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);
+}
+
+static int loongson_dma_set_mask(struct device *dev, u64 mask)
+{
+ /* Loongson doesn't support DMA above 32-bit */
+ if (mask > DMA_BIT_MASK(32)) {
+ *dev->dma_mask = DMA_BIT_MASK(32);
+ return -EIO;
+ }
+
+ *dev->dma_mask = mask;
+
+ return 0;
+}
+
+static struct loongson_dma_map_ops loongson_linear_dma_map_ops = {
+ .dma_map_ops = {
+ .alloc = loongson_dma_alloc_coherent,
+ .free = loongson_dma_free_coherent,
+ .map_page = loongson_dma_map_page,
+ .unmap_page = swiotlb_unmap_page,
+ .map_sg = loongson_dma_map_sg,
+ .unmap_sg = swiotlb_unmap_sg_attrs,
+ .sync_single_for_cpu = swiotlb_sync_single_for_cpu,
+ .sync_single_for_device = loongson_dma_sync_single_for_device,
+ .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
+ .sync_sg_for_device = loongson_dma_sync_sg_for_device,
+ .mapping_error = swiotlb_dma_mapping_error,
+ .dma_supported = swiotlb_dma_supported,
+ .set_dma_mask = loongson_dma_set_mask
+ },
+ .phys_to_dma = loongson_unity_phys_to_dma,
+ .dma_to_phys = loongson_unity_dma_to_phys
+};
+
+void __init plat_swiotlb_setup(void)
+{
+ swiotlb_init(1);
+ mips_dma_map_ops = &loongson_linear_dma_map_ops.dma_map_ops;
+}
