arch/arm64/mm/cache.S - kernel/mindspeed - Git at Google

 /*
  * Cache maintenance
  *
  * Copyright (C) 2001 Deep Blue Solutions Ltd.
  * Copyright (C) 2012 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 program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */

 #include <linux/errno.h>
 #include <linux/linkage.h>
 #include <linux/init.h>
 #include <asm/assembler.h>
 #include <asm/cpufeature.h>
 #include <asm/alternative-asm.h>

 #include "proc-macros.S"

 /*
  *	__flush_dcache_all()
  *
  *	Flush the whole D-cache.
  *
  *	Corrupted registers: x0-x7, x9-x11
  */
 __flush_dcache_all:
 	dmb	sy				// ensure ordering with previous memory accesses
 	mrs	x0, clidr_el1			// read clidr
 	and	x3, x0, #0x7000000		// extract loc from clidr
 	lsr	x3, x3, #23			// left align loc bit field
 	cbz	x3, finished			// if loc is 0, then no need to clean
 	mov	x10, #0				// start clean at cache level 0
 loop1:
 	add	x2, x10, x10, lsr #1		// work out 3x current cache level
 	lsr	x1, x0, x2			// extract cache type bits from clidr
 	and	x1, x1, #7			// mask of the bits for current cache only
 	cmp	x1, #2				// see what cache we have at this level
 	b.lt	skip				// skip if no cache, or just i-cache
 	save_and_disable_irqs x9		// make CSSELR and CCSIDR access atomic
 	msr	csselr_el1, x10			// select current cache level in csselr
 	isb					// isb to sych the new cssr&csidr
 	mrs	x1, ccsidr_el1			// read the new ccsidr
 	restore_irqs x9
 	and	x2, x1, #7			// extract the length of the cache lines
 	add	x2, x2, #4			// add 4 (line length offset)
 	mov	x4, #0x3ff
 	and	x4, x4, x1, lsr #3		// find maximum number on the way size
 	clz	w5, w4				// find bit position of way size increment
 	mov	x7, #0x7fff
 	and	x7, x7, x1, lsr #13		// extract max number of the index size
 loop2:
 	mov	x9, x4				// create working copy of max way size
 loop3:
 	lsl	x6, x9, x5
 	orr	x11, x10, x6			// factor way and cache number into x11
 	lsl	x6, x7, x2
 	orr	x11, x11, x6			// factor index number into x11
 	dc	cisw, x11			// clean & invalidate by set/way
 	subs	x9, x9, #1			// decrement the way
 	b.ge	loop3
 	subs	x7, x7, #1			// decrement the index
 	b.ge	loop2
 skip:
 	add	x10, x10, #2			// increment cache number
 	cmp	x3, x10
 	b.gt	loop1
 finished:
 	mov	x10, #0				// swith back to cache level 0
 	msr	csselr_el1, x10			// select current cache level in csselr
 	dsb	sy
 	isb
 	ret
 ENDPROC(__flush_dcache_all)

 /*
  *	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(flush_cache_all)
 	mov	x12, lr
 	bl	__flush_dcache_all
 	mov	x0, #0
 	ic	ialluis				// I+BTB cache invalidate
 	ret	x12
 ENDPROC(flush_cache_all)

 /*
  *	flush_icache_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
  */
 ENTRY(flush_icache_range)
 	/* FALLTHROUGH */

 /*
  *	__flush_cache_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
  */
 ENTRY(__flush_cache_user_range)
 	dcache_line_size x2, x3
 	sub	x3, x2, #1
 	bic	x4, x0, x3
 1:
 USER(9f, dc	cvau, x4	)		// clean D line to PoU
 	add	x4, x4, x2
 	cmp	x4, x1
 	b.lo	1b
 	dsb	ish

 	icache_line_size x2, x3
 	sub	x3, x2, #1
 	bic	x4, x0, x3
 1:
 USER(9f, ic	ivau, x4	)		// invalidate I line PoU
 	add	x4, x4, x2
 	cmp	x4, x1
 	b.lo	1b
 	dsb	ish
 	isb
 	mov	x0, #0
 	ret
 9:
 	mov	x0, #-EFAULT
 	ret
 ENDPROC(flush_icache_range)
 ENDPROC(__flush_cache_user_range)

 /*
  *	__flush_dcache_area(kaddr, size)
  *
  *	Ensure that the data held in the page kaddr is written back to the
  *	page in question.
  *
  *	- kaddr   - kernel address
  *	- size    - size in question
  */
 ENTRY(__flush_dcache_area)
 	dcache_line_size x2, x3
 	add	x1, x0, x1
 	sub	x3, x2, #1
 	bic	x0, x0, x3
 1:	dc	civac, x0			// clean & invalidate D line / unified line
 	add	x0, x0, x2
 	cmp	x0, x1
 	b.lo	1b
 	dsb	sy
 	ret
 ENDPROC(__flush_dcache_area)

 /*
  *	__inval_cache_range(start, end)
  *	- start   - start address of region
  *	- end     - end address of region
  */
 ENTRY(__inval_cache_range)
 	/* FALLTHROUGH */

