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Diffstat (limited to 'arch/x86_64/kernel/pci-gart.c')
-rw-r--r--arch/x86_64/kernel/pci-gart.c980
1 files changed, 980 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/pci-gart.c b/arch/x86_64/kernel/pci-gart.c
new file mode 100644
index 000000000000..57f35c68aa34
--- /dev/null
+++ b/arch/x86_64/kernel/pci-gart.c
@@ -0,0 +1,980 @@
+/*
+ * Dynamic DMA mapping support for AMD Hammer.
+ *
+ * Use the integrated AGP GART in the Hammer northbridge as an IOMMU for PCI.
+ * This allows to use PCI devices that only support 32bit addresses on systems
+ * with more than 4GB.
+ *
+ * See Documentation/DMA-mapping.txt for the interface specification.
+ *
+ * Copyright 2002 Andi Kleen, SuSE Labs.
+ */
+
+#include <linux/config.h>
+#include <linux/types.h>
+#include <linux/ctype.h>
+#include <linux/agp_backend.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/string.h>
+#include <linux/spinlock.h>
+#include <linux/pci.h>
+#include <linux/module.h>
+#include <linux/topology.h>
+#include <linux/interrupt.h>
+#include <linux/bitops.h>
+#include <asm/atomic.h>
+#include <asm/io.h>
+#include <asm/mtrr.h>
+#include <asm/pgtable.h>
+#include <asm/proto.h>
+#include <asm/cacheflush.h>
+#include <asm/kdebug.h>
+
+dma_addr_t bad_dma_address;
+
+unsigned long iommu_bus_base; /* GART remapping area (physical) */
+static unsigned long iommu_size; /* size of remapping area bytes */
+static unsigned long iommu_pages; /* .. and in pages */
+
+u32 *iommu_gatt_base; /* Remapping table */
+
+int no_iommu;
+static int no_agp;
+#ifdef CONFIG_IOMMU_DEBUG
+int panic_on_overflow = 1;
+int force_iommu = 1;
+#else
+int panic_on_overflow = 0;
+int force_iommu = 0;
+#endif
+int iommu_merge = 1;
+int iommu_sac_force = 0;
+
+/* If this is disabled the IOMMU will use an optimized flushing strategy
+ of only flushing when an mapping is reused. With it true the GART is flushed
+ for every mapping. Problem is that doing the lazy flush seems to trigger
+ bugs with some popular PCI cards, in particular 3ware (but has been also
+ also seen with Qlogic at least). */
+int iommu_fullflush = 1;
+
+/* This tells the BIO block layer to assume merging. Default to off
+ because we cannot guarantee merging later. */
+int iommu_bio_merge = 0;
+
+#define MAX_NB 8
+
+/* Allocation bitmap for the remapping area */
+static DEFINE_SPINLOCK(iommu_bitmap_lock);
+static unsigned long *iommu_gart_bitmap; /* guarded by iommu_bitmap_lock */
+
+static u32 gart_unmapped_entry;
+
+#define GPTE_VALID 1
+#define GPTE_COHERENT 2
+#define GPTE_ENCODE(x) \
+ (((x) & 0xfffff000) | (((x) >> 32) << 4) | GPTE_VALID | GPTE_COHERENT)
+#define GPTE_DECODE(x) (((x) & 0xfffff000) | (((u64)(x) & 0xff0) << 28))
+
+#define to_pages(addr,size) \
+ (round_up(((addr) & ~PAGE_MASK) + (size), PAGE_SIZE) >> PAGE_SHIFT)
+
+#define for_all_nb(dev) \
+ dev = NULL; \
+ while ((dev = pci_get_device(PCI_VENDOR_ID_AMD, 0x1103, dev))!=NULL)\
+ if (dev->bus->number == 0 && \
+ (PCI_SLOT(dev->devfn) >= 24) && (PCI_SLOT(dev->devfn) <= 31))
+
+static struct pci_dev *northbridges[MAX_NB];
+static u32 northbridge_flush_word[MAX_NB];
+
+#define EMERGENCY_PAGES 32 /* = 128KB */
+
