[PATCH] boot/common/util.S: Put flush_{instruction, data}_cache back in .relocate_code section
Paul Janzen
pcj at linux.sez.to
Thu Jan 5 16:40:48 EST 2006
In 2.6.14, we had the following definition of _GLOBAL() in
include/asm-ppc/processor.h:
#define _GLOBAL(n)\
.stabs __stringify(n:F-1),N_FUN,0,0,n;\
.globl n;\
n:
In 2.6.15, as part of the great powerpc merge, we moved this definition to
include/asm-powerpc/ppc_asm.h, where it appears (to 32-bit code) as:
#define _GLOBAL(n) \
.text; \
.stabs __stringify(n:F-1),N_FUN,0,0,n;\
.globl n; \
n:
Mostly, this is fine. However, we also have the following, in
arch/ppc/boot/common/util.S:
.section ".relocate_code","xa"
[...]
_GLOBAL(flush_instruction_cache)
[...]
_GLOBAL(flush_data_cache)
[...]
The addition of the .text section definition in the definition of
_GLOBAL overrides the .relocate_code section definition. As a result,
these two functions don't end up in .relocate_code, so they don't get
relocated correctly, and the boot fails.
There's another suspicious-looking usage at kernel/swsusp.S:37 that
someone should look into. I did not exhaustively search the source
tree, though.
The following is the minimal patch that fixes the immediate problem.
I could easily be convinced that the _GLOBAL definition should be
modified to remove the ".text;" line either instead of, or in addition
to, this fix.
Signed-off-by: Paul Janzen <pcj at linux.sez.to>
--- arch/ppc/boot/common/util.S~ 2005-12-24 15:47:48.000000000 -0800
+++ arch/ppc/boot/common/util.S 2006-01-04 14:07:12.000000000 -0800
@@ -234,7 +234,8 @@ udelay:
* First, flush the data cache in case it was enabled and may be
* holding instructions for copy back.
*/
-_GLOBAL(flush_instruction_cache)
+ .globl flush_instruction_cache
+flush_instruction_cache:
mflr r6
bl flush_data_cache
@@ -279,7 +280,8 @@ _GLOBAL(flush_instruction_cache)
* Flush data cache
* Do this by just reading lots of stuff into the cache.
*/
-_GLOBAL(flush_data_cache)
+ .globl flush_data_cache
+flush_data_cache:
lis r3,cache_flush_buffer at h
ori r3,r3,cache_flush_buffer at l
li r4,NUM_CACHE_LINES
-- Paul
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