arch/arm/mm/cache-v7.S - maze/linux - Git at Google

 /*
  *  linux/arch/arm/mm/cache-v7.S
  *
  *  Copyright (C) 2001 Deep Blue Solutions Ltd.
  *  Copyright (C) 2005 ARM 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 processor support.
  */
 #include <linux/linkage.h>
 #include <linux/init.h>
 #include <asm/assembler.h>
 #include <asm/unwind.h>

 #include "proc-macros.S"

 /*
  *	v7_flush_icache_all()
  *
  *	Flush the whole I-cache.
  *
  *	Registers:
  *	r0 - set to 0
  */
 ENTRY(v7_flush_icache_all)
 	mov	r0, #0
 	ALT_SMP(mcr	p15, 0, r0, c7, c1, 0)		@ invalidate I-cache inner shareable
 	ALT_UP(mcr	p15, 0, r0, c7, c5, 0)		@ I+BTB cache invalidate
 	mov	pc, lr
 ENDPROC(v7_flush_icache_all)

 /*
  *	v7_flush_dcache_all()
  *
  *	Flush the whole D-cache.
  *
  *	Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
  *
  *	- mm    - mm_struct describing address space
  */
 ENTRY(v7_flush_dcache_all)
 	dmb					@ ensure ordering with previous memory accesses
 	mrc	p15, 1, r0, c0, c0, 1		@ read clidr
 	ands	r3, r0, #0x7000000		@ extract loc from clidr
 	mov	r3, r3, lsr #23			@ left align loc bit field
 	beq	finished			@ if loc is 0, then no need to clean
 	mov	r10, #0				@ start clean at cache level 0
 loop1:
 	add	r2, r10, r10, lsr #1		@ work out 3x current cache level
 	mov	r1, r0, lsr r2			@ extract cache type bits from clidr
 	and	r1, r1, #7			@ mask of the bits for current cache only
 	cmp	r1, #2				@ see what cache we have at this level
 	blt	skip				@ skip if no cache, or just i-cache
 	mcr	p15, 2, r10, c0, c0, 0		@ select current cache level in cssr
 	isb					@ isb to sych the new cssr&csidr
 	mrc	p15, 1, r1, c0, c0, 0		@ read the new csidr
 	and	r2, r1, #7			@ extract the length of the cache lines
 	add	r2, r2, #4			@ add 4 (line length offset)
 	ldr	r4, =0x3ff
 	ands	r4, r4, r1, lsr #3		@ find maximum number on the way size
 	clz	r5, r4				@ find bit position of way size increment
 	ldr	r7, =0x7fff
 	ands	r7, r7, r1, lsr #13		@ extract max number of the index size
 loop2:
 	mov	r9, r4				@ create working copy of max way size
 loop3:
  ARM(	orr	r11, r10, r9, lsl r5	)	@ factor way and cache number into r11
  THUMB(	lsl	r6, r9, r5		)
  THUMB(	orr	r11, r10, r6		)	@ factor way and cache number into r11
  ARM(	orr	r11, r11, r7, lsl r2	)	@ factor index number into r11
  THUMB(	lsl	r6, r7, r2		)
  THUMB(	orr	r11, r11, r6		)	@ factor index number into r11
 	mcr	p15, 0, r11, c7, c14, 2		@ clean & invalidate by set/way
 	subs	r9, r9, #1			@ decrement the way
 	bge	loop3
 	subs	r7, r7, #1			@ decrement the index
 	bge	loop2
 skip:
 	add	r10, r10, #2			@ increment cache number
 	cmp	r3, r10
 	bgt	loop1
 finished:
 	mov	r10, #0				@ swith back to cache level 0
 	mcr	p15, 2, r10, c0, c0, 0		@ select current cache level in cssr
 	dsb
 	isb
 	mov	pc, lr
 ENDPROC(v7_flush_dcache_all)