+#ifdef CONFIG_AGP
+#define AGPEXTERN extern
+#else
+#define AGPEXTERN
+#endif
+
+/* backdoor interface to AGP driver */
+AGPEXTERN int agp_memory_reserved;
+AGPEXTERN __u32 *agp_gatt_table;
+
+static unsigned long next_bit; /* protected by iommu_bitmap_lock */
+static int need_flush; /* global flush state. set for each gart wrap */
+static dma_addr_t dma_map_area(struct device *dev, unsigned long phys_mem,
+ size_t size, int dir, int do_panic);
+
+/* 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. */
+static struct device fallback_dev = {
+ .bus_id = "fallback device",
+ .coherent_dma_mask = 0xffffffff,
+ .dma_mask = &fallback_dev.coherent_dma_mask,
+};
+
+static unsigned long alloc_iommu(int size)
+{
+ unsigned long offset, flags;
+
+ spin_lock_irqsave(&iommu_bitmap_lock, flags);
+ offset = find_next_zero_string(iommu_gart_bitmap,next_bit,iommu_pages,size);
+ if (offset == -1) {
+ need_flush = 1;
+ offset = find_next_zero_string(iommu_gart_bitmap,0,next_bit,size);
+ }
+ if (offset != -1) {
+ set_bit_string(iommu_gart_bitmap, offset, size);
+ next_bit = offset+size;
+ if (next_bit >= iommu_pages) {
+ next_bit = 0;
+ need_flush = 1;
+ }
+ }
+ if (iommu_fullflush)
+ need_flush = 1;
+ spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
+ return offset;
+}
+
+static void free_iommu(unsigned long offset, int size)
+{
+ unsigned long flags;
+ if (size == 1) {
+ clear_bit(offset, iommu_gart_bitmap);
+ return;
+ }
+ spin_lock_irqsave(&iommu_bitmap_lock, flags);
+ __clear_bit_string(iommu_gart_bitmap, offset, size);
+ spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
+}
+
+/*
+ * Use global flush state to avoid races with multiple flushers.
+ */
+static void flush_gart(struct device *dev)
+{
+ unsigned long flags;
+ int flushed = 0;
+ int i, max;
+
+ spin_lock_irqsave(&iommu_bitmap_lock, flags);
+ if (need_flush) {
+ max = 0;
+ for (i = 0; i < MAX_NB; i++) {
+ if (!northbridges[i])
+ continue;
+ pci_write_config_dword(northbridges[i], 0x9c,
+ northbridge_flush_word[i] | 1);
+ flushed++;
+ max = i;
+ }
+ for (i = 0; i <= max; i++) {
+ u32 w;
+ if (!northbridges[i])
+ continue;
+ /* Make sure the hardware actually executed the flush. */
+ do {
+ pci_read_config_dword(northbridges[i], 0x9c, &w);
+ } while (w & 1);
+ }
+ if (!flushed)
+ printk("nothing to flush?\n");
+ need_flush = 0;
+ }
+ spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
+}
+
+/* Allocate DMA memory on node near device */
+noinline
+static void *dma_alloc_pages(struct device *dev, unsigned gfp, unsigned order)
+{
+ struct page *page;
+ int node;
+ if (dev->bus == &pci_bus_type) {
+ cpumask_t mask;
+ mask = pcibus_to_cpumask(to_pci_dev(dev)->bus);
+ node = cpu_to_node(first_cpu(mask));
+ } else
+ node = numa_node_id();
+ 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,
+ unsigned 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 = 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;
+
+ 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;
+ if (no_iommu || dma_mask < 0xffffffffUL) {
+ if (high) {
+ free_pages((unsigned long)memory,
+ get_order(size));
+
+ if (swiotlb) {
+ return
+ swiotlb_alloc_coherent(dev, size,
+ dma_handle,
+ gfp);
+ }
+
