![David S. Miller](/assets/img/avatar_default.png)
Thanks to testcase and report from Brad Spengler: -------------------- #include <stdio.h> typedef int (* _wee)(void); int main(void) { char buf[8] = { '\x81', '\xc7', '\xe0', '\x08', '\x81', '\xe8', '\x00', '\x00' }; _wee wee; printf("%p\n", &buf); wee = (_wee)&buf; wee(); return 0; } -------------------- TSB I-tlb load code tries to use andcc to check the _PAGE_EXEC_4U bit, but that's bit 12 so it gets sign extended all the way up to bit 63 and the test nearly always passes as a result. Use sethi to fix the bug. Signed-off-by: David S. Miller <davem@davemloft.net>
555 lines
12 KiB
ArmAsm
555 lines
12 KiB
ArmAsm
/* tsb.S: Sparc64 TSB table handling.
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*
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* Copyright (C) 2006 David S. Miller <davem@davemloft.net>
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*/
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#include <asm/tsb.h>
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#include <asm/hypervisor.h>
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#include <asm/page.h>
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#include <asm/cpudata.h>
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#include <asm/mmu.h>
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.text
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.align 32
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/* Invoked from TLB miss handler, we are in the
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* MMU global registers and they are setup like
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* this:
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*
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* %g1: TSB entry pointer
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* %g2: available temporary
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* %g3: FAULT_CODE_{D,I}TLB
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* %g4: available temporary
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* %g5: available temporary
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* %g6: TAG TARGET
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* %g7: available temporary, will be loaded by us with
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* the physical address base of the linux page
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* tables for the current address space
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*/
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tsb_miss_dtlb:
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mov TLB_TAG_ACCESS, %g4
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ba,pt %xcc, tsb_miss_page_table_walk
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ldxa [%g4] ASI_DMMU, %g4
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tsb_miss_itlb:
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mov TLB_TAG_ACCESS, %g4
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ba,pt %xcc, tsb_miss_page_table_walk
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ldxa [%g4] ASI_IMMU, %g4
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/* At this point we have:
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* %g1 -- PAGE_SIZE TSB entry address
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* %g3 -- FAULT_CODE_{D,I}TLB
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* %g4 -- missing virtual address
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* %g6 -- TAG TARGET (vaddr >> 22)
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*/
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tsb_miss_page_table_walk:
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TRAP_LOAD_TRAP_BLOCK(%g7, %g5)
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/* Before committing to a full page table walk,
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* check the huge page TSB.
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*/
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#ifdef CONFIG_HUGETLB_PAGE
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661: ldx [%g7 + TRAP_PER_CPU_TSB_HUGE], %g5
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nop
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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mov SCRATCHPAD_UTSBREG2, %g5
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ldxa [%g5] ASI_SCRATCHPAD, %g5
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.previous
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cmp %g5, -1
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be,pt %xcc, 80f
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nop
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/* We need an aligned pair of registers containing 2 values
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* which can be easily rematerialized. %g6 and %g7 foot the
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* bill just nicely. We'll save %g6 away into %g2 for the
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* huge page TSB TAG comparison.
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*
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* Perform a huge page TSB lookup.
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*/
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mov %g6, %g2
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and %g5, 0x7, %g6
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mov 512, %g7
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andn %g5, 0x7, %g5
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sllx %g7, %g6, %g7
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srlx %g4, HPAGE_SHIFT, %g6
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sub %g7, 1, %g7
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and %g6, %g7, %g6
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sllx %g6, 4, %g6
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add %g5, %g6, %g5
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TSB_LOAD_QUAD(%g5, %g6)
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cmp %g6, %g2
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be,a,pt %xcc, tsb_tlb_reload
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mov %g7, %g5
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/* No match, remember the huge page TSB entry address,
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* and restore %g6 and %g7.
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*/
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TRAP_LOAD_TRAP_BLOCK(%g7, %g6)
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srlx %g4, 22, %g6
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80: stx %g5, [%g7 + TRAP_PER_CPU_TSB_HUGE_TEMP]
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#endif
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ldx [%g7 + TRAP_PER_CPU_PGD_PADDR], %g7
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/* At this point we have:
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* %g1 -- TSB entry address
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* %g3 -- FAULT_CODE_{D,I}TLB
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* %g4 -- missing virtual address
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* %g6 -- TAG TARGET (vaddr >> 22)
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* %g7 -- page table physical address
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*
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* We know that both the base PAGE_SIZE TSB and the HPAGE_SIZE
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* TSB both lack a matching entry.
