1 files changed, 346 insertions, 0 deletions
diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c
new file mode 100644
index 00000000000..29711445c81
--- /dev/null
+++ b/arch/x86/kernel/pci-dma_64.c
@@ -0,0 +1,346 @@
+/*
+ * 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>
+#include <asm/iommu.h>
+#include <asm/calgary.h>
+
+int iommu_merge __read_mostly = 0;
+EXPORT_SYMBOL(iommu_merge);
+
+dma_addr_t bad_dma_address __read_mostly;
+EXPORT_SYMBOL(bad_dma_address);
+
+/* This tells the BIO block layer to assume merging. Default to off
+   because we cannot guarantee merging later. */
+int iommu_bio_merge __read_mostly = 0;
+EXPORT_SYMBOL(iommu_bio_merge);
+
+static int iommu_sac_force __read_mostly = 0;
+
+int no_iommu __read_mostly;
+#ifdef CONFIG_IOMMU_DEBUG
+int panic_on_overflow __read_mostly = 1;
+int force_iommu __read_mostly = 1;
+#else
+int panic_on_overflow __read_mostly = 0;
+int force_iommu __read_mostly= 0;
+#endif
+
+/* Set this to 1 if there is a HW IOMMU in the system */
+int iommu_detected __read_mostly = 0;
+
+/* Dummy device used for NULL arguments (normally ISA). Better would
+   be probably a smaller DMA mask, but this is bug-to-bug compatible
+   to i386. */
+struct device fallback_dev = {
+	.bus_id = "fallback device",
+	.coherent_dma_mask = DMA_32BIT_MASK,
+	.dma_mask = &fallback_dev.coherent_dma_mask,
+};
+
+/* Allocate DMA memory on node near device */
+noinline static void *
+dma_alloc_pages(struct device *dev, gfp_t gfp, unsigned order)
+{
+	struct page *page;
+	int node;
+#ifdef CONFIG_PCI
+	if (dev->bus == &pci_bus_type)
+		node = pcibus_to_node(to_pci_dev(dev)->bus);
+	else
+#endif
+		node = numa_node_id();
+
+	if (node < first_node(node_online_map))
+		node = first_node(node_online_map);
+
+	page = alloc_pages_node(node, gfp, order);
+	return page ? page_address(page) : NULL;
+}
+
+/*
+ * Allocate memory for a coherent mapping.
+ */
+void *
+dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		   gfp_t gfp)
+{
+	void *memory;
+	unsigned long dma_mask = 0;
+	u64 bus;
+
+	if (!dev)
+		dev = &fallback_dev;
+	dma_mask = dev->coherent_dma_mask;
+	if (dma_mask == 0)
+		dma_mask = DMA_32BIT_MASK;
+
+	/* Device not DMA able */
+	if (dev->dma_mask == NULL)
+		return NULL;
+
+	/* Don't invoke OOM killer */
+	gfp |= __GFP_NORETRY;
+
+	/* Kludge to make it bug-to-bug compatible with i386. i386
+	   uses the normal dma_mask for alloc_coherent. */
+	dma_mask &= *dev->dma_mask;
+
+	/* Why <=? Even when the mask is smaller than 4GB it is often
+	   larger than 16MB and in this case we have a chance of
+	   finding fitting memory in the next higher zone first. If
+	   not retry with true GFP_DMA. -AK */
+	if (dma_mask <= DMA_32BIT_MASK)
+		gfp |= GFP_DMA32;
+
+ again:
+	memory = dma_alloc_pages(dev, gfp, get_order(size));
+	if (memory == NULL)
+		return NULL;
+
+	{
+		int high, mmu;
+		bus = virt_to_bus(memory);
+	        high = (bus + size) >= dma_mask;
+		mmu = high;
+		if (force_iommu && !(gfp & GFP_DMA))
+			mmu = 1;
+		else if (high) {
+			free_pages((unsigned long)memory,
+				   get_order(size));
+
+			/* Don't use the 16MB ZONE_DMA unless absolutely
+			   needed. It's better to use remapping first. */
+			if (dma_mask < DMA_32BIT_MASK && !(gfp & GFP_DMA)) {
+				gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
+				goto again;
+			}
+
+			/* Let low level make its own zone decisions */
+			gfp &= ~(GFP_DMA32|GFP_DMA);
+
+			if (dma_ops->alloc_coherent)
+				return dma_ops->alloc_coherent(dev, size,
+							   dma_handle, gfp);
+			return NULL;
+		}
+
+		memset(memory, 0, size);
+		if (!mmu) {
+			*dma_handle = virt_to_bus(memory);
+			return memory;
+		}
+	}
+
+	if (dma_ops->alloc_coherent) {
+		free_pages((unsigned long)memory, get_order(size));
+		gfp &= ~(GFP_DMA|GFP_DMA32);
+		return dma_ops->alloc_coherent(dev, size, dma_handle, gfp);
+	}
+
+	if (dma_ops->map_simple) {
+		*dma_handle = dma_ops->map_simple(dev, memory,
+					      size,
+					      PCI_DMA_BIDIRECTIONAL);
+		if (*dma_handle != bad_dma_address)
+			return memory;
+	}
+
+	if (panic_on_overflow)
+		panic("dma_alloc_coherent: IOMMU overflow by %lu bytes\n",size);
+	free_pages((unsigned long)memory, get_order(size));
+	return NULL;
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+/*
+ * Unmap coherent memory.
+ * The caller must ensure that the device has finished accessing the mapping.