+ if (!(gfp & GFP_DMA)) {
+ gfp |= GFP_DMA;
+ goto again;
+ }
+ return NULL;
+ }
+ mmu = 0;
+ }
+ memset(memory, 0, size);
+ if (!mmu) {
+ *dma_handle = virt_to_bus(memory);
+ return memory;
+ }
+ }
+
+ *dma_handle = dma_map_area(dev, bus, size, PCI_DMA_BIDIRECTIONAL, 0);
+ if (*dma_handle == bad_dma_address)
+ goto error;
+ flush_gart(dev);
+ return memory;
+
+error:
+ 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;
+}
+
+/*
+ * 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 (swiotlb) {
+ swiotlb_free_coherent(dev, size, vaddr, bus);
+ return;
+ }
+
+ dma_unmap_single(dev, bus, size, 0);
+ free_pages((unsigned long)vaddr, get_order(size));
+}
+
+#ifdef CONFIG_IOMMU_LEAK
+
+#define SET_LEAK(x) if (iommu_leak_tab) \
+ iommu_leak_tab[x] = __builtin_return_address(0);
+#define CLEAR_LEAK(x) if (iommu_leak_tab) \
+ iommu_leak_tab[x] = NULL;
+
+/* Debugging aid for drivers that don't free their IOMMU tables */
+static void **iommu_leak_tab;
+static int leak_trace;
+int iommu_leak_pages = 20;
+void dump_leak(void)
+{
+ int i;
+ static int dump;
+ if (dump || !iommu_leak_tab) return;
+ dump = 1;
+ show_stack(NULL,NULL);
+ /* Very crude. dump some from the end of the table too */
+ printk("Dumping %d pages from end of IOMMU:\n", iommu_leak_pages);
+ for (i = 0; i < iommu_leak_pages; i+=2) {
+ printk("%lu: ", iommu_pages-i);
+ printk_address((unsigned long) iommu_leak_tab[iommu_pages-i]);
+ printk("%c", (i+1)%2 == 0 ? '\n' : ' ');
+ }
+ printk("\n");
+}
+#else
+#define SET_LEAK(x)
+#define CLEAR_LEAK(x)
+#endif
+
+static void iommu_full(struct device *dev, size_t size, int dir, int do_panic)
+{
+ /*
+ * Ran out of IOMMU space for this operation. This is very bad.
+ * Unfortunately the drivers cannot handle this operation properly.
+ * Return some non mapped prereserved space in the aperture and
+ * let the Northbridge deal with it. This will result in garbage
+ * in the IO operation. When the size exceeds the prereserved space
+ * memory corruption will occur or random memory will be DMAed
+ * out. Hopefully no network devices use single mappings that big.
+ */
+
+ printk(KERN_ERR
+ "PCI-DMA: Out of IOMMU space for %lu bytes at device %s\n",
+ size, dev->bus_id);
+
+ if (size > PAGE_SIZE*EMERGENCY_PAGES && do_panic) {
+ if (dir == PCI_DMA_FROMDEVICE || dir == PCI_DMA_BIDIRECTIONAL)
+ panic("PCI-DMA: Memory would be corrupted\n");
+ if (dir == PCI_DMA_TODEVICE || dir == PCI_DMA_BIDIRECTIONAL)
+ panic("PCI-DMA: Random memory would be DMAed\n");
+ }
+
+#ifdef CONFIG_IOMMU_LEAK
+ dump_leak();
+#endif
+}
+
+static inline int need_iommu(struct device *dev, unsigned long addr, size_t size)
+{
+ u64 mask = *dev->dma_mask;
+ int high = addr + size >= mask;
+ int mmu = high;
+ if (force_iommu)
+ mmu = 1;
+ if (no_iommu) {
+ if (high)
+ panic("PCI-DMA: high address but no IOMMU.\n");
+ mmu = 0;
+ }
+ return mmu;
+}
+
+static inline int nonforced_iommu(struct device *dev, unsigned long addr, size_t size)
+{
+ u64 mask = *dev->dma_mask;
+ int high = addr + size >= mask;
+ int mmu = high;
+ if (no_iommu) {
+ if (high)
+ panic("PCI-DMA: high address but no IOMMU.\n");
+ mmu = 0;
+ }
+ return mmu;
+}
+
+/* Map a single continuous physical area into the IOMMU.