 /*
  *	__dma_inv_range(start, end)
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  */
 __dma_inv_range:
 	dcache_line_size x2, x3
 	sub	x3, x2, #1
 	tst	x1, x3				// end cache line aligned?
 	bic	x1, x1, x3
 	b.eq	1f
 	dc	civac, x1			// clean & invalidate D / U line
 1:	tst	x0, x3				// start cache line aligned?
 	bic	x0, x0, x3
 	b.eq	2f
 	dc	civac, x0			// clean & invalidate D / U line
 	b	3f
 2:	dc	ivac, x0			// invalidate D / U line
 3:	add	x0, x0, x2
 	cmp	x0, x1
 	b.lo	2b
 	dsb	sy
 	ret
 ENDPROC(__inval_cache_range)
 ENDPROC(__dma_inv_range)

 /*
  *	__dma_clean_range(start, end)
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  */
 __dma_clean_range:
 	dcache_line_size x2, x3
 	sub	x3, x2, #1
 	bic	x0, x0, x3
 1:	alternative_insn "dc cvac, x0", "dc civac, x0", ARM64_WORKAROUND_CLEAN_CACHE
 	add	x0, x0, x2
 	cmp	x0, x1
 	b.lo	1b
 	dsb	sy
 	ret
 ENDPROC(__dma_clean_range)

 /*
  *	__dma_flush_range(start, end)
  *	- start   - virtual start address of region
  *	- end     - virtual end address of region
  */
 ENTRY(__dma_flush_range)
 	dcache_line_size x2, x3
 	sub	x3, x2, #1
 	bic	x0, x0, x3
 1:	dc	civac, x0			// clean & invalidate D / U line
 	add	x0, x0, x2
 	cmp	x0, x1
 	b.lo	1b
 	dsb	sy
 	ret
 ENDPROC(__dma_flush_range)

 /*
  *	__dma_map_area(start, size, dir)
  *	- start	- kernel virtual start address
  *	- size	- size of region
  *	- dir	- DMA direction
  */
 ENTRY(__dma_map_area)
 	add	x1, x1, x0
 	cmp	w2, #DMA_FROM_DEVICE
 	b.eq	__dma_inv_range
 	b	__dma_clean_range
 ENDPROC(__dma_map_area)

 /*
  *	__dma_unmap_area(start, size, dir)
  *	- start	- kernel virtual start address
  *	- size	- size of region
  *	- dir	- DMA direction
  */
 ENTRY(__dma_unmap_area)
 	add	x1, x1, x0
 	cmp	w2, #DMA_TO_DEVICE
 	b.ne	__dma_inv_range
 	ret
 ENDPROC(__dma_unmap_area)
	/*
	* Cache maintenance
	*
	* Copyright (C) 2001 Deep Blue Solutions Ltd.
	* Copyright (C) 2012 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 program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program. If not, see <http://www.gnu.org/licenses/>.
	*/

	#include <linux/errno.h>
	#include <linux/linkage.h>
	#include <linux/init.h>
	#include <asm/assembler.h>
	#include <asm/cpufeature.h>
	#include <asm/alternative-asm.h>

	#include "proc-macros.S"

	/*
	* __flush_dcache_all()
	*
	* Flush the whole D-cache.
	*
	* Corrupted registers: x0-x7, x9-x11
	*/
	__flush_dcache_all:
	dmb sy // ensure ordering with previous memory accesses
	mrs x0, clidr_el1 // read clidr
	and x3, x0, #0x7000000 // extract loc from clidr
	lsr x3, x3, #23 // left align loc bit field
	cbz x3, finished // if loc is 0, then no need to clean
	mov x10, #0 // start clean at cache level 0
	loop1:
	add x2, x10, x10, lsr #1 // work out 3x current cache level
	lsr x1, x0, x2 // extract cache type bits from clidr
	and x1, x1, #7 // mask of the bits for current cache only
	cmp x1, #2 // see what cache we have at this level
	b.lt skip // skip if no cache, or just i-cache
	save_and_disable_irqs x9 // make CSSELR and CCSIDR access atomic
	msr csselr_el1, x10 // select current cache level in csselr
	isb // isb to sych the new cssr&csidr
	mrs x1, ccsidr_el1 // read the new ccsidr
	restore_irqs x9
	and x2, x1, #7 // extract the length of the cache lines
	add x2, x2, #4 // add 4 (line length offset)
	mov x4, #0x3ff
	and x4, x4, x1, lsr #3 // find maximum number on the way size
	clz w5, w4 // find bit position of way size increment
	mov x7, #0x7fff
	and x7, x7, x1, lsr #13 // extract max number of the index size
	loop2:
	mov x9, x4 // create working copy of max way size
	loop3:
	lsl x6, x9, x5
	orr x11, x10, x6 // factor way and cache number into x11
	lsl x6, x7, x2
	orr x11, x11, x6 // factor index number into x11
	dc cisw, x11 // clean & invalidate by set/way
	subs x9, x9, #1 // decrement the way
	b.ge loop3
	subs x7, x7, #1 // decrement the index
	b.ge loop2
	skip:
	add x10, x10, #2 // increment cache number
	cmp x3, x10
	b.gt loop1
	finished:
	mov x10, #0 // swith back to cache level 0
	msr csselr_el1, x10 // select current cache level in csselr
	dsb sy
	isb
	ret
	ENDPROC(__flush_dcache_all)

