239 lines
		
	
	
		
			6.1 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			239 lines
		
	
	
		
			6.1 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| /*
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|  *  linux/arch/arm/mm/proc-v7m.S
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|  *
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|  *  Copyright (C) 2008 ARM Ltd.
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|  *  Copyright (C) 2001 Deep Blue Solutions Ltd.
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|  *
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|  * This program is free software; you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License version 2 as
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|  * published by the Free Software Foundation.
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|  *
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|  *  This is the "shell" of the ARMv7-M processor support.
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|  */
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| #include <linux/linkage.h>
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| #include <asm/assembler.h>
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| #include <asm/memory.h>
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| #include <asm/v7m.h>
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| #include "proc-macros.S"
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| 
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| ENTRY(cpu_v7m_proc_init)
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| 	ret	lr
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| ENDPROC(cpu_v7m_proc_init)
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| 
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| ENTRY(cpu_v7m_proc_fin)
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| 	ret	lr
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| ENDPROC(cpu_v7m_proc_fin)
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| 
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| /*
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|  *	cpu_v7m_reset(loc)
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|  *
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|  *	Perform a soft reset of the system.  Put the CPU into the
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|  *	same state as it would be if it had been reset, and branch
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|  *	to what would be the reset vector.
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|  *
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|  *	- loc   - location to jump to for soft reset
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|  */
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| 	.align	5
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| ENTRY(cpu_v7m_reset)
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| 	ret	r0
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| ENDPROC(cpu_v7m_reset)
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| 
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| /*
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|  *	cpu_v7m_do_idle()
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|  *
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|  *	Idle the processor (eg, wait for interrupt).
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|  *
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|  *	IRQs are already disabled.
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|  */
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| ENTRY(cpu_v7m_do_idle)
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| 	wfi
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| 	ret	lr
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| ENDPROC(cpu_v7m_do_idle)
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| 
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| ENTRY(cpu_v7m_dcache_clean_area)
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| 	ret	lr
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| ENDPROC(cpu_v7m_dcache_clean_area)
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| 
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| /*
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|  * There is no MMU, so here is nothing to do.
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|  */
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| ENTRY(cpu_v7m_switch_mm)
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| 	ret	lr
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| ENDPROC(cpu_v7m_switch_mm)
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| 
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| .globl	cpu_v7m_suspend_size
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| .equ	cpu_v7m_suspend_size, 0
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| 
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| #ifdef CONFIG_ARM_CPU_SUSPEND
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| ENTRY(cpu_v7m_do_suspend)
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| 	ret	lr
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| ENDPROC(cpu_v7m_do_suspend)
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| 
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| ENTRY(cpu_v7m_do_resume)
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| 	ret	lr
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| ENDPROC(cpu_v7m_do_resume)
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| #endif
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| 
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| ENTRY(cpu_cm7_dcache_clean_area)
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| 	dcache_line_size r2, r3
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| 	movw	r3, #:lower16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
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| 	movt	r3, #:upper16:BASEADDR_V7M_SCB + V7M_SCB_DCCMVAC
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| 
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| 1:	str	r0, [r3]		@ clean D entry
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| 	add	r0, r0, r2
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| 	subs	r1, r1, r2
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| 	bhi	1b
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| 	dsb
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| 	ret	lr
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| ENDPROC(cpu_cm7_dcache_clean_area)
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| 
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| ENTRY(cpu_cm7_proc_fin)
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| 	movw	r2, #:lower16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
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| 	movt	r2, #:upper16:(BASEADDR_V7M_SCB + V7M_SCB_CCR)
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| 	ldr	r0, [r2]
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| 	bic	r0, r0, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC)
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| 	str	r0, [r2]
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| 	ret	lr
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| ENDPROC(cpu_cm7_proc_fin)
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| 
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| 	.section ".init.text", #alloc, #execinstr
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| 
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| __v7m_cm7_setup:
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| 	mov	r8, #(V7M_SCB_CCR_DC | V7M_SCB_CCR_IC| V7M_SCB_CCR_BP)
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| 	b	__v7m_setup_cont
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| /*
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|  *	__v7m_setup
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|  *
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|  *	This should be able to cover all ARMv7-M cores.
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|  */
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| __v7m_setup:
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| 	mov	r8, 0
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| 
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| __v7m_setup_cont:
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| 	@ Configure the vector table base address
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| 	ldr	r0, =BASEADDR_V7M_SCB
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| 	ldr	r12, =vector_table
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| 	str	r12, [r0, V7M_SCB_VTOR]
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| 
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| 	@ enable UsageFault, BusFault and MemManage fault.
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| 	ldr	r5, [r0, #V7M_SCB_SHCSR]
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| 	orr	r5, #(V7M_SCB_SHCSR_USGFAULTENA | V7M_SCB_SHCSR_BUSFAULTENA | V7M_SCB_SHCSR_MEMFAULTENA)
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| 	str	r5, [r0, #V7M_SCB_SHCSR]
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| 
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| 	@ Lower the priority of the SVC and PendSV exceptions
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| 	mov	r5, #0x80000000
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| 	str	r5, [r0, V7M_SCB_SHPR2]	@ set SVC priority