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*/
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tsb_miss_page_table_walk_sun4v_fastpath:
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USER_PGTABLE_WALK_TL1(%g4, %g7, %g5, %g2, tsb_do_fault)
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/* Load and check PTE. */
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ldxa [%g5] ASI_PHYS_USE_EC, %g5
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brgez,pn %g5, tsb_do_fault
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nop
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#ifdef CONFIG_HUGETLB_PAGE
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661: sethi %uhi(_PAGE_SZALL_4U), %g7
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sllx %g7, 32, %g7
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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mov _PAGE_SZALL_4V, %g7
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nop
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.previous
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and %g5, %g7, %g2
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661: sethi %uhi(_PAGE_SZHUGE_4U), %g7
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sllx %g7, 32, %g7
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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mov _PAGE_SZHUGE_4V, %g7
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nop
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.previous
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cmp %g2, %g7
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bne,pt %xcc, 60f
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nop
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/* It is a huge page, use huge page TSB entry address we
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* calculated above.
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*/
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TRAP_LOAD_TRAP_BLOCK(%g7, %g2)
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ldx [%g7 + TRAP_PER_CPU_TSB_HUGE_TEMP], %g2
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cmp %g2, -1
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movne %xcc, %g2, %g1
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60:
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#endif
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/* At this point we have:
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* %g1 -- TSB entry address
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* %g3 -- FAULT_CODE_{D,I}TLB
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* %g5 -- valid PTE
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* %g6 -- TAG TARGET (vaddr >> 22)
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*/
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tsb_reload:
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TSB_LOCK_TAG(%g1, %g2, %g7)
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TSB_WRITE(%g1, %g5, %g6)
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/* Finally, load TLB and return from trap. */
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tsb_tlb_reload:
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cmp %g3, FAULT_CODE_DTLB
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bne,pn %xcc, tsb_itlb_load
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nop
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tsb_dtlb_load:
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661: stxa %g5, [%g0] ASI_DTLB_DATA_IN
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retry
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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nop
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nop
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.previous
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/* For sun4v the ASI_DTLB_DATA_IN store and the retry
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* instruction get nop'd out and we get here to branch
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* to the sun4v tlb load code. The registers are setup
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* as follows:
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*
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* %g4: vaddr
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* %g5: PTE
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* %g6: TAG
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*
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* The sun4v TLB load wants the PTE in %g3 so we fix that
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* up here.
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*/
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ba,pt %xcc, sun4v_dtlb_load
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mov %g5, %g3
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tsb_itlb_load:
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/* Executable bit must be set. */
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661: sethi %hi(_PAGE_EXEC_4U), %g4
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andcc %g5, %g4, %g0
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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andcc %g5, _PAGE_EXEC_4V, %g0
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nop
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.previous
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be,pn %xcc, tsb_do_fault
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nop
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661: stxa %g5, [%g0] ASI_ITLB_DATA_IN
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retry
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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nop
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nop
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.previous
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/* For sun4v the ASI_ITLB_DATA_IN store and the retry
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* instruction get nop'd out and we get here to branch
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* to the sun4v tlb load code. The registers are setup
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* as follows:
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*
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* %g4: vaddr
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* %g5: PTE
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* %g6: TAG
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*
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* The sun4v TLB load wants the PTE in %g3 so we fix that
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* up here.
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*/
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ba,pt %xcc, sun4v_itlb_load
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mov %g5, %g3
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/* No valid entry in the page tables, do full fault
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* processing.
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*/
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.globl tsb_do_fault
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tsb_do_fault:
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cmp %g3, FAULT_CODE_DTLB
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661: rdpr %pstate, %g5
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wrpr %g5, PSTATE_AG | PSTATE_MG, %pstate
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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SET_GL(1)
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ldxa [%g0] ASI_SCRATCHPAD, %g4
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.previous
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bne,pn %xcc, tsb_do_itlb_fault
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nop
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tsb_do_dtlb_fault:
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rdpr %tl, %g3
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cmp %g3, 1
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661: mov TLB_TAG_ACCESS, %g4
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ldxa [%g4] ASI_DMMU, %g5
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.section .sun4v_2insn_patch, "ax"
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.word 661b
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ldx [%g4 + HV_FAULT_D_ADDR_OFFSET], %g5
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nop
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.previous
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be,pt %xcc, sparc64_realfault_common
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mov FAULT_CODE_DTLB, %g4
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ba,pt %xcc, winfix_trampoline
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nop
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tsb_do_itlb_fault:
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rdpr %tpc, %g5
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ba,pt %xcc, sparc64_realfault_common
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mov FAULT_CODE_ITLB, %g4
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.globl sparc64_realfault_common
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sparc64_realfault_common:
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/* fault code in %g4, fault address in %g5, etrap will
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* preserve these two values in %l4 and %l5 respectively
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*/
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ba,pt %xcc, etrap ! Save trap state
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1: rd %pc, %g7 ! ...
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stb %l4, [%g6 + TI_FAULT_CODE] ! Save fault code
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stx %l5, [%g6 + TI_FAULT_ADDR] ! Save fault address
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call do_sparc64_fault ! Call fault handler
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add %sp, PTREGS_OFF, %o0 ! Compute pt_regs arg
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ba,pt %xcc, rtrap ! Restore cpu state
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nop ! Delay slot (fill me)
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winfix_trampoline:
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rdpr %tpc, %g3 ! Prepare winfixup TNPC
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or %g3, 0x7c, %g3 ! Compute branch offset
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wrpr %g3, %tnpc ! Write it into TNPC
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done ! Trap return
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/* Insert an entry into the TSB.
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*
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* %o0: TSB entry pointer (virt or phys address)
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* %o1: tag
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* %o2: pte
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*/
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.align 32
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.globl __tsb_insert
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__tsb_insert:
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rdpr %pstate, %o5
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wrpr %o5, PSTATE_IE, %pstate
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TSB_LOCK_TAG(%o0, %g2, %g3)
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TSB_WRITE(%o0, %o2, %o1)
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wrpr %o5, %pstate
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retl
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nop
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.size __tsb_insert, .-__tsb_insert
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/* Flush the given TSB entry if it has the matching
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* tag.
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*
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* %o0: TSB entry pointer (virt or phys address)
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* %o1: tag
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*/
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.align 32
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.globl tsb_flush
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.type tsb_flush,#function
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tsb_flush:
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sethi %hi(TSB_TAG_LOCK_HIGH), %g2
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1: TSB_LOAD_TAG(%o0, %g1)
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srlx %g1, 32, %o3
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andcc %o3, %g2, %g0
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bne,pn %icc, 1b
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nop
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cmp %g1, %o1
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mov 1, %o3
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bne,pt %xcc, 2f
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sllx %o3, TSB_TAG_INVALID_BIT, %o3
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TSB_CAS_TAG(%o0, %g1, %o3)
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cmp %g1, %o3
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bne,pn %xcc, 1b
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nop
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2: retl
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nop
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.size tsb_flush, .-tsb_flush
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/* Reload MMU related context switch state at
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* schedule() time.
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*
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* %o0: page table physical address
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* %o1: TSB base config pointer
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* %o2: TSB huge config pointer, or NULL if none
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* %o3: Hypervisor TSB descriptor physical address
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*
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* We have to run this whole thing with interrupts
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* disabled so that the current cpu doesn't change
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* due to preemption.
