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authorSamuel Thibault <samuel.thibault@ens-lyon.org>2013-07-27 22:15:01 +0000
committerSamuel Thibault <samuel.thibault@ens-lyon.org>2013-07-27 22:15:01 +0000
commit7996a3d79d55b7f879dfd62e202bbfe2963718d3 (patch)
tree8d9f6759fec4099b9be503c11c7ed174f7204980 /libdde-linux26/contrib/arch/x86/kernel/pci-nommu.c
parent4fbe7358c7747a9165f776eb19addbb9baf7def2 (diff)
really properly move files
Diffstat (limited to 'libdde-linux26/contrib/arch/x86/kernel/pci-nommu.c')
-rw-r--r--libdde-linux26/contrib/arch/x86/kernel/pci-nommu.c96
1 files changed, 96 insertions, 0 deletions
diff --git a/libdde-linux26/contrib/arch/x86/kernel/pci-nommu.c b/libdde-linux26/contrib/arch/x86/kernel/pci-nommu.c
new file mode 100644
index 00000000..c70ab5a5
--- /dev/null
+++ b/libdde-linux26/contrib/arch/x86/kernel/pci-nommu.c
@@ -0,0 +1,96 @@
+/* Fallback functions when the main IOMMU code is not compiled in. This
+ code is roughly equivalent to i386. */
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+#include <linux/string.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
+
+#include <asm/iommu.h>
+#include <asm/processor.h>
+#include <asm/dma.h>
+
+static int
+check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size)
+{
+ if (hwdev && !is_buffer_dma_capable(*hwdev->dma_mask, bus, size)) {
+ if (*hwdev->dma_mask >= DMA_32BIT_MASK)
+ printk(KERN_ERR
+ "nommu_%s: overflow %Lx+%zu of device mask %Lx\n",
+ name, (long long)bus, size,
+ (long long)*hwdev->dma_mask);
+ return 0;
+ }
+ return 1;
+}
+
+static dma_addr_t
+nommu_map_single(struct device *hwdev, phys_addr_t paddr, size_t size,
+ int direction)
+{
+ dma_addr_t bus = paddr;
+ WARN_ON(size == 0);
+ if (!check_addr("map_single", hwdev, bus, size))
+ return bad_dma_address;
+ flush_write_buffers();
+ return bus;
+}
+
+
+/* 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.
+ */
+static int nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
+ int nents, int direction)
+{
+ struct scatterlist *s;
+ int i;
+
+ WARN_ON(nents == 0 || sg[0].length == 0);
+
+ for_each_sg(sg, s, nents, i) {
+ BUG_ON(!sg_page(s));
+ s->dma_address = sg_phys(s);
+ if (!check_addr("map_sg", hwdev, s->dma_address, s->length))
+ return 0;
+ s->dma_length = s->length;
+ }
+ flush_write_buffers();
+ return nents;
+}
+
+static void nommu_free_coherent(struct device *dev, size_t size, void *vaddr,
+ dma_addr_t dma_addr)
+{
+ free_pages((unsigned long)vaddr, get_order(size));
+}
+
+struct dma_mapping_ops nommu_dma_ops = {
+ .alloc_coherent = dma_generic_alloc_coherent,
+ .free_coherent = nommu_free_coherent,
+ .map_single = nommu_map_single,
+ .map_sg = nommu_map_sg,
+ .is_phys = 1,
+};
+
+void __init no_iommu_init(void)
+{
+ if (dma_ops)
+ return;
+
+ force_iommu = 0; /* no HW IOMMU */
+ dma_ops = &nommu_dma_ops;
+}