 /*
  *	v7_flush_cache_all()
  *
  *	Flush the entire cache system.
  *  The data cache flush is now achieved using atomic clean / invalidates
  *  working outwards from L1 cache. This is done using Set/Way based cache
  *  maintainance instructions.
  *  The instruction cache can still be invalidated back to the point of
  *  unification in a single instruction.
  *
  */
 ENTRY(v7_flush_kern_cache_all)
  ARM(	stmfd	sp!, {r4-r5, r7, r9-r11, lr}	)
  THUMB(	stmfd	sp!, {r4-r7, r9-r11, lr}	)
 	bl	v7_flush_dcache_all
 	mov	r0, #0
 	ALT_SMP(mcr	p15, 0, r0, c7, c1, 0)	@ invalidate I-cache inner shareable
 	ALT_UP(mcr	p15, 0, r0, c7, c5, 0)	@ I+BTB cache invalidate
  ARM(	ldmfd	sp!, {r4-r5, r7, r9-r11, lr}	)
  THUMB(	ldmfd	sp!, {r4-r7, r9-r11, lr}	)
 	mov	pc, lr
 ENDPROC(v7_flush_kern_cache_all)

 /*
  *	v7_flush_cache_all()
  *
  *	Flush all TLB entries in a particular address space
  *
  *	- mm    - mm_struct describing address space
  */
 ENTRY(v7_flush_user_cache_all)
 	/*FALLTHROUGH*/

 /*
  *	v7_flush_cache_range(start, end, flags)
  *
  *	Flush a range of TLB entries in the specified address space.
  *
  *	- start - start address (may not be aligned)
  *	- end   - end address (exclusive, may not be aligned)
  *	- flags	- vm_area_struct flags describing address space
  *
  *	It is assumed that:
  *	- we have a VIPT cache.
  */
 ENTRY(v7_flush_user_cache_range)
 	mov	pc, lr
 ENDPROC(v7_flush_user_cache_all)
 ENDPROC(v7_flush_user_cache_range)

 /*
  *	v7_coherent_kern_range(start,end)
  *
  *	Ensure that the I and D caches are coherent within specified
  *	region.  This is typically used when code has been written to
  *	a memory region, and will be executed.
  *
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  *
  *	It is assumed that:
  *	- the Icache does not read data from the write buffer
  */
 ENTRY(v7_coherent_kern_range)
 	/* FALLTHROUGH */

 /*
  *	v7_coherent_user_range(start,end)
  *
  *	Ensure that the I and D caches are coherent within specified
  *	region.  This is typically used when code has been written to
  *	a memory region, and will be executed.
  *
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  *
  *	It is assumed that:
  *	- the Icache does not read data from the write buffer
  */
 ENTRY(v7_coherent_user_range)
  UNWIND(.fnstart		)
 	dcache_line_size r2, r3
 	sub	r3, r2, #1
 	bic	r12, r0, r3
 1:
  USER(	mcr	p15, 0, r12, c7, c11, 1	)	@ clean D line to the point of unification
 	add	r12, r12, r2
 	cmp	r12, r1
 	blo	1b
 	dsb
 	icache_line_size r2, r3
 	sub	r3, r2, #1
 	bic	r12, r0, r3
 2:
  USER(	mcr	p15, 0, r12, c7, c5, 1	)	@ invalidate I line
 	add	r12, r12, r2
 	cmp	r12, r1
 	blo	2b
 3:
 	mov	r0, #0
 	ALT_SMP(mcr	p15, 0, r0, c7, c1, 6)	@ invalidate BTB Inner Shareable
 	ALT_UP(mcr	p15, 0, r0, c7, c5, 6)	@ invalidate BTB
 	dsb
 	isb
 	mov	pc, lr

 /*
  * Fault handling for the cache operation above. If the virtual address in r0
  * isn't mapped, just try the next page.
  */
 9001:
 	mov	r12, r12, lsr #12
 	mov	r12, r12, lsl #12
 	add	r12, r12, #4096
 	b	3b
  UNWIND(.fnend		)
 ENDPROC(v7_coherent_kern_range)
 ENDPROC(v7_coherent_user_range)

