From 2a7e2990340a1c42321d79dc99755683ea5a1026 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Wed, 21 Sep 2005 18:50:51 -0700 Subject: [SPARC64]: Move kernel TLB miss handling into a seperate file. Signed-off-by: David S. Miller --- arch/sparc64/kernel/ktlb.S | 174 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 174 insertions(+) create mode 100644 arch/sparc64/kernel/ktlb.S (limited to 'arch/sparc64/kernel/ktlb.S') diff --git a/arch/sparc64/kernel/ktlb.S b/arch/sparc64/kernel/ktlb.S new file mode 100644 index 00000000000..b7176792c9a --- /dev/null +++ b/arch/sparc64/kernel/ktlb.S @@ -0,0 +1,174 @@ +/* arch/sparc64/kernel/ktlb.S: Kernel mapping TLB miss handling. + * + * Copyright (C) 1995, 1997, 2005 David S. Miller + * Copyright (C) 1996 Eddie C. Dost (ecd@brainaid.de) + * Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx) + * Copyright (C) 1996,98,99 Jakub Jelinek (jj@sunsite.mff.cuni.cz) +*/ + +#include +#include +#include +#include +#include + + .text + .align 32 + + .globl sparc64_vpte_patchme1 + .globl sparc64_vpte_patchme2 +/* + * On a second level vpte miss, check whether the original fault is to the OBP + * range (note that this is only possible for instruction miss, data misses to + * obp range do not use vpte). If so, go back directly to the faulting address. + * This is because we want to read the tpc, otherwise we have no way of knowing + * the 8k aligned faulting address if we are using >8k kernel pagesize. This + * also ensures no vpte range addresses are dropped into tlb while obp is + * executing (see inherit_locked_prom_mappings() rant). + */ +sparc64_vpte_nucleus: + /* Note that kvmap below has verified that the address is + * in the range MODULES_VADDR --> VMALLOC_END already. So + * here we need only check if it is an OBP address or not. + */ + sethi %hi(LOW_OBP_ADDRESS), %g5 + cmp %g4, %g5 + blu,pn %xcc, sparc64_vpte_patchme1 + mov 0x1, %g5 + sllx %g5, 32, %g5 + cmp %g4, %g5 + blu,pn %xcc, obp_iaddr_patch + nop + + /* These two instructions are patched by paginig_init(). */ +sparc64_vpte_patchme1: + sethi %hi(0), %g5 +sparc64_vpte_patchme2: + or %g5, %lo(0), %g5 + + /* With kernel PGD in %g5, branch back into dtlb_backend. */ + ba,pt %xcc, sparc64_kpte_continue + andn %g1, 0x3, %g1 /* Finish PMD offset adjustment. */ + +vpte_noent: + /* Restore previous TAG_ACCESS, %g5 is zero, and we will + * skip over the trap instruction so that the top level + * TLB miss handler will thing this %g5 value is just an + * invalid PTE, thus branching to full fault processing. + */ + mov TLB_SFSR, %g1 + stxa %g4, [%g1 + %g1] ASI_DMMU + done + + .globl obp_iaddr_patch +obp_iaddr_patch: + /* These two instructions patched by inherit_prom_mappings(). */ + sethi %hi(0), %g5 + or %g5, %lo(0), %g5 + + /* Behave as if we are at TL0. */ + wrpr %g0, 1, %tl + rdpr %tpc, %g4 /* Find original faulting iaddr */ + srlx %g4, 13, %g4 /* Throw out context bits */ + sllx %g4, 13, %g4 /* g4 has vpn + ctx0 now */ + + /* Restore previous TAG_ACCESS. */ + mov TLB_SFSR, %g1 + stxa %g4, [%g1 + %g1] ASI_IMMU + + /* Get PMD offset. */ + srlx %g4, 23, %g6 + and %g6, 0x7ff, %g6 + sllx %g6, 2, %g6 + + /* Load PMD, is it valid? */ + lduwa [%g5 + %g6] ASI_PHYS_USE_EC, %g5 + brz,pn %g5, longpath + sllx %g5, 11, %g5 + + /* Get PTE offset. */ + srlx %g4, 13, %g6 + and %g6, 0x3ff, %g6 + sllx %g6, 3, %g6 + + /* Load PTE. */ + ldxa [%g5 + %g6] ASI_PHYS_USE_EC, %g5 + brgez,pn %g5, longpath + nop + + /* TLB load and return from trap. */ + stxa %g5, [%g0] ASI_ITLB_DATA_IN + retry + + .globl obp_daddr_patch +obp_daddr_patch: + /* These two instructions patched by inherit_prom_mappings(). */ + sethi %hi(0), %g5 + or %g5, %lo(0), %g5 + + /* Get PMD offset. */ + srlx %g4, 23, %g6 + and %g6, 0x7ff, %g6 + sllx %g6, 2, %g6 + + /* Load PMD, is it valid? */ + lduwa [%g5 + %g6] ASI_PHYS_USE_EC, %g5 + brz,pn %g5, longpath + sllx %g5, 11, %g5 + + /* Get PTE offset. */ + srlx %g4, 13, %g6 + and %g6, 0x3ff, %g6 + sllx %g6, 3, %g6 + + /* Load PTE. */ + ldxa [%g5 + %g6] ASI_PHYS_USE_EC, %g5 + brgez,pn %g5, longpath + nop + + /* TLB load and return from trap. */ + stxa %g5, [%g0] ASI_DTLB_DATA_IN + retry + +/* + * On a first level data miss, check whether this is to the OBP range (note + * that such accesses can be made by prom, as well as by kernel using + * prom_getproperty on "address"), and if so, do not use vpte access ... + * rather, use information saved during inherit_prom_mappings() using 8k + * pagesize. + */ + .align 32 +kvmap: + brlz,pt %g4, kvmap_load + xor %g2, %g4, %g5 + +kvmap_nonlinear: + sethi %hi(MODULES_VADDR), %g5 + cmp %g4, %g5 + blu,pn %xcc, longpath + mov (VMALLOC_END >> 24), %g5 + sllx %g5, 24, %g5 + cmp %g4, %g5 + bgeu,pn %xcc, longpath + nop + +kvmap_check_obp: + sethi %hi(LOW_OBP_ADDRESS), %g5 + cmp %g4, %g5 + blu,pn %xcc, kvmap_vmalloc_addr + mov 0x1, %g5 + sllx %g5, 32, %g5 + cmp %g4, %g5 + blu,pn %xcc, obp_daddr_patch + nop + +kvmap_vmalloc_addr: + /* If we get here, a vmalloc addr was accessed, load kernel VPTE. */ + ldxa [%g3 + %g6] ASI_N, %g5 + brgez,pn %g5, longpath + nop + +kvmap_load: + /* PTE is valid, load into TLB and return from trap. */ + stxa %g5, [%g0] ASI_DTLB_DATA_IN ! Reload TLB + retry -- cgit v1.2.3