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diff --git a/arch/cris/arch-v32/mm/mmu.S b/arch/cris/arch-v32/mm/mmu.S
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-; SPDX-License-Identifier: GPL-2.0
-; WARNING : The refill handler has been modified, see below !!!
-
-/*
- * Copyright (C) 2003 Axis Communications AB
- *
- * Authors: Mikael Starvik (starvik@axis.com)
- *
- * Code for the fault low-level handling routines.
- *
- */
-
-#include <asm/page.h>
-#include <asm/pgtable.h>
-
-; Save all register. Must save in same order as struct pt_regs.
-.macro SAVE_ALL
- subq 12, $sp
- move $erp, [$sp]
- subq 4, $sp
- move $srp, [$sp]
- subq 4, $sp
- move $ccs, [$sp]
- subq 4, $sp
- move $spc, [$sp]
- subq 4, $sp
- move $mof, [$sp]
- subq 4, $sp
- move $srs, [$sp]
- subq 4, $sp
- move.d $acr, [$sp]
- subq 14*4, $sp
- movem $r13, [$sp]
- subq 4, $sp
- move.d $r10, [$sp]
-.endm
-
-; Bus fault handler. Extracts relevant information and calls mm subsystem
-; to handle the fault.
-.macro MMU_BUS_FAULT_HANDLER handler, mmu, we, ex
- .globl \handler
- .type \handler,"function"
-\handler:
- SAVE_ALL
- move \mmu, $srs ; Select MMU support register bank
- move.d $sp, $r11 ; regs
- moveq 1, $r12 ; protection fault
- moveq \we, $r13 ; write exception?
- orq \ex << 1, $r13 ; execute?
- move $s3, $r10 ; rw_mm_cause
- and.d ~8191, $r10 ; Get faulting page start address
-
- jsr do_page_fault
- nop
- ba ret_from_intr
- nop
- .size \handler, . - \handler
-.endm
-
-; Refill handler. Three cases may occur:
-; 1. PMD and PTE exists in mm subsystem but not in TLB
-; 2. PMD exists but not PTE
-; 3. PMD doesn't exist
-; The code below handles case 1 and calls the mm subsystem for case 2 and 3.
-; Do not touch this code without very good reasons and extensive testing.
-; Note that the code is optimized to minimize stalls (makes the code harder
-; to read).
-;
-; WARNING !!!
-; Modified by Mikael Asker 060725: added a workaround for strange TLB
-; behavior. If the same PTE is present in more than one set, the TLB
-; doesn't recognize it and we get stuck in a loop of refill exceptions.
-; The workaround detects such loops and exits them by flushing
-; the TLB contents. The problem and workaround were verified
-; in VCS by Mikael Starvik.
-;
-; Each page is 8 KB. Each PMD holds 8192/4 PTEs (each PTE is 4 bytes) so each
-; PMD holds 16 MB of virtual memory.
-; Bits 0-12 : Offset within a page
-; Bits 13-23 : PTE offset within a PMD
-; Bits 24-31 : PMD offset within the PGD
-
-.macro MMU_REFILL_HANDLER handler, mmu
- .data
-1: .dword 0 ; refill_count
- ; == 0 <=> last_refill_cause is invalid
-2: .dword 0 ; last_refill_cause
- .text
- .globl \handler
- .type \handler, "function"
-\handler:
- subq 4, $sp
-; (The pipeline stalls for one cycle; $sp used as address in the next cycle.)
- move $srs, [$sp]
- subq 4, $sp
- move \mmu, $srs ; Select MMU support register bank
- move.d $acr, [$sp]
- subq 12, $sp
- move.d 1b, $acr ; Point to refill_count
- movem $r2, [$sp]
-
- test.d [$acr] ; refill_count == 0 ?
- beq 5f ; yes, last_refill_cause is invalid
- move.d $acr, $r1
-
- ; last_refill_cause is valid, investigate cause
- addq 4, $r1 ; Point to last_refill_cause
- move $s3, $r0 ; Get rw_mm_cause
- move.d [$r1], $r2 ; Get last_refill_cause
- cmp.d $r0, $r2 ; rw_mm_cause == last_refill_cause ?
