linux/arch/arm/mm/proc-v7.S
Russell King 4b46d64165 ARM: ensure initial page tables are setup for SMP systems
Mapping the same memory using two different attributes (memory
type, shareability, cacheability) is unpredictable.  During boot,
we encounter a situation when we're updating the kernel's page
tables which can lead to dirty cache lines existing in the cache
which are subsequently missed.  This causes stack corruption,
and therefore a crash.

Therefore, ensure that the shared and cacheability settings
matches the configuration that will be used later; this together
with the restriction in early_cachepolicy() ensures that we won't
create a mismatch during boot.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2009-11-02 16:59:59 +00:00

348 lines
8.7 KiB
ArmAsm

/*
* linux/arch/arm/mm/proc-v7.S
*
* Copyright (C) 2001 Deep Blue Solutions Ltd.
*
* 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.
*
* This is the "shell" of the ARMv7 processor support.
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
#include <asm/hwcap.h>
#include <asm/pgtable-hwdef.h>
#include <asm/pgtable.h>
#include "proc-macros.S"
#define TTB_S (1 << 1)
#define TTB_RGN_NC (0 << 3)
#define TTB_RGN_OC_WBWA (1 << 3)
#define TTB_RGN_OC_WT (2 << 3)
#define TTB_RGN_OC_WB (3 << 3)
#define TTB_NOS (1 << 5)
#define TTB_IRGN_NC ((0 << 0) | (0 << 6))
#define TTB_IRGN_WBWA ((0 << 0) | (1 << 6))
#define TTB_IRGN_WT ((1 << 0) | (0 << 6))
#define TTB_IRGN_WB ((1 << 0) | (1 << 6))
#ifndef CONFIG_SMP
/* PTWs cacheable, inner WB not shareable, outer WB not shareable */
#define TTB_FLAGS TTB_IRGN_WB|TTB_RGN_OC_WB
#define PMD_FLAGS PMD_SECT_WB
#else
/* PTWs cacheable, inner WBWA shareable, outer WBWA not shareable */
#define TTB_FLAGS TTB_IRGN_WBWA|TTB_S|TTB_NOS|TTB_RGN_OC_WBWA
#define PMD_FLAGS PMD_SECT_WBWA|PMD_SECT_S
#endif
ENTRY(cpu_v7_proc_init)
mov pc, lr
ENDPROC(cpu_v7_proc_init)
ENTRY(cpu_v7_proc_fin)
mov pc, lr
ENDPROC(cpu_v7_proc_fin)
/*
* cpu_v7_reset(loc)
*
* Perform a soft reset of the system. Put the CPU into the
* same state as it would be if it had been reset, and branch
* to what would be the reset vector.
*
* - loc - location to jump to for soft reset
*
* It is assumed that:
*/
.align 5
ENTRY(cpu_v7_reset)
mov pc, r0
ENDPROC(cpu_v7_reset)
/*
* cpu_v7_do_idle()
*
* Idle the processor (eg, wait for interrupt).
*
* IRQs are already disabled.
*/
ENTRY(cpu_v7_do_idle)
dsb @ WFI may enter a low-power mode
wfi
mov pc, lr
ENDPROC(cpu_v7_do_idle)
ENTRY(cpu_v7_dcache_clean_area)
#ifndef TLB_CAN_READ_FROM_L1_CACHE
dcache_line_size r2, r3
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, r2
subs r1, r1, r2
bhi 1b
dsb
#endif
mov pc, lr
ENDPROC(cpu_v7_dcache_clean_area)
/*
* cpu_v7_switch_mm(pgd_phys, tsk)
*
* Set the translation table base pointer to be pgd_phys
*
* - pgd_phys - physical address of new TTB
*
* It is assumed that:
* - we are not using split page tables
*/
ENTRY(cpu_v7_switch_mm)
#ifdef CONFIG_MMU
mov r2, #0
ldr r1, [r1, #MM_CONTEXT_ID] @ get mm->context.id
orr r0, r0, #TTB_FLAGS
#ifdef CONFIG_ARM_ERRATA_430973
mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
#endif
mcr p15, 0, r2, c13, c0, 1 @ set reserved context ID
isb
1: mcr p15, 0, r0, c2, c0, 0 @ set TTB 0
isb
mcr p15, 0, r1, c13, c0, 1 @ set context ID
isb
#endif
mov pc, lr
ENDPROC(cpu_v7_switch_mm)
/*
* cpu_v7_set_pte_ext(ptep, pte)
*
* Set a level 2 translation table entry.
