On Sat, Jan 11, 2014 at 11:25 PM, Aurelien Jarno <aurelien@xxxxxxxxxxx> wrote: > On Sat, Jan 11, 2014 at 08:50:25PM +0800, Huacai Chen wrote: >> On Thu, Jan 9, 2014 at 8:56 PM, Alex Smith <alex.smith@xxxxxxxxxx> wrote: >> >> > On 08/01/14 02:44, Huacai Chen wrote: >> > >> >> This is probably a workaround because Loongson doesn't support DMA >> >> address above 4GB. If memory is more than 4GB, CONFIG_SWIOTLB and >> >> ZONE_DMA32 should be selected. In this way, DMA pages are allocated >> >> below 4GB preferably. >> >> >> >> However, CONFIG_SWIOTLB+ZONE_DMA32 is not enough, so, we provide a >> >> platform-specific dma_map_ops::set_dma_mask() to make sure each >> >> driver's dma_mask and coherent_dma_mask is below 32-bit. >> >> >> >> Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx> >> >> Signed-off-by: Hongliang Tao <taohl@xxxxxxxxxx> >> >> Signed-off-by: Hua Yan <yanh@xxxxxxxxxx> >> >> --- >> >> arch/mips/include/asm/dma-mapping.h | 5 + >> >> .../mips/include/asm/mach-loongson/dma-coherence.h | 22 +++- >> >> arch/mips/loongson/common/Makefile | 5 + >> >> arch/mips/loongson/common/dma-swiotlb.c | 165 >> >> ++++++++++++++++++++ >> >> 4 files changed, 196 insertions(+), 1 deletions(-) >> >> create mode 100644 arch/mips/loongson/common/dma-swiotlb.c >> >> >> >> diff --git a/arch/mips/include/asm/dma-mapping.h >> >> b/arch/mips/include/asm/dma-mapping.h >> >> index 84238c5..06412aa 100644 >> >> --- a/arch/mips/include/asm/dma-mapping.h >> >> +++ b/arch/mips/include/asm/dma-mapping.h >> >> @@ -49,9 +49,14 @@ static inline int dma_mapping_error(struct device >> >> *dev, u64 mask) >> >> static inline int >> >> dma_set_mask(struct device *dev, u64 mask) >> >> { >> >> + struct dma_map_ops *ops = get_dma_ops(dev); >> >> + >> >> if(!dev->dma_mask || !dma_supported(dev, mask)) >> >> return -EIO; >> >> >> >> + if (ops->set_dma_mask) >> >> + return ops->set_dma_mask(dev, mask); >> >> + >> >> *dev->dma_mask = mask; >> >> >> >> return 0; >> >> diff --git a/arch/mips/include/asm/mach-loongson/dma-coherence.h >> >> b/arch/mips/include/asm/mach-loongson/dma-coherence.h >> >> index aeb2c05..6a90275 100644 >> >> --- a/arch/mips/include/asm/mach-loongson/dma-coherence.h >> >> +++ b/arch/mips/include/asm/mach-loongson/dma-coherence.h >> >> @@ -11,24 +11,40 @@ >> >> #ifndef __ASM_MACH_LOONGSON_DMA_COHERENCE_H >> >> #define __ASM_MACH_LOONGSON_DMA_COHERENCE_H >> >> >> >> +#ifdef CONFIG_SWIOTLB >> >> +#include <linux/swiotlb.h> >> >> +#endif >> >> + >> >> struct device; >> >> >> >> +extern dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr); >> >> +extern phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr); >> >> static inline dma_addr_t plat_map_dma_mem(struct device *dev, void >> >> *addr, >> >> size_t size) >> >> { >> >> +#ifdef CONFIG_CPU_LOONGSON3 >> >> + return virt_to_phys(addr); >> >> +#else >> >> return virt_to_phys(addr) | 0x80000000; >> >> +#endif >> >> } >> >> >> >> static inline dma_addr_t plat_map_dma_mem_page(struct device *dev, >> >> struct page *page) >> >> { >> >> +#ifdef CONFIG_CPU_LOONGSON3 >> >> + return page_to_phys(page); >> >> +#else >> >> return page_to_phys(page) | 0x80000000; >> >> +#endif >> >> } >> >> >> >> static