diff options
Diffstat (limited to 'arch/x86/kernel/amd_iommu.c')
| -rw-r--r-- | arch/x86/kernel/amd_iommu.c | 1383 |
1 files changed, 1383 insertions, 0 deletions
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c new file mode 100644 index 00000000000..34e4d112b1e --- /dev/null +++ b/arch/x86/kernel/amd_iommu.c @@ -0,0 +1,1383 @@ +/* + * Copyright (C) 2007-2008 Advanced Micro Devices, Inc. + * Author: Joerg Roedel <joerg.roedel@amd.com> + * Leo Duran <leo.duran@amd.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <linux/pci.h> +#include <linux/gfp.h> +#include <linux/bitops.h> +#include <linux/scatterlist.h> +#include <linux/iommu-helper.h> +#include <asm/proto.h> +#include <asm/iommu.h> +#include <asm/amd_iommu_types.h> +#include <asm/amd_iommu.h> + +#define CMD_SET_TYPE(cmd, t) ((cmd)->data[1] |= ((t) << 28)) + +#define EXIT_LOOP_COUNT 10000000 + +static DEFINE_RWLOCK(amd_iommu_devtable_lock); + +/* A list of preallocated protection domains */ +static LIST_HEAD(iommu_pd_list); +static DEFINE_SPINLOCK(iommu_pd_list_lock); + +/* + * general struct to manage commands send to an IOMMU + */ +struct iommu_cmd { + u32 data[4]; +}; + +static int dma_ops_unity_map(struct dma_ops_domain *dma_dom, + struct unity_map_entry *e); + +/* returns !0 if the IOMMU is caching non-present entries in its TLB */ +static int iommu_has_npcache(struct amd_iommu *iommu) +{ + return iommu->cap & IOMMU_CAP_NPCACHE; +} + +/**************************************************************************** + * + * Interrupt handling functions + * + ****************************************************************************/ + +static void iommu_print_event(void *__evt) +{ + u32 *event = __evt; + int type = (event[1] >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK; + int devid = (event[0] >> EVENT_DEVID_SHIFT) & EVENT_DEVID_MASK; + int domid = (event[1] >> EVENT_DOMID_SHIFT) & EVENT_DOMID_MASK; + int flags = (event[1] >> EVENT_FLAGS_SHIFT) & EVENT_FLAGS_MASK; + u64 address = (u64)(((u64)event[3]) << 32) | event[2]; + + printk(KERN_ERR "AMD IOMMU: Event logged ["); + + switch (type) { + case EVENT_TYPE_ILL_DEV: + printk("ILLEGAL_DEV_TABLE_ENTRY device=%02x:%02x.%x " + "address=0x%016llx flags=0x%04x]\n", + PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid), + address, flags); + break; + case EVENT_TYPE_IO_FAULT: + printk("IO_PAGE_FAULT device=%02x:%02x.%x " + "domain=0x%04x address=0x%016llx flags=0x%04x]\n", + PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid), + domid, address, flags); + break; + case EVENT_TYPE_DEV_TAB_ERR: + printk("DEV_TAB_HARDWARE_ERROR device=%02x:%02x.%x " + "address=0x%016llx flags=0x%04x]\n", + PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid), + address, flags); + break; + case EVENT_TYPE_PAGE_TAB_ERR: + printk("PAGE_TAB_HARDWARE_ERROR device=%02x:%02x.%x " + "domain=0x%04x address=0x%016llx flags=0x%04x]\n", + PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid), + domid, address, flags); + break; + case EVENT_TYPE_ILL_CMD: + printk("ILLEGAL_COMMAND_ERROR address=0x%016llx]\n", address); + break; + case EVENT_TYPE_CMD_HARD_ERR: + printk("COMMAND_HARDWARE_ERROR address=0x%016llx " + "flags=0x%04x]\n", address, flags); + break; + case EVENT_TYPE_IOTLB_INV_TO: + printk("IOTLB_INV_TIMEOUT device=%02x:%02x.%x " + "address=0x%016llx]\n", + PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid), + address); + break; + case EVENT_TYPE_INV_DEV_REQ: + printk("INVALID_DEVICE_REQUEST device=%02x:%02x.%x " + "address=0x%016llx flags=0x%04x]\n", + PCI_BUS(devid), PCI_SLOT(devid), PCI_FUNC(devid), + address, flags); + break; + default: + printk(KERN_ERR "UNKNOWN type=0x%02x]\n", type); + } +} + +static void iommu_poll_events(struct amd_iommu *iommu) +{ + u32 head, tail; + unsigned long flags; + + spin_lock_irqsave(&iommu->lock, flags); + + head = readl(iommu->mmio_base + MMIO_EVT_HEAD_OFFSET); + tail = readl(iommu->mmio_base + MMIO_EVT_TAIL_OFFSET); + + while (head != tail) { + iommu_print_event(iommu->evt_buf + head); + head = (head + EVENT_ENTRY_SIZE) % iommu->evt_buf_size; + } + + writel(head, iommu->mmio_base + MMIO_EVT_HEAD_OFFSET); + + spin_unlock_irqrestore(&iommu->lock, flags); +} + +irqreturn_t amd_iommu_int_handler(int irq, void *data) +{ + struct amd_iommu *iommu; + + list_for_each_entry(iommu, &amd_iommu_list, list) + iommu_poll_events(iommu); + + return IRQ_HANDLED; +} + +/**************************************************************************** + * + * IOMMU command queuing functions + * + ****************************************************************************/ + +/* + * Writes the command to the IOMMUs command buffer and informs the + * hardware about the new command. Must be called with iommu->lock held. + */ +static int __iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd) +{ + u32 tail, head; + u8 *target; + + tail = readl(iommu->mmio_base + MMIO_CMD_TAIL_OFFSET); + target = iommu->cmd_buf + tail; + memcpy_toio(target, cmd, sizeof(*cmd)); + tail = (tail + sizeof(*cmd)) % iommu->cmd_buf_size; + head = readl(iommu->mmio_base + MMIO_CMD_HEAD_OFFSET); + if (tail == head) + return -ENOMEM; + writel(tail, iommu->mmio_base + MMIO_CMD_TAIL_OFFSET); + + return 0; +} + +/* + * General queuing function for commands. Takes iommu->lock and calls + * __iommu_queue_command(). + */ +static int iommu_queue_command(struct amd_iommu *iommu, struct iommu_cmd *cmd) +{ + unsigned long flags; + int ret; + + spin_lock_irqsave(&iommu->lock, flags); + ret = __iommu_queue_command(iommu, cmd); + spin_unlock_irqrestore(&iommu->lock, flags); + + return ret; +} + +/* + * This function is called whenever we need to ensure that the IOMMU has + * completed execution of all commands we sent. It sends a + * COMPLETION_WAIT command and waits for it to finish. The IOMMU informs + * us about that by writing a value to a physical address we pass with + * the command. + */ +static int iommu_completion_wait(struct amd_iommu *iommu) +{ + int ret = 0, ready = 0; + unsigned status = 0; + struct iommu_cmd cmd; + unsigned long flags, i = 0; + + memset(&cmd, 0, sizeof(cmd)); + cmd.data[0] = CMD_COMPL_WAIT_INT_MASK; + CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT); + + iommu->need_sync = 0; + + spin_lock_irqsave(&iommu->lock, flags); + + ret = __iommu_queue_command(iommu, &cmd); + + if (ret) + goto out; + + while (!ready && (i < EXIT_LOOP_COUNT)) { + ++i; + /* wait for the bit to become one */ + status = readl(iommu->mmio_base + MMIO_STATUS_OFFSET); + ready = status & MMIO_STATUS_COM_WAIT_INT_MASK; + } + + /* set bit back to zero */ + status &= ~MMIO_STATUS_COM_WAIT_INT_MASK; + writel(status, iommu->mmio_base + MMIO_STATUS_OFFSET); + + if (unlikely((i == EXIT_LOOP_COUNT) && printk_ratelimit())) + printk(KERN_WARNING "AMD IOMMU: Completion wait loop failed\n"); +out: + spin_unlock_irqrestore(&iommu->lock, flags); + + return 0; +} + +/* + * Command send function for invalidating a device table entry + */ +static int iommu_queue_inv_dev_entry(struct amd_iommu *iommu, u16 devid) +{ + struct iommu_cmd cmd; + int ret; + + BUG_ON(iommu == NULL); + + memset(&cmd, 0, sizeof(cmd)); + CMD_SET_TYPE(&cmd, CMD_INV_DEV_ENTRY); + cmd.data[0] = devid; + + ret = iommu_queue_command(iommu, &cmd); + + iommu->need_sync = 1; + + return ret; +} + +/* + * Generic command send function for invalidaing TLB entries + */ +static int