X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fx86_64%2Fkernel%2Fpci-nommu.c;h=1f6ecc62061d9121633e53edf672dec81b2da7c3;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=00fb2645c510a32a4ef4c717765b750002124ac0;hpb=5273a3df6485dc2ad6aa7ddd441b9a21970f003b;p=linux-2.6.git

diff --git a/arch/x86_64/kernel/pci-nommu.c b/arch/x86_64/kernel/pci-nommu.c
index 00fb2645c..1f6ecc620 100644
--- a/arch/x86_64/kernel/pci-nommu.c
+++ b/arch/x86_64/kernel/pci-nommu.c
@@ -1,68 +1,93 @@
+/* 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 <asm/proto.h>
+#include <asm/processor.h>
+#include <asm/dma.h>
 
-int iommu_merge = 0;
-EXPORT_SYMBOL(iommu_merge);
-
-dma_addr_t bad_dma_address;
-EXPORT_SYMBOL(bad_dma_address);
-
-/* 
- * Dummy IO MMU functions
- */
-
-void *pci_alloc_consistent(struct pci_dev *hwdev, size_t size,
-			   dma_addr_t *dma_handle)
+static int
+check_addr(char *name, struct device *hwdev, dma_addr_t bus, size_t size)
 {
-	void *ret;
-	int gfp = GFP_ATOMIC;
-	
-	if (hwdev == NULL ||
-	    end_pfn > (hwdev->dma_mask>>PAGE_SHIFT) ||  /* XXX */
-	    (u32)hwdev->dma_mask < 0xffffffff)
-		gfp |= GFP_DMA;
-	ret = (void *)__get_free_pages(gfp, get_order(size));
-
-	if (ret != NULL) {
-		memset(ret, 0, size);
-		*dma_handle = virt_to_bus(ret);
+        if (hwdev && bus + size > *hwdev->dma_mask) {
+		if (*hwdev->dma_mask >= 0xffffffffULL)
+			printk(KERN_ERR
+			    "nommu_%s: overflow %Lx+%lu of device mask %Lx\n",
+	       			name, (long long)bus, size, (long long)*hwdev->dma_mask);
+		return 0;
 	}
-	return ret;
+	return 1;
 }
 
-void pci_free_consistent(struct pci_dev *hwdev, size_t size,
-			 void *vaddr, dma_addr_t dma_handle)
+static dma_addr_t
+nommu_map_single(struct device *hwdev, void *ptr, size_t size,
+	       int direction)
 {
-	free_pages((unsigned long)vaddr, get_order(size));
+	dma_addr_t bus = virt_to_bus(ptr);
+	if (!check_addr("map_single", hwdev, bus, size))
+				return bad_dma_address;
+	return bus;
 }
 
-int pci_dma_supported(struct pci_dev *hwdev, u64 mask)
+void nommu_unmap_single(struct device *dev, dma_addr_t addr,size_t size,
+			int direction)
 {
-        /*
-         * we fall back to GFP_DMA when the mask isn't all 1s,
-         * so we can't guarantee allocations that must be
-         * within a tighter range than GFP_DMA..
-		 * RED-PEN this won't work for pci_map_single. Caller has to
-		 * use GFP_DMA in the first place.
-         */
-        if (mask < 0x00ffffff)
-                return 0;
+}
 
-	return 1;
-} 
+/* 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 nommu_map_sg(struct device *hwdev, struct scatterlist *sg,
+	       int nents, int direction)
+{
+	int i;
 
-EXPORT_SYMBOL(pci_dma_supported);
+	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);
+		if (!check_addr("map_sg", hwdev, s->dma_address, s->length))
+			return 0;
+		s->dma_length = s->length;
+	}
+	return nents;
+}
 
-static int __init check_ram(void) 
-{ 
-	if (end_pfn >= 0xffffffff>>PAGE_SHIFT) { 
-		printk(KERN_ERR "WARNING more than 4GB of memory but no IOMMU.\n"
-		       KERN_ERR "WARNING 32bit PCI may malfunction.\n"); 
-	} 
-	return 0;
-} 
-__initcall(check_ram);
+/* 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 nommu_unmap_sg(struct device *dev, struct scatterlist *sg,
+		  int nents, int dir)
+{
+}
+
+struct dma_mapping_ops nommu_dma_ops = {
+	.map_single = nommu_map_single,
+	.unmap_single = nommu_unmap_single,
+	.map_sg = nommu_map_sg,
+	.unmap_sg = nommu_unmap_sg,
+	.is_phys = 1,
+};
 
+void __init no_iommu_init(void)
+{
+	if (dma_ops)
+		return;
+	dma_ops = &nommu_dma_ops;
+}