252,7 +252,7 @@ int fdt_set_name(void *fdt, int nodeoffset, const char *name)
 	int oldlen, newlen;
 	int err;
 
-	FDT_RW_CHECK_HEADER(fdt);
+	FDT_RW_PROBE(fdt);
 
 	namep = (char *)(uintptr_t)fdt_get_name(fdt, nodeoffset, &oldlen);
 	if (!namep)
@@ -275,7 +275,7 @@ int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
 	struct fdt_property *prop;
 	int err;
 
-	FDT_RW_CHECK_HEADER(fdt);
+	FDT_RW_PROBE(fdt);
 
 	err = fdt_resize_property_(fdt, nodeoffset, name, len, &prop);
 	if (err == -FDT_ERR_NOTFOUND)
@@ -308,7 +308,7 @@ int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
 	struct fdt_property *prop;
 	int err, oldlen, newlen;
 
-	FDT_RW_CHECK_HEADER(fdt);
+	FDT_RW_PROBE(fdt);
 
 	prop = fdt_get_property_w(fdt, nodeoffset, name, &oldlen);
 	if (prop) {
@@ -334,7 +334,7 @@ int fdt_delprop(void *fdt, int nodeoffset, const char *name)
 	struct fdt_property *prop;
 	int len, proplen;
 
-	FDT_RW_CHECK_HEADER(fdt);
+	FDT_RW_PROBE(fdt);
 
 	prop = fdt_get_property_w(fdt, nodeoffset, name, &len);
 	if (!prop)
@@ -354,7 +354,7 @@ int fdt_add_subnode_namelen(void *fdt, int parentoffset,
 	uint32_t tag;
 	fdt32_t *endtag;
 
-	FDT_RW_CHECK_HEADER(fdt);
+	FDT_RW_PROBE(fdt);
 
 	offset = fdt_subnode_offset_namelen(fdt, parentoffset, name, namelen);
 	if (offset >= 0)
@@ -394,7 +394,7 @@ int fdt_del_node(void *fdt, int nodeoffset)
 {
 	int endoffset;
 
-	FDT_RW_CHECK_HEADER(fdt);
+	FDT_RW_PROBE(fdt);
 
 	endoffset = fdt_node_end_offset_(fdt, nodeoffset);
 	if (endoffset < 0)
@@ -435,7 +435,7 @@ int fdt_open_into(const void *fdt, void *buf, int bufsize)
 	const char *fdtend = fdtstart + fdt_totalsize(fdt);
 	char *tmp;
 
-	FDT_CHECK_HEADER(fdt);
+	FDT_RO_PROBE(fdt);
 
 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
 		* sizeof(struct fdt_reserve_entry);
@@ -494,7 +494,7 @@ int fdt_pack(void *fdt)
 {
 	int mem_rsv_size;
 
-	FDT_RW_CHECK_HEADER(fdt);
+	FDT_RW_PROBE(fdt);
 
 	mem_rsv_size = (fdt_num_mem_rsv(fdt)+1)
 		* sizeof(struct fdt_reserve_entry);
diff --git a/scripts/dtc/libfdt/fdt_sw.c b/scripts/dtc/libfdt/fdt_sw.c
index 6d33cc29d022..9fa4a94d83c3 100644
--- a/scripts/dtc/libfdt/fdt_sw.c
+++ b/scripts/dtc/libfdt/fdt_sw.c
@@ -55,21 +55,77 @@
 
 #include "libfdt_internal.h"
 
-static int fdt_sw_check_header_(void *fdt)
+static int fdt_sw_probe_(void *fdt)
 {
-	if (fdt_magic(fdt) != FDT_SW_MAGIC)
+	if (fdt_magic(fdt) == FDT_MAGIC)
+		return -FDT_ERR_BADSTATE;
+	else if (fdt_magic(fdt) != FDT_SW_MAGIC)
 		return -FDT_ERR_BADMAGIC;
-	/* FIXME: should check more details about the header state */
 	return 0;
 }
 
-#define FDT_SW_CHECK_HEADER(fdt) \
+#define FDT_SW_PROBE(fdt) \
+	{ \
+		int err; \
+		if ((err = fdt_sw_probe_(fdt)) != 0) \
+			return err; \
+	}
+
+/* 'memrsv' state:	Initial state after fdt_create()
+ *
+ * Allowed functions:
+ *	fdt_add_reservmap_entry()
+ *	fdt_finish_reservemap()		[moves to 'struct' state]
+ */
+static int fdt_sw_probe_memrsv_(void *fdt)
+{
+	int err = fdt_sw_probe_(fdt);
+	if (err)
+		return err;
+
+	if (fdt_off_dt_strings(fdt) != 0)
+		return -FDT_ERR_BADSTATE;
+	return 0;
+}
+
+#define FDT_SW_PROBE_MEMRSV(fdt) \
+	{ \
+		int err; \
+		if ((err = fdt_sw_probe_memrsv_(fdt)) != 0) \
+			return err; \
+	}
+
+/* 'struct' state:	Enter this state after fdt_finish_reservemap()
+ *
+ * Allowed functions:
+ *	fdt_begin_node()
+ *	fdt_end_node()
+ *	fdt_property*()
+ *	fdt_finish()			[moves to 'complete' state]
+ */
+static int fdt_sw_probe_struct_(void *fdt)
+{
+	int err = fdt_sw_probe_(fdt);
+	if (err)
+		return err;
+
+	if (fdt_off_dt_strings(fdt) != fdt_totalsize(fdt))
+		return -FDT_ERR_BADSTATE;
+	return 0;
+}
+
+#define FDT_SW_PROBE_STRUCT(fdt) \
 	{ \
 		int err; \
-		if ((err = fdt_sw_check_header_(fdt)) != 0) \
+		if ((err = fdt_sw_probe_struct_(fdt)) != 0) \
 			return err; \
 	}
 
+/* 'complete' state:	Enter this state after fdt_finish()
+ *
+ * Allowed functions: none
+ */
+
 static void *fdt_grab_space_(void *fdt, size_t len)
 {
 	int offset = fdt_size_dt_struct(fdt);
@@ -87,9 +143,11 @@ static void *fdt_grab_space_(void *fdt, size_t len)
 
 int fdt_create(void *buf, int bufsize)
 {
+	const size_t hdrsize = FDT_ALIGN(sizeof(struct fdt_header),
+					 sizeof(struct fdt_reserve_entry));
 	void *fdt = buf;
 
-	if (bufsize < sizeof(struct fdt_header))
+	if (bufsize < hdrsize)
 		return -FDT_ERR_NOSPACE;
 
 	memset(buf, 0, bufsize);
@@ -99,10 +157,9 @@ int fdt_create(void *buf, int bufsize)
 	fdt_set_last_comp_version(fdt, FDT_FIRST_SUPPORTED_VERSION);
 	fdt_set_totalsize(fdt,  bufsize);
 
-	fdt_set_off_mem_rsvmap(fdt, FDT_ALIGN(sizeof(struct fdt_header),
-					      sizeof(struct fdt_reserve_entry)));
+	fdt_set_off_mem_rsvmap(fdt, hdrsize);
 	fdt_set_off_dt_struct(fdt, fdt_off_mem_rsvmap(fdt));
-	fdt_set_off_dt_strings(fdt, bufsize);
+	fdt_set_off_dt_strings(fdt, 0);
 
 	return 0;
 }
@@ -112,11 +169,14 @@ int fdt_resize(void *fdt, void *buf, int bufsize)
 	size_t headsize, tailsize;
 	char *oldtail, *newtail;
 
-	FDT_SW_CHECK_HEADER(fdt);
+	FDT_SW_PROBE(fdt);
 
-	headsize = fdt_off_dt_struct(fdt);
+	headsize = fdt_off_dt_struct(fdt) + fdt_size_dt_struct(fdt);
 	tailsize = fdt_size_dt_strings(fdt);
 
+	if ((headsize + tailsize) > fdt_totalsize(fdt))
+		return -FDT_ERR_INTERNAL;
+
 	if ((headsize + tailsize) > bufsize)
 		return -FDT_ERR_NOSPACE;
 
@@ -133,8 +193,9 @@ int fdt_resize(void *fdt, void *buf, int bufsize)
 		memmove(buf, fdt, headsize);
 	}
 
-	fdt_set_off_dt_strings(buf, bufsize);
 	fdt_set_totalsize(buf, bufsize);
+	if (fdt_off_dt_strings(buf))
+		fdt_set_off_dt_strings(buf, bufsize);
 
 	return 0;
 }
@@ -144,10 +205,7 @@ int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
 	struct fdt_reserve_entry *re;
 	int offset;
 
-	FDT_SW_CHECK_HEADER(fdt);
-
-	if (fdt_size_dt_struct(fdt))
-		return -FDT_ERR_BADSTATE;
+	FDT_SW_PROBE_MEMRSV(fdt);
 
 	offset = fdt_off_dt_struct(fdt);
 	if ((offset + sizeof(*re)) > fdt_totalsize(fdt))
@@ -164,16 +222,23 @@ int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size)
 
 int fdt_finish_reservemap(void *fdt)
 {
-	return fdt_add_reservemap_entry(fdt, 0, 0);
+	int err = fdt_add_reservemap_entry(fdt, 0, 0);
+
+	if (err)
+		return err;
+
+	fdt_set_off_dt_strings(fdt, fdt_totalsize(fdt));
+	return 0;
 }
 
 int fdt_begin_node(void *fdt, const char *name)
 {
 	struct fdt_node_header *nh;
-	int namelen = strlen(name) + 1;
+	int namelen;
 
-	FDT_SW_CHECK_HEADER(fdt);
+	FDT_SW_PROBE_STRUCT(fdt);
 
+	namelen = strlen(name) + 1;
 	nh = fdt_grab_space_(fdt, sizeof(*nh) + FDT_TAGALIGN(namelen));
 	if (! nh)
 		return -FDT_ERR_NOSPACE;
@@ -187,7 +252,7 @@ int fdt_end_node(void *fdt)
 {
 	fdt32_t *en;
 
-	FDT_SW_CHECK_HEADER(fdt);
+	FDT_SW_PROBE_STRUCT(fdt);
 
 	en = fdt_grab_space_(fdt, FDT_TAGSIZE);
 	if (! en)
@@ -225,7 +290,7 @@ int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp)
 	struct fdt_property *prop;
 	int nameoff;
 
-	FDT_SW_CHECK_HEADER(fdt);
+	FDT_SW_PROBE_STRUCT(fdt);
 
 	nameoff = fdt_find_add_string_(fdt, name);
 	if (nameoff == 0)
@@ -262,7 +327,7 @@ int fdt_finish(void *fdt)
 	uint32_t tag;
 	int offset, nextoffset;
 
-	FDT_SW_CHECK_HEADER(fdt);
+	FDT_SW_PROBE_STRUCT(fdt);
 
 	/* Add terminator */
 	end = fdt_grab_space_(fdt, sizeof(*end));
diff --git a/scripts/dtc/libfdt/libfdt.h b/scripts/dtc/libfdt/libfdt.h
index 1e27780e1185..2bd151dd355f 100644
--- a/scripts/dtc/libfdt/libfdt.h
+++ b/scripts/dtc/libfdt/libfdt.h
@@ -90,8 +90,9 @@
 
 /* Error codes: codes for bad device tree blobs */
 #define FDT_ERR_TRUNCATED	8
-	/* FDT_ERR_TRUNCATED: Structure block of the given device tree
-	 * ends without an FDT_END tag. */
+	/* FDT_ERR_TRUNCATED: FDT or a sub-block is improperly
+	 * terminated (overflows, goes outside allowed bounds, or
+	 * isn't properly terminated).  */
 #define FDT_ERR_BADMAGIC	9
 	/* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
 	 * device tree at all - it is missing the flattened device
@@ -153,6 +154,29 @@ static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
 
 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
 
+/*
+ * Alignment helpers:
+ *     These helpers access words from a device tree blob.  They're
+ *     built to work even with unaligned pointers on platforms (ike
+ *     ARM) that don't like unaligned loads and stores
+ */
+
+static inline uint32_t fdt32_ld(const fdt32_t *p)
+{
+	fdt32_t v;
+
+	memcpy(&v, p, sizeof(v));
+	return fdt32_to_cpu(v);
+}
+
+static inline uint64_t fdt64_ld(const fdt64_t *p)
+{
+	fdt64_t v;
+
+	memcpy(&v, p, sizeof(v));
+	return fdt64_to_cpu(v);
+}
+
 /**********************************************************************/
 /* Traversal functions                                                */
 /**********************************************************************/
@@ -213,7 +237,7 @@ int fdt_next_subnode(const void *fdt, int offset);
 /* General functions                                                  */
 /**********************************************************************/
 #define fdt_get_header(fdt, field) \
-	(fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
+	(fdt32_ld(&((const struct fdt_header *)(fdt))->field))
 #define fdt_magic(fdt)			(fdt_get_header(fdt, magic))
 #define fdt_totalsize(fdt)		(fdt_get_header(fdt, totalsize))
 #define fdt_off_dt_struct(fdt)		(fdt_get_header(fdt, off_dt_struct))
@@ -244,18 +268,31 @@ fdt_set_hdr_(size_dt_struct);
 #undef fdt_set_hdr_
 
 /**
- * fdt_check_header - sanity check a device tree or possible device tree
+ * fdt_header_size - return the size of the tree's header
+ * @fdt: pointer to a flattened device tree
+ */
+size_t fdt_header_size_(uint32_t version);
+static inline size_t fdt_header_size(const void *fdt)
+{
+	return fdt_header_size_(fdt_version(fdt));
+}
+
+/**
+ * fdt_check_header - sanity check a device tree header
+
  * @fdt: pointer to data which might be a flattened device tree
  *
  * fdt_check_header() checks that the given buffer contains what
- * appears to be a flattened device tree with sane information in its
- * header.
+ * appears to be a flattened device tree, and that the header contains
+ * valid information (to the extent that can be determined from the
+ * header alone).
  *
  * returns:
  *     0, if the buffer appears to contain a valid device tree
  *     -FDT_ERR_BADMAGIC,
  *     -FDT_ERR_BADVERSION,
- *     -FDT_ERR_BADSTATE, standard meanings, as above
+ *     -FDT_ERR_BADSTATE,
+ *     -FDT_ERR_TRUNCATED, standard meanings, as above
  */
 int fdt_check_header(const void *fdt);
 
@@ -284,6 +321,24 @@ int fdt_move(const void *fdt, void *buf, int bufsize);
 /* Read-only functions                                                */
 /**********************************************************************/
 
+int fdt_check_full(const void *fdt, size_t bufsize);
+
+/**
+ * fdt_get_string - retrieve a string from the strings block of a device tree
+ * @fdt: pointer to the device tree blob
+ * @stroffset: offset of the string within the strings block (native endian)
+ * @lenp: optional pointer to return the string's length
+ *
+ * fdt_get_string() retrieves a pointer to a single string from the
+ * strings block of the device tree blob at fdt, and optionally also
+ * returns the string's length in *lenp.
+ *
+ * returns:
+ *     a pointer to the string, on success
+ *     NULL, if stroffset is out of bounds, or doesn't point to a valid string
+ */
+const char *fdt_get_string(const void *fdt, int stroffset, int *lenp);
+
 /**
  * fdt_string - retrieve a string from the strings block of a device tree
  * @fdt: pointer to the device tree blob
@@ -294,7 +349,7 @@ int fdt_move(const void *fdt, void *buf, int bufsize);
  *
  * returns:
  *     a pointer to the string, on success
- *     NULL, if stroffset is out of bounds
+ *     NULL, if stroffset is out of bounds, or doesn't point to a valid string
  */
 const char *fdt_string(const void *fdt, int stroffset);
 
@@ -1090,7 +1145,7 @@ int fdt_address_cells(const void *fdt, int nodeoffset);
  *
  * returns:
  *	0 <= n < FDT_MAX_NCELLS, on success
- *      2, if the node has no #address-cells property
+ *      2, if the node has no #size-cells property
  *      -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
  *		#size-cells property
  *	-FDT_ERR_BADMAGIC,
@@ -1313,10 +1368,13 @@ static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
 	fdt64_t tmp = cpu_to_fdt64(val);
 	return fdt_property(fdt, name, &tmp, sizeof(tmp));
 }
+
+#ifndef SWIG /* Not available in Python */
 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
 {
 	return fdt_property_u32(fdt, name, val);
 }
+#endif
 
 /**
  * fdt_property_placeholder - add a new property and return a ptr to its value
diff --git a/scripts/dtc/libfdt/libfdt_env.h b/scripts/dtc/libfdt/libfdt_env.h
index bd2474628775..eb2053845c9c 100644
--- a/scripts/dtc/libfdt/libfdt_env.h
+++ b/scripts/dtc/libfdt/libfdt_env.h
@@ -56,6 +56,7 @@
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
+#include <limits.h>
 
 #ifdef __CHECKER__
 #define FDT_FORCE __attribute__((force))
diff --git a/scripts/dtc/libfdt/libfdt_internal.h b/scripts/dtc/libfdt/libfdt_internal.h
index 7681e192295b..4109f890ae60 100644
--- a/scripts/dtc/libfdt/libfdt_internal.h
+++ b/scripts/dtc/libfdt/libfdt_internal.h
@@ -55,10 +55,11 @@
 #define FDT_ALIGN(x, a)		(((x) + (a) - 1) & ~((a) - 1))
 #define FDT_TAGALIGN(x)		(FDT_ALIGN((x), FDT_TAGSIZE))
 
-#define FDT_CHECK_HEADER(fdt) \
+int fdt_ro_probe_(const void *fdt);
+#define FDT_RO_PROBE(fdt)			\
 	{ \
 		int err_; \
-		if ((err_ = fdt_check_header(fdt)) != 0) \
+		if ((err_ = fdt_ro_probe_(fdt)) != 0)	\
 			return err_; \
 	}
 
diff --git a/scripts/dtc/livetree.c b/scripts/dtc/livetree.c
index 6e4c367f54b3..4ff0679e0062 100644
--- a/scripts/dtc/livetree.c
+++ b/scripts/dtc/livetree.c
@@ -594,6 +594,7 @@ struct node *get_node_by_ref(struct node *tree, const char *ref)
 cell_t get_node_phandle(struct node *root, struct node *node)
 {
 	static cell_t phandle = 1; /* FIXME: ick, static local */
+	struct data d = empty_data;
 
 	if ((node->phandle != 0) && (node->phandle != -1))
 		return node->phandle;
@@ -603,17 +604,16 @@ cell_t get_node_phandle(struct node *root, struct node *node)
 
 	node->phandle = phandle;
 
+	d = data_add_marker(d, TYPE_UINT32, NULL);
+	d = data_append_cell(d, phandle);
+
 	if (!get_property(node, "linux,phandle")
 	    && (phandle_format & PHANDLE_LEGACY))
-		add_property(node,
-			     build_property("linux,phandle",
-					    data_append_cell(empty_data, phandle)));
+		add_property(node, build_property("linux,phandle", d));
 
 	if (!get_property(node, "phandle")
 	    && (phandle_format & PHANDLE_EPAPR))
-		add_property(node,
-			     build_property("phandle",
-					    data_append_cell(empty_data, phandle)));
+		add_property(node, build_property("phandle", d));
 
 	/* If the node *does* have a phandle property, we must
 	 * be dealing with a self-referencing phandle, which will be
diff --git a/scripts/dtc/treesource.c b/scripts/dtc/treesource.c
index 2461a3d068a0..f2874f1d1465 100644
--- a/scripts/dtc/treesource.c
+++ b/scripts/dtc/treesource.c
@@ -61,24 +61,14 @@ static bool isstring(char c)
 		|| strchr("\a\b\t\n\v\f\r", c));
 }
 
-static void write_propval_string(FILE *f, struct data val)
+static void write_propval_string(FILE *f, const char *s, size_t len)
 {
-	const char *str = val.val;
-	int i;
-	struct marker *m = val.markers;
-
-	assert(str[val.len-1] == '\0');
+	const char *end = s + len - 1;
+	assert(*end == '\0');
 
-	while (m && (m->offset == 0)) {
-		if (m->type == LABEL)
-			fprintf(f, "%s: ", m->ref);
-		m = m->next;
-	}
 	fprintf(f, "\"");
-
-	for (i = 0; i < (val.len-1); i++) {
-		char c = str[i];
-
+	while (s < end) {
+		char c = *s++;
 		switch (c) {
 		case '\a':
 			fprintf(f, "\\a");
@@ -108,91 +98,78 @@ static void write_propval_string(FILE *f, struct data val)
 			fprintf(f, "\\\"");
 			break;
 		case '\0':
-			fprintf(f, "\", ");
-			while (m && (m->offset <= (i + 1))) {
-				if (m->type == LABEL) {
-					assert(m->offset == (i+1));
-					fprintf(f, "%s: ", m->ref);
-				}
-				m = m->next;
-			}
-			fprintf(f, "\"");
+			fprintf(f, "\\0");
 			break;
 		default:
 			if (isprint((unsigned char)c))
 				fprintf(f, "%c", c);
 			else
-				fprintf(f, "\\x%02hhx", c);
+				fprintf(f, "\\x%02"PRIx8, c);
 		}
 	}
 	fprintf(f, "\"");
-
-	/* Wrap up any labels at the end of the value */
-	for_each_marker_of_type(m, LABEL) {
-		assert (m->offset == val.len);
-		fprintf(f, " %s:", m->ref);
-	}
 }
 
-static void write_propval_cells(FILE *f, struct data val)
+static void write_propval_int(FILE *f, const char *p, size_t len, size_t width)
 {
-	void *propend = val.val + val.len;
-	fdt32_t *cp = (fdt32_t *)val.val;
-	struct marker *m = val.markers;
-
-	fprintf(f, "<");
-	for (;;) {
-		while (m && (m->offset <= ((char *)cp - val.val))) {
-			if (m->type == LABEL) {
-				assert(m->offset == ((char *)cp - val.val));
-				fprintf(f, "%s: ", m->ref);
-			}
-			m = m->next;
-		}
+	const char *end = p + len;
+	assert(len % width == 0);
 
-		fprintf(f, "0x%x", fdt32_to_cpu(*cp++));
-		if ((void *)cp >= propend)
+	for (; p < end; p += width) {
+		switch (width) {
+		case 1:
+			fprintf(f, " %02"PRIx8, *(const uint8_t*)p);
+			break;
+		case 2:
+			fprintf(f, " 0x%02"PRIx16, fdt16_to_cpu(*(const fdt16_t*)p));
+			break;
+		case 4:
+			fprintf(f, " 0x%02"PRIx32, fdt32_to_cpu(*(const fdt32_t*)p));
+			break;
+		case 8:
+			fprintf(f, " 0x%02"PRIx64, fdt64_to_cpu(*(const fdt64_t*)p));
 			break;
-		fprintf(f, " ");
+		}
 	}
+}
 
-	/* Wrap up any labels at the end of the value */
-	for_each_marker_of_type(m, LABEL) {
-		assert (m->offset == val.len);
-		fprintf(f, " %s:", m->ref);
-	}
-	fprintf(f, ">");
+static bool has_data_type_information(struct marker *m)
+{
+	return m->type >= TYPE_UINT8;
 }
 