 /*
  *	v7_flush_kern_dcache_area(void *addr, size_t size)
  *
  *	Ensure that the data held in the page kaddr is written back
  *	to the page in question.
  *
  *	- addr	- kernel address
  *	- size	- region size
  */
 ENTRY(v7_flush_kern_dcache_area)
 	dcache_line_size r2, r3
 	add	r1, r0, r1
 1:
 	mcr	p15, 0, r0, c7, c14, 1		@ clean & invalidate D line / unified line
 	add	r0, r0, r2
 	cmp	r0, r1
 	blo	1b
 	dsb
 	mov	pc, lr
 ENDPROC(v7_flush_kern_dcache_area)

 /*
  *	v7_dma_inv_range(start,end)
  *
  *	Invalidate the data cache within the specified region; we will
  *	be performing a DMA operation in this region and we want to
  *	purge old data in the cache.
  *
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  */
 v7_dma_inv_range:
 	dcache_line_size r2, r3
 	sub	r3, r2, #1
 	tst	r0, r3
 	bic	r0, r0, r3
 	mcrne	p15, 0, r0, c7, c14, 1		@ clean & invalidate D / U line

 	tst	r1, r3
 	bic	r1, r1, r3
 	mcrne	p15, 0, r1, c7, c14, 1		@ clean & invalidate D / U line
 1:
 	mcr	p15, 0, r0, c7, c6, 1		@ invalidate D / U line
 	add	r0, r0, r2
 	cmp	r0, r1
 	blo	1b
 	dsb
 	mov	pc, lr
 ENDPROC(v7_dma_inv_range)

 /*
  *	v7_dma_clean_range(start,end)
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  */
 v7_dma_clean_range:
 	dcache_line_size r2, r3
 	sub	r3, r2, #1
 	bic	r0, r0, r3
 1:
 	mcr	p15, 0, r0, c7, c10, 1		@ clean D / U line
 	add	r0, r0, r2
 	cmp	r0, r1
 	blo	1b
 	dsb
 	mov	pc, lr
 ENDPROC(v7_dma_clean_range)

 /*
  *	v7_dma_flush_range(start,end)
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  */
 ENTRY(v7_dma_flush_range)
 	dcache_line_size r2, r3
 	sub	r3, r2, #1
 	bic	r0, r0, r3
 1:
 	mcr	p15, 0, r0, c7, c14, 1		@ clean & invalidate D / U line
 	add	r0, r0, r2
 	cmp	r0, r1
 	blo	1b
 	dsb
 	mov	pc, lr
 ENDPROC(v7_dma_flush_range)

 /*
  *	dma_map_area(start, size, dir)
  *	- start	- kernel virtual start address
  *	- size	- size of region
  *	- dir	- DMA direction
  */
 ENTRY(v7_dma_map_area)
 	add	r1, r1, r0
 	teq	r2, #DMA_FROM_DEVICE
 	beq	v7_dma_inv_range
 	b	v7_dma_clean_range
 ENDPROC(v7_dma_map_area)

 /*
  *	dma_unmap_area(start, size, dir)
  *	- start	- kernel virtual start address
  *	- size	- size of region
  *	- dir	- DMA direction
  */
 ENTRY(v7_dma_unmap_area)
 	add	r1, r1, r0
 	teq	r2, #DMA_TO_DEVICE
 	bne	v7_dma_inv_range
 	mov	pc, lr
 ENDPROC(v7_dma_unmap_area)

