/*
* linux/arch/arm/mm/proc-v7m.S
*
* Copyright (C) 2008 ARM Ltd.
* 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-M processor support.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/memory.h>
#include <asm/v7m.h>
#include "proc-macros.S"
ENTRY(cpu_v7m_proc_init)
ret lr
ENDPROC(cpu_v7m_proc_init)
ENTRY(cpu_v7m_proc_fin)
ret lr
ENDPROC(cpu_v7m_proc_fin)
/*
* cpu_v7m_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
ENTRY(cpu_v7m_reset)
ret r0
ENDPROC(cpu_v7m_reset)
/*
* cpu_v7m_do_idle()
*
* Idle the processor (eg, wait for interrupt).
*
* IRQs are already disabled.
*/
ENTRY(cpu_v7m_do_idle)
wfi
ret lr
ENDPROC(cpu_v7m_do_idle)
ENTRY(cpu_v7m_dcache_clean_area)
ret lr
ENDPROC(cpu_v7m_dcache_clean_area)
/*
* There is no MMU, so here is nothing to do.
*/
ENTRY(cpu_v7m_switch_mm)
ret lr
ENDPROC(cpu_v7m_switch_mm)
.globl cpu_v7m_suspend_size
.equ cpu_v7m_suspend_size, 0
#ifdef CONFIG_ARM_CPU_SUSPEND
ENTRY(cpu_v7m_do_suspend)
ret lr
ENDPROC(cpu_v7m_do_suspend)
ENTRY(cpu_v7m_do_resume)
ret lr
ENDPROC(cpu_v7m_do_resume)
#endif
ENTRY(cpu_cm7_dcache_clean_area)
dcache_line_size r2, r3
movw r3, #:lower16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
movt r3, #:upper16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
1: str r0, [r3] @ clean D entry
add r0, r0, r2
subs r1, r1, r2
bhi 1b
dsb
ret lr
ENDPROC(cpu_cm7_dcache_clean_area)
ENTRY(cpu_cm7_proc_fin)
movw r2, #:lower16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
movt r2, #:upper16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
ldr r0, [r2]
bic r0, r0, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC)
str r0, [r2]
ret lr
ENDPROC(cpu_cm7_proc_fin)
.section ".init.text", #alloc, #execinstr
__v7m_cm7_setup:
mov r8, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC| V7M_SCB_CCR_BP)
b __v7m_setup_cont
/*
* __v7m_setup
*
* This should be able to cover all ARMv7-M cores.
*/
__v7m_setup:
mov r8, 0
__v7m_setup_cont:
@ Configure the vector table base address
ldr r0, =BASEADDR_V7M_SCB
ldr r12, =vector_table
str r12, [r0, V7M_SCB_VTOR]
@ enable UsageFault, BusFault and MemManage fault.
ldr r5, [r0, #V7M_SCB_SHCSR]
orr r5, #(V7M_SCB_SHCSR_USGFAULTENA | V7M_SCB_SHCSR_BUSFAULTENA | V7M_SCB_SHCSR_MEMFAULTENA)
str r5, [r0, #V7M_SCB_SHCSR]
@ Lower the priority of the SVC and PendSV exceptions
mov r5, #0x80000000
str r5, [r0, V7M_SCB_SHPR2] @ set SVC priority
mov r5, #0x00800000
str r5, [r0, V7M_SCB_SHPR3] @ set PendSV priority
@ SVC to switch to handler mode. Notice that this requires sp to
@ point to writeable memory because the processor saves
@ some registers to the stack.