-static void write_propval_bytes(FILE *f, struct data val)
+static struct marker *next_type_marker(struct marker *m)
 {
-	void *propend = val.val + val.len;
-	const char *bp = val.val;
-	struct marker *m = val.markers;
-
-	fprintf(f, "[");
-	for (;;) {
-		while (m && (m->offset == (bp-val.val))) {
-			if (m->type == LABEL)
-				fprintf(f, "%s: ", m->ref);
-			m = m->next;
-		}
+	while (m && !has_data_type_information(m))
+		m = m->next;
+	return m;
+}
 
-		fprintf(f, "%02hhx", (unsigned char)(*bp++));
-		if ((const void *)bp >= propend)
-			break;
-		fprintf(f, " ");
-	}
+size_t type_marker_length(struct marker *m)
+{
+	struct marker *next = next_type_marker(m->next);
 
-	/* Wrap up any labels at the end of the value */
-	for_each_marker_of_type(m, LABEL) {
-		assert (m->offset == val.len);
-		fprintf(f, " %s:", m->ref);
-	}
-	fprintf(f, "]");
+	if (next)
+		return next->offset - m->offset;
+	return 0;
 }
 
-static void write_propval(FILE *f, struct property *prop)
+static const char *delim_start[] = {
+	[TYPE_UINT8] = "[",
+	[TYPE_UINT16] = "/bits/ 16 <",
+	[TYPE_UINT32] = "<",
+	[TYPE_UINT64] = "/bits/ 64 <",
+	[TYPE_STRING] = "",
+};
+static const char *delim_end[] = {
+	[TYPE_UINT8] = " ]",
+	[TYPE_UINT16] = " >",
+	[TYPE_UINT32] = " >",
+	[TYPE_UINT64] = " >",
+	[TYPE_STRING] = "",
+};
+
+static enum markertype guess_value_type(struct property *prop)
 {
 	int len = prop->val.len;
 	const char *p = prop->val.val;
@@ -201,11 +178,6 @@ static void write_propval(FILE *f, struct property *prop)
 	int nnotstringlbl = 0, nnotcelllbl = 0;
 	int i;
 
-	if (len == 0) {
-		fprintf(f, ";\n");
-		return;
-	}
-
 	for (i = 0; i < len; i++) {
 		if (! isstring(p[i]))
 			nnotstring++;
@@ -220,17 +192,91 @@ static void write_propval(FILE *f, struct property *prop)
 			nnotcelllbl++;
 	}
 
-	fprintf(f, " = ");
 	if ((p[len-1] == '\0') && (nnotstring == 0) && (nnul < (len-nnul))
 	    && (nnotstringlbl == 0)) {
-		write_propval_string(f, prop->val);
+		return TYPE_STRING;
 	} else if (((len % sizeof(cell_t)) == 0) && (nnotcelllbl == 0)) {
-		write_propval_cells(f, prop->val);
-	} else {
-		write_propval_bytes(f, prop->val);
+		return TYPE_UINT32;
 	}
 
-	fprintf(f, ";\n");
+	return TYPE_UINT8;
+}
+
+static void write_propval(FILE *f, struct property *prop)
+{
+	size_t len = prop->val.len;
+	struct marker *m = prop->val.markers;
+	struct marker dummy_marker;
+	enum markertype emit_type = TYPE_NONE;
+
+	if (len == 0) {
+		fprintf(f, ";\n");
+		return;
+	}
+
+	fprintf(f, " = ");
+
+	if (!next_type_marker(m)) {
+		/* data type information missing, need to guess */
+		dummy_marker.type = guess_value_type(prop);
+		dummy_marker.next = prop->val.markers;
+		dummy_marker.offset = 0;
+		dummy_marker.ref = NULL;
+		m = &dummy_marker;
+	}
+
+	struct marker *m_label = prop->val.markers;
+	for_each_marker(m) {
+		size_t chunk_len;
+		const char *p = &prop->val.val[m->offset];
+
+		if (!has_data_type_information(m))
+			continue;
+
+		chunk_len = type_marker_length(m);
+		if (!chunk_len)
+			chunk_len = len - m->offset;
+
+		if (emit_type != TYPE_NONE)
+			fprintf(f, "%s, ", delim_end[emit_type]);
+		emit_type = m->type;
+
+		for_each_marker_of_type(m_label, LABEL) {
+			if (m_label->offset > m->offset)
+				break;
+			fprintf(f, "%s: ", m_label->ref);
+		}
+
+		fprintf(f, "%s", delim_start[emit_type]);
+
+		if (chunk_len <= 0)
+			continue;
+
+		switch(emit_type) {
+		case TYPE_UINT16:
+			write_propval_int(f, p, chunk_len, 2);
+			break;
+		case TYPE_UINT32:
+			write_propval_int(f, p, chunk_len, 4);
+			break;
+		case TYPE_UINT64:
+			write_propval_int(f, p, chunk_len, 8);
+			break;
+		case TYPE_STRING:
+			write_propval_string(f, p, chunk_len);
+			break;
+		default:
+			write_propval_int(f, p, chunk_len, 1);
+		}
+	}
+
+	/* Wrap up any labels at the end of the value */
+	for_each_marker_of_type(m_label, LABEL) {
+		assert (m_label->offset == len);
+		fprintf(f, " %s:", m_label->ref);
+	}
+
+	fprintf(f, "%s;\n", delim_end[emit_type] ? : "");
 }
 
 static void write_tree_source_node(FILE *f, struct node *tree, int level)
@@ -281,4 +327,3 @@ void dt_to_source(FILE *f, struct dt_info *dti)
 
 	write_tree_source_node(f, dti->dt, 0);
 }
-
diff --git a/scripts/dtc/util.c b/scripts/dtc/util.c
index 9953c32a0244..a69b7a13463d 100644
--- a/scripts/dtc/util.c
+++ b/scripts/dtc/util.c
@@ -227,11 +227,11 @@ char get_escape_char(const char *s, int *i)
 	return val;
 }
 
-int utilfdt_read_err_len(const char *filename, char **buffp, off_t *len)
+int utilfdt_read_err(const char *filename, char **buffp, size_t *len)
 {
 	int fd = 0;	/* assume stdin */
 	char *buf = NULL;
-	off_t bufsize = 1024, offset = 0;
+	size_t bufsize = 1024, offset = 0;
 	int ret = 0;
 
 	*buffp = NULL;
@@ -264,20 +264,15 @@ int utilfdt_read_err_len(const char *filename, char **buffp, off_t *len)
 		free(buf);
 	else
 		*buffp = buf;
-	*len = bufsize;
+	if (len)
+		*len = bufsize;
 	return ret;
 }
 
-int utilfdt_read_err(const char *filename, char **buffp)
-{
-	off_t len;
-	return utilfdt_read_err_len(filename, buffp, &len);
-}
-
-char *utilfdt_read_len(const char *filename, off_t *len)
+char *utilfdt_read(const char *filename, size_t *len)
 {
 	char *buff;
-	int ret = utilfdt_read_err_len(filename, &buff, len);
+	int ret = utilfdt_read_err(filename, &buff, len);
 
 	if (ret) {
 		fprintf(stderr, "Couldn't open blob from '%s': %s\n", filename,
@@ -288,12 +283,6 @@ char *utilfdt_read_len(const char *filename, off_t *len)
 	return buff;
 }
 
-char *utilfdt_read(const char *filename)
-{
-	off_t len;
-	return utilfdt_read_len(filename, &len);
-}
-
 int utilfdt_write_err(const char *filename, const void *blob)
 {
 	int fd = 1;	/* assume stdout */
diff --git a/scripts/dtc/util.h b/scripts/dtc/util.h
index 66fba8ea709b..f6cea8274174 100644
--- a/scripts/dtc/util.h
+++ b/scripts/dtc/util.h
@@ -98,16 +98,10 @@ char get_escape_char(const char *s, int *i);
  * stderr.
  *
  * @param filename	The filename to read, or - for stdin
- * @return Pointer to allocated buffer containing fdt, or NULL on error
- */
-char *utilfdt_read(const char *filename);
-
-/**
- * Like utilfdt_read(), but also passes back the size of the file read.
- *
  * @param len		If non-NULL, the amount of data we managed to read
+ * @return Pointer to allocated buffer containing fdt, or NULL on error
  */
-char *utilfdt_read_len(const char *filename, off_t *len);
+char *utilfdt_read(const char *filename, size_t *len);
 
 /**
  * Read a device tree file into a buffer. Does not report errors, but only
@@ -116,16 +110,10 @@ char *utilfdt_read_len(const char *filename, off_t *len);
  *
  * @param filename	The filename to read, or - for stdin
  * @param buffp		Returns pointer to buffer containing fdt
- * @return 0 if ok, else an errno value representing the error
- */
-int utilfdt_read_err(const char *filename, char **buffp);
-
-/**
- * Like utilfdt_read_err(), but also passes back the size of the file read.
- *
  * @param len		If non-NULL, the amount of data we managed to read
+ * @return 0 if ok, else an errno value representing the error
  */
-int utilfdt_read_err_len(const char *filename, char **buffp, off_t *len);
+int utilfdt_read_err(const char *filename, char **buffp, size_t *len);
 
 /**
  * Write a device tree buffer to a file. This will report any errors on
diff --git a/scripts/dtc/version_gen.h b/scripts/dtc/version_gen.h
index b00f14ff7a17..6d23fd095f16 100644
--- a/scripts/dtc/version_gen.h
+++ b/scripts/dtc/version_gen.h
@@ -1 +1 @@
-#define DTC_VERSION "DTC 1.4.6-g84e414b0"
+#define DTC_VERSION "DTC 1.4.7-gc86da84d"
diff --git a/scripts/dtc/yamltree.c b/scripts/dtc/yamltree.c
new file mode 100644
index 000000000000..a00285a5a9ec
--- /dev/null
+++ b/scripts/dtc/yamltree.c
@@ -0,0 +1,247 @@
+/*
+ * (C) Copyright Linaro, Ltd. 2018
+ * (C) Copyright Arm Holdings.  2017
+ * (C) Copyright David Gibson <dwg@au1.ibm.com>, IBM Corporation.  2005.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
+ *                                                                   USA
+ */
+
+#include <stdlib.h>
+#include <yaml.h>
+#include "dtc.h"
+#include "srcpos.h"
+
+char *yaml_error_name[] = {
+	[YAML_NO_ERROR] = "no error",
+	[YAML_MEMORY_ERROR] = "memory error",
+	[YAML_READER_ERROR] = "reader error",
+	[YAML_SCANNER_ERROR] = "scanner error",
+	[YAML_PARSER_ERROR] = "parser error",
+	[YAML_COMPOSER_ERROR] = "composer error",
+	[YAML_WRITER_ERROR] = "writer error",
+	[YAML_EMITTER_ERROR] = "emitter error",
+};
+
+#define yaml_emitter_emit_or_die(emitter, event) (			\
+{									\
+	if (!yaml_emitter_emit(emitter, event))				\
+		die("yaml '%s': %s in %s, line %i\n",			\
+		    yaml_error_name[(emitter)->error], 			\
+		    (emitter)->problem, __func__, __LINE__);		\
+})
+
+static void yaml_propval_int(yaml_emitter_t *emitter, struct marker *markers, char *data, int len, int width)
+{
+	yaml_event_t event;
+	void *tag;
+	int off, start_offset = markers->offset;
+
+	switch(width) {
+		case 1: tag = "!u8"; break;
+		case 2: tag = "!u16"; break;
+		case 4: tag = "!u32"; break;
+		case 8: tag = "!u64"; break;
+		default:
+			die("Invalid width %i", width);
+	}
+	assert(len % width == 0);
+
+	yaml_sequence_start_event_initialize(&event, NULL,
+		(yaml_char_t *)tag, width == 4, YAML_FLOW_SEQUENCE_STYLE);
+	yaml_emitter_emit_or_die(emitter, &event);
+
+	for (off = 0; off < len; off += width) {
+		char buf[32];
+		struct marker *m;
+		bool is_phandle = false;
+
+		switch(width) {
+		case 1:
+			sprintf(buf, "0x%"PRIx8, *(uint8_t*)(data + off));
+			break;
+		case 2:
+			sprintf(buf, "0x%"PRIx16, fdt16_to_cpu(*(fdt16_t*)(data + off)));
+			break;
+		case 4:
+			sprintf(buf, "0x%"PRIx32, fdt32_to_cpu(*(fdt32_t*)(data + off)));
+			m = markers;
+			is_phandle = false;
+			for_each_marker_of_type(m, REF_PHANDLE) {
+				if (m->offset == (start_offset + off)) {
+					is_phandle = true;
+					break;
+				}
+			}
+			break;
+		case 8:
+			sprintf(buf, "0x%"PRIx64, fdt64_to_cpu(*(fdt64_t*)(data + off)));
+			break;
+		}
+
+		if (is_phandle)
+			yaml_scalar_event_initialize(&event, NULL,
+				(yaml_char_t*)"!phandle", (yaml_char_t *)buf,
+				strlen(buf), 0, 0, YAML_PLAIN_SCALAR_STYLE);
+		else
+			yaml_scalar_event_initialize(&event, NULL,
+				(yaml_char_t*)YAML_INT_TAG, (yaml_char_t *)buf,
+				strlen(buf), 1, 1, YAML_PLAIN_SCALAR_STYLE);
+		yaml_emitter_emit_or_die(emitter, &event);
+	}
+
+	yaml_sequence_end_event_initialize(&event);
+	yaml_emitter_emit_or_die(emitter, &event);
+}
+
+static void yaml_propval_string(yaml_emitter_t *emitter, char *str, int len)
+{
+	yaml_event_t event;
+	int i;
+
+	assert(str[len-1] == '\0');
+
+	/* Make sure the entire string is in the lower 7-bit ascii range */
+	for (i = 0; i < len; i++)
+		assert(isascii(str[i]));
+
+	yaml_scalar_event_initialize(&event, NULL,
+		(yaml_char_t *)YAML_STR_TAG, (yaml_char_t*)str,
+		len-1, 0, 1, YAML_DOUBLE_QUOTED_SCALAR_STYLE);
+	yaml_emitter_emit_or_die(emitter, &event);
+}
+
+static void yaml_propval(yaml_emitter_t *emitter, struct property *prop)
+{
+	yaml_event_t event;
+	int len = prop->val.len;
+	struct marker *m = prop->val.markers;
+
+	/* Emit the property name */
+	yaml_scalar_event_initialize(&event, NULL,
+		(yaml_char_t *)YAML_STR_TAG, (yaml_char_t*)prop->name,
+		strlen(prop->name), 1, 1, YAML_PLAIN_SCALAR_STYLE);
+	yaml_emitter_emit_or_die(emitter, &event);
+
+	/* Boolean properties are easiest to deal with. Length is zero, so just emit 'true' */
+	if (len == 0) {
+		yaml_scalar_event_initialize(&event, NULL,
+			(yaml_char_t *)YAML_BOOL_TAG,
+			(yaml_char_t*)"true",
+			strlen("true"), 1, 0, YAML_PLAIN_SCALAR_STYLE);
+		yaml_emitter_emit_or_die(emitter, &event);
+		return;
+	}
+
+	if (!m)
+		die("No markers present in property '%s' value\n", prop->name);
+
+	yaml_sequence_start_event_initialize(&event, NULL,
+		(yaml_char_t *)YAML_SEQ_TAG, 1, YAML_FLOW_SEQUENCE_STYLE);
+	yaml_emitter_emit_or_die(emitter, &event);
+
+	for_each_marker(m) {
+		int chunk_len;
+		char *data = &prop->val.val[m->offset];
+
+		if (m->type < TYPE_UINT8)
+			continue;
+
+		chunk_len = type_marker_length(m) ? : len;
+		assert(chunk_len > 0);
+		len -= chunk_len;
+
+		switch(m->type) {
+		case TYPE_UINT16:
+			yaml_propval_int(emitter, m, data, chunk_len, 2);
+			break;
+		case TYPE_UINT32:
+			yaml_propval_int(emitter, m, data, chunk_len, 4);
+			break;
+		case TYPE_UINT64:
+			yaml_propval_int(emitter, m, data, chunk_len, 8);
+			break;
+		case TYPE_STRING:
+			yaml_propval_string(emitter, data, chunk_len);
+			break;
+		default:
+			yaml_propval_int(emitter, m, data, chunk_len, 1);
+			break;
+		}
+	}
+
+	yaml_sequence_end_event_initialize(&event);
+	yaml_emitter_emit_or_die(emitter, &event);
+}
+
+
+static void yaml_tree(struct node *tree, yaml_emitter_t *emitter)
+{
+	struct property *prop;
+	struct node *child;
+	yaml_event_t event;
+
+	if (tree->deleted)
+		return;
+
+	yaml_mapping_start_event_initialize(&event, NULL,
+		(yaml_char_t *)YAML_MAP_TAG, 1, YAML_ANY_MAPPING_STYLE);
+	yaml_emitter_emit_or_die(emitter, &event);
+
+	for_each_property(tree, prop)
+		yaml_propval(emitter, prop);
+
+	/* Loop over all the children, emitting them into the map */
+	for_each_child(tree, child) {
+		yaml_scalar_event_initialize(&event, NULL,
+			(yaml_char_t *)YAML_STR_TAG, (yaml_char_t*)child->name,
+			strlen(child->name), 1, 0, YAML_PLAIN_SCALAR_STYLE);
+		yaml_emitter_emit_or_die(emitter, &event);
+		yaml_tree(child, emitter);
+	}
+
+	yaml_mapping_end_event_initialize(&event);
+	yaml_emitter_emit_or_die(emitter, &event);
+}
+
+void dt_to_yaml(FILE *f, struct dt_info *dti)
+{
+	yaml_emitter_t emitter;
+	yaml_event_t event;
+
+	yaml_emitter_initialize(&emitter);
+	yaml_emitter_set_output_file(&emitter, f);
+	yaml_stream_start_event_initialize(&event, YAML_UTF8_ENCODING);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_document_start_event_initialize(&event, NULL, NULL, NULL, 0);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_sequence_start_event_initialize(&event, NULL, (yaml_char_t *)YAML_SEQ_TAG, 1, YAML_ANY_SEQUENCE_STYLE);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_tree(dti->dt, &emitter);
+
+	yaml_sequence_end_event_initialize(&event);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_document_end_event_initialize(&event, 0);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_stream_end_event_initialize(&event);
+	yaml_emitter_emit_or_die(&emitter, &event);
+
+	yaml_emitter_delete(&emitter);
+}
-- 
2.17.1

^ permalink raw reply related

* [PATCH] Correct PowerPC VDSO call frame info
From: Alan Modra @ 2018-09-13 23:27 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Paul Mackerras, Michael Ellerman, Michael Neuling

There is control flow in __kernel_clock_gettime that reaches label 99
without saving lr in r12.  CFI info however is interpreted by the
unwinder without reference to control flow: It's a simple matter of
"Execute all the CFI opcodes up to the current address".  That means
the unwinder thinks r12 contains the return address at label 99.
Disabuse it of that notion by resetting CFI for the return address at
label 99.

Note that the ".cfi_restore lr" could have gone anywhere from the
"mtlr r12" a few instructions earlier to the instruction at label 99.
I put the CFI as late as possible, because in general that's best
practice (and if possible grouped with other CFI in order to reduce
the number of CFI opcodes executed when unwinding).  Using r12 as the
return address is perfectly fine after the "mtlr r12" since r12 on
that code path still contains the return address.

__get_datapage also has a CFI error.  That function temporarily saves
lr in r0, and reflects that fact with ".cfi_register lr,r0".  A later
use of r0 means the CFI at that point isn't correct, as r0 no longer
contains the return address.  Fix that too.

Signed-off-by: Alan Modra <amodra@gmail.com>

diff --git a/arch/powerpc/kernel/vdso32/datapage.S b/arch/powerpc/kernel/vdso32/datapage.S
index 3745113fcc65..2a7eb5452aba 100644
--- a/arch/powerpc/kernel/vdso32/datapage.S
+++ b/arch/powerpc/kernel/vdso32/datapage.S
@@ -37,6 +37,7 @@ data_page_branch:
 	mtlr	r0
 	addi	r3, r3, __kernel_datapage_offset-data_page_branch
 	lwz	r0,0(r3)
+  .cfi_restore lr
 	add	r3,r0,r3
 	blr
   .cfi_endproc
diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
index 769c2624e0a6..1e0bc5955a40 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -139,6 +139,7 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
 	 */
 99:
 	li	r0,__NR_clock_gettime
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc
diff --git a/arch/powerpc/kernel/vdso64/datapage.S b/arch/powerpc/kernel/vdso64/datapage.S
index abf17feffe40..bf9668691511 100644
--- a/arch/powerpc/kernel/vdso64/datapage.S
+++ b/arch/powerpc/kernel/vdso64/datapage.S
@@ -37,6 +37,7 @@ data_page_branch:
 	mtlr	r0
 	addi	r3, r3, __kernel_datapage_offset-data_page_branch
 	lwz	r0,0(r3)
+  .cfi_restore lr
 	add	r3,r0,r3
 	blr
   .cfi_endproc
diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
index c002adcc694c..a4ed9edfd5f0 100644
--- a/arch/powerpc/kernel/vdso64/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
@@ -169,6 +169,7 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
 	 */
 99:
 	li	r0,__NR_clock_gettime
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc

-- 
Alan Modra
Australia Development Lab, IBM

^ permalink raw reply related

* Re: [PATCH] Correct PowerPC VDSO call frame info
From: Michael Neuling @ 2018-09-14  0:01 UTC (permalink / raw)
  To: Alan Modra, linuxppc-dev
In-Reply-To: <20180913232704.GL3174@bubble.grove.modra.org>

Alan,

Thanks for the patch... A few minor comments...

> Re: [PATCH] Correct PowerPC VDSO call frame info

Our convention is to add powerpc: to the start. ie

  [PATCH] powerpc: Correct VDSO call frame info

or even:=20

  [PATCH] powerpc/vdso: Correct call frame info


On Fri, 2018-09-14 at 08:57 +0930, Alan Modra wrote:
> There is control flow in __kernel_clock_gettime that reaches label 99
> without saving lr in r12.  CFI info however is interpreted by the
> unwinder without reference to control flow: It's a simple matter of
> "Execute all the CFI opcodes up to the current address".  That means
> the unwinder thinks r12 contains the return address at label 99.
> Disabuse it of that notion by resetting CFI for the return address at
> label 99.

Can you expand on CFI =3D=3D Call Frame Information in the commit message. =
 Not a
common term for us mere kernel developers?

> Note that the ".cfi_restore lr" could have gone anywhere from the
> "mtlr r12" a few instructions earlier to the instruction at label 99.
> I put the CFI as late as possible, because in general that's best
> practice (and if possible grouped with other CFI in order to reduce
> the number of CFI opcodes executed when unwinding).  Using r12 as the
> return address is perfectly fine after the "mtlr r12" since r12 on
> that code path still contains the return address.
>=20
> __get_datapage also has a CFI error.  That function temporarily saves
> lr in r0, and reflects that fact with ".cfi_register lr,r0".  A later
> use of r0 means the CFI at that point isn't correct, as r0 no longer
> contains the return address.  Fix that too.

Can you describe the problem this fixes at a high level?  ie This fixes doi=
ng a
stack unwind with gdb when in __kernel_clock_gettime.

