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authorVladimir Serbinenko <phcoder@gmail.com>2013-11-26 17:49:29 +0100
committerStefan Reinauer <stefan.reinauer@coreboot.org>2013-12-02 20:10:38 +0100
commita6c29fe6841ad5e03ddb35803943bed3bc83dfd2 (patch)
tree8d1250b77c57e4e0020cb2b027e8c395e0fa462b /src
parent77a5abe78052ac8f65c005272700d82c2b014da7 (diff)
amd/car/post_cache_as_ram: Switch stack in assembly rather than in C
Compiler may do loads of optimisations around stack switch and so it's allowed to break stack switch as it sees fit. Do it in assembly instead. Not tested. Change-Id: I277a62a9052e8fe9b04e7c65d149e087282ac2a2 Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com> Reviewed-on: http://review.coreboot.org/4286 Tested-by: build bot (Jenkins) Reviewed-by: Zheng Bao <zheng.bao@amd.com> Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'src')
-rw-r--r--src/cpu/amd/car/cache_as_ram.inc12
-rw-r--r--src/cpu/amd/car/post_cache_as_ram.c25
2 files changed, 22 insertions, 15 deletions
diff --git a/src/cpu/amd/car/cache_as_ram.inc b/src/cpu/amd/car/cache_as_ram.inc
index 7070cf9b10..8f0abce1a5 100644
--- a/src/cpu/amd/car/cache_as_ram.inc
+++ b/src/cpu/amd/car/cache_as_ram.inc
@@ -414,10 +414,22 @@ CAR_FAM10_ap_out:
pushl %ebx /* Init detected. */
pushl %eax /* BIST */
call cache_as_ram_main
+
/* We will not go back. */
post_code(0xaf) /* Should never see this POST code. */
+ .globl cache_as_ram_switch_stack
+
+cache_as_ram_switch_stack:
+ /* Return address. */
+ popl %eax
+ /* Resume memory. */
+ popl %eax
+ subl $(( (CONFIG_DCACHE_RAM_BASE + CONFIG_DCACHE_RAM_SIZE)- (CONFIG_RAMTOP) )), %esp
+ pushl %eax
+ call cache_as_ram_new_stack
+
all_mtrr_msrs:
/* fixed MTRR MSRs */
.long MTRRfix64K_00000_MSR
diff --git a/src/cpu/amd/car/post_cache_as_ram.c b/src/cpu/amd/car/post_cache_as_ram.c
index eca7673df3..3fe496e44c 100644
--- a/src/cpu/amd/car/post_cache_as_ram.c
+++ b/src/cpu/amd/car/post_cache_as_ram.c
@@ -75,11 +75,11 @@ static void vErrata343(void)
#endif
}
+void cache_as_ram_switch_stack(void *resume_backup_memory);
+
static void post_cache_as_ram(void)
{
-#if CONFIG_HAVE_ACPI_RESUME
- void *resume_backup_memory;
-#endif
+ void *resume_backup_memory = NULL;
#if 1
{
/* Check value of esp to verify if we have enough room for stack in Cache as RAM */
@@ -92,9 +92,6 @@ static void post_cache_as_ram(void)
}
#endif
- unsigned testx = 0x5a5a5a5a;
- print_debug_pcar("testx = ", testx);
-
/* copy data from cache as ram to
ram need to set CONFIG_RAMTOP to 2M and use var mtrr instead.
*/
@@ -112,21 +109,19 @@ static void post_cache_as_ram(void)
vErrata343();
memcopy((void *)((CONFIG_RAMTOP)-CONFIG_DCACHE_RAM_SIZE), (void *)CONFIG_DCACHE_RAM_BASE, CONFIG_DCACHE_RAM_SIZE); //inline
+ cache_as_ram_switch_stack(resume_backup_memory);
+}
- __asm__ volatile (
- /* set new esp */ /* before CONFIG_RAMBASE */
- "subl %0, %%esp\n\t"
- ::"a"( (CONFIG_DCACHE_RAM_BASE + CONFIG_DCACHE_RAM_SIZE)- (CONFIG_RAMTOP) )
- /* discard all registers (eax is used for %0), so gcc redoes everything
- after the stack is moved */
- : "cc", "memory", "%ebx", "%ecx", "%edx", "%esi", "%edi", "%ebp"
- );
+void
+cache_as_ram_new_stack (void *resume_backup_memory);
+void
+cache_as_ram_new_stack (void *resume_backup_memory __attribute__ ((unused)))
+{
/* We can put data to stack again */
/* only global variable sysinfo in cache need to be offset */
print_debug("Done\n");
- print_debug_pcar("testx = ", testx);
print_debug("Disabling cache as ram now \n");