+ * Caller needs to check if the iommu is needed and flush.
+ */
+static dma_addr_t dma_map_area(struct device *dev, unsigned long phys_mem,
+ size_t size, int dir, int do_panic)
+{
+ unsigned long npages = to_pages(phys_mem, size);
+ unsigned long iommu_page = alloc_iommu(npages);
+ int i;
+ if (iommu_page == -1) {
+ if (!nonforced_iommu(dev, phys_mem, size))
+ return phys_mem;
+ if (panic_on_overflow)
+ panic("dma_map_area overflow %lu bytes\n", size);
+ iommu_full(dev, size, dir, do_panic);
+ return bad_dma_address;
+ }
+
+ for (i = 0; i < npages; i++) {
+ iommu_gatt_base[iommu_page + i] = GPTE_ENCODE(phys_mem);
+ SET_LEAK(iommu_page + i);
+ phys_mem += PAGE_SIZE;
+ }
+ return iommu_bus_base + iommu_page*PAGE_SIZE + (phys_mem & ~PAGE_MASK);
+}
+
+/* Map a single area into the IOMMU */
+dma_addr_t dma_map_single(struct device *dev, void *addr, size_t size, int dir)
+{
+ unsigned long phys_mem, bus;
+
+ BUG_ON(dir == DMA_NONE);
+
+ if (swiotlb)
+ return swiotlb_map_single(dev,addr,size,dir);
+ if (!dev)
+ dev = &fallback_dev;
+
+ phys_mem = virt_to_phys(addr);
+ if (!need_iommu(dev, phys_mem, size))
+ return phys_mem;
+
+ bus = dma_map_area(dev, phys_mem, size, dir, 1);
+ flush_gart(dev);
+ return bus;
+}
+
+/* Fallback for dma_map_sg in case of overflow */
+static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,
+ int nents, int dir)
+{
+ int i;
+
+#ifdef CONFIG_IOMMU_DEBUG
+ printk(KERN_DEBUG "dma_map_sg overflow\n");
+#endif
+
+ for (i = 0; i < nents; i++ ) {
+ struct scatterlist *s = &sg[i];
+ unsigned long addr = page_to_phys(s->page) + s->offset;
+ if (nonforced_iommu(dev, addr, s->length)) {
+ addr = dma_map_area(dev, addr, s->length, dir, 0);
+ if (addr == bad_dma_address) {
+ if (i > 0)
+ dma_unmap_sg(dev, sg, i, dir);
+ nents = 0;
+ sg[0].dma_length = 0;
+ break;
+ }
+ }
+ s->dma_address = addr;
+ s->dma_length = s->length;
+ }
+ flush_gart(dev);
+ return nents;
+}
+
+/* Map multiple scatterlist entries continuous into the first. */
+static int __dma_map_cont(struct scatterlist *sg, int start, int stopat,
+ struct scatterlist *sout, unsigned long pages)
+{
+ unsigned long iommu_start = alloc_iommu(pages);
+ unsigned long iommu_page = iommu_start;
+ int i;
+
+ if (iommu_start == -1)
+ return -1;
+
+ for (i = start; i < stopat; i++) {
+ struct scatterlist *s = &sg[i];
+ unsigned long pages, addr;
+ unsigned long phys_addr = s->dma_address;
+
+ BUG_ON(i > start && s->offset);
+ if (i == start) {
+ *sout = *s;
+ sout->dma_address = iommu_bus_base;
+ sout->dma_address += iommu_page*PAGE_SIZE + s->offset;
+ sout->dma_length = s->length;
+ } else {
+ sout->dma_length += s->length;
+ }
+
+ addr = phys_addr;
+ pages = to_pages(s->offset, s->length);
+ while (pages--) {
+ iommu_gatt_base[iommu_page] = GPTE_ENCODE(addr);
+ SET_LEAK(iommu_page);
+ addr += PAGE_SIZE;
+ iommu_page++;
+ }
+ }
+ BUG_ON(iommu_page - iommu_start != pages);
+ return 0;
+}
+
+static inline int dma_map_cont(struct scatterlist *sg, int start, int stopat,
+ struct scatterlist *sout,
+ unsigned long pages, int need)
+{
+ if (!need) {
+ BUG_ON(stopat - start != 1);
+ *sout = sg[start];
+ sout->dma_length = sg[start].length;
+ return 0;
+ }
+ return __dma_map_cont(sg, start, stopat, sout, pages);
+}
+
+/*
+ * DMA map all entries in a scatterlist.