Mikey

> Signed-off-by: Alan Modra <amodra@gmail.com>
>=20
> diff --git a/arch/powerpc/kernel/vdso32/datapage.S
> b/arch/powerpc/kernel/vdso32/datapage.S
> index 3745113fcc65..2a7eb5452aba 100644
> --- a/arch/powerpc/kernel/vdso32/datapage.S
> +++ b/arch/powerpc/kernel/vdso32/datapage.S
> @@ -37,6 +37,7 @@ data_page_branch:
>  	mtlr	r0
>  	addi	r3, r3, __kernel_datapage_offset-data_page_branch
>  	lwz	r0,0(r3)
> +  .cfi_restore lr
>  	add	r3,r0,r3
>  	blr
>    .cfi_endproc
> diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S
> b/arch/powerpc/kernel/vdso32/gettimeofday.S
> index 769c2624e0a6..1e0bc5955a40 100644
> --- a/arch/powerpc/kernel/vdso32/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
> @@ -139,6 +139,7 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
>  	 */
>  99:
>  	li	r0,__NR_clock_gettime
> +  .cfi_restore lr
>  	sc
>  	blr
>    .cfi_endproc
> diff --git a/arch/powerpc/kernel/vdso64/datapage.S
> b/arch/powerpc/kernel/vdso64/datapage.S
> index abf17feffe40..bf9668691511 100644
> --- a/arch/powerpc/kernel/vdso64/datapage.S
> +++ b/arch/powerpc/kernel/vdso64/datapage.S
> @@ -37,6 +37,7 @@ data_page_branch:
>  	mtlr	r0
>  	addi	r3, r3, __kernel_datapage_offset-data_page_branch
>  	lwz	r0,0(r3)
> +  .cfi_restore lr
>  	add	r3,r0,r3
>  	blr
>    .cfi_endproc
> diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S
> b/arch/powerpc/kernel/vdso64/gettimeofday.S
> index c002adcc694c..a4ed9edfd5f0 100644
> --- a/arch/powerpc/kernel/vdso64/gettimeofday.S
> +++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
> @@ -169,6 +169,7 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
>  	 */
>  99:
>  	li	r0,__NR_clock_gettime
> +  .cfi_restore lr
>  	sc
>  	blr
>    .cfi_endproc
>=20

^ permalink raw reply

* Re: [PATCH] MAINTAINERS: Add PPC contacts for PCI core error handling
From: Sam Bobroff @ 2018-09-14  0:05 UTC (permalink / raw)
  To: Russell Currey
  Cc: Bjorn Helgaas, linux-pci, linuxppc-dev, Benjamin Herrenschmidt,
	Paul Mackerras, Michael Ellerman, linux-kernel, oohall
In-Reply-To: <94b8929d44af6dd965600b7d159458312d500582.camel@russell.cc>

[-- Attachment #1: Type: text/plain, Size: 2409 bytes --]

On Thu, Sep 13, 2018 at 12:26:55PM +1000, Russell Currey wrote:
> On Wed, 2018-09-12 at 11:58 -0500, Bjorn Helgaas wrote:
> > On Wed, Sep 12, 2018 at 11:55:26AM -0500, Bjorn Helgaas wrote:
> > > From: Bjorn Helgaas <bhelgaas@google.com>
> > > 
> > > The original PCI error recovery functionality was for the powerpc-specific
> > > IBM EEH feature.  PCIe subsequently added some similar features, including
> > > AER and DPC, that can be used on any architecture.
> > > 
> > > We want the generic PCI core error handling support to work with all of
> > > these features.  Driver error recovery callbacks should be independent of
> > > which feature the platform provides.
> > > 
> > > Add the generic PCI core error recovery files to the powerpc EEH
> > > MAINTAINERS entry so the powerpc folks will be copied on changes to the
> > > generic PCI error handling strategy.
> > 
> > I really want to make sure the powerpc folks are plugged into any PCI core
> > error handling discussions.  Please let me know if there's a better way
> > than this patch, or if there are other people who should be added.
> 
> I think this patch is definitely a good idea.
> 
> Alongside this (whether you want to include it in your patch or not, Bjorn),
> Sam Bobroff should replace myself as maintainer.  He's been very active in fixing,
> reworking and reviewing in EEH land and will probably do a better job of keeping
> his finger on the pulse of the generic PCI error handling code than I did.
> 
> - Russell

That's fine with me. You can add me or let me know if I should send a
patch.

Sam.

> 
> > 
> > > Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
> > > ---
> > >  MAINTAINERS |    4 ++++
> > >  1 file changed, 4 insertions(+)
> > > 
> > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > index 7e10ba65bfe4..d6699597fd89 100644
> > > --- a/MAINTAINERS
> > > +++ b/MAINTAINERS
> > > @@ -11202,6 +11202,10 @@ PCI ENHANCED ERROR HANDLING (EEH) FOR POWERPC
> > >  M:	Russell Currey <ruscur@russell.cc>
> > >  L:	linuxppc-dev@lists.ozlabs.org
> > >  S:	Supported
> > > +F:	Documentation/PCI/pci-error-recovery.txt
> > > +F:	drivers/pci/pcie/aer.c
> > > +F:	drivers/pci/pcie/dpc.c
> > > +F:	drivers/pci/pcie/err.c
> > >  F:	Documentation/powerpc/eeh-pci-error-recovery.txt
> > >  F:	arch/powerpc/kernel/eeh*.c
> > >  F:	arch/powerpc/platforms/*/eeh*.c
> > > 
> 

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^ permalink raw reply

* [PATCH v4] powerpc: Avoid code patching freed init sections
From: Michael Neuling @ 2018-09-14  1:14 UTC (permalink / raw)
  To: mpe
  Cc: linuxppc-dev, Nicholas Piggin, paulus, Haren Myneni, mikey,
	Michal Suchánek, Christophe LEROY

This stops us from doing code patching in init sections after they've
been freed.

In this chain:
  kvm_guest_init() ->
    kvm_use_magic_page() ->
      fault_in_pages_readable() ->
	 __get_user() ->
	   __get_user_nocheck() ->
	     barrier_nospec();

We have a code patching location at barrier_nospec() and
kvm_guest_init() is an init function. This whole chain gets inlined,
so when we free the init section (hence kvm_guest_init()), this code
goes away and hence should no longer be patched.

We seen this as userspace memory corruption when using a memory
checker while doing partition migration testing on powervm (this
starts the code patching post migration via
/sys/kernel/mobility/migration). In theory, it could also happen when
using /sys/kernel/debug/powerpc/barrier_nospec.

cc: stable@vger.kernel.org # 4.13+
Signed-off-by: Michael Neuling <mikey@neuling.org>

---
For stable I've marked this as v4.13+ since that's when we refactored
code-patching.c but it could go back even further than that. In
reality though, I think we can only hit this since the first
spectre/meltdown changes.

v4:
 Feedback from Christophe Leroy:
   - init_mem_free -> init_mem_is_free
   - prlog %lx -> %px

v3:
 Add init_mem_free flag to avoid potential race.
 Feedback from Christophe Leroy:
   - use init_section_contains()
   - change order of init test for performance
   - use pr_debug()
   - remove blank line

v2:
  Print when we skip an address
---
 arch/powerpc/include/asm/setup.h | 1 +
 arch/powerpc/lib/code-patching.c | 6 ++++++
 arch/powerpc/mm/mem.c            | 2 ++
 3 files changed, 9 insertions(+)

diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
index 1a951b0046..1fffbba8d6 100644
--- a/arch/powerpc/include/asm/setup.h
+++ b/arch/powerpc/include/asm/setup.h
@@ -9,6 +9,7 @@ extern void ppc_printk_progress(char *s, unsigned short hex);
 
 extern unsigned int rtas_data;
 extern unsigned long long memory_limit;
+extern bool init_mem_is_free;
 extern unsigned long klimit;
 extern void *zalloc_maybe_bootmem(size_t size, gfp_t mask);
 
diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
index 850f3b8f4d..6ae2777c22 100644
--- a/arch/powerpc/lib/code-patching.c
+++ b/arch/powerpc/lib/code-patching.c
@@ -28,6 +28,12 @@ static int __patch_instruction(unsigned int *exec_addr, unsigned int instr,
 {
 	int err;
 
+	/* Make sure we aren't patching a freed init section */
+	if (init_mem_is_free && init_section_contains(exec_addr, 4)) {
+		pr_debug("Skipping init section patching addr: 0x%px\n", exec_addr);
+		return 0;
+	}
+
 	__put_user_size(instr, patch_addr, 4, err);
 	if (err)
 		return err;
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 5c8530d0c6..04ccb274a6 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -63,6 +63,7 @@
 #endif
 
 unsigned long long memory_limit;
+bool init_mem_is_free;
 
 #ifdef CONFIG_HIGHMEM
 pte_t *kmap_pte;
@@ -396,6 +397,7 @@ void free_initmem(void)
 {
 	ppc_md.progress = ppc_printk_progress;
 	mark_initmem_nx();
+	init_mem_is_free = true;
 	free_initmem_default(POISON_FREE_INITMEM);
 }
 
-- 
2.17.1

^ permalink raw reply related

* [PATCH v4] powerpc/64s: reimplement book3s idle code in C
From: Nicholas Piggin @ 2018-09-14  1:52 UTC (permalink / raw)
  To: linuxppc-dev
  Cc: Nicholas Piggin, kvm-ppc, Gautham R . Shenoy,
	Mahesh Jagannath Salgaonkar, Aneesh Kumar K.V, Akshay Adiga

Reimplement Book3S idle code in C, moving POWER7/8/9 implementation
speific HV idle code to the powernv platform code.

Book3S assembly stubs are kept in common code and used only to save
the stack frame and non-volatile GPRs before executing architected
idle instructions, and restoring the stack and reloading GPRs then
returning to C after waking from idle.

The complex logic dealing with threads and subcores, locking, SPRs,
HMIs, timebase resync, etc., is all done in C which makes it more
maintainable.

This is not a strict translation to C code, there are some
significant differences:

- Idle wakeup no longer uses the ->cpu_restore call to reinit SPRs,
  but saves and restores them itself.

- The optimisation where EC=ESL=0 idle modes did not have to save GPRs
  or change MSR is restored, because it's now simple to do. ESL=1
  sleeps that do not lose GPRs can use this optimization too.

- KVM secondary entry and cede is now more of a call/return style
  rather than branchy. nap_state_lost is not required because KVM
  always returns via NVGPR restoring path.

Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

- P9 restores some of the PMU SPRs, but not others, and P8 only zeroes
  them. There are improvmets to be made to SPR save restore policies and
  documentation, but this first pass tries to keep things as they were.

Left to do:
- Test actual POWER7 hardware.

- KVM could use more review, it's pretty tricky. Not sure if what
  I'm doing with the emergency stack is kosher. But it runs pretty fine
  here with a POWER8 SMP+SMT guest. Possible to streamline
  KVM cede code now that idle function saves nv gprs for us?

Since RFC v1:
- Now tested and working with POWER9 hash and radix.
- KVM support added. This took a bit of work to untangle and might
  still have some issues, but POWER9 seems to work including hash on
  radix with dependent threads mode.
- This snowballed a bit because of KVM and other details making it
  not feasible to leave POWER7/8 code alone. That's only half done
  at the moment.
- So far this trades about 800 lines of asm for 500 of C. With POWER7/8
  support done it might be another hundred or so lines of C.

Since RFC v2:
- Fixed deep state SLB reloading
- Now tested and working with POWER8.
- Accounted for most feedback.

Since RFC v3:
- Rebased to powerpc merge + idle state bugfix
- Split SLB flush/restore code out and shared with MCE code (pseries
  MCE patches can also use).
- More testing on POWER8 including KVM with secondaries.
- Performance testing looks good. EC=ESL=0 is about 5% faster, other
  stop states look a little faster too.
- Adjusted SPR saving to handler POWER7, haven't tested it.

Since submission v1:
- More review comments from Gautham.
- Rename isa3_ to isa300_ prefix.
- Tinkered with some comments, copyright notice, changelog.
- Cede and regular idle do not go via KVM secondary wakeup code path,
  so hwthread_state stores and barriers can be simplified, and some
  KVM code paths simplified a little.

Since v2:
- Rebase, SLB reload patch has been merged.
- More testing. Tested machine check idle wakeup path with mambo stepping
  through instructions.

Since v3:
- Build fixes caught by CI
---
 arch/powerpc/include/asm/cpuidle.h       |   19 +-
 arch/powerpc/include/asm/paca.h          |   38 +-
 arch/powerpc/include/asm/processor.h     |    9 +-
 arch/powerpc/include/asm/reg.h           |    7 +-
 arch/powerpc/kernel/asm-offsets.c        |   18 -
 arch/powerpc/kernel/dt_cpu_ftrs.c        |   21 +-
 arch/powerpc/kernel/exceptions-64s.S     |   17 +-
 arch/powerpc/kernel/idle_book3s.S        | 1012 +++-------------------
 arch/powerpc/kernel/setup-common.c       |    4 +-
 arch/powerpc/kvm/book3s_hv_rmhandlers.S  |   86 +-
 arch/powerpc/platforms/powernv/idle.c    |  828 ++++++++++++++----
 arch/powerpc/platforms/powernv/subcore.c |    2 +-
 arch/powerpc/xmon/xmon.c                 |   24 +-
 13 files changed, 880 insertions(+), 1205 deletions(-)

diff --git a/arch/powerpc/include/asm/cpuidle.h b/arch/powerpc/include/asm/cpuidle.h
index 43e5f31fe64d..9844b3ded187 100644
--- a/arch/powerpc/include/asm/cpuidle.h
+++ b/arch/powerpc/include/asm/cpuidle.h
@@ -27,10 +27,11 @@
  * the THREAD_WINKLE_BITS are set, which indicate which threads have not
  * yet woken from the winkle state.
  */
-#define PNV_CORE_IDLE_LOCK_BIT			0x10000000
+#define NR_PNV_CORE_IDLE_LOCK_BIT		28
+#define PNV_CORE_IDLE_LOCK_BIT			(1ULL << NR_PNV_CORE_IDLE_LOCK_BIT)
 
+#define PNV_CORE_IDLE_WINKLE_COUNT_SHIFT	16
 #define PNV_CORE_IDLE_WINKLE_COUNT		0x00010000
-#define PNV_CORE_IDLE_WINKLE_COUNT_ALL_BIT	0x00080000
 #define PNV_CORE_IDLE_WINKLE_COUNT_BITS		0x000F0000
 #define PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT	8
 #define PNV_CORE_IDLE_THREAD_WINKLE_BITS	0x0000FF00
@@ -68,16 +69,6 @@
 #define ERR_DEEP_STATE_ESL_MISMATCH	-2
 
 #ifndef __ASSEMBLY__
-/* Additional SPRs that need to be saved/restored during stop */
-struct stop_sprs {
-	u64 pid;
-	u64 ldbar;
-	u64 fscr;
-	u64 hfscr;
-	u64 mmcr1;
-	u64 mmcr2;
-	u64 mmcra;
-};
 
 #define PNV_IDLE_NAME_LEN    16
 struct pnv_idle_states_t {
@@ -92,10 +83,6 @@ struct pnv_idle_states_t {
 
 extern struct pnv_idle_states_t *pnv_idle_states;
 extern int nr_pnv_idle_states;
-extern u32 pnv_fastsleep_workaround_at_entry[];
-extern u32 pnv_fastsleep_workaround_at_exit[];
-
-extern u64 pnv_first_deep_stop_state;
 
 unsigned long pnv_cpu_offline(unsigned int cpu);
 int validate_psscr_val_mask(u64 *psscr_val, u64 *psscr_mask, u32 flags);
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index ad4f16164619..4331295db0f7 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -168,7 +168,6 @@ struct paca_struct {
 	u8 irq_happened;		/* irq happened while soft-disabled */
 	u8 io_sync;			/* writel() needs spin_unlock sync */
 	u8 irq_work_pending;		/* IRQ_WORK interrupt while soft-disable */
-	u8 nap_state_lost;		/* NV GPR values lost in power7_idle */
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 	u8 pmcregs_in_use;		/* pseries puts this in lppaca */
 #endif
@@ -178,23 +177,28 @@ struct paca_struct {
 #endif
 
 #ifdef CONFIG_PPC_POWERNV
-	/* Per-core mask tracking idle threads and a lock bit-[L][TTTTTTTT] */
-	u32 *core_idle_state_ptr;
-	u8 thread_idle_state;		/* PNV_THREAD_RUNNING/NAP/SLEEP	*/
-	/* Mask to indicate thread id in core */
-	u8 thread_mask;
-	/* Mask to denote subcore sibling threads */
-	u8 subcore_sibling_mask;
-	/* Flag to request this thread not to stop */
-	atomic_t dont_stop;
-	/* The PSSCR value that the kernel requested before going to stop */
-	u64 requested_psscr;
+	/* PowerNV idle fields */
+	/* PNV_CORE_IDLE_* bits, all siblings work on thread 0 paca */
+	unsigned long idle_state;
+	union {
+		/* P7/P8 specific fields */
+		struct {
+			/* PNV_THREAD_RUNNING/NAP/SLEEP	*/
+			u8 thread_idle_state;
+			/* Mask to denote subcore sibling threads */
+			u8 subcore_sibling_mask;
+		};
 
-	/*
-	 * Save area for additional SPRs that need to be
-	 * saved/restored during cpuidle stop.
-	 */
-	struct stop_sprs stop_sprs;
+		/* P9 specific fields */
+		struct {
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+			/* The PSSCR value that the kernel requested before going to stop */
+			u64 requested_psscr;
+			/* Flag to request this thread not to stop */
+			atomic_t dont_stop;
+#endif
+		};
+	};
 #endif
 
 #ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/include/asm/processor.h b/arch/powerpc/include/asm/processor.h
index 52fadded5c1e..12b76ecdc57d 100644
--- a/arch/powerpc/include/asm/processor.h
+++ b/arch/powerpc/include/asm/processor.h
@@ -506,14 +506,17 @@ static inline unsigned long get_clean_sp(unsigned long sp, int is_32)
 }
 #endif
 
+/* asm stubs */
+extern unsigned long isa300_idle_stop_noloss(unsigned long psscr_val);
+extern unsigned long isa300_idle_stop_mayloss(unsigned long psscr_val);
+extern unsigned long isa206_idle_insn_mayloss(unsigned long type);
+
 extern unsigned long cpuidle_disable;
 enum idle_boot_override {IDLE_NO_OVERRIDE = 0, IDLE_POWERSAVE_OFF};
 
 extern int powersave_nap;	/* set if nap mode can be used in idle loop */
-extern unsigned long power7_idle_insn(unsigned long type); /* PNV_THREAD_NAP/etc*/
+
 extern void power7_idle_type(unsigned long type);
-extern unsigned long power9_idle_stop(unsigned long psscr_val);
-extern unsigned long power9_offline_stop(unsigned long psscr_val);
 extern void power9_idle_type(unsigned long stop_psscr_val,
 			      unsigned long stop_psscr_mask);
 
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index e5b314ed054e..fa4bc5bb6101 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -752,10 +752,9 @@
 #define	  SRR1_WAKERESET	0x00100000 /* System reset */
 #define   SRR1_WAKEHDBELL	0x000c0000 /* Hypervisor doorbell on P8 */
 #define	  SRR1_WAKESTATE	0x00030000 /* Powersave exit mask [46:47] */
-#define	  SRR1_WS_DEEPEST	0x00030000 /* Some resources not maintained,
-					  * may not be recoverable */
-#define	  SRR1_WS_DEEPER	0x00020000 /* Some resources not maintained */
-#define	  SRR1_WS_DEEP		0x00010000 /* All resources maintained */
+#define	  SRR1_WS_HVLOSS	0x00030000 /* HV resources not maintained */
+#define	  SRR1_WS_GPRLOSS	0x00020000 /* GPRs not maintained */
+#define	  SRR1_WS_NOLOSS	0x00010000 /* All resources maintained */
 #define   SRR1_PROGTM		0x00200000 /* TM Bad Thing */
 #define   SRR1_PROGFPE		0x00100000 /* Floating Point Enabled */
 #define   SRR1_PROGILL		0x00080000 /* Illegal instruction */
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 89cf15566c4e..7834256585f1 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -256,7 +256,6 @@ int main(void)
 	OFFSET(ACCOUNT_USER_TIME, paca_struct, accounting.utime);
 	OFFSET(ACCOUNT_SYSTEM_TIME, paca_struct, accounting.stime);
 	OFFSET(PACA_TRAP_SAVE, paca_struct, trap_save);
-	OFFSET(PACA_NAPSTATELOST, paca_struct, nap_state_lost);
 	OFFSET(PACA_SPRG_VDSO, paca_struct, sprg_vdso);
 #else /* CONFIG_PPC64 */
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
@@ -761,23 +760,6 @@ int main(void)
 	OFFSET(VCPU_TIMING_LAST_ENTER_TBL, kvm_vcpu, arch.timing_last_enter.tv32.tbl);
 #endif
 
-#ifdef CONFIG_PPC_POWERNV
-	OFFSET(PACA_CORE_IDLE_STATE_PTR, paca_struct, core_idle_state_ptr);
-	OFFSET(PACA_THREAD_IDLE_STATE, paca_struct, thread_idle_state);
-	OFFSET(PACA_THREAD_MASK, paca_struct, thread_mask);
-	OFFSET(PACA_SUBCORE_SIBLING_MASK, paca_struct, subcore_sibling_mask);
-	OFFSET(PACA_REQ_PSSCR, paca_struct, requested_psscr);
-	OFFSET(PACA_DONT_STOP, paca_struct, dont_stop);
-#define STOP_SPR(x, f)	OFFSET(x, paca_struct, stop_sprs.f)
-	STOP_SPR(STOP_PID, pid);
-	STOP_SPR(STOP_LDBAR, ldbar);
-	STOP_SPR(STOP_FSCR, fscr);
-	STOP_SPR(STOP_HFSCR, hfscr);
-	STOP_SPR(STOP_MMCR1, mmcr1);
-	STOP_SPR(STOP_MMCR2, mmcr2);
-	STOP_SPR(STOP_MMCRA, mmcra);
-#endif
-
 	DEFINE(PPC_DBELL_SERVER, PPC_DBELL_SERVER);
 	DEFINE(PPC_DBELL_MSGTYPE, PPC_DBELL_MSGTYPE);
 
diff --git a/arch/powerpc/kernel/dt_cpu_ftrs.c b/arch/powerpc/kernel/dt_cpu_ftrs.c
index f432054234a4..d635d78facdc 100644
--- a/arch/powerpc/kernel/dt_cpu_ftrs.c
+++ b/arch/powerpc/kernel/dt_cpu_ftrs.c
@@ -71,7 +71,6 @@ static int hv_mode;
 
 static struct {
 	u64	lpcr;
-	u64	lpcr_clear;
 	u64	hfscr;
 	u64	fscr;
 } system_registers;
@@ -80,24 +79,7 @@ static void (*init_pmu_registers)(void);
 
 static void __restore_cpu_cpufeatures(void)
 {
-	u64 lpcr;
-
-	/*
-	 * LPCR is restored by the power on engine already. It can be changed
-	 * after early init e.g., by radix enable, and we have no unified API
-	 * for saving and restoring such SPRs.
-	 *
-	 * This ->restore hook should really be removed from idle and register
-	 * restore moved directly into the idle restore code, because this code
-	 * doesn't know how idle is implemented or what it needs restored here.
-	 *
-	 * The best we can do to accommodate secondary boot and idle restore
-	 * for now is "or" LPCR with existing.
-	 */
-	lpcr = mfspr(SPRN_LPCR);
-	lpcr |= system_registers.lpcr;
-	lpcr &= ~system_registers.lpcr_clear;
-	mtspr(SPRN_LPCR, lpcr);
+	mtspr(SPRN_LPCR, system_registers.lpcr);
 	if (hv_mode) {
 		mtspr(SPRN_LPID, 0);
 		mtspr(SPRN_HFSCR, system_registers.hfscr);
@@ -318,7 +300,6 @@ static int __init feat_enable_mmu_hash_v3(struct dt_cpu_feature *f)
 {
 	u64 lpcr;
 
