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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/pci-dma.c
downloadconfigs-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/i386/kernel/pci-dma.c')
-rw-r--r--arch/i386/kernel/pci-dma.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/i386/kernel/pci-dma.c b/arch/i386/kernel/pci-dma.c
new file mode 100644
index 00000000000..4de2e03c7b4
--- /dev/null
+++ b/arch/i386/kernel/pci-dma.c
@@ -0,0 +1,147 @@
+/*
+ * Dynamic DMA mapping support.
+ *
+ * On i386 there is no hardware dynamic DMA address translation,
+ * so consistent alloc/free are merely page allocation/freeing.
+ * The rest of the dynamic DMA mapping interface is implemented
+ * in asm/pci.h.
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/pci.h>
+#include <asm/io.h>
+
+struct dma_coherent_mem {
+ void *virt_base;
+ u32 device_base;
+ int size;
+ int flags;
+ unsigned long *bitmap;
+};
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, unsigned int __nocast gfp)
+{
+ void *ret;
+ struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+ int order = get_order(size);
+ /* ignore region specifiers */
+ gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
+
+ if (mem) {
+ int page = bitmap_find_free_region(mem->bitmap, mem->size,
+ order);
+ if (page >= 0) {
+ *dma_handle = mem->device_base + (page << PAGE_SHIFT);
+ ret = mem->virt_base + (page << PAGE_SHIFT);
+ memset(ret, 0, size);
+ return ret;
+ }
+ if (mem->flags & DMA_MEMORY_EXCLUSIVE)
+ return NULL;
+ }
+
+ if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
+ gfp |= GFP_DMA;
+
+ ret = (void *)__get_free_pages(gfp, order);
+
+ if (ret != NULL) {
+ memset(ret, 0, size);
+ *dma_handle = virt_to_phys(ret);
+ }
+ return ret;
+}
+
+void dma_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle)
+{
+ struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+ int order = get_order(size);
+
+ if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
+ int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
+
+ bitmap_release_region(mem->bitmap, page, order);
+ } else
+ free_pages((unsigned long)vaddr, order);
+}
+
+int dma_declare_coherent_memory(struct device *dev, dma_addr_t bus_addr,
+ dma_addr_t device_addr, size_t size, int flags)
+{
+ void __iomem *mem_base;
+ int pages = size >> PAGE_SHIFT;
+ int bitmap_size = (pages + 31)/32;
+
+ if ((flags & (DMA_MEMORY_MAP | DMA_MEMORY_IO)) == 0)
+ goto out;
+ if (!size)
+ goto out;
+ if (dev->dma_mem)
+ goto out;
+
+ /* FIXME: this routine just ignores DMA_MEMORY_INCLUDES_CHILDREN */
+
+ mem_base = ioremap(bus_addr, size);
+ if (!mem_base)
+ goto out;
+
+ dev->dma_mem = kmalloc(sizeof(struct dma_coherent_mem), GFP_KERNEL);
+ if (!dev->dma_mem)
+ goto out;
+ memset(dev->dma_mem, 0, sizeof(struct dma_coherent_mem));
+ dev->dma_mem->bitmap = kmalloc(bitmap_size, GFP_KERNEL);
+ if (!dev->dma_mem->bitmap)
+ goto free1_out;
+ memset(dev->dma_mem->bitmap, 0, bitmap_size);
+
+ dev->dma_mem->virt_base = mem_base;
+ dev->dma_mem->device_base = device_addr;
+ dev->dma_mem->size = pages;
+ dev->dma_mem->flags = flags;
+
+ if (flags & DMA_MEMORY_MAP)
+ return DMA_MEMORY_MAP;
+
+ return DMA_MEMORY_IO;
+
+ free1_out:
+ kfree(dev->dma_mem->bitmap);
+ out:
+ return 0;
+}
+EXPORT_SYMBOL(dma_declare_coherent_memory);
+
+void dma_release_declared_memory(struct device *dev)
+{
+ struct dma_coherent_mem *mem = dev->dma_mem;
+
+ if(!mem)
+ return;
+ dev->dma_mem = NULL;
+ iounmap(mem->virt_base);
+ kfree(mem->bitmap);
+ kfree(mem);
+}
+EXPORT_SYMBOL(dma_release_declared_memory);
+
+void *dma_mark_declared_memory_occupied(struct device *dev,
+ dma_addr_t device_addr, size_t size)
+{
+ struct dma_coherent_mem *mem = dev->dma_mem;
+ int pages = (size + (device_addr & ~PAGE_MASK) + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ int pos, err;
+
+ if (!mem)
+ return ERR_PTR(-EINVAL);
+
+ pos = (device_addr - mem->device_base) >> PAGE_SHIFT;
+ err = bitmap_allocate_region(mem->bitmap, pos, get_order(pages));
+ if (err != 0)
+ return ERR_PTR(err);
+ return mem->virt_base + (pos << PAGE_SHIFT);
+}
+EXPORT_SYMBOL(dma_mark_declared_memory_occupied);