inline unsigned long plat_dma_addr_to_phys(struct device *dev, >> >> dma_addr_t dma_addr) >> >> { >> >> -#if defined(CONFIG_CPU_LOONGSON2F) && defined(CONFIG_64BIT) >> >> +#if defined(CONFIG_CPU_LOONGSON3) && defined(CONFIG_64BIT) >> >> + return dma_addr; >> >> +#elif defined(CONFIG_CPU_LOONGSON2F) && defined(CONFIG_64BIT) >> >> return (dma_addr > 0x8fffffff) ? dma_addr : (dma_addr & >> >> 0x0fffffff); >> >> #else >> >> return dma_addr & 0x7fffffff; >> >> @@ -55,7 +71,11 @@ static inline int plat_dma_supported(struct device >> >> *dev, u64 mask) >> >> >> >> static inline int plat_device_is_coherent(struct device *dev) >> >> { >> >> +#ifdef CONFIG_DMA_NONCOHERENT >> >> return 0; >> >> +#else >> >> + return 1; >> >> +#endif /* CONFIG_DMA_NONCOHERENT */ >> >> } >> >> >> >> #endif /* __ASM_MACH_LOONGSON_DMA_COHERENCE_H */ >> >> diff --git a/arch/mips/loongson/common/Makefile >> >> b/arch/mips/loongson/common/Makefile >> >> index 9e4484c..0bb9cc9 100644 >> >> --- a/arch/mips/loongson/common/Makefile >> >> +++ b/arch/mips/loongson/common/Makefile >> >> @@ -26,3 +26,8 @@ obj-$(CONFIG_CS5536) += cs5536/ >> >> # >> >> >> >> obj-$(CONFIG_LOONGSON_SUSPEND) += pm.o >> >> + >> >> +# >> >> +# Big Memory (SWIOTLB) Support >> >> +# >> >> +obj-$(CONFIG_SWIOTLB) += dma-swiotlb.o >> >> diff --git a/arch/mips/loongson/common/dma-swiotlb.c >> >> b/arch/mips/loongson/common/dma-swiotlb.c >> >> new file mode 100644 >> >> index 0000000..9d5451b >> >> --- /dev/null >> >> +++ b/arch/mips/loongson/common/dma-swiotlb.c >> >> @@ -0,0 +1,165 @@ >> >> +#include <linux/mm.h> >> >> +#include <linux/init.h> >> >> +#include <linux/dma-mapping.h> >> >> +#include <linux/scatterlist.h> >> >> +#include <linux/swiotlb.h> >> >> +#include <linux/bootmem.h> >> >> + >> >> +#include <asm/bootinfo.h> >> >> +#include <dma-coherence.h> >> >> + >> >> +static void *loongson_dma_alloc_coherent(struct device *dev, size_t >> >> size, >> >> + dma_addr_t *dma_handle, gfp_t gfp, struct dma_attrs >> >> *attrs) >> >> +{ >> >> + void *ret; >> >> + >> >> + if (dma_alloc_from_coherent(dev, size, dma_handle, &ret)) >> >> + return ret; >> >> + >> >> + /* ignore region specifiers */ >> >> + gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM); >> >> + >> >> +#ifdef CONFIG_ISA >> >> + if (dev == NULL) >> >> + gfp |= __GFP_DMA; >> >> + else >> >> +#endif >> >> +#ifdef CONFIG_ZONE_DMA >> >> + if (dev->coherent_dma_mask < DMA_BIT_MASK(32)) >> >> + gfp |= __GFP_DMA; >> >> + else >> >> +#endif >> >> +#ifdef CONFIG_ZONE_DMA32 >> >> + /* Loongson-3 only support DMA in the memory below 4GB now */ >> >> + if (dev->coherent_dma_mask < DMA_BIT_MASK(40)) >> >> + gfp |= __GFP_DMA32; >> >> + else >> >> +#endif >> >> + ; >> >> + gfp |= __GFP_NORETRY; >> >> + >> >> + ret = swiotlb_alloc_coherent(dev, size, dma_handle, gfp); >> >> + mb(); >> >> + return ret; >> >> +} >> >> + >> >> +static void loongson_dma_free_coherent(struct device *dev, size_t size, >> >> + void *vaddr, dma_addr_t dma_handle, struct dma_attrs >> >> *attrs) >> >> +{ >> >> + int order = get_order(size); >> >> + >> >> + if (dma_release_from_coherent(dev, order, vaddr)) >> >> + return; >> >> + >> >> + swiotlb_free_coherent(dev, size, vaddr, dma_handle); >> >> +} >> >> + >> >> +static