/* SPDX-License-Identifier: GPL-2.0 */
/* tsb.S: Sparc64 TSB table handling.
 *
 * Copyright (C) 2006 David S. Miller <davem@davemloft.net>
 */


#include <asm/tsb.h>
#include <asm/hypervisor.h>
#include <asm/page.h>
#include <asm/cpudata.h>
#include <asm/mmu.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
        ldxa            [%g4] ASI_DMMU, %g4
        srlx            %g4, PAGE_SHIFT, %g4
        ba,pt           %xcc, tsb_miss_page_table_walk
         sllx           %g4, PAGE_SHIFT, %g4

tsb_miss_itlb:
        mov             TLB_TAG_ACCESS, %g4
        ldxa            [%g4] ASI_IMMU, %g4
        srlx            %g4, PAGE_SHIFT, %g4
        ba,pt           %xcc, tsb_miss_page_table_walk
         sllx           %g4, PAGE_SHIFT, %g4

        /* At this point we have:
         * %g1 --       PAGE_SIZE TSB entry address
         * %g3 --       FAULT_CODE_{D,I}TLB
         * %g4 --       missing virtual address
         * %g6 --       TAG TARGET (vaddr >> 22)
         */
tsb_miss_page_table_walk:
        TRAP_LOAD_TRAP_BLOCK(%g7, %g5)

        /* Before committing to a full page table walk,
         * check the huge page TSB.
         */
#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)

661:    ldx             [%g7 + TRAP_PER_CPU_TSB_HUGE], %g5
        nop
        .section        .sun4v_2insn_patch, "ax"
        .word           661b
        mov             SCRATCHPAD_UTSBREG2, %g5
        ldxa            [%g5] ASI_SCRATCHPAD, %g5
        .previous

        cmp             %g5, -1
        be,pt           %xcc, 80f
         nop

        /* We need an aligned pair of registers containing 2 values
         * which can be easily rematerialized.  %g6 and %g7 foot the
         * bill just nicely.  We'll save %g6 away into %g2 for the
         * huge page TSB TAG comparison.
         *
         * Perform a huge page TSB lookup.
         */
        mov             %g6, %g2
        and             %g5, 0x7, %g6
        mov             512, %g7
        andn            %g5, 0x7, %g5
        sllx            %g7, %g6, %g7
        srlx            %g4, REAL_HPAGE_SHIFT, %g6
        sub             %g7, 1, %g7
        and             %g6, %g7, %g6
        sllx            %g6, 4, %g6
        add             %g5, %g6, %g5

        TSB_LOAD_QUAD(%g5, %g6)
        cmp             %g6, %g2
        be,a,pt         %xcc, tsb_tlb_reload
         mov            %g7, %g5

        /* No match, remember the huge page TSB entry address,
         * and restore %g6 and %g7.
         */
        TRAP_LOAD_TRAP_BLOCK(%g7, %g6)
        srlx            %g4, 22, %g6
80:     stx             %g5, [%g7 + TRAP_PER_CPU_TSB_HUGE_TEMP]

#endif

        ldx             [%g7 + TRAP_PER_CPU_PGD_PADDR], %g7

        /* At this point we have:
         * %g1 --       TSB entry address
         * %g3 --       FAULT_CODE_{D,I}TLB
         * %g4 --       missing virtual address
         * %g6 --       TAG TARGET (vaddr >> 22)
         * %g7 --       page table physical address
         *
         * We know that both the base PAGE_SIZE TSB and the HPAGE_SIZE
         * TSB both lack a matching entry.
         */
tsb_miss_page_table_walk_sun4v_fastpath:
        USER_PGTABLE_WALK_TL1(%g4, %g7, %g5, %g2, tsb_do_fault)

        /* Valid PTE is now in %g5.  */

#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
        sethi           %uhi(_PAGE_PMD_HUGE | _PAGE_PUD_HUGE), %g7
        sllx            %g7, 32, %g7

        andcc           %g5, %g7, %g0
        be,pt           %xcc, 60f
         nop

        /* It is a huge page, use huge page TSB entry address we
         * calculated above.  If the huge page TSB has not been
         * allocated, setup a trap stack and call hugetlb_setup()
         * to do so, then return from the trap to replay the TLB
         * miss.
         *
         * This is necessary to handle the case of transparent huge
         * pages where we don't really have a non-atomic context
         * in which to allocate the hugepage TSB hash table.  When
         * the 'mm' faults in the hugepage for the first time, we
         * thus handle it here.  This also makes sure that we can
         * allocate the TSB hash table on the correct NUMA node.
         */
        TRAP_LOAD_TRAP_BLOCK(%g7, %g2)
        ldx             [%g7 + TRAP_PER_CPU_TSB_HUGE_TEMP], %g1
        cmp             %g1, -1
        bne,pt          %xcc, 60f
         nop