*
* - ptep - pointer to level 2 translation table entry
* (hardware version is stored at -1024 bytes)
* - pte - PTE value to store
* - ext - value for extended PTE bits
*/
ENTRY(cpu_v7_set_pte_ext)
#ifdef CONFIG_MMU
ARM( str r1, [r0], #-2048 ) @ linux version
THUMB( str r1, [r0] ) @ linux version
THUMB( sub r0, r0, #2048 )
bic r3, r1, #0x000003f0
bic r3, r3, #PTE_TYPE_MASK
orr r3, r3, r2
orr r3, r3, #PTE_EXT_AP0 | 2
tst r1, #1 << 4
orrne r3, r3, #PTE_EXT_TEX(1)
tst r1, #L_PTE_WRITE
tstne r1, #L_PTE_DIRTY
orreq r3, r3, #PTE_EXT_APX
tst r1, #L_PTE_USER
orrne r3, r3, #PTE_EXT_AP1
tstne r3, #PTE_EXT_APX
bicne r3, r3, #PTE_EXT_APX | PTE_EXT_AP0
tst r1, #L_PTE_EXEC
orreq r3, r3, #PTE_EXT_XN
tst r1, #L_PTE_YOUNG
tstne r1, #L_PTE_PRESENT
moveq r3, #0
str r3, [r0]
mcr p15, 0, r0, c7, c10, 1 @ flush_pte
#endif
mov pc, lr
ENDPROC(cpu_v7_set_pte_ext)
cpu_v7_name:
.ascii "ARMv7 Processor"
.align
__INIT
/*
* __v7_setup
*
* Initialise TLB, Caches, and MMU state ready to switch the MMU
* on. Return in r0 the new CP15 C1 control register setting.
*
* We automatically detect if we have a Harvard cache, and use the
* Harvard cache control instructions insead of the unified cache
* control instructions.
*
* This should be able to cover all ARMv7 cores.
*
* It is assumed that:
* - cache type register is implemented
*/
__v7_setup:
#ifdef CONFIG_SMP
mrc p15, 0, r0, c1, c0, 1 @ Enable SMP/nAMP mode and
orr r0, r0, #(1 << 6) | (1 << 0) @ TLB ops broadcasting
mcr p15, 0, r0, c1, c0, 1
#endif
adr r12, __v7_setup_stack @ the local stack
stmia r12, {r0-r5, r7, r9, r11, lr}
bl v7_flush_dcache_all
ldmia r12, {r0-r5, r7, r9, r11, lr}
mrc p15, 0, r0, c0, c0, 0 @ read main ID register
and r10, r0, #0xff000000 @ ARM?
teq r10, #0x41000000
bne 2f
and r5, r0, #0x00f00000 @ variant
and r6, r0, #0x0000000f @ revision
orr r0, r6, r5, lsr #20-4 @ combine variant and revision
#ifdef CONFIG_ARM_ERRATA_430973
teq r5, #0x00100000 @ only present in r1p*
mrceq p15, 0, r10, c1, c0, 1 @ read aux control register
orreq r10, r10, #(1 << 6) @ set IBE to 1
mcreq p15, 0, r10, c1, c0, 1 @ write aux control register
#endif
#ifdef CONFIG_ARM_ERRATA_458693
teq r0, #0x20 @ only present in r2p0
mrceq p15, 0, r10, c1, c0, 1 @ read aux control register
orreq r10, r10, #(1 << 5) @ set L1NEON to 1
orreq r10, r10, #(1 << 9) @ set PLDNOP to 1
mcreq p15, 0, r10, c1, c0, 1 @ write aux control register
#endif
#ifdef CONFIG_ARM_ERRATA_460075
teq r0, #0x20 @ only present in r2p0
mrceq p15, 1, r10, c9, c0, 2 @ read L2 cache aux ctrl register
tsteq r10, #1 << 22
orreq r10, r10, #(1 << 22) @ set the Write Allocate disable bit
mcreq p15, 1, r10, c9, c0, 2 @ write the L2 cache aux ctrl register
#endif
2: mov r10, #0
#ifdef HARVARD_CACHE
mcr p15, 0, r10, c7, c5, 0 @ I+BTB cache invalidate
#endif
dsb
#ifdef CONFIG_MMU
mcr p15, 0, r10, c8, c7, 0 @ invalidate I + D TLBs