-	system_registers.lpcr_clear |= (LPCR_ISL | LPCR_UPRT | LPCR_HR);
 	lpcr = mfspr(SPRN_LPCR);
 	lpcr &= ~(LPCR_ISL | LPCR_UPRT | LPCR_HR);
 	mtspr(SPRN_LPCR, lpcr);
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index ea04dfb8c092..9dad73722d1a 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -136,8 +136,9 @@ TRAMP_KVM(PACA_EXNMI, 0x100)
 
 #ifdef CONFIG_PPC_P7_NAP
 EXC_COMMON_BEGIN(system_reset_idle_common)
-	mfspr	r12,SPRN_SRR1
-	b	pnv_powersave_wakeup
+	mfspr	r3,SPRN_SRR1
+	bltlr	cr3	/* no state loss, return to idle caller */
+	b	idle_return_gpr_loss
 #endif
 
 /*
@@ -416,17 +417,17 @@ EXC_COMMON_BEGIN(machine_check_idle_common)
 	 * Then decrement MCE nesting after finishing with the stack.
 	 */
 	ld	r3,_MSR(r1)
+	ld	r4,_LINK(r1)
 
 	lhz	r11,PACA_IN_MCE(r13)
 	subi	r11,r11,1
 	sth	r11,PACA_IN_MCE(r13)
 
-	/* Turn off the RI bit because SRR1 is used by idle wakeup code. */
-	/* Recoverability could be improved by reducing the use of SRR1. */
-	li	r11,0
-	mtmsrd	r11,1
-
-	b	pnv_powersave_wakeup_mce
+	mtlr	r4
+	rlwinm	r10,r3,47-31,30,31
+	cmpwi	cr3,r10,2
+	bltlr	cr3	/* no state loss, return to idle caller */
+	b	idle_return_gpr_loss
 #endif
 	/*
 	 * Handle machine check early in real mode. We come here with
diff --git a/arch/powerpc/kernel/idle_book3s.S b/arch/powerpc/kernel/idle_book3s.S
index 7f5ac2e8581b..ffdee1ab4388 100644
--- a/arch/powerpc/kernel/idle_book3s.S
+++ b/arch/powerpc/kernel/idle_book3s.S
@@ -1,227 +1,87 @@
 /*
- *  This file contains idle entry/exit functions for POWER7,
- *  POWER8 and POWER9 CPUs.
+ *  Copyright 2018, IBM Corporation.
  *
  *  This program is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU General Public License
  *  as published by the Free Software Foundation; either version
  *  2 of the License, or (at your option) any later version.
+ *
+ *  This file contains general idle entry/exit functions to save
+ *  and restore stack and NVGPRs which allows C code to call idle
+ *  states that lose GPRs, and it will return transparently with
+ *  SRR1 wakeup reason return value.
+ *
+ *  The platform / CPU caller must ensure SPRs and any other non-GPR
+ *  state is saved and restored correctly, handle KVM, interrupts, etc.
  */
 
-#include <linux/threads.h>
-#include <asm/processor.h>
-#include <asm/page.h>
-#include <asm/cputable.h>
-#include <asm/thread_info.h>
 #include <asm/ppc_asm.h>
 #include <asm/asm-offsets.h>
 #include <asm/ppc-opcode.h>
-#include <asm/hw_irq.h>
-#include <asm/kvm_book3s_asm.h>
-#include <asm/opal.h>
 #include <asm/cpuidle.h>
-#include <asm/exception-64s.h>
-#include <asm/book3s/64/mmu-hash.h>
-#include <asm/mmu.h>
-#include <asm/asm-compat.h>
-#include <asm/feature-fixups.h>
-
-#undef DEBUG
 
 /*
- * Use unused space in the interrupt stack to save and restore
- * registers for winkle support.
- */
-#define _MMCR0	GPR0
-#define _SDR1	GPR3
-#define _PTCR	GPR3
-#define _RPR	GPR4
-#define _SPURR	GPR5
-#define _PURR	GPR6
-#define _TSCR	GPR7
-#define _DSCR	GPR8
-#define _AMOR	GPR9
-#define _WORT	GPR10
-#define _WORC	GPR11
-#define _LPCR	GPR12
-
-#define PSSCR_EC_ESL_MASK_SHIFTED          (PSSCR_EC | PSSCR_ESL) >> 16
-
-	.text
-
-/*
- * Used by threads before entering deep idle states. Saves SPRs
- * in interrupt stack frame
- */
-save_sprs_to_stack:
-	/*
-	 * Note all register i.e per-core, per-subcore or per-thread is saved
-	 * here since any thread in the core might wake up first
-	 */
-BEGIN_FTR_SECTION
-	/*
-	 * Note - SDR1 is dropped in Power ISA v3. Hence not restoring
-	 * SDR1 here
-	 */
-	mfspr	r3,SPRN_PTCR
-	std	r3,_PTCR(r1)
-	mfspr	r3,SPRN_LPCR
-	std	r3,_LPCR(r1)
-FTR_SECTION_ELSE
-	mfspr	r3,SPRN_SDR1
-	std	r3,_SDR1(r1)
-ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
-	mfspr	r3,SPRN_RPR
-	std	r3,_RPR(r1)
-	mfspr	r3,SPRN_SPURR
-	std	r3,_SPURR(r1)
-	mfspr	r3,SPRN_PURR
-	std	r3,_PURR(r1)
-	mfspr	r3,SPRN_TSCR
-	std	r3,_TSCR(r1)
-	mfspr	r3,SPRN_DSCR
-	std	r3,_DSCR(r1)
-	mfspr	r3,SPRN_AMOR
-	std	r3,_AMOR(r1)
-	mfspr	r3,SPRN_WORT
-	std	r3,_WORT(r1)
-	mfspr	r3,SPRN_WORC
-	std	r3,_WORC(r1)
-/*
- * On POWER9, there are idle states such as stop4, invoked via cpuidle,
- * that lose hypervisor resources. In such cases, we need to save
- * additional SPRs before entering those idle states so that they can
- * be restored to their older values on wakeup from the idle state.
+ * Desired PSSCR in r3
+ *
+ * No state will be lost regardless of wakeup mechanism (interrupt or NIA).
  *
- * On POWER8, the only such deep idle state is winkle which is used
- * only in the context of CPU-Hotplug, where these additional SPRs are
- * reinitiazed to a sane value. Hence there is no need to save/restore
- * these SPRs.
+ * An EC=0 type wakeup will return with a value of 0. SRESET wakeup (which can
+ * happen with xscom SRESET and possibly MCE) may clobber volatiles except LR,
+ * and must blr, to return to caller with r3 set according to caller's expected
+ * return code (for Book3S/64 that is SRR1).
  */
-BEGIN_FTR_SECTION
-	blr
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
-
-power9_save_additional_sprs:
-	mfspr	r3, SPRN_PID
-	mfspr	r4, SPRN_LDBAR
-	std	r3, STOP_PID(r13)
-	std	r4, STOP_LDBAR(r13)
-
-	mfspr	r3, SPRN_FSCR
-	mfspr	r4, SPRN_HFSCR
-	std	r3, STOP_FSCR(r13)
-	std	r4, STOP_HFSCR(r13)
-
-	mfspr	r3, SPRN_MMCRA
-	mfspr	r4, SPRN_MMCR0
-	std	r3, STOP_MMCRA(r13)
-	std	r4, _MMCR0(r1)
-
-	mfspr	r3, SPRN_MMCR1
-	mfspr	r4, SPRN_MMCR2
-	std	r3, STOP_MMCR1(r13)
-	std	r4, STOP_MMCR2(r13)
-	blr
-
-power9_restore_additional_sprs:
-	ld	r3,_LPCR(r1)
-	ld	r4, STOP_PID(r13)
-	mtspr	SPRN_LPCR,r3
-	mtspr	SPRN_PID, r4
-
-	ld	r3, STOP_LDBAR(r13)
-	ld	r4, STOP_FSCR(r13)
-	mtspr	SPRN_LDBAR, r3
-	mtspr	SPRN_FSCR, r4
-
-	ld	r3, STOP_HFSCR(r13)
-	ld	r4, STOP_MMCRA(r13)
-	mtspr	SPRN_HFSCR, r3
-	mtspr	SPRN_MMCRA, r4
-
-	ld	r3, _MMCR0(r1)
-	ld	r4, STOP_MMCR1(r13)
-	mtspr	SPRN_MMCR0, r3
-	mtspr	SPRN_MMCR1, r4
-
-	ld	r3, STOP_MMCR2(r13)
-	ld	r4, PACA_SPRG_VDSO(r13)
-	mtspr	SPRN_MMCR2, r3
-	mtspr	SPRN_SPRG3, r4
+_GLOBAL(isa300_idle_stop_noloss)
+	mtspr 	SPRN_PSSCR,r3
+	PPC_STOP
+	li	r3,0
 	blr
 
 /*
- * Used by threads when the lock bit of core_idle_state is set.
- * Threads will spin in HMT_LOW until the lock bit is cleared.
- * r14 - pointer to core_idle_state
- * r15 - used to load contents of core_idle_state
- * r9  - used as a temporary variable
+ * Desired PSSCR in r3
+ *
+ * GPRs may be lost, so they are saved here. Wakeup is by interrupt only.
+ * The SRESET wakeup returns to this function's caller by calling
+ * idle_return_gpr_loss with r3 set to desired return value.
+ *
+ * A wakeup without GPR loss may alteratively be handled as in
+ * isa300_idle_stop_noloss and blr directly, as an optimisation.
+ *
+ * The caller is responsible for saving/restoring SPRs, MSR, timebase,
+ * etc.
  */
-
-core_idle_lock_held:
-	HMT_LOW
-3:	lwz	r15,0(r14)
-	andis.	r15,r15,PNV_CORE_IDLE_LOCK_BIT@h
-	bne	3b
-	HMT_MEDIUM
-	lwarx	r15,0,r14
-	andis.	r9,r15,PNV_CORE_IDLE_LOCK_BIT@h
-	bne-	core_idle_lock_held
-	blr
+_GLOBAL(isa300_idle_stop_mayloss)
+	mtspr 	SPRN_PSSCR,r3
+	std	r1,PACAR1(r13)
+	mflr	r4
+	mfcr	r5
+	/* use stack red zone rather than a new frame */
+	addi	r6,r1,-INT_FRAME_SIZE
+	SAVE_GPR(2, r6)
+	SAVE_NVGPRS(r6)
+	std	r4,_LINK(r6)
+	std	r5,_CCR(r6)
+	PPC_STOP
+	b	.	/* catch bugs */
 
 /*
- * Pass requested state in r3:
- *	r3 - PNV_THREAD_NAP/SLEEP/WINKLE in POWER8
- *	   - Requested PSSCR value in POWER9
+ * Desired return value in r3
  *
- * Address of idle handler to branch to in realmode in r4
+ * The idle wakeup SRESET interrupt can call this after calling
+ * to return to the idle sleep function caller with r3 as the return code.
+ *
+ * This must not be used if idle was entered via a _noloss function (use
+ * a simple blr instead).
  */
-pnv_powersave_common:
-	/* Use r3 to pass state nap/sleep/winkle */
-	/* NAP is a state loss, we create a regs frame on the
-	 * stack, fill it up with the state we care about and
-	 * stick a pointer to it in PACAR1. We really only
-	 * need to save PC, some CR bits and the NV GPRs,
-	 * but for now an interrupt frame will do.
-	 */
-	mtctr	r4
-
-	mflr	r0
-	std	r0,16(r1)
-	stdu	r1,-INT_FRAME_SIZE(r1)
-	std	r0,_LINK(r1)
-	std	r0,_NIP(r1)
-
-	/* We haven't lost state ... yet */
-	li	r0,0
-	stb	r0,PACA_NAPSTATELOST(r13)
-
-	/* Continue saving state */
-	SAVE_GPR(2, r1)
-	SAVE_NVGPRS(r1)
-	mfcr	r5
-	std	r5,_CCR(r1)
-	std	r1,PACAR1(r13)
-
-BEGIN_FTR_SECTION
-	/*
-	 * POWER9 does not require real mode to stop, and presently does not
-	 * set hwthread_state for KVM (threads don't share MMU context), so
-	 * we can remain in virtual mode for this.
-	 */
-	bctr
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-	/*
-	 * POWER8
-	 * Go to real mode to do the nap, as required by the architecture.
-	 * Also, we need to be in real mode before setting hwthread_state,
-	 * because as soon as we do that, another thread can switch
-	 * the MMU context to the guest.
-	 */
-	LOAD_REG_IMMEDIATE(r7, MSR_IDLE)
-	mtmsrd	r7,0
-	bctr
+_GLOBAL(idle_return_gpr_loss)
+	ld	r1,PACAR1(r13)
+	addi	r6,r1,-INT_FRAME_SIZE
+	ld	r4,_LINK(r6)
+	ld	r5,_CCR(r6)
+	REST_NVGPRS(r6)
+	REST_GPR(2, r6)
+	mtlr	r4
+	mtcr	r5
+	blr
 
 /*
  * This is the sequence required to execute idle instructions, as
@@ -234,723 +94,57 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
 	ld	r0,0(r1);					\
 236:	cmpd	cr0,r0,r0;					\
 	bne	236b;						\
-	IDLE_INST;
-
-
-	.globl pnv_enter_arch207_idle_mode
-pnv_enter_arch207_idle_mode:
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	/* Tell KVM we're entering idle */
-	li	r4,KVM_HWTHREAD_IN_IDLE
-	/******************************************************/
-	/*  N O T E   W E L L    ! ! !    N O T E   W E L L   */
-	/* The following store to HSTATE_HWTHREAD_STATE(r13)  */
-	/* MUST occur in real mode, i.e. with the MMU off,    */
-	/* and the MMU must stay off until we clear this flag */
-	/* and test HSTATE_HWTHREAD_REQ(r13) in               */
-	/* pnv_powersave_wakeup in this file.                 */
-	/* The reason is that another thread can switch the   */
-	/* MMU to a guest context whenever this flag is set   */
-	/* to KVM_HWTHREAD_IN_IDLE, and if the MMU was on,    */
-	/* that would potentially cause this thread to start  */
-	/* executing instructions from guest memory in        */
-	/* hypervisor mode, leading to a host crash or data   */
-	/* corruption, or worse.                              */
-	/******************************************************/
-	stb	r4,HSTATE_HWTHREAD_STATE(r13)
-#endif
-	stb	r3,PACA_THREAD_IDLE_STATE(r13)
-	cmpwi	cr3,r3,PNV_THREAD_SLEEP
-	bge	cr3,2f
-	IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP)
-	/* No return */
-2:
-	/* Sleep or winkle */
-	lbz	r7,PACA_THREAD_MASK(r13)
-	ld	r14,PACA_CORE_IDLE_STATE_PTR(r13)
-	li	r5,0
-	beq	cr3,3f
-	lis	r5,PNV_CORE_IDLE_WINKLE_COUNT@h
-3:
-lwarx_loop1:
-	lwarx	r15,0,r14
-
-	andis.	r9,r15,PNV_CORE_IDLE_LOCK_BIT@h
-	bnel-	core_idle_lock_held
-
-	add	r15,r15,r5			/* Add if winkle */
-	andc	r15,r15,r7			/* Clear thread bit */
-
-	andi.	r9,r15,PNV_CORE_IDLE_THREAD_BITS
-
-/*
- * If cr0 = 0, then current thread is the last thread of the core entering
- * sleep. Last thread needs to execute the hardware bug workaround code if
- * required by the platform.
- * Make the workaround call unconditionally here. The below branch call is
- * patched out when the idle states are discovered if the platform does not
- * require it.
- */
-.global pnv_fastsleep_workaround_at_entry
-pnv_fastsleep_workaround_at_entry:
-	beq	fastsleep_workaround_at_entry
-
-	stwcx.	r15,0,r14
-	bne-	lwarx_loop1
-	isync
-
-common_enter: /* common code for all the threads entering sleep or winkle */
-	bgt	cr3,enter_winkle
-	IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP)
-
-fastsleep_workaround_at_entry:
-	oris	r15,r15,PNV_CORE_IDLE_LOCK_BIT@h
-	stwcx.	r15,0,r14
-	bne-	lwarx_loop1
-	isync
-
-	/* Fast sleep workaround */
-	li	r3,1
-	li	r4,1
-	bl	opal_config_cpu_idle_state
-
-	/* Unlock */
-	xoris	r15,r15,PNV_CORE_IDLE_LOCK_BIT@h
-	lwsync
-	stw	r15,0(r14)
-	b	common_enter
-
-enter_winkle:
-	bl	save_sprs_to_stack
-
-	IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE)
-
-/*
- * r3 - PSSCR value corresponding to the requested stop state.
- */
-power_enter_stop:
-/*
- * Check if we are executing the lite variant with ESL=EC=0
- */
-	andis.   r4,r3,PSSCR_EC_ESL_MASK_SHIFTED
-	clrldi   r3,r3,60 /* r3 = Bits[60:63] = Requested Level (RL) */
-	bne	 .Lhandle_esl_ec_set
-	PPC_STOP
-	li	r3,0  /* Since we didn't lose state, return 0 */
-	std	r3, PACA_REQ_PSSCR(r13)
-
-	/*
-	 * pnv_wakeup_noloss() expects r12 to contain the SRR1 value so
-	 * it can determine if the wakeup reason is an HMI in
-	 * CHECK_HMI_INTERRUPT.
-	 *
-	 * However, when we wakeup with ESL=0, SRR1 will not contain the wakeup
-	 * reason, so there is no point setting r12 to SRR1.
-	 *
-	 * Further, we clear r12 here, so that we don't accidentally enter the
-	 * HMI in pnv_wakeup_noloss() if the value of r12[42:45] == WAKE_HMI.
-	 */
-	li	r12, 0
-	b 	pnv_wakeup_noloss
-
-.Lhandle_esl_ec_set:
-BEGIN_FTR_SECTION
-	/*
-	 * POWER9 DD2.0 or earlier can incorrectly set PMAO when waking up after
-	 * a state-loss idle. Saving and restoring MMCR0 over idle is a
-	 * workaround.
-	 */
-	mfspr	r4,SPRN_MMCR0
-	std	r4,_MMCR0(r1)
-END_FTR_SECTION_IFCLR(CPU_FTR_POWER9_DD2_1)
-
-/*
- * Check if the requested state is a deep idle state.
- */
-	LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state)
-	ld	r4,ADDROFF(pnv_first_deep_stop_state)(r5)
-	cmpd	r3,r4
-	bge	.Lhandle_deep_stop
-	PPC_STOP	/* Does not return (system reset interrupt) */
-
-.Lhandle_deep_stop:
-/*
- * Entering deep idle state.
- * Clear thread bit in PACA_CORE_IDLE_STATE, save SPRs to
- * stack and enter stop
- */
-	lbz     r7,PACA_THREAD_MASK(r13)
-	ld      r14,PACA_CORE_IDLE_STATE_PTR(r13)
-
-lwarx_loop_stop:
-	lwarx   r15,0,r14
-	andis.	r9,r15,PNV_CORE_IDLE_LOCK_BIT@h
-	bnel-	core_idle_lock_held
-	andc    r15,r15,r7                      /* Clear thread bit */
-
-	stwcx.  r15,0,r14
-	bne-    lwarx_loop_stop
-	isync
-
-	bl	save_sprs_to_stack
-
-	PPC_STOP	/* Does not return (system reset interrupt) */
-
-/*
- * Entered with MSR[EE]=0 and no soft-masked interrupts pending.
- * r3 contains desired idle state (PNV_THREAD_NAP/SLEEP/WINKLE).
- */
-_GLOBAL(power7_idle_insn)
-	/* Now check if user or arch enabled NAP mode */
-	LOAD_REG_ADDR(r4, pnv_enter_arch207_idle_mode)
-	b	pnv_powersave_common
-
-#define CHECK_HMI_INTERRUPT						\
-BEGIN_FTR_SECTION_NESTED(66);						\
-	rlwinm	r0,r12,45-31,0xf;  /* extract wake reason field (P8) */	\
-FTR_SECTION_ELSE_NESTED(66);						\
-	rlwinm	r0,r12,45-31,0xe;  /* P7 wake reason field is 3 bits */	\
-ALT_FTR_SECTION_END_NESTED_IFSET(CPU_FTR_ARCH_207S, 66);		\
-	cmpwi	r0,0xa;			/* Hypervisor maintenance ? */	\
-	bne+	20f;							\
-	/* Invoke opal call to handle hmi */				\
-	ld	r2,PACATOC(r13);					\
-	ld	r1,PACAR1(r13);						\
-	std	r3,ORIG_GPR3(r1);	/* Save original r3 */		\
-	li	r3,0;			/* NULL argument */		\
-	bl	hmi_exception_realmode;					\
-	nop;								\
-	ld	r3,ORIG_GPR3(r1);	/* Restore original r3 */	\
-20:	nop;
-
-/*
- * Entered with MSR[EE]=0 and no soft-masked interrupts pending.
- * r3 contains desired PSSCR register value.
- *
- * Offline (CPU unplug) case also must notify KVM that the CPU is
- * idle.
- */
-_GLOBAL(power9_offline_stop)
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	/*
-	 * Tell KVM we're entering idle.
-	 * This does not have to be done in real mode because the P9 MMU
-	 * is independent per-thread. Some steppings share radix/hash mode
-	 * between threads, but in that case KVM has a barrier sync in real
-	 * mode before and after switching between radix and hash.
-	 */
-	li	r4,KVM_HWTHREAD_IN_IDLE
-	stb	r4,HSTATE_HWTHREAD_STATE(r13)
-#endif
-	/* fall through */
-
-_GLOBAL(power9_idle_stop)
-	std	r3, PACA_REQ_PSSCR(r13)
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-BEGIN_FTR_SECTION
-	sync
-	lwz	r5, PACA_DONT_STOP(r13)
-	cmpwi	r5, 0
-	bne	1f
-END_FTR_SECTION_IFSET(CPU_FTR_P9_TM_XER_SO_BUG)
-#endif
-	mtspr 	SPRN_PSSCR,r3
-	LOAD_REG_ADDR(r4,power_enter_stop)
-	b	pnv_powersave_common
-	/* No return */
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-1:
-	/*
-	 * We get here when TM / thread reconfiguration bug workaround
-	 * code wants to get the CPU into SMT4 mode, and therefore
-	 * we are being asked not to stop.
-	 */
-	li	r3, 0
-	std	r3, PACA_REQ_PSSCR(r13)
-	blr		/* return 0 for wakeup cause / SRR1 value */
-#endif
-
-/*
- * Called from machine check handler for powersave wakeups.
- * Low level machine check processing has already been done. Now just
- * go through the wake up path to get everything in order.
- *
- * r3 - The original SRR1 value.
- * Original SRR[01] have been clobbered.
- * MSR_RI is clear.
- */
-.global pnv_powersave_wakeup_mce
-pnv_powersave_wakeup_mce:
-	/* Set cr3 for pnv_powersave_wakeup */
-	rlwinm	r11,r3,47-31,30,31
-	cmpwi	cr3,r11,2
-
-	/*
-	 * Now put the original SRR1 with SRR1_WAKEMCE_RESVD as the wake
-	 * reason into r12, which allows reuse of the system reset wakeup
-	 * code without being mistaken for another type of wakeup.
-	 */
-	oris	r12,r3,SRR1_WAKEMCE_RESVD@h
-
-	b	pnv_powersave_wakeup
-
-/*
- * Called from reset vector for powersave wakeups.
- * cr3 - set to gt if waking up with partial/complete hypervisor state loss
- * r12 - SRR1
- */
-.global pnv_powersave_wakeup
-pnv_powersave_wakeup:
-	ld	r2, PACATOC(r13)
-
-BEGIN_FTR_SECTION
-	bl	pnv_restore_hyp_resource_arch300
-FTR_SECTION_ELSE
-	bl	pnv_restore_hyp_resource_arch207
-ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
-
-	li	r0,PNV_THREAD_RUNNING
-	stb	r0,PACA_THREAD_IDLE_STATE(r13)	/* Clear thread state */
-
-	mr	r3,r12
-
-#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
-	lbz	r0,HSTATE_HWTHREAD_STATE(r13)
-	cmpwi	r0,KVM_HWTHREAD_IN_KERNEL
-	beq	0f
-	li	r0,KVM_HWTHREAD_IN_KERNEL
-	stb	r0,HSTATE_HWTHREAD_STATE(r13)
-	/* Order setting hwthread_state vs. testing hwthread_req */
-	sync
-0:	lbz	r0,HSTATE_HWTHREAD_REQ(r13)
-	cmpwi	r0,0
-	beq	1f
-	b	kvm_start_guest
-1:
-#endif
-
-	/* Return SRR1 from power7_nap() */
-	blt	cr3,pnv_wakeup_noloss
-	b	pnv_wakeup_loss
+	IDLE_INST;						\
+	b	.	/* catch bugs */
 
