From: David S. Miller Date: Sat, 11 Feb 2006 08:29:34 +0000 (-0800) Subject: [SPARC64]: Simplify sun4v TLB handling using macros. X-Git-Tag: v2.6.17-rc1~1184^2~157 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=36a68e77c554f1ef1c206fd618e6daf82d3e38a3;p=linux-2.6 [SPARC64]: Simplify sun4v TLB handling using macros. There was also a bug in sun4v_itlb_miss, it loaded the MMU Fault Status base into %g3 instead of %g2. This pointed out a fast path for TSB miss processing, since we have %g2 with the MMU Fault Status base, we can use that to quickly load up the PGD phys address. Signed-off-by: David S. Miller --- diff --git a/arch/sparc64/kernel/sun4v_tlb_miss.S b/arch/sparc64/kernel/sun4v_tlb_miss.S index f6222623de..f7129137f9 100644 --- a/arch/sparc64/kernel/sun4v_tlb_miss.S +++ b/arch/sparc64/kernel/sun4v_tlb_miss.S @@ -6,48 +6,55 @@ .text .align 32 -sun4v_itlb_miss: - /* Load MMU Miss base into %g2. */ - ldxa [%g0] ASI_SCRATCHPAD, %g3 - - /* Load UTSB reg into %g1. */ - mov SCRATCHPAD_UTSBREG1, %g1 - ldxa [%g1] ASI_SCRATCHPAD, %g1 + /* Load ITLB fault information into VADDR and CTX, using BASE. */ +#define LOAD_ITLB_INFO(BASE, VADDR, CTX) \ + ldx [BASE + HV_FAULT_I_ADDR_OFFSET], VADDR; \ + ldx [BASE + HV_FAULT_I_CTX_OFFSET], CTX; + + /* Load DTLB fault information into VADDR and CTX, using BASE. */ +#define LOAD_DTLB_INFO(BASE, VADDR, CTX) \ + ldx [BASE + HV_FAULT_D_ADDR_OFFSET], VADDR; \ + ldx [BASE + HV_FAULT_D_CTX_OFFSET], CTX; - /* Create a TAG TARGET, "(vaddr>>22) | (ctx << 48)", in %g6. - * Branch if kernel TLB miss. The kernel TSB and user TSB miss - * code wants the missing virtual address in %g4, so that value - * cannot be modified through the entirety of this handler. + /* DEST = (CTX << 48) | (VADDR >> 22) + * + * Branch to ZERO_CTX_LABEL is context is zero. */ - ldx [%g2 + HV_FAULT_I_ADDR_OFFSET], %g4 - ldx [%g2 + HV_FAULT_I_CTX_OFFSET], %g5 - srlx %g4, 22, %g3 - sllx %g5, 48, %g6 - or %g6, %g3, %g6 - brz,pn %g5, kvmap_itlb_4v - nop +#define COMPUTE_TAG_TARGET(DEST, VADDR, CTX, TMP, ZERO_CTX_LABEL) \ + srlx VADDR, 22, TMP; \ + sllx CTX, 48, DEST; \ + brz,pn CTX, ZERO_CTX_LABEL; \ + or DEST, TMP, DEST; /* Create TSB pointer. This is something like: * * index_mask = (512 << (tsb_reg & 0x7UL)) - 1UL; * tsb_base = tsb_reg & ~0x7UL; - */ - and %g1, 0x7, %g3 - andn %g1, 0x7, %g1 - mov 512, %g7 - sllx %g7, %g3, %g7 - sub %g7, 1, %g7 - - /* TSB index mask is in %g7, tsb base is in %g1. Compute - * the TSB entry pointer into %g1: - * * tsb_index = ((vaddr >> PAGE_SHIFT) & tsb_mask); * tsb_ptr = tsb_base + (tsb_index * 16); */ - srlx %g4, PAGE_SHIFT, %g3 - and %g3, %g7, %g3 - sllx %g3, 4, %g3 - add %g1, %g3, %g1 +#define COMPUTE_TSB_PTR(TSB_PTR, VADDR, TMP1, TMP2) \ + and TSB_PTR, 0x7, TMP1; \ + mov 512, TMP2; \ + andn TSB_PTR, 0x7, TSB_PTR; \ + sllx TMP2, TMP1, TMP2; \ + srlx VADDR, PAGE_SHIFT, TMP1; \ + sub TMP2, 1, TMP2; \ + and TMP1, TMP2, TMP1; \ + sllx TMP1, 4, TMP1; \ + add TSB_PTR, TMP1, TSB_PTR; + +sun4v_itlb_miss: + /* Load MMU Miss base into %g2. */ + ldxa [%g0] ASI_SCRATCHPAD, %g2 + + /* Load UTSB reg into %g1. */ + mov SCRATCHPAD_UTSBREG1, %g1 + ldxa [%g1] ASI_SCRATCHPAD, %g1 + + LOAD_ITLB_INFO(%g2, %g4, %g5) + COMPUTE_TAG_TARGET(%g6, %g4, %g5, %g3, kvmap_itlb_4v) + COMPUTE_TSB_PTR(%g1, %g4, %g3, %g7) /* Load TSB tag/pte into %g2/%g3 and compare the tag. */ ldda [%g1] ASI_QUAD_LDD_PHYS, %g2 @@ -91,40 +98,9 @@ sun4v_dtlb_miss: mov SCRATCHPAD_UTSBREG1, %g1 ldxa [%g1 + %g1] ASI_SCRATCHPAD, %g1 - /* Create a TAG TARGET, "(vaddr>>22) | (ctx << 48)", in %g6. - * Branch if kernel TLB miss. The kernel TSB and user TSB miss - * code wants the missing virtual address in %g4, so that value - * cannot be modified through the entirety of this handler. - */ - ldx [%g2 + HV_FAULT_D_ADDR_OFFSET], %g4 - ldx [%g2 + HV_FAULT_D_CTX_OFFSET], %g5 - srlx %g4, 22, %g3 - sllx %g5, 48, %g6 - or %g6, %g3, %g6 - brz,pn %g5, kvmap_dtlb_4v - nop - - /* Create TSB pointer. This is something like: - * - * index_mask = (512 << (tsb_reg & 0x7UL)) - 1UL; - * tsb_base = tsb_reg & ~0x7UL; - */ - and %g1, 0x7, %g3 - andn %g1, 0x7, %g1 - mov 512, %g7 - sllx %g7, %g3, %g7 - sub %g7, 1, %g7 - - /* TSB index mask is in %g7, tsb base is in %g1. Compute - * the TSB entry pointer into %g1: - * - * tsb_index = ((vaddr >> PAGE_SHIFT) & tsb_mask); - * tsb_ptr = tsb_base + (tsb_index * 16); - */ - srlx %g4, PAGE_SHIFT, %g3 - and %g3, %g7, %g3 - sllx %g3, 4, %g3 - add %g1, %g3, %g1 + LOAD_DTLB_INFO(%g2, %g4, %g5) + COMPUTE_TAG_TARGET(%g6, %g4, %g5, %g3, kvmap_dtlb_4v) + COMPUTE_TSB_PTR(%g1, %g4, %g3, %g7) /* Load TSB tag/pte into %g2/%g3 and compare the tag. */ ldda [%g1] ASI_QUAD_LDD_PHYS, %g2 @@ -169,7 +145,8 @@ sun4v_dtlb_prot: mov FAULT_CODE_DTLB | FAULT_CODE_WRITE, %g4 /* Called from trap table with TAG TARGET placed into - * %g6 and SCRATCHPAD_UTSBREG1 contents in %g1. + * %g6, SCRATCHPAD_UTSBREG1 contents in %g1, and + * SCRATCHPAD_MMU_MISS contents in %g2. */ sun4v_itsb_miss: ba,pt %xcc, sun4v_tsb_miss_common @@ -189,16 +166,15 @@ sun4v_dtsb_miss: * tsb_ptr = tsb_base + (tsb_index * 16); */ sun4v_tsb_miss_common: - and %g1, 0x7, %g2 - andn %g1, 0x7, %g1 - mov 512, %g7 - sllx %g7, %g2, %g7 - sub %g7, 1, %g7 - srlx %g4, PAGE_SHIFT, %g2 - and %g2, %g7, %g2 - sllx %g2, 4, %g2 - ba,pt %xcc, tsb_miss_page_table_walk - add %g1, %g2, %g1 + COMPUTE_TSB_PTR(%g1, %g4, %g5, %g7) + + /* Branch directly to page table lookup. We have SCRATCHPAD_MMU_MISS + * still in %g2, so it's quite trivial to get at the PGD PHYS value + * so we can preload it into %g7. + */ + sub %g2, TRAP_PER_CPU_FAULT_INFO, %g2 + ba,pt %xcc, tsb_miss_page_table_walk_sun4v_fastpath + ldx [%g2 + TRAP_PER_CPU_PGD_PADDR], %g7 /* Instruction Access Exception, tl0. */ sun4v_iacc: diff --git a/arch/sparc64/kernel/tsb.S b/arch/sparc64/kernel/tsb.S index 8a9351258a..667dcb077b 100644 --- a/arch/sparc64/kernel/tsb.S +++ b/arch/sparc64/kernel/tsb.S @@ -25,26 +25,24 @@ */ tsb_miss_dtlb: mov TLB_TAG_ACCESS, %g4 - ldxa [%g4] ASI_DMMU, %g4 ba,pt %xcc, tsb_miss_page_table_walk - nop + ldxa [%g4] ASI_DMMU, %g4 tsb_miss_itlb: mov TLB_TAG_ACCESS, %g4 - ldxa [%g4] ASI_IMMU, %g4 ba,pt %xcc, tsb_miss_page_table_walk - nop + ldxa [%g4] ASI_IMMU, %g4 - /* The sun4v TLB miss handlers jump directly here instead - * of tsb_miss_{d,i}tlb with registers setup as follows: - * - * %g4: missing virtual address - * %g1: TSB entry address loaded - * %g6: TAG TARGET ((vaddr >> 22) | (ctx << 48)) + /* At this point we have: + * %g4 -- missing virtual address + * %g1 -- TSB entry address + * %g6 -- TAG TARGET ((vaddr >> 22) | (ctx << 48)) */ tsb_miss_page_table_walk: TRAP_LOAD_PGD_PHYS(%g7, %g5) + /* And now we have the PGD base physical address in %g7. */ +tsb_miss_page_table_walk_sun4v_fastpath: USER_PGTABLE_WALK_TL1(%g4, %g7, %g5, %g2, tsb_do_fault) tsb_reload: