summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/pci-dma_64.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/kernel/pci-dma_64.c')
-rw-r--r--arch/x86/kernel/pci-dma_64.c346
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 0000000..2971144
--- /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);
OpenPOWER on IntegriCloud