From c75959a6da19df2700556dc76861442e9716317d Mon Sep 17 00:00:00 2001 From: Max Filippov Date: Mon, 25 May 2015 06:55:05 +0300 Subject: xtensa: reimplement DMA API using common helpers - keep existing functionality: don't handle attributes, don't support high memory; - implement scatterlist primitives (map/unmap/sync); - enable DMA API debug. Signed-off-by: Max Filippov --- arch/xtensa/kernel/pci-dma.c | 203 ++++++++++++++++++++++++++++++++++++------- 1 file changed, 173 insertions(+), 30 deletions(-) (limited to 'arch/xtensa/kernel/pci-dma.c') diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c index e8b76b8e4b29..fb75ebf1463a 100644 --- a/arch/xtensa/kernel/pci-dma.c +++ b/arch/xtensa/kernel/pci-dma.c @@ -1,6 +1,4 @@ /* - * arch/xtensa/kernel/pci-dma.c - * * DMA coherent memory allocation. * * This program is free software; you can redistribute it and/or modify it @@ -9,6 +7,7 @@ * option) any later version. * * Copyright (C) 2002 - 2005 Tensilica Inc. + * Copyright (C) 2015 Cadence Design Systems Inc. * * Based on version for i386. * @@ -25,13 +24,107 @@ #include #include +void dma_cache_sync(struct device *dev, void *vaddr, size_t size, + enum dma_data_direction dir) +{ + switch (dir) { + case DMA_BIDIRECTIONAL: + __flush_invalidate_dcache_range((unsigned long)vaddr, size); + break; + + case DMA_FROM_DEVICE: + __invalidate_dcache_range((unsigned long)vaddr, size); + break; + + case DMA_TO_DEVICE: + __flush_dcache_range((unsigned long)vaddr, size); + break; + + case DMA_NONE: + BUG(); + break; + } +} +EXPORT_SYMBOL(dma_cache_sync); + +static void xtensa_sync_single_for_cpu(struct device *dev, + dma_addr_t dma_handle, size_t size, + enum dma_data_direction dir) +{ + void *vaddr; + + switch (dir) { + case DMA_BIDIRECTIONAL: + case DMA_FROM_DEVICE: + vaddr = bus_to_virt(dma_handle); + __invalidate_dcache_range((unsigned long)vaddr, size); + break; + + case DMA_NONE: + BUG(); + break; + + default: + break; + } +} + +static void xtensa_sync_single_for_device(struct device *dev, + dma_addr_t dma_handle, size_t size, + enum dma_data_direction dir) +{ + void *vaddr; + + switch (dir) { + case DMA_BIDIRECTIONAL: + case DMA_TO_DEVICE: + vaddr = bus_to_virt(dma_handle); + __flush_dcache_range((unsigned long)vaddr, size); + break; + + case DMA_NONE: + BUG(); + break; + + default: + break; + } +} + +static void xtensa_sync_sg_for_cpu(struct device *dev, + struct scatterlist *sg, int nents, + enum dma_data_direction dir) +{ + struct scatterlist *s; + int i; + + for_each_sg(sg, s, nents, i) { + xtensa_sync_single_for_cpu(dev, sg_dma_address(s), + sg_dma_len(s), dir); + } +} + +static void xtensa_sync_sg_for_device(struct device *dev, + struct scatterlist *sg, int nents, + enum dma_data_direction dir) +{ + struct scatterlist *s; + int i; + + for_each_sg(sg, s, nents, i) { + xtensa_sync_single_for_device(dev, sg_dma_address(s), + sg_dma_len(s), dir); + } +} + /* * Note: We assume that the full memory space is always mapped to 'kseg' * Otherwise we have to use page attributes (not implemented). */ -void * -dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag) +static void *xtensa_dma_alloc(struct device *dev, size_t size, + dma_addr_t *handle, gfp_t flag, + struct dma_attrs *attrs) { unsigned long ret; unsigned long uncached = 0; @@ -52,20 +145,15 @@ dma_alloc_coherent(struct device *dev,size_t size,dma_addr_t *handle,gfp_t flag) BUG_ON(ret < XCHAL_KSEG_CACHED_VADDR || ret > XCHAL_KSEG_CACHED_VADDR + XCHAL_KSEG_SIZE - 1); + uncached = ret + XCHAL_KSEG_BYPASS_VADDR - XCHAL_KSEG_CACHED_VADDR; + *handle = virt_to_bus((void *)ret); + __invalidate_dcache_range(ret, size); - if (ret != 0) { - memset((void*) ret, 0, size); - uncached = ret+XCHAL_KSEG_BYPASS_VADDR-XCHAL_KSEG_CACHED_VADDR; - *handle = virt_to_bus((void*)ret); - __flush_invalidate_dcache_range(ret, size); - } - - return (void*)uncached; + return (void *)uncached; } -EXPORT_SYMBOL(dma_alloc_coherent); -void dma_free_coherent(struct device *hwdev, size_t size, - void *vaddr, dma_addr_t dma_handle) +static void xtensa_dma_free(struct device *hwdev, size_t size, void *vaddr, + dma_addr_t dma_handle, struct dma_attrs *attrs) { unsigned long addr = (unsigned long)vaddr + XCHAL_KSEG_CACHED_VADDR - XCHAL_KSEG_BYPASS_VADDR; @@ -75,24 +163,79 @@ void dma_free_coherent(struct device *hwdev, size_t size, free_pages(addr, get_order(size)); } -EXPORT_SYMBOL(dma_free_coherent); +static dma_addr_t xtensa_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + dma_addr_t dma_handle = page_to_phys(page) + offset; + + BUG_ON(PageHighMem(page)); + xtensa_sync_single_for_device(dev, dma_handle, size, dir); + return dma_handle; +} -void consistent_sync(void *vaddr, size_t size, int direction) +static void xtensa_unmap_page(struct device *dev, dma_addr_t dma_handle, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) { - switch (direction) { - case PCI_DMA_NONE: - BUG(); - case PCI_DMA_FROMDEVICE: /* invalidate only */ - __invalidate_dcache_range((unsigned long)vaddr, - (unsigned long)size); - break; + xtensa_sync_single_for_cpu(dev, dma_handle, size, dir); +} - case PCI_DMA_TODEVICE: /* writeback only */ - case PCI_DMA_BIDIRECTIONAL: /* writeback and invalidate */ - __flush_invalidate_dcache_range((unsigned long)vaddr, - (unsigned long)size); - break; +static int xtensa_map_sg(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct scatterlist *s; + int i; + + for_each_sg(sg, s, nents, i) { + s->dma_address = xtensa_map_page(dev, sg_page(s), s->offset, + s->length, dir, attrs); + } + return nents; +} + +static void xtensa_unmap_sg(struct device *dev, + struct scatterlist *sg, int nents, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + struct scatterlist *s; + int i; + + for_each_sg(sg, s, nents, i) { + xtensa_unmap_page(dev, sg_dma_address(s), + sg_dma_len(s), dir, attrs); } } -EXPORT_SYMBOL(consistent_sync); + +int xtensa_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) +{ + return 0; +} + +struct dma_map_ops xtensa_dma_map_ops = { + .alloc = xtensa_dma_alloc, + .free = xtensa_dma_free, + .map_page = xtensa_map_page, + .unmap_page = xtensa_unmap_page, + .map_sg = xtensa_map_sg, + .unmap_sg = xtensa_unmap_sg, + .sync_single_for_cpu = xtensa_sync_single_for_cpu, + .sync_single_for_device = xtensa_sync_single_for_device, + .sync_sg_for_cpu = xtensa_sync_sg_for_cpu, + .sync_sg_for_device = xtensa_sync_sg_for_device, + .mapping_error = xtensa_dma_mapping_error, +}; +EXPORT_SYMBOL(xtensa_dma_map_ops); + +#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16) + +static int __init xtensa_dma_init(void) +{ + dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); + return 0; +} +fs_initcall(xtensa_dma_init); -- cgit