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| 	mov	r5, #0x00800000
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| 	str	r5, [r0, V7M_SCB_SHPR3]	@ set PendSV priority
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| 
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| 	@ SVC to switch to handler mode. Notice that this requires sp to
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| 	@ point to writeable memory because the processor saves
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| 	@ some registers to the stack.
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| 	badr	r1, 1f
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| 	ldr	r5, [r12, #11 * 4]	@ read the SVC vector entry
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| 	str	r1, [r12, #11 * 4]	@ write the temporary SVC vector entry
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| 	dsb
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| 	mov	r6, lr			@ save LR
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| 	ldr	sp, =init_thread_union + THREAD_START_SP
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| 	cpsie	i
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| 	svc	#0
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| 1:	cpsid	i
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| 	/* Calculate exc_ret */
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| 	orr	r10, lr, #EXC_RET_THREADMODE_PROCESSSTACK
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| 	ldmia	sp, {r0-r3, r12}
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| 	str	r5, [r12, #11 * 4]	@ restore the original SVC vector entry
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| 	mov	lr, r6			@ restore LR
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| 
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| 	@ Special-purpose control register
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| 	mov	r1, #1
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| 	msr	control, r1		@ Thread mode has unpriviledged access
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| 
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| 	@ Configure caches (if implemented)
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| 	teq     r8, #0
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| 	stmneia	sp, {r0-r6, lr}		@ v7m_invalidate_l1 touches r0-r6
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| 	blne	v7m_invalidate_l1
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| 	teq     r8, #0			@ re-evalutae condition
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| 	ldmneia	sp, {r0-r6, lr}
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| 
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| 	@ Configure the System Control Register to ensure 8-byte stack alignment
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| 	@ Note the STKALIGN bit is either RW or RAO.
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| 	ldr	r0, [r0, V7M_SCB_CCR]   @ system control register
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| 	orr	r0, #V7M_SCB_CCR_STKALIGN
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| 	orr	r0, r0, r8
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| 
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| 	ret	lr
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| ENDPROC(__v7m_setup)
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| 
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| /*
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|  * Cortex-M7 processor functions
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|  */
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| 	globl_equ	cpu_cm7_proc_init,	cpu_v7m_proc_init
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| 	globl_equ	cpu_cm7_reset,		cpu_v7m_reset
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| 	globl_equ	cpu_cm7_do_idle,	cpu_v7m_do_idle
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| 	globl_equ	cpu_cm7_switch_mm,	cpu_v7m_switch_mm
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| 
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| 	define_processor_functions v7m, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
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| 	define_processor_functions cm7, dabort=nommu_early_abort, pabort=legacy_pabort, nommu=1
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| 
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| 	.section ".rodata"
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| 	string cpu_arch_name, "armv7m"
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| 	string cpu_elf_name "v7m"
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| 	string cpu_v7m_name "ARMv7-M"
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| 
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| 	.section ".proc.info.init", #alloc
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| 
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| .macro __v7m_proc name, initfunc, cache_fns = nop_cache_fns, hwcaps = 0,  proc_fns = v7m_processor_functions
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| 	.long	0			/* proc_info_list.__cpu_mm_mmu_flags */
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| 	.long	0			/* proc_info_list.__cpu_io_mmu_flags */
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| 	initfn	\initfunc, \name
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| 	.long	cpu_arch_name
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| 	.long	cpu_elf_name
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| 	.long	HWCAP_HALF | HWCAP_THUMB | HWCAP_FAST_MULT | \hwcaps
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| 	.long	cpu_v7m_name
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| 	.long   \proc_fns
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| 	.long	0			/* proc_info_list.tlb */
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| 	.long	0			/* proc_info_list.user */
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| 	.long	\cache_fns
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| .endm
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| 
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| 	/*
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| 	 * Match ARM Cortex-M7 processor.
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| 	 */
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| 	.type	__v7m_cm7_proc_info, #object
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| __v7m_cm7_proc_info:
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| 	.long	0x410fc270		/* ARM Cortex-M7 0xC27 */
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| 	.long	0xff0ffff0		/* Mask off revision, patch release */
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| 	__v7m_proc __v7m_cm7_proc_info, __v7m_cm7_setup, hwcaps = HWCAP_EDSP, cache_fns = v7m_cache_fns, proc_fns = cm7_processor_functions
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| 	.size	__v7m_cm7_proc_info, . - __v7m_cm7_proc_info
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| 
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| 	/*
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| 	 * Match ARM Cortex-M4 processor.
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| 	 */
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| 	.type	__v7m_cm4_proc_info, #object
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| __v7m_cm4_proc_info:
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| 	.long	0x410fc240		/* ARM Cortex-M4 0xC24 */
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| 	.long	0xff0ffff0		/* Mask off revision, patch release */
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| 	__v7m_proc __v7m_cm4_proc_info, __v7m_setup, hwcaps = HWCAP_EDSP
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| 	.size	__v7m_cm4_proc_info, . - __v7m_cm4_proc_info
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| 
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| 	/*
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| 	 * Match ARM Cortex-M3 processor.
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| 	 */
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| 	.type	__v7m_cm3_proc_info, #object
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| __v7m_cm3_proc_info:
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| 	.long	0x410fc230		/* ARM Cortex-M3 0xC23 */
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| 	.long	0xff0ffff0		/* Mask off revision, patch release */
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| 	__v7m_proc __v7m_cm3_proc_info, __v7m_setup
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| 	.size	__v7m_cm3_proc_info, . - __v7m_cm3_proc_info
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| 
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| 	/*
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| 	 * Match any ARMv7-M processor core.
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| 	 */
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| 	.type	__v7m_proc_info, #object
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| __v7m_proc_info:
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| 	.long	0x000f0000		@ Required ID value
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| 	.long	0x000f0000		@ Mask for ID
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| 	__v7m_proc __v7m_proc_info, __v7m_setup
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| 	.size	__v7m_proc_info, . - __v7m_proc_info
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| 
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