diff options
Diffstat (limited to 'arch/sparc64/kernel/tsb.S')
| -rw-r--r-- | arch/sparc64/kernel/tsb.S | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/tsb.S b/arch/sparc64/kernel/tsb.S new file mode 100644 index 00000000000..44b9e6fed09 --- /dev/null +++ b/arch/sparc64/kernel/tsb.S @@ -0,0 +1,169 @@ +/* tsb.S: Sparc64 TSB table handling. + * + * Copyright (C) 2006 David S. Miller <davem@davemloft.net> + */ + +#include <asm/tsb.h> + + .text + .align 32 + + /* Invoked from TLB miss handler, we are in the + * MMU global registers and they are setup like + * this: + * + * %g1: TSB entry pointer + * %g2: available temporary + * %g3: FAULT_CODE_{D,I}TLB + * %g4: available temporary + * %g5: available temporary + * %g6: TAG TARGET + * %g7: physical address base of the linux page + * tables for the current address space + */ + .globl tsb_miss_dtlb +tsb_miss_dtlb: + mov TLB_TAG_ACCESS, %g4 + ldxa [%g4] ASI_DMMU, %g4 + ba,pt %xcc, tsb_miss_page_table_walk + nop + + .globl tsb_miss_itlb +tsb_miss_itlb: + mov TLB_TAG_ACCESS, %g4 + ldxa [%g4] ASI_IMMU, %g4 + ba,pt %xcc, tsb_miss_page_table_walk + nop + +tsb_miss_page_table_walk: + USER_PGTABLE_WALK_TL1(%g4, %g7, %g5, %g2, tsb_do_fault) + +tsb_reload: + TSB_LOCK_TAG(%g1, %g2, %g4) + + /* Load and check PTE. */ + ldxa [%g5] ASI_PHYS_USE_EC, %g5 + brgez,a,pn %g5, tsb_do_fault + stx %g0, [%g1] + + TSB_WRITE(%g1, %g5, %g6) + + /* Finally, load TLB and return from trap. */ +tsb_tlb_reload: + cmp %g3, FAULT_CODE_DTLB + bne,pn %xcc, tsb_itlb_load + nop + +tsb_dtlb_load: + stxa %g5, [%g0] ASI_DTLB_DATA_IN + retry + +tsb_itlb_load: + stxa %g5, [%g0] ASI_ITLB_DATA_IN + retry + + /* No valid entry in the page tables, do full fault + * processing. + */ + + .globl tsb_do_fault +tsb_do_fault: + cmp %g3, FAULT_CODE_DTLB + rdpr %pstate, %g5 + bne,pn %xcc, tsb_do_itlb_fault + wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate + +tsb_do_dtlb_fault: + rdpr %tl, %g4 + cmp %g4, 1 + mov TLB_TAG_ACCESS, %g4 + ldxa [%g4] ASI_DMMU, %g5 + be,pt %xcc, sparc64_realfault_common + mov FAULT_CODE_DTLB, %g4 + ba,pt %xcc, winfix_trampoline + nop + +tsb_do_itlb_fault: + rdpr %tpc, %g5 + ba,pt %xcc, sparc64_realfault_common + mov FAULT_CODE_ITLB, %g4 + + .globl sparc64_realfault_common +sparc64_realfault_common: + stb %g4, [%g6 + TI_FAULT_CODE] ! Save fault code + stx %g5, [%g6 + TI_FAULT_ADDR] ! Save fault address + ba,pt %xcc, etrap ! Save trap state +1: rd %pc, %g7 ! ... + call do_sparc64_fault ! Call fault handler + add %sp, PTREGS_OFF, %o0 ! Compute pt_regs arg + ba,pt %xcc, rtrap_clr_l6 ! Restore cpu state + nop ! Delay slot (fill me) + + .globl winfix_trampoline +winfix_trampoline: + rdpr %tpc, %g3 ! Prepare winfixup TNPC + or %g3, 0x7c, %g3 ! Compute branch offset + wrpr %g3, %tnpc ! Write it into TNPC + done ! Trap return + + /* Reload MMU related context switch state at + * schedule() time. + * + * %o0: page table physical address + * %o1: TSB address + */ + .globl tsb_context_switch +tsb_context_switch: + wrpr %g0, PSTATE_MG | PSTATE_RMO | PSTATE_PEF | PSTATE_PRIV, %pstate + + /* Set page table base alternate global. */ + mov %o0, %g7 + + /* XXX can this happen? */ + brz,pn %o1, 9f + nop + + /* Lock TSB into D-TLB. */ + sethi %hi(PAGE_SIZE), %o3 + and %o3, %o1, %o3 + sethi %hi(TSBMAP_BASE), %o2 + add %o2, %o3, %o2 + + /* XXX handle PAGE_SIZE != 8K correctly... */ + mov TSB_REG, %g1 + stxa %o2, [%g1] ASI_DMMU + membar #Sync + + stxa %o2, [%g1] ASI_IMMU + membar #Sync + +#define KERN_HIGHBITS ((_PAGE_VALID|_PAGE_SZBITS)^0xfffff80000000000) +#define KERN_LOWBITS (_PAGE_CP | _PAGE_CV | _PAGE_P | _PAGE_W | _PAGE_L) + sethi %uhi(KERN_HIGHBITS), %g2 + or %g2, %ulo(KERN_HIGHBITS), %g2 + sllx %g2, 32, %g2 + or %g2, KERN_LOWBITS, %g2 +#undef KERN_HIGHBITS +#undef KERN_LOWBITS + + xor %o1, %g2, %o1 + + /* We use entry 61 for this locked entry. This is the spitfire + * TLB entry number, and luckily cheetah masks the value with + * 15 ending us up with entry 13 which is what we want in that + * case too. + * + * XXX Interactions with prom_world()... + */ + mov TLB_TAG_ACCESS, %g1 + stxa %o2, [%g1] ASI_DMMU + membar #Sync + mov (61 << 3), %g1 + stxa %o1, [%g1] ASI_DTLB_DATA_ACCESS + membar #Sync + +9: + wrpr %g0, PSTATE_RMO | PSTATE_PEF | PSTATE_PRIV | PSTATE_IE, %pstate + + retl + mov %o2, %o0 |