iommu_queue_inv_iommu_pages(struct amd_iommu *iommu, + u64 address, u16 domid, int pde, int s) +{ + struct iommu_cmd cmd; + int ret; + + memset(&cmd, 0, sizeof(cmd)); + address &= PAGE_MASK; + CMD_SET_TYPE(&cmd, CMD_INV_IOMMU_PAGES); + cmd.data[1] |= domid; + cmd.data[2] = lower_32_bits(address); + cmd.data[3] = upper_32_bits(address); + if (s) /* size bit - we flush more than one 4kb page */ + cmd.data[2] |= CMD_INV_IOMMU_PAGES_SIZE_MASK; + if (pde) /* PDE bit - we wan't flush everything not only the PTEs */ + cmd.data[2] |= CMD_INV_IOMMU_PAGES_PDE_MASK; + + ret = iommu_queue_command(iommu, &cmd); + + iommu->need_sync = 1; + + return ret; +} + +/* + * TLB invalidation function which is called from the mapping functions. + * It invalidates a single PTE if the range to flush is within a single + * page. Otherwise it flushes the whole TLB of the IOMMU. + */ +static int iommu_flush_pages(struct amd_iommu *iommu, u16 domid, + u64 address, size_t size) +{ + int s = 0; + unsigned pages = iommu_num_pages(address, size); + + address &= PAGE_MASK; + + if (pages > 1) { + /* + * If we have to flush more than one page, flush all + * TLB entries for this domain + */ + address = CMD_INV_IOMMU_ALL_PAGES_ADDRESS; + s = 1; + } + + iommu_queue_inv_iommu_pages(iommu, address, domid, 0, s); + + return 0; +} + +/* Flush the whole IO/TLB for a given protection domain */ +static void iommu_flush_tlb(struct amd_iommu *iommu, u16 domid) +{ + u64 address = CMD_INV_IOMMU_ALL_PAGES_ADDRESS; + + iommu_queue_inv_iommu_pages(iommu, address, domid, 0, 1); +} + +/**************************************************************************** + * + * The functions below are used the create the page table mappings for + * unity mapped regions. + * + ****************************************************************************/ + +/* + * Generic mapping functions. It maps a physical address into a DMA + * address space. It allocates the page table pages if necessary. + * In the future it can be extended to a generic mapping function + * supporting all features of AMD IOMMU page tables like level skipping + * and full 64 bit address spaces. + */ +static int iommu_map(struct protection_domain *dom, + unsigned long bus_addr, + unsigned long phys_addr, + int prot) +{ + u64 __pte, *pte, *page; + + bus_addr = PAGE_ALIGN(bus_addr); + phys_addr = PAGE_ALIGN(bus_addr); + + /* only support 512GB address spaces for now */ + if (bus_addr > IOMMU_MAP_SIZE_L3 || !(prot & IOMMU_PROT_MASK)) + return -EINVAL; + + pte = &dom->pt_root[IOMMU_PTE_L2_INDEX(bus_addr)]; + + if (!IOMMU_PTE_PRESENT(*pte)) { + page = (u64 *)get_zeroed_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + *pte = IOMMU_L2_PDE(virt_to_phys(page)); + } + + pte = IOMMU_PTE_PAGE(*pte); + pte = &pte[IOMMU_PTE_L1_INDEX(bus_addr)]; + + if (!IOMMU_PTE_PRESENT(*pte)) { + page = (u64 *)get_zeroed_page(GFP_KERNEL); + if (!page) + return -ENOMEM; + *pte = IOMMU_L1_PDE(virt_to_phys(page)); + } + + pte = IOMMU_PTE_PAGE(*pte); + pte = &pte[IOMMU_PTE_L0_INDEX(bus_addr)]; + + if (IOMMU_PTE_PRESENT(*pte)) + return -EBUSY; + + __pte = phys_addr | IOMMU_PTE_P; + if (prot & IOMMU_PROT_IR) + __pte |= IOMMU_PTE_IR; + if (prot & IOMMU_PROT_IW) + __pte |= IOMMU_PTE_IW; + + *pte = __pte; + + return 0; +} + +/* + * This function checks if a specific unity mapping entry is needed for + * this specific IOMMU. + */ +static int iommu_for_unity_map(struct amd_iommu *iommu, + struct unity_map_entry *entry) +{ + u16 bdf, i; + + for (i = entry->devid_start; i <= entry->devid_end; ++i) { + bdf = amd_iommu_alias_table[i]; + if (amd_iommu_rlookup_table[bdf] == iommu) + return 1; + } + + return 0; +} + +/* + * Init the unity mappings for a