mirror of
https://github.com/torvalds/linux.git
synced 2024-12-27 13:22:23 +00:00
36a68e77c5
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 <davem@davemloft.net>
298 lines
6.2 KiB
ArmAsm
298 lines
6.2 KiB
ArmAsm
/* tsb.S: Sparc64 TSB table handling.
|
|
*
|
|
* Copyright (C) 2006 David S. Miller <davem@davemloft.net>
|
|
*/
|
|
|
|
#include <asm/tsb.h>
|
|
#include <asm/hypervisor.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: available temporary, will be loaded by us with
|
|
* the physical address base of the linux page
|
|
* tables for the current address space
|
|
*/
|
|
tsb_miss_dtlb:
|
|
mov TLB_TAG_ACCESS, %g4
|
|
ba,pt %xcc, tsb_miss_page_table_walk
|
|
ldxa [%g4] ASI_DMMU, %g4
|
|
|
|
tsb_miss_itlb:
|
|
mov TLB_TAG_ACCESS, %g4
|
|
ba,pt %xcc, tsb_miss_page_table_walk
|
|
ldxa [%g4] ASI_IMMU, %g4
|
|
|
|
/* 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:
|
|
TSB_LOCK_TAG(%g1, %g2, %g7)
|
|
|
|
/* Load and check PTE. */
|
|
ldxa [%g5] ASI_PHYS_USE_EC, %g5
|
|
brgez,a,pn %g5, tsb_do_fault
|
|
TSB_STORE(%g1, %g0)
|
|
|
|
/* If it is larger than the base page size, don't
|
|
* bother putting it into the TSB.
|
|
*/
|
|
srlx %g5, 32, %g2
|
|
sethi %hi(_PAGE_ALL_SZ_BITS >> 32), %g7
|
|
and %g2, %g7, %g2
|
|
sethi %hi(_PAGE_SZBITS >> 32), %g7
|
|
cmp %g2, %g7
|
|
bne,a,pn %xcc, tsb_tlb_reload
|
|
TSB_STORE(%g1, %g0)
|
|
|
|
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:
|
|
|
|
661: stxa %g5, [%g0] ASI_DTLB_DATA_IN
|
|
retry
|
|
.section .sun4v_2insn_patch, "ax"
|
|
.word 661b
|
|
nop
|
|
nop
|
|
.previous
|
|
|
|
/* For sun4v the ASI_DTLB_DATA_IN store and the retry
|
|
* instruction get nop'd out and we get here to branch
|
|
* to the sun4v tlb load code. The registers are setup
|
|
* as follows:
|
|
*
|
|
* %g4: vaddr
|
|
* %g5: PTE
|
|
* %g6: TAG
|
|
*
|
|
* The sun4v TLB load wants the PTE in %g3 so we fix that
|
|
* up here.
|
|
*/
|
|
ba,pt %xcc, sun4v_dtlb_load
|
|
mov %g5, %g3
|
|
|
|
tsb_itlb_load:
|
|
|
|
661: stxa %g5, [%g0] ASI_ITLB_DATA_IN
|
|
retry
|
|
.section .sun4v_2insn_patch, "ax"
|
|
.word 661b
|
|
nop
|
|
nop
|
|
.previous
|
|
|
|
/* For sun4v the ASI_ITLB_DATA_IN store and the retry
|
|
* instruction get nop'd out and we get here to branch
|
|
* to the sun4v tlb load code. The registers are setup
|
|
* as follows:
|
|
*
|
|
* %g4: vaddr
|
|
* %g5: PTE
|
|
* %g6: TAG
|
|
*
|
|
* The sun4v TLB load wants the PTE in %g3 so we fix that
|
|
* up here.
|
|
*/
|
|
ba,pt %xcc, sun4v_itlb_load
|
|
mov %g5, %g3
|
|
|
|
/* No valid entry in the page tables, do full fault
|
|
* processing.
|
|
*/
|
|
|
|
.globl tsb_do_fault
|
|
tsb_do_fault:
|
|
cmp %g3, FAULT_CODE_DTLB
|
|
|
|
661: rdpr %pstate, %g5
|
|
wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate
|
|
.section .sun4v_2insn_patch, "ax"
|
|
.word 661b
|
|
nop
|
|
nop
|
|
.previous
|
|
|
|
bne,pn %xcc, tsb_do_itlb_fault
|
|
nop
|
|
|
|
tsb_do_dtlb_fault:
|
|
rdpr %tl, %g3
|
|
cmp %g3, 1
|
|
|
|
661: mov TLB_TAG_ACCESS, %g4
|
|
ldxa [%g4] ASI_DMMU, %g5
|
|
.section .sun4v_2insn_patch, "ax"
|
|
.word 661b
|
|
mov %g4, %g5
|
|
nop
|
|
.previous
|
|
|
|
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:
|
|
/* fault code in %g4, fault address in %g5, etrap will
|
|
* preserve these two values in %l4 and %l5 respectively
|
|
*/
|
|
ba,pt %xcc, etrap ! Save trap state
|
|
1: rd %pc, %g7 ! ...
