/* SPDX-License-Identifier: GPL-2.0-only */
/*
 *  linux/arch/arm/mm/cache-v4wb.S
 *
 *  Copyright (C) 1997-2002 Russell king
 */
#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 total size of the data cache.
 */
#if defined(CONFIG_CPU_SA110)
# define CACHE_DSIZE    16384
#elif defined(CONFIG_CPU_SA1100)
# define CACHE_DSIZE    8192
#else
# error Unknown cache size
#endif

/*
 * This is the size at which it becomes more efficient to
 * clean the whole cache, rather than using the individual
 * cache line maintenance instructions.
 *
 *  Size  Clean (ticks) Dirty (ticks)
 *   4096   21  20  21    53  55  54
 *   8192   40  41  40   106 100 102
 *  16384   77  77  76   140 140 138
 *  32768  150 149 150   214 216 212 <---
 *  65536  296 297 296   351 358 361
 * 131072  591 591 591   656 657 651
 *  Whole  132 136 132   221 217 207 <---
 */
#define CACHE_DLIMIT    (CACHE_DSIZE * 4)

        .data
        .align  2
flush_base:
        .long   FLUSH_BASE
        .text

/*
 *      flush_icache_all()
 *
 *      Unconditionally clean and invalidate the entire icache.
 */
SYM_TYPED_FUNC_START(v4wb_flush_icache_all)
        mov     r0, #0
        mcr     p15, 0, r0, c7, c5, 0           @ invalidate I cache
        ret     lr
SYM_FUNC_END(v4wb_flush_icache_all)

/*
 *      flush_user_cache_all()
 *
 *      Clean and invalidate all cache entries in a particular address
 *      space.
 */
SYM_FUNC_ALIAS(v4wb_flush_user_cache_all, v4wb_flush_kern_cache_all)

/*
 *      flush_kern_cache_all()
 *
 *      Clean and invalidate the entire cache.
 */
SYM_TYPED_FUNC_START(v4wb_flush_kern_cache_all)
        mov     ip, #0
        mcr     p15, 0, ip, c7, c5, 0           @ invalidate I cache
__flush_whole_cache:
        ldr     r3, =flush_base
        ldr     r1, [r3, #0]
        eor     r1, r1, #CACHE_DSIZE
        str     r1, [r3, #0]
        add     r2, r1, #CACHE_DSIZE
1:      ldr     r3, [r1], #32
        cmp     r1, r2
        blo     1b
#ifdef FLUSH_BASE_MINICACHE
        add     r2, r2, #FLUSH_BASE_MINICACHE - FLUSH_BASE
        sub     r1, r2, #512                    @ only 512 bytes
1:      ldr     r3, [r1], #32
        cmp     r1, r2
        blo     1b
#endif
        mcr     p15, 0, ip, c7, c10, 4          @ drain write buffer
        ret     lr
SYM_FUNC_END(v4wb_flush_kern_cache_all)

/*
 *      flush_user_cache_range(start, end, flags)
 *
 *      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(v4wb_flush_user_cache_range)
        mov     ip, #0
        sub     r3, r1, r0                      @ calculate total size
        tst     r2, #VM_EXEC                    @ executable region?
        mcrne   p15, 0, ip, c7, c5, 0           @ invalidate I cache

        cmp     r3, #CACHE_DLIMIT               @ total size >= limit?
        bhs     __flush_whole_cache             @ flush whole D cache

1:      mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
        mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
        add     r0, r0, #CACHE_DLINESIZE
        cmp     r0, r1
        blo     1b
        tst     r2, #VM_EXEC
        mcrne   p15, 0, ip, c7, c10, 4          @ drain write buffer
        ret     lr
SYM_FUNC_END(v4wb_flush_user_cache_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(v4wb_flush_kern_dcache_area)
        add     r1, r0, r1
#ifdef CONFIG_CFI /* Fallthrough if !CFI */
        b       v4wb_coherent_user_range
#endif
SYM_FUNC_END(v4wb_flush_kern_dcache_area)

/*
 *      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(v4wb_coherent_kern_range)
#ifdef CONFIG_CFI /* Fallthrough if !CFI */
        b       v4wb_coherent_user_range
#endif
SYM_FUNC_END(v4wb_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(v4wb_coherent_user_range)
        bic     r0, r0, #CACHE_DLINESIZE - 1
1:      mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
        mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
        add     r0, r0, #CACHE_DLINESIZE
        cmp     r0, r1
        blo     1b
        mov     r0, #0
        mcr     p15, 0, r0, c7, c5, 0           @ invalidate I cache
        mcr     p15, 0, r0, c7, c10, 4          @ drain WB
        ret     lr
SYM_FUNC_END(v4wb_coherent_user_range)

/*
 *      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
 */
v4wb_dma_inv_range:
        tst     r0, #CACHE_DLINESIZE - 1
        bic     r0, r0, #CACHE_DLINESIZE - 1
        mcrne   p15, 0, r0, c7, c10, 1          @ clean D entry
        tst     r1, #CACHE_DLINESIZE - 1
        mcrne   p15, 0, r1, c7, c10, 1          @ clean D entry
1:      mcr     p15, 0, r0, c7, c6, 1           @ invalidate D entry
        add     r0, r0, #CACHE_DLINESIZE
        cmp     r0, r1
        blo     1b
        mcr     p15, 0, r0, c7, c10, 4          @ drain write buffer
        ret     lr

/*
 *      dma_clean_range(start, end)
 *
 *      Clean (write back) the specified virtual address range.
 *
 *      - start  - virtual start address
 *      - end    - virtual end address
 */
v4wb_dma_clean_range:
        bic     r0, r0, #CACHE_DLINESIZE - 1
1:      mcr     p15, 0, r0, c7, c10, 1          @ clean D entry
        add     r0, r0, #CACHE_DLINESIZE
        cmp     r0, r1
        blo     1b
        mcr     p15, 0, r0, c7, c10, 4          @ drain write buffer
        ret     lr

/*
 *      dma_flush_range(start, end)
 *
 *      Clean and invalidate the specified virtual address range.
 *
 *      - start  - virtual start address
 *      - end    - virtual end address
 *
 *      This is actually the same as v4wb_coherent_kern_range()
 */
        .globl  v4wb_dma_flush_range
        .set    v4wb_dma_flush_range, v4wb_coherent_kern_range

/*
 *      dma_map_area(start, size, dir)
 *      - start - kernel virtual start address
 *      - size  - size of region
 *      - dir   - DMA direction
 */
SYM_TYPED_FUNC_START(v4wb_dma_map_area)
        add     r1, r1, r0
        cmp     r2, #DMA_TO_DEVICE
        beq     v4wb_dma_clean_range
        bcs     v4wb_dma_inv_range
        b       v4wb_dma_flush_range
SYM_FUNC_END(v4wb_dma_map_area)

/*
 *      dma_unmap_area(start, size, dir)
 *      - start - kernel virtual start address
 *      - size  - size of region
 *      - dir   - DMA direction
 */
SYM_TYPED_FUNC_START(v4wb_dma_unmap_area)
        ret     lr
SYM_FUNC_END(v4wb_dma_unmap_area)