diff options
| author | Scott Wood <scottwood@freescale.com> | 2015-04-03 06:14:11 +0300 |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2015-06-03 05:37:19 +0300 |
| commit | c89ca8ab7457d891abdffca7e6f5e74cef670d6d (patch) | |
| tree | 18ac7b62e33d0b8c640ca3ea06404be150fa75e7 /arch/powerpc/mm | |
| parent | fb326e9841b2000a8d1b115ccd7f5b3b61a4d123 (diff) | |
| download | linux-c89ca8ab7457d891abdffca7e6f5e74cef670d6d.tar.xz | |
powerpc/e6500: Optimize hugepage TLB misses
Some workloads take a lot of TLB misses despite using traditional
hugepages. Handle these TLB misses in the asm fastpath rather than
going through a bunch of C code. With this patch I measured around a
5x speedup in handling hugepage TLB misses.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Diffstat (limited to 'arch/powerpc/mm')
| -rw-r--r-- | arch/powerpc/mm/tlb_low_64e.S | 51 |
1 files changed, 48 insertions, 3 deletions
diff --git a/arch/powerpc/mm/tlb_low_64e.S b/arch/powerpc/mm/tlb_low_64e.S index 89bf95bd63b1..765b419883f2 100644 --- a/arch/powerpc/mm/tlb_low_64e.S +++ b/arch/powerpc/mm/tlb_low_64e.S @@ -398,18 +398,18 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_SMT) rldicl r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3 clrrdi r15,r15,3 cmpdi cr0,r14,0 - bge tlb_miss_fault_e6500 /* Bad pgd entry or hugepage; bail */ + bge tlb_miss_huge_e6500 /* Bad pgd entry or hugepage; bail */ ldx r14,r14,r15 /* grab pud entry */ rldicl r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3 clrrdi r15,r15,3 cmpdi cr0,r14,0 - bge tlb_miss_fault_e6500 + bge tlb_miss_huge_e6500 ldx r14,r14,r15 /* Grab pmd entry */ mfspr r10,SPRN_MAS0 cmpdi cr0,r14,0 - bge tlb_miss_fault_e6500 + bge tlb_miss_huge_e6500 /* Now we build the MAS for a 2M indirect page: * @@ -428,6 +428,7 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_SMT) clrrdi r15,r16,21 /* make EA 2M-aligned */ mtspr SPRN_MAS2,r15 +tlb_miss_huge_done_e6500: lbz r15,TCD_ESEL_NEXT(r11) lbz r16,TCD_ESEL_MAX(r11) lbz r14,TCD_ESEL_FIRST(r11) @@ -456,6 +457,50 @@ END_FTR_SECTION_IFSET(CPU_FTR_SMT) tlb_epilog_bolted rfi +tlb_miss_huge_e6500: + beq tlb_miss_fault_e6500 + li r10,1 + andi. r15,r14,HUGEPD_SHIFT_MASK@l /* r15 = psize */ + rldimi r14,r10,63,0 /* Set PD_HUGE */ + xor r14,r14,r15 /* Clear size bits */ + ldx r14,0,r14 + + /* + * Now we build the MAS for a huge page. + * + * MAS 0 : ESEL needs to be filled by software round-robin + * - can be handled by indirect code + * MAS 1 : Need to clear IND and set TSIZE + * MAS 2,3+7: Needs to be redone similar to non-tablewalk handler + */ + + subi r15,r15,10 /* Convert psize to tsize */ + mfspr r10,SPRN_MAS1 + rlwinm r10,r10,0,~MAS1_IND + rlwimi r10,r15,MAS1_TSIZE_SHIFT,MAS1_TSIZE_MASK + mtspr SPRN_MAS1,r10 + + li r10,-0x400 + sld r15,r10,r15 /* Generate mask based on size */ + and r10,r16,r15 + rldicr r15,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT + rlwimi r10,r14,32-19,27,31 /* Insert WIMGE */ + clrldi r15,r15,PAGE_SHIFT /* Clear crap at the top */ + rlwimi r15,r14,32-8,22,25 /* Move in U bits */ + mtspr SPRN_MAS2,r10 + andi. r10,r14,_PAGE_DIRTY + rlwimi r15,r14,32-2,26,31 /* Move in BAP bits */ + + /* Mask out SW and UW if !DIRTY (XXX optimize this !) */ + bne 1f + li r10,MAS3_SW|MAS3_UW + andc r15,r15,r10 +1: + mtspr SPRN_MAS7_MAS3,r15 + + mfspr r10,SPRN_MAS0 + b tlb_miss_huge_done_e6500 + tlb_miss_kernel_e6500: ld r14,PACA_KERNELPGD(r13) cmpldi cr1,r15,8 /* Check for vmalloc region */ |