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powerpc/fsl-booke: Fixup 64-bit PTE reading for SMP support
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We need to create a false data dependency to ensure the loads of
the pte are done in the right order.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
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Kumar Gala committed Sep 19, 2008
1 parent 33a7f12 commit b38fd42
Showing 1 changed file with 21 additions and 5 deletions.
26 changes: 21 additions & 5 deletions arch/powerpc/kernel/head_fsl_booke.S
Original file line number Diff line number Diff line change
Expand Up @@ -579,13 +579,19 @@ interrupt_base:

FIND_PTE
andc. r13,r13,r11 /* Check permission */
bne 2f /* Bail if permission mismach */

#ifdef CONFIG_PTE_64BIT
lwz r13, 0(r12)
#ifdef CONFIG_SMP
subf r10,r11,r12 /* create false data dep */
lwzx r13,r11,r10 /* Get upper pte bits */
#else
lwz r13,0(r12) /* Get upper pte bits */
#endif
#endif

/* Jump to common tlb load */
bne 2f /* Bail if permission/valid mismach */

/* Jump to common tlb load */
b finish_tlb_load
2:
/* The bailout. Restore registers to pre-exception conditions
Expand Down Expand Up @@ -640,10 +646,20 @@ interrupt_base:

FIND_PTE
andc. r13,r13,r11 /* Check permission */

#ifdef CONFIG_PTE_64BIT
#ifdef CONFIG_SMP
subf r10,r11,r12 /* create false data dep */
lwzx r13,r11,r10 /* Get upper pte bits */
#else
lwz r13,0(r12) /* Get upper pte bits */
#endif
#endif

bne 2f /* Bail if permission mismach */

#ifdef CONFIG_PTE_64BIT
lwz r13, 0(r12)
lwz r13,0(r12)
#endif

/* Jump to common TLB load point */
Expand Down Expand Up @@ -702,7 +718,7 @@ interrupt_base:
/*
* Both the instruction and data TLB miss get to this
* point to load the TLB.
* r10 - EA of fault
* r10 - available to use
* r11 - TLB (info from Linux PTE)
* r12 - available to use
* r13 - upper bits of PTE (if PTE_64BIT) or available to use
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