specific IOMMU in the system + * + * Basically iterates over all unity mapping entries and applies them to + * the default domain DMA of that IOMMU if necessary. + */ +static int iommu_init_unity_mappings(struct amd_iommu *iommu) +{ + struct unity_map_entry *entry; + int ret; + + list_for_each_entry(entry, &amd_iommu_unity_map, list) { + if (!iommu_for_unity_map(iommu, entry)) + continue; + ret = dma_ops_unity_map(iommu->default_dom, entry); + if (ret) + return ret; + } + + return 0; +} + +/* + * This function actually applies the mapping to the page table of the + * dma_ops domain. + */ +static int dma_ops_unity_map(struct dma_ops_domain *dma_dom, + struct unity_map_entry *e) +{ + u64 addr; + int ret; + + for (addr = e->address_start; addr < e->address_end; + addr += PAGE_SIZE) { + ret = iommu_map(&dma_dom->domain, addr, addr, e->prot); + if (ret) + return ret; + /* + * if unity mapping is in aperture range mark the page + * as allocated in the aperture + */ + if (addr < dma_dom->aperture_size) + __set_bit(addr >> PAGE_SHIFT, dma_dom->bitmap); + } + + return 0; +} + +/* + * Inits the unity mappings required for a specific device + */ +static int init_unity_mappings_for_device(struct dma_ops_domain *dma_dom, + u16 devid) +{ + struct unity_map_entry *e; + int ret; + + list_for_each_entry(e, &amd_iommu_unity_map, list) { + if (!(devid >= e->devid_start && devid <= e->devid_end)) + continue; + ret = dma_ops_unity_map(dma_dom, e); + if (ret) + return ret; + } + + return 0; +} + +/**************************************************************************** + * + * The next functions belong to the address allocator for the dma_ops + * interface functions. They work like the allocators in the other IOMMU + * drivers. Its basically a bitmap which marks the allocated pages in + * the aperture. Maybe it could be enhanced in the future to a more + * efficient allocator. + * + ****************************************************************************/ + +/* + * The address allocator core function. + * + * called with domain->lock held + */ +static unsigned long dma_ops_alloc_addresses(struct device *dev, + struct dma_ops_domain *dom, + unsigned int pages, + unsigned long align_mask, + u64 dma_mask) +{ + unsigned long limit; + unsigned long address; + unsigned long boundary_size; + + boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1, + PAGE_SIZE) >> PAGE_SHIFT; + limit = iommu_device_max_index(dom->aperture_size >> PAGE_SHIFT, 0, + dma_mask >> PAGE_SHIFT); + + if (dom->next_bit >= limit) { + dom->next_bit = 0; + dom->need_flush = true; + } + + address = iommu_area_alloc(dom->bitmap, limit, dom->next_bit, pages, + 0 , boundary_size, align_mask); + if (address == -1) { + address = iommu_area_alloc(dom->bitmap, limit, 0, pages, + 0, boundary_size, align_mask); + dom->need_flush = true; + } + + if (likely(address != -1)) { + dom->next_bit = address + pages; + address <<= PAGE_SHIFT; + } else + address = bad_dma_address; + + WARN_ON((address + (PAGE_SIZE*pages)) > dom->aperture_size); + + return address; +} + +/* + * The address free function. + * + * called with domain->lock held + */ +static void dma_ops_free_addresses(struct dma_ops_domain *dom, + unsigned long address, + unsigned int pages) +{ + address >>= PAGE_SHIFT; + iommu_area_free(dom->bitmap, address, pages); +} + +/**************************************************************************** + * + * The next functions belong to the domain allocation. A domain is + * allocated for every IOMMU as the default domain. If device isolation + * is enabled, every device get its own domain. The most important thing + * about domains is the page table mapping the DMA address