	/*
	* 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(flush_cache_all)
	mov x12, lr
	bl __flush_dcache_all
	mov x0, #0
	ic ialluis // I+BTB cache invalidate
	ret x12
	ENDPROC(flush_cache_all)

	/*
	* flush_icache_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
	*/
	ENTRY(flush_icache_range)
	/* FALLTHROUGH */

	/*
	* __flush_cache_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
	*/
	ENTRY(__flush_cache_user_range)
	dcache_line_size x2, x3
	sub x3, x2, #1
	bic x4, x0, x3
	1:
	USER(9f, dc cvau, x4 ) // clean D line to PoU
	add x4, x4, x2
	cmp x4, x1
	b.lo 1b
	dsb ish

	icache_line_size x2, x3
	sub x3, x2, #1
	bic x4, x0, x3
	1:
	USER(9f, ic ivau, x4 ) // invalidate I line PoU
	add x4, x4, x2
	cmp x4, x1
	b.lo 1b
	dsb ish
	isb
	mov x0, #0
	ret
	9:
	mov x0, #-EFAULT
	ret
	ENDPROC(flush_icache_range)
	ENDPROC(__flush_cache_user_range)

	/*
	* __flush_dcache_area(kaddr, size)
	*
	* Ensure that the data held in the page kaddr is written back to the
	* page in question.
	*
	* - kaddr - kernel address
	* - size - size in question
	*/
	ENTRY(__flush_dcache_area)
	dcache_line_size x2, x3
	add x1, x0, x1
	sub x3, x2, #1
	bic x0, x0, x3
	1: dc civac, x0 // clean & invalidate D line / unified line
	add x0, x0, x2
	cmp x0, x1
	b.lo 1b
	dsb sy
	ret
	ENDPROC(__flush_dcache_area)

	/*
	* __inval_cache_range(start, end)
	* - start - start address of region
	* - end - end address of region
	*/
	ENTRY(__inval_cache_range)
	/* FALLTHROUGH */

	/*
	* __dma_inv_range(start, end)
	* - start - virtual start address of region
	* - end - virtual end address of region
	*/
	__dma_inv_range:
	dcache_line_size x2, x3
	sub x3, x2, #1
	tst x1, x3 // end cache line aligned?
	bic x1, x1, x3
	b.eq 1f
	dc civac, x1 // clean & invalidate D / U line
	1: tst x0, x3 // start cache line aligned?
	bic x0, x0, x3
	b.eq 2f
	dc civac, x0 // clean & invalidate D / U line
	b 3f
	2: dc ivac, x0 // invalidate D / U line
	3: add x0, x0, x2
	cmp x0, x1
	b.lo 2b
	dsb sy
	ret
	ENDPROC(__inval_cache_range)
	ENDPROC(__dma_inv_range)

	/*
	* __dma_clean_range(start, end)
	* - start - virtual start address of region
	* - end - virtual end address of region
	*/
	__dma_clean_range:
	dcache_line_size x2, x3
	sub x3, x2, #1
	bic x0, x0, x3
	1: alternative_insn "dc cvac, x0", "dc civac, x0", ARM64_WORKAROUND_CLEAN_CACHE
	add x0, x0, x2
	cmp x0, x1
	b.lo 1b
	dsb sy
	ret
	ENDPROC(__dma_clean_range)

	/*
	* __dma_flush_range(start, end)
	* - start - virtual start address of region
	* - end - virtual end address of region
	*/
	ENTRY(__dma_flush_range)
	dcache_line_size x2, x3
	sub x3, x2, #1
	bic x0, x0, x3
	1: dc civac, x0 // clean & invalidate D / U line
	add x0, x0, x2
	cmp x0, x1
	b.lo 1b
	dsb sy
	ret
	ENDPROC(__dma_flush_range)

	/*
	* __dma_map_area(start, size, dir)
	* - start - kernel virtual start address
	* - size - size of region
	* - dir - DMA direction
	*/
	ENTRY(__dma_map_area)
	add x1, x1, x0
	cmp w2, #DMA_FROM_DEVICE
	b.eq __dma_inv_range
	b __dma_clean_range
	ENDPROC(__dma_map_area)

	/*
	* __dma_unmap_area(start, size, dir)
	* - start - kernel virtual start address
	* - size - size of region
	* - dir - DMA direction
	*/
	ENTRY(__dma_unmap_area)
	add x1, x1, x0
	cmp w2, #DMA_TO_DEVICE
	b.ne __dma_inv_range
	ret
	ENDPROC(__dma_unmap_area)