|
|
stb %l4, [%g6 + TI_FAULT_CODE] ! Save fault code
|
|
stx %l5, [%g6 + TI_FAULT_ADDR] ! Save fault address
|
|
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)
|
|
|
|
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
|
|
|
|
/* Insert an entry into the TSB.
|
|
*
|
|
* %o0: TSB entry pointer (virt or phys address)
|
|
* %o1: tag
|
|
* %o2: pte
|
|
*/
|
|
.align 32
|
|
.globl __tsb_insert
|
|
__tsb_insert:
|
|
rdpr %pstate, %o5
|
|
wrpr %o5, PSTATE_IE, %pstate
|
|
TSB_LOCK_TAG(%o0, %g2, %g3)
|
|
TSB_WRITE(%o0, %o2, %o1)
|
|
wrpr %o5, %pstate
|
|
retl
|
|
nop
|
|
|
|
/* Flush the given TSB entry if it has the matching
|
|
* tag.
|
|
*
|
|
* %o0: TSB entry pointer (virt or phys address)
|
|
* %o1: tag
|
|
*/
|
|
.align 32
|
|
.globl tsb_flush
|
|
tsb_flush:
|
|
sethi %hi(TSB_TAG_LOCK_HIGH), %g2
|
|
1: TSB_LOAD_TAG(%o0, %g1)
|
|
srlx %g1, 32, %o3
|
|
andcc %o3, %g2, %g0
|
|
bne,pn %icc, 1b
|
|
membar #LoadLoad
|
|
cmp %g1, %o1
|
|
bne,pt %xcc, 2f
|
|
clr %o3
|
|
TSB_CAS_TAG(%o0, %g1, %o3)
|
|
cmp %g1, %o3
|
|
bne,pn %xcc, 1b
|
|
nop
|
|
2: retl
|
|
TSB_MEMBAR
|
|
|
|
/* Reload MMU related context switch state at
|
|
* schedule() time.
|
|
*
|
|
* %o0: page table physical address
|
|
* %o1: TSB register value
|
|
* %o2: TSB virtual address
|
|
* %o3: TSB mapping locked PTE
|
|
* %o4: Hypervisor TSB descriptor physical address
|
|
*
|
|
* We have to run this whole thing with interrupts
|
|
* disabled so that the current cpu doesn't change
|
|
* due to preemption.
|
|
*/
|
|
.align 32
|
|
.globl __tsb_context_switch
|
|
__tsb_context_switch:
|
|
rdpr %pstate, %o5
|
|
wrpr %o5, PSTATE_IE, %pstate
|
|
|
|
ldub [%g6 + TI_CPU], %g1
|
|
sethi %hi(trap_block), %g2
|
|
sllx %g1, TRAP_BLOCK_SZ_SHIFT, %g1
|
|
or %g2, %lo(trap_block), %g2
|
|
add %g2, %g1, %g2
|
|
stx %o0, [%g2 + TRAP_PER_CPU_PGD_PADDR]
|
|
|
|
sethi %hi(tlb_type), %g1
|
|
lduw [%g1 + %lo(tlb_type)], %g1
|
|
cmp %g1, 3
|
|
bne,pt %icc, 1f
|
|
nop
|
|
|
|
/* Hypervisor TSB switch. */
|
|
mov SCRATCHPAD_UTSBREG1, %g1
|
|
stxa %o1, [%g1] ASI_SCRATCHPAD
|
|
mov -1, %g2
|
|
mov SCRATCHPAD_UTSBREG2, %g1
|
|
stxa %g2, [%g1] ASI_SCRATCHPAD
|
|
|
|
mov HV_FAST_MMU_TSB_CTXNON0, %o5
|
|
mov 1, %o0
|
|
mov %o4, %o1
|
|
ta HV_FAST_TRAP
|
|
|
|
ba,pt %xcc, 9f
|
|
nop
|
|
|
|
/* SUN4U TSB switch. */
|
|
1: mov TSB_REG, %g1
|
|
stxa %o1, [%g1] ASI_DMMU
|
|
membar #Sync
|
|
stxa %o1, [%g1] ASI_IMMU
|
|
membar #Sync
|
|
|
|
2: brz %o2, 9f
|
|
nop
|
|
|
|
sethi %hi(sparc64_highest_unlocked_tlb_ent), %g2
|
|
mov TLB_TAG_ACCESS, %g1
|
|
lduw [%g2 + %lo(sparc64_highest_unlocked_tlb_ent)], %g2
|
|
stxa %o2, [%g1] ASI_DMMU
|
|
membar #Sync
|
|
sllx %g2, 3, %g2
|
|
stxa %o3, [%g2] ASI_DTLB_DATA_ACCESS
|
|
membar #Sync
|
|
9:
|
|
wrpr %o5, %pstate
|
|
|
|
retl
|
|
nop
|