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Diffstat (limited to 'kernel/arch/arm/mm/cache-v4wt.S')
| -rw-r--r-- | kernel/arch/arm/mm/cache-v4wt.S | 206 |
1 files changed, 206 insertions, 0 deletions
diff --git a/kernel/arch/arm/mm/cache-v4wt.S b/kernel/arch/arm/mm/cache-v4wt.S new file mode 100644 index 000000000..a0982ce49 --- /dev/null +++ b/kernel/arch/arm/mm/cache-v4wt.S @@ -0,0 +1,206 @@ +/* + * linux/arch/arm/mm/cache-v4wt.S + * + * Copyright (C) 1997-2002 Russell king + * + * 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. + * + * ARMv4 write through cache operations support. + * + * We assume that the write buffer is not enabled. + */ +#include <linux/linkage.h> +#include <linux/init.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. + */ +ENTRY(v4wt_flush_icache_all) + mov r0, #0 + mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache + ret lr +ENDPROC(v4wt_flush_icache_all) + +/* + * flush_user_cache_all() + * + * Invalidate all cache entries in a particular address + * space. + */ +ENTRY(v4wt_flush_user_cache_all) + /* FALLTHROUGH */ +/* + * flush_kern_cache_all() + * + * Clean and invalidate the entire cache. + */ +ENTRY(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 + +/* + * 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 + */ +ENTRY(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 + +/* + * 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 + */ +ENTRY(v4wt_coherent_kern_range) + /* FALLTRHOUGH */ + +/* + * 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 + */ +ENTRY(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 + +/* + * 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 + */ +ENTRY(v4wt_flush_kern_dcache_area) + mov r2, #0 + mcr p15, 0, r2, c7, c5, 0 @ invalidate I cache + add r1, r0, r1 + /* fallthrough */ + +/* + * 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 + */ + .globl v4wt_dma_flush_range + .equ v4wt_dma_flush_range, v4wt_dma_inv_range + +/* + * dma_unmap_area(start, size, dir) + * - start - kernel virtual start address + * - size - size of region + * - dir - DMA direction + */ +ENTRY(v4wt_dma_unmap_area) + add r1, r1, r0 + teq r2, #DMA_TO_DEVICE + bne v4wt_dma_inv_range + /* FALLTHROUGH */ + +/* + * dma_map_area(start, size, dir) + * - start - kernel virtual start address + * - size - size of region + * - dir - DMA direction + */ +ENTRY(v4wt_dma_map_area) + ret lr +ENDPROC(v4wt_dma_unmap_area) +ENDPROC(v4wt_dma_map_area) + + .globl v4wt_flush_kern_cache_louis + .equ v4wt_flush_kern_cache_louis, v4wt_flush_kern_cache_all + + __INITDATA + + @ define struct cpu_cache_fns (see <asm/cacheflush.h> and proc-macros.S) + define_cache_functions v4wt |