 	__INITDATA

 	.type	v7_cache_fns, #object
 ENTRY(v7_cache_fns)
 	.long	v7_flush_icache_all
 	.long	v7_flush_kern_cache_all
 	.long	v7_flush_user_cache_all
 	.long	v7_flush_user_cache_range
 	.long	v7_coherent_kern_range
 	.long	v7_coherent_user_range
 	.long	v7_flush_kern_dcache_area
 	.long	v7_dma_map_area
 	.long	v7_dma_unmap_area
 	.long	v7_dma_flush_range
 	.size	v7_cache_fns, . - v7_cache_fns
	/*
	* linux/arch/arm/mm/cache-v7.S
	*
	* Copyright (C) 2001 Deep Blue Solutions Ltd.
	* Copyright (C) 2005 ARM 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 processor support.
	*/
	#include <linux/linkage.h>
	#include <linux/init.h>
	#include <asm/assembler.h>
	#include <asm/unwind.h>

	#include "proc-macros.S"

	/*
	* v7_flush_icache_all()
	*
	* Flush the whole I-cache.
	*
	* Registers:
	* r0 - set to 0
	*/
	ENTRY(v7_flush_icache_all)
	mov r0, #0
	ALT_SMP(mcr p15, 0, r0, c7, c1, 0) @ invalidate I-cache inner shareable
	ALT_UP(mcr p15, 0, r0, c7, c5, 0) @ I+BTB cache invalidate
	mov pc, lr
	ENDPROC(v7_flush_icache_all)

	/*
	* v7_flush_dcache_all()
	*
	* Flush the whole D-cache.
	*
	* Corrupted registers: r0-r7, r9-r11 (r6 only in Thumb mode)
	*
	* - mm - mm_struct describing address space
	*/
	ENTRY(v7_flush_dcache_all)
	dmb @ ensure ordering with previous memory accesses
	mrc p15, 1, r0, c0, c0, 1 @ read clidr
	ands r3, r0, #0x7000000 @ extract loc from clidr
	mov r3, r3, lsr #23 @ left align loc bit field
	beq finished @ if loc is 0, then no need to clean
	mov r10, #0 @ start clean at cache level 0
	loop1:
	add r2, r10, r10, lsr #1 @ work out 3x current cache level
	mov r1, r0, lsr r2 @ extract cache type bits from clidr
	and r1, r1, #7 @ mask of the bits for current cache only
	cmp r1, #2 @ see what cache we have at this level
	blt skip @ skip if no cache, or just i-cache
	mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
	isb @ isb to sych the new cssr&csidr
	mrc p15, 1, r1, c0, c0, 0 @ read the new csidr
	and r2, r1, #7 @ extract the length of the cache lines
	add r2, r2, #4 @ add 4 (line length offset)
	ldr r4, =0x3ff
	ands r4, r4, r1, lsr #3 @ find maximum number on the way size
	clz r5, r4 @ find bit position of way size increment
	ldr r7, =0x7fff
	ands r7, r7, r1, lsr #13 @ extract max number of the index size
	loop2:
	mov r9, r4 @ create working copy of max way size
	loop3:
	ARM( orr r11, r10, r9, lsl r5 ) @ factor way and cache number into r11
	THUMB( lsl r6, r9, r5 )
	THUMB( orr r11, r10, r6 ) @ factor way and cache number into r11
	ARM( orr r11, r11, r7, lsl r2 ) @ factor index number into r11
	THUMB( lsl r6, r7, r2 )
	THUMB( orr r11, r11, r6 ) @ factor index number into r11
	mcr p15, 0, r11, c7, c14, 2 @ clean & invalidate by set/way
	subs r9, r9, #1 @ decrement the way
	bge loop3
	subs r7, r7, #1 @ decrement the index
	bge loop2
	skip:
	add r10, r10, #2 @ increment cache number
	cmp r3, r10
	bgt loop1
	finished:
	mov r10, #0 @ swith back to cache level 0
	mcr p15, 2, r10, c0, c0, 0 @ select current cache level in cssr
	dsb
	isb
	mov pc, lr
	ENDPROC(v7_flush_dcache_all)