 /*
- * Check whether we have woken up with hypervisor state loss.
- * If yes, restore hypervisor state and return back to link.
+ * Desired instruction type in r3
  *
- * cr3 - set to gt if waking up with partial/complete hypervisor state loss
- */
-pnv_restore_hyp_resource_arch300:
-	/*
-	 * Workaround for POWER9, if we lost resources, the ERAT
-	 * might have been mixed up and needs flushing. We also need
-	 * to reload MMCR0 (see comment above). We also need to set
-	 * then clear bit 60 in MMCRA to ensure the PMU starts running.
-	 */
-	blt	cr3,1f
-BEGIN_FTR_SECTION
-	PPC_INVALIDATE_ERAT
-	ld	r1,PACAR1(r13)
-	ld	r4,_MMCR0(r1)
-	mtspr	SPRN_MMCR0,r4
-END_FTR_SECTION_IFCLR(CPU_FTR_POWER9_DD2_1)
-	mfspr	r4,SPRN_MMCRA
-	ori	r4,r4,(1 << (63-60))
-	mtspr	SPRN_MMCRA,r4
-	xori	r4,r4,(1 << (63-60))
-	mtspr	SPRN_MMCRA,r4
-1:
-	/*
-	 * POWER ISA 3. Use PSSCR to determine if we
-	 * are waking up from deep idle state
-	 */
-	LOAD_REG_ADDRBASE(r5,pnv_first_deep_stop_state)
-	ld	r4,ADDROFF(pnv_first_deep_stop_state)(r5)
-
-	/*
-	 * 0-3 bits correspond to Power-Saving Level Status
-	 * which indicates the idle state we are waking up from
-	 */
-	mfspr	r5, SPRN_PSSCR
-	rldicl  r5,r5,4,60
-	li	r0, 0		/* clear requested_psscr to say we're awake */
-	std	r0, PACA_REQ_PSSCR(r13)
-	cmpd	cr4,r5,r4
-	bge	cr4,pnv_wakeup_tb_loss /* returns to caller */
-
-	blr	/* Waking up without hypervisor state loss. */
-
-/* Same calling convention as arch300 */
-pnv_restore_hyp_resource_arch207:
-	/*
-	 * POWER ISA 2.07 or less.
-	 * Check if we slept with sleep or winkle.
-	 */
-	lbz	r4,PACA_THREAD_IDLE_STATE(r13)
-	cmpwi	cr2,r4,PNV_THREAD_NAP
-	bgt	cr2,pnv_wakeup_tb_loss	/* Either sleep or Winkle */
-
-	/*
-	 * We fall through here if PACA_THREAD_IDLE_STATE shows we are waking
-	 * up from nap. At this stage CR3 shouldn't contains 'gt' since that
-	 * indicates we are waking with hypervisor state loss from nap.
-	 */
-	bgt	cr3,.
-
-	blr	/* Waking up without hypervisor state loss */
-
-/*
- * Called if waking up from idle state which can cause either partial or
- * complete hyp state loss.
- * In POWER8, called if waking up from fastsleep or winkle
- * In POWER9, called if waking up from stop state >= pnv_first_deep_stop_state
+ * GPRs may be lost, so they are saved here. Wakeup is by interrupt only.
+ * The SRESET wakeup returns to this function's caller by calling
+ * idle_return_gpr_loss with r3 set to desired return value.
  *
- * r13 - PACA
- * cr3 - gt if waking up with partial/complete hypervisor state loss
+ * A wakeup without GPR loss may alteratively be handled as in
+ * isa300_idle_stop_noloss and blr directly, as an optimisation.
  *
- * If ISA300:
- * cr4 - gt or eq if waking up from complete hypervisor state loss.
+ * The caller is responsible for saving/restoring SPRs, MSR, timebase,
+ * etc.
  *
- * If ISA207:
- * r4 - PACA_THREAD_IDLE_STATE
+ * This must be called in real-mode.
  */
-pnv_wakeup_tb_loss:
-	ld	r1,PACAR1(r13)
-	/*
-	 * Before entering any idle state, the NVGPRs are saved in the stack.
-	 * If there was a state loss, or PACA_NAPSTATELOST was set, then the
-	 * NVGPRs are restored. If we are here, it is likely that state is lost,
-	 * but not guaranteed -- neither ISA207 nor ISA300 tests to reach
-	 * here are the same as the test to restore NVGPRS:
-	 * PACA_THREAD_IDLE_STATE test for ISA207, PSSCR test for ISA300,
-	 * and SRR1 test for restoring NVGPRs.
-	 *
-	 * We are about to clobber NVGPRs now, so set NAPSTATELOST to
-	 * guarantee they will always be restored. This might be tightened
-	 * with careful reading of specs (particularly for ISA300) but this
-	 * is already a slow wakeup path and it's simpler to be safe.
-	 */
-	li	r0,1
-	stb	r0,PACA_NAPSTATELOST(r13)
-
-	/*
-	 *
-	 * Save SRR1 and LR in NVGPRs as they might be clobbered in
-	 * opal_call() (called in CHECK_HMI_INTERRUPT). SRR1 is required
-	 * to determine the wakeup reason if we branch to kvm_start_guest. LR
-	 * is required to return back to reset vector after hypervisor state
-	 * restore is complete.
-	 */
-	mr	r19,r12
-	mr	r18,r4
-	mflr	r17
-BEGIN_FTR_SECTION
-	CHECK_HMI_INTERRUPT
-END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
-
-	ld	r14,PACA_CORE_IDLE_STATE_PTR(r13)
-	lbz	r7,PACA_THREAD_MASK(r13)
-
-	/*
-	 * Take the core lock to synchronize against other threads.
-	 *
-	 * Lock bit is set in one of the 2 cases-
-	 * a. In the sleep/winkle enter path, the last thread is executing
-	 * fastsleep workaround code.
-	 * b. In the wake up path, another thread is executing fastsleep
-	 * workaround undo code or resyncing timebase or restoring context
-	 * In either case loop until the lock bit is cleared.
-	 */
-1:
-	lwarx	r15,0,r14
-	andis.	r9,r15,PNV_CORE_IDLE_LOCK_BIT@h
-	bnel-	core_idle_lock_held
-	oris	r15,r15,PNV_CORE_IDLE_LOCK_BIT@h
-	stwcx.	r15,0,r14
-	bne-	1b
-	isync
-
-	andi.	r9,r15,PNV_CORE_IDLE_THREAD_BITS
-	cmpwi	cr2,r9,0
-
-	/*
-	 * At this stage
-	 * cr2 - eq if first thread to wakeup in core
-	 * cr3-  gt if waking up with partial/complete hypervisor state loss
-	 * ISA300:
-	 * cr4 - gt or eq if waking up from complete hypervisor state loss.
-	 */
-
-BEGIN_FTR_SECTION
-	/*
-	 * Were we in winkle?
-	 * If yes, check if all threads were in winkle, decrement our
-	 * winkle count, set all thread winkle bits if all were in winkle.
-	 * Check if our thread has a winkle bit set, and set cr4 accordingly
-	 * (to match ISA300, above). Pseudo-code for core idle state
-	 * transitions for ISA207 is as follows (everything happens atomically
-	 * due to store conditional and/or lock bit):
-	 *
-	 * nap_idle() { }
-	 * nap_wake() { }
-	 *
-	 * sleep_idle()
-	 * {
-	 *	core_idle_state &= ~thread_in_core
-	 * }
-	 *
-	 * sleep_wake()
-	 * {
-	 *     bool first_in_core, first_in_subcore;
-	 *
-	 *     first_in_core = (core_idle_state & IDLE_THREAD_BITS) == 0;
-	 *     first_in_subcore = (core_idle_state & SUBCORE_SIBLING_MASK) == 0;
-	 *
-	 *     core_idle_state |= thread_in_core;
-	 * }
-	 *
-	 * winkle_idle()
-	 * {
-	 *	core_idle_state &= ~thread_in_core;
-	 *	core_idle_state += 1 << WINKLE_COUNT_SHIFT;
-	 * }
-	 *
-	 * winkle_wake()
-	 * {
-	 *     bool first_in_core, first_in_subcore, winkle_state_lost;
-	 *
-	 *     first_in_core = (core_idle_state & IDLE_THREAD_BITS) == 0;
-	 *     first_in_subcore = (core_idle_state & SUBCORE_SIBLING_MASK) == 0;
-	 *
-	 *     core_idle_state |= thread_in_core;
-	 *
-	 *     if ((core_idle_state & WINKLE_MASK) == (8 << WINKLE_COUNT_SIHFT))
-	 *         core_idle_state |= THREAD_WINKLE_BITS;
-	 *     core_idle_state -= 1 << WINKLE_COUNT_SHIFT;
-	 *
-	 *     winkle_state_lost = core_idle_state &
-	 *				(thread_in_core << WINKLE_THREAD_SHIFT);
-	 *     core_idle_state &= ~(thread_in_core << WINKLE_THREAD_SHIFT);
-	 * }
-	 *
-	 */
-	cmpwi	r18,PNV_THREAD_WINKLE
+_GLOBAL(isa206_idle_insn_mayloss)
+	std	r1,PACAR1(r13)
+	mflr	r4
+	mfcr	r5
+	/* use stack red zone rather than a new frame */
+	addi	r6,r1,-INT_FRAME_SIZE
+	SAVE_GPR(2, r6)
+	SAVE_NVGPRS(r6)
+	std	r4,_LINK(r6)
+	std	r5,_CCR(r6)
+	cmpwi	r3,PNV_THREAD_NAP
+	bne	1f
+	IDLE_STATE_ENTER_SEQ_NORET(PPC_NAP)
+1:	cmpwi	r3,PNV_THREAD_SLEEP
 	bne	2f
-	andis.	r9,r15,PNV_CORE_IDLE_WINKLE_COUNT_ALL_BIT@h
-	subis	r15,r15,PNV_CORE_IDLE_WINKLE_COUNT@h
-	beq	2f
-	ori	r15,r15,PNV_CORE_IDLE_THREAD_WINKLE_BITS /* all were winkle */
-2:
-	/* Shift thread bit to winkle mask, then test if this thread is set,
-	 * and remove it from the winkle bits */
-	slwi	r8,r7,8
-	and	r8,r8,r15
-	andc	r15,r15,r8
-	cmpwi	cr4,r8,1 /* cr4 will be gt if our bit is set, lt if not */
-
-	lbz	r4,PACA_SUBCORE_SIBLING_MASK(r13)
-	and	r4,r4,r15
-	cmpwi	r4,0	/* Check if first in subcore */
-
-	or	r15,r15,r7		/* Set thread bit */
-	beq	first_thread_in_subcore
-END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300)
-
-	or	r15,r15,r7		/* Set thread bit */
-	beq	cr2,first_thread_in_core
-
-	/* Not first thread in core or subcore to wake up */
-	b	clear_lock
-
-first_thread_in_subcore:
-	/*
-	 * If waking up from sleep, subcore state is not lost. Hence
-	 * skip subcore state restore
-	 */
-	blt	cr4,subcore_state_restored
-
-	/* Restore per-subcore state */
-	ld      r4,_SDR1(r1)
-	mtspr   SPRN_SDR1,r4
-
-	ld      r4,_RPR(r1)
-	mtspr   SPRN_RPR,r4
-	ld	r4,_AMOR(r1)
-	mtspr	SPRN_AMOR,r4
-
-subcore_state_restored:
-	/*
-	 * Check if the thread is also the first thread in the core. If not,
-	 * skip to clear_lock.
-	 */
-	bne	cr2,clear_lock
-
-first_thread_in_core:
-
-	/*
-	 * First thread in the core waking up from any state which can cause
-	 * partial or complete hypervisor state loss. It needs to
-	 * call the fastsleep workaround code if the platform requires it.
-	 * Call it unconditionally here. The below branch instruction will
-	 * be patched out if the platform does not have fastsleep or does not
-	 * require the workaround. Patching will be performed during the
-	 * discovery of idle-states.
-	 */
-.global pnv_fastsleep_workaround_at_exit
-pnv_fastsleep_workaround_at_exit:
-	b	fastsleep_workaround_at_exit
-
-timebase_resync:
-	/*
-	 * Use cr3 which indicates that we are waking up with atleast partial
-	 * hypervisor state loss to determine if TIMEBASE RESYNC is needed.
-	 */
-	ble	cr3,.Ltb_resynced
-	/* Time base re-sync */
-	bl	opal_resync_timebase;
-	/*
-	 * If waking up from sleep (POWER8), per core state
-	 * is not lost, skip to clear_lock.
-	 */
-.Ltb_resynced:
-	blt	cr4,clear_lock
-
-	/*
-	 * First thread in the core to wake up and its waking up with
-	 * complete hypervisor state loss. Restore per core hypervisor
-	 * state.
-	 */
-BEGIN_FTR_SECTION
-	ld	r4,_PTCR(r1)
-	mtspr	SPRN_PTCR,r4
-	ld	r4,_RPR(r1)
-	mtspr	SPRN_RPR,r4
-	ld	r4,_AMOR(r1)
-	mtspr	SPRN_AMOR,r4
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-
-	ld	r4,_TSCR(r1)
-	mtspr	SPRN_TSCR,r4
-	ld	r4,_WORC(r1)
-	mtspr	SPRN_WORC,r4
-
-clear_lock:
-	xoris	r15,r15,PNV_CORE_IDLE_LOCK_BIT@h
-	lwsync
-	stw	r15,0(r14)
-
-common_exit:
-	/*
-	 * Common to all threads.
-	 *
-	 * If waking up from sleep, hypervisor state is not lost. Hence
-	 * skip hypervisor state restore.
-	 */
-	blt	cr4,hypervisor_state_restored
-
-	/* Waking up from winkle */
-
-BEGIN_MMU_FTR_SECTION
-	b	no_segments
-END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_RADIX)
-	/* Restore SLB  from PACA */
-	ld	r8,PACA_SLBSHADOWPTR(r13)
-
-	.rept	SLB_NUM_BOLTED
-	li	r3, SLBSHADOW_SAVEAREA
-	LDX_BE	r5, r8, r3
-	addi	r3, r3, 8
-	LDX_BE	r6, r8, r3
-	andis.	r7,r5,SLB_ESID_V@h
-	beq	1f
-	slbmte	r6,r5
-1:	addi	r8,r8,16
-	.endr
-no_segments:
-
-	/* Restore per thread state */
-
-	ld	r4,_SPURR(r1)
-	mtspr	SPRN_SPURR,r4
-	ld	r4,_PURR(r1)
-	mtspr	SPRN_PURR,r4
-	ld	r4,_DSCR(r1)
-	mtspr	SPRN_DSCR,r4
-	ld	r4,_WORT(r1)
-	mtspr	SPRN_WORT,r4
-
-	/* Call cur_cpu_spec->cpu_restore() */
-	LOAD_REG_ADDR(r4, cur_cpu_spec)
-	ld	r4,0(r4)
-	ld	r12,CPU_SPEC_RESTORE(r4)
-#ifdef PPC64_ELF_ABI_v1
-	ld	r12,0(r12)
-#endif
-	mtctr	r12
-	bctrl
-
-/*
- * On POWER9, we can come here on wakeup from a cpuidle stop state.
- * Hence restore the additional SPRs to the saved value.
- *
- * On POWER8, we come here only on winkle. Since winkle is used
- * only in the case of CPU-Hotplug, we don't need to restore
- * the additional SPRs.
- */
-BEGIN_FTR_SECTION
-	bl 	power9_restore_additional_sprs
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
-hypervisor_state_restored:
-
-	mr	r12,r19
-	mtlr	r17
-	blr		/* return to pnv_powersave_wakeup */
-
-fastsleep_workaround_at_exit:
-	li	r3,1
-	li	r4,0
-	bl	opal_config_cpu_idle_state
-	b	timebase_resync
-
-/*
- * R3 here contains the value that will be returned to the caller
- * of power7_nap.
- * R12 contains SRR1 for CHECK_HMI_INTERRUPT.
- */
-.global pnv_wakeup_loss
-pnv_wakeup_loss:
-	ld	r1,PACAR1(r13)
-BEGIN_FTR_SECTION
-	CHECK_HMI_INTERRUPT
-END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
-	REST_NVGPRS(r1)
-	REST_GPR(2, r1)
-	ld	r4,PACAKMSR(r13)
-	ld	r5,_LINK(r1)
-	ld	r6,_CCR(r1)
-	addi	r1,r1,INT_FRAME_SIZE
-	mtlr	r5
-	mtcr	r6
-	mtmsrd	r4
-	blr
+	IDLE_STATE_ENTER_SEQ_NORET(PPC_SLEEP)
+2:	IDLE_STATE_ENTER_SEQ_NORET(PPC_WINKLE)
 
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
 /*
- * R3 here contains the value that will be returned to the caller
- * of power7_nap.
- * R12 contains SRR1 for CHECK_HMI_INTERRUPT.
+ * This is used to branch into kvm_start_guest with non-volatiles saved.
+ * KVM should branch to idle_return_gpr_loss to return back out to the
+ * caller, with r3 as return code.
  */
-pnv_wakeup_noloss:
-	lbz	r0,PACA_NAPSTATELOST(r13)
-	cmpwi	r0,0
-	bne	pnv_wakeup_loss
-	ld	r1,PACAR1(r13)
-BEGIN_FTR_SECTION
-	CHECK_HMI_INTERRUPT
-END_FTR_SECTION_IFSET(CPU_FTR_HVMODE)
-	ld	r4,PACAKMSR(r13)
-	ld	r5,_NIP(r1)
-	ld	r6,_CCR(r1)
-	addi	r1,r1,INT_FRAME_SIZE
-	mtlr	r5
-	mtcr	r6
-	mtmsrd	r4
-	blr
+_GLOBAL(idle_kvm_start_guest)
+	std	r1,PACAR1(r13)
+	mflr	r4
+	mfcr	r5
+	/* use stack red zone rather than a new frame */
+	addi	r6,r1,-INT_FRAME_SIZE
+	SAVE_GPR(2, r6)
+	SAVE_NVGPRS(r6)
+	std	r4,_LINK(r6)
+	std	r5,_CCR(r6)
+	b	kvm_start_guest
+#endif
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 93fa0c99681e..6cb146823bfc 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -401,8 +401,8 @@ void __init check_for_initrd(void)
 
 #ifdef CONFIG_SMP
 
-int threads_per_core, threads_per_subcore, threads_shift;
-cpumask_t threads_core_mask;
+int threads_per_core, threads_per_subcore, threads_shift __read_mostly;
+cpumask_t threads_core_mask __read_mostly;
 EXPORT_SYMBOL_GPL(threads_per_core);
 EXPORT_SYMBOL_GPL(threads_per_subcore);
 EXPORT_SYMBOL_GPL(threads_shift);
diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
index 1d14046124a0..3da500e5f14f 100644
--- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S
@@ -34,6 +34,7 @@
 #include <asm/thread_info.h>
 #include <asm/asm-compat.h>
 #include <asm/feature-fixups.h>
+#include <asm/cpuidle.h>
 
 /* Sign-extend HDEC if not on POWER9 */
 #define EXTEND_HDEC(reg)			\
@@ -322,42 +323,27 @@ kvm_novcpu_exit:
 	b	kvmhv_switch_to_host
 
 /*
- * We come in here when wakened from nap mode.
- * Relocation is off and most register values are lost.
- * r13 points to the PACA.
+ * We come in here when wakened from Linux offline idle code.
+ * Relocation is off
  * r3 contains the SRR1 wakeup value, SRR1 is trashed.
  */
 	.globl	kvm_start_guest
 kvm_start_guest:
-	/* Set runlatch bit the minute you wake up from nap */
-	mfspr	r0, SPRN_CTRLF
-	ori 	r0, r0, 1
-	mtspr	SPRN_CTRLT, r0
-
 	/*
 	 * Could avoid this and pass it through in r3. For now,
 	 * code expects it to be in SRR1.
 	 */
 	mtspr	SPRN_SRR1,r3
 
-	ld	r2,PACATOC(r13)
-
 	li	r0,0
 	stb	r0,PACA_FTRACE_ENABLED(r13)
 
 	li	r0,KVM_HWTHREAD_IN_KVM
 	stb	r0,HSTATE_HWTHREAD_STATE(r13)
 
-	/* NV GPR values from power7_idle() will no longer be valid */
-	li	r0,1
-	stb	r0,PACA_NAPSTATELOST(r13)
-
-	/* were we napping due to cede? */
+	/* kvm cede / napping does not come through here */
 	lbz	r0,HSTATE_NAPPING(r13)
-	cmpwi	r0,NAPPING_CEDE
-	beq	kvm_end_cede
-	cmpwi	r0,NAPPING_NOVCPU
-	beq	kvm_novcpu_wakeup
+	twnei	r0,0
 
 	ld	r1,PACAEMERGSP(r13)
 	subi	r1,r1,STACK_FRAME_OVERHEAD
@@ -469,19 +455,17 @@ kvm_no_guest:
 	lbz	r3, HSTATE_HWTHREAD_REQ(r13)
 	cmpwi	r3, 0
 	bne	54f
-/*
- * We jump to pnv_wakeup_loss, which will return to the caller
- * of power7_nap in the powernv cpu offline loop.  The value we
- * put in r3 becomes the return value for power7_nap. pnv_wakeup_loss
- * requires SRR1 in r12.
- */
+
+	/*
+	 * Jump to idle_return_gpr_loss, which returns to the
+	 * idle_kvm_start_guest caller.
+	 */
 	li	r3, LPCR_PECE0
 	mfspr	r4, SPRN_LPCR
 	rlwimi	r4, r3, 0, LPCR_PECE0 | LPCR_PECE1
 	mtspr	SPRN_LPCR, r4
 	li	r3, 0
-	mfspr	r12,SPRN_SRR1
-	b	pnv_wakeup_loss
+	b	idle_return_gpr_loss
 
