linux/arch/arm/mm/proc-v7.S
Russell King 1aede681ac ARM: pm: no need to save/restore context ID register
There is no need to save and restore the context ID register on ARMv6
and ARMv7 with a temporary page table as we write the context ID
register when we switch back to the real page tables for the thread.

Moreover, the temporary page tables do not contain any non-global
mappings, so the context ID value should not be used.  To be safe,
initialize the register to a reserved context ID value.

Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Shawn Guo <shawn.guo@linaro.org>
Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-09-20 23:33:40 +01:00

494 lines
13 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))
/* PTWs cacheable, inner WB not shareable, outer WB not shareable */
#define TTB_FLAGS_UP TTB_IRGN_WB|TTB_RGN_OC_WB
#define PMD_FLAGS_UP PMD_SECT_WB
/* PTWs cacheable, inner WBWA shareable, outer WBWA not shareable */
#define TTB_FLAGS_SMP TTB_IRGN_WBWA|TTB_S|TTB_NOS|TTB_RGN_OC_WBWA
#define PMD_FLAGS_SMP PMD_SECT_WBWA|PMD_SECT_S
ENTRY(cpu_v7_proc_init)
mov pc, lr
ENDPROC(cpu_v7_proc_init)
ENTRY(cpu_v7_proc_fin)
mrc p15, 0, r0, c1, c0, 0 @ ctrl register
bic r0, r0, #0x1000 @ ...i............
bic r0, r0, #0x0006 @ .............ca.
mcr p15, 0, r0, c1, c0, 0 @ disable caches
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
*
* This code must be executed using a flat identity mapping with
* caches disabled.
*/
.align 5
ENTRY(cpu_v7_reset)
mrc p15, 0, r1, c1, c0, 0 @ ctrl register
bic r1, r1, #0x1 @ ...............m
THUMB( bic r1, r1, #1 << 30 ) @ SCTLR.TE (Thumb exceptions)
mcr p15, 0, r1, c1, c0, 0 @ disable MMU
isb
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
ALT_SMP(orr r0, r0, #TTB_FLAGS_SMP)
ALT_UP(orr r0, r0, #TTB_FLAGS_UP)
#ifdef CONFIG_ARM_ERRATA_430973
mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
#endif
#ifdef CONFIG_ARM_ERRATA_754322
dsb
#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
#ifdef CONFIG_ARM_ERRATA_754322
dsb
#endif
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 +2048 bytes)
* - pte - PTE value to store
* - ext - value for extended PTE bits
*/
ENTRY(cpu_v7_set_pte_ext)
#ifdef CONFIG_MMU
str r1, [r0] @ linux version
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)
eor r1, r1, #L_PTE_DIRTY
tst r1, #L_PTE_RDONLY | L_PTE_DIRTY
orrne r3, r3, #PTE_EXT_APX
tst r1, #L_PTE_USER
orrne r3, r3, #PTE_EXT_AP1
#ifdef CONFIG_CPU_USE_DOMAINS
@ allow kernel read/write access to read-only user pages
tstne r3, #PTE_EXT_APX
bicne r3, r3, #PTE_EXT_APX | PTE_EXT_AP0
#endif
tst r1, #L_PTE_XN
orrne r3, r3, #PTE_EXT_XN
tst r1, #L_PTE_YOUNG
tstne r1, #L_PTE_PRESENT
moveq r3, #0
ARM( str r3, [r0, #2048]! )
THUMB( add r0, r0, #2048 )
THUMB( str r3, [r0] )
mcr p15, 0, r0, c7, c10, 1 @ flush_pte
#endif
mov pc, lr
ENDPROC(cpu_v7_set_pte_ext)
string cpu_v7_name, "ARMv7 Processor"
.align
/*
* 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
*/
.equ PRRR, 0xff0a81a8
.equ NMRR, 0x40e040e0
