diff options
Diffstat (limited to 'arch/powerpc/mm/slb.c')
| -rw-r--r-- | arch/powerpc/mm/slb.c | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c index 6e450ca66526..8a32a2be3c53 100644 --- a/arch/powerpc/mm/slb.c +++ b/arch/powerpc/mm/slb.c @@ -41,9 +41,9 @@ static void slb_allocate(unsigned long ea) (((ssize) == MMU_SEGSIZE_256M)? ESID_MASK: ESID_MASK_1T) static inline unsigned long mk_esid_data(unsigned long ea, int ssize, - unsigned long slot) + unsigned long entry) { - return (ea & slb_esid_mask(ssize)) | SLB_ESID_V | slot; + return (ea & slb_esid_mask(ssize)) | SLB_ESID_V | entry; } static inline unsigned long mk_vsid_data(unsigned long ea, int ssize, @@ -249,11 +249,24 @@ void switch_slb(struct task_struct *tsk, struct mm_struct *mm) static inline void patch_slb_encoding(unsigned int *insn_addr, unsigned int immed) { - int insn = (*insn_addr & 0xffff0000) | immed; + + /* + * This function patches either an li or a cmpldi instruction with + * a new immediate value. This relies on the fact that both li + * (which is actually addi) and cmpldi both take a 16-bit immediate + * value, and it is situated in the same location in the instruction, + * ie. bits 16-31 (Big endian bit order) or the lower 16 bits. + * The signedness of the immediate operand differs between the two + * instructions however this code is only ever patching a small value, + * much less than 1 << 15, so we can get away with it. + * To patch the value we read the existing instruction, clear the + * immediate value, and or in our new value, then write the instruction + * back. + */ + unsigned int insn = (*insn_addr & 0xffff0000) | immed; patch_instruction(insn_addr, insn); } -extern u32 slb_compare_rr_to_size[]; extern u32 slb_miss_kernel_load_linear[]; extern u32 slb_miss_kernel_load_io[]; extern u32 slb_compare_rr_to_size[]; @@ -309,12 +322,11 @@ void slb_initialize(void) lflags = SLB_VSID_KERNEL | linear_llp; vflags = SLB_VSID_KERNEL | vmalloc_llp; - /* Invalidate the entire SLB (even slot 0) & all the ERATS */ + /* Invalidate the entire SLB (even entry 0) & all the ERATS */ asm volatile("isync":::"memory"); asm volatile("slbmte %0,%0"::"r" (0) : "memory"); asm volatile("isync; slbia; isync":::"memory"); create_shadowed_slbe(PAGE_OFFSET, mmu_kernel_ssize, lflags, 0); - create_shadowed_slbe(VMALLOC_START, mmu_kernel_ssize, vflags, 1); /* For the boot cpu, we're running on the stack in init_thread_union, |