 53:	HMT_LOW
 	ld	r5, HSTATE_KVM_VCORE(r13)
@@ -2760,21 +2744,47 @@ BEGIN_FTR_SECTION
 	li	r4, LPCR_PECE_HVEE@higher
 	sldi	r4, r4, 32
 	or	r5, r5, r4
-END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
+FTR_SECTION_ELSE
+	li	r3, PNV_THREAD_NAP
+ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
 	mtspr	SPRN_LPCR,r5
 	isync
-	li	r0, 0
-	std	r0, HSTATE_SCRATCH0(r13)
-	ptesync
-	ld	r0, HSTATE_SCRATCH0(r13)
-1:	cmpd	r0, r0
-	bne	1b
+
+	mr	r0, r1
+	ld	r1, PACAEMERGSP(r13)
+	subi	r1, r1, STACK_FRAME_OVERHEAD
+	std	r0, 0(r1)
+	ld	r0, PACAR1(r13)
+	std	r0, 8(r1)
+
 BEGIN_FTR_SECTION
-	nap
+	bl	isa300_idle_stop_mayloss
 FTR_SECTION_ELSE
-	PPC_STOP
-ALT_FTR_SECTION_END_IFCLR(CPU_FTR_ARCH_300)
-	b	.
+	bl	isa206_idle_insn_mayloss
+ALT_FTR_SECTION_END_IFSET(CPU_FTR_ARCH_300)
+
+	mfspr	r0, SPRN_CTRLF
+	ori	r0, r0, 1
+	mtspr	SPRN_CTRLT, r0
+
+	ld	r0, 8(r1)
+	std	r0, PACAR1(r13)
+	ld	r1, 0(r1)
+
+	mtspr	SPRN_SRR1, r3
+
+	li	r0, 0
+	stb	r0, PACA_FTRACE_ENABLED(r13)
+
+	li	r0, KVM_HWTHREAD_IN_KVM
+	stb	r0, HSTATE_HWTHREAD_STATE(r13)
+
+	lbz	r0, HSTATE_NAPPING(r13)
+	cmpwi	r0, NAPPING_CEDE
+	beq	kvm_end_cede
+	cmpwi	r0, NAPPING_NOVCPU
+	beq	kvm_novcpu_wakeup
+	twi	31,0,0 /* Nap state must not be zero */
 
 33:	mr	r4, r3
 	li	r3, 0
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 35f699ebb662..09b754e08b51 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -16,6 +16,7 @@
 #include <linux/device.h>
 #include <linux/cpu.h>
 
+#include <asm/asm-prototypes.h>
 #include <asm/firmware.h>
 #include <asm/machdep.h>
 #include <asm/opal.h>
@@ -48,10 +49,10 @@ static u64 pnv_default_stop_mask;
 static bool default_stop_found;
 
 /*
- * First deep stop state. Used to figure out when to save/restore
- * hypervisor context.
+ * First stop state levels when HV and TB loss can occur.
  */
-u64 pnv_first_deep_stop_state = MAX_STOP_STATE;
+static u64 pnv_first_tb_loss_level = MAX_STOP_STATE + 1;
+static u64 pnv_first_hv_loss_level = MAX_STOP_STATE + 1;
 
 /*
  * psscr value and mask of the deepest stop idle state.
@@ -62,6 +63,8 @@ static u64 pnv_deepest_stop_psscr_mask;
 static u64 pnv_deepest_stop_flag;
 static bool deepest_stop_found;
 
+static unsigned long power7_offline_type;
+
 static int pnv_save_sprs_for_deep_states(void)
 {
 	int cpu;
@@ -72,12 +75,12 @@ static int pnv_save_sprs_for_deep_states(void)
 	 * all cpus at boot. Get these reg values of current cpu and use the
 	 * same across all cpus.
 	 */
-	uint64_t lpcr_val = mfspr(SPRN_LPCR);
-	uint64_t hid0_val = mfspr(SPRN_HID0);
-	uint64_t hid1_val = mfspr(SPRN_HID1);
-	uint64_t hid4_val = mfspr(SPRN_HID4);
-	uint64_t hid5_val = mfspr(SPRN_HID5);
-	uint64_t hmeer_val = mfspr(SPRN_HMEER);
+	uint64_t lpcr_val	= mfspr(SPRN_LPCR);
+	uint64_t hid0_val	= mfspr(SPRN_HID0);
+	uint64_t hid1_val	= mfspr(SPRN_HID1);
+	uint64_t hid4_val	= mfspr(SPRN_HID4);
+	uint64_t hid5_val	= mfspr(SPRN_HID5);
+	uint64_t hmeer_val	= mfspr(SPRN_HMEER);
 	uint64_t msr_val = MSR_IDLE;
 	uint64_t psscr_val = pnv_deepest_stop_psscr_val;
 
@@ -137,89 +140,6 @@ static int pnv_save_sprs_for_deep_states(void)
 	return 0;
 }
 
-static void pnv_alloc_idle_core_states(void)
-{
-	int i, j;
-	int nr_cores = cpu_nr_cores();
-	u32 *core_idle_state;
-
-	/*
-	 * core_idle_state - The lower 8 bits track the idle state of
-	 * each thread of the core.
-	 *
-	 * The most significant bit is the lock bit.
-	 *
-	 * Initially all the bits corresponding to threads_per_core
-	 * are set. They are cleared when the thread enters deep idle
-	 * state like sleep and winkle/stop.
-	 *
-	 * Initially the lock bit is cleared.  The lock bit has 2
-	 * purposes:
-	 * 	a. While the first thread in the core waking up from
-	 * 	   idle is restoring core state, it prevents other
-	 * 	   threads in the core from switching to process
-	 * 	   context.
-	 * 	b. While the last thread in the core is saving the
-	 *	   core state, it prevents a different thread from
-	 *	   waking up.
-	 */
-	for (i = 0; i < nr_cores; i++) {
-		int first_cpu = i * threads_per_core;
-		int node = cpu_to_node(first_cpu);
-		size_t paca_ptr_array_size;
-
-		core_idle_state = kmalloc_node(sizeof(u32), GFP_KERNEL, node);
-		*core_idle_state = (1 << threads_per_core) - 1;
-		paca_ptr_array_size = (threads_per_core *
-				       sizeof(struct paca_struct *));
-
-		for (j = 0; j < threads_per_core; j++) {
-			int cpu = first_cpu + j;
-
-			paca_ptrs[cpu]->core_idle_state_ptr = core_idle_state;
-			paca_ptrs[cpu]->thread_idle_state = PNV_THREAD_RUNNING;
-			paca_ptrs[cpu]->thread_mask = 1 << j;
-		}
-	}
-
-	update_subcore_sibling_mask();
-
-	if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT) {
-		int rc = pnv_save_sprs_for_deep_states();
-
-		if (likely(!rc))
-			return;
-
-		/*
-		 * The stop-api is unable to restore hypervisor
-		 * resources on wakeup from platform idle states which
-		 * lose full context. So disable such states.
-		 */
-		supported_cpuidle_states &= ~OPAL_PM_LOSE_FULL_CONTEXT;
-		pr_warn("cpuidle-powernv: Disabling idle states that lose full context\n");
-		pr_warn("cpuidle-powernv: Idle power-savings, CPU-Hotplug affected\n");
-
-		if (cpu_has_feature(CPU_FTR_ARCH_300) &&
-		    (pnv_deepest_stop_flag & OPAL_PM_LOSE_FULL_CONTEXT)) {
-			/*
-			 * Use the default stop state for CPU-Hotplug
-			 * if available.
-			 */
-			if (default_stop_found) {
-				pnv_deepest_stop_psscr_val =
-					pnv_default_stop_val;
-				pnv_deepest_stop_psscr_mask =
-					pnv_default_stop_mask;
-				pr_warn("cpuidle-powernv: Offlined CPUs will stop with psscr = 0x%016llx\n",
-					pnv_deepest_stop_psscr_val);
-			} else { /* Fallback to snooze loop for CPU-Hotplug */
-				deepest_stop_found = false;
-				pr_warn("cpuidle-powernv: Offlined CPUs will busy wait\n");
-			}
-		}
-	}
-}
-
 u32 pnv_get_supported_cpuidle_states(void)
 {
 	return supported_cpuidle_states;
@@ -238,6 +158,9 @@ static void pnv_fastsleep_workaround_apply(void *info)
 		*err = 1;
 }
 
+static bool power7_fastsleep_workaround_entry = true;
+static bool power7_fastsleep_workaround_exit = true;
+
 /*
  * Used to store fastsleep workaround state
  * 0 - Workaround applied/undone at fastsleep entry/exit path (Default)
@@ -277,13 +200,7 @@ static ssize_t store_fastsleep_workaround_applyonce(struct device *dev,
 	 * offlined, as last thread of the core entering fastsleep or deeper
 	 * state would have applied workaround.
 	 */
-	err = patch_instruction(
-		(unsigned int *)pnv_fastsleep_workaround_at_exit,
-		PPC_INST_NOP);
-	if (err) {
-		pr_err("fastsleep_workaround_applyonce change failed while patching pnv_fastsleep_workaround_at_exit");
-		goto fail;
-	}
+	power7_fastsleep_workaround_exit = false;
 
 	get_online_cpus();
 	primary_thread_mask = cpu_online_cores_map();
@@ -296,13 +213,7 @@ static ssize_t store_fastsleep_workaround_applyonce(struct device *dev,
 		goto fail;
 	}
 
-	err = patch_instruction(
-		(unsigned int *)pnv_fastsleep_workaround_at_entry,
-		PPC_INST_NOP);
-	if (err) {
-		pr_err("fastsleep_workaround_applyonce change failed while patching pnv_fastsleep_workaround_at_entry");
-		goto fail;
-	}
+	power7_fastsleep_workaround_entry = false;
 
 	fastsleep_workaround_applyonce = 1;
 
@@ -315,6 +226,308 @@ static DEVICE_ATTR(fastsleep_workaround_applyonce, 0600,
 			show_fastsleep_workaround_applyonce,
 			store_fastsleep_workaround_applyonce);
 
+static inline void atomic_start_thread_idle(void)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	int thread_nr = cpu_thread_in_core(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+
+	clear_bit(thread_nr, state);
+}
+
+static inline void atomic_stop_thread_idle(void)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	int thread_nr = cpu_thread_in_core(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+
+	set_bit(thread_nr, state);
+}
+
+static inline void atomic_lock_thread_idle(void)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+
+	while (unlikely(test_and_set_bit_lock(NR_PNV_CORE_IDLE_LOCK_BIT, state)))
+		barrier();
+}
+
+static inline void atomic_unlock_and_stop_thread_idle(void)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long thread = 1UL << cpu_thread_in_core(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+	u64 s = READ_ONCE(*state);
+	u64 new, tmp;
+
+	BUG_ON(!(s & PNV_CORE_IDLE_LOCK_BIT));
+	BUG_ON(s & thread);
+
+again:
+	new = (s | thread) & ~PNV_CORE_IDLE_LOCK_BIT;
+	tmp = cmpxchg(state, s, new);
+	if (unlikely(tmp != s)) {
+		s = tmp;
+		goto again;
+	}
+}
+
+static inline void atomic_unlock_thread_idle(void)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+
+	BUG_ON(!test_bit(NR_PNV_CORE_IDLE_LOCK_BIT, state));
+	clear_bit_unlock(NR_PNV_CORE_IDLE_LOCK_BIT, state);
+}
+
+/* P7 and P8 */
+struct p7_sprs {
+	/* per core */
+	u64 tscr;
+	u64 worc;
+
+	/* per subcore */
+	u64 sdr1;
+	u64 rpr;
+	u64 amor;
+
+	/* per thread */
+	u64 lpcr;
+	u64 hfscr;
+	u64 fscr;
+	u64 purr;
+	u64 spurr;
+	u64 dscr;
+	u64 wort;
+};
+
+static unsigned long power7_idle_insn(unsigned long type)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long thread = 1UL << cpu_thread_in_core(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+	unsigned long srr1;
+	bool full_winkle;
+	struct p7_sprs sprs;
+	bool sprs_saved = false;
+	int rc;
+
+	memset(&sprs, 0, sizeof(sprs));
+
+	if (unlikely(type != PNV_THREAD_NAP)) {
+		atomic_lock_thread_idle();
+
+		BUG_ON(!(*state & thread));
+		*state &= ~thread;
+
+		if (power7_fastsleep_workaround_entry) {
+			if ((*state & ((1 << threads_per_core) - 1)) == 0) {
+				rc = opal_config_cpu_idle_state(
+						OPAL_CONFIG_IDLE_FASTSLEEP,
+						OPAL_CONFIG_IDLE_APPLY);
+				BUG_ON(rc);
+			}
+		}
+
+		if (type == PNV_THREAD_WINKLE) {
+			sprs.tscr	= mfspr(SPRN_TSCR);
+			sprs.worc	= mfspr(SPRN_WORC);
+
+			sprs.sdr1	= mfspr(SPRN_SDR1);
+			sprs.rpr	= mfspr(SPRN_RPR);
+			sprs.amor	= mfspr(SPRN_AMOR);
+
+			sprs.lpcr	= mfspr(SPRN_LPCR);
+			if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+				sprs.hfscr	= mfspr(SPRN_HFSCR);
+				sprs.fscr	= mfspr(SPRN_FSCR);
+			}
+			sprs.purr	= mfspr(SPRN_PURR);
+			sprs.spurr	= mfspr(SPRN_SPURR);
+			sprs.dscr	= mfspr(SPRN_DSCR);
+			sprs.wort	= mfspr(SPRN_WORT);
+
+			sprs_saved = true;
+
+			/*
+			 * Increment winkle counter and set all winkle bits if
+			 * all threads are winkling. This allows wakeup side to
+			 * distinguish between fast sleep and winkle state
+			 * loss. Fast sleep still has to resync the timebase so
+			 * this may not be a really big win.
+			 */
+			*state += 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT;
+			if ((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) >> PNV_CORE_IDLE_WINKLE_COUNT_SHIFT == threads_per_core)
+				*state |= PNV_CORE_IDLE_THREAD_WINKLE_BITS;
+			WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) == 0);
+		}
+
+		atomic_unlock_thread_idle();
+	}
+
+	local_paca->thread_idle_state = type;
+	srr1 = isa206_idle_insn_mayloss(type);
+	local_paca->thread_idle_state = PNV_THREAD_RUNNING;
+
+	WARN_ON_ONCE(!srr1);
+	WARN_ON_ONCE(mfmsr() & (MSR_IR|MSR_DR));
+
+	if (unlikely((srr1 & SRR1_WAKEMASK_P8) == SRR1_WAKEHMI))
+		hmi_exception_realmode(NULL);
+
+	if (likely((srr1 & SRR1_WAKESTATE) != SRR1_WS_HVLOSS)) {
+		if (unlikely(type != PNV_THREAD_NAP)) {
+			atomic_lock_thread_idle();
+			if (type == PNV_THREAD_WINKLE) {
+				WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) == 0);
+				*state -= 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT;
+				*state &= ~(thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT);
+			}
+			atomic_unlock_and_stop_thread_idle();
+		}
+		return srr1;
+	}
+
+	/* HV state loss */
+	BUG_ON(type == PNV_THREAD_NAP);
+
+	atomic_lock_thread_idle();
+
+	full_winkle = false;
+	if (type == PNV_THREAD_WINKLE) {
+		WARN_ON((*state & PNV_CORE_IDLE_WINKLE_COUNT_BITS) == 0);
+		*state -= 1 << PNV_CORE_IDLE_WINKLE_COUNT_SHIFT;
+		if (*state & (thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT)) {
+			*state &= ~(thread << PNV_CORE_IDLE_THREAD_WINKLE_BITS_SHIFT);
+			full_winkle = true;
+			BUG_ON(!sprs_saved);
+		}
+	}
+
+	WARN_ON(*state & thread);
+
+	if ((*state & ((1 << threads_per_core) - 1)) != 0)
+		goto core_woken;
+
+	/* Per-core SPRs */
+	if (full_winkle) {
+		mtspr(SPRN_TSCR,	sprs.tscr);
+		mtspr(SPRN_WORC,	sprs.worc);
+	}
+
+	if (power7_fastsleep_workaround_exit) {
+		rc = opal_config_cpu_idle_state(OPAL_CONFIG_IDLE_FASTSLEEP,
+						OPAL_CONFIG_IDLE_UNDO);
+		BUG_ON(rc);
+	}
+
+	/* TB */
+	if (opal_resync_timebase() != OPAL_SUCCESS)
+		BUG();
+
+core_woken:
+	if (!full_winkle)
+		goto subcore_woken;
+
+	if ((*state & local_paca->subcore_sibling_mask) != 0)
+		goto subcore_woken;
+
+	/* Per-subcore SPRs */
+	mtspr(SPRN_SDR1,	sprs.sdr1);
+	mtspr(SPRN_RPR,		sprs.rpr);
+	mtspr(SPRN_AMOR,	sprs.amor);
+
+subcore_woken:
+	/*
+	 * isync after restoring shared SPRs and before unlocking. Unlock
+	 * only contains hwsync which does not necessarily do the right
+	 * thing for SPRs.
+	 */
+	isync();
+	atomic_unlock_and_stop_thread_idle();
+
+	/* Fast sleep does not lose SPRs */
+	if (!full_winkle)
+		return srr1;
+
+	/* Per-thread SPRs */
+	mtspr(SPRN_LPCR,	sprs.lpcr);
+	if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+		mtspr(SPRN_HFSCR,	sprs.hfscr);
+		mtspr(SPRN_FSCR,	sprs.fscr);
+	}
+	mtspr(SPRN_PURR,	sprs.purr);
+	mtspr(SPRN_SPURR,	sprs.spurr);
+	mtspr(SPRN_DSCR,	sprs.dscr);
+	mtspr(SPRN_WORT,	sprs.wort);
+
+	mtspr(SPRN_SPRG3,	local_paca->sprg_vdso);
+
+	/*
+	 * The SLB has to be restored here, but it sometimes still
+	 * contains entries, so the __ variant must be used to prevent
+	 * multi hits.
+	 */
+	__slb_restore_bolted_realmode();
+
+	return srr1;
+}
+
+extern unsigned long idle_kvm_start_guest(unsigned long srr1);
+
+#ifdef CONFIG_HOTPLUG_CPU
+static unsigned long power7_offline(void)
+{
+	unsigned long srr1;
+
+	mtmsr(MSR_IDLE);
+
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	/* Tell KVM we're entering idle. */
+	/******************************************************/
+	/*  N O T E   W E L L    ! ! !    N O T E   W E L L   */
+	/* The following store to HSTATE_HWTHREAD_STATE(r13)  */
+	/* MUST occur in real mode, i.e. with the MMU off,    */
+	/* and the MMU must stay off until we clear this flag */
+	/* and test HSTATE_HWTHREAD_REQ(r13) in               */
+	/* pnv_powersave_wakeup in this file.                 */
+	/* The reason is that another thread can switch the   */
+	/* MMU to a guest context whenever this flag is set   */
+	/* to KVM_HWTHREAD_IN_IDLE, and if the MMU was on,    */
+	/* that would potentially cause this thread to start  */
+	/* executing instructions from guest memory in        */
+	/* hypervisor mode, leading to a host crash or data   */
+	/* corruption, or worse.                              */
+	/******************************************************/
+	local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_IDLE;
+#endif
+
+	__ppc64_runlatch_off();
+	srr1 = power7_idle_insn(power7_offline_type);
+	__ppc64_runlatch_on();
+
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_KERNEL;
+	/* Order setting hwthread_state vs. testing hwthread_req */
+	smp_mb();
+	if (local_paca->kvm_hstate.hwthread_req)
+		srr1 = idle_kvm_start_guest(srr1);
+#endif
+
+	mtmsr(MSR_KERNEL);
+
+	return srr1;
+}
+#endif
+
 static unsigned long __power7_idle_type(unsigned long type)
 {
 	unsigned long srr1;
@@ -322,9 +535,11 @@ static unsigned long __power7_idle_type(unsigned long type)
 	if (!prep_irq_for_idle_irqsoff())
 		return 0;
 
+	mtmsr(MSR_IDLE);
 	__ppc64_runlatch_off();
 	srr1 = power7_idle_insn(type);
 	__ppc64_runlatch_on();
+	mtmsr(MSR_KERNEL);
 
 	fini_irq_for_idle_irqsoff();
 
@@ -347,6 +562,254 @@ void power7_idle(void)
 	power7_idle_type(PNV_THREAD_NAP);
 }
 