mcr p15, 0, r10, c2, c0, 2 @ TTB control register
orr r4, r4, #TTB_FLAGS
mcr p15, 0, r4, c2, c0, 1 @ load TTB1
mov r10, #0x1f @ domains 0, 1 = manager
mcr p15, 0, r10, c3, c0, 0 @ load domain access register
/*
* Memory region attributes with SCTLR.TRE=1
*
* n = TEX[0],C,B
* TR = PRRR[2n+1:2n] - memory type
* IR = NMRR[2n+1:2n] - inner cacheable property
* OR = NMRR[2n+17:2n+16] - outer cacheable property
*
* n TR IR OR
* UNCACHED 000 00
* BUFFERABLE 001 10 00 00
* WRITETHROUGH 010 10 10 10
* WRITEBACK 011 10 11 11
* reserved 110
* WRITEALLOC 111 10 01 01
* DEV_SHARED 100 01
* DEV_NONSHARED 100 01
* DEV_WC 001 10
* DEV_CACHED 011 10
*
* Other attributes:
*
* DS0 = PRRR[16] = 0 - device shareable property
* DS1 = PRRR[17] = 1 - device shareable property
* NS0 = PRRR[18] = 0 - normal shareable property
* NS1 = PRRR[19] = 1 - normal shareable property
* NOS = PRRR[24+n] = 1 - not outer shareable
*/
ldr r5, =0xff0a81a8 @ PRRR
ldr r6, =0x40e040e0 @ NMRR
mcr p15, 0, r5, c10, c2, 0 @ write PRRR
mcr p15, 0, r6, c10, c2, 1 @ write NMRR
#endif
adr r5, v7_crval
ldmia r5, {r5, r6}
#ifdef CONFIG_CPU_ENDIAN_BE8
orr r6, r6, #1 << 25 @ big-endian page tables
#endif
mrc p15, 0, r0, c1, c0, 0 @ read control register
bic r0, r0, r5 @ clear bits them
orr r0, r0, r6 @ set them
THUMB( orr r0, r0, #1 << 30 ) @ Thumb exceptions
mov pc, lr @ return to head.S:__ret
ENDPROC(__v7_setup)
/* AT
* TFR EV X F I D LR S
* .EEE ..EE PUI. .T.T 4RVI ZWRS BLDP WCAM
* rxxx rrxx xxx0 0101 xxxx xxxx x111 xxxx < forced
* 1 0 110 0011 1100 .111 1101 < we want
*/
.type v7_crval, #object
v7_crval:
crval clear=0x0120c302, mmuset=0x10c03c7d, ucset=0x00c01c7c
__v7_setup_stack:
.space 4 * 11 @ 11 registers
.type v7_processor_functions, #object
ENTRY(v7_processor_functions)
.word v7_early_abort
.word v7_pabort
.word cpu_v7_proc_init
.word cpu_v7_proc_fin
.word cpu_v7_reset
.word cpu_v7_do_idle
.word cpu_v7_dcache_clean_area
.word cpu_v7_switch_mm
.word cpu_v7_set_pte_ext
.size v7_processor_functions, . - v7_processor_functions
.type cpu_arch_name, #object
cpu_arch_name:
.asciz "armv7"
.size cpu_arch_name, . - cpu_arch_name
.type cpu_elf_name, #object
cpu_elf_name:
.asciz "v7"
.size cpu_elf_name, . - cpu_elf_name
.align
.section ".proc.info.init", #alloc, #execinstr
/*
* Match any ARMv7 processor core.
*/
.type __v7_proc_info, #object
__v7_proc_info:
.long 0x000f0000 @ Required ID value
.long 0x000f0000 @ Mask for ID
.long PMD_TYPE_SECT | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ | \
PMD_FLAGS
.long PMD_TYPE_SECT | \
PMD_SECT_XN | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ
b __v7_setup
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP
.long cpu_v7_name
.long v7_processor_functions
.long v7wbi_tlb_fns
.long v6_user_fns
.long v7_cache_fns
.size __v7_proc_info, . - __v7_proc_info