[082/200] powerpc/fsl-booke: Move loadcam_entry back to asm code to fix SMP ftrace

Greg KH
2010-07-01T21:50:12Z

2.6.34-stable review patch. If anyone has any objections, please let me know.

------------------

From: Kumar Gala <galak@kernel.crashing.org>

commit 78f622377f7d31d988db350a43c5689dd5f31876 upstream.

When we build with ftrace enabled its possible that loadcam_entry would
have used the stack pointer (even though the code doesn't need it). We
call loadcam_entry in __secondary_start before the stack is setup. To
ensure that loadcam_entry doesn't use the stack pointer the easiest
solution is to just have it in asm code.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
arch/powerpc/kernel/asm-offsets.c | 8 ++++++++
arch/powerpc/mm/fsl_booke_mmu.c | 25 +++----------------------
arch/powerpc/mm/mmu_decl.h | 8 ++++++++
arch/powerpc/mm/tlb_nohash_low.S | 28 ++++++++++++++++++++++++++++
4 files changed, 47 insertions(+), 22 deletions(-)

--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -447,6 +447,14 @@ int main(void)
DEFINE(PGD_T_LOG2, PGD_T_LOG2);
DEFINE(PTE_T_LOG2, PTE_T_LOG2);
#endif
+#ifdef CONFIG_FSL_BOOKE
+ DEFINE(TLBCAM_SIZE, sizeof(struct tlbcam));
+ DEFINE(TLBCAM_MAS0, offsetof(struct tlbcam, MAS0));
+ DEFINE(TLBCAM_MAS1, offsetof(struct tlbcam, MAS1));
+ DEFINE(TLBCAM_MAS2, offsetof(struct tlbcam, MAS2));
+ DEFINE(TLBCAM_MAS3, offsetof(struct tlbcam, MAS3));
+ DEFINE(TLBCAM_MAS7, offsetof(struct tlbcam, MAS7));
+#endif

#ifdef CONFIG_KVM_EXIT_TIMING
DEFINE(VCPU_TIMING_EXIT_TBU, offsetof(struct kvm_vcpu,
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -2,7 +2,7 @@
* Modifications by Kumar Gala (galak@kernel.crashing.org) to support
* E500 Book E processors.
*
- * Copyright 2004 Freescale Semiconductor, Inc
+ * Copyright 2004,2010 Freescale Semiconductor, Inc.
*
* This file contains the routines for initializing the MMU
* on the 4xx series of chips.
@@ -56,19 +56,13 @@

unsigned int tlbcam_index;

-#define NUM_TLBCAMS (64)

#if defined(CONFIG_LOWMEM_CAM_NUM_BOOL) && (CONFIG_LOWMEM_CAM_NUM >= NUM_TLBCAMS)
#error "LOWMEM_CAM_NUM must be less than NUM_TLBCAMS"
#endif

-struct tlbcam {
- u32 MAS0;
- u32 MAS1;
- unsigned long MAS2;
- u32 MAS3;
- u32 MAS7;
-} TLBCAM[NUM_TLBCAMS];
+#define NUM_TLBCAMS (64)
+struct tlbcam TLBCAM[NUM_TLBCAMS];

struct tlbcamrange {
unsigned long start;
@@ -109,19 +103,6 @@ unsigned long p_mapped_by_tlbcam(phys_ad
return 0;
}

-void loadcam_entry(int idx)
-{
- mtspr(SPRN_MAS0, TLBCAM[idx].MAS0);
- mtspr(SPRN_MAS1, TLBCAM[idx].MAS1);
- mtspr(SPRN_MAS2, TLBCAM[idx].MAS2);
- mtspr(SPRN_MAS3, TLBCAM[idx].MAS3);
-
- if (mmu_has_feature(MMU_FTR_BIG_PHYS))
- mtspr(SPRN_MAS7, TLBCAM[idx].MAS7);
-
- asm volatile("isync;tlbwe;isync" : : : "memory");
-}
-
/*
* Set up one of the I/D BAT (block address translation) register pairs.
* The parameters are not checked; in particular size must be a power
--- a/arch/powerpc/mm/mmu_decl.h
+++ b/arch/powerpc/mm/mmu_decl.h
@@ -149,7 +149,15 @@ extern unsigned long mmu_mapin_ram(unsig
extern void MMU_init_hw(void);
extern unsigned long mmu_mapin_ram(unsigned long top);
extern void adjust_total_lowmem(void);
+extern void loadcam_entry(unsigned int index);

+struct tlbcam {
+ u32 MAS0;
+ u32 MAS1;
+ unsigned long MAS2;
+ u32 MAS3;
+ u32 MAS7;
+};
#elif defined(CONFIG_PPC32)
/* anything 32-bit except 4xx or 8xx */
extern void MMU_init_hw(void);
--- a/arch/powerpc/mm/tlb_nohash_low.S
+++ b/arch/powerpc/mm/tlb_nohash_low.S
@@ -271,3 +271,31 @@ _GLOBAL(set_context)
#else
#error Unsupported processor type !
#endif
+
+#if defined(CONFIG_FSL_BOOKE)
+/*
+ * extern void loadcam_entry(unsigned int index)
+ *
+ * Load TLBCAM[index] entry in to the L2 CAM MMU
+ */
+_GLOBAL(loadcam_entry)
+ LOAD_REG_ADDR(r4, TLBCAM)
+ mulli r5,r3,TLBCAM_SIZE
+ add r3,r5,r4
+ lwz r4,TLBCAM_MAS0(r3)
+ mtspr SPRN_MAS0,r4
+ lwz r4,TLBCAM_MAS1(r3)
+ mtspr SPRN_MAS1,r4
+ PPC_LL r4,TLBCAM_MAS2(r3)
+ mtspr SPRN_MAS2,r4
+ lwz r4,TLBCAM_MAS3(r3)
+ mtspr SPRN_MAS3,r4
+BEGIN_MMU_FTR_SECTION
+ lwz r4,TLBCAM_MAS7(r3)
+ mtspr SPRN_MAS7,r4
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_BIG_PHYS)
+ isync
+ tlbwe
+ isync
+ blr
+#endif