Linux-2.6.12-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!
diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c
new file mode 100644
index 0000000..cab471c
--- /dev/null
+++ b/arch/x86_64/kernel/pci-dma.c
@@ -0,0 +1,60 @@
+/*
+ * Dynamic DMA mapping support.
+ */
+
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/pci.h>
+#include <linux/module.h>
+#include <asm/io.h>
+
+/* Map a set of buffers described by scatterlist in streaming
+ * mode for DMA. This is the scatter-gather version of the
+ * above pci_map_single interface. Here the scatter gather list
+ * elements are each tagged with the appropriate dma address
+ * and length. They are obtained via sg_dma_{address,length}(SG).
+ *
+ * NOTE: An implementation may be able to use a smaller number of
+ * DMA address/length pairs than there are SG table elements.
+ * (for example via virtual mapping capabilities)
+ * The routine returns the number of addr/length pairs actually
+ * used, at most nents.
+ *
+ * Device ownership issues as mentioned above for pci_map_single are
+ * the same here.
+ */
+int dma_map_sg(struct device *hwdev, struct scatterlist *sg,
+ int nents, int direction)
+{
+ int i;
+
+ BUG_ON(direction == DMA_NONE);
+ for (i = 0; i < nents; i++ ) {
+ struct scatterlist *s = &sg[i];
+ BUG_ON(!s->page);
+ s->dma_address = virt_to_bus(page_address(s->page) +s->offset);
+ s->dma_length = s->length;
+ }
+ return nents;
+}
+
+EXPORT_SYMBOL(dma_map_sg);
+
+/* Unmap a set of streaming mode DMA translations.
+ * Again, cpu read rules concerning calls here are the same as for
+ * pci_unmap_single() above.
+ */
+void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
+ int nents, int dir)
+{
+ int i;
+ for (i = 0; i < nents; i++) {
+ struct scatterlist *s = &sg[i];
+ BUG_ON(s->page == NULL);
+ BUG_ON(s->dma_address == 0);
+ dma_unmap_single(dev, s->dma_address, s->dma_length, dir);
+ }
+}
+
+EXPORT_SYMBOL(dma_unmap_sg);