diff options
Diffstat (limited to 'arch/powerpc/mm/slb.c')
| -rw-r--r-- | arch/powerpc/mm/slb.c | 108 |
1 files changed, 108 insertions, 0 deletions
diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c index 13cfe413b40d..66577cc66dc9 100644 --- a/arch/powerpc/mm/slb.c +++ b/arch/powerpc/mm/slb.c @@ -22,6 +22,7 @@ #include <asm/cacheflush.h> #include <asm/smp.h> #include <linux/compiler.h> +#include <linux/context_tracking.h> #include <linux/mm_types.h> #include <asm/udbg.h> @@ -340,3 +341,110 @@ void slb_initialize(void) asm volatile("isync":::"memory"); } + +static void insert_slb_entry(unsigned long vsid, unsigned long ea, + int bpsize, int ssize) +{ + unsigned long flags, vsid_data, esid_data; + enum slb_index index; + int slb_cache_index; + + /* + * We are irq disabled, hence should be safe to access PACA. + */ + index = get_paca()->stab_rr; + + /* + * simple round-robin replacement of slb starting at SLB_NUM_BOLTED. + */ + if (index < (mmu_slb_size - 1)) + index++; + else + index = SLB_NUM_BOLTED; + + get_paca()->stab_rr = index; + + flags = SLB_VSID_USER | mmu_psize_defs[bpsize].sllp; + vsid_data = (vsid << slb_vsid_shift(ssize)) | flags | + ((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT); + esid_data = mk_esid_data(ea, ssize, index); + + asm volatile("slbmte %0, %1" : : "r" (vsid_data), "r" (esid_data) + : "memory"); + + /* + * Now update slb cache entries + */ + slb_cache_index = get_paca()->slb_cache_ptr; + if (slb_cache_index < SLB_CACHE_ENTRIES) { + /* + * We have space in slb cache for optimized switch_slb(). + * Top 36 bits from esid_data as per ISA + */ + get_paca()->slb_cache[slb_cache_index++] = esid_data >> 28; + get_paca()->slb_cache_ptr++; + } else { + /* + * Our cache is full and the current cache content strictly + * doesn't indicate the active SLB conents. Bump the ptr + * so that switch_slb() will ignore the cache. + */ + get_paca()->slb_cache_ptr = SLB_CACHE_ENTRIES + 1; + } +} + +static void handle_multi_context_slb_miss(int context_id, unsigned long ea) +{ + struct mm_struct *mm = current->mm; + unsigned long vsid; + int bpsize; + + /* + * We are always above 1TB, hence use high user segment size. + */ + vsid = get_vsid(context_id, ea, mmu_highuser_ssize); + bpsize = get_slice_psize(mm, ea); + insert_slb_entry(vsid, ea, bpsize, mmu_highuser_ssize); +} + +void slb_miss_large_addr(struct pt_regs *regs) +{ + enum ctx_state prev_state = exception_enter(); + unsigned long ea = regs->dar; + int context; + + if (REGION_ID(ea) != USER_REGION_ID) + goto slb_bad_addr; + + /* + * Are we beyound what the page table layout supports ? + */ + if ((ea & ~REGION_MASK) >= H_PGTABLE_RANGE) + goto slb_bad_addr; + + /* Lower address should have been handled by asm code */ + if (ea < (1UL << MAX_EA_BITS_PER_CONTEXT)) + goto slb_bad_addr; + + /* + * consider this as bad access if we take a SLB miss + * on an address above addr limit. + */ + if (ea >= current->mm->context.slb_addr_limit) + goto slb_bad_addr; + + context = get_ea_context(¤t->mm->context, ea); + if (!context) + goto slb_bad_addr; + + handle_multi_context_slb_miss(context, ea); + exception_exit(prev_state); + return; + +slb_bad_addr: + if (user_mode(regs)) + _exception(SIGSEGV, regs, SEGV_BNDERR, ea); + else + bad_page_fault(regs, ea, SIGSEGV); + exception_exit(prev_state); +} |