+struct p9_sprs {
+	/* per core */
+	u64 ptcr;
+	u64 rpr;
+	u64 tscr;
+	u64 ldbar;
+	u64 amor;
+
+	/* per thread */
+	u64 lpcr;
+	u64 hfscr;
+	u64 fscr;
+	u64 pid;
+	u64 purr;
+	u64 spurr;
+	u64 dscr;
+	u64 wort;
+
+	u64 mmcra;
+	u32 mmcr0;
+	u32 mmcr1;
+	u64 mmcr2;
+};
+
+static unsigned long power9_idle_stop(unsigned long psscr, bool mmu_on)
+{
+	int cpu = raw_smp_processor_id();
+	int first = cpu_first_thread_sibling(cpu);
+	unsigned long *state = &paca_ptrs[first]->idle_state;
+	unsigned long srr1;
+	unsigned long mmcr0 = 0;
+	struct p9_sprs sprs;
+	bool sprs_saved = false;
+
+	memset(&sprs, 0, sizeof(sprs));
+
+	if (!(psscr & (PSSCR_EC|PSSCR_ESL))) {
+		BUG_ON(!mmu_on);
+
+		/*
+		 * Wake synchronously. SRESET via xscom may still cause
+		 * a 0x100 powersave wakeup with SRR1 reason!
+		 */
+		srr1 = isa300_idle_stop_noloss(psscr);
+		if (likely(!srr1))
+			return 0;
+
+		/*
+		 * Registers not saved, can't recover!
+		 * This would be a hardware bug
+		 */
+		BUG_ON((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS);
+
+		goto out;
+	}
+
+	/* EC=ESL=1 case */
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	if (cpu_has_feature(CPU_FTR_P9_TM_XER_SO_BUG)) {
+		local_paca->requested_psscr = psscr;
+		/* order setting requested_psscr vs testing dont_stop */
+		smp_mb();
+		if (atomic_read(&local_paca->dont_stop)) {
+			local_paca->requested_psscr = 0;
+			return 0;
+		}
+	}
+#endif
+
+	if (!cpu_has_feature(CPU_FTR_POWER9_DD2_1)) {
+		 /*
+		  * POWER9 DD2 can incorrectly set PMAO when waking up
+		  * after a state-loss idle. Saving and restoring MMCR0
+		  * over idle is a workaround.
+		  */
+		mmcr0		= mfspr(SPRN_MMCR0);
+	}
+	if ((psscr & PSSCR_RL_MASK) >= pnv_first_hv_loss_level) {
+		sprs.lpcr	= mfspr(SPRN_LPCR);
+		sprs.hfscr	= mfspr(SPRN_HFSCR);
+		sprs.fscr	= mfspr(SPRN_FSCR);
+		sprs.pid	= mfspr(SPRN_PID);
+		sprs.purr	= mfspr(SPRN_PURR);
+		sprs.spurr	= mfspr(SPRN_SPURR);
+		sprs.dscr	= mfspr(SPRN_DSCR);
+		sprs.wort	= mfspr(SPRN_WORT);
+
+		sprs.mmcra	= mfspr(SPRN_MMCRA);
+		sprs.mmcr0	= mfspr(SPRN_MMCR0);
+		sprs.mmcr1	= mfspr(SPRN_MMCR1);
+		sprs.mmcr2	= mfspr(SPRN_MMCR2);
+
+		sprs.ptcr	= mfspr(SPRN_PTCR);
+		sprs.rpr	= mfspr(SPRN_RPR);
+		sprs.tscr	= mfspr(SPRN_TSCR);
+		sprs.ldbar	= mfspr(SPRN_LDBAR);
+		sprs.amor	= mfspr(SPRN_AMOR);
+
+		sprs_saved = true;
+
+		atomic_start_thread_idle();
+	}
+
+	srr1 = isa300_idle_stop_mayloss(psscr);
+
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	local_paca->requested_psscr = 0;
+#endif
+
+	psscr = mfspr(SPRN_PSSCR);
+
+	WARN_ON_ONCE(!srr1);
+	WARN_ON_ONCE(mfmsr() & (MSR_IR|MSR_DR));
+
+	if ((srr1 & SRR1_WAKESTATE) != SRR1_WS_NOLOSS) {
+		unsigned long mmcra;
+
+		/*
+		 * Workaround for POWER9 DD2.0, if we lost resources, the ERAT
+		 * might have been corrupted and needs flushing. We also need
+		 * to reload MMCR0 (see mmcr0 comment above).
+		 */
+		if (!cpu_has_feature(CPU_FTR_POWER9_DD2_1)) {
+			asm volatile(PPC_INVALIDATE_ERAT);
+			mtspr(SPRN_MMCR0, mmcr0);
+		}
+
+		/*
+		 * DD2.2 and earlier need to set then clear bit 60 in MMCRA
+		 * to ensure the PMU starts running.
+		 */
+		mmcra = mfspr(SPRN_MMCRA);
+		mmcra |= PPC_BIT(60);
+		mtspr(SPRN_MMCRA, mmcra);
+		mmcra &= ~PPC_BIT(60);
+		mtspr(SPRN_MMCRA, mmcra);
+	}
+
+	if (unlikely((srr1 & SRR1_WAKEMASK_P8) == SRR1_WAKEHMI))
+		hmi_exception_realmode(NULL);
+
+	/*
+	 * On POWER9, SRR1 bits do not match exactly as expected.
+	 * SRR1_WS_GPRLOSS (10b) can also result in SPR loss, so
+	 * always test PSSCR if there is any state loss.
+	 */
+	if (likely((psscr & PSSCR_RL_MASK) < pnv_first_hv_loss_level)) {
+		if (sprs_saved)
+			atomic_stop_thread_idle();
+		goto out;
+	}
+
+	/* HV state loss */
+	BUG_ON(!sprs_saved);
+
+	atomic_lock_thread_idle();
+
+	if ((*state & ((1 << threads_per_core) - 1)) != 0)
+		goto core_woken;
+
+	/* Per-core SPRs */
+	mtspr(SPRN_PTCR,	sprs.ptcr);
+	mtspr(SPRN_RPR,		sprs.rpr);
+	mtspr(SPRN_TSCR,	sprs.tscr);
+	mtspr(SPRN_LDBAR,	sprs.ldbar);
+	mtspr(SPRN_AMOR,	sprs.amor);
+
+	if ((psscr & PSSCR_RL_MASK) >= pnv_first_tb_loss_level) {
+		/* TB loss */
+		if (opal_resync_timebase() != OPAL_SUCCESS)
+			BUG();
+	}
+
+	/*
+	 * isync after restoring shared SPRs and before unlocking. Unlock
+	 * only contains hwsync which does not necessarily do the right
+	 * thing for SPRs.
+	 */
+	isync();
+
+core_woken:
+	atomic_unlock_and_stop_thread_idle();
+
+	/* Per-thread SPRs */
+	mtspr(SPRN_LPCR,	sprs.lpcr);
+	mtspr(SPRN_HFSCR,	sprs.hfscr);
+	mtspr(SPRN_FSCR,	sprs.fscr);
+	mtspr(SPRN_PID,		sprs.pid);
+	mtspr(SPRN_PURR,	sprs.purr);
+	mtspr(SPRN_SPURR,	sprs.spurr);
+	mtspr(SPRN_DSCR,	sprs.dscr);
+	mtspr(SPRN_WORT,	sprs.wort);
+
+	mtspr(SPRN_MMCRA,	sprs.mmcra);
+	mtspr(SPRN_MMCR0,	sprs.mmcr0);
+	mtspr(SPRN_MMCR1,	sprs.mmcr1);
+	mtspr(SPRN_MMCR2,	sprs.mmcr2);
+
+	mtspr(SPRN_SPRG3,	local_paca->sprg_vdso);
+
+	if (!radix_enabled())
+		__slb_restore_bolted_realmode();
+
+out:
+	if (mmu_on)
+		mtmsr(MSR_KERNEL);
+
+	return srr1;
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+static unsigned long power9_offline_stop(unsigned long psscr)
+{
+	unsigned long srr1;
+
+#ifndef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	__ppc64_runlatch_off();
+	srr1 = power9_idle_stop(psscr, true);
+	__ppc64_runlatch_on();
+#else
+	/*
+	 * Tell KVM we're entering idle.
+	 * This does not have to be done in real mode because the P9 MMU
+	 * is independent per-thread. Some steppings share radix/hash mode
+	 * between threads, but in that case KVM has a barrier sync in real
+	 * mode before and after switching between radix and hash.
+	 *
+	 * kvm_start_guest must still be called in real mode though, hence
+	 * the false argument.
+	 */
+	local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_IDLE;
+
+	__ppc64_runlatch_off();
+	srr1 = power9_idle_stop(psscr, false);
+	__ppc64_runlatch_on();
+
+	local_paca->kvm_hstate.hwthread_state = KVM_HWTHREAD_IN_KERNEL;
+	/* Order setting hwthread_state vs. testing hwthread_req */
+	smp_mb();
+	if (local_paca->kvm_hstate.hwthread_req)
+		srr1 = idle_kvm_start_guest(srr1);
+	mtmsr(MSR_KERNEL);
+#endif
+
+	return srr1;
+}
+#endif
+
 static unsigned long __power9_idle_type(unsigned long stop_psscr_val,
 				      unsigned long stop_psscr_mask)
 {
@@ -360,7 +823,7 @@ static unsigned long __power9_idle_type(unsigned long stop_psscr_val,
 	psscr = (psscr & ~stop_psscr_mask) | stop_psscr_val;
 
 	__ppc64_runlatch_off();
-	srr1 = power9_idle_stop(psscr);
+	srr1 = power9_idle_stop(psscr, true);
 	__ppc64_runlatch_on();
 
 	fini_irq_for_idle_irqsoff();
@@ -409,7 +872,7 @@ void pnv_power9_force_smt4_catch(void)
 			atomic_inc(&paca_ptrs[cpu0+thr]->dont_stop);
 	}
 	/* order setting dont_stop vs testing requested_psscr */
-	mb();
+	smp_mb();
 	for (thr = 0; thr < threads_per_core; ++thr) {
 		if (!paca_ptrs[cpu0+thr]->requested_psscr)
 			++awake_threads;
@@ -480,7 +943,6 @@ static void pnv_program_cpu_hotplug_lpcr(unsigned int cpu, u64 lpcr_val)
 unsigned long pnv_cpu_offline(unsigned int cpu)
 {
 	unsigned long srr1;
-	u32 idle_states = pnv_get_supported_cpuidle_states();
 	u64 lpcr_val;
 
 	/*
@@ -505,15 +967,8 @@ unsigned long pnv_cpu_offline(unsigned int cpu)
 		psscr = (psscr & ~pnv_deepest_stop_psscr_mask) |
 						pnv_deepest_stop_psscr_val;
 		srr1 = power9_offline_stop(psscr);
-
-	} else if ((idle_states & OPAL_PM_WINKLE_ENABLED) &&
-		   (idle_states & OPAL_PM_LOSE_FULL_CONTEXT)) {
-		srr1 = power7_idle_insn(PNV_THREAD_WINKLE);
-	} else if ((idle_states & OPAL_PM_SLEEP_ENABLED) ||
-		   (idle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
-		srr1 = power7_idle_insn(PNV_THREAD_SLEEP);
-	} else if (idle_states & OPAL_PM_NAP_ENABLED) {
-		srr1 = power7_idle_insn(PNV_THREAD_NAP);
+	} else if (cpu_has_feature(CPU_FTR_ARCH_206) && power7_offline_type) {
+		srr1 = power7_offline();
 	} else {
 		/* This is the fallback method. We emulate snooze */
 		while (!generic_check_cpu_restart(cpu)) {
@@ -619,33 +1074,32 @@ int validate_psscr_val_mask(u64 *psscr_val, u64 *psscr_mask, u32 flags)
  * @dt_idle_states: Number of idle state entries
  * Returns 0 on success
  */
-static int __init pnv_power9_idle_init(void)
+static void __init pnv_power9_idle_init(void)
 {
 	u64 max_residency_ns = 0;
 	int i;
 
 	/*
-	 * Set pnv_first_deep_stop_state, pnv_deepest_stop_psscr_{val,mask},
-	 * and the pnv_default_stop_{val,mask}.
-	 *
-	 * pnv_first_deep_stop_state should be set to the first stop
-	 * level to cause hypervisor state loss.
-	 *
 	 * pnv_deepest_stop_{val,mask} should be set to values corresponding to
 	 * the deepest stop state.
 	 *
 	 * pnv_default_stop_{val,mask} should be set to values corresponding to
-	 * the shallowest (OPAL_PM_STOP_INST_FAST) loss-less stop state.
+	 * the deepest loss-less (OPAL_PM_STOP_INST_FAST) stop state.
 	 */
-	pnv_first_deep_stop_state = MAX_STOP_STATE;
+	pnv_first_tb_loss_level = MAX_STOP_STATE + 1;
+	pnv_first_hv_loss_level = MAX_STOP_STATE + 1;
 	for (i = 0; i < nr_pnv_idle_states; i++) {
 		int err;
 		struct pnv_idle_states_t *state = &pnv_idle_states[i];
 		u64 psscr_rl = state->psscr_val & PSSCR_RL_MASK;
 
+		if ((state->flags & OPAL_PM_TIMEBASE_STOP) &&
+		     (pnv_first_tb_loss_level > psscr_rl))
+			pnv_first_tb_loss_level = psscr_rl;
+
 		if ((state->flags & OPAL_PM_LOSE_FULL_CONTEXT) &&
-		    pnv_first_deep_stop_state > psscr_rl)
-			pnv_first_deep_stop_state = psscr_rl;
+		     (pnv_first_hv_loss_level > psscr_rl))
+			pnv_first_hv_loss_level = psscr_rl;
 
 		err = validate_psscr_val_mask(&state->psscr_val,
 					      &state->psscr_mask,
@@ -670,6 +1124,7 @@ static int __init pnv_power9_idle_init(void)
 			pnv_default_stop_val = state->psscr_val;
 			pnv_default_stop_mask = state->psscr_mask;
 			default_stop_found = true;
+			WARN_ON(state->flags & OPAL_PM_LOSE_FULL_CONTEXT);
 		}
 	}
 
@@ -689,10 +1144,40 @@ static int __init pnv_power9_idle_init(void)
 			pnv_deepest_stop_psscr_mask);
 	}
 
-	pr_info("cpuidle-powernv: Requested Level (RL) value of first deep stop = 0x%llx\n",
-		pnv_first_deep_stop_state);
+	pr_info("cpuidle-powernv: First stop level that may lose SPRs = 0x%lld\n",
+		pnv_first_hv_loss_level);
 
-	return 0;
+	pr_info("cpuidle-powernv: First stop level that may lose timebase = 0x%lld\n",
+		pnv_first_tb_loss_level);
+}
+
+static void __init pnv_disable_deep_states(void)
+{
+	/*
+	 * The stop-api is unable to restore hypervisor
+	 * resources on wakeup from platform idle states which
+	 * lose full context. So disable such states.
+	 */
+	supported_cpuidle_states &= ~OPAL_PM_LOSE_FULL_CONTEXT;
+	pr_warn("cpuidle-powernv: Disabling idle states that lose full context\n");
+	pr_warn("cpuidle-powernv: Idle power-savings, CPU-Hotplug affected\n");
+
+	if (cpu_has_feature(CPU_FTR_ARCH_300) &&
+	    (pnv_deepest_stop_flag & OPAL_PM_LOSE_FULL_CONTEXT)) {
+		/*
+		 * Use the default stop state for CPU-Hotplug
+		 * if available.
+		 */
+		if (default_stop_found) {
+			pnv_deepest_stop_psscr_val = pnv_default_stop_val;
+			pnv_deepest_stop_psscr_mask = pnv_default_stop_mask;
+			pr_warn("cpuidle-powernv: Offlined CPUs will stop with psscr = 0x%016llx\n",
+				pnv_deepest_stop_psscr_val);
+		} else { /* Fallback to snooze loop for CPU-Hotplug */
+			deepest_stop_found = false;
+			pr_warn("cpuidle-powernv: Offlined CPUs will busy wait\n");
+		}
+	}
 }
 
 /*
@@ -707,10 +1192,8 @@ static void __init pnv_probe_idle_states(void)
 		return;
 	}
 
-	if (cpu_has_feature(CPU_FTR_ARCH_300)) {
-		if (pnv_power9_idle_init())
-			return;
-	}
+	if (cpu_has_feature(CPU_FTR_ARCH_300))
+		pnv_power9_idle_init();
 
 	for (i = 0; i < nr_pnv_idle_states; i++)
 		supported_cpuidle_states |= pnv_idle_states[i].flags;
@@ -830,11 +1313,33 @@ static int pnv_parse_cpuidle_dt(void)
 
 static int __init pnv_init_idle_states(void)
 {
+	int cpu;
 	int rc = 0;
-	supported_cpuidle_states = 0;
+
+	/* Set up PACA fields */
+	for_each_present_cpu(cpu) {
+		struct paca_struct *p = paca_ptrs[cpu];
+
+		p->idle_state = 0;
+		if (cpu == cpu_first_thread_sibling(cpu))
+			p->idle_state = (1 << threads_per_core) - 1;
+
+		if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+			/* P7/P8 nap */
+			p->thread_idle_state = PNV_THREAD_RUNNING;
+		} else {
+			/* P9 stop */
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+			p->requested_psscr = 0;
+			atomic_set(&p->dont_stop, 0);
+#endif
+		}
+	}
 
 	/* In case we error out nr_pnv_idle_states will be zero */
 	nr_pnv_idle_states = 0;
+	supported_cpuidle_states = 0;
+
 	if (cpuidle_disable != IDLE_NO_OVERRIDE)
 		goto out;
 	rc = pnv_parse_cpuidle_dt();
@@ -842,27 +1347,40 @@ static int __init pnv_init_idle_states(void)
 		return rc;
 	pnv_probe_idle_states();
 
-	if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
-		patch_instruction(
-			(unsigned int *)pnv_fastsleep_workaround_at_entry,
-			PPC_INST_NOP);
-		patch_instruction(
-			(unsigned int *)pnv_fastsleep_workaround_at_exit,
-			PPC_INST_NOP);
-	} else {
-		/*
-		 * OPAL_PM_SLEEP_ENABLED_ER1 is set. It indicates that
-		 * workaround is needed to use fastsleep. Provide sysfs
-		 * control to choose how this workaround has to be applied.
-		 */
-		device_create_file(cpu_subsys.dev_root,
+	if (!cpu_has_feature(CPU_FTR_ARCH_300)) {
+		if (!(supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
+			power7_fastsleep_workaround_entry = false;
+			power7_fastsleep_workaround_exit = false;
+		} else {
+			/*
+			 * OPAL_PM_SLEEP_ENABLED_ER1 is set. It indicates that
+			 * workaround is needed to use fastsleep. Provide sysfs
+			 * control to choose how this workaround has to be
+			 * applied.
+			 */
+			device_create_file(cpu_subsys.dev_root,
 				&dev_attr_fastsleep_workaround_applyonce);
-	}
+		}
+
+		update_subcore_sibling_mask();
 
-	pnv_alloc_idle_core_states();
+		if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED) {
+			ppc_md.power_save = power7_idle;
+			power7_offline_type = PNV_THREAD_NAP;
+		}
 
-	if (supported_cpuidle_states & OPAL_PM_NAP_ENABLED)
-		ppc_md.power_save = power7_idle;
+		if ((supported_cpuidle_states & OPAL_PM_WINKLE_ENABLED) &&
+			   (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT))
+			power7_offline_type = PNV_THREAD_WINKLE;
+		else if ((supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED) ||
+			   (supported_cpuidle_states & OPAL_PM_SLEEP_ENABLED_ER1))
+			power7_offline_type = PNV_THREAD_SLEEP;
+	}
+
+	if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT) {
+		if (pnv_save_sprs_for_deep_states())
+			pnv_disable_deep_states();
+	}
 
 out:
 	return 0;
diff --git a/arch/powerpc/platforms/powernv/subcore.c b/arch/powerpc/platforms/powernv/subcore.c
index 45563004feda..1d7a9fd30dd1 100644
--- a/arch/powerpc/platforms/powernv/subcore.c
+++ b/arch/powerpc/platforms/powernv/subcore.c
@@ -183,7 +183,7 @@ static void unsplit_core(void)
 	cpu = smp_processor_id();
 	if (cpu_thread_in_core(cpu) != 0) {
 		while (mfspr(SPRN_HID0) & mask)
-			power7_idle_insn(PNV_THREAD_NAP);
+			power7_idle_type(PNV_THREAD_NAP);
 
 		per_cpu(split_state, cpu).step = SYNC_STEP_UNSPLIT;
 		return;
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 4264aedc7775..129dcf7e3d9c 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2419,7 +2419,6 @@ static void dump_one_paca(int cpu)
 	DUMP(p, irq_happened, "%#-*x");
 	DUMP(p, io_sync, "%#-*x");
 	DUMP(p, irq_work_pending, "%#-*x");
-	DUMP(p, nap_state_lost, "%#-*x");
 	DUMP(p, sprg_vdso, "%#-*llx");
 
 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
@@ -2427,19 +2426,16 @@ static void dump_one_paca(int cpu)
 #endif
 
 #ifdef CONFIG_PPC_POWERNV
-	DUMP(p, core_idle_state_ptr, "%-*px");
-	DUMP(p, thread_idle_state, "%#-*x");
-	DUMP(p, thread_mask, "%#-*x");
-	DUMP(p, subcore_sibling_mask, "%#-*x");
-	DUMP(p, requested_psscr, "%#-*llx");
-	DUMP(p, stop_sprs.pid, "%#-*llx");
-	DUMP(p, stop_sprs.ldbar, "%#-*llx");
-	DUMP(p, stop_sprs.fscr, "%#-*llx");
-	DUMP(p, stop_sprs.hfscr, "%#-*llx");
-	DUMP(p, stop_sprs.mmcr1, "%#-*llx");
-	DUMP(p, stop_sprs.mmcr2, "%#-*llx");
-	DUMP(p, stop_sprs.mmcra, "%#-*llx");
-	DUMP(p, dont_stop.counter, "%#-*x");
+	DUMP(p, idle_state, "%#-*lx");
+	if (!early_cpu_has_feature(CPU_FTR_ARCH_300)) {
+		DUMP(p, thread_idle_state, "%#-*x");
+		DUMP(p, subcore_sibling_mask, "%#-*x");
+	} else {
+#ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+		DUMP(p, requested_psscr, "%#-*llx");
+		DUMP(p, dont_stop.counter, "%#-*x");
+#endif
+	}
 #endif
 
 	DUMP(p, accounting.utime, "%#-*lx");
-- 
2.18.0

^ permalink raw reply related

* Re: [PATCH 1/2] powerpc/boot: Fix crt0.S syntax for clang
From: Joel Stanley @ 2018-09-14  2:55 UTC (permalink / raw)
  To: Segher Boessenkool; +Cc: linuxppc-dev, Anton Blanchard
In-Reply-To: <20180911113228.GF23155@gate.crashing.org>

On Tue, 11 Sep 2018 at 21:02, Segher Boessenkool
<segher@kernel.crashing.org> wrote:
>
> On Mon, Sep 10, 2018 at 06:57:13PM +1000, Joel Stanley wrote:
> > Clang's assembler does not like the syntax of the cmpdi:
> >
> >  arch/powerpc/boot/crt0.S:168:22: error: unexpected modifier on variable reference
> >          cmpdi   12,RELACOUNT@l
> >                               ^
> >  arch/powerpc/boot/crt0.S:168:11: error: unknown operand
> >          cmpdi   12,RELACOUNT@l
> >                    ^
> > Enclosing RELACOUNT in () makes it is happy. Tested with GCC 8 and Clang
> > 8 (trunk).
>
> Is clang going to fix this?  You also might want to add a comment that
> this is a workaround for that broken assembler.

I am not sure that we need a comment, it doesn't look too out of place
compared to the other uses of wrapping symbols in ().

I did open a bug against clang though in the hope that they can fix
the behaviour:

 https://bugs.llvm.org/show_bug.cgi?id=38945

Cheers,

Joel

^ permalink raw reply

* Re: [PATCH] Correct PowerPC VDSO call frame info
From: Reza Arbab @ 2018-09-14  2:59 UTC (permalink / raw)
  To: Alan Modra; +Cc: linuxppc-dev, Michael Neuling
In-Reply-To: <20180913232704.GL3174@bubble.grove.modra.org>

On Fri, Sep 14, 2018 at 08:57:04AM +0930, Alan Modra wrote:
>There is control flow in __kernel_clock_gettime that reaches label 99
>without saving lr in r12.  CFI info however is interpreted by the
>unwinder without reference to control flow: It's a simple matter of
>"Execute all the CFI opcodes up to the current address".  That means
>the unwinder thinks r12 contains the return address at label 99.
>Disabuse it of that notion by resetting CFI for the return address at
>label 99.

Thanks for this! It looks like v2 will just be a commit log change, so 
feel free to carry over my

Tested-by: Reza Arbab <arbab@linux.ibm.com>

-- 
Reza Arbab

^ permalink raw reply

* [PATCH] PowerPC/VDSO: Correct call frame information
From: Alan Modra @ 2018-09-14  3:40 UTC (permalink / raw)
  To: Michael Neuling; +Cc: linuxppc-dev, Paul Mackerras, Michael Ellerman
In-Reply-To: <545f4cb2ca6f8d678798a387ea189bcf152842f9.camel@neuling.org>

Call Frame Information is used by gdb for back-traces and inserting
breakpoints on function return for the "finish" command.  This failed
when inside __kernel_clock_gettime.  More concerning than difficulty
debugging is that CFI is also used by stack frame unwinding code to
implement exceptions.  If you have an app that needs to handle
asynchronous exceptions for some reason, and you are unlucky enough to
get one inside the VDSO time functions, your app will crash.

