summaryrefslogtreecommitdiffstats
path: root/arch/x86_64/kernel/pci-dma.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86_64/kernel/pci-dma.c')
-rw-r--r--arch/x86_64/kernel/pci-dma.c286
1 files changed, 246 insertions, 40 deletions
diff --git a/arch/x86_64/kernel/pci-dma.c b/arch/x86_64/kernel/pci-dma.c
index cab471cf3ed..2f5d8328e2b 100644
--- a/arch/x86_64/kernel/pci-dma.c
+++ b/arch/x86_64/kernel/pci-dma.c
@@ -8,53 +8,259 @@
#include <linux/pci.h>
#include <linux/module.h>
#include <asm/io.h>
+#include <asm/proto.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 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);
+
+int iommu_sac_force __read_mostly = 0;
+EXPORT_SYMBOL(iommu_sac_force);
+
+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
+
+/* 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 = 0xffffffff,
+ .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;
+ if (dev->bus == &pci_bus_type)
+ node = pcibus_to_node(to_pci_dev(dev)->bus);
+ else
+ node = numa_node_id();
+ page = alloc_pages_node(node, gfp, order);
+ return page ? page_address(page) : NULL;
+}
+
+/*
+ * Allocate memory for a coherent mapping.
*/
-int dma_map_sg(struct device *hwdev, struct scatterlist *sg,
- int nents, int direction)
+void *
+dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
+ gfp_t gfp)
{
- 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;
+ 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 = 0xffffffff;
+
+ /* 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 <= 0xffffffff)
+ 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 < 0xffffffff && !(gfp & GFP_DMA)) {
+ gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
+ goto again;
+ }
+
+ 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;
}
- return nents;
-}
-EXPORT_SYMBOL(dma_map_sg);
+ 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 a set of streaming mode DMA translations.
- * Again, cpu read rules concerning calls here are the same as for
- * pci_unmap_single() above.
+/*
+ * Unmap coherent memory.
+ * The caller must ensure that the device has finished accessing the mapping.
*/
-void dma_unmap_sg(struct device *dev, struct scatterlist *sg,
- int nents, int dir)
+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);
+
+int dma_supported(struct device *dev, u64 mask)
+{
+ 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 < 0x00ffffff)
+ 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 >= 0xffffffffffULL)) {
+ 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)
{
- 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);
- }
+ if (!dev->dma_mask || !dma_supported(dev, mask))
+ return -EIO;
+ *dev->dma_mask = mask;
+ return 0;
}
+EXPORT_SYMBOL(dma_set_mask);
+
+/* iommu=[size][,noagp][,off][,force][,noforce][,leak][,memaper[=order]][,merge]
+ [,forcesac][,fullflush][,nomerge][,biomerge]
+ size set size of iommu (in bytes)
+ noagp don't initialize the AGP driver and use full aperture.
+ off don't use the IOMMU
+ leak turn on simple iommu leak tracing (only when CONFIG_IOMMU_LEAK is on)
+ memaper[=order] allocate an own aperture over RAM with size 32MB^order.
+ noforce don't force IOMMU usage. Default.
+ force Force IOMMU.
+ merge Do lazy merging. This may improve performance on some block devices.
+ Implies force (experimental)
+ biomerge Do merging at the BIO layer. This is more efficient than merge,
+ but should be only done with very big IOMMUs. Implies merge,force.
+ nomerge Don't do SG merging.
+ forcesac For SAC mode for masks <40bits (experimental)
+ fullflush Flush IOMMU on each allocation (default)
+ nofullflush Don't use IOMMU fullflush
+ allowed overwrite iommu off workarounds for specific chipsets.
+ soft Use software bounce buffering (default for Intel machines)
+ noaperture Don't touch the aperture for AGP.
+*/
+__init int iommu_setup(char *p)
+{
+ iommu_merge = 1;
-EXPORT_SYMBOL(dma_unmap_sg);
+ 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;
+
+#ifdef CONFIG_SWIOTLB
+ if (!strncmp(p, "soft",4))
+ swiotlb = 1;
+#endif
+
+#ifdef CONFIG_GART_IOMMU
+ gart_parse_options(p);
+#endif
+
+ p += strcspn(p, ",");
+ if (*p == ',')
+ ++p;
+ }
+ return 1;
+}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-24 08:06:08 +0000