661:    rdpr            %pstate, %g5
        wrpr            %g5, PSTATE_AG | PSTATE_MG, %pstate
        .section        .sun4v_2insn_patch, "ax"
        .word           661b
        SET_GL(1)
        nop
        .previous

        rdpr    %tl, %g7
        cmp     %g7, 1
        bne,pn  %xcc, winfix_trampoline
         mov    %g3, %g4
        ba,pt   %xcc, etrap
         rd     %pc, %g7
        call    hugetlb_setup
         add    %sp, PTREGS_OFF, %o0
        ba,pt   %xcc, rtrap
         nop

60:
#endif

        /* At this point we have:
         * %g1 --       TSB entry address
         * %g3 --       FAULT_CODE_{D,I}TLB
         * %g5 --       valid PTE
         * %g6 --       TAG TARGET (vaddr >> 22)
         */
tsb_reload:
        TSB_LOCK_TAG(%g1, %g2, %g7)
        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:
        /* Executable bit must be set.  */
661:    sethi           %hi(_PAGE_EXEC_4U), %g4
        andcc           %g5, %g4, %g0
        .section        .sun4v_2insn_patch, "ax"
        .word           661b
        andcc           %g5, _PAGE_EXEC_4V, %g0
        nop
        .previous

        be,pn           %xcc, tsb_do_fault
         nop

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
        SET_GL(1)
        ldxa            [%g0] ASI_SCRATCHPAD, %g4
        .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
        ldx     [%g4 + HV_FAULT_D_ADDR_OFFSET], %g5
        nop
        .previous

        /* Clear context ID bits.  */
        srlx            %g5, PAGE_SHIFT, %g5
        sllx            %g5, PAGE_SHIFT, %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:
        /* 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                     ! 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
        .size   __tsb_insert, .-__tsb_insert

        /* 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
        .type   tsb_flush,#function
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
         nop
        cmp     %g1, %o1
        mov     1, %o3
        bne,pt  %xcc, 2f
         sllx   %o3, TSB_TAG_INVALID_BIT, %o3
        TSB_CAS_TAG(%o0, %g1, %o3)
        cmp     %g1, %o3
        bne,pn  %xcc, 1b
         nop
2:      retl
         nop
        .size   tsb_flush, .-tsb_flush

        /* Reload MMU related context switch state at
         * schedule() time.
         *
         * %o0: page table physical address
         * %o1: TSB base config pointer
         * %o2: TSB huge config pointer, or NULL if none
         * %o3: Hypervisor TSB descriptor physical address
         * %o4: Secondary context to load, if non-zero
         *
         * 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
        .type   __tsb_context_switch,#function
__tsb_context_switch:
        rdpr    %pstate, %g1
        wrpr    %g1, PSTATE_IE, %pstate

        brz,pn  %o4, 1f
         mov    SECONDARY_CONTEXT, %o5

661:    stxa    %o4, [%o5] ASI_DMMU
        .section .sun4v_1insn_patch, "ax"
        .word   661b
        stxa    %o4, [%o5] ASI_MMU
        .previous
        flush   %g6

1:
        TRAP_LOAD_TRAP_BLOCK(%g2, %g3)

        stx     %o0, [%g2 + TRAP_PER_CPU_PGD_PADDR]

        ldx     [%o1 + TSB_CONFIG_REG_VAL], %o0
        brz,pt  %o2, 1f
         mov    -1, %g3

        ldx     [%o2 + TSB_CONFIG_REG_VAL], %g3

1:      stx     %g3, [%g2 + TRAP_PER_CPU_TSB_HUGE]

        sethi   %hi(tlb_type), %g2
        lduw    [%g2 + %lo(tlb_type)], %g2
        cmp     %g2, 3
        bne,pt  %icc, 50f
         nop

