diff options
Diffstat (limited to 'arch/powerpc/mm/hash_low_32.S')
| -rw-r--r-- | arch/powerpc/mm/hash_low_32.S | 22 |
1 files changed, 20 insertions, 2 deletions
diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S index bd68df5fa78a..ddceefc06ecc 100644 --- a/arch/powerpc/mm/hash_low_32.S +++ b/arch/powerpc/mm/hash_low_32.S @@ -283,6 +283,7 @@ Hash_msk = (((1 << Hash_bits) - 1) * 64) #define PTEG_SIZE 64 #define LG_PTEG_SIZE 6 #define LDPTEu lwzu +#define LDPTE lwz #define STPTE stw #define CMPPTE cmpw #define PTE_H 0x40 @@ -389,13 +390,30 @@ _GLOBAL(hash_page_patch_C) * and we know there is a definite (although small) speed * advantage to putting the PTE in the primary PTEG, we always * put the PTE in the primary PTEG. + * + * In addition, we skip any slot that is mapping kernel text in + * order to avoid a deadlock when not using BAT mappings if + * trying to hash in the kernel hash code itself after it has + * already taken the hash table lock. This works in conjunction + * with pre-faulting of the kernel text. + * + * If the hash table bucket is full of kernel text entries, we'll + * lockup here but that shouldn't happen */ - addis r4,r7,next_slot@ha + +1: addis r4,r7,next_slot@ha /* get next evict slot */ lwz r6,next_slot@l(r4) - addi r6,r6,PTE_SIZE + addi r6,r6,PTE_SIZE /* search for candidate */ andi. r6,r6,7*PTE_SIZE stw r6,next_slot@l(r4) add r4,r3,r6 + LDPTE r0,PTE_SIZE/2(r4) /* get PTE second word */ + clrrwi r0,r0,12 + lis r6,etext@h + ori r6,r6,etext@l /* get etext */ + tophys(r6,r6) + cmpl cr0,r0,r6 /* compare and try again */ + blt 1b #ifndef CONFIG_SMP /* Store PTE in PTEG */ |