1
linux/arch/arm/mm/tlb-v6.S
Catalin Marinas 6a0e243069 [ARM] 3352/1: DSB required for the completion of a TLB maintenance operation
Patch from Catalin Marinas

Chapter B2.7.3 in the latest ARM ARM (with v6 information) states that
the completion of a TLB maintenance operation is only guaranteed by
the execution of a DSB (Data Syncronization Barrier, formerly Data
Write Barrier or Drain Write Buffer).

Note that a DSB is only needed in the flush_tlb_kernel_* functions
since the completion is guaranteed by a mode change (i.e. switching
back to user mode) for the flush_tlb_user_* functions.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2006-03-07 14:42:27 +00:00

94 lines
2.5 KiB
ArmAsm

/*
* linux/arch/arm/mm/tlb-v6.S
*
* Copyright (C) 1997-2002 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* ARM architecture version 6 TLB handling functions.
* These assume a split I/D TLB.
*/
#include <linux/linkage.h>
#include <asm/asm-offsets.h>
#include <asm/page.h>
#include <asm/tlbflush.h>
#include "proc-macros.S"
#define HARVARD_TLB
/*
* v6wbi_flush_user_tlb_range(start, end, vma)
*
* Invalidate a range of TLB entries in the specified address space.
*
* - start - start address (may not be aligned)
* - end - end address (exclusive, may not be aligned)
* - vma - vma_struct describing address range
*
* It is assumed that:
* - the "Invalidate single entry" instruction will invalidate
* both the I and the D TLBs on Harvard-style TLBs
*/
ENTRY(v6wbi_flush_user_tlb_range)
vma_vm_mm r3, r2 @ get vma->vm_mm
mov ip, #0
mmid r3, r3 @ get vm_mm->context.id
mcr p15, 0, ip, c7, c10, 4 @ drain write buffer
mov r0, r0, lsr #PAGE_SHIFT @ align address
mov r1, r1, lsr #PAGE_SHIFT
asid r3, r3 @ mask ASID
orr r0, r3, r0, lsl #PAGE_SHIFT @ Create initial MVA
mov r1, r1, lsl #PAGE_SHIFT
vma_vm_flags r2, r2 @ get vma->vm_flags
1:
#ifdef HARVARD_TLB
mcr p15, 0, r0, c8, c6, 1 @ TLB invalidate D MVA (was 1)
tst r2, #VM_EXEC @ Executable area ?
mcrne p15, 0, r0, c8, c5, 1 @ TLB invalidate I MVA (was 1)
#else
mcr p15, 0, r0, c8, c7, 1 @ TLB invalidate MVA (was 1)
#endif
add r0, r0, #PAGE_SZ
cmp r0, r1
blo 1b
mov pc, lr
/*
* v6wbi_flush_kern_tlb_range(start,end)
*
* Invalidate a range of kernel TLB entries
*
* - start - start address (may not be aligned)
* - end - end address (exclusive, may not be aligned)
*/
ENTRY(v6wbi_flush_kern_tlb_range)
mov r2, #0
mcr p15, 0, r2, c7, c10, 4 @ drain write buffer
mov r0, r0, lsr #PAGE_SHIFT @ align address
mov r1, r1, lsr #PAGE_SHIFT
mov r0, r0, lsl #PAGE_SHIFT
mov r1, r1, lsl #PAGE_SHIFT
1:
#ifdef HARVARD_TLB
mcr p15, 0, r0, c8, c6, 1 @ TLB invalidate D MVA
mcr p15, 0, r0, c8, c5, 1 @ TLB invalidate I MVA
#else
mcr p15, 0, r0, c8, c7, 1 @ TLB invalidate MVA
#endif
add r0, r0, #PAGE_SZ
cmp r0, r1
blo 1b
mcr p15, 0, r2, c7, c10, 4 @ data synchronization barrier
mov pc, lr
.section ".text.init", #alloc, #execinstr
.type v6wbi_tlb_fns, #object
ENTRY(v6wbi_tlb_fns)
.long v6wbi_flush_user_tlb_range
.long v6wbi_flush_kern_tlb_range
.long v6wbi_tlb_flags
.size v6wbi_tlb_fns, . - v6wbi_tlb_fns