/* Suspend/resume support: derived from arch/arm/mach-s5pv210/sleep.S */
.globl cpu_v7_suspend_size
.equ cpu_v7_suspend_size, 4 * 7
#ifdef CONFIG_PM_SLEEP
ENTRY(cpu_v7_do_suspend)
stmfd sp!, {r4 - r10, lr}
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
mrc p15, 0, r5, c13, c0, 3 @ User r/o thread ID
stmia r0!, {r4 - r5}
mrc p15, 0, r6, c3, c0, 0 @ Domain ID
mrc p15, 0, r7, c2, c0, 1 @ TTB 1
mrc p15, 0, r8, c1, c0, 0 @ Control register
mrc p15, 0, r9, c1, c0, 1 @ Auxiliary control register
mrc p15, 0, r10, c1, c0, 2 @ Co-processor access control
stmia r0, {r6 - r10}
ldmfd sp!, {r4 - r10, pc}
ENDPROC(cpu_v7_do_suspend)
ENTRY(cpu_v7_do_resume)
mov ip, #0
mcr p15, 0, ip, c8, c7, 0 @ invalidate TLBs
mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcr p15, 0, ip, c13, c0, 1 @ set reserved context ID
ldmia r0!, {r4 - r5}
mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
mcr p15, 0, r5, c13, c0, 3 @ User r/o thread ID
ldmia r0, {r6 - r10}
mcr p15, 0, r6, c3, c0, 0 @ Domain ID
ALT_SMP(orr r1, r1, #TTB_FLAGS_SMP)
ALT_UP(orr r1, r1, #TTB_FLAGS_UP)
mcr p15, 0, r1, c2, c0, 0 @ TTB 0
mcr p15, 0, r7, c2, c0, 1 @ TTB 1
mcr p15, 0, ip, c2, c0, 2 @ TTB control register
mrc p15, 0, r4, c1, c0, 1 @ Read Auxiliary control register
teq r4, r9 @ Is it already set?
mcrne p15, 0, r9, c1, c0, 1 @ No, so write it
mcr p15, 0, r10, c1, c0, 2 @ Co-processor access control
ldr r4, =PRRR @ PRRR
ldr r5, =NMRR @ NMRR
mcr p15, 0, r4, c10, c2, 0 @ write PRRR
mcr p15, 0, r5, c10, c2, 1 @ write NMRR
isb
dsb
mov r0, r8 @ control register
b cpu_resume_mmu
ENDPROC(cpu_v7_do_resume)
#endif
__CPUINIT
/*
* __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_ca5mp_setup:
__v7_ca9mp_setup:
mov r10, #(1 << 0) @ TLB ops broadcasting
b 1f
__v7_ca15mp_setup:
mov r10, #0
1:
#ifdef CONFIG_SMP
ALT_SMP(mrc p15, 0, r0, c1, c0, 1)
ALT_UP(mov r0, #(1 << 6)) @ fake it for UP
tst r0, #(1 << 6) @ SMP/nAMP mode enabled?
orreq r0, r0, #(1 << 6) @ Enable SMP/nAMP mode
orreq r0, r0, r10 @ Enable CPU-specific SMP bits
mcreq p15, 0, r0, c1, c0, 1
#endif
__v7_setup:
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 3f
and r5, r0, #0x00f00000 @ variant
and r6, r0, #0x0000000f @ revision
orr r6, r6, r5, lsr #20-4 @ combine variant and revision
ubfx r0, r0, #4, #12 @ primary part number
/* Cortex-A8 Errata */
ldr r10, =0x00000c08 @ Cortex-A8 primary part number
teq r0, r10
bne 2f
#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 r6, #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 r6, #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
b 3f
/* Cortex-A9 Errata */
2: ldr r10, =0x00000c09 @ Cortex-A9 primary part number
teq r0, r10
bne 3f
#ifdef CONFIG_ARM_ERRATA_742230
cmp r6, #0x22 @ only present up to r2p2
mrcle p15, 0, r10, c15, c0, 1 @ read diagnostic register
orrle r10, r10, #1 << 4 @ set bit #4
mcrle p15, 0, r10, c15, c0, 1 @ write diagnostic register
#endif
#ifdef CONFIG_ARM_ERRATA_742231
teq r6, #0x20 @ present in r2p0
teqne r6, #0x21 @ present in r2p1
teqne r6, #0x22 @ present in r2p2