+ */
+void dma_free_coherent(struct device *dev, size_t size,
+			 void *vaddr, dma_addr_t bus)
+{
+	if (dma_ops->unmap_single)
+		dma_ops->unmap_single(dev, bus, size, 0);
+	free_pages((unsigned long)vaddr, get_order(size));
+}
+EXPORT_SYMBOL(dma_free_coherent);
+
+static int forbid_dac __read_mostly;
+
+int dma_supported(struct device *dev, u64 mask)
+{
+#ifdef CONFIG_PCI
+	if (mask > 0xffffffff && forbid_dac > 0) {
+
+
+
+		printk(KERN_INFO "PCI: Disallowing DAC for device %s\n", dev->bus_id);
+		return 0;
+	}
+#endif
+
+	if (dma_ops->dma_supported)
+		return dma_ops->dma_supported(dev, mask);
+
+	/* Copied from i386. Doesn't make much sense, because it will
+	   only work for pci_alloc_coherent.
+	   The caller just has to use GFP_DMA in this case. */
+        if (mask < DMA_24BIT_MASK)
+                return 0;
+
+	/* Tell the device to use SAC when IOMMU force is on.  This
+	   allows the driver to use cheaper accesses in some cases.
+
+	   Problem with this is that if we overflow the IOMMU area and
+	   return DAC as fallback address the device may not handle it
+	   correctly.
+
+	   As a special case some controllers have a 39bit address
+	   mode that is as efficient as 32bit (aic79xx). Don't force
+	   SAC for these.  Assume all masks <= 40 bits are of this
+	   type. Normally this doesn't make any difference, but gives
+	   more gentle handling of IOMMU overflow. */
+	if (iommu_sac_force && (mask >= DMA_40BIT_MASK)) {
+		printk(KERN_INFO "%s: Force SAC with mask %Lx\n", dev->bus_id,mask);
+		return 0;
+	}
+
+	return 1;
+}
+EXPORT_SYMBOL(dma_supported);
+
+int dma_set_mask(struct device *dev, u64 mask)
+{
+	if (!dev->dma_mask || !dma_supported(dev, mask))
+		return -EIO;
+	*dev->dma_mask = mask;
+	return 0;
+}
+EXPORT_SYMBOL(dma_set_mask);
+
+/*
+ * See <Documentation/x86_64/boot-options.txt> for the iommu kernel parameter
+ * documentation.
+ */
+__init int iommu_setup(char *p)
+{
+	iommu_merge = 1;
+
+	if (!p)
+		return -EINVAL;
+
+	while (*p) {
+		if (!strncmp(p,"off",3))
+			no_iommu = 1;
+		/* gart_parse_options has more force support */
+		if (!strncmp(p,"force",5))
+			force_iommu = 1;
+		if (!strncmp(p,"noforce",7)) {
+			iommu_merge = 0;
+			force_iommu = 0;
+		}
+
+		if (!strncmp(p, "biomerge",8)) {
+			iommu_bio_merge = 4096;
+			iommu_merge = 1;
+			force_iommu = 1;
+		}
+		if (!strncmp(p, "panic",5))
+			panic_on_overflow = 1;
+		if (!strncmp(p, "nopanic",7))
+			panic_on_overflow = 0;
+		if (!strncmp(p, "merge",5)) {
+			iommu_merge = 1;
+			force_iommu = 1;
+		}
+		if (!strncmp(p, "nomerge",7))
+			iommu_merge = 0;
+		if (!strncmp(p, "forcesac",8))
+			iommu_sac_force = 1;
+		if (!strncmp(p, "allowdac", 8))
+			forbid_dac = 0;
+		if (!strncmp(p, "nodac", 5))
+			forbid_dac = -1;
+
+#ifdef CONFIG_SWIOTLB
+		if (!strncmp(p, "soft",4))
+			swiotlb = 1;
+#endif
+
+#ifdef CONFIG_IOMMU
+		gart_parse_options(p);
+#endif
+
+#ifdef CONFIG_CALGARY_IOMMU
+		if (!strncmp(p, "calgary", 7))
+			use_calgary = 1;
+#endif /* CONFIG_CALGARY_IOMMU */
+
+		p += strcspn(p, ",");
+		if (*p == ',')
+			++p;
+	}
+	return 0;
+}
+early_param("iommu", iommu_setup);
+
+void __init pci_iommu_alloc(void)
+{
+	/*
+	 * The order of these functions is important for
+	 * fall-back/fail-over reasons
+	 */
+#ifdef CONFIG_IOMMU
+	iommu_hole_init();
+#endif
+
+#ifdef CONFIG_CALGARY_IOMMU
+	detect_calgary();
+#endif
+
+#ifdef CONFIG_SWIOTLB
+	pci_swiotlb_init();
+#endif
+}
+
+static int __init pci_iommu_init(void)
+{
+#ifdef CONFIG_CALGARY_IOMMU
+	calgary_iommu_init();
+#endif
+
+#ifdef CONFIG_IOMMU
+	gart_iommu_init();
+#endif
+
+	no_iommu_init();
+	return 0;
+}
+
+void pci_iommu_shutdown(void)
+{
+	gart_iommu_shutdown();
+}
+
+#ifdef CONFIG_PCI
+/* Many VIA bridges seem to corrupt data for DAC. Disable it here */
+
+static __devinit void via_no_dac(struct pci_dev *dev)
+{
+	if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI && forbid_dac == 0) {
+		printk(KERN_INFO "PCI: VIA PCI bridge detected. Disabling DAC.\n");
+		forbid_dac = 1;
+	}
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID, via_no_dac);
+#endif
+/* Must execute after PCI subsystem */
+fs_initcall(pci_iommu_init);