diff options
| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-05-03 14:07:01 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-05-06 13:32:24 +1000 |
| commit | 40bd587a88fcd425f489f3d9f0be7daa84014141 (patch) | |
| tree | 3d6d977fc23cae661ee358b1ad8611ed11611d03 /arch/powerpc | |
| parent | 77eafe101a65b609b0693ee4eda381f60a4a5bab (diff) | |
powerpc: Rename slb0_limit() to safe_stack_limit() and add Book3E support
slb0_limit() wasn't a very descriptive name. This changes it along with
a comment explaining what it's used for, and provides a 64-bit BookE
implementation.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/include/asm/mmu-book3e.h | 4 | ||||
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 23 |
2 files changed, 22 insertions, 5 deletions
diff --git a/arch/powerpc/include/asm/mmu-book3e.h b/arch/powerpc/include/asm/mmu-book3e.h index ec61e7b998c0..3ea0f9a259d8 100644 --- a/arch/powerpc/include/asm/mmu-book3e.h +++ b/arch/powerpc/include/asm/mmu-book3e.h @@ -245,6 +245,10 @@ extern struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT]; extern int mmu_linear_psize; extern int mmu_vmemmap_psize; +#ifdef CONFIG_PPC64 +extern unsigned long linear_map_top; +#endif + #endif /* !__ASSEMBLY__ */ #endif /* _ASM_POWERPC_MMU_BOOK3E_H_ */ diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index 959c63cf62e4..c2ec0a12e14f 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -434,17 +434,30 @@ void __init setup_system(void) DBG(" <- setup_system()\n"); } -static u64 slb0_limit(void) +/* This returns the limit below which memory accesses to the linear + * mapping are guarnateed not to cause a TLB or SLB miss. This is + * used to allocate interrupt or emergency stacks for which our + * exception entry path doesn't deal with being interrupted. + */ +static u64 safe_stack_limit(void) { - if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) { +#ifdef CONFIG_PPC_BOOK3E + /* Freescale BookE bolts the entire linear mapping */ + if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) + return linear_map_top; + /* Other BookE, we assume the first GB is bolted */ + return 1ul << 30; +#else + /* BookS, the first segment is bolted */ + if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) return 1UL << SID_SHIFT_1T; - } return 1UL << SID_SHIFT; +#endif } static void __init irqstack_early_init(void) { - u64 limit = slb0_limit(); + u64 limit = safe_stack_limit(); unsigned int i; /* @@ -497,7 +510,7 @@ static void __init emergency_stack_init(void) * bringup, we need to get at them in real mode. This means they * must also be within the RMO region. */ - limit = min(slb0_limit(), ppc64_rma_size); + limit = min(safe_stack_limit(), ppc64_rma_size); for_each_possible_cpu(i) { unsigned long sp; |