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mmu.S
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/*
* linux/arch/m32r/mm/mmu.S
*
* Copyright (C) 2001 by Hiroyuki Kondo
*/
/* $Id: mmu.S,v 1.15 2004/03/16 02:56:27 takata Exp $ */
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/smp.h>
.text
#ifdef CONFIG_MMU
#include <asm/mmu_context.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/m32r.h>
/*
* TLB Miss Exception handler
*/
.balign 16
ENTRY(tme_handler)
.global tlb_entry_i_dat
.global tlb_entry_d_dat
SWITCH_TO_KERNEL_STACK
#if defined(CONFIG_ISA_M32R2)
st r0, @-sp
st r1, @-sp
st r2, @-sp
st r3, @-sp
seth r3, #high(MMU_REG_BASE)
ld r1, @(MESTS_offset, r3) ; r1: status (MESTS reg.)
ld r0, @(MDEVP_offset, r3) ; r0: PFN + ASID (MDEVP reg.)
st r1, @(MESTS_offset, r3) ; clear status (MESTS reg.)
and3 r1, r1, #(MESTS_IT)
bnez r1, 1f ; instruction TLB miss?
;; data TLB miss
;; input
;; r0: PFN + ASID (MDEVP reg.)
;; r1 - r3: free
;; output
;; r0: PFN + ASID
;; r1: TLB entry base address
;; r2: &tlb_entry_{i|d}_dat
;; r3: free
#ifndef CONFIG_SMP
seth r2, #high(tlb_entry_d_dat)
or3 r2, r2, #low(tlb_entry_d_dat)
#else /* CONFIG_SMP */
ldi r1, #-8192
seth r2, #high(tlb_entry_d_dat)
or3 r2, r2, #low(tlb_entry_d_dat)
and r1, sp
ld r1, @(16, r1) ; current_thread_info->cpu
slli r1, #2
add r2, r1
#endif /* !CONFIG_SMP */
seth r1, #high(DTLB_BASE)
or3 r1, r1, #low(DTLB_BASE)
bra 2f
.balign 16
.fillinsn
1:
;; instrucntion TLB miss
;; input
;; r0: MDEVP reg. (included ASID)
;; r1 - r3: free
;; output
;; r0: PFN + ASID
;; r1: TLB entry base address
;; r2: &tlb_entry_{i|d}_dat
;; r3: free
ldi r3, #-4096
and3 r0, r0, #(MMU_CONTEXT_ASID_MASK)
mvfc r1, bpc
and r1, r3
or r0, r1 ; r0: PFN + ASID
#ifndef CONFIG_SMP
seth r2, #high(tlb_entry_i_dat)
or3 r2, r2, #low(tlb_entry_i_dat)
#else /* CONFIG_SMP */
ldi r1, #-8192
seth r2, #high(tlb_entry_i_dat)
or3 r2, r2, #low(tlb_entry_i_dat)
and r1, sp
ld r1, @(16, r1) ; current_thread_info->cpu
slli r1, #2
add r2, r1
#endif /* !CONFIG_SMP */
seth r1, #high(ITLB_BASE)
or3 r1, r1, #low(ITLB_BASE)
.fillinsn
2:
;; select TLB entry
;; input
;; r0: PFN + ASID
;; r1: TLB entry base address
;; r2: &tlb_entry_{i|d}_dat
;; r3: free
;; output
;; r0: PFN + ASID
;; r1: TLB entry address
;; r2, r3: free
#ifdef CONFIG_ISA_DUAL_ISSUE
ld r3, @r2 || srli r1, #3
#else
ld r3, @r2
srli r1, #3
#endif
add r1, r3
; tlb_entry_{d|i}_dat++;
addi r3, #1
and3 r3, r3, #(NR_TLB_ENTRIES - 1)
#ifdef CONFIG_ISA_DUAL_ISSUE
st r3, @r2 || slli r1, #3
#else
st r3, @r2
slli r1, #3
#endif
;; load pte
;; input
;; r0: PFN + ASID
;; r1: TLB entry address
;; r2, r3: free
;; output
;; r0: PFN + ASID
;; r1: TLB entry address
;; r2: pte_data
;; r3: free
; pgd = *(unsigned long *)MPTB;
ld24 r2, #(-MPTB - 1)
srl3 r3, r0, #22
#ifdef CONFIG_ISA_DUAL_ISSUE
not r2, r2 || slli r3, #2 ; r3: pgd offset
#else
not r2, r2
slli r3, #2
#endif
ld r2, @r2 ; r2: pgd base addr (MPTB reg.)
or r3, r2 ; r3: pmd addr
; pmd = pmd_offset(pgd, address);
ld r3, @r3 ; r3: pmd data
ldi r2, #-4096
beqz r3, 3f ; pmd_none(*pmd) ?
; pte = pte_offset(pmd, address);
and r2, r3 ; r2: pte base addr
srl3 r3, r0, #10
and3 r3, r3, #0xffc ; r3: pte offset
or r3, r2
seth r2, #0x8000
or r3, r2 ; r3: pte addr
; pte_data = (unsigned long)pte_val(*pte);
ld r2, @r3 ; r2: pte data
or3 r2, r2, #2 ; _PAGE_PRESENT(=2)
.fillinsn
5:
;; set tlb
;; input
;; r0: PFN + ASID
;; r1: TLB entry address
;; r2: pte_data
;; r3: free
st r0, @r1 ; set_tlb_tag(entry++, address);
st r2, @+r1 ; set_tlb_data(entry, pte_data);
.fillinsn
6:
ld r3, @sp+
ld r2, @sp+
ld r1, @sp+
ld r0, @sp+
rte
.fillinsn
3:
;; error
;; input
;; r0: PFN + ASID
;; r1: TLB entry address
;; r2, r3: free
;; output
;; r0: PFN + ASID
;; r1: TLB entry address
;; r2: pte_data
;; r3: free
#ifdef CONFIG_ISA_DUAL_ISSUE
bra 5b || ldi r2, #2
#else
ldi r2, #2 ; r2: pte_data = 0 | _PAGE_PRESENT(=2)
bra 5b
#endif
#elif defined (CONFIG_ISA_M32R)
st sp, @-sp
st r0, @-sp
st r1, @-sp
st r2, @-sp
st r3, @-sp
st r4, @-sp
seth r3, #high(MMU_REG_BASE)
ld r0, @(MDEVA_offset,r3) ; r0: address (MDEVA reg.)
