diff options
Diffstat (limited to 'arch/mips/mm/dma-default.c')
| -rw-r--r-- | arch/mips/mm/dma-default.c | 65 |
1 files changed, 45 insertions, 20 deletions
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c index 3fab2046c8a..44b6dff5aba 100644 --- a/arch/mips/mm/dma-default.c +++ b/arch/mips/mm/dma-default.c @@ -4,7 +4,7 @@ * for more details. * * Copyright (C) 2000 Ani Joshi <ajoshi@unixbox.com> - * Copyright (C) 2000, 2001, 06 Ralf Baechle <ralf@linux-mips.org> + * Copyright (C) 2000, 2001, 06 Ralf Baechle <ralf@linux-mips.org> * swiped from i386, and cloned for MIPS by Geert, polished by Ralf. */ @@ -18,10 +18,33 @@ #include <linux/highmem.h> #include <asm/cache.h> +#include <asm/cpu-type.h> #include <asm/io.h> #include <dma-coherence.h> +#ifdef CONFIG_DMA_MAYBE_COHERENT +int coherentio = 0; /* User defined DMA coherency from command line. */ +EXPORT_SYMBOL_GPL(coherentio); +int hw_coherentio = 0; /* Actual hardware supported DMA coherency setting. */ + +static int __init setcoherentio(char *str) +{ + coherentio = 1; + pr_info("Hardware DMA cache coherency (command line)\n"); + return 0; +} +early_param("coherentio", setcoherentio); + +static int __init setnocoherentio(char *str) +{ + coherentio = 0; + pr_info("Software DMA cache coherency (command line)\n"); + return 0; +} +early_param("nocoherentio", setnocoherentio); +#endif + static inline struct page *dma_addr_to_page(struct device *dev, dma_addr_t dma_addr) { @@ -30,16 +53,20 @@ static inline struct page *dma_addr_to_page(struct device *dev, } /* + * The affected CPUs below in 'cpu_needs_post_dma_flush()' can + * speculatively fill random cachelines with stale data at any time, + * requiring an extra flush post-DMA. + * * Warning on the terminology - Linux calls an uncached area coherent; * MIPS terminology calls memory areas with hardware maintained coherency * coherent. */ - -static inline int cpu_is_noncoherent_r10000(struct device *dev) +static inline int cpu_needs_post_dma_flush(struct device *dev) { return !plat_device_is_coherent(dev) && - (current_cpu_type() == CPU_R10000 || - current_cpu_type() == CPU_R12000); + (boot_cpu_type() == CPU_R10000 || + boot_cpu_type() == CPU_R12000 || + boot_cpu_type() == CPU_BMIPS5000); } static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp) @@ -115,7 +142,8 @@ static void *mips_dma_alloc_coherent(struct device *dev, size_t size, if (!plat_device_is_coherent(dev)) { dma_cache_wback_inv((unsigned long) ret, size); - ret = UNCAC_ADDR(ret); + if (!hw_coherentio) + ret = UNCAC_ADDR(ret); } } @@ -142,7 +170,7 @@ static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr, plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL); - if (!plat_device_is_coherent(dev)) + if (!plat_device_is_coherent(dev) && !hw_coherentio) addr = CAC_ADDR(addr); free_pages(addr, get_order(size)); @@ -209,7 +237,7 @@ static inline void __dma_sync(struct page *page, static void mips_dma_unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size, enum dma_data_direction direction, struct dma_attrs *attrs) { - if (cpu_is_noncoherent_r10000(dev)) + if (cpu_needs_post_dma_flush(dev)) __dma_sync(dma_addr_to_page(dev, dma_addr), dma_addr & ~PAGE_MASK, size, direction); @@ -225,6 +253,9 @@ static int mips_dma_map_sg(struct device *dev, struct scatterlist *sg, if (!plat_device_is_coherent(dev)) __dma_sync(sg_page(sg), sg->offset, sg->length, direction); +#ifdef CONFIG_NEED_SG_DMA_LENGTH + sg->dma_length = sg->length; +#endif sg->dma_address = plat_map_dma_mem_page(dev, sg_page(sg)) + sg->offset; } @@ -260,7 +291,7 @@ static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sg, static void mips_dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction) { - if (cpu_is_noncoherent_r10000(dev)) + if (cpu_needs_post_dma_flush(dev)) __dma_sync(dma_addr_to_page(dev, dma_handle), dma_handle & ~PAGE_MASK, size, direction); } @@ -268,7 +299,6 @@ static void mips_dma_sync_single_for_cpu(struct device *dev, static void mips_dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction) { - plat_extra_sync_for_device(dev); if (!plat_device_is_coherent(dev)) __dma_sync(dma_addr_to_page(dev, dma_handle), dma_handle & ~PAGE_MASK, size, direction); @@ -279,12 +309,10 @@ static void mips_dma_sync_sg_for_cpu(struct device *dev, { int i; - /* Make sure that gcc doesn't leave the empty loop body. */ - for (i = 0; i < nelems; i++, sg++) { - if (cpu_is_noncoherent_r10000(dev)) + if (cpu_needs_post_dma_flush(dev)) + for (i = 0; i < nelems; i++, sg++) __dma_sync(sg_page(sg), sg->offset, sg->length, direction); - } } static void mips_dma_sync_sg_for_device(struct device *dev, @@ -292,17 +320,15 @@ static void mips_dma_sync_sg_for_device(struct device *dev, { int i; - /* Make sure that gcc doesn't leave the empty loop body. */ - for (i = 0; i < nelems; i++, sg++) { - if (!plat_device_is_coherent(dev)) + if (!plat_device_is_coherent(dev)) + for (i = 0; i < nelems; i++, sg++) __dma_sync(sg_page(sg), sg->offset, sg->length, direction); - } } int mips_dma_mapping_error(struct device *dev, dma_addr_t dma_addr) { - return plat_dma_mapping_error(dev, dma_addr); + return 0; } int mips_dma_supported(struct device *dev, u64 mask) @@ -315,7 +341,6 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size, { BUG_ON(direction == DMA_NONE); - plat_extra_sync_for_device(dev); if (!plat_device_is_coherent(dev)) __dma_sync_virtual(vaddr, size, direction); } |