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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/arm/mm/cache-v4wt.S
*
* Copyright (C) 1997-2002 Russell king
*
* ARMv4 write through cache operations support.
*
* We assume that the write buffer is not enabled.
*/
#include <linux/linkage.h>
#include <linux/init.h>
#include <linux/cfi_types.h>
#include <asm/assembler.h>
#include <asm/page.h>
#include "proc-macros.S"
/*
* The size of one data cache line.
*/
#define CACHE_DLINESIZE 32
/*
* The number of data cache segments.
*/
#define CACHE_DSEGMENTS 8
/*
* The number of lines in a cache segment.
*/
#define CACHE_DENTRIES 64
/*
* This is the size at which it becomes more efficient to
* clean the whole cache, rather than using the individual
* cache line maintenance instructions.
*
* *** This needs benchmarking
*/
#define CACHE_DLIMIT 16384
/*
* flush_icache_all()
*
* Unconditionally clean and invalidate the entire icache.
*/
SYM_TYPED_FUNC_START(v4wt_flush_icache_all)
mov r0, #0
mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
ret lr
SYM_FUNC_END(v4wt_flush_icache_all)
/*
* flush_user_cache_all()
*
* Invalidate all cache entries in a particular address
* space.
*/
SYM_FUNC_ALIAS(v4wt_flush_user_cache_all, v4wt_flush_kern_cache_all)
/*
* flush_kern_cache_all()
*
* Clean and invalidate the entire cache.
*/
SYM_TYPED_FUNC_START(v4wt_flush_kern_cache_all)
mov r2, #VM_EXEC
mov ip, #0
__flush_whole_cache:
tst r2, #VM_EXEC
mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
ret lr
SYM_FUNC_END(v4wt_flush_kern_cache_all)
/*
* flush_user_cache_range(start, end, flags)
*
* Clean and invalidate a range of cache entries in the specified
* address space.
*
* - start - start address (inclusive, page aligned)
* - end - end address (exclusive, page aligned)
* - flags - vma_area_struct flags describing address space
*/
SYM_TYPED_FUNC_START(v4wt_flush_user_cache_range)
sub r3, r1, r0 @ calculate total size
cmp r3, #CACHE_DLIMIT
bhs __flush_whole_cache
1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
tst r2, #VM_EXEC
mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
ret lr
SYM_FUNC_END(v4wt_flush_user_cache_range)
/*
* coherent_kern_range(start, end)
*
* Ensure coherency between the Icache and the Dcache in the
* region described by start. If you have non-snooping
* Harvard caches, you need to implement this function.
*
* - start - virtual start address
* - end - virtual end address
*/
SYM_TYPED_FUNC_START(v4wt_coherent_kern_range)
#ifdef CONFIG_CFI_CLANG /* Fallthrough if !CFI */
b v4wt_coherent_user_range
#endif
SYM_FUNC_END(v4wt_coherent_kern_range)
/*
* coherent_user_range(start, end)
*
* Ensure coherency between the Icache and the Dcache in the
* region described by start. If you have non-snooping
* Harvard caches, you need to implement this function.
*
* - start - virtual start address
* - end - virtual end address
*/
SYM_TYPED_FUNC_START(v4wt_coherent_user_range)
bic r0, r0, #CACHE_DLINESIZE - 1
1: mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
mov r0, #0
ret lr
SYM_FUNC_END(v4wt_coherent_user_range)
/*
* flush_kern_dcache_area(void *addr, size_t size)
*
* Ensure no D cache aliasing occurs, either with itself or
* the I cache
*
* - addr - kernel address
* - size - region size
*/
SYM_TYPED_FUNC_START(v4wt_flush_kern_dcache_area)
mov r2, #0
mcr p15, 0, r2, c7, c5, 0 @ invalidate I cache
add r1, r0, r1
b v4wt_dma_inv_range
SYM_FUNC_END(v4wt_flush_kern_dcache_area)
/*
* dma_inv_range(start, end)
*
* Invalidate (discard) the specified virtual address range.
* May not write back any entries. If 'start' or 'end'
* are not cache line aligned, those lines must be written
* back.
*
* - start - virtual start address
* - end - virtual end address
*/
v4wt_dma_inv_range:
bic r0, r0, #CACHE_DLINESIZE - 1
1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
add r0, r0, #CACHE_DLINESIZE
cmp r0, r1
blo 1b
ret lr
/*
* dma_flush_range(start, end)
*
* Clean and invalidate the specified virtual address range.
*
* - start - virtual start address
* - end - virtual end address
*/
SYM_TYPED_FUNC_START(v4wt_dma_flush_range)
b v4wt_dma_inv_range
SYM_FUNC_END(v4wt_dma_flush_range)
/*
* dma_unmap_area(start, size, dir)
* - start - kernel virtual start address
* - size - size of region
* - dir - DMA direction
*/
SYM_TYPED_FUNC_START(v4wt_dma_unmap_area)
add r1, r1, r0
teq r2, #DMA_TO_DEVICE
bne v4wt_dma_inv_range
ret lr
SYM_FUNC_END(v4wt_dma_unmap_area)
/*
* dma_map_area(start, size, dir)
* - start - kernel virtual start address
* - size - size of region
* - dir - DMA direction
*/
SYM_TYPED_FUNC_START(v4wt_dma_map_area)
ret lr
SYM_FUNC_END(v4wt_dma_map_area)
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