space they + * contain. + * + ****************************************************************************/ + +static u16 domain_id_alloc(void) +{ + unsigned long flags; + int id; + + write_lock_irqsave(&amd_iommu_devtable_lock, flags); + id = find_first_zero_bit(amd_iommu_pd_alloc_bitmap, MAX_DOMAIN_ID); + BUG_ON(id == 0); + if (id > 0 && id < MAX_DOMAIN_ID) + __set_bit(id, amd_iommu_pd_alloc_bitmap); + else + id = 0; + write_unlock_irqrestore(&amd_iommu_devtable_lock, flags); + + return id; +} + +/* + * Used to reserve address ranges in the aperture (e.g. for exclusion + * ranges. + */ +static void dma_ops_reserve_addresses(struct dma_ops_domain *dom, + unsigned long start_page, + unsigned int pages) +{ + unsigned int last_page = dom->aperture_size >> PAGE_SHIFT; + + if (start_page + pages > last_page) + pages = last_page - start_page; + + iommu_area_reserve(dom->bitmap, start_page, pages); +} + +static void dma_ops_free_pagetable(struct dma_ops_domain *dma_dom) +{ + int i, j; + u64 *p1, *p2, *p3; + + p1 = dma_dom->domain.pt_root; + + if (!p1) + return; + + for (i = 0; i < 512; ++i) { + if (!IOMMU_PTE_PRESENT(p1[i])) + continue; + + p2 = IOMMU_PTE_PAGE(p1[i]); + for (j = 0; j < 512; ++i) { + if (!IOMMU_PTE_PRESENT(p2[j])) + continue; + p3 = IOMMU_PTE_PAGE(p2[j]); + free_page((unsigned long)p3); + } + + free_page((unsigned long)p2); + } + + free_page((unsigned long)p1); +} + +/* + * Free a domain, only used if something went wrong in the + * allocation path and we need to free an already allocated page table + */ +static void dma_ops_domain_free(struct dma_ops_domain *dom) +{ + if (!dom) + return; + + dma_ops_free_pagetable(dom); + + kfree(dom->pte_pages); + + kfree(dom->bitmap); + + kfree(dom); +} + +/* + * Allocates a new protection domain usable for the dma_ops functions. + * It also intializes the page table and the address allocator data + * structures required for the dma_ops interface + */ +static struct dma_ops_domain *dma_ops_domain_alloc(struct amd_iommu *iommu, + unsigned order) +{ + struct dma_ops_domain *dma_dom; + unsigned i, num_pte_pages; + u64 *l2_pde; + u64 address; + + /* + * Currently the DMA aperture must be between 32 MB and 1GB in size + */ + if ((order < 25) || (order > 30)) + return NULL; + + dma_dom = kzalloc(sizeof(struct dma_ops_domain), GFP_KERNEL); + if (!dma_dom) + return NULL; + + spin_lock_init(&dma_dom->domain.lock); + + dma_dom->domain.id = domain_id_alloc(); + if (dma_dom->domain.id == 0) + goto free_dma_dom; + dma_dom->domain.mode = PAGE_MODE_3_LEVEL; + dma_dom->domain.pt_root = (void *)get_zeroed_page(GFP_KERNEL); + dma_dom->domain.priv = dma_dom; + if (!dma_dom->domain.pt_root) + goto free_dma_dom; + dma_dom->aperture_size = (1ULL << order); + dma_dom->bitmap = kzalloc(dma_dom->aperture_size / (PAGE_SIZE * 8), + GFP_KERNEL); + if (!dma_dom->bitmap) + goto free_dma_dom; + /* + * mark the first page as allocated so we never return 0 as + * a valid dma-address. So we can use 0 as error value + */ + dma_dom->bitmap[0] = 1; + dma_dom->next_bit = 0; + + dma_dom->need_flush = false; + dma_dom->target_dev = 0xffff; + + /* Intialize the exclusion range if necessary */ + if (iommu->exclusion_start && + iommu->exclusion_start < dma_dom->aperture_size) { + unsigned long startpage = iommu->exclusion_start >> PAGE_SHIFT; + int pages = iommu_num_pages(iommu->exclusion_start, + iommu->exclusion_length); + dma_ops_reserve_addresses(dma_dom, startpage, pages); + } + + /* + * At the last step, build the page tables so we don't need to + * allocate page table pages in the dma_ops mapping/unmapping + * path. + */ + num_pte_pages = dma_dom->aperture_size / (PAGE_SIZE * 512); + dma_dom->pte_pages = kzalloc(num_pte_pages * sizeof(void *), + GFP_KERNEL); + if (!dma_dom->pte_pages) + goto free_dma_dom; + + l2_pde = (u64 *)get_zeroed_page(GFP_KERNEL); + if (l2_pde == NULL) + goto free_dma_dom; + + dma_dom->domain.pt_root[0] = IOMMU_L2_PDE(virt_to_phys(l2_pde)); + + for (i = 0; i < num_pte_pages; ++i) { + dma_dom->pte_pages[i] = (u64 *)get_zeroed_page(GFP_KERNEL); + if (!dma_dom->pte_pages[i]) + goto free_dma_dom; + address = virt_to_phys(dma_dom->pte_pages[i]); + l2_pde[i] = IOMMU_L1_PDE(address); + } + + return dma_dom; + +free_dma_dom: + dma_ops_domain_free(dma_dom); + + return NULL; +} + +/* + * Find out the protection domain structure for a given PCI device. This + * will give us the pointer to the page table root for example. + */ +static struct protection_domain *domain_for_device(u16 devid) +{ + struct protection_domain *dom; + unsigned long flags; + + read_lock_irqsave(&amd_iommu_devtable_lock, flags); + dom = amd_iommu_pd_table[devid]; + read_unlock_irqrestore(&amd_iommu_devtable_lock, flags); + + return dom; +} + +/* + * If a device is not yet associated with a domain, this function does + * assigns it visible for the hardware + */ +static void set_device_domain(struct amd_iommu *iommu, + struct protection_domain *domain, + u16 devid) +{ + unsigned long flags; + + u64 pte_root = virt_to_phys(domain->pt_root); + + pte_root |= (domain->mode & DEV_ENTRY_MODE_MASK) + << DEV_ENTRY_MODE_SHIFT; + pte_root |= IOMMU_PTE_IR | IOMMU_PTE_IW | IOMMU_PTE_P | IOMMU_PTE_TV; + + write_lock_irqsave(&amd_iommu_devtable_lock, flags); + amd_iommu_dev_table[devid].data[0] = lower_32_bits(pte_root); + amd_iommu_dev_table[devid].data[1] = upper_32_bits(pte_root); + amd_iommu_dev_table[devid].data[2] = domain->id; + + amd_iommu_pd_table[devid] = domain; + write_unlock_irqrestore(&amd_iommu_devtable_lock, flags); + + iommu_queue_inv_dev_entry(iommu, devid); + + iommu->need_sync = 1; +} + +/***************************************************************************** + * + * The next functions belong to the dma_ops mapping/unmapping code. + * + *****************************************************************************/ + +/* + * This function checks if the driver got a valid device from the caller to + * avoid dereferencing invalid pointers. + */ +static bool check_device(struct device *dev) +{ + if (!dev || !dev->dma_mask) + return false; + + return true; +} + +/* + * In this function the list of preallocated protection domains is traversed to + * find the domain for a specific device + */ +static struct dma_ops_domain *find_protection_domain(u16 devid) +{ + struct dma_ops_domain *entry, *ret = NULL; + unsigned long flags; + + if (list_empty(&iommu_pd_list)) + return NULL; + + spin_lock_irqsave(&iommu_pd_list_lock, flags); + + list_for_each_entry(entry, &iommu_pd_list, list) { + if (entry->target_dev == devid) { + ret = entry; + list_del(&ret->list); + break; + } + } + + spin_unlock_irqrestore(&iommu_pd_list_lock, flags); + + return ret; +} + +/* + * In the dma_ops path we only have the struct device. This function + * finds the corresponding IOMMU, the protection domain and the + * requestor id for a given device. + * If the device is not yet associated with a domain this is also done + * in this function. + */ +static int get_device_resources(struct device *dev, + struct amd_iommu **iommu, + struct protection_domain **domain, + u16 *bdf) +{ + struct dma_ops_domain *dma_dom; + struct pci_dev *pcidev; + u16 _bdf; + + *iommu = NULL; + *domain = NULL; + *bdf = 0xffff; + + if (dev->bus != &pci_bus_type) + return 0; + + pcidev = to_pci_dev(dev); + _bdf = calc_devid(pcidev->bus->number, pcidev->devfn); + + /* device not translated