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linux/arch/arm/mm/tlb-v7.S
Will Deacon 730a8128cd ARM: 7489/1: errata: fix workaround for erratum #720789 on UP systems
Commit 5a783cbc48 ("ARM: 7478/1: errata: extend workaround for erratum
 #720789") added workarounds for erratum #720789 to the range TLB
invalidation functions with the observation that the erratum only
affects SMP platforms. However, when running an SMP_ON_UP kernel on a
uniprocessor platform we must take care to preserve the ASID as the
workaround is not required.

This patch ensures that we don't set the ASID to 0 when flushing the TLB
on such a system, preserving the original behaviour with the workaround
disabled.

Cc: <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2012-08-11 09:16:00 +01:00

96 lines
2.6 KiB
ArmAsm

/*
* linux/arch/arm/mm/tlb-v7.S
*
* Copyright (C) 1997-2002 Russell King
* Modified for ARMv7 by Catalin Marinas
*
* 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/init.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
#include <asm/page.h>
#include <asm/tlbflush.h>
#include "proc-macros.S"
/*
* v7wbi_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(v7wbi_flush_user_tlb_range)
vma_vm_mm r3, r2 @ get vma->vm_mm
mmid r3, r3 @ get vm_mm->context.id
dsb
mov r0, r0, lsr #PAGE_SHIFT @ align address
mov r1, r1, lsr #PAGE_SHIFT
asid r3, r3 @ mask ASID
#ifdef CONFIG_ARM_ERRATA_720789
ALT_SMP(W(mov) r3, #0 )
ALT_UP(W(nop) )
#endif
orr r0, r3, r0, lsl #PAGE_SHIFT @ Create initial MVA
mov r1, r1, lsl #PAGE_SHIFT
1:
#ifdef CONFIG_ARM_ERRATA_720789
ALT_SMP(mcr p15, 0, r0, c8, c3, 3) @ TLB invalidate U MVA all ASID (shareable)
#else
ALT_SMP(mcr p15, 0, r0, c8, c3, 1) @ TLB invalidate U MVA (shareable)
#endif
ALT_UP(mcr p15, 0, r0, c8, c7, 1) @ TLB invalidate U MVA
add r0, r0, #PAGE_SZ
cmp r0, r1
blo 1b
dsb
mov pc, lr
ENDPROC(v7wbi_flush_user_tlb_range)
/*
* v7wbi_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(v7wbi_flush_kern_tlb_range)
dsb
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 CONFIG_ARM_ERRATA_720789
ALT_SMP(mcr p15, 0, r0, c8, c3, 3) @ TLB invalidate U MVA all ASID (shareable)
#else
ALT_SMP(mcr p15, 0, r0, c8, c3, 1) @ TLB invalidate U MVA (shareable)
#endif
ALT_UP(mcr p15, 0, r0, c8, c7, 1) @ TLB invalidate U MVA
add r0, r0, #PAGE_SZ
cmp r0, r1
blo 1b
dsb
isb
mov pc, lr
ENDPROC(v7wbi_flush_kern_tlb_range)
__INIT
/* define struct cpu_tlb_fns (see <asm/tlbflush.h> and proc-macros.S) */
define_tlb_functions v7wbi, v7wbi_tlb_flags_up, flags_smp=v7wbi_tlb_flags_smp