diff options
Diffstat (limited to 'arch/sparc64/kernel/ktlb.S')
| -rw-r--r-- | arch/sparc64/kernel/ktlb.S | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/ktlb.S b/arch/sparc64/kernel/ktlb.S new file mode 100644 index 00000000000..d9244d3c9f7 --- /dev/null +++ b/arch/sparc64/kernel/ktlb.S @@ -0,0 +1,194 @@ +/* arch/sparc64/kernel/ktlb.S: Kernel mapping TLB miss handling. + * + * Copyright (C) 1995, 1997, 2005 David S. Miller <davem@davemloft.net> + * 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 <linux/config.h> +#include <asm/head.h> +#include <asm/asi.h> +#include <asm/page.h> +#include <asm/pgtable.h> + + .text + .align 32 + +/* + * 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, kern_vpte + mov 0x1, %g5 + sllx %g5, 32, %g5 + cmp %g4, %g5 + blu,pn %xcc, vpte_insn_obp + nop + + /* These two instructions are patched by paginig_init(). */ +kern_vpte: + sethi %hi(swapper_pgd_zero), %g5 + lduw [%g5 + %lo(swapper_pgd_zero)], %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 + +vpte_insn_obp: + /* 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 + + sethi %hi(prom_trans), %g5 + or %g5, %lo(prom_trans), %g5 + +1: ldx [%g5 + 0x00], %g6 ! base + brz,a,pn %g6, longpath ! no more entries, fail + mov TLB_SFSR, %g1 ! and restore %g1 + ldx [%g5 + 0x08], %g1 ! len + add %g6, %g1, %g1 ! end + cmp %g6, %g4 + bgu,pt %xcc, 2f + cmp %g4, %g1 + bgeu,pt %xcc, 2f + ldx [%g5 + 0x10], %g1 ! PTE + + /* TLB load, restore %g1, and return from trap. */ + sub %g4, %g6, %g6 + add %g1, %g6, %g5 + mov TLB_SFSR, %g1 + stxa %g5, [%g0] ASI_ITLB_DATA_IN + retry + +2: ba,pt %xcc, 1b + add %g5, (3 * 8), %g5 ! next entry + +kvmap_do_obp: + sethi %hi(prom_trans), %g5 + or %g5, %lo(prom_trans), %g5 + srlx %g4, 13, %g4 + sllx %g4, 13, %g4 + +1: ldx [%g5 + 0x00], %g6 ! base + brz,a,pn %g6, longpath ! no more entries, fail + mov TLB_SFSR, %g1 ! and restore %g1 + ldx [%g5 + 0x08], %g1 ! len + add %g6, %g1, %g1 ! end + cmp %g6, %g4 + bgu,pt %xcc, 2f + cmp %g4, %g1 + bgeu,pt %xcc, 2f + ldx [%g5 + 0x10], %g1 ! PTE + + /* TLB load, restore %g1, and return from trap. */ + sub %g4, %g6, %g6 + add %g1, %g6, %g5 + mov TLB_SFSR, %g1 + stxa %g5, [%g0] ASI_DTLB_DATA_IN + retry + +2: ba,pt %xcc, 1b + add %g5, (3 * 8), %g5 ! next entry + +/* + * 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: + brgez,pn %g4, kvmap_nonlinear + nop + +#ifdef CONFIG_DEBUG_PAGEALLOC + .globl kvmap_linear_patch +kvmap_linear_patch: +#endif + ba,pt %xcc, kvmap_load + xor %g2, %g4, %g5 + +#ifdef CONFIG_DEBUG_PAGEALLOC + sethi %hi(swapper_pg_dir), %g5 + or %g5, %lo(swapper_pg_dir), %g5 + sllx %g4, 64 - (PGDIR_SHIFT + PGDIR_BITS), %g6 + srlx %g6, 64 - PAGE_SHIFT, %g6 + andn %g6, 0x3, %g6 + lduw [%g5 + %g6], %g5 + brz,pn %g5, longpath + sllx %g4, 64 - (PMD_SHIFT + PMD_BITS), %g6 + srlx %g6, 64 - PAGE_SHIFT, %g6 + sllx %g5, 11, %g5 + andn %g6, 0x3, %g6 + lduwa [%g5 + %g6] ASI_PHYS_USE_EC, %g5 + brz,pn %g5, longpath + sllx %g4, 64 - PMD_SHIFT, %g6 + srlx %g6, 64 - PAGE_SHIFT, %g6 + sllx %g5, 11, %g5 + andn %g6, 0x7, %g6 + ldxa [%g5 + %g6] ASI_PHYS_USE_EC, %g5 + brz,pn %g5, longpath + nop + ba,a,pt %xcc, kvmap_load +#endif + +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, kvmap_do_obp + 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 |