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Diffstat (limited to 'arch/arm/mm/proc-v7m.S')
| -rw-r--r-- | arch/arm/mm/proc-v7m.S | 238 |
1 files changed, 238 insertions, 0 deletions
diff --git a/arch/arm/mm/proc-v7m.S b/arch/arm/mm/proc-v7m.S new file mode 100644 index 000000000..9c2978c12 --- /dev/null +++ b/arch/arm/mm/proc-v7m.S @@ -0,0 +1,238 @@ +/* + * 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 + cpsie i + svc #0 +1: cpsid i + /* Calculate exc_ret */ + orr r10, lr, #EXC_RET_THREADMODE_PROCESSSTACK + 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 + stmneia sp, {r0-r6, lr} @ v7m_invalidate_l1 touches r0-r6 + blne v7m_invalidate_l1 + teq r8, #0 @ re-evalutae condition + ldmneia 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 + |