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7b749aad1f
Commit 9385/2 introduced a few branches inside function prototypes when using CFI in order to deal with the situation where CFI inserts a few bytes of function information in front of the symbol. This is not good for older CPUs where every cycle counts. Commit 9386/2 alleviated the situation a bit by using aliases for the cache functions with identical signatures. This leaves the coherent cache flush functions *_coherent_kern_range() with these branches to the corresponing *_coherent_user_range() around, since their return type differ and they therefore cannot be aliased. Solve this by a simple ifdef so at least we can use fallthroughs when compiling without CFI enabled. Link: https://lore.kernel.org/linux-arm-kernel/Zi+e9M%2Ff5b%2FSto9H@shell.armlinux.org.uk/ Suggested-by: Ard Biesheuvel <ardb@kernel.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
205 lines
4.8 KiB
ArmAsm
205 lines
4.8 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* linux/arch/arm/mm/cache-v4wt.S
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*
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* Copyright (C) 1997-2002 Russell king
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*
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* ARMv4 write through cache operations support.
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*
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* We assume that the write buffer is not enabled.
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*/
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#include <linux/linkage.h>
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#include <linux/init.h>
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#include <linux/cfi_types.h>
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#include <asm/assembler.h>
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#include <asm/page.h>
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#include "proc-macros.S"
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/*
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* The size of one data cache line.
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*/
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#define CACHE_DLINESIZE 32
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/*
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* The number of data cache segments.
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*/
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#define CACHE_DSEGMENTS 8
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/*
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* The number of lines in a cache segment.
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*/
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#define CACHE_DENTRIES 64
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/*
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* This is the size at which it becomes more efficient to
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* clean the whole cache, rather than using the individual
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* cache line maintenance instructions.
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*
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* *** This needs benchmarking
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*/
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#define CACHE_DLIMIT 16384
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/*
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* flush_icache_all()
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*
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* Unconditionally clean and invalidate the entire icache.
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*/
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SYM_TYPED_FUNC_START(v4wt_flush_icache_all)
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mov r0, #0
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mcr p15, 0, r0, c7, c5, 0 @ invalidate I cache
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ret lr
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SYM_FUNC_END(v4wt_flush_icache_all)
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/*
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* flush_user_cache_all()
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*
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* Invalidate all cache entries in a particular address
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* space.
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*/
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SYM_FUNC_ALIAS(v4wt_flush_user_cache_all, v4wt_flush_kern_cache_all)
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/*
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* flush_kern_cache_all()
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*
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* Clean and invalidate the entire cache.
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*/
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SYM_TYPED_FUNC_START(v4wt_flush_kern_cache_all)
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mov r2, #VM_EXEC
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mov ip, #0
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__flush_whole_cache:
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tst r2, #VM_EXEC
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mcrne p15, 0, ip, c7, c5, 0 @ invalidate I cache
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mcr p15, 0, ip, c7, c6, 0 @ invalidate D cache
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ret lr
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SYM_FUNC_END(v4wt_flush_kern_cache_all)
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/*
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* flush_user_cache_range(start, end, flags)
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*
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* Clean and invalidate a range of cache entries in the specified
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* address space.
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*
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* - start - start address (inclusive, page aligned)
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* - end - end address (exclusive, page aligned)
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* - flags - vma_area_struct flags describing address space
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*/
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SYM_TYPED_FUNC_START(v4wt_flush_user_cache_range)
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sub r3, r1, r0 @ calculate total size
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cmp r3, #CACHE_DLIMIT
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bhs __flush_whole_cache
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1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
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tst r2, #VM_EXEC
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mcrne p15, 0, r0, c7, c5, 1 @ invalidate I entry
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add r0, r0, #CACHE_DLINESIZE
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cmp r0, r1
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blo 1b
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ret lr
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SYM_FUNC_END(v4wt_flush_user_cache_range)
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/*
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* coherent_kern_range(start, end)
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*
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* Ensure coherency between the Icache and the Dcache in the
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* region described by start. If you have non-snooping
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* Harvard caches, you need to implement this function.
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*
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* - start - virtual start address
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* - end - virtual end address
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*/
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SYM_TYPED_FUNC_START(v4wt_coherent_kern_range)
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#ifdef CONFIG_CFI_CLANG /* Fallthrough if !CFI */
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b v4wt_coherent_user_range
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#endif
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SYM_FUNC_END(v4wt_coherent_kern_range)
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/*
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* coherent_user_range(start, end)
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*
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* Ensure coherency between the Icache and the Dcache in the
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* region described by start. If you have non-snooping
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* Harvard caches, you need to implement this function.
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*
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* - start - virtual start address
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* - end - virtual end address
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*/
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SYM_TYPED_FUNC_START(v4wt_coherent_user_range)
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bic r0, r0, #CACHE_DLINESIZE - 1
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1: mcr p15, 0, r0, c7, c5, 1 @ invalidate I entry
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add r0, r0, #CACHE_DLINESIZE
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cmp r0, r1
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blo 1b
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mov r0, #0
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ret lr
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SYM_FUNC_END(v4wt_coherent_user_range)
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/*
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* flush_kern_dcache_area(void *addr, size_t size)
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*
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* Ensure no D cache aliasing occurs, either with itself or
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* the I cache
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*
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* - addr - kernel address
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* - size - region size
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*/
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SYM_TYPED_FUNC_START(v4wt_flush_kern_dcache_area)
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mov r2, #0
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mcr p15, 0, r2, c7, c5, 0 @ invalidate I cache
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add r1, r0, r1
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b v4wt_dma_inv_range
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SYM_FUNC_END(v4wt_flush_kern_dcache_area)
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/*
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* dma_inv_range(start, end)
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*
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* Invalidate (discard) the specified virtual address range.
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* May not write back any entries. If 'start' or 'end'
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* are not cache line aligned, those lines must be written
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* back.
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*
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* - start - virtual start address
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* - end - virtual end address
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*/
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v4wt_dma_inv_range:
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bic r0, r0, #CACHE_DLINESIZE - 1
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1: mcr p15, 0, r0, c7, c6, 1 @ invalidate D entry
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add r0, r0, #CACHE_DLINESIZE
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cmp r0, r1
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blo 1b
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ret lr
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/*
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* dma_flush_range(start, end)
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*
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* Clean and invalidate the specified virtual address range.
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*
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* - start - virtual start address
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* - end - virtual end address
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*/
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SYM_TYPED_FUNC_START(v4wt_dma_flush_range)
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b v4wt_dma_inv_range
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SYM_FUNC_END(v4wt_dma_flush_range)
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/*
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* dma_unmap_area(start, size, dir)
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* - start - kernel virtual start address
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* - size - size of region
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* - dir - DMA direction
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*/
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SYM_TYPED_FUNC_START(v4wt_dma_unmap_area)
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add r1, r1, r0
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teq r2, #DMA_TO_DEVICE
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bne v4wt_dma_inv_range
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ret lr
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SYM_FUNC_END(v4wt_dma_unmap_area)
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/*
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* dma_map_area(start, size, dir)
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* - start - kernel virtual start address
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* - size - size of region
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* - dir - DMA direction
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*/
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SYM_TYPED_FUNC_START(v4wt_dma_map_area)
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ret lr
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SYM_FUNC_END(v4wt_dma_map_area)
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