+ * Merge chunks that have page aligned sizes into a continuous mapping.
+ */
+int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)
+{
+ int i;
+ int out;
+ int start;
+ unsigned long pages = 0;
+ int need = 0, nextneed;
+
+ BUG_ON(dir == DMA_NONE);
+ if (nents == 0)
+ return 0;
+
+ if (swiotlb)
+ return swiotlb_map_sg(dev,sg,nents,dir);
+ if (!dev)
+ dev = &fallback_dev;
+
+ out = 0;
+ start = 0;
+ for (i = 0; i < nents; i++) {
+ struct scatterlist *s = &sg[i];
+ dma_addr_t addr = page_to_phys(s->page) + s->offset;
+ s->dma_address = addr;
+ BUG_ON(s->length == 0);
+
+ nextneed = need_iommu(dev, addr, s->length);
+
+ /* Handle the previous not yet processed entries */
+ if (i > start) {
+ struct scatterlist *ps = &sg[i-1];
+ /* Can only merge when the last chunk ends on a page
+ boundary and the new one doesn't have an offset. */
+ if (!iommu_merge || !nextneed || !need || s->offset ||
+ (ps->offset + ps->length) % PAGE_SIZE) {
+ if (dma_map_cont(sg, start, i, sg+out, pages,
+ need) < 0)
+ goto error;
+ out++;
+ pages = 0;
+ start = i;
+ }
+ }
+
+ need = nextneed;
+ pages += to_pages(s->offset, s->length);
+ }
+ if (dma_map_cont(sg, start, i, sg+out, pages, need) < 0)
+ goto error;
+ out++;
+ flush_gart(dev);
+ if (out < nents)
+ sg[out].dma_length = 0;
+ return out;
+
+error:
+ flush_gart(NULL);
+ dma_unmap_sg(dev, sg, nents, dir);
+ /* When it was forced try again unforced */
+ if (force_iommu)
+ return dma_map_sg_nonforce(dev, sg, nents, dir);
+ if (panic_on_overflow)
+ panic("dma_map_sg: overflow on %lu pages\n", pages);
+ iommu_full(dev, pages << PAGE_SHIFT, dir, 0);
+ for (i = 0; i < nents; i++)
+ sg[i].dma_address = bad_dma_address;
+ return 0;
+}
+
+/*
+ * Free a DMA mapping.
+ */
+void dma_unmap_single(struct device *dev, dma_addr_t dma_addr,
+ size_t size, int direction)
+{
+ unsigned long iommu_page;
+ int npages;
+ int i;
+
+ if (swiotlb) {
+ swiotlb_unmap_single(dev,dma_addr,size,direction);
+ return;
+ }
+
+ if (dma_addr < iommu_bus_base + EMERGENCY_PAGES*PAGE_SIZE ||
+ dma_addr >= iommu_bus_base + iommu_size)
+ return;
+ iommu_page = (dma_addr - iommu_bus_base)>>PAGE_SHIFT;
+ npages = to_pages(dma_addr, size);
+ for (i = 0; i < npages; i++) {
+ iommu_gatt_base[iommu_page + i] = gart_unmapped_entry;
+ CLEAR_LEAK(iommu_page + i);
+ }
+ free_iommu(iommu_page, npages);
+}
+
+/*
+ * Wrapper for pci_unmap_single working with scatterlists.
