[PATCH] arm: omap4: Fix omap_barriers_init for generic ioremap changes

Russell King - ARM Linux
2012-01-13T14:05:20Z

On Thu, Jan 12, 2012 at 11:59:51AM -0800, Tony Lindgren wrote:
> * Nicolas Pitre <nico@fluxnic.net> [120112 11:15]:
> > On Thu, 12 Jan 2012, Nicolas Pitre wrote:
> > >
> > > Do you really need that return code?
> > >
> > > It was initially hooked to core_initcall() which requires a return code.
> > > Now that you call it directly you could get rid of it.
> >
> > s/rid of it/rid of the return code/
>
> Well memblock_alloc could fail there

BTW, that's another thing that's wrong here - it can't fail in such a way
that it returns something to you:

phys_addr_t __init memblock_alloc_base(phys_addr_t size, phys_addr_t align, phys_addr_t max_addr)
{
phys_addr_t alloc;

alloc = __memblock_alloc_base(size, align, max_addr);

if (alloc == 0)
panic("ERROR: Failed to allocate 0x%llx bytes below 0x%llx.\n",
(unsigned long long) size, (unsigned long long) max_addr);
return alloc;
}

phys_addr_t __init memblock_alloc(phys_addr_t size, phys_addr_t align)
{
return memblock_alloc_base(size, align, MEMBLOCK_ALLOC_ACCESSIBLE);
}

So all these tests for zero addresses returned from memblock_alloc()
in the OMAP code need to be killed off.

Actually, I'll do it myself - especially as I'm considering adding
'arm_memblock_steal()' which will barf if it's misused. This makes
the bug in the OMAP4 code glaringly obvious, to the point that OMAP4
will not boot until it's fixed.

8<===
From: Russell King <rmk+kernel@arm.linux.org.uk>
ARM: Add arm_memblock_steal() to allocate memory away from the kernel

Several platforms are now using the memblock_alloc+memblock_free+
memblock_remove trick to obtain memory which won't be mapped in the
kernel's page tables. Most platforms do this (correctly) in the
->reserve callback. However, OMAP has started to call these functions
outside of this callback, and this is extremely unsafe - memory will
not be unmapped, and could well be given out after memblock is no
longer responsible for its management.

So, provide arm_memblock_steal() to perform this function, and ensure
that it panic()s if it is used inappropriately. Convert everyone
over, including OMAP.

As a result, OMAP will panic on boot with this change. OMAP needs to
be fixed, or 137d105d50 (ARM: OMAP4: Fix errata i688 with MPU
interconnect barriers.) reverted until such time it can be fixed
correctly.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
---
arch/arm/include/asm/memblock.h | 2 ++
arch/arm/mach-imx/mach-mx31_3ds.c | 5 ++---
arch/arm/mach-imx/mach-mx31moboard.c | 5 ++---
arch/arm/mach-imx/mach-pcm037.c | 5 ++---
arch/arm/mach-omap2/omap-secure.c | 13 ++-----------
arch/arm/mach-omap2/omap4-common.c | 10 +++-------
arch/arm/mm/init.c | 17 +++++++++++++++++
arch/arm/plat-omap/devices.c | 5 ++---
8 files changed, 32 insertions(+), 30 deletions(-)

diff --git a/arch/arm/include/asm/memblock.h b/arch/arm/include/asm/memblock.h
index b8da2e4..00ca5f9 100644
--- a/arch/arm/include/asm/memblock.h
+++ b/arch/arm/include/asm/memblock.h
@@ -6,4 +6,6 @@ struct machine_desc;

extern void arm_memblock_init(struct meminfo *, struct machine_desc *);

+phys_addr_t arm_memblock_steal(phys_addr_t size, phys_addr_t align);
+
#endif
diff --git a/arch/arm/mach-imx/mach-mx31_3ds.c b/arch/arm/mach-imx/mach-mx31_3ds.c
index 89c3325..4d1aab1 100644
--- a/arch/arm/mach-imx/mach-mx31_3ds.c
+++ b/arch/arm/mach-imx/mach-mx31_3ds.c
@@ -36,6 +36,7 @@
#include <asm/mach/time.h>
#include <asm/memory.h>
#include <asm/mach/map.h>
+#include <asm/memblock.h>
#include <mach/common.h>
#include <mach/iomux-mx3.h>
#include <mach/3ds_debugboard.h>
@@ -754,10 +755,8 @@ static struct sys_timer mx31_3ds_timer = {
static void __init mx31_3ds_reserve(void)
{
/* reserve MX31_3DS_CAMERA_BUF_SIZE bytes for mx3-camera */
- mx3_camera_base = memblock_alloc(MX31_3DS_CAMERA_BUF_SIZE,
+ mx3_camera_base = arm_memblock_steal(MX31_3DS_CAMERA_BUF_SIZE,
MX31_3DS_CAMERA_BUF_SIZE);
- memblock_free(mx3_camera_base, MX31_3DS_CAMERA_BUF_SIZE);
- memblock_remove(mx3_camera_base, MX31_3DS_CAMERA_BUF_SIZE);
}

MACHINE_START(MX31_3DS, "Freescale MX31PDK (3DS)")
diff --git a/arch/arm/mach-imx/mach-mx31moboard.c b/arch/arm/mach-imx/mach-mx31moboard.c
index b95981d..f225262 100644
--- a/arch/arm/mach-imx/mach-mx31moboard.c
+++ b/arch/arm/mach-imx/mach-mx31moboard.c
@@ -41,6 +41,7 @@
#include <asm/mach/arch.h>
#include <asm/mach/time.h>
#include <asm/mach/map.h>
+#include <asm/memblock.h>
#include <mach/board-mx31moboard.h>
#include <mach/common.h>
#include <mach/hardware.h>
@@ -584,10 +585,8 @@ struct sys_timer mx31moboard_timer = {
static void __init mx31moboard_reserve(void)
{
/* reserve 4 MiB for mx3-camera */
- mx3_camera_base = memblock_alloc(MX3_CAMERA_BUF_SIZE,
+ mx3_camera_base = arm_memblock_steal(MX3_CAMERA_BUF_SIZE,
MX3_CAMERA_BUF_SIZE);
- memblock_free(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
- memblock_remove(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
}

MACHINE_START(MX31MOBOARD, "EPFL Mobots mx31moboard")
diff --git a/arch/arm/mach-imx/mach-pcm037.c b/arch/arm/mach-imx/mach-pcm037.c
index d7e1516..e48854b 100644
--- a/arch/arm/mach-imx/mach-pcm037.c
+++ b/arch/arm/mach-imx/mach-pcm037.c
@@ -39,6 +39,7 @@
#include <asm/mach/arch.h>
#include <asm/mach/time.h>
#include <asm/mach/map.h>
+#include <asm/memblock.h>
#include <mach/common.h>
#include <mach/hardware.h>
#include <mach/iomux-mx3.h>
@@ -680,10 +681,8 @@ struct sys_timer pcm037_timer = {
static void __init pcm037_reserve(void)
{
/* reserve 4 MiB for mx3-camera */
- mx3_camera_base = memblock_alloc(MX3_CAMERA_BUF_SIZE,
+ mx3_camera_base = arm_memblock_steal(MX3_CAMERA_BUF_SIZE,
MX3_CAMERA_BUF_SIZE);
- memblock_free(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
- memblock_remove(mx3_camera_base, MX3_CAMERA_BUF_SIZE);
}

MACHINE_START(PCM037, "Phytec Phycore pcm037")
diff --git a/arch/arm/mach-omap2/omap-secure.c b/arch/arm/mach-omap2/omap-secure.c
index 69f3c72..d8f8ef4 100644
--- a/arch/arm/mach-omap2/omap-secure.c
+++ b/arch/arm/mach-omap2/omap-secure.c
@@ -16,6 +16,7 @@
#include <linux/memblock.h>

#include <asm/cacheflush.h>
+#include <asm/memblock.h>

#include <mach/omap-secure.h>

@@ -57,20 +58,10 @@ u32 omap_secure_dispatcher(u32 idx, u32 flag, u32 nargs, u32 arg1, u32 arg2,
/* Allocate the memory to save secure ram */
int __init omap_secure_ram_reserve_memblock(void)
{
- phys_addr_t paddr;
u32 size = OMAP_SECURE_RAM_STORAGE;

size = ALIGN(size, SZ_1M);
- paddr = memblock_alloc(size, SZ_1M);
- if (!paddr) {
- pr_err("%s: failed to reserve %x bytes\n",
- __func__, size);
- return -ENOMEM;
- }
- memblock_free(paddr, size);
- memblock_remove(paddr, size);
-
- omap_secure_memblock_base = paddr;
+ omap_secure_memblock_base = arm_memblock_steal(size, SZ_1M);

return 0;
}
diff --git a/arch/arm/mach-omap2/omap4-common.c b/arch/arm/mach-omap2/omap4-common.c
index bc16c81..40a8fbc 100644
--- a/arch/arm/mach-omap2/omap4-common.c
+++ b/arch/arm/mach-omap2/omap4-common.c
@@ -20,6 +20,7 @@
#include <asm/hardware/gic.h>
#include <asm/hardware/cache-l2x0.h>
#include <asm/mach/map.h>
+#include <asm/memblock.h>

#include <plat/irqs.h>
#include <plat/sram.h>
@@ -61,13 +62,8 @@ static int __init omap_barriers_init(void)
return -ENODEV;

size = ALIGN(PAGE_SIZE, SZ_1M);
- paddr = memblock_alloc(size, SZ_1M);
- if (!paddr) {
- pr_err("%s: failed to reserve 4 Kbytes\n", __func__);
- return -ENOMEM;
- }
- memblock_free(paddr, size);
- memblock_remove(paddr, size);
+ paddr = arm_memblock_steal(size, SZ_1M);
+
dram_io_desc[0].virtual = OMAP4_DRAM_BARRIER_VA;
dram_io_desc[0].pfn = __phys_to_pfn(paddr);
dram_io_desc[0].length = size;
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index e34ea8a..6ec1226 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -22,6 +22,7 @@
#include <linux/memblock.h>

#include <asm/mach-types.h>
+#include <asm/memblock.h>
#include <asm/prom.h>
#include <asm/sections.h>
#include <asm/setup.h>
@@ -307,6 +308,22 @@ static void arm_memory_present(void)
}
#endif

+static bool arm_memblock_steal_permitted = true;
+
+phys_addr_t arm_memblock_steal(phys_addr_t size, phys_addr_t align)
+{
+ phys_addr_t phys;
+
+ if (!arm_memblock_steal_permitted)
+ panic("arm_memblock_steal used in an unsafe manner\n");
+
+ phys = memblock_alloc(size, align);
+ memblock_free(phys, size);
+ memblock_remove(phys, size);
+
+ return phys;
+}
+
void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
{
int i;
@@ -349,6 +366,7 @@ void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
if (mdesc->reserve)
mdesc->reserve();

+ arm_memblock_steal_permitted = false;
memblock_allow_resize();
memblock_dump_all();
}
diff --git a/arch/arm/plat-omap/devices.c b/arch/arm/plat-omap/devices.c
index 1971932..60278f4 100644
--- a/arch/arm/plat-omap/devices.c
+++ b/arch/arm/plat-omap/devices.c
@@ -20,6 +20,7 @@
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <asm/mach/map.h>
+#include <asm/memblock.h>

#include <plat/tc.h>
#include <plat/board.h>
@@ -164,14 +165,12 @@ void __init omap_dsp_reserve_sdram_memblock(void)
if (!size)
return;

- paddr = memblock_alloc(size, SZ_1M);
+ paddr = arm_memblock_steal(size, SZ_1M);
if (!paddr) {
pr_err("%s: failed to reserve %x bytes\n",
__func__, size);
return;
}
- memblock_free(paddr, size);
- memblock_remove(paddr, size);

omap_dsp_phys_mempool_base = paddr;
}