On Thu, Feb 10, 2011 at 02:13:13PM +0000, Dave Martin wrote:
> On Thu, Feb 10, 2011 at 2:11 PM, Dave Martin <[email protected]> wrote:
> > Hi, apologies-- didn't see my mail for a bit.
> >
> > I get the problem with this tree and config (which builds with
> > SMP_ON_UP and THUMB2_KERNEL for omap3/4):
> >
> > Tree: git://git.linaro.org/people/dmart/linux-2.6-arm.git
> > dirty/arm/omap-thumb2+merged
> > Config: http://people.linaro.org/~dmart/arm_omap-thumb2+v2_config
Thanks for the config.
> Note that this tree contains some extra patches (though I believe
> nothing is there which should cause the problem), and does not contain
> everything from rmk/devel -- so it's possible this has been fixed in
> the meantime or no longer occurs for some other reason...
No need - I now have some modules which contain SMP alternatives, so we
do need to fix the module loader for this, and keep the SMP alternatives
replacement code around. It's not worth eliminating the code as if we
include an informative printk() to say why we're refusing to load the
module, the string would be larger than the code it eliminates. So, I
think we need to merge the patch below to avoid run-time problems.
Of course, this conflicts rather badly with the p2v stuff...
arch/arm/kernel/head.S | 38 ++++++++++++++++++++++++++------------
arch/arm/kernel/module.c | 22 +++++++++++++++++++++-
2 files changed, 47 insertions(+), 13 deletions(-)
diff --git a/arch/arm/kernel/head.S b/arch/arm/kernel/head.S
index c0225da..f06ff9f 100644
--- a/arch/arm/kernel/head.S
+++ b/arch/arm/kernel/head.S
@@ -391,6 +391,7 @@ ENDPROC(__turn_mmu_on)
#ifdef CONFIG_SMP_ON_UP
+ __INIT
__fixup_smp:
and r3, r9, #0x000f0000 @ architecture version
teq r3, #0x000f0000 @ CPU ID supported?
@@ -415,18 +416,7 @@ __fixup_smp_on_up:
sub r3, r0, r3
add r4, r4, r3
add r5, r5, r3
-2: cmp r4, r5
- movhs pc, lr
- ldmia r4!, {r0, r6}
- ARM( str r6, [r0, r3] )
- THUMB( add r0, r0, r3 )
-#ifdef __ARMEB__
- THUMB( mov r6, r6, ror #16 ) @ Convert word order for
big-endian.
-#endif
- THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two
halfwords
- THUMB( mov r6, r6, lsr #16 ) @ to be robust against
misaligned r3.
- THUMB( strh r6, [r0] )
- b 2b
+ b __do_fixup_smp_on_up
ENDPROC(__fixup_smp)
.align
@@ -440,7 +430,31 @@ smp_on_up:
ALT_SMP(.long 1)
ALT_UP(.long 0)
.popsection
+#endif
+ .text
+__do_fixup_smp_on_up:
+ cmp r4, r5
+ movhs pc, lr
+ ldmia r4!, {r0, r6}
+ ARM( str r6, [r0, r3] )
+ THUMB( add r0, r0, r3 )
+#ifdef __ARMEB__
+ THUMB( mov r6, r6, ror #16 ) @ Convert word order for
big-endian.
#endif
+ THUMB( strh r6, [r0], #2 ) @ For Thumb-2, store as two
halfwords
+ THUMB( mov r6, r6, lsr #16 ) @ to be robust against
misaligned r3.
+ THUMB( strh r6, [r0] )
+ b __do_fixup_smp_on_up
+ENDPROC(__do_fixup_smp_on_up)
+
+ENTRY(fixup_smp)
+ stmfd sp!, {r4 - r6, lr}
+ mov r4, r0
+ add r5, r0, r1
+ mov r3, #0
+ bl __do_fixup_smp_on_up
+ ldmfd sp!, {r4 - r6, pc}
+ENDPROC(fixup_smp)
#include "head-common.S"
diff --git a/arch/arm/kernel/module.c b/arch/arm/kernel/module.c
index 2cfe816..6d4105e 100644
--- a/arch/arm/kernel/module.c
+++ b/arch/arm/kernel/module.c
@@ -22,6 +22,7 @@
#include <asm/pgtable.h>
#include <asm/sections.h>
+#include <asm/smp_plat.h>
#include <asm/unwind.h>
#ifdef CONFIG_XIP_KERNEL
@@ -268,12 +269,28 @@ struct mod_unwind_map {
const Elf_Shdr *txt_sec;
};
+static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr,
+ const Elf_Shdr *sechdrs, const char *name)
+{
+ const Elf_Shdr *s, *se;
+ const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+
+ for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++)
+ if (strcmp(name, secstrs + s->sh_name) == 0)
+ return s;
+
+ return NULL;
+}
+
+extern void fixup_smp(const void *, unsigned long);
+
int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
struct module *mod)
{
+ const Elf_Shdr * __maybe_unused s = NULL;
#ifdef CONFIG_ARM_UNWIND
const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
- const Elf_Shdr *s, *sechdrs_end = sechdrs + hdr->e_shnum;
+ const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum;
struct mod_unwind_map maps[ARM_SEC_MAX];
int i;
@@ -315,6 +332,9 @@ int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr
*sechdrs,
maps[i].txt_sec->sh_addr,
maps[i].txt_sec->sh_size);
#endif
+ s = find_mod_section(hdr, sechdrs, ".alt.smp.init");
+ if (s && !is_smp())
+ fixup_smp((void *)s->sh_addr, s->sh_size);
return 0;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-omap" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