badr r1, 1f
ldr r5, [r12, #11 * 4] @ read the SVC vector entry
str r1, [r12, #11 * 4] @ write the temporary SVC vector entry
dsb
mov r6, lr @ save LR
ldr sp, =init_thread_union + THREAD_START_SP
stmia sp, {r0-r3, r12}
cpsie i
svc #0
1: cpsid i
ldr r0, =exc_ret
orr lr, lr, #EXC_RET_THREADMODE_PROCESSSTACK
str lr, [r0]
ldmia sp, {r0-r3, r12}
str r5, [r12, #11 * 4] @ restore the original SVC vector entry
mov lr, r6 @ restore LR
@ Special-purpose control register
mov r1, #1
msr control, r1 @ Thread mode has unpriviledged access
@ Configure caches (if implemented)
teq r8, #0
stmiane sp, {r0-r6, lr} @ v7m_invalidate_l1 touches r0-r6
blne v7m_invalidate_l1
teq r8, #0 @ re-evalutae condition
ldmiane sp, {r0-r6, lr}
@ Configure the System Control Register to ensure 8-byte stack alignment
@ Note the STKALIGN bit is either RW or RAO.
ldr r0, [r0, V7M_SCB_CCR] @ system control register
orr r0, #V7M_SCB_CCR_STKALIGN
orr r0, r0, r8
ret lr
ENDPROC(__v7m_setup)
/*
* Cortex-M7 processor functions
*/
globl_equ cpu_cm7_proc_init, cpu_v7m_proc_init
globl_equ cpu_cm7_reset, cpu_v7m_reset
globl_equ cpu_cm7_do_idle, cpu_v7m_do_idle
globl_equ cpu_cm7_switch_mm, cpu_v7m_switch_mm
define_processor_functions v7m, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
define_processor_functions cm7, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
.section ".rodata"
string cpu_arch_name, "armv7m"
string cpu_elf_name "v7m"
string cpu_v7m_name "ARMv7-M"
.section ".proc.info.init", #alloc
.macro __v7m_proc name, initfunc, cache_fns = nop_cache_fns, hwcaps = 0, proc_fns = v7m_processor_functions
.long 0 /* proc_info_list.__cpu_mm_mmu_flags */
.long 0 /* proc_info_list.__cpu_io_mmu_flags */
initfn \initfunc, \name
.long cpu_arch_name
.long cpu_elf_name
.long HWCAP_HALF | HWCAP_THUMB | HWCAP_FAST_MULT | \hwcaps
.long cpu_v7m_name
.long \proc_fns
.long 0 /* proc_info_list.tlb */
.long 0 /* proc_info_list.user */
.long \cache_fns
.endm
/*
* Match ARM Cortex-M7 processor.
*/
.type __v7m_cm7_proc_info, #object
__v7m_cm7_proc_info:
.long 0x410fc270 /* ARM Cortex-M7 0xC27 */
.long 0xff0ffff0 /* Mask off revision, patch release */
__v7m_proc __v7m_cm7_proc_info, __v7m_cm7_setup, hwcaps = HWCAP_EDSP, cache_fns = v7m_cache_fns, proc_fns = cm7_processor_functions
.size __v7m_cm7_proc_info, . - __v7m_cm7_proc_info
/*
* Match ARM Cortex-M4 processor.
*/
.type __v7m_cm4_proc_info, #object
__v7m_cm4_proc_info:
.long 0x410fc240 /* ARM Cortex-M4 0xC24 */
.long 0xff0ffff0 /* Mask off revision, patch release */
__v7m_proc __v7m_cm4_proc_info, __v7m_setup, hwcaps = HWCAP_EDSP
.size __v7m_cm4_proc_info, . - __v7m_cm4_proc_info
/*
* Match ARM Cortex-M3 processor.
*/
.type __v7m_cm3_proc_info, #object
__v7m_cm3_proc_info:
.long 0x410fc230 /* ARM Cortex-M3 0xC23 */
.long 0xff0ffff0 /* Mask off revision, patch release */
__v7m_proc __v7m_cm3_proc_info, __v7m_setup
.size __v7m_cm3_proc_info, . - __v7m_cm3_proc_info
/*
* Match any ARMv7-M processor core.
*/
.type __v7m_proc_info, #object
__v7m_proc_info:
.long 0x000f0000 @ Required ID value
.long 0x000f0000 @ Mask for ID
__v7m_proc __v7m_proc_info, __v7m_setup
.size __v7m_proc_info, . - __v7m_proc_info
