1 files changed, 396 insertions, 0 deletions
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
new file mode 100644
index 000000000..609d1241b
--- /dev/null
+++ b/arch/mips/mm/dma-default.c
@@ -0,0 +1,396 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2000  Ani Joshi <ajoshi@unixbox.com>
+ * Copyright (C) 2000, 2001, 06	 Ralf Baechle <ralf@linux-mips.org>
+ * swiped from i386, and cloned for MIPS by Geert, polished by Ralf.
+ */
+
+#include <linux/types.h>
+#include <linux/dma-mapping.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <linux/string.h>
+#include <linux/gfp.h>
+#include <linux/highmem.h>
+#include <linux/dma-contiguous.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)
+{
+	return pfn_to_page(
+		plat_dma_addr_to_phys(dev, dma_addr) >> PAGE_SHIFT);
+}
+
+/*
+ * 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.
+ *
+ * Note that the R14000 and R16000 should also be checked for in this
+ * condition.  However this function is only called on non-I/O-coherent
+ * systems and only the R10000 and R12000 are used in such systems, the
+ * SGI IP28 Indigo² rsp. SGI IP32 aka O2.
+ */
+static inline int cpu_needs_post_dma_flush(struct device *dev)
+{
+	return !plat_device_is_coherent(dev) &&
+	       (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)
+{
+	gfp_t dma_flag;
+
+	/* ignore region specifiers */
+	gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
+
+#ifdef CONFIG_ISA
+	if (dev == NULL)
+		dma_flag = __GFP_DMA;
+	else
+#endif
+#if defined(CONFIG_ZONE_DMA32) && defined(CONFIG_ZONE_DMA)
+	     if (dev->coherent_dma_mask < DMA_BIT_MASK(32))
+			dma_flag = __GFP_DMA;
+	else if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
+			dma_flag = __GFP_DMA32;
+	else
+#endif
+#if defined(CONFIG_ZONE_DMA32) && !defined(CONFIG_ZONE_DMA)
+	     if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
+		dma_flag = __GFP_DMA32;
+	else
+#endif
+#if defined(CONFIG_ZONE_DMA) && !defined(CONFIG_ZONE_DMA32)
+	     if (dev->coherent_dma_mask < DMA_BIT_MASK(64))
+		dma_flag = __GFP_DMA;
+	else
+#endif
+		dma_flag = 0;
+
+	/* Don't invoke OOM killer */
+	gfp |= __GFP_NORETRY;
+
+	return gfp | dma_flag;
+}
+
+void *dma_alloc_noncoherent(struct device *dev, size_t size,
+	dma_addr_t * dma_handle, gfp_t gfp)
+{
+	void *ret;
+
+	gfp = massage_gfp_flags(dev, gfp);
+
+	ret = (void *) __get_free_pages(gfp, get_order(size));
+
+	if (ret != NULL) {
+		memset(ret, 0, size);
+		*dma_handle = plat_map_dma_mem(dev, ret, size);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(dma_alloc_noncoherent);
+
+static void *mips_dma_alloc_coherent(struct device *dev, size_t size,
+	dma_addr_t * dma_handle, gfp_t gfp, struct dma_attrs *attrs)
+{
+	void *ret;
+	struct page *page = NULL;
+	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+	if (dma_alloc_from_coherent(dev, size, dma_handle, &ret))
+		return ret;
+
+	gfp = massage_gfp_flags(dev, gfp);
+
+	if (IS_ENABLED(CONFIG_DMA_CMA) && !(gfp & GFP_ATOMIC))
+		page = dma_alloc_from_contiguous(dev,
+					count, get_order(size));
+	if (!page)
+		page = alloc_pages(gfp, get_order(size));
+
+	if (!page)
+		return NULL;
+
+	ret = page_address(page);
+	memset(ret, 0, size);
+	*dma_handle = plat_map_dma_mem(dev, ret, size);
+	if (!plat_device_is_coherent(dev)) {
+		dma_cache_wback_inv((unsigned long) ret, size);
+		if (!hw_coherentio)
+			ret = UNCAC_ADDR(ret);
+	}
+
+	return ret;
+}
+
+
+void dma_free_noncoherent(struct device *dev, size_t size, void *vaddr,
+	dma_addr_t dma_handle)
+{
+	plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
+	free_pages((unsigned long) vaddr, get_order(size));
+}
+EXPORT_SYMBOL(dma_free_noncoherent);
+
+static void mips_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
+	dma_addr_t dma_handle, struct dma_attrs *attrs)
+{
+	unsigned long addr = (unsigned long) vaddr;
+	int order = get_order(size);
+	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	struct page *page = NULL;
+
+	if (dma_release_from_coherent(dev, order, vaddr))
+		return;
+
+	plat_unmap_dma_mem(dev, dma_handle, size, DMA_BIDIRECTIONAL);
+
+	if (!plat_device_is_coherent(dev) && !hw_coherentio)
+		addr = CAC_ADDR(addr);
+
+	page = virt_to_page((void *) addr);
+
+	if (!dma_release_from_contiguous(dev, page, count))
+		__free_pages(page, get_order(size));
+}
+
+static inline void __dma_sync_virtual(void *addr, size_t size,
+	enum dma_data_direction direction)
+{
+	switch (direction) {
+	case DMA_TO_DEVICE:
+		dma_cache_wback((unsigned long)addr, size);
+		break;
+
+	case DMA_FROM_DEVICE:
+		dma_cache_inv((unsigned long)addr, size);
+		break;
+
+	case DMA_BIDIRECTIONAL:
+		dma_cache_wback_inv((unsigned long)addr, size);
+		break;
+
+	default:
+		BUG();
+	}
+}
+
+/*
+ * A single sg entry may refer to multiple physically contiguous
+ * pages. But we still need to process highmem pages individually.