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*/
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.align 32
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.globl __tsb_context_switch
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.type __tsb_context_switch,#function
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__tsb_context_switch:
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rdpr %pstate, %g1
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wrpr %g1, PSTATE_IE, %pstate
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TRAP_LOAD_TRAP_BLOCK(%g2, %g3)
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stx %o0, [%g2 + TRAP_PER_CPU_PGD_PADDR]
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ldx [%o1 + TSB_CONFIG_REG_VAL], %o0
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brz,pt %o2, 1f
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mov -1, %g3
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ldx [%o2 + TSB_CONFIG_REG_VAL], %g3
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1: stx %g3, [%g2 + TRAP_PER_CPU_TSB_HUGE]
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sethi %hi(tlb_type), %g2
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lduw [%g2 + %lo(tlb_type)], %g2
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cmp %g2, 3
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bne,pt %icc, 50f
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nop
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/* Hypervisor TSB switch. */
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mov SCRATCHPAD_UTSBREG1, %o5
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stxa %o0, [%o5] ASI_SCRATCHPAD
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mov SCRATCHPAD_UTSBREG2, %o5
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stxa %g3, [%o5] ASI_SCRATCHPAD
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mov 2, %o0
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cmp %g3, -1
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move %xcc, 1, %o0
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mov HV_FAST_MMU_TSB_CTXNON0, %o5
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mov %o3, %o1
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ta HV_FAST_TRAP
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/* Finish up. */
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ba,pt %xcc, 9f
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nop
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/* SUN4U TSB switch. */
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50: mov TSB_REG, %o5
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stxa %o0, [%o5] ASI_DMMU
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membar #Sync
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stxa %o0, [%o5] ASI_IMMU
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membar #Sync
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2: ldx [%o1 + TSB_CONFIG_MAP_VADDR], %o4
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brz %o4, 9f
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ldx [%o1 + TSB_CONFIG_MAP_PTE], %o5
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sethi %hi(sparc64_highest_unlocked_tlb_ent), %g2
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mov TLB_TAG_ACCESS, %g3
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lduw [%g2 + %lo(sparc64_highest_unlocked_tlb_ent)], %g2
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stxa %o4, [%g3] ASI_DMMU
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membar #Sync
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sllx %g2, 3, %g2
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stxa %o5, [%g2] ASI_DTLB_DATA_ACCESS
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membar #Sync
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brz,pt %o2, 9f
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nop
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ldx [%o2 + TSB_CONFIG_MAP_VADDR], %o4
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ldx [%o2 + TSB_CONFIG_MAP_PTE], %o5
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mov TLB_TAG_ACCESS, %g3
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stxa %o4, [%g3] ASI_DMMU
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membar #Sync
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sub %g2, (1 << 3), %g2
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stxa %o5, [%g2] ASI_DTLB_DATA_ACCESS
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membar #Sync
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9:
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wrpr %g1, %pstate
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retl
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nop
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.size __tsb_context_switch, .-__tsb_context_switch
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#define TSB_PASS_BITS ((1 << TSB_TAG_LOCK_BIT) | \
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(1 << TSB_TAG_INVALID_BIT))
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.align 32
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.globl copy_tsb