+ */
+void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, int dir)
+{
+ int i;
+ if (swiotlb) {
+ swiotlb_unmap_sg(dev,sg,nents,dir);
+ return;
+ }
+ for (i = 0; i < nents; i++) {
+ struct scatterlist *s = &sg[i];
+ if (!s->dma_length || !s->length)
+ break;
+ dma_unmap_single(dev, s->dma_address, s->dma_length, dir);
+ }
+}
+
+int dma_supported(struct device *dev, u64 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;
+}
+
+int dma_get_cache_alignment(void)
+{
+ return boot_cpu_data.x86_clflush_size;
+}
+
+EXPORT_SYMBOL(dma_unmap_sg);
+EXPORT_SYMBOL(dma_map_sg);
+EXPORT_SYMBOL(dma_map_single);
+EXPORT_SYMBOL(dma_unmap_single);
+EXPORT_SYMBOL(dma_supported);
+EXPORT_SYMBOL(no_iommu);
+EXPORT_SYMBOL(force_iommu);
+EXPORT_SYMBOL(bad_dma_address);
+EXPORT_SYMBOL(iommu_bio_merge);
+EXPORT_SYMBOL(iommu_sac_force);
+EXPORT_SYMBOL(dma_get_cache_alignment);
+EXPORT_SYMBOL(dma_alloc_coherent);
+EXPORT_SYMBOL(dma_free_coherent);
+
+static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size)
+{
+ unsigned long a;
+ if (!iommu_size) {
+ iommu_size = aper_size;
+ if (!no_agp)
+ iommu_size /= 2;
+ }
+
+ a = aper + iommu_size;
+ iommu_size -= round_up(a, LARGE_PAGE_SIZE) - a;
+
+ if (iommu_size < 64*1024*1024)
+ printk(KERN_WARNING
+ "PCI-DMA: Warning: Small IOMMU %luMB. Consider increasing the AGP aperture in BIOS\n",iommu_size>>20);
+
+ return iommu_size;
+}
+
+static __init unsigned read_aperture(struct pci_dev *dev, u32 *size)
+{
+ unsigned aper_size = 0, aper_base_32;
+ u64 aper_base;
+ unsigned aper_order;
+
+ pci_read_config_dword(dev, 0x94, &aper_base_32);
+ pci_read_config_dword(dev, 0x90, &aper_order);
+ aper_order = (aper_order >> 1) & 7;
+
+ aper_base = aper_base_32 & 0x7fff;
+ aper_base <<= 25;
+
+ aper_size = (32 * 1024 * 1024) << aper_order;
+ if (aper_base + aper_size >= 0xffffffff || !aper_size)
+ aper_base = 0;
+
+ *size = aper_size;
+ return aper_base;
+}
+
+/*
+ * Private Northbridge GATT initialization in case we cannot use the
+ * AGP driver for some reason.
