/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/mm/proc-v6.S
*
* Copyright (C) 2001 Deep Blue Solutions Ltd.
* Modified by Catalin Marinas for noMMU support
*
* This is the "shell" of the ARMv6 processor support.
*/
#include <linux/init.h>
#include <linux/linkage.h>
#include <linux/pgtable.h>
#include <asm/assembler.h>
#include <asm/asm-offsets.h>
#include <asm/hwcap.h>
#include <asm/pgtable-hwdef.h>
#include "proc-macros.S"
#define D_CACHE_LINE_SIZE 32
#define TTB_C (1 << 0)
#define TTB_S (1 << 1)
#define TTB_IMP (1 << 2)
#define TTB_RGN_NC (0 << 3)
#define TTB_RGN_WBWA (1 << 3)
#define TTB_RGN_WT (2 << 3)
#define TTB_RGN_WB (3 << 3)
#define TTB_FLAGS_UP TTB_RGN_WBWA
#define PMD_FLAGS_UP PMD_SECT_WB
#define TTB_FLAGS_SMP TTB_RGN_WBWA|TTB_S
#define PMD_FLAGS_SMP PMD_SECT_WBWA|PMD_SECT_S
.arch armv6
ENTRY(cpu_v6_proc_init)
ret lr
ENTRY(cpu_v6_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
ret lr
/*
* cpu_v6_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
*/
.align 5
.pushsection .idmap.text, "ax"
ENTRY(cpu_v6_reset)
mrc p15, 0, r1, c1, c0, 0 @ ctrl register
bic r1, r1, #0x1 @ ...............m
mcr p15, 0, r1, c1, c0, 0 @ disable MMU
mov r1, #0
mcr p15, 0, r1, c7, c5, 4 @ ISB
ret r0
ENDPROC(cpu_v6_reset)
.popsection
/*
* cpu_v6_do_idle()
*
* Idle the processor (eg, wait for interrupt).
*
* IRQs are already disabled.
*/
ENTRY(cpu_v6_do_idle)
mov r1, #0
mcr p15, 0, r1, c7, c10, 4 @ DWB - WFI may enter a low-power mode
mcr p15, 0, r1, c7, c0, 4 @ wait for interrupt
ret lr
ENTRY(cpu_v6_dcache_clean_area)
1: mcr p15, 0, r0, c7, c10, 1 @ clean D entry
add r0, r0, #D_CACHE_LINE_SIZE
subs r1, r1, #D_CACHE_LINE_SIZE
bhi 1b
ret lr
/*
* cpu_v6_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_v6_switch_mm)
#ifdef CONFIG_MMU
mov r2, #0
mmid r1, r1 @ get mm->context.id
ALT_SMP(orr r0, r0, #TTB_FLAGS_SMP)
ALT_UP(orr r0, r0, #TTB_FLAGS_UP)
mcr p15, 0, r2, c7, c5, 6 @ flush BTAC/BTB
mcr p15, 0, r2, c7, c10, 4 @ drain write buffer
mcr p15, 0, r0, c2, c0, 0 @ set TTB 0
#ifdef CONFIG_PID_IN_CONTEXTIDR
mrc p15, 0, r2, c13, c0, 1 @ read current context ID
bic r2, r2, #0xff @ extract the PID
and r1, r1, #0xff
orr r1, r1, r2 @ insert into new context ID
#endif
mcr p15, 0, r1, c13, c0, 1 @ set context ID
#endif
ret lr
/*
* cpu_v6_set_pte_ext(ptep, pte, ext)
*
* 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
*/
armv6_mt_table cpu_v6
ENTRY(cpu_v6_set_pte_ext)
#ifdef CONFIG_MMU
armv6_set_pte_ext cpu_v6
#endif
ret lr
/* Suspend/resume support: taken from arch/arm/mach-s3c64xx/sleep.S */
.globl cpu_v6_suspend_size
.equ cpu_v6_suspend_size, 4 * 6
#ifdef CONFIG_ARM_CPU_SUSPEND
ENTRY(cpu_v6_do_suspend)
stmfd sp!, {r4 - r9, lr}
mrc p15, 0, r4, c13, c0, 0 @ FCSE/PID
#ifdef CONFIG_MMU
mrc p15, 0, r5, c3, c0, 0 @ Domain ID
mrc p15, 0, r6, c2, c0, 1 @ Translation table base 1
#endif
mrc p15, 0, r7, c1, c0, 1 @ auxiliary control register
mrc p15, 0, r8, c1, c0, 2 @ co-processor access control
mrc p15, 0, r9, c1, c0, 0 @ control register
stmia r0, {r4 - r9}
ldmfd sp!, {r4- r9, pc}
ENDPROC(cpu_v6_do_suspend)
ENTRY(cpu_v6_do_resume)
mov ip, #0
mcr p15, 0, ip, c7, c14, 0 @ clean+invalidate D cache
mcr p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcr p15, 0, ip, c7, c15, 0 @ clean+invalidate cache
mcr p15, 0, ip, c7, c10, 4 @ drain write buffer
mcr p15, 0, ip, c13, c0, 1 @ set reserved context ID
ldmia r0, {r4 - r9}
mcr p15, 0, r4, c13, c0, 0 @ FCSE/PID
#ifdef CONFIG_MMU
mcr p15, 0, r5, 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 @ Translation table base 0
mcr p15, 0, r6, c2, c0, 1 @ Translation table base 1
mcr p15, 0, ip, c2, c0, 2 @ TTB control register
#endif
mcr p15, 0, r7, c1, c0, 1 @ auxiliary control register
mcr p15, 0, r8, c1, c0, 2 @ co-processor access control
mcr p15, 0, ip, c7, c5, 4 @ ISB
mov r0, r9 @ control register
b cpu_resume_mmu
ENDPROC(cpu_v6_do_resume)
#endif
string cpu_v6_name, "ARMv6-compatible processor"
.align
/*
* __v6_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 ARMv6 cores.
*
* It is assumed that:
* - cache type register is implemented
*/
__v6_setup:
#ifdef CONFIG_SMP
ALT_SMP(mrc p15, 0, r0, c1, c0, 1) @ Enable SMP/nAMP mode
ALT_UP(nop)
orr r0, r0, #0x20
ALT_SMP(mcr p15, 0, r0, c1, c0, 1)
ALT_UP(nop)
#endif
mov r0, #0
mcr p15, 0, r0, c7, c14, 0 @ clean+invalidate D cache
mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
mcr p15, 0, r0, c7, c15, 0 @ clean+invalidate cache
#ifdef CONFIG_MMU
mcr p15, 0, r0, c8, c7, 0 @ invalidate I + D TLBs
mcr p15, 0, r0, 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
#endif /* CONFIG_MMU */
mcr p15, 0, r0, c7, c10, 4 @ drain write buffer and
@ complete invalidations
adr r5, v6_crval
ldmia r5, {r5, r6}
ARM_BE8(orr r6, r6, #1 << 25) @ big-endian page tables
mrc p15, 0, r0, c1, c0, 0 @ read control register
bic r0, r0, r5 @ clear bits them
orr r0, r0, r6 @ set them
#ifdef CONFIG_ARM_ERRATA_364296
/*
* Workaround for the 364296 ARM1136 r0p2 erratum (possible cache data
* corruption with hit-under-miss enabled). The conditional code below
* (setting the undocumented bit 31 in the auxiliary control register
* and the FI bit in the control register) disables hit-under-miss
* without putting the processor into full low interrupt latency mode.
*/
ldr r6, =0x4107b362 @ id for ARM1136 r0p2
mrc p15, 0, r5, c0, c0, 0 @ get processor id
teq r5, r6 @ check for the faulty core
mrceq p15, 0, r5, c1, c0, 1 @ load aux control reg
orreq r5, r5, #(1 << 31) @ set the undocumented bit 31
mcreq p15, 0, r5, c1, c0, 1 @ write aux control reg
orreq r0, r0, #(1 << 21) @ low interrupt latency configuration
#endif
ret lr @ return to head.S:__ret
/*
* V X F I D LR
* .... ...E PUI. .T.T 4RVI ZFRS BLDP WCAM
* rrrr rrrx xxx0 0101 xxxx xxxx x111 xxxx < forced
* 0 110 0011 1.00 .111 1101 < we want
*/
.type v6_crval, #object
v6_crval:
crval clear=0x01e0fb7f, mmuset=0x00c0387d, ucset=0x00c0187c
__INITDATA
@ define struct processor (see <asm/proc-fns.h> and proc-macros.S)
define_processor_functions v6, dabort=v6_early_abort, pabort=v6_pabort, suspend=1
.section ".rodata"
string cpu_arch_name, "armv6"
string cpu_elf_name, "v6"
.align
.section ".proc.info.init", "a"
/*
* Match any ARMv6 processor core.
*/
.type __v6_proc_info, #object
__v6_proc_info:
.long 0x0007b000
.long 0x0007f000
ALT_SMP(.long \
PMD_TYPE_SECT | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ | \
PMD_FLAGS_SMP)
ALT_UP(.long \
PMD_TYPE_SECT | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ | \
PMD_FLAGS_UP)
.long PMD_TYPE_SECT | \
PMD_SECT_XN | \
PMD_SECT_AP_WRITE | \
PMD_SECT_AP_READ
initfn __v6_setup, __v6_proc_info
.long cpu_arch_name
.long cpu_elf_name
/* See also feat_v6_fixup() for HWCAP_TLS */
.long HWCAP_SWP|HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT|HWCAP_EDSP|HWCAP_JAVA|HWCAP_TLS
.long cpu_v6_name
.long v6_processor_functions
.long v6wbi_tlb_fns
.long v6_user_fns
.long v6_cache_fns
.size __v6_proc_info, . - __v6_proc_info