From 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 16 Apr 2005 15:20:36 -0700 Subject: Linux-2.6.12-rc2 Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip! --- arch/x86_64/kernel/pci-gart.c | 980 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 980 insertions(+) create mode 100644 arch/x86_64/kernel/pci-gart.c (limited to 'arch/x86_64/kernel/pci-gart.c') 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +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; +} -- cgit v1.2.1