+ * If highmem is not configured then the bulk of this loop gets
+ * optimized out.
+ */
+static inline void __dma_sync(struct page *page,
+	unsigned long offset, size_t size, enum dma_data_direction direction)
+{
+	size_t left = size;
+
+	do {
+		size_t len = left;
+
+		if (PageHighMem(page)) {
+			void *addr;
+
+			if (offset + len > PAGE_SIZE) {
+				if (offset >= PAGE_SIZE) {
+					page += offset >> PAGE_SHIFT;
+					offset &= ~PAGE_MASK;
+				}
+				len = PAGE_SIZE - offset;
+			}
+
+			addr = kmap_atomic(page);
+			__dma_sync_virtual(addr + offset, len, direction);
+			kunmap_atomic(addr);
+		} else
+			__dma_sync_virtual(page_address(page) + offset,
+					   size, direction);
+		offset = 0;
+		page++;
+		left -= len;
+	} while (left);
+}
+
+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_needs_post_dma_flush(dev))
+		__dma_sync(dma_addr_to_page(dev, dma_addr),
+			   dma_addr & ~PAGE_MASK, size, direction);
+	plat_post_dma_flush(dev);
+	plat_unmap_dma_mem(dev, dma_addr, size, direction);
+}
+
+static int mips_dma_map_sg(struct device *dev, struct scatterlist *sg,
+	int nents, enum dma_data_direction direction, struct dma_attrs *attrs)
+{
+	int i;
+
+	for (i = 0; i < nents; i++, 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;
+	}
+
+	return nents;
+}
+
+static dma_addr_t mips_dma_map_page(struct device *dev, struct page *page,
+	unsigned long offset, size_t size, enum dma_data_direction direction,
+	struct dma_attrs *attrs)
+{
+	if (!plat_device_is_coherent(dev))
+		__dma_sync(page, offset, size, direction);
+
+	return plat_map_dma_mem_page(dev, page) + offset;
+}
+
+static void mips_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
+	int nhwentries, enum dma_data_direction direction,
+	struct dma_attrs *attrs)
+{
+	int i;
+
+	for (i = 0; i < nhwentries; i++, sg++) {
+		if (!plat_device_is_coherent(dev) &&
+		    direction != DMA_TO_DEVICE)
+			__dma_sync(sg_page(sg), sg->offset, sg->length,
+				   direction);
+		plat_unmap_dma_mem(dev, sg->dma_address, sg->length, direction);
+	}
+}
+
+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_needs_post_dma_flush(dev))
+		__dma_sync(dma_addr_to_page(dev, dma_handle),
+			   dma_handle & ~PAGE_MASK, size, direction);
+	plat_post_dma_flush(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)
+{
+	if (!plat_device_is_coherent(dev))
+		__dma_sync(dma_addr_to_page(dev, dma_handle),
+			   dma_handle & ~PAGE_MASK, size, direction);
+}
+
+static void mips_dma_sync_sg_for_cpu(struct device *dev,
+	struct scatterlist *sg, int nelems, enum dma_data_direction direction)
+{
+	int i;
+
+	if (cpu_needs_post_dma_flush(dev))
+		for (i = 0; i < nelems; i++, sg++)
+			__dma_sync(sg_page(sg), sg->offset, sg->length,
+				   direction);
+	plat_post_dma_flush(dev);
+}
+
+static void mips_dma_sync_sg_for_device(struct device *dev,
+	struct scatterlist *sg, int nelems, enum dma_data_direction direction)
+{
+	int i;
+
+	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 0;
+}
+
+int mips_dma_supported(struct device *dev, u64 mask)
+{
+	return plat_dma_supported(dev, mask);
+}
+
+void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+			 enum dma_data_direction direction)
+{
+	BUG_ON(direction == DMA_NONE);
+
+	if (!plat_device_is_coherent(dev))
+		__dma_sync_virtual(vaddr, size, direction);
+}
+
+EXPORT_SYMBOL(dma_cache_sync);
+
+static struct dma_map_ops mips_default_dma_map_ops = {
+	.alloc = mips_dma_alloc_coherent,
+	.free = mips_dma_free_coherent,
+	.map_page = mips_dma_map_page,
+	.unmap_page = mips_dma_unmap_page,
+	.map_sg = mips_dma_map_sg,
+	.unmap_sg = mips_dma_unmap_sg,
+	.sync_single_for_cpu = mips_dma_sync_single_for_cpu,
+	.sync_single_for_device = mips_dma_sync_single_for_device,
+	.sync_sg_for_cpu = mips_dma_sync_sg_for_cpu,
+	.sync_sg_for_device = mips_dma_sync_sg_for_device,
+	.mapping_error = mips_dma_mapping_error,
+	.dma_supported = mips_dma_supported
+};
+
+struct dma_map_ops *mips_dma_map_ops = &mips_default_dma_map_ops;
+EXPORT_SYMBOL(mips_dma_map_ops);
+
+#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
+
+static int __init mips_dma_init(void)
+{
+	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
+
+	return 0;
+}
+fs_initcall(mips_dma_init);