mvfc r2, bpc ; r2: bpc
ld r1, @(MESTS_offset,r3) ; r1: status (MESTS reg.)
st r1, @(MESTS_offset,r3) ; clear status (MESTS reg.)
and3 r1, r1, #(MESTS_IT)
beqz r1, 1f ; data TLB miss?
;; instrucntion TLB miss
mv r0, r2 ; address = bpc;
; entry = (unsigned long *)ITLB_BASE+tlb_entry_i*2;
seth r3, #shigh(tlb_entry_i_dat)
ld r4, @(low(tlb_entry_i_dat),r3)
sll3 r2, r4, #3
seth r1, #high(ITLB_BASE)
or3 r1, r1, #low(ITLB_BASE)
add r2, r1 ; r2: entry
addi r4, #1 ; tlb_entry_i++;
and3 r4, r4, #(NR_TLB_ENTRIES-1)
st r4, @(low(tlb_entry_i_dat),r3)
bra 2f
.fillinsn
1:
;; data TLB miss
; entry = (unsigned long *)DTLB_BASE+tlb_entry_d*2;
seth r3, #shigh(tlb_entry_d_dat)
ld r4, @(low(tlb_entry_d_dat),r3)
sll3 r2, r4, #3
seth r1, #high(DTLB_BASE)
or3 r1, r1, #low(DTLB_BASE)
add r2, r1 ; r2: entry
addi r4, #1 ; tlb_entry_d++;
and3 r4, r4, #(NR_TLB_ENTRIES-1)
st r4, @(low(tlb_entry_d_dat),r3)
.fillinsn
2:
;; load pte
; r0: address, r2: entry
; r1,r3,r4: (free)
; pgd = *(unsigned long *)MPTB;
ld24 r1, #(-MPTB-1)
not r1, r1
ld r1, @r1
srl3 r4, r0, #22
sll3 r3, r4, #2
add r3, r1 ; r3: pgd
; pmd = pmd_offset(pgd, address);
ld r1, @r3 ; r1: pmd
beqz r1, 3f ; pmd_none(*pmd) ?
;
and3 r1, r1, #0xeff
ldi r4, #611 ; _KERNPG_TABLE(=611)
beq r1, r4, 4f ; !pmd_bad(*pmd) ?
.fillinsn
3:
ldi r1, #0 ; r1: pte_data = 0
bra 5f
.fillinsn
4:
; pte = pte_offset(pmd, address);
ld r4, @r3 ; r4: pte
ldi r3, #-4096
and r4, r3
srl3 r3, r0, #10
and3 r3, r3, #0xffc
add r4, r3
seth r3, #0x8000
add r4, r3 ; r4: pte
; pte_data = (unsigned long)pte_val(*pte);
ld r1, @r4 ; r1: pte_data
.fillinsn
;; set tlb
; r0: address, r1: pte_data, r2: entry
; r3,r4: (free)
5:
ldi r3, #-4096 ; set_tlb_tag(entry++, address);
and r3, r0
seth r4, #shigh(MASID)
ld r4, @(low(MASID),r4) ; r4: MASID
and3 r4, r4, #(MMU_CONTEXT_ASID_MASK)
or r3, r4
st r3, @r2
or3 r4, r1, #2 ; _PAGE_PRESENT(=2)
st r4, @(4,r2) ; set_tlb_data(entry, pte_data);
ld r4, @sp+
ld r3, @sp+
ld r2, @sp+
ld r1, @sp+
ld r0, @sp+
ld sp, @sp+
rte
#else
#error unknown isa configuration
#endif
ENTRY(init_tlb)
;; Set MMU Register
seth r0, #high(MMU_REG_BASE) ; Set MMU_REG_BASE higher
or3 r0, r0, #low(MMU_REG_BASE) ; Set MMU_REG_BASE lower
ldi r1, #0
st r1, @(MPSZ_offset,r0) ; Set MPSZ Reg(Page size 4KB:0 16KB:1 64KB:2)
ldi r1, #0
st r1, @(MASID_offset,r0) ; Set ASID Zero
;; Set TLB
seth r0, #high(ITLB_BASE) ; Set ITLB_BASE higher
or3 r0, r0, #low(ITLB_BASE) ; Set ITLB_BASE lower
seth r1, #high(DTLB_BASE) ; Set DTLB_BASE higher
or3 r1, r1, #low(DTLB_BASE) ; Set DTLB_BASE lower
ldi r2, #0
ldi r3, #NR_TLB_ENTRIES
addi r0, #-4
addi r1, #-4
clear_tlb:
st r2, @+r0 ; VPA <- 0
st r2, @+r0 ; PPA <- 0
st r2, @+r1 ; VPA <- 0
st r2, @+r1 ; PPA <- 0
addi r3, #-1
bnez r3, clear_tlb
;;
jmp r14
ENTRY(m32r_itlb_entrys)
ENTRY(m32r_otlb_entrys)
#endif /* CONFIG_MMU */
.end