	/*
	* v7_flush_cache_all()
	*
	* Flush the entire cache system.
	* The data cache flush is now achieved using atomic clean / invalidates
	* working outwards from L1 cache. This is done using Set/Way based cache
	* maintainance instructions.
	* The instruction cache can still be invalidated back to the point of
	* unification in a single instruction.
	*
	*/
	ENTRY(v7_flush_kern_cache_all)
	ARM( stmfd sp!, {r4-r5, r7, r9-r11, lr} )
	THUMB( stmfd sp!, {r4-r7, r9-r11, lr} )
	bl v7_flush_dcache_all
	mov r0, #0
	ALT_SMP(mcr p15, 0, r0, c7, c1, 0) @ invalidate I-cache inner shareable
	ALT_UP(mcr p15, 0, r0, c7, c5, 0) @ I+BTB cache invalidate
	ARM( ldmfd sp!, {r4-r5, r7, r9-r11, lr} )
	THUMB( ldmfd sp!, {r4-r7, r9-r11, lr} )
	mov pc, lr
	ENDPROC(v7_flush_kern_cache_all)

	/*
	* v7_flush_cache_all()
	*
	* Flush all TLB entries in a particular address space
	*
	* - mm - mm_struct describing address space
	*/
	ENTRY(v7_flush_user_cache_all)
	/FALLTHROUGH/

	/*
	* v7_flush_cache_range(start, end, flags)
	*
	* Flush a range of TLB entries in the specified address space.
	*
	* - start - start address (may not be aligned)
	* - end - end address (exclusive, may not be aligned)
	* - flags - vm_area_struct flags describing address space
	*
	* It is assumed that:
	* - we have a VIPT cache.
	*/
	ENTRY(v7_flush_user_cache_range)
	mov pc, lr
	ENDPROC(v7_flush_user_cache_all)
	ENDPROC(v7_flush_user_cache_range)

	/*
	* v7_coherent_kern_range(start,end)
	*
	* Ensure that the I and D caches are coherent within specified
	* region. This is typically used when code has been written to
	* a memory region, and will be executed.
	*
	* - start - virtual start address of region
	* - end - virtual end address of region
	*
	* It is assumed that:
	* - the Icache does not read data from the write buffer
	*/
	ENTRY(v7_coherent_kern_range)
	/* FALLTHROUGH */

	/*
	* v7_coherent_user_range(start,end)
	*
	* Ensure that the I and D caches are coherent within specified
	* region. This is typically used when code has been written to
	* a memory region, and will be executed.
	*
	* - start - virtual start address of region
	* - end - virtual end address of region
	*
	* It is assumed that:
	* - the Icache does not read data from the write buffer
	*/
	ENTRY(v7_coherent_user_range)
	UNWIND(.fnstart )
	dcache_line_size r2, r3
	sub r3, r2, #1
	bic r12, r0, r3
	1:
	USER( mcr p15, 0, r12, c7, c11, 1 ) @ clean D line to the point of unification
	add r12, r12, r2
	cmp r12, r1
	blo 1b
	dsb
	icache_line_size r2, r3
	sub r3, r2, #1
	bic r12, r0, r3
	2:
	USER( mcr p15, 0, r12, c7, c5, 1 ) @ invalidate I line
	add r12, r12, r2
	cmp r12, r1
	blo 2b
	3:
	mov r0, #0
	ALT_SMP(mcr p15, 0, r0, c7, c1, 6) @ invalidate BTB Inner Shareable
	ALT_UP(mcr p15, 0, r0, c7, c5, 6) @ invalidate BTB
	dsb
	isb
	mov pc, lr

	/*
	* Fault handling for the cache operation above. If the virtual address in r0
	* isn't mapped, just try the next page.
	*/
	9001:
	mov r12, r12, lsr #12
	mov r12, r12, lsl #12
	add r12, r12, #4096
	b 3b
	UNWIND(.fnend )
	ENDPROC(v7_coherent_kern_range)
	ENDPROC(v7_coherent_user_range)

