Merge git://git.infradead.org/battery-2.6

[linux-2.6-omap-h63xx.git] / arch / powerpc / mm / hash_low_32.S

diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S
index bd68df5fa78ac083bc0479946b1085c44934f5b7..7f830a4888d6e6bc66488ec2b7da02250174c798 100644 (file)
--- a/arch/powerpc/mm/hash_low_32.S
+++ b/arch/powerpc/mm/hash_low_32.S
@@ -30,7 +30,11 @@
 #include <asm/asm-offsets.h>
 
 #ifdef CONFIG_SMP
-       .comm   mmu_hash_lock,4
+       .section .bss
+       .align  2
+       .globl mmu_hash_lock
+mmu_hash_lock:
+       .space  4
 #endif /* CONFIG_SMP */
 
 /*
@@ -283,6 +287,7 @@ 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 +394,30 @@ _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 */
@@ -437,9 +459,15 @@ found_slot:
        sync            /* make sure pte updates get to memory */
        blr
 
-       .comm   next_slot,4
-       .comm   primary_pteg_full,4
-       .comm   htab_hash_searches,4
+       .section .bss
+       .align  2
+next_slot:
+       .space  4
+primary_pteg_full:
+       .space  4
+htab_hash_searches:
+       .space  4
+       .previous
 
 /*
  * Flush the entry for a particular page from the hash table.