        /* Hypervisor TSB switch. */
        mov     SCRATCHPAD_UTSBREG1, %o5
        stxa    %o0, [%o5] ASI_SCRATCHPAD
        mov     SCRATCHPAD_UTSBREG2, %o5
        stxa    %g3, [%o5] ASI_SCRATCHPAD

        mov     2, %o0
        cmp     %g3, -1
        move    %xcc, 1, %o0

        mov     HV_FAST_MMU_TSB_CTXNON0, %o5
        mov     %o3, %o1
        ta      HV_FAST_TRAP

        /* Finish up.  */
        ba,pt   %xcc, 9f
         nop

        /* SUN4U TSB switch.  */
50:     mov     TSB_REG, %o5
        stxa    %o0, [%o5] ASI_DMMU
        membar  #Sync
        stxa    %o0, [%o5] ASI_IMMU
        membar  #Sync

2:      ldx     [%o1 + TSB_CONFIG_MAP_VADDR], %o4
        brz     %o4, 9f
         ldx    [%o1 + TSB_CONFIG_MAP_PTE], %o5

        sethi   %hi(sparc64_highest_unlocked_tlb_ent), %g2
        mov     TLB_TAG_ACCESS, %g3
        lduw    [%g2 + %lo(sparc64_highest_unlocked_tlb_ent)], %g2
        stxa    %o4, [%g3] ASI_DMMU
        membar  #Sync
        sllx    %g2, 3, %g2
        stxa    %o5, [%g2] ASI_DTLB_DATA_ACCESS
        membar  #Sync

        brz,pt  %o2, 9f
         nop

        ldx     [%o2 + TSB_CONFIG_MAP_VADDR], %o4
        ldx     [%o2 + TSB_CONFIG_MAP_PTE], %o5
        mov     TLB_TAG_ACCESS, %g3
        stxa    %o4, [%g3] ASI_DMMU
        membar  #Sync
        sub     %g2, (1 << 3), %g2
        stxa    %o5, [%g2] ASI_DTLB_DATA_ACCESS
        membar  #Sync

9:
        wrpr    %g1, %pstate

        retl
         nop
        .size   __tsb_context_switch, .-__tsb_context_switch

#define TSB_PASS_BITS   ((1 << TSB_TAG_LOCK_BIT) | \
                         (1 << TSB_TAG_INVALID_BIT))

        .align  32
        .globl  copy_tsb
        .type   copy_tsb,#function
copy_tsb:               /* %o0=old_tsb_base, %o1=old_tsb_size
                         * %o2=new_tsb_base, %o3=new_tsb_size
                         * %o4=page_size_shift
                         */
        sethi           %uhi(TSB_PASS_BITS), %g7
        srlx            %o3, 4, %o3
        add             %o0, %o1, %o1   /* end of old tsb */
        sllx            %g7, 32, %g7
        sub             %o3, 1, %o3     /* %o3 == new tsb hash mask */

        mov             %o4, %g1        /* page_size_shift */

661:    prefetcha       [%o0] ASI_N, #one_read
        .section        .tsb_phys_patch, "ax"
        .word           661b
        prefetcha       [%o0] ASI_PHYS_USE_EC, #one_read
        .previous

90:     andcc           %o0, (64 - 1), %g0
        bne             1f
         add            %o0, 64, %o5

661:    prefetcha       [%o5] ASI_N, #one_read
        .section        .tsb_phys_patch, "ax"
        .word           661b
        prefetcha       [%o5] ASI_PHYS_USE_EC, #one_read
        .previous

1:      TSB_LOAD_QUAD(%o0, %g2)         /* %g2/%g3 == TSB entry */
        andcc           %g2, %g7, %g0   /* LOCK or INVALID set? */
        bne,pn          %xcc, 80f       /* Skip it */
         sllx           %g2, 22, %o4    /* TAG --> VADDR */

        /* This can definitely be computed faster... */
        srlx            %o0, 4, %o5     /* Build index */
        and             %o5, 511, %o5   /* Mask index */
        sllx            %o5, %g1, %o5   /* Put into vaddr position */
        or              %o4, %o5, %o4   /* Full VADDR. */
        srlx            %o4, %g1, %o4   /* Shift down to create index */
        and             %o4, %o3, %o4   /* Mask with new_tsb_nents-1 */
        sllx            %o4, 4, %o4     /* Shift back up into tsb ent offset */
        TSB_STORE(%o2 + %o4, %g2)       /* Store TAG */
        add             %o4, 0x8, %o4   /* Advance to TTE */
        TSB_STORE(%o2 + %o4, %g3)       /* Store TTE */

80:     add             %o0, 16, %o0
        cmp             %o0, %o1
        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