What's wrong:  There is control flow in __kernel_clock_gettime that
reaches label 99 without saving lr in r12.  CFI info however is
interpreted by the unwinder without reference to control flow: It's a
simple matter of "Execute all the CFI opcodes up to the current
address".  That means the unwinder thinks r12 contains the return
address at label 99.  Disabuse it of that notion by resetting CFI for
the return address at label 99.

Note that the ".cfi_restore lr" could have gone anywhere from the
"mtlr r12" a few instructions earlier to the instruction at label 99.
I put the CFI as late as possible, because in general that's best
practice (and if possible grouped with other CFI in order to reduce
the number of CFI opcodes executed when unwinding).  Using r12 as the
return address is perfectly fine after the "mtlr r12" since r12 on
that code path still contains the return address.

__get_datapage also has a CFI error.  That function temporarily saves
lr in r0, and reflects that fact with ".cfi_register lr,r0".  A later
use of r0 means the CFI at that point isn't correct, as r0 no longer
contains the return address.  Fix that too.

Signed-off-by: Alan Modra <amodra@gmail.com>
Tested-by: Reza Arbab <arbab@linux.ibm.com>

diff --git a/arch/powerpc/kernel/vdso32/datapage.S b/arch/powerpc/kernel/vdso32/datapage.S
index 3745113fcc65..2a7eb5452aba 100644
--- a/arch/powerpc/kernel/vdso32/datapage.S
+++ b/arch/powerpc/kernel/vdso32/datapage.S
@@ -37,6 +37,7 @@ data_page_branch:
 	mtlr	r0
 	addi	r3, r3, __kernel_datapage_offset-data_page_branch
 	lwz	r0,0(r3)
+  .cfi_restore lr
 	add	r3,r0,r3
 	blr
   .cfi_endproc
diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
index 769c2624e0a6..1e0bc5955a40 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -139,6 +139,7 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
 	 */
 99:
 	li	r0,__NR_clock_gettime
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc
diff --git a/arch/powerpc/kernel/vdso64/datapage.S b/arch/powerpc/kernel/vdso64/datapage.S
index abf17feffe40..bf9668691511 100644
--- a/arch/powerpc/kernel/vdso64/datapage.S
+++ b/arch/powerpc/kernel/vdso64/datapage.S
@@ -37,6 +37,7 @@ data_page_branch:
 	mtlr	r0
 	addi	r3, r3, __kernel_datapage_offset-data_page_branch
 	lwz	r0,0(r3)
+  .cfi_restore lr
 	add	r3,r0,r3
 	blr
   .cfi_endproc
diff --git a/arch/powerpc/kernel/vdso64/gettimeofday.S b/arch/powerpc/kernel/vdso64/gettimeofday.S
index c002adcc694c..a4ed9edfd5f0 100644
--- a/arch/powerpc/kernel/vdso64/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso64/gettimeofday.S
@@ -169,6 +169,7 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
 	 */
 99:
 	li	r0,__NR_clock_gettime
+  .cfi_restore lr
 	sc
 	blr
   .cfi_endproc

-- 
Alan Modra
Australia Development Lab, IBM

^ permalink raw reply related

* [PATCH v2 0/5] powerpc: Clang build fixes
From: Joel Stanley @ 2018-09-14  4:06 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Anton Blanchard, Nick Desaulniers

v2 rolls up all of the fixes I have into the one series, and adds a few
more fixes.

With a one patch[1] on top of clang master I can build and boot a
powernv kernel. Note that we can't build altivec code using clang
yet[2], hence disabling MD_RAID456.

$ make ARCH=powerpc powernv_defconfig
$ ./scripts/config -d BTRFS_FS -d MD_RAID456
$ make CC=clang-8 CLANG_TRIPLE=powerpc64le-linux-gnu -j128

The build is very noisy as the ftrace recordmcount build step is not
picking up -Qunused-arguments.

$ qemu-system-ppc64 -M powernv -m 3G -nographic -kernel zImage.epapr \
 -L ~/skiboot/ -initrd ~/rootfs.cpio.xz

Linux version 4.19.0-rc3-00005-g7f51dcdecc6b (joel@ozrom3) (clang version 8.0.0 (trunk 342199)) #5 SMP Fri Sep 14 13:28:57 ACST 2018

I have discovered Nick D's clangBuiltLinux issue tracker[3] and will be
updating that as we find and fix issues.

[1] https://reviews.llvm.org/D50965
[2] https://bugs.llvm.org/show_bug.cgi?id=38887
[3] https://github.com/clangBuiltLinux/linux/issues

Anton Blanchard (2):
  powerpc/Makefiles: Fix clang/llvm build
  powerpc: Fix duplicate const clang warning in user access code

Joel Stanley (3):
  powerpc/boot: Fix crt0.S syntax for clang
  powerpc/boot: Ensure _zimage_start is a weak symbol
  powerpc: Remove -mno-sched-epilog

 arch/powerpc/Makefile                    | 7 +------
 arch/powerpc/boot/crt0.S                 | 8 +++++---
 arch/powerpc/include/asm/uaccess.h       | 6 +++---
 arch/powerpc/kernel/Makefile             | 8 ++++----
 arch/powerpc/kernel/trace/Makefile       | 2 +-
 arch/powerpc/platforms/powermac/Makefile | 2 +-
 arch/powerpc/xmon/Makefile               | 2 +-
 7 files changed, 16 insertions(+), 19 deletions(-)

-- 
2.17.1

^ permalink raw reply

* [PATCH v2 1/5] powerpc/Makefiles: Fix clang/llvm build
From: Joel Stanley @ 2018-09-14  4:06 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Anton Blanchard, Anton Blanchard, Nick Desaulniers
In-Reply-To: <20180914040649.1794-1-joel@jms.id.au>

From: Anton Blanchard <anton@samba.org>

Commit 15a3204d24a3 ("powerpc/64s: Set assembler machine type to POWER4")
passes -mpower4 to the assembler. We have more recent instructions in our
assembly files, but gas permits them. The clang/llvm integrated assembler
is more strict, and we get a build failure.

Fix this by calling the assembler with -mcpu=power8 if as supports it,
else fall back to power4.

Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
 arch/powerpc/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 11a1acba164a..a70639482053 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -238,7 +238,7 @@ cpu-as-$(CONFIG_4xx)		+= -Wa,-m405
 cpu-as-$(CONFIG_ALTIVEC)	+= $(call as-option,-Wa$(comma)-maltivec)
 cpu-as-$(CONFIG_E200)		+= -Wa,-me200
 cpu-as-$(CONFIG_E500)		+= -Wa,-me500
-cpu-as-$(CONFIG_PPC_BOOK3S_64)	+= -Wa,-mpower4
+cpu-as-$(CONFIG_PPC_BOOK3S_64)	+= $(call as-option,-Wa$(comma)-mpower8,-Wa$(comma)-mpower4)
 cpu-as-$(CONFIG_PPC_E500MC)	+= $(call as-option,-Wa$(comma)-me500mc)
 
 KBUILD_AFLAGS += $(cpu-as-y)
-- 
2.17.1

^ permalink raw reply related

* [PATCH v2 2/5] powerpc/boot: Fix crt0.S syntax for clang
From: Joel Stanley @ 2018-09-14  4:06 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Anton Blanchard, Nick Desaulniers
In-Reply-To: <20180914040649.1794-1-joel@jms.id.au>

Clang's assembler does not like the syntax of the cmpdi:

 arch/powerpc/boot/crt0.S:168:22: error: unexpected modifier on variable reference
         cmpdi   12,RELACOUNT@l
                              ^
 arch/powerpc/boot/crt0.S:168:11: error: unknown operand
         cmpdi   12,RELACOUNT@l
                   ^
Enclosing RELACOUNT in () makes it is happy. Tested with GCC 8 and Clang
8 (trunk).

Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38945

Signed-off-by: Joel Stanley <joel@jms.id.au>
---
v2: Fix for !powerpc64 too, add bug link to commit message
---
 arch/powerpc/boot/crt0.S | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S
index dcf2f15e6797..e453e011d7e7 100644
--- a/arch/powerpc/boot/crt0.S
+++ b/arch/powerpc/boot/crt0.S
@@ -80,7 +80,7 @@ p_base:	mflr	r10		/* r10 now points to runtime addr of p_base */
 	lwz	r9,4(r12)	/* get RELA pointer in r9 */
 	b	12f
 11:	addis	r8,r8,(-RELACOUNT)@ha
-	cmpwi	r8,RELACOUNT@l
+	cmpwi	r8,(RELACOUNT)@l
 	bne	12f
 	lwz	r0,4(r12)	/* get RELACOUNT value in r0 */
 12:	addi	r12,r12,8
@@ -165,7 +165,7 @@ p_base:	mflr	r10		/* r10 now points to runtime addr of p_base */
 	ld	r13,8(r11)       /* get RELA pointer in r13 */
 	b	11f
 10:	addis	r12,r12,(-RELACOUNT)@ha
-	cmpdi	r12,RELACOUNT@l
+	cmpdi	r12,(RELACOUNT)@l
 	bne	11f
 	ld	r8,8(r11)       /* get RELACOUNT value in r8 */
 11:	addi	r11,r11,16
-- 
2.17.1

^ permalink raw reply related

* [PATCH v2 3/5] powerpc/boot: Ensure _zimage_start is a weak symbol
From: Joel Stanley @ 2018-09-14  4:06 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Anton Blanchard, Nick Desaulniers
In-Reply-To: <20180914040649.1794-1-joel@jms.id.au>

When building with clang crt0's _zimage_start is not marked weak, which
breaks the build when linking the kernel image:

 $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$
 0000000000000058 g       .text  0000000000000000 _zimage_start

 ld: arch/powerpc/boot/wrapper.a(crt0.o): in function '_zimage_start':
 (.text+0x58): multiple definition of '_zimage_start';
 arch/powerpc/boot/pseries-head.o:(.text+0x0): first defined here

Clang requires the .weak directive to appear after the symbol is
declared. The binutils manual says:

 This directive sets the weak attribute on the comma separated list of
 symbol names. If the symbols do not already exist, they will be
 created.

So it appears this is different with clang. The only reference I could
see for this was an OpenBSD mailing list post[1].

Changing it to be after the declaration fixes building with Clang, and
still works with GCC.

 $ objdump -t arch/powerpc/boot/crt0.o |grep _zimage_start$
 0000000000000058  w      .text	0000000000000000 _zimage_start

Reported to clang as https://bugs.llvm.org/show_bug.cgi?id=38921

[1] https://groups.google.com/forum/#!topic/fa.openbsd.tech/PAgKKen2YCY

Signed-off-by: Joel Stanley <joel@jms.id.au>
---
v2: Add comment explaining this is a workaround for clang. I have also
opened a clang bug to see if they plan on changing behaviour
---
 arch/powerpc/boot/crt0.S | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S
index e453e011d7e7..4e32bd251b99 100644
--- a/arch/powerpc/boot/crt0.S
+++ b/arch/powerpc/boot/crt0.S
@@ -47,8 +47,10 @@ p_end:		.long	_end
 p_pstack:	.long	_platform_stack_top
 #endif
 
-	.weak	_zimage_start
 	.globl	_zimage_start
+	/* Clang appears to require the .weak directive to be after the symbol
+	 * is defined. See https://bugs.llvm.org/show_bug.cgi?id=38921  */
+	.weak	_zimage_start
 _zimage_start:
 	.globl	_zimage_start_lib
 _zimage_start_lib:
-- 
2.17.1

^ permalink raw reply related

* [PATCH v2 4/5] powerpc: Fix duplicate const clang warning in user access code
From: Joel Stanley @ 2018-09-14  4:06 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Anton Blanchard, Anton Blanchard, Nick Desaulniers
In-Reply-To: <20180914040649.1794-1-joel@jms.id.au>

From: Anton Blanchard <anton@samba.org>

This re-applies b91c1e3e7a6f which was reverted in f2ca80905929
d466f6c5cac1 f84ed59a612d (powerpc/sparse: Constify the address pointer
...").

We see a large number of duplicate const errors in the user access
code when building with llvm/clang:

  include/linux/pagemap.h:576:8: warning: duplicate 'const' declaration specifier
      [-Wduplicate-decl-specifier]
        ret = __get_user(c, uaddr);

The problem is we are doing const __typeof__(*(ptr)), which will hit the
warning if ptr is marked const.

Removing const does not seem to have any effect on GCC code generation.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
If we don't want to apply this, other options are suppressing the
warning, or wait for a fix to land in clang
(https://github.com/ClangBuiltLinux/linux/issues/52).
---
 arch/powerpc/include/asm/uaccess.h | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
index bac225bb7f64..15bea9a0f260 100644
--- a/arch/powerpc/include/asm/uaccess.h
+++ b/arch/powerpc/include/asm/uaccess.h
@@ -260,7 +260,7 @@ do {								\
 ({								\
 	long __gu_err;						\
 	__long_type(*(ptr)) __gu_val;				\
-	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
+	__typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
 	__chk_user_ptr(ptr);					\
 	if (!is_kernel_addr((unsigned long)__gu_addr))		\
 		might_fault();					\
@@ -274,7 +274,7 @@ do {								\
 ({									\
 	long __gu_err = -EFAULT;					\
 	__long_type(*(ptr)) __gu_val = 0;				\
-	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);		\
+	__typeof__(*(ptr)) __user *__gu_addr = (ptr);		\
 	might_fault();							\
 	if (access_ok(VERIFY_READ, __gu_addr, (size))) {		\
 		barrier_nospec();					\
@@ -288,7 +288,7 @@ do {								\
 ({								\
 	long __gu_err;						\
 	__long_type(*(ptr)) __gu_val;				\
-	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
+	__typeof__(*(ptr)) __user *__gu_addr = (ptr);	\
 	__chk_user_ptr(ptr);					\
 	barrier_nospec();					\
 	__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
-- 
2.17.1

^ permalink raw reply related

* [PATCH v2 5/5] powerpc: Remove -mno-sched-epilog
From: Joel Stanley @ 2018-09-14  4:06 UTC (permalink / raw)
  To: linuxppc-dev; +Cc: Anton Blanchard, Nick Desaulniers
In-Reply-To: <20180914040649.1794-1-joel@jms.id.au>

This effectively reverts 7563dc645853 ("powerpc: Work around gcc's
-fno-omit-frame-pointer bug"), a workaround for a bug in GCC 4.1.3 when
building 2.6.26 kernel.

The flag is not supported by clang, but reading the history of the
bug[1] suggests it is no longer required by supported GCC versions, with
GCC 4.6 now being the minimum.

[1] https://bugzilla.kernel.org/show_bug.cgi?id=11414
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
Last time this was proposed there was an issue reported:

 https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-September/121214.html

If some machines still have an issue, we could instead wrap this in a
flag check.
---
 arch/powerpc/Makefile                    | 5 -----
 arch/powerpc/kernel/Makefile             | 8 ++++----
 arch/powerpc/kernel/trace/Makefile       | 2 +-
 arch/powerpc/platforms/powermac/Makefile | 2 +-
 arch/powerpc/xmon/Makefile               | 2 +-
 5 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index a70639482053..ef8eca40ffef 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -229,11 +229,6 @@ ifdef CONFIG_6xx
 KBUILD_CFLAGS		+= -mcpu=powerpc
 endif
 
-# Work around a gcc code-gen bug with -fno-omit-frame-pointer.
-ifdef CONFIG_FUNCTION_TRACER
-KBUILD_CFLAGS		+= -mno-sched-epilog
-endif
-
 cpu-as-$(CONFIG_4xx)		+= -Wa,-m405
 cpu-as-$(CONFIG_ALTIVEC)	+= $(call as-option,-Wa$(comma)-maltivec)
 cpu-as-$(CONFIG_E200)		+= -Wa,-me200
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 3b66f2c19c84..1e64cfe22a83 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -22,10 +22,10 @@ CFLAGS_prom.o += $(DISABLE_LATENT_ENTROPY_PLUGIN)
 
 ifdef CONFIG_FUNCTION_TRACER
 # Do not trace early boot code
-CFLAGS_REMOVE_cputable.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
-CFLAGS_REMOVE_prom_init.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
-CFLAGS_REMOVE_btext.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
-CFLAGS_REMOVE_prom.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_cputable.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_prom_init.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_btext.o = $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_prom.o = $(CC_FLAGS_FTRACE)
 endif
 
 obj-y				:= cputable.o ptrace.o syscalls.o \
diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
index d22d8bafb643..d868ba42032f 100644
--- a/arch/powerpc/kernel/trace/Makefile
+++ b/arch/powerpc/kernel/trace/Makefile
@@ -7,7 +7,7 @@ subdir-ccflags-$(CONFIG_PPC_WERROR)	:= -Werror
 
 ifdef CONFIG_FUNCTION_TRACER
 # do not trace tracer code
-CFLAGS_REMOVE_ftrace.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE)
 endif
 
 obj32-$(CONFIG_FUNCTION_TRACER)		+= ftrace_32.o
diff --git a/arch/powerpc/platforms/powermac/Makefile b/arch/powerpc/platforms/powermac/Makefile
index f2839eed0f89..561a67d65e4d 100644
--- a/arch/powerpc/platforms/powermac/Makefile
+++ b/arch/powerpc/platforms/powermac/Makefile
@@ -3,7 +3,7 @@ CFLAGS_bootx_init.o  		+= -fPIC
 
 ifdef CONFIG_FUNCTION_TRACER
 # Do not trace early boot code
-CFLAGS_REMOVE_bootx_init.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
+CFLAGS_REMOVE_bootx_init.o = $(CC_FLAGS_FTRACE)
 endif
 
 obj-y				+= pic.o setup.o time.o feature.o pci.o \
diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
index 1bc3abb237cd..93cc1f1b8b61 100644
--- a/arch/powerpc/xmon/Makefile
+++ b/arch/powerpc/xmon/Makefile
@@ -8,7 +8,7 @@ UBSAN_SANITIZE := n
 
 # Disable ftrace for the entire directory
 ORIG_CFLAGS := $(KBUILD_CFLAGS)
-KBUILD_CFLAGS = $(subst -mno-sched-epilog,,$(subst $(CC_FLAGS_FTRACE),,$(ORIG_CFLAGS)))
+KBUILD_CFLAGS = $(subst $(CC_FLAGS_FTRACE),,$(ORIG_CFLAGS))
 
 ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
 
-- 
2.17.1

^ permalink raw reply related

* Re: [PATCH v4] powerpc: Avoid code patching freed init sections
From: Nicholas Piggin @ 2018-09-14  4:22 UTC (permalink / raw)
  To: Michael Neuling
  Cc: mpe, linuxppc-dev, paulus, Haren Myneni, Michal Suchánek,
	Christophe LEROY
In-Reply-To: <20180914011411.3184-1-mikey@neuling.org>

On Fri, 14 Sep 2018 11:14:11 +1000
Michael Neuling <mikey@neuling.org> wrote:

> This stops us from doing code patching in init sections after they've
> been freed.
> 
> In this chain:
>   kvm_guest_init() ->
>     kvm_use_magic_page() ->
>       fault_in_pages_readable() ->
> 	 __get_user() ->
> 	   __get_user_nocheck() ->
> 	     barrier_nospec();
> 
> We have a code patching location at barrier_nospec() and
> kvm_guest_init() is an init function. This whole chain gets inlined,
> so when we free the init section (hence kvm_guest_init()), this code
> goes away and hence should no longer be patched.
> 
> We seen this as userspace memory corruption when using a memory
> checker while doing partition migration testing on powervm (this
> starts the code patching post migration via
> /sys/kernel/mobility/migration). In theory, it could also happen when
> using /sys/kernel/debug/powerpc/barrier_nospec.
> 
> cc: stable@vger.kernel.org # 4.13+
> Signed-off-by: Michael Neuling <mikey@neuling.org>
> 
> ---
> For stable I've marked this as v4.13+ since that's when we refactored
> code-patching.c but it could go back even further than that. In
> reality though, I think we can only hit this since the first
> spectre/meltdown changes.
> 
> v4:
>  Feedback from Christophe Leroy:
>    - init_mem_free -> init_mem_is_free
>    - prlog %lx -> %px
> 
> v3:
>  Add init_mem_free flag to avoid potential race.
>  Feedback from Christophe Leroy:
>    - use init_section_contains()
>    - change order of init test for performance
>    - use pr_debug()
>    - remove blank line
> 
> v2:
>   Print when we skip an address
> ---
>  arch/powerpc/include/asm/setup.h | 1 +
>  arch/powerpc/lib/code-patching.c | 6 ++++++
>  arch/powerpc/mm/mem.c            | 2 ++
>  3 files changed, 9 insertions(+)
> 
> diff --git a/arch/powerpc/include/asm/setup.h b/arch/powerpc/include/asm/setup.h
> index 1a951b0046..1fffbba8d6 100644
> --- a/arch/powerpc/include/asm/setup.h
> +++ b/arch/powerpc/include/asm/setup.h
> @@ -9,6 +9,7 @@ extern void ppc_printk_progress(char *s, unsigned short hex);
>  
>  extern unsigned int rtas_data;
>  extern unsigned long long memory_limit;
> +extern bool init_mem_is_free;
>  extern unsigned long klimit;
>  extern void *zalloc_maybe_bootmem(size_t size, gfp_t mask);
>  
> diff --git a/arch/powerpc/lib/code-patching.c b/arch/powerpc/lib/code-patching.c
> index 850f3b8f4d..6ae2777c22 100644
> --- a/arch/powerpc/lib/code-patching.c
> +++ b/arch/powerpc/lib/code-patching.c
> @@ -28,6 +28,12 @@ static int __patch_instruction(unsigned int *exec_addr, unsigned int instr,
>  {
>  	int err;
>  
> +	/* Make sure we aren't patching a freed init section */
> +	if (init_mem_is_free && init_section_contains(exec_addr, 4)) {
> +		pr_debug("Skipping init section patching addr: 0x%px\n", exec_addr);
> +		return 0;
> +	}

What we should do is a whitelist, make sure it's only patching the
sections we want it to.

That's a bigger job when you consider modules and things too though,
so this looks good for now. Thanks,

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>

^ permalink raw reply

* Re: [PATCH v2 5/5] powerpc: Remove -mno-sched-epilog
From: Nicholas Piggin @ 2018-09-14  5:06 UTC (permalink / raw)
  To: Joel Stanley; +Cc: linuxppc-dev, Nick Desaulniers
In-Reply-To: <20180914040649.1794-6-joel@jms.id.au>

On Fri, 14 Sep 2018 13:36:49 +0930
Joel Stanley <joel@jms.id.au> wrote:

> This effectively reverts 7563dc645853 ("powerpc: Work around gcc's
> -fno-omit-frame-pointer bug"), a workaround for a bug in GCC 4.1.3 when
> building 2.6.26 kernel.
> 
> The flag is not supported by clang, but reading the history of the
> bug[1] suggests it is no longer required by supported GCC versions, with
> GCC 4.6 now being the minimum.
> 
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=11414
> Signed-off-by: Joel Stanley <joel@jms.id.au>
> ---
> Last time this was proposed there was an issue reported:
> 
>  https://lists.ozlabs.org/pipermail/linuxppc-dev/2014-September/121214.html
> 
> If some machines still have an issue, we could instead wrap this in a
> flag check.

I don't think we can remove it completely because up to at least 4.6
maybe 4.8 has problems.

I have a few patches lying around I started looking at this... I'll
send them.

Thanks,
Nick

^ permalink raw reply


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