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.type copy_tsb,#function
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copy_tsb: /* %o0=old_tsb_base, %o1=old_tsb_size
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* %o2=new_tsb_base, %o3=new_tsb_size
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*/
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sethi %uhi(TSB_PASS_BITS), %g7
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srlx %o3, 4, %o3
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add %o0, %o1, %g1 /* end of old tsb */
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sllx %g7, 32, %g7
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sub %o3, 1, %o3 /* %o3 == new tsb hash mask */
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661: prefetcha [%o0] ASI_N, #one_read
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.section .tsb_phys_patch, "ax"
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.word 661b
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prefetcha [%o0] ASI_PHYS_USE_EC, #one_read
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.previous
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90: andcc %o0, (64 - 1), %g0
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bne 1f
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add %o0, 64, %o5
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661: prefetcha [%o5] ASI_N, #one_read
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.section .tsb_phys_patch, "ax"
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.word 661b
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prefetcha [%o5] ASI_PHYS_USE_EC, #one_read
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.previous
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1: TSB_LOAD_QUAD(%o0, %g2) /* %g2/%g3 == TSB entry */
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andcc %g2, %g7, %g0 /* LOCK or INVALID set? */
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bne,pn %xcc, 80f /* Skip it */
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sllx %g2, 22, %o4 /* TAG --> VADDR */
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/* This can definitely be computed faster... */
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srlx %o0, 4, %o5 /* Build index */
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and %o5, 511, %o5 /* Mask index */
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sllx %o5, PAGE_SHIFT, %o5 /* Put into vaddr position */
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or %o4, %o5, %o4 /* Full VADDR. */
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srlx %o4, PAGE_SHIFT, %o4 /* Shift down to create index */
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and %o4, %o3, %o4 /* Mask with new_tsb_nents-1 */
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sllx %o4, 4, %o4 /* Shift back up into tsb ent offset */
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TSB_STORE(%o2 + %o4, %g2) /* Store TAG */
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add %o4, 0x8, %o4 /* Advance to TTE */
|
|
TSB_STORE(%o2 + %o4, %g3) /* Store TTE */
|
|
|
|
80: add %o0, 16, %o0
|
|
cmp %o0, %g1
|
|
bne,pt %xcc, 90b
|
|
nop
|
|
|
|
retl
|
|
nop
|
|
.size copy_tsb, .-copy_tsb
|
|
|
|
/* Set the invalid bit in all TSB entries. */
|
|
.align 32
|
|
.globl tsb_init
|
|
.type tsb_init,#function
|
|
tsb_init: /* %o0 = TSB vaddr, %o1 = size in bytes */
|
|
prefetch [%o0 + 0x000], #n_writes
|
|
mov 1, %g1
|
|
prefetch [%o0 + 0x040], #n_writes
|
|
sllx %g1, TSB_TAG_INVALID_BIT, %g1
|
|
prefetch [%o0 + 0x080], #n_writes
|
|
1: prefetch [%o0 + 0x0c0], #n_writes
|
|
stx %g1, [%o0 + 0x00]
|
|
stx %g1, [%o0 + 0x10]
|
|
stx %g1, [%o0 + 0x20]
|
|
stx %g1, [%o0 + 0x30]
|
|
prefetch [%o0 + 0x100], #n_writes
|
|
stx %g1, [%o0 + 0x40]
|
|
stx %g1, [%o0 + 0x50]
|
|
stx %g1, [%o0 + 0x60]
|
|
stx %g1, [%o0 + 0x70]
|
|
prefetch [%o0 + 0x140], #n_writes
|
|
stx %g1, [%o0 + 0x80]
|
|
stx %g1, [%o0 + 0x90]
|
|
stx %g1, [%o0 + 0xa0]
|
|
stx %g1, [%o0 + 0xb0]
|
|
prefetch [%o0 + 0x180], #n_writes
|
|
stx %g1, [%o0 + 0xc0]
|
|
stx %g1, [%o0 + 0xd0]
|
|
stx %g1, [%o0 + 0xe0]
|
|
stx %g1, [%o0 + 0xf0]
|
|
subcc %o1, 0x100, %o1
|
|
bne,pt %xcc, 1b
|
|
add %o0, 0x100, %o0
|
|
retl
|
|
nop
|
|
nop
|
|
nop
|
|
.size tsb_init, .-tsb_init
|
|
|
|
.globl NGtsb_init
|
|
.type NGtsb_init,#function
|
|
NGtsb_init:
|
|
rd %asi, %g2
|
|
mov 1, %g1
|
|
wr %g0, ASI_BLK_INIT_QUAD_LDD_P, %asi
|
|
sllx %g1, TSB_TAG_INVALID_BIT, %g1
|
|
1: stxa %g1, [%o0 + 0x00] %asi
|
|
stxa %g1, [%o0 + 0x10] %asi
|
|
stxa %g1, [%o0 + 0x20] %asi
|
|
stxa %g1, [%o0 + 0x30] %asi
|
|
stxa %g1, [%o0 + 0x40] %asi
|
|
stxa %g1, [%o0 + 0x50] %asi
|
|
stxa %g1, [%o0 + 0x60] %asi
|
|
stxa %g1, [%o0 + 0x70] %asi
|
|
stxa %g1, [%o0 + 0x80] %asi
|
|
stxa %g1, [%o0 + 0x90] %asi
|
|
stxa %g1, [%o0 + 0xa0] %asi
|
|
stxa %g1, [%o0 + 0xb0] %asi
|
|
stxa %g1, [%o0 + 0xc0] %asi
|
|
stxa %g1, [%o0 + 0xd0] %asi
|
|
stxa %g1, [%o0 + 0xe0] %asi
|
|
stxa %g1, [%o0 + 0xf0] %asi
|
|
subcc %o1, 0x100, %o1
|
|
bne,pt %xcc, 1b
|
|
add %o0, 0x100, %o0
|
|
membar #Sync
|
|
retl
|
|
wr %g2, 0x0, %asi
|
|
.size NGtsb_init, .-NGtsb_init
|