diff options
Diffstat (limited to 'arch/arm/mm/proc-v7m.S')
| -rw-r--r-- | arch/arm/mm/proc-v7m.S | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/arch/arm/mm/proc-v7m.S b/arch/arm/mm/proc-v7m.S new file mode 100644 index 000000000000..0c93588fcb91 --- /dev/null +++ b/arch/arm/mm/proc-v7m.S @@ -0,0 +1,157 @@ +/* + * 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/v7m.h> +#include "proc-macros.S" + +ENTRY(cpu_v7m_proc_init) + mov pc, lr +ENDPROC(cpu_v7m_proc_init) + +ENTRY(cpu_v7m_proc_fin) + mov pc, 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) + mov pc, 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 + mov pc, lr +ENDPROC(cpu_v7m_do_idle) + +ENTRY(cpu_v7m_dcache_clean_area) + mov pc, lr +ENDPROC(cpu_v7m_dcache_clean_area) + +/* + * There is no MMU, so here is nothing to do. + */ +ENTRY(cpu_v7m_switch_mm) + mov pc, 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) + mov pc, lr +ENDPROC(cpu_v7m_do_suspend) + +ENTRY(cpu_v7m_do_resume) + mov pc, lr +ENDPROC(cpu_v7m_do_resume) +#endif + + .section ".text.init", #alloc, #execinstr + +/* + * __v7m_setup + * + * This should be able to cover all ARMv7-M cores. + */ +__v7m_setup: + @ 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 run the kernel in this mode + adr r1, BSYM(1f) + ldr r5, [r12, #11 * 4] @ read the SVC vector entry + str r1, [r12, #11 * 4] @ write the temporary SVC vector entry + mov r6, lr @ save LR + mov r7, sp @ save SP + ldr sp, =__v7m_setup_stack_top + cpsie i + svc #0 +1: cpsid i + str r5, [r12, #11 * 4] @ restore the original SVC vector entry + mov lr, r6 @ restore LR + mov sp, r7 @ restore SP + + @ Special-purpose control register + mov r1, #1 + msr control, r1 @ Thread mode has unpriviledged access + + @ Configure the System Control Register to ensure 8-byte stack alignment + @ Note the STKALIGN bit is either RW or RAO. + ldr r12, [r0, V7M_SCB_CCR] @ system control register + orr r12, #V7M_SCB_CCR_STKALIGN + str r12, [r0, V7M_SCB_CCR] + mov pc, lr +ENDPROC(__v7m_setup) + + define_processor_functions v7m, 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, #execinstr + + /* + * Match any ARMv7-M processor core. + */ + .type __v7m_proc_info, #object +__v7m_proc_info: + .long 0x000f0000 @ Required ID value + .long 0x000f0000 @ Mask for ID + .long 0 @ proc_info_list.__cpu_mm_mmu_flags + .long 0 @ proc_info_list.__cpu_io_mmu_flags + b __v7m_setup @ proc_info_list.__cpu_flush + .long cpu_arch_name + .long cpu_elf_name + .long HWCAP_HALF|HWCAP_THUMB|HWCAP_FAST_MULT + .long cpu_v7m_name + .long v7m_processor_functions @ proc_info_list.proc + .long 0 @ proc_info_list.tlb + .long 0 @ proc_info_list.user + .long nop_cache_fns @ proc_info_list.cache + .size __v7m_proc_info, . - __v7m_proc_info + +__v7m_setup_stack: + .space 4 * 8 @ 8 registers +__v7m_setup_stack_top: |