mrceq p15, 0, r10, c15, c0, 1 @ read diagnostic register
orreq r10, r10, #1 << 12 @ set bit #12
orreq r10, r10, #1 << 22 @ set bit #22
mcreq p15, 0, r10, c15, c0, 1 @ write diagnostic register
#endif
#ifdef CONFIG_ARM_ERRATA_743622
teq r6, #0x20 @ present in r2p0
teqne r6, #0x21 @ present in r2p1
teqne r6, #0x22 @ present in r2p2
mrceq p15, 0, r10, c15, c0, 1 @ read diagnostic register
orreq r10, r10, #1 << 6 @ set bit #6
mcreq p15, 0, r10, c15, c0, 1 @ write diagnostic register
#endif
#ifdef CONFIG_ARM_ERRATA_751472
cmp r6, #0x30 @ present prior to r3p0
mrclt p15, 0, r10, c15, c0, 1 @ read diagnostic register
orrlt r10, r10, #1 << 11 @ set bit #11
mcrlt p15, 0, r10, c15, c0, 1 @ write diagnostic register
#endif
3: 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
ALT_SMP(orr r4, r4, #TTB_FLAGS_SMP)
ALT_UP(orr r4, r4, #TTB_FLAGS_UP)
ALT_SMP(orr r8, r8, #TTB_FLAGS_SMP)
ALT_UP(orr r8, r8, #TTB_FLAGS_UP)
mcr p15, 0, r8, c2, c0, 1 @ load TTB1
ldr r5, =PRRR @ PRRR
ldr r6, =NMRR @ 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
#ifdef CONFIG_SWP_EMULATE
orr r5, r5, #(1 << 10) @ set SW bit in "clear"
bic r6, r6, #(1 << 10) @ clear it in "mmuset"
#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
__INITDATA
@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
define_processor_functions v7, dabort=v7_early_abort, pabort=v7_pabort, suspend=1
.section ".rodata"
string cpu_arch_name, "armv7"
string cpu_elf_name, "v7"
.align
.section ".proc.info.init", #alloc, #execinstr
/*
* Standard v7 proc info content
*/
.macro __v7_proc initfunc, mm_mmuflags = 0, io_mmuflags = 0, hwcaps = 0
ALT_SMP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | \
PMD_FLAGS_SMP | \mm_mmuflags)
ALT_UP(.long PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | \
PMD_FLAGS_UP | \mm_mmuflags)
.long PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ | \io_mmuflags
W(b) \initfunc
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_SWP | HWCAP_HALF | HWCAP_THUMB | HWCAP_FAST_MULT | \
HWCAP_EDSP | HWCAP_TLS | \hwcaps
.long cpu_v7_name
.long v7_processor_functions
.long v7wbi_tlb_fns
.long v6_user_fns
.long v7_cache_fns
.endm
/*
* ARM Ltd. Cortex A5 processor.
*/
.type __v7_ca5mp_proc_info, #object
__v7_ca5mp_proc_info:
.long 0x410fc050
.long 0xff0ffff0
__v7_proc __v7_ca5mp_setup
.size __v7_ca5mp_proc_info, . - __v7_ca5mp_proc_info
/*
* ARM Ltd. Cortex A9 processor.
*/
.type __v7_ca9mp_proc_info, #object
__v7_ca9mp_proc_info:
.long 0x410fc090
.long 0xff0ffff0
__v7_proc __v7_ca9mp_setup
.size __v7_ca9mp_proc_info, . - __v7_ca9mp_proc_info
/*
* ARM Ltd. Cortex A15 processor.
*/
.type __v7_ca15mp_proc_info, #object
__v7_ca15mp_proc_info:
.long 0x410fc0f0
.long 0xff0ffff0
__v7_proc __v7_ca15mp_setup, hwcaps = HWCAP_IDIV
.size __v7_ca15mp_proc_info, . - __v7_ca15mp_proc_info
/*
* Match any ARMv7 processor core.
*/
.type __v7_proc_info, #object
__v7_proc_info:
.long 0x000f0000 @ Required ID value
.long 0x000f0000 @ Mask for ID
__v7_proc __v7_setup
.size __v7_proc_info, . - __v7_proc_info