dma_addr_t loongson_dma_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 daddr = swiotlb_map_page(dev, page, offset, size, >> >> + dir, attrs); >> >> + mb(); >> >> + return daddr; >> >> +} >> >> + >> >> +static int loongson_dma_map_sg(struct device *dev, struct scatterlist >> >> *sg, >> >> + int nents, enum dma_data_direction dir, >> >> + struct dma_attrs *attrs) >> >> +{ >> >> + int r = swiotlb_map_sg_attrs(dev, sg, nents, dir, NULL); >> >> + mb(); >> >> + >> >> + return r; >> >> +} >> >> + >> >> +static void loongson_dma_sync_single_for_device(struct device *dev, >> >> + dma_addr_t dma_handle, size_t size, >> >> + enum dma_data_direction dir) >> >> +{ >> >> + swiotlb_sync_single_for_device(dev, dma_handle, size, dir); >> >> + mb(); >> >> +} >> >> + >> >> +static void loongson_dma_sync_sg_for_device(struct device *dev, >> >> + struct scatterlist *sg, int nents, >> >> + enum dma_data_direction dir) >> >> +{ >> >> + swiotlb_sync_sg_for_device(dev, sg, nents, dir); >> >> + mb(); >> >> +} >> >> + >> >> +static dma_addr_t >> >> +loongson_unity_phys_to_dma(struct device *dev, phys_addr_t paddr) >> >> +{ >> >> + return paddr; >> >> +} >> >> + >> >> +static phys_addr_t >> >> +loongson_unity_dma_to_phys(struct device *dev, dma_addr_t daddr) >> >> +{ >> >> + return daddr; >> >> +} >> >> + >> >> +struct loongson_dma_map_ops { >> >> + struct dma_map_ops dma_map_ops; >> >> + dma_addr_t (*phys_to_dma)(struct device *dev, phys_addr_t paddr); >> >> + phys_addr_t (*dma_to_phys)(struct device *dev, dma_addr_t daddr); >> >> +}; >> >> + >> >> +dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr) >> >> +{ >> >> + struct loongson_dma_map_ops *ops = container_of(get_dma_ops(dev), >> >> + struct loongson_dma_map_ops, dma_map_ops); >> >> + >> >> + return ops->phys_to_dma(dev, paddr); >> >> +} >> >> + >> >> +phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr) >> >> +{ >> >> + struct loongson_dma_map_ops *ops = container_of(get_dma_ops(dev), >> >> + struct loongson_dma_map_ops, dma_map_ops); >> >> + >> >> + return ops->dma_to_phys(dev, daddr); >> >> +} >> >> >> > >> > This seems a little bit convoluted. Since phys_to_dma and dma_to_phys will >> > always end up calling the loongson_unity_ functions, I don't see any point >> > in having the loongson_dma_map_ops structure to point to them. You can just >> > implement phys_to_dma and dma_to_phys as inlines in >> > mach-loongson/dma-coherence.h. >> > >> This part comes from arch/mips/cavium-octeon/dma-octeon.c, I think this is >> needed in future. > > On Cavium Octeon you have different mappings depending on the CPU, but > this is not the case on Loongson 3A. So I think that Alex is right and > that it can be simplified. Loongson-3 can work with other northbridge (LS2H) other than RS780 and there are already products. Loongson-3 with LS2H has different mappings than RS780 (but of course the current patchset doesn't support LS2H). Can I keep the code as is? Or I must take Alex's suggestion and modify here until the LS2H patchset? > > -- > Aurelien Jarno GPG: 1024D/F1BCDB73 > aurelien@xxxxxxxxxxx http://www.aurel32.net >