+ */
+static __init int init_k8_gatt(struct agp_kern_info *info)
+{
+ struct pci_dev *dev;
+ void *gatt;
+ unsigned aper_base, new_aper_base;
+ unsigned aper_size, gatt_size, new_aper_size;
+
+ printk(KERN_INFO "PCI-DMA: Disabling AGP.\n");
+ aper_size = aper_base = info->aper_size = 0;
+ for_all_nb(dev) {
+ new_aper_base = read_aperture(dev, &new_aper_size);
+ if (!new_aper_base)
+ goto nommu;
+
+ if (!aper_base) {
+ aper_size = new_aper_size;
+ aper_base = new_aper_base;
+ }
+ if (aper_size != new_aper_size || aper_base != new_aper_base)
+ goto nommu;
+ }
+ if (!aper_base)
+ goto nommu;
+ info->aper_base = aper_base;
+ info->aper_size = aper_size>>20;
+
+ gatt_size = (aper_size >> PAGE_SHIFT) * sizeof(u32);
+ gatt = (void *)__get_free_pages(GFP_KERNEL, get_order(gatt_size));
+ if (!gatt)
+ panic("Cannot allocate GATT table");
+ memset(gatt, 0, gatt_size);
+ agp_gatt_table = gatt;
+
+ for_all_nb(dev) {
+ u32 ctl;
+ u32 gatt_reg;
+
+ gatt_reg = __pa(gatt) >> 12;
+ gatt_reg <<= 4;
+ pci_write_config_dword(dev, 0x98, gatt_reg);
+ pci_read_config_dword(dev, 0x90, &ctl);
+
+ ctl |= 1;
+ ctl &= ~((1<<4) | (1<<5));
+
+ pci_write_config_dword(dev, 0x90, ctl);
+ }
+ flush_gart(NULL);
+
+ printk("PCI-DMA: aperture base @ %x size %u KB\n",aper_base, aper_size>>10);
+ return 0;
+
+ nommu:
+ /* Should not happen anymore */
+ printk(KERN_ERR "PCI-DMA: More than 4GB of RAM and no IOMMU\n"
+ KERN_ERR "PCI-DMA: 32bit PCI IO may malfunction.");
+ return -1;
+}
+
+extern int agp_amd64_init(void);
+
+static int __init pci_iommu_init(void)
+{
+ struct agp_kern_info info;
+ unsigned long aper_size;
+ unsigned long iommu_start;
+ struct pci_dev *dev;
+ unsigned long scratch;
+ long i;
+
+#ifndef CONFIG_AGP_AMD64
+ no_agp = 1;
+#else
+ /* Makefile puts PCI initialization via subsys_initcall first. */
+ /* Add other K8 AGP bridge drivers here */
+ no_agp = no_agp ||
+ (agp_amd64_init() < 0) ||
+ (agp_copy_info(agp_bridge, &info) < 0);
+#endif
+
+ if (swiotlb) {
+ no_iommu = 1;
+ printk(KERN_INFO "PCI-DMA: Using software bounce buffering for IO (SWIOTLB)\n");
+ return -1;
+ }
+
+ if (no_iommu ||
+ (!force_iommu && end_pfn < 0xffffffff>>PAGE_SHIFT) ||
+ !iommu_aperture ||
+ (no_agp && init_k8_gatt(&info) < 0)) {
+ printk(KERN_INFO "PCI-DMA: Disabling IOMMU.\n");
+ no_iommu = 1;
+ return -1;
+ }
+
+ aper_size = info.aper_size * 1024 * 1024;
+ iommu_size = check_iommu_size(info.aper_base, aper_size);
+ iommu_pages = iommu_size >> PAGE_SHIFT;
+
+ iommu_gart_bitmap = (void*)__get_free_pages(GFP_KERNEL,
+ get_order(iommu_pages/8));
+ if (!iommu_gart_bitmap)
+ panic("Cannot allocate iommu bitmap\n");
+ memset(iommu_gart_bitmap, 0, iommu_pages/8);
+
+#ifdef CONFIG_IOMMU_LEAK
+ if (leak_trace) {
+ iommu_leak_tab = (void *)__get_free_pages(GFP_KERNEL,
+ get_order(iommu_pages*sizeof(void *)));
+ if (iommu_leak_tab)
+ memset(iommu_leak_tab, 0, iommu_pages * 8);
+ else
+ printk("PCI-DMA: Cannot allocate leak trace area\n");
+ }
+#endif
+
+ /*
+ * Out of IOMMU space handling.
+ * Reserve some invalid pages at the beginning of the GART.
+ */
+ set_bit_string(iommu_gart_bitmap, 0, EMERGENCY_PAGES);
+
+ agp_memory_reserved = iommu_size;
+ printk(KERN_INFO
+ "PCI-DMA: Reserving %luMB of IOMMU area in the AGP aperture\n",
+ iommu_size>>20);
+
+ iommu_start = aper_size - iommu_size;
+ iommu_bus_base = info.aper_base + iommu_start;
+ bad_dma_address = iommu_bus_base;
+ iommu_gatt_base = agp_gatt_table + (iommu_start>>PAGE_SHIFT);
+
+ /*
+ * Unmap the IOMMU part of the GART. The alias of the page is
+ * always mapped with cache enabled and there is no full cache
+ * coherency across the GART remapping. The unmapping avoids
+ * automatic prefetches from the CPU allocating cache lines in
+ * there. All CPU accesses are done via the direct mapping to
+ * the backing memory. The GART address is only used by PCI
+ * devices.
+ */
+ clear_kernel_mapping((unsigned long)__va(iommu_bus_base), iommu_size);
+
+ /*
+ * Try to workaround a bug (thanks to BenH)
+ * Set unmapped entries to a scratch page instead of 0.
+ * Any prefetches that hit unmapped entries won't get an bus abort
+ * then.
+ */
+ scratch = get_zeroed_page(GFP_KERNEL);
+ if (!scratch)
+ panic("Cannot allocate iommu scratch page");
+ gart_unmapped_entry = GPTE_ENCODE(__pa(scratch));
+ for (i = EMERGENCY_PAGES; i < iommu_pages; i++)
+ iommu_gatt_base[i] = gart_unmapped_entry;
+
+ for_all_nb(dev) {
+ u32 flag;
+ int cpu = PCI_SLOT(dev->devfn) - 24;
+ if (cpu >= MAX_NB)
+ continue;
+ northbridges[cpu] = dev;
+ pci_read_config_dword(dev, 0x9c, &flag); /* cache flush word */
+ northbridge_flush_word[cpu] = flag;
+ }
+
+ flush_gart(NULL);
+
+ return 0;
+}
+
+/* Must execute after PCI subsystem */
+fs_initcall(pci_iommu_init);
+
+/* 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)
+{
+ int arg;
+
+ while (*p) {
+ if (!strncmp(p,"noagp",5))
+ no_agp = 1;
+ if (!strncmp(p,"off",3))
+ no_iommu = 1;
+ if (!strncmp(p,"force",5)) {
+ force_iommu = 1;
+ iommu_aperture_allowed = 1;
+ }
+ if (!strncmp(p,"allowed",7))
+ iommu_aperture_allowed = 1;
+ if (!strncmp(p,"noforce",7)) {
+ iommu_merge = 0;
+ force_iommu = 0;
+ }
+ if (!strncmp(p, "memaper", 7)) {
+ fallback_aper_force = 1;
+ p += 7;
+ if (*p == '=') {
+ ++p;
+ if (get_option(&p, &arg))
+ fallback_aper_order = arg;
+ }
+ }
+ 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, "fullflush",8))
+ iommu_fullflush = 1;
+ if (!strncmp(p, "nofullflush",11))
+ iommu_fullflush = 0;
+ if (!strncmp(p, "soft",4))
+ swiotlb = 1;
+ if (!strncmp(p, "noaperture",10))
+ fix_aperture = 0;
+#ifdef CONFIG_IOMMU_LEAK
+ if (!strncmp(p,"leak",4)) {
+ leak_trace = 1;
+ p += 4;
+ if (*p == '=') ++p;
+ if (isdigit(*p) && get_option(&p, &arg))
+ iommu_leak_pages = arg;
+ } else
+#endif
+ if (isdigit(*p) && get_option(&p, &arg))
+ iommu_size = arg;
+ p += strcspn(p, ",");
+ if (*p == ',')
+ ++p;
+ }
+ return 1;
+}
generated by cgit (git 2.34.1) at 2024-06-20 23:26:26 +0000