From 250c22777fe1ccd7ac588579a6c16db4c0161cc5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 11 Oct 2007 11:17:24 +0200 Subject: x86_64: move kernel Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar --- arch/x86/kernel/pci-gart_64.c | 740 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 740 insertions(+) create mode 100644 arch/x86/kernel/pci-gart_64.c (limited to 'arch/x86/kernel/pci-gart_64.c') diff --git a/arch/x86/kernel/pci-gart_64.c b/arch/x86/kernel/pci-gart_64.c new file mode 100644 index 0000000..4918c57 --- /dev/null +++ b/arch/x86/kernel/pci-gart_64.c @@ -0,0 +1,740 @@ +/* + * 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 +#include +#include +#include + +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 */ + +/* 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; + +/* 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 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 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,iommu_pages,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; + 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(void) +{ + unsigned long flags; + spin_lock_irqsave(&iommu_bitmap_lock, flags); + if (need_flush) { + k8_flush_garts(); + need_flush = 0; + } + spin_unlock_irqrestore(&iommu_bitmap_lock, flags); +} + +#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) +{ + /* + * 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) { + 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(KERN_ERR "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; + 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; + 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, dma_addr_t phys_mem, + size_t size, int dir) +{ + 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); + 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); +} + +static dma_addr_t gart_map_simple(struct device *dev, char *buf, + size_t size, int dir) +{ + dma_addr_t map = dma_map_area(dev, virt_to_bus(buf), size, dir); + flush_gart(); + return map; +} + +/* Map a single area into the IOMMU */ +static dma_addr_t gart_map_single(struct device *dev, void *addr, size_t size, int dir) +{ + unsigned long phys_mem, bus; + + if (!dev) + dev = &fallback_dev; + + phys_mem = virt_to_phys(addr); + if (!need_iommu(dev, phys_mem, size)) + return phys_mem; + + bus = gart_map_simple(dev, addr, size, dir); + return bus; +} + +/* + * Free a DMA mapping. + */ +static void gart_unmap_single(struct device *dev, dma_addr_t dma_addr, + size_t size, int direction) +{ + unsigned long iommu_page; + int npages; + int i; + + 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. + */ +static void gart_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, int dir) +{ + int i; + + for (i = 0; i < nents; i++) { + struct scatterlist *s = &sg[i]; + if (!s->dma_length || !s->length) + break; + gart_unmap_single(dev, s->dma_address, s->dma_length, dir); + } +} + +/* 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); + if (addr == bad_dma_address) { + if (i > 0) + gart_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(); + 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 gart_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; + + if (nents == 0) + return 0; + + 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(); + if (out < nents) + sg[out].dma_length = 0; + return out; + +error: + flush_gart(); + gart_unmap_sg(dev, sg, nents, dir); + /* When it was forced or merged try again in a dumb way */ + if (force_iommu || iommu_merge) { + out = dma_map_sg_nonforce(dev, sg, nents, dir); + if (out > 0) + return out; + } + if (panic_on_overflow) + panic("dma_map_sg: overflow on %lu pages\n", pages); + iommu_full(dev, pages << PAGE_SHIFT, dir); + for (i = 0; i < nents; i++) + sg[i].dma_address = bad_dma_address; + return 0; +} + +static int no_agp; + +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 > 0x100000000UL || !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; + int i; + + printk(KERN_INFO "PCI-DMA: Disabling AGP.\n"); + aper_size = aper_base = info->aper_size = 0; + dev = NULL; + for (i = 0; i < num_k8_northbridges; i++) { + dev = k8_northbridges[i]; + 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"); + if (change_page_attr_addr((unsigned long)gatt, gatt_size >> PAGE_SHIFT, PAGE_KERNEL_NOCACHE)) + panic("Could not set GART PTEs to uncacheable pages"); + global_flush_tlb(); + + memset(gatt, 0, gatt_size); + agp_gatt_table = gatt; + + for (i = 0; i < num_k8_northbridges; i++) { + u32 ctl; + u32 gatt_reg; + + dev = k8_northbridges[i]; + 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(); + + 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.\n"); + return -1; +} + +extern int agp_amd64_init(void); + +static const struct dma_mapping_ops gart_dma_ops = { + .mapping_error = NULL, + .map_single = gart_map_single, + .map_simple = gart_map_simple, + .unmap_single = gart_unmap_single, + .sync_single_for_cpu = NULL, + .sync_single_for_device = NULL, + .sync_single_range_for_cpu = NULL, + .sync_single_range_for_device = NULL, + .sync_sg_for_cpu = NULL, + .sync_sg_for_device = NULL, + .map_sg = gart_map_sg, + .unmap_sg = gart_unmap_sg, +}; + +void gart_iommu_shutdown(void) +{ + struct pci_dev *dev; + int i; + + if (no_agp && (dma_ops != &gart_dma_ops)) + return; + + for (i = 0; i < num_k8_northbridges; i++) { + u32 ctl; + + dev = k8_northbridges[i]; + pci_read_config_dword(dev, 0x90, &ctl); + + ctl &= ~1; + + pci_write_config_dword(dev, 0x90, ctl); + } +} + +void __init gart_iommu_init(void) +{ + struct agp_kern_info info; + unsigned long aper_size; + unsigned long iommu_start; + unsigned long scratch; + long i; + + if (cache_k8_northbridges() < 0 || num_k8_northbridges == 0) { + printk(KERN_INFO "PCI-GART: No AMD northbridge found.\n"); + return; + } + +#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) + return; + + /* Did we detect a different HW IOMMU? */ + if (iommu_detected && !iommu_aperture) + return; + + if (no_iommu || + (!force_iommu && end_pfn <= MAX_DMA32_PFN) || + !iommu_aperture || + (no_agp && init_k8_gatt(&info) < 0)) { + if (end_pfn > MAX_DMA32_PFN) { + printk(KERN_ERR "WARNING more than 4GB of memory " + "but GART IOMMU not available.\n" + KERN_ERR "WARNING 32bit PCI may malfunction.\n"); + } + return; + } + + printk(KERN_INFO "PCI-DMA: using GART IOMMU.\n"); + 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; + + flush_gart(); + dma_ops = &gart_dma_ops; +} + +void __init gart_parse_options(char *p) +{ + int arg; + +#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; + } +#endif + if (isdigit(*p) && get_option(&p, &arg)) + iommu_size = arg; + if (!strncmp(p, "fullflush",8)) + iommu_fullflush = 1; + if (!strncmp(p, "nofullflush",11)) + iommu_fullflush = 0; + if (!strncmp(p,"noagp",5)) + no_agp = 1; + if (!strncmp(p, "noaperture",10)) + fix_aperture = 0; + /* duplicated from pci-dma.c */ + if (!strncmp(p,"force",5)) + iommu_aperture_allowed = 1; + if (!strncmp(p,"allowed",7)) + iommu_aperture_allowed = 1; + if (!strncmp(p, "memaper", 7)) { + fallback_aper_force = 1; + p += 7; + if (*p == '=') { + ++p; + if (get_option(&p, &arg)) + fallback_aper_order = arg; + } + } +} -- cgit v1.1