by any IOMMU in the system? */ + if (_bdf > amd_iommu_last_bdf) + return 0; + + *bdf = amd_iommu_alias_table[_bdf]; + + *iommu = amd_iommu_rlookup_table[*bdf]; + if (*iommu == NULL) + return 0; + *domain = domain_for_device(*bdf); + if (*domain == NULL) { + dma_dom = find_protection_domain(*bdf); + if (!dma_dom) + dma_dom = (*iommu)->default_dom; + *domain = &dma_dom->domain; + set_device_domain(*iommu, *domain, *bdf); + printk(KERN_INFO "AMD IOMMU: Using protection domain %d for " + "device ", (*domain)->id); + print_devid(_bdf, 1); + } + + return 1; +} + +/* + * This is the generic map function. It maps one 4kb page at paddr to + * the given address in the DMA address space for the domain. + */ +static dma_addr_t dma_ops_domain_map(struct amd_iommu *iommu, + struct dma_ops_domain *dom, + unsigned long address, + phys_addr_t paddr, + int direction) +{ + u64 *pte, __pte; + + WARN_ON(address > dom->aperture_size); + + paddr &= PAGE_MASK; + + pte = dom->pte_pages[IOMMU_PTE_L1_INDEX(address)]; + pte += IOMMU_PTE_L0_INDEX(address); + + __pte = paddr | IOMMU_PTE_P | IOMMU_PTE_FC; + + if (direction == DMA_TO_DEVICE) + __pte |= IOMMU_PTE_IR; + else if (direction == DMA_FROM_DEVICE) + __pte |= IOMMU_PTE_IW; + else if (direction == DMA_BIDIRECTIONAL) + __pte |= IOMMU_PTE_IR | IOMMU_PTE_IW; + + WARN_ON(*pte); + + *pte = __pte; + + return (dma_addr_t)address; +} + +/* + * The generic unmapping function for on page in the DMA address space. + */ +static void dma_ops_domain_unmap(struct amd_iommu *iommu, + struct dma_ops_domain *dom, + unsigned long address) +{ + u64 *pte; + + if (address >= dom->aperture_size) + return; + + WARN_ON(address & 0xfffULL || address > dom->aperture_size); + + pte = dom->pte_pages[IOMMU_PTE_L1_INDEX(address)]; + pte += IOMMU_PTE_L0_INDEX(address); + + WARN_ON(!*pte); + + *pte = 0ULL; +} + +/* + * This function contains common code for mapping of a physically + * contiguous memory region into DMA address space. It is uses by all + * mapping functions provided by this IOMMU driver. + * Must be called with the domain lock held. + */ +static dma_addr_t __map_single(struct device *dev, + struct amd_iommu *iommu, + struct dma_ops_domain *dma_dom, + phys_addr_t paddr, + size_t size, + int dir, + bool align, + u64 dma_mask) +{ + dma_addr_t offset = paddr & ~PAGE_MASK; + dma_addr_t address, start; + unsigned int pages; + unsigned long align_mask = 0; + int i; + + pages = iommu_num_pages(paddr, size); + paddr &= PAGE_MASK; + + if (align) + align_mask = (1UL << get_order(size)) - 1; + + address = dma_ops_alloc_addresses(dev, dma_dom, pages, align_mask, + dma_mask); + if (unlikely(address == bad_dma_address)) + goto out; + + start = address; + for (i = 0; i < pages; ++i) { + dma_ops_domain_map(iommu, dma_dom, start, paddr, dir); + paddr += PAGE_SIZE; + start += PAGE_SIZE; + } + address += offset; + + if (unlikely(dma_dom->need_flush && !amd_iommu_unmap_flush)) { + iommu_flush_tlb(iommu, dma_dom->domain.id); + dma_dom->need_flush = false; + } else if (unlikely(iommu_has_npcache(iommu))) + iommu_flush_pages(iommu, dma_dom->domain.id, address, size); + +out: + return address; +} + +/* + * Does the reverse of the __map_single function. Must be called with + * the domain lock held too + */ +static void __unmap_single(struct amd_iommu *iommu, + struct dma_ops_domain *dma_dom, + dma_addr_t dma_addr, + size_t size, + int dir) +{ + dma_addr_t i, start; + unsigned int pages; + + if ((dma_addr == 0) || (dma_addr + size > dma_dom->aperture_size)) + return; + + pages = iommu_num_pages(dma_addr, size); + dma_addr &= PAGE_MASK; + start = dma_addr; + + for (i = 0; i < pages; ++i) { + dma_ops_domain_unmap(iommu, dma_dom, start); + start += PAGE_SIZE; + } + + dma_ops_free_addresses(dma_dom, dma_addr, pages); + + if (amd_iommu_unmap_flush) + iommu_flush_pages(iommu, dma_dom->domain.id, dma_addr, size); +} + +/* + * The exported map_single function for dma_ops. + */ +static dma_addr_t map_single(struct device *dev, phys_addr_t paddr, + size_t size, int dir) +{ + unsigned long flags; + struct amd_iommu *iommu; + struct protection_domain *domain; + u16 devid; + dma_addr_t addr; + u64 dma_mask; + + if (!check_device(dev)) + return bad_dma_address; + + dma_mask = *dev->dma_mask; + + get_device_resources(dev, &iommu, &domain, &devid); + + if (iommu == NULL || domain == NULL) + /* device not handled by any AMD IOMMU */ + return (dma_addr_t)paddr; + + spin_lock_irqsave(&domain->lock, flags); + addr = __map_single(dev, iommu, domain->priv, paddr, size, dir, false, + dma_mask); + if (addr == bad_dma_address) + goto out; + + if (unlikely(iommu->need_sync)) + iommu_completion_wait(iommu); + +out: + spin_unlock_irqrestore(&domain->lock, flags); + + return addr; +} + +/* + * The exported unmap_single function for dma_ops. + */ +static void unmap_single(struct device *dev, dma_addr_t dma_addr, + size_t size, int dir) +{ + unsigned long flags; + struct amd_iommu *iommu; + struct protection_domain *domain; + u16 devid; + + if (!check_device(dev) || + !get_device_resources(dev, &iommu, &domain, &devid)) + /* device not handled by any AMD IOMMU */ + return; + + spin_lock_irqsave(&domain->lock, flags); + + __unmap_single(iommu, domain->priv, dma_addr, size, dir); + + if (unlikely(iommu->need_sync)) + iommu_completion_wait(iommu); + + spin_unlock_irqrestore(&domain->lock, flags); +} + +/* + * This is a special map_sg function which is used if we should map a + * device which is not handled by an AMD IOMMU in the system. + */ +static int map_sg_no_iommu(struct device *dev, struct scatterlist *sglist, + int nelems, int dir) +{ + struct scatterlist *s; + int i; + + for_each_sg(sglist, s, nelems, i) { + s->dma_address = (dma_addr_t)sg_phys(s); + s->dma_length = s->length; + } + + return nelems; +} + +/* + * The exported map_sg function for dma_ops (handles scatter-gather + * lists). + */ +static int map_sg(struct device *dev, struct scatterlist *sglist, + int nelems, int dir) +{ + unsigned long flags; + struct amd_iommu *iommu; + struct protection_domain *domain; + u16 devid; + int i; + struct scatterlist *s; + phys_addr_t paddr; + int mapped_elems = 0; + u64 dma_mask; + + if (!check_device(dev)) + return 0; + + dma_mask = *dev->dma_mask; + + get_device_resources(dev, &iommu, &domain, &devid); + + if (!iommu || !domain) + return map_sg_no_iommu(dev, sglist, nelems, dir); + + spin_lock_irqsave(&domain->lock, flags); + + for_each_sg(sglist, s, nelems, i) { + paddr = sg_phys(s); + + s->dma_address = __map_single(dev, iommu, domain->priv, + paddr, s->length, dir, false, + dma_mask); + + if (s->dma_address) { + s->dma_length = s->length; + mapped_elems++; + } else + goto unmap; + } + + if (unlikely(iommu->need_sync)) + iommu_completion_wait(iommu); + +out: + spin_unlock_irqrestore(&domain->lock, flags); + + return mapped_elems; +unmap: + for_each_sg(sglist, s, mapped_elems, i) { + if (s->dma_address) + __unmap_single(iommu, domain->priv, s->dma_address, + s->dma_length, dir); + s->dma_address = s->dma_length = 0; + } + + mapped_elems = 0; + + goto out; +} + +/* + * The exported map_sg function for dma_ops (handles scatter-gather + * lists). + */ +static void unmap_sg(struct device *dev, struct scatterlist *sglist, + int nelems, int dir) +{ + unsigned long flags; + struct amd_iommu *iommu; + struct protection_domain *domain; + struct scatterlist *s; + u16 devid; + int i; