[RFC 0/8] m5441x: mmu support patchset

[RFC 0/8] m5441x: mmu support patchset

[Yannick GICQUEL]

Hi all,

Here is a patchset proposal for MMU support on Coldfire 5441x serie.

This patchset allows building the mcfmmu on chip without FPU, enable the
elf binary support and report some code from m54xx to m5441x sources
files.

Also, it contains a proposal for uImage generation.


Functional status is OK on kernel v3.14.
But on v4.2-rc1, we observe a map_err exit fail in do_page_fault().
After bisecting, we point out the regression appears after the
vm_ops->map_pages() feature integration (introduced in 8c6e50b and later)

Your feedbacks are welcome on this.

Best Regards,
Yannick


Yannick GICQUEL (8):
  m68k: coldfire: unlink FPU presence from MMU activation
  m68k: fix build issue in setup_arch() when no FPU
  m68k: add dummy dump_fpu() when FPU is not present
  m68k: m5441x: add ColdFire 5441x CPU MMU memory init code
  m68k: m5441x: fix ACR0 base address when MBAR is not present
  m68k: m5441x: set rambar to end of SRAM physical addr space
  m68k: mmu: add u-boot command line support in setup_arch()
  m68k: uImage generation support

 arch/m68k/Kconfig                |  2 +-
 arch/m68k/Kconfig.cpu            |  4 +-
 arch/m68k/Makefile               |  8 +++-
 arch/m68k/boot/Makefile          | 45 ++++++++++++++++++++++
 arch/m68k/coldfire/head.S        |  9 +++++
 arch/m68k/coldfire/m5441x.c      | 47 +++++++++++++++++++++++
 arch/m68k/include/asm/m54xxacr.h | 13 ++++++-
 arch/m68k/kernel/process.c       |  6 ++-
 arch/m68k/kernel/setup_mm.c      | 82 +++++++++++++++++++++++++++++++++++++++-
 9 files changed, 209 insertions(+), 7 deletions(-)
 create mode 100644 arch/m68k/boot/Makefile

-- 
1.9.1.286.g5172cb3

[RFC 1/8] m68k: coldfire: unlink FPU presence from MMU activation

[Yannick GICQUEL]

m5441x coldfire chips contains a MMU and no FPU.
This patch allow building this chip with MMU activated.

Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
---
 arch/m68k/Kconfig     | 2 +-
 arch/m68k/Kconfig.cpu | 4 +++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 2dd8f63..d704c16 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -14,7 +14,7 @@ config M68K
 	select GENERIC_IOMAP
 	select GENERIC_STRNCPY_FROM_USER if MMU
 	select GENERIC_STRNLEN_USER if MMU
-	select FPU if MMU
+	select FPU if MMU && !COLDFIRE
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE
 	select HAVE_FUTEX_CMPXCHG if MMU && FUTEX
diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
index 33013df..3661eb4 100644
--- a/arch/m68k/Kconfig.cpu
+++ b/arch/m68k/Kconfig.cpu
@@ -257,6 +257,7 @@ config M54xx
 config M547x
 	bool "MCF547x"
 	select M54xx
+	select FPU
 	select MMU_COLDFIRE if MMU
 	select HAVE_CACHE_CB
 	select HAVE_MBAR
@@ -265,6 +266,7 @@ config M547x
 
 config M548x
 	bool "MCF548x"
+	select FPU
 	select MMU_COLDFIRE if MMU
 	select M54xx
 	select HAVE_CACHE_CB
@@ -274,7 +276,7 @@ config M548x
 
 config M5441x
 	bool "MCF5441x"
-	depends on !MMU
+	select MMU_COLDFIRE if MMU
 	select GENERIC_CLOCKEVENTS
 	select HAVE_CACHE_CB
 	help
-- 
1.9.1.286.g5172cb3

[RFC 2/8] m68k: fix build issue in setup_arch() when no FPU

[Yannick GICQUEL]

When MMU is activated, assembler generates an illegal
instruction on target without FPU.
Related code under FPU flag condition.

Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
---
 arch/m68k/kernel/setup_mm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c
index 5b8ec4d..0bc6f77 100644
--- a/arch/m68k/kernel/setup_mm.c
+++ b/arch/m68k/kernel/setup_mm.c
@@ -245,7 +245,7 @@ void __init setup_arch(char **cmdline_p)
 	 * We should really do our own FPU check at startup.
 	 * [what do we do with buggy 68LC040s? if we have problems
 	 *  with them, we should add a test to check_bugs() below] */
-#ifndef CONFIG_M68KFPU_EMU_ONLY
+#if !defined(CONFIG_M68KFPU_EMU_ONLY) && defined(CONFIG_FPU)
 	/* clear the fpu if we have one */
 	if (m68k_fputype & (FPU_68881|FPU_68882|FPU_68040|FPU_68060|FPU_COLDFIRE)) {
 		volatile int zero = 0;
-- 
1.9.1.286.g5172cb3

[RFC 3/8] m68k: add dummy dump_fpu() when FPU is not present

[Yannick GICQUEL]

This is requirement from elfcore.h
No other arch put this one under flag, so this alignment
for build with elf binary support to succeed.

Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
---
 arch/m68k/kernel/process.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index c55ff71..03e29a4 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -203,9 +203,9 @@ int copy_thread(unsigned long clone_flags, unsigned long usp,
 }
 
 /* Fill in the fpu structure for a core dump.  */
-#ifdef CONFIG_FPU
 int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 {
+#ifdef CONFIG_FPU
 	char fpustate[216];
 
 	if (FPU_IS_EMU) {
@@ -250,9 +250,11 @@ int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu)
 	}
 
 	return 1;
+#else
+	return 0;
+#endif /* CONFIG_FPU */
 }
 EXPORT_SYMBOL(dump_fpu);
-#endif /* CONFIG_FPU */
 
 unsigned long get_wchan(struct task_struct *p)
 {
-- 
1.9.1.286.g5172cb3

[RFC 4/8] m68k: m5441x: add ColdFire 5441x CPU MMU memory init code

[Yannick GICQUEL]

This is same code as currently present in m54xx.c file which
was initially integrated in 88be3515.
This is not very elegant because of source code duplication
but this do the job.

Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
---
 arch/m68k/coldfire/m5441x.c | 47 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/arch/m68k/coldfire/m5441x.c b/arch/m68k/coldfire/m5441x.c
index 98a13cc..5924a21 100644
--- a/arch/m68k/coldfire/m5441x.c
+++ b/arch/m68k/coldfire/m5441x.c
@@ -16,6 +16,13 @@
 #include <asm/mcfdma.h>
 #include <asm/mcfclk.h>
 
+#ifdef CONFIG_MMU
+#include <linux/mm.h>
+#include <linux/bootmem.h>
+#include <asm/pgalloc.h>
+#include <asm/mmu_context.h>
+#endif
+
 DEFINE_CLK(0, "flexbus", 2, MCF_CLK);
 DEFINE_CLK(0, "mcfcan.0", 8, MCF_CLK);
 DEFINE_CLK(0, "mcfcan.1", 9, MCF_CLK);
@@ -215,8 +222,48 @@ static void __init m5441x_fec_init(void)
 	__raw_writeb(0x03, MCFGPIO_PAR_FEC);
 }
 
+
+#ifdef CONFIG_MMU
+
+unsigned long num_pages;
+
+static void __init mcf54xx_bootmem_alloc(void)
+{
+	unsigned long start_pfn;
+	unsigned long memstart;
+
+	/* _rambase and _ramend will be naturally page aligned */
+	m68k_memory[0].addr = _rambase;
+	m68k_memory[0].size = _ramend - _rambase;
+
+	/* compute total pages in system */
+	num_pages = (_ramend - _rambase) >> PAGE_SHIFT;
+
+	/* page numbers */
+	memstart = PAGE_ALIGN(_ramstart);
+	min_low_pfn = _rambase >> PAGE_SHIFT;
+	start_pfn = memstart >> PAGE_SHIFT;
+	max_low_pfn = _ramend >> PAGE_SHIFT;
+	high_memory = (void *)_ramend;
+
+	m68k_virt_to_node_shift = fls(_ramend - _rambase - 1) - 6;
+	module_fixup(NULL, __start_fixup, __stop_fixup);
+
+	/* setup bootmem data */
+	m68k_setup_node(0);
+	memstart += init_bootmem_node(NODE_DATA(0), start_pfn,
+		min_low_pfn, max_low_pfn);
+	free_bootmem_node(NODE_DATA(0), memstart, _ramend - memstart);
+}
+#endif /* CONFIG_MMU */
+
+
 void __init config_BSP(char *commandp, int size)
 {
+#ifdef CONFIG_MMU
+	mcf54xx_bootmem_alloc();
+	mmu_context_init();
+#endif
 	m5441x_clk_init();
 	mach_sched_init = hw_timer_init;
 	m5441x_uarts_init();
-- 
1.9.1.286.g5172cb3

[RFC 5/8] m68k: m5441x: fix ACR0 base address when MBAR is not present

[Yannick GICQUEL]

Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
---
 arch/m68k/include/asm/m54xxacr.h | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/m68k/include/asm/m54xxacr.h b/arch/m68k/include/asm/m54xxacr.h
index 6d13cae..e79f48e 100644
--- a/arch/m68k/include/asm/m54xxacr.h
+++ b/arch/m68k/include/asm/m54xxacr.h
@@ -94,8 +94,20 @@
  *	register region as non-cacheable. And then we map all our RAM as
  *	cacheable and supervisor access only.
  */
+#ifdef CONFIG_M5441x
+/*
+ * MBAR register is not present in this serie
+ *  Periph #0 in 0xe0000000--0x0xefffffff
+ *  Periph #1 in 0xf0000000--0x0xffffffff
+ *
+ * Let's hardcode these values for ACR0
+ */
+#define ACR0_MODE	(ACR_BA(0xE0000000)+ACR_ADMSK(0x20000000)+ \
+			 ACR_ENABLE+ACR_SUPER+ACR_CM_OFF_PRE+ACR_SP)
+#else
 #define ACR0_MODE	(ACR_BA(CONFIG_MBAR)+ACR_ADMSK(0x1000000)+ \
 			 ACR_ENABLE+ACR_SUPER+ACR_CM_OFF_PRE+ACR_SP)
+#endif
 #if defined(CONFIG_CACHE_COPYBACK)
 #define ACR1_MODE	(ACR_BA(CONFIG_RAMBASE)+ACR_ADMSK(CONFIG_RAMSIZE)+ \
 			 ACR_ENABLE+ACR_SUPER+ACR_SP+ACR_CM_CP)
@@ -106,7 +118,6 @@
 #define ACR2_MODE	0
 #define ACR3_MODE	(ACR_BA(CONFIG_RAMBASE)+ACR_ADMSK(CONFIG_RAMSIZE)+ \
 			 ACR_ENABLE+ACR_SUPER+ACR_SP)
-
 #else
 
 /*
-- 
1.9.1.286.g5172cb3

[RFC 6/8] m68k: m5441x: set rambar to end of SRAM physical addr space

[Yannick GICQUEL]

Even if SRAM is not used, this is required to avoid inconsistency at runtime.
Otherwise, an assertion failed in ld.so during init process execution:

Inconsistency detected by ld.so: rtld.c: 1290: dl_main: Assertion `_rtld_local._dl_rtld_map.l_libname' failed!

Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
---
 arch/m68k/coldfire/head.S | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/m68k/coldfire/head.S b/arch/m68k/coldfire/head.S
index fa31be2..bf39885 100644
--- a/arch/m68k/coldfire/head.S
+++ b/arch/m68k/coldfire/head.S
@@ -151,6 +151,15 @@ _start0:
 
 _start:
 	nop					/* filler */
+#if defined(CONFIG_M5441x)
+#if defined(CONFIG_SRAM_BASE)
+	movel	#(CONFIG_SRAM_BASE+0x221), %d0
+#else
+	movel	#(0x8ff00000+0x221), %d0
+#endif
+	movec	%d0, %rambar1
+#endif
+
 	movew	#0x2700, %sr			/* no interrupts */
 	movel	#CACHE_INIT,%d0			/* disable cache */
 	movec	%d0,%CACR
-- 
1.9.1.286.g5172cb3

[RFC 7/8] m68k: mmu: add u-boot command line support in setup_arch()

[Yannick GICQUEL]

This part was ported from setup_no.c

Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
---
 arch/m68k/kernel/setup_mm.c | 80 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 80 insertions(+)

diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c
index 0bc6f77..94be970 100644
--- a/arch/m68k/kernel/setup_mm.c
+++ b/arch/m68k/kernel/setup_mm.c
@@ -225,6 +225,68 @@ static void __init m68k_parse_bootinfo(const struct bi_record *record)
 #endif
 }
 
+#if defined(CONFIG_UBOOT)
+/*
+ * parse_uboot_commandline
+ *
+ * Copies u-boot commandline arguments and store them in the proper linux
+ * variables.
+ *
+ * Assumes:
+ *	_init_sp global contains the address in the stack pointer when the
+ *	kernel starts (see head.S::_start)
+ *
+ *	U-Boot calling convention:
+ *	(*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
+ *
+ *	_init_sp can be parsed as such
+ *
+ *	_init_sp+00 = u-boot cmd after jsr into kernel (skip)
+ *	_init_sp+04 = &kernel board_info (residual data)
+ *	_init_sp+08 = &initrd_start
+ *	_init_sp+12 = &initrd_end
+ *	_init_sp+16 = &cmd_start
+ *	_init_sp+20 = &cmd_end
+ *
+ *	This also assumes that the memory locations pointed to are still
+ *	unmodified. U-boot places them near the end of external SDRAM.
+ *
+ * Argument(s):
+ *	commandp = the linux commandline arg container to fill.
+ *	size     = the sizeof commandp.
+ *
+ * Returns:
+ */
+static void __init parse_uboot_commandline(char *commandp, int size)
+{
+	extern unsigned long _init_sp;
+	unsigned long *sp;
+	unsigned long uboot_kbd;
+	unsigned long uboot_initrd_start, uboot_initrd_end;
+	unsigned long uboot_cmd_start, uboot_cmd_end;
+
+
+	sp = (unsigned long *)_init_sp;
+	uboot_kbd = sp[1];
+	uboot_initrd_start = sp[2];
+	uboot_initrd_end = sp[3];
+	uboot_cmd_start = sp[4];
+	uboot_cmd_end = sp[5];
+
+	if (uboot_cmd_start && uboot_cmd_end)
+		strncpy(commandp, (const char *)uboot_cmd_start, size);
+#if defined(CONFIG_BLK_DEV_INITRD)
+	if (uboot_initrd_start && uboot_initrd_end &&
+		(uboot_initrd_end > uboot_initrd_start)) {
+		initrd_start = uboot_initrd_start;
+		initrd_end = uboot_initrd_end;
+		printk(KERN_INFO "initrd at 0x%lx:0x%lx\n",
+			initrd_start, initrd_end);
+	}
+#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
+}
+#endif /* #if defined(CONFIG_UBOOT) */
+
 void __init setup_arch(char **cmdline_p)
 {
 #ifndef CONFIG_SUN3
@@ -274,6 +336,24 @@ void __init setup_arch(char **cmdline_p)
 	strncpy(m68k_command_line, CONFIG_BOOTPARAM_STRING, CL_SIZE);
 	m68k_command_line[CL_SIZE - 1] = 0;
 #endif /* CONFIG_BOOTPARAM */
+
+#if defined(CONFIG_UBOOT)
+	/* CONFIG_UBOOT and CONFIG_BOOTPARAM defined, concatenate cmdline */
+	#if defined(CONFIG_BOOTPARAM)
+		/* Add the whitespace separator */
+		m68k_command_line[strlen(CONFIG_BOOTPARAM_STRING)] = ' ';
+		/* Parse uboot command line into the rest of the buffer */
+		parse_uboot_commandline(
+			&m68k_command_line[(strlen(CONFIG_BOOTPARAM_STRING)+1)],
+			(sizeof(m68k_command_line) -
+			(strlen(CONFIG_BOOTPARAM_STRING)+1)));
+	/* Only CONFIG_UBOOT defined, create cmdline */
+	#else
+		parse_uboot_commandline(&m68k_command_line[0], sizeof(m68k_command_line));
+	#endif /* CONFIG_BOOTPARAM */
+	m68k_command_line[sizeof(m68k_command_line) - 1] = 0;
+#endif /* CONFIG_UBOOT */
+
 	*cmdline_p = m68k_command_line;
 	memcpy(boot_command_line, *cmdline_p, CL_SIZE);
 
-- 
1.9.1.286.g5172cb3

[RFC 8/8] m68k: uImage generation support

[Yannick GICQUEL]

Adding an arch/m68k/boot subdirectory as output dir
for generated uImage.

Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
---
 arch/m68k/Makefile      |  8 +++++++-
 arch/m68k/boot/Makefile | 45 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+), 1 deletion(-)
 create mode 100644 arch/m68k/boot/Makefile

diff --git a/arch/m68k/Makefile b/arch/m68k/Makefile
index 0b29dcf..bf5cbdd 100644
--- a/arch/m68k/Makefile
+++ b/arch/m68k/Makefile
@@ -118,7 +118,6 @@ core-$(CONFIG_M68360)		+= arch/m68k/68360/
 core-$(CONFIG_M68000)		+= arch/m68k/68000/
 core-$(CONFIG_COLDFIRE)		+= arch/m68k/coldfire/
 
-
 all:	zImage
 
 lilo:	vmlinux
@@ -154,8 +153,15 @@ else
 	bzip2 -1c vmlinux >vmlinux.bz2
 endif
 
+boot := arch/m68k/boot
+
+uImage: vmlinux
+	$(Q)$(MAKE) $(build)=$(boot) $(boot)/$@
+
 archclean:
 	rm -f vmlinux.gz vmlinux.bz2
+	$(Q)$(MAKE) $(clean)=$(boot)
+
 
 install:
 	sh $(srctree)/arch/m68k/install.sh $(KERNELRELEASE) vmlinux.gz System.map "$(INSTALL_PATH)"
diff --git a/arch/m68k/boot/Makefile b/arch/m68k/boot/Makefile
new file mode 100644
index 0000000..af0b110
--- /dev/null
+++ b/arch/m68k/boot/Makefile
@@ -0,0 +1,45 @@
+#
+# arch/m68k/boot/Makefile
+#
+# based on initial file from Freescale m5441x BSP
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+
+MKIMAGE := $(srctree)/scripts/mkuboot.sh
+
+#
+# Assign safe dummy values if these variables are not defined,
+# in order to suppress error message.
+#
+CONFIG_KERNELBASE	?= 0x40020000
+
+targets := uImage
+
+UIMAGE_LOADADDR		:= $(CONFIG_KERNELBASE)
+UIMAGE_ENTRYADDR	:= $(CONFIG_KERNELBASE)
+UIMAGE_COMPRESSION	?= none
+
+export UIMAGE_LOADADDR UIMAGE_ENTRYADDR UIMAGE_COMPRESSION
+
+ifeq ($(UIMAGE_COMPRESSION),gzip)
+UIMAGE_SRCBIN		:= $(obj)/vmlinux.bin.gz
+else
+UIMAGE_SRCBIN		:= $(obj)/vmlinux.bin
+endif
+
+$(obj)/uImage: $(UIMAGE_SRCBIN) FORCE
+	$(call if_changed,uimage)
+	@echo '  Image $@ is ready'
+
+OBJCOPYFLAGS_vmlinux.bin := -I elf32-m68k -O binary
+$(obj)/vmlinux.bin: vmlinux FORCE
+	$(call if_changed,objcopy)
+
+$(obj)/vmlinux.bin.gz: $(obj)/vmlinux.bin FORCE
+	$(call if_changed,gzip)
+
+clean-files	+= uImage vmlinux.bin vmlinux.bin.gz
+
-- 
1.9.1.286.g5172cb3

Re: [RFC 1/8] m68k: coldfire: unlink FPU presence from MMU activation

[Greg Ungerer]

Hi Yannick,

I think this needs to be two separate patches.
The FPU change is logically one.
The change to the MCF5441x config is another - and it
really needs to be the last one in the series (so that all
the actuall code support is in place first).

Regards
Greg


On 08/07/15 19:51, Yannick GICQUEL wrote:
> m5441x coldfire chips contains a MMU and no FPU.
> This patch allow building this chip with MMU activated.
>
> Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
> ---
>   arch/m68k/Kconfig     | 2 +-
>   arch/m68k/Kconfig.cpu | 4 +++-
>   2 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
> index 2dd8f63..d704c16 100644
> --- a/arch/m68k/Kconfig
> +++ b/arch/m68k/Kconfig
> @@ -14,7 +14,7 @@ config M68K
>   	select GENERIC_IOMAP
>   	select GENERIC_STRNCPY_FROM_USER if MMU
>   	select GENERIC_STRNLEN_USER if MMU
> -	select FPU if MMU
> +	select FPU if MMU && !COLDFIRE
>   	select ARCH_WANT_IPC_PARSE_VERSION
>   	select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE
>   	select HAVE_FUTEX_CMPXCHG if MMU && FUTEX
> diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
> index 33013df..3661eb4 100644
> --- a/arch/m68k/Kconfig.cpu
> +++ b/arch/m68k/Kconfig.cpu
> @@ -257,6 +257,7 @@ config M54xx
>   config M547x
>   	bool "MCF547x"
>   	select M54xx
> +	select FPU
>   	select MMU_COLDFIRE if MMU
>   	select HAVE_CACHE_CB
>   	select HAVE_MBAR
> @@ -265,6 +266,7 @@ config M547x
>
>   config M548x
>   	bool "MCF548x"
> +	select FPU
>   	select MMU_COLDFIRE if MMU
>   	select M54xx
>   	select HAVE_CACHE_CB
> @@ -274,7 +276,7 @@ config M548x
>
>   config M5441x
>   	bool "MCF5441x"
> -	depends on !MMU
> +	select MMU_COLDFIRE if MMU
>   	select GENERIC_CLOCKEVENTS
>   	select HAVE_CACHE_CB
>   	help
>

Re: [RFC 4/8] m68k: m5441x: add ColdFire 5441x CPU MMU memory init code

[Greg Ungerer]

Hi Yannick,

On 08/07/15 19:51, Yannick GICQUEL wrote:
> This is same code as currently present in m54xx.c file which
> was initially integrated in 88be3515.
> This is not very elegant because of source code duplication
> but this do the job.

Perhaps moving into arch/m68k/mm/mcfmmu.c would be better?
No point having two complete copies of the same code.
And none if it is actually specific to the 54xx or 5441xx.

Regards
Greg


> Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
> ---
>   arch/m68k/coldfire/m5441x.c | 47 +++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 47 insertions(+)
>
> diff --git a/arch/m68k/coldfire/m5441x.c b/arch/m68k/coldfire/m5441x.c
> index 98a13cc..5924a21 100644
> --- a/arch/m68k/coldfire/m5441x.c
> +++ b/arch/m68k/coldfire/m5441x.c
> @@ -16,6 +16,13 @@
>   #include <asm/mcfdma.h>
>   #include <asm/mcfclk.h>
>
> +#ifdef CONFIG_MMU
> +#include <linux/mm.h>
> +#include <linux/bootmem.h>
> +#include <asm/pgalloc.h>
> +#include <asm/mmu_context.h>
> +#endif
> +
>   DEFINE_CLK(0, "flexbus", 2, MCF_CLK);
>   DEFINE_CLK(0, "mcfcan.0", 8, MCF_CLK);
>   DEFINE_CLK(0, "mcfcan.1", 9, MCF_CLK);
> @@ -215,8 +222,48 @@ static void __init m5441x_fec_init(void)
>   	__raw_writeb(0x03, MCFGPIO_PAR_FEC);
>   }
>
> +
> +#ifdef CONFIG_MMU
> +
> +unsigned long num_pages;
> +
> +static void __init mcf54xx_bootmem_alloc(void)
> +{
> +	unsigned long start_pfn;
> +	unsigned long memstart;
> +
> +	/* _rambase and _ramend will be naturally page aligned */
> +	m68k_memory[0].addr = _rambase;
> +	m68k_memory[0].size = _ramend - _rambase;
> +
> +	/* compute total pages in system */
> +	num_pages = (_ramend - _rambase) >> PAGE_SHIFT;
> +
> +	/* page numbers */
> +	memstart = PAGE_ALIGN(_ramstart);
> +	min_low_pfn = _rambase >> PAGE_SHIFT;
> +	start_pfn = memstart >> PAGE_SHIFT;
> +	max_low_pfn = _ramend >> PAGE_SHIFT;
> +	high_memory = (void *)_ramend;
> +
> +	m68k_virt_to_node_shift = fls(_ramend - _rambase - 1) - 6;
> +	module_fixup(NULL, __start_fixup, __stop_fixup);
> +
> +	/* setup bootmem data */
> +	m68k_setup_node(0);
> +	memstart += init_bootmem_node(NODE_DATA(0), start_pfn,
> +		min_low_pfn, max_low_pfn);
> +	free_bootmem_node(NODE_DATA(0), memstart, _ramend - memstart);
> +}
> +#endif /* CONFIG_MMU */
> +
> +
>   void __init config_BSP(char *commandp, int size)
>   {
> +#ifdef CONFIG_MMU
> +	mcf54xx_bootmem_alloc();
> +	mmu_context_init();
> +#endif
>   	m5441x_clk_init();
>   	mach_sched_init = hw_timer_init;
>   	m5441x_uarts_init();
>

Re: [RFC 6/8] m68k: m5441x: set rambar to end of SRAM physical addr space

[Greg Ungerer]

Hi Yannick,

On 08/07/15 19:51, Yannick GICQUEL wrote:
> Even if SRAM is not used, this is required to avoid inconsistency at runtime.
> Otherwise, an assertion failed in ld.so during init process execution:
>
> Inconsistency detected by ld.so: rtld.c: 1290: dl_main: Assertion `_rtld_local._dl_rtld_map.l_libname' failed!

Can you explain further?
Is this really the underlying problem?
Surely the presence of the SRAM block mapped in shouldn't
have any impact on running applications.

Where does CONFIG_SRAM_BASE come from?
I didn't see in this series anywhere.

Regards
Greg



> Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
> ---
>   arch/m68k/coldfire/head.S | 9 +++++++++
>   1 file changed, 9 insertions(+)
>
> diff --git a/arch/m68k/coldfire/head.S b/arch/m68k/coldfire/head.S
> index fa31be2..bf39885 100644
> --- a/arch/m68k/coldfire/head.S
> +++ b/arch/m68k/coldfire/head.S
> @@ -151,6 +151,15 @@ _start0:
>
>   _start:
>   	nop					/* filler */
> +#if defined(CONFIG_M5441x)
> +#if defined(CONFIG_SRAM_BASE)
> +	movel	#(CONFIG_SRAM_BASE+0x221), %d0
> +#else
> +	movel	#(0x8ff00000+0x221), %d0
> +#endif
> +	movec	%d0, %rambar1
> +#endif
> +
>   	movew	#0x2700, %sr			/* no interrupts */
>   	movel	#CACHE_INIT,%d0			/* disable cache */
>   	movec	%d0,%CACR
>

Re: [RFC 7/8] m68k: mmu: add u-boot command line support in setup_arch()

[Greg Ungerer]

Hi Yannick,

Again no point having two copies of the same code.
Perhaps merging of the _mm and _no setup code makes
more sense now.

Regards
Greg


On 08/07/15 19:51, Yannick GICQUEL wrote:
> This part was ported from setup_no.c
>
> Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
> ---
>   arch/m68k/kernel/setup_mm.c | 80 +++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 80 insertions(+)
>
> diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c
> index 0bc6f77..94be970 100644
> --- a/arch/m68k/kernel/setup_mm.c
> +++ b/arch/m68k/kernel/setup_mm.c
> @@ -225,6 +225,68 @@ static void __init m68k_parse_bootinfo(const struct bi_record *record)
>   #endif
>   }
>
> +#if defined(CONFIG_UBOOT)
> +/*
> + * parse_uboot_commandline
> + *
> + * Copies u-boot commandline arguments and store them in the proper linux
> + * variables.
> + *
> + * Assumes:
> + *	_init_sp global contains the address in the stack pointer when the
> + *	kernel starts (see head.S::_start)
> + *
> + *	U-Boot calling convention:
> + *	(*kernel) (kbd, initrd_start, initrd_end, cmd_start, cmd_end);
> + *
> + *	_init_sp can be parsed as such
> + *
> + *	_init_sp+00 = u-boot cmd after jsr into kernel (skip)
> + *	_init_sp+04 = &kernel board_info (residual data)
> + *	_init_sp+08 = &initrd_start
> + *	_init_sp+12 = &initrd_end
> + *	_init_sp+16 = &cmd_start
> + *	_init_sp+20 = &cmd_end
> + *
> + *	This also assumes that the memory locations pointed to are still
> + *	unmodified. U-boot places them near the end of external SDRAM.
> + *
> + * Argument(s):
> + *	commandp = the linux commandline arg container to fill.
> + *	size     = the sizeof commandp.
> + *
> + * Returns:
> + */
> +static void __init parse_uboot_commandline(char *commandp, int size)
> +{
> +	extern unsigned long _init_sp;
> +	unsigned long *sp;
> +	unsigned long uboot_kbd;
> +	unsigned long uboot_initrd_start, uboot_initrd_end;
> +	unsigned long uboot_cmd_start, uboot_cmd_end;
> +
> +
> +	sp = (unsigned long *)_init_sp;
> +	uboot_kbd = sp[1];
> +	uboot_initrd_start = sp[2];
> +	uboot_initrd_end = sp[3];
> +	uboot_cmd_start = sp[4];
> +	uboot_cmd_end = sp[5];
> +
> +	if (uboot_cmd_start && uboot_cmd_end)
> +		strncpy(commandp, (const char *)uboot_cmd_start, size);
> +#if defined(CONFIG_BLK_DEV_INITRD)
> +	if (uboot_initrd_start && uboot_initrd_end &&
> +		(uboot_initrd_end > uboot_initrd_start)) {
> +		initrd_start = uboot_initrd_start;
> +		initrd_end = uboot_initrd_end;
> +		printk(KERN_INFO "initrd at 0x%lx:0x%lx\n",
> +			initrd_start, initrd_end);
> +	}
> +#endif /* if defined(CONFIG_BLK_DEV_INITRD) */
> +}
> +#endif /* #if defined(CONFIG_UBOOT) */
> +
>   void __init setup_arch(char **cmdline_p)
>   {
>   #ifndef CONFIG_SUN3
> @@ -274,6 +336,24 @@ void __init setup_arch(char **cmdline_p)
>   	strncpy(m68k_command_line, CONFIG_BOOTPARAM_STRING, CL_SIZE);
>   	m68k_command_line[CL_SIZE - 1] = 0;
>   #endif /* CONFIG_BOOTPARAM */
> +
> +#if defined(CONFIG_UBOOT)
> +	/* CONFIG_UBOOT and CONFIG_BOOTPARAM defined, concatenate cmdline */
> +	#if defined(CONFIG_BOOTPARAM)
> +		/* Add the whitespace separator */
> +		m68k_command_line[strlen(CONFIG_BOOTPARAM_STRING)] = ' ';
> +		/* Parse uboot command line into the rest of the buffer */
> +		parse_uboot_commandline(
> +			&m68k_command_line[(strlen(CONFIG_BOOTPARAM_STRING)+1)],
> +			(sizeof(m68k_command_line) -
> +			(strlen(CONFIG_BOOTPARAM_STRING)+1)));
> +	/* Only CONFIG_UBOOT defined, create cmdline */
> +	#else
> +		parse_uboot_commandline(&m68k_command_line[0], sizeof(m68k_command_line));
> +	#endif /* CONFIG_BOOTPARAM */
> +	m68k_command_line[sizeof(m68k_command_line) - 1] = 0;
> +#endif /* CONFIG_UBOOT */
> +
>   	*cmdline_p = m68k_command_line;
>   	memcpy(boot_command_line, *cmdline_p, CL_SIZE);
>
>

Re: [RFC 1/8] m68k: coldfire: unlink FPU presence from MMU activation

[Geert Uytterhoeven]

On Wed, Jul 8, 2015 at 11:51 AM, Yannick GICQUEL
<yannick.gicquel@open.eurogiciel.org> wrote:
> diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
> index 2dd8f63..d704c16 100644
> --- a/arch/m68k/Kconfig
> +++ b/arch/m68k/Kconfig
> @@ -14,7 +14,7 @@ config M68K
>         select GENERIC_IOMAP
>         select GENERIC_STRNCPY_FROM_USER if MMU
>         select GENERIC_STRNLEN_USER if MMU
> -       select FPU if MMU
> +       select FPU if MMU && !COLDFIRE

I'm not too fond of having complex dependencies here...

>         select ARCH_WANT_IPC_PARSE_VERSION
>         select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE

(but we already have examples like the above)

>         select HAVE_FUTEX_CMPXCHG if MMU && FUTEX
> diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
> index 33013df..3661eb4 100644
> --- a/arch/m68k/Kconfig.cpu
> +++ b/arch/m68k/Kconfig.cpu
> @@ -257,6 +257,7 @@ config M54xx
>  config M547x
>         bool "MCF547x"
>         select M54xx
> +       select FPU

... perhaps the "select FPU" should be added to M68KCLASSIC, too,
so we can get rid of the top one?

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

Re: [RFC 2/8] m68k: fix build issue in setup_arch() when no FPU

[Geert Uytterhoeven]

On Wed, Jul 8, 2015 at 11:51 AM, Yannick GICQUEL
<yannick.gicquel@open.eurogiciel.org> wrote:
> diff --git a/arch/m68k/kernel/setup_mm.c b/arch/m68k/kernel/setup_mm.c
> index 5b8ec4d..0bc6f77 100644
> --- a/arch/m68k/kernel/setup_mm.c
> +++ b/arch/m68k/kernel/setup_mm.c
> @@ -245,7 +245,7 @@ void __init setup_arch(char **cmdline_p)
>          * We should really do our own FPU check at startup.
>          * [what do we do with buggy 68LC040s? if we have problems
>          *  with them, we should add a test to check_bugs() below] */
> -#ifndef CONFIG_M68KFPU_EMU_ONLY
> +#if !defined(CONFIG_M68KFPU_EMU_ONLY) && defined(CONFIG_FPU)
>         /* clear the fpu if we have one */
>         if (m68k_fputype & (FPU_68881|FPU_68882|FPU_68040|FPU_68060|FPU_COLDFIRE)) {
>                 volatile int zero = 0;

Should we turn M68KFPU_EMU_ONLY into !FPU in general?

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

Re: [RFC 0/8] m5441x: mmu support patchset

[Greg Ungerer]

Hi Yannick,

On 08/07/15 19:51, Yannick GICQUEL wrote:
> Here is a patchset proposal for MMU support on Coldfire 5441x serie.

Nice.


> This patchset allows building the mcfmmu on chip without FPU, enable the
> elf binary support and report some code from m54xx to m5441x sources
> files.
>
> Also, it contains a proposal for uImage generation.
>
>
> Functional status is OK on kernel v3.14.
> But on v4.2-rc1, we observe a map_err exit fail in do_page_fault().
> After bisecting, we point out the regression appears after the
> vm_ops->map_pages() feature integration (introduced in 8c6e50b and later)

I haven't looked in detail into this yet. But I can confirm
that it still works fine on a 5475 with MMU enabled.

Some other comments as replies to specific patches.

Regards
Greg


> Your feedbacks are welcome on this.
>
> Best Regards,
> Yannick
>
>
> Yannick GICQUEL (8):
>    m68k: coldfire: unlink FPU presence from MMU activation
>    m68k: fix build issue in setup_arch() when no FPU
>    m68k: add dummy dump_fpu() when FPU is not present
>    m68k: m5441x: add ColdFire 5441x CPU MMU memory init code
>    m68k: m5441x: fix ACR0 base address when MBAR is not present
>    m68k: m5441x: set rambar to end of SRAM physical addr space
>    m68k: mmu: add u-boot command line support in setup_arch()
>    m68k: uImage generation support
>
>   arch/m68k/Kconfig                |  2 +-
>   arch/m68k/Kconfig.cpu            |  4 +-
>   arch/m68k/Makefile               |  8 +++-
>   arch/m68k/boot/Makefile          | 45 ++++++++++++++++++++++
>   arch/m68k/coldfire/head.S        |  9 +++++
>   arch/m68k/coldfire/m5441x.c      | 47 +++++++++++++++++++++++
>   arch/m68k/include/asm/m54xxacr.h | 13 ++++++-
>   arch/m68k/kernel/process.c       |  6 ++-
>   arch/m68k/kernel/setup_mm.c      | 82 +++++++++++++++++++++++++++++++++++++++-
>   9 files changed, 209 insertions(+), 7 deletions(-)
>   create mode 100644 arch/m68k/boot/Makefile
>

Re: [RFC 1/8] m68k: coldfire: unlink FPU presence from MMU activation

[Greg Ungerer]

On 09/07/15 00:03, Geert Uytterhoeven wrote:
> On Wed, Jul 8, 2015 at 11:51 AM, Yannick GICQUEL
> <yannick.gicquel@open.eurogiciel.org> wrote:
>> diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
>> index 2dd8f63..d704c16 100644
>> --- a/arch/m68k/Kconfig
>> +++ b/arch/m68k/Kconfig
>> @@ -14,7 +14,7 @@ config M68K
>>          select GENERIC_IOMAP
>>          select GENERIC_STRNCPY_FROM_USER if MMU
>>          select GENERIC_STRNLEN_USER if MMU
>> -       select FPU if MMU
>> +       select FPU if MMU && !COLDFIRE
>
> I'm not too fond of having complex dependencies here...
>
>>          select ARCH_WANT_IPC_PARSE_VERSION
>>          select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE
>
> (but we already have examples like the above)
>
>>          select HAVE_FUTEX_CMPXCHG if MMU && FUTEX
>> diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
>> index 33013df..3661eb4 100644
>> --- a/arch/m68k/Kconfig.cpu
>> +++ b/arch/m68k/Kconfig.cpu
>> @@ -257,6 +257,7 @@ config M54xx
>>   config M547x
>>          bool "MCF547x"
>>          select M54xx
>> +       select FPU
>
> ... perhaps the "select FPU" should be added to M68KCLASSIC, too,
> so we can get rid of the top one?

We use M68KCLASSIC for the non-MMU 68k families as well, and none
of those have FPU either. Maybe should we select FPU for each of
M68020, M68030, M68040 and M68060 in their configs?

Regards
Greg


> --
> 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
> --
> To unsubscribe from this list: send the line "unsubscribe linux-m68k" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

Re: [RFC 1/8] m68k: coldfire: unlink FPU presence from MMU activation

[Geert Uytterhoeven]

On Wed, Jul 8, 2015 at 4:12 PM, Greg Ungerer <gregungerer@westnet.com.au> wrote:
>>> --- a/arch/m68k/Kconfig.cpu
>>> +++ b/arch/m68k/Kconfig.cpu
>>> @@ -257,6 +257,7 @@ config M54xx
>>>   config M547x
>>>          bool "MCF547x"
>>>          select M54xx
>>> +       select FPU
>>
>>
>> ... perhaps the "select FPU" should be added to M68KCLASSIC, too,
>> so we can get rid of the top one?
>
>
> We use M68KCLASSIC for the non-MMU 68k families as well, and none
> of those have FPU either. Maybe should we select FPU for each of
> M68020, M68030, M68040 and M68060 in their configs?

Yep, makes sense.

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

Re: [RFC 0/8] m5441x: mmu support patchset

[Yannick GICQUEL]

Hi Greg, Geert,

Sorry for late response and thanks for your reviews and comments,

These patchs can gives an overview of the work that *seem* required for MMU
support on 5441x, but clearly there still some unknown behaviour under 
study.
It looks like the address translation is not always took into account by 
HW, but this
needs a deeper investigation which is on going.

This is good to know the 5475 MMU support is Ok on latest kernel version.
I have checked deeper in datasheets to study differences. MMU are quite 
similar,
but few differences are present.

At register level, there are additional bits on M5441x serie :

MMUCR[UVE] : User virtual mode enable.
     0: Virtual mode activation based on MMUCR[EN], (default)
     1: based on MMUCR[EN] && CPU *not* in Supervisor mode.

MMUCR[SAL] : Select ASID location
     0: defined by ASID register, (default)
     1: defined by MMUAR[9:2]

 From my understanding of current CFV4e MMU support, I think the MMUCR[SAL]
needs to be set. ASID register is set in head.S but *not* used in 
cf_tlb_miss() missed.

Regarding MMUCR[UVE], I think the default configuration is coherent with 
address
translation requirement while running in kernel mode.


Another difference between M5441x & 5475 is Peripheral memory mapping 
which is
relative to MBAR ( == 0xff000000 in defconfig ) register on 5475, and 
fixed on M5441x.
Also, physical RAM is accessible from 0x40000000 on m5441x, and starts 
at 0x0 on 5475.

Don't think it should have an impact on the virtual address translation 
mechanism, but
if for some reason this is faulty or disable at some point, there may be 
an "overlap"
between virtual and physical address space on 5441x which is not present 
on 5475.
Just an assumption...


Other comments in threads as well.

Best Regards,
Yannick


Le 08/07/2015 16:07, Greg Ungerer a écrit :
> Hi Yannick,
>
> On 08/07/15 19:51, Yannick GICQUEL wrote:
>> Here is a patchset proposal for MMU support on Coldfire 5441x serie.
>
> Nice.
>
>
>> This patchset allows building the mcfmmu on chip without FPU, enable the
>> elf binary support and report some code from m54xx to m5441x sources
>> files.
>>
>> Also, it contains a proposal for uImage generation.
>>
>>
>> Functional status is OK on kernel v3.14.
>> But on v4.2-rc1, we observe a map_err exit fail in do_page_fault().
>> After bisecting, we point out the regression appears after the
>> vm_ops->map_pages() feature integration (introduced in 8c6e50b and 
>> later)
>
> I haven't looked in detail into this yet. But I can confirm
> that it still works fine on a 5475 with MMU enabled.

>
> Some other comments as replies to specific patches.
>
> Regards
> Greg
>
>
>> Your feedbacks are welcome on this.
>>
>> Best Regards,
>> Yannick
>>
>>
>> Yannick GICQUEL (8):
>>    m68k: coldfire: unlink FPU presence from MMU activation
>>    m68k: fix build issue in setup_arch() when no FPU
>>    m68k: add dummy dump_fpu() when FPU is not present
>>    m68k: m5441x: add ColdFire 5441x CPU MMU memory init code
>>    m68k: m5441x: fix ACR0 base address when MBAR is not present
>>    m68k: m5441x: set rambar to end of SRAM physical addr space
>>    m68k: mmu: add u-boot command line support in setup_arch()
>>    m68k: uImage generation support
>>
>>   arch/m68k/Kconfig                |  2 +-
>>   arch/m68k/Kconfig.cpu            |  4 +-
>>   arch/m68k/Makefile               |  8 +++-
>>   arch/m68k/boot/Makefile          | 45 ++++++++++++++++++++++
>>   arch/m68k/coldfire/head.S        |  9 +++++
>>   arch/m68k/coldfire/m5441x.c      | 47 +++++++++++++++++++++++
>>   arch/m68k/include/asm/m54xxacr.h | 13 ++++++-
>>   arch/m68k/kernel/process.c       |  6 ++-
>>   arch/m68k/kernel/setup_mm.c      | 82 
>> +++++++++++++++++++++++++++++++++++++++-
>>   9 files changed, 209 insertions(+), 7 deletions(-)
>>   create mode 100644 arch/m68k/boot/Makefile
>>
>

Re: [RFC 1/8] m68k: coldfire: unlink FPU presence from MMU activation

[Yannick GICQUEL]

Hi Greg,

Ok with that.
Source code rework and feature activation are two different things.
Keep it in mind for future...

Regards,
Yannick

Le 08/07/2015 15:36, Greg Ungerer a écrit :
> Hi Yannick,
>
> I think this needs to be two separate patches.
> The FPU change is logically one.
> The change to the MCF5441x config is another - and it
> really needs to be the last one in the series (so that all
> the actuall code support is in place first).
>
> Regards
> Greg
>
>
> On 08/07/15 19:51, Yannick GICQUEL wrote:
>> m5441x coldfire chips contains a MMU and no FPU.
>> This patch allow building this chip with MMU activated.
>>
>> Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
>> ---
>>   arch/m68k/Kconfig     | 2 +-
>>   arch/m68k/Kconfig.cpu | 4 +++-
>>   2 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
>> index 2dd8f63..d704c16 100644
>> --- a/arch/m68k/Kconfig
>> +++ b/arch/m68k/Kconfig
>> @@ -14,7 +14,7 @@ config M68K
>>       select GENERIC_IOMAP
>>       select GENERIC_STRNCPY_FROM_USER if MMU
>>       select GENERIC_STRNLEN_USER if MMU
>> -    select FPU if MMU
>> +    select FPU if MMU && !COLDFIRE
>>       select ARCH_WANT_IPC_PARSE_VERSION
>>       select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE
>>       select HAVE_FUTEX_CMPXCHG if MMU && FUTEX
>> diff --git a/arch/m68k/Kconfig.cpu b/arch/m68k/Kconfig.cpu
>> index 33013df..3661eb4 100644
>> --- a/arch/m68k/Kconfig.cpu
>> +++ b/arch/m68k/Kconfig.cpu
>> @@ -257,6 +257,7 @@ config M54xx
>>   config M547x
>>       bool "MCF547x"
>>       select M54xx
>> +    select FPU
>>       select MMU_COLDFIRE if MMU
>>       select HAVE_CACHE_CB
>>       select HAVE_MBAR
>> @@ -265,6 +266,7 @@ config M547x
>>
>>   config M548x
>>       bool "MCF548x"
>> +    select FPU
>>       select MMU_COLDFIRE if MMU
>>       select M54xx
>>       select HAVE_CACHE_CB
>> @@ -274,7 +276,7 @@ config M548x
>>
>>   config M5441x
>>       bool "MCF5441x"
>> -    depends on !MMU
>> +    select MMU_COLDFIRE if MMU
>>       select GENERIC_CLOCKEVENTS
>>       select HAVE_CACHE_CB
>>       help
>>
>

Re: [RFC 6/8] m68k: m5441x: set rambar to end of SRAM physical addr space

[Yannick GICQUEL]

Hi Greg,

Le 08/07/2015 15:53, Greg Ungerer a écrit :
> Hi Yannick,
>
> On 08/07/15 19:51, Yannick GICQUEL wrote:
>> Even if SRAM is not used, this is required to avoid inconsistency at 
>> runtime.
>> Otherwise, an assertion failed in ld.so during init process execution:
>>
>> Inconsistency detected by ld.so: rtld.c: 1290: dl_main: Assertion 
>> `_rtld_local._dl_rtld_map.l_libname' failed!
>
> Can you explain further?
> Is this really the underlying problem?
> Surely the presence of the SRAM block mapped in shouldn't
> have any impact on running applications.

I think this is due to SRAM backdoor default activation on m5441x.

cf. reference manual (p.190):
(...)By default, the RAMBAR is invalid, but the backdoor is enabled. In 
this state, any core accesses to the SRAM are routed through the 
backdoor(...)

Also, i think this backdoor must be disabled. In section 4.3.1.2.3, its 
explained the "the address mode for normal accesses is determined by the 
MMUBAR, RAMBARs, and ACRs in the priority order listed(...)", before 
handling these accesses as virtual addresses.

Thus, when the backdoor is enable, the virtual address translation is 
not performed for the SRAM 64Kb range.


I just realized that i didn't simply try disabling the backdoor by 
setting RAMBAR to 0.
I have just done this test and this seems sufficient to fix the 
assertion failed at ld.so
execution.

> Where does CONFIG_SRAM_BASE come from?
> I didn't see in this series anywhere.
Old "artifact" from initial FSL BSP ; agreed : it should not be 
delivered as is.
Also, may be this code could be moved outside head.S and put in a m5441 
related file... it need a try before patch update.

> Regards
> Greg
>
>
>
>> Signed-off-by: Yannick GICQUEL <yannick.gicquel@gmail.com>
>> ---
>>   arch/m68k/coldfire/head.S | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
>> diff --git a/arch/m68k/coldfire/head.S b/arch/m68k/coldfire/head.S
>> index fa31be2..bf39885 100644
>> --- a/arch/m68k/coldfire/head.S
>> +++ b/arch/m68k/coldfire/head.S
>> @@ -151,6 +151,15 @@ _start0:
>>
>>   _start:
>>       nop                    /* filler */
>> +#if defined(CONFIG_M5441x)
>> +#if defined(CONFIG_SRAM_BASE)
>> +    movel    #(CONFIG_SRAM_BASE+0x221), %d0
>> +#else
>> +    movel    #(0x8ff00000+0x221), %d0
>> +#endif
>> +    movec    %d0, %rambar1
>> +#endif
>> +
>>       movew    #0x2700, %sr            /* no interrupts */
>>       movel    #CACHE_INIT,%d0            /* disable cache */
>>       movec    %d0,%CACR
>>
>