	/*
	* v7_flush_kern_dcache_area(void *addr, size_t size)
	*
	* Ensure that the data held in the page kaddr is written back
	* to the page in question.
	*
	* - addr - kernel address
	* - size - region size
	*/
	ENTRY(v7_flush_kern_dcache_area)
	dcache_line_size r2, r3
	add r1, r0, r1
	1:
	mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D line / unified line
	add r0, r0, r2
	cmp r0, r1
	blo 1b
	dsb
	mov pc, lr
	ENDPROC(v7_flush_kern_dcache_area)

	/*
	* v7_dma_inv_range(start,end)
	*
	* Invalidate the data cache within the specified region; we will
	* be performing a DMA operation in this region and we want to
	* purge old data in the cache.
	*
	* - start - virtual start address of region
	* - end - virtual end address of region
	*/
	v7_dma_inv_range:
	dcache_line_size r2, r3
	sub r3, r2, #1
	tst r0, r3
	bic r0, r0, r3
	mcrne p15, 0, r0, c7, c14, 1 @ clean & invalidate D / U line

	tst r1, r3
	bic r1, r1, r3
	mcrne p15, 0, r1, c7, c14, 1 @ clean & invalidate D / U line
	1:
	mcr p15, 0, r0, c7, c6, 1 @ invalidate D / U line
	add r0, r0, r2
	cmp r0, r1
	blo 1b
	dsb
	mov pc, lr
	ENDPROC(v7_dma_inv_range)

	/*
	* v7_dma_clean_range(start,end)
	* - start - virtual start address of region
	* - end - virtual end address of region
	*/
	v7_dma_clean_range:
	dcache_line_size r2, r3
	sub r3, r2, #1
	bic r0, r0, r3
	1:
	mcr p15, 0, r0, c7, c10, 1 @ clean D / U line
	add r0, r0, r2
	cmp r0, r1
	blo 1b
	dsb
	mov pc, lr
	ENDPROC(v7_dma_clean_range)

	/*
	* v7_dma_flush_range(start,end)
	* - start - virtual start address of region
	* - end - virtual end address of region
	*/
	ENTRY(v7_dma_flush_range)
	dcache_line_size r2, r3
	sub r3, r2, #1
	bic r0, r0, r3
	1:
	mcr p15, 0, r0, c7, c14, 1 @ clean & invalidate D / U line
	add r0, r0, r2
	cmp r0, r1
	blo 1b
	dsb
	mov pc, lr
	ENDPROC(v7_dma_flush_range)

	/*
	* dma_map_area(start, size, dir)
	* - start - kernel virtual start address
	* - size - size of region
	* - dir - DMA direction
	*/
	ENTRY(v7_dma_map_area)
	add r1, r1, r0
	teq r2, #DMA_FROM_DEVICE
	beq v7_dma_inv_range
	b v7_dma_clean_range
	ENDPROC(v7_dma_map_area)

	/*
	* dma_unmap_area(start, size, dir)
	* - start - kernel virtual start address
	* - size - size of region
	* - dir - DMA direction
	*/
	ENTRY(v7_dma_unmap_area)
	add r1, r1, r0
	teq r2, #DMA_TO_DEVICE
	bne v7_dma_inv_range
	mov pc, lr
	ENDPROC(v7_dma_unmap_area)

	__INITDATA

	.type v7_cache_fns, #object
	ENTRY(v7_cache_fns)
	.long v7_flush_icache_all
	.long v7_flush_kern_cache_all
	.long v7_flush_user_cache_all
	.long v7_flush_user_cache_range
	.long v7_coherent_kern_range
	.long v7_coherent_user_range
	.long v7_flush_kern_dcache_area
	.long v7_dma_map_area
	.long v7_dma_unmap_area
	.long v7_dma_flush_range
	.size v7_cache_fns, . - v7_cache_fns