- beq 6f ; yes, increment count
- moveq 1, $r2
-
- ; rw_mm_cause != last_refill_cause
- move.d $r2, [$acr] ; refill_count = 1
- move.d $r0, [$r1] ; last_refill_cause = rw_mm_cause
-
-3: ; Probably not in a loop, continue normal processing
- move.d current_pgd, $acr ; PGD
- ; Look up PMD in PGD
- lsrq 24, $r0 ; Get PMD index into PGD (bit 24-31)
- move.d [$acr], $acr ; PGD for the current process
- addi $r0.d, $acr, $acr
- move $s3, $r0 ; rw_mm_cause
- move.d [$acr], $acr ; Get PMD
- beq 8f
- ; Look up PTE in PMD
- lsrq PAGE_SHIFT, $r0
- and.w PAGE_MASK, $acr ; Remove PMD flags
- and.d 0x7ff, $r0 ; Get PTE index into PMD (bit 13-23)
- addi $r0.d, $acr, $acr
- move.d [$acr], $acr ; Get PTE
- beq 9f
- movem [$sp], $r2 ; Restore r0-r2 in delay slot
- addq 12, $sp
- ; Store in TLB
- move $acr, $s5
-4: ; Return
- move.d [$sp+], $acr
- move [$sp], $srs
- addq 4, $sp
- rete
- rfe
-
-5: ; last_refill_cause is invalid
- moveq 1, $r2
- addq 4, $r1 ; Point to last_refill_cause
- move.d $r2, [$acr] ; refill_count = 1
- move $s3, $r0 ; Get rw_mm_cause
- ba 3b ; Continue normal processing
- move.d $r0,[$r1] ; last_refill_cause = rw_mm_cause
-
-6: ; rw_mm_cause == last_refill_cause
- move.d [$acr], $r2 ; Get refill_count
- cmpq 4, $r2 ; refill_count > 4 ?
- bhi 7f ; yes
- addq 1, $r2 ; refill_count++
- ba 3b ; Continue normal processing
- move.d $r2, [$acr]
-
-7: ; refill_count > 4, error
- move.d $acr, $r0 ; Save pointer to refill_count
- clear.d [$r0] ; refill_count = 0
-
- ;; rewind the short stack
- movem [$sp], $r2 ; Restore r0-r2
- addq 12, $sp
- move.d [$sp+], $acr
- move [$sp], $srs
- addq 4, $sp
- ;; Keep it simple (slow), save all the regs.
- SAVE_ALL
- jsr __flush_tlb_all
- nop
- ba ret_from_intr ; Return
- nop
-
-8: ; PMD missing, let the mm subsystem fix it up.
- movem [$sp], $r2 ; Restore r0-r2
-9: ; PTE missing, let the mm subsystem fix it up.
- addq 12, $sp
- move.d [$sp+], $acr
- move [$sp], $srs
- addq 4, $sp
- SAVE_ALL
- move \mmu, $srs
- move.d $sp, $r11 ; regs
- clear.d $r12 ; Not a protection fault
- move.w PAGE_MASK, $acr
- move $s3, $r10 ; rw_mm_cause
- btstq 9, $r10 ; Check if write access
- smi $r13
- and.w PAGE_MASK, $r10 ; Get VPN (virtual address)
- jsr do_page_fault
- and.w $acr, $r10
- ; Return
- ba ret_from_intr
- nop
- .size \handler, . - \handler
-.endm
-
- ; This is the MMU bus fault handlers.
-
-MMU_REFILL_HANDLER i_mmu_refill, 1
-MMU_BUS_FAULT_HANDLER i_mmu_invalid, 1, 0, 0
-MMU_BUS_FAULT_HANDLER i_mmu_access, 1, 0, 0
-MMU_BUS_FAULT_HANDLER i_mmu_execute, 1, 0, 1
-MMU_REFILL_HANDLER d_mmu_refill, 2
-MMU_BUS_FAULT_HANDLER d_mmu_invalid, 2, 0, 0
-MMU_BUS_FAULT_HANDLER d_mmu_access, 2, 0, 0
-MMU_BUS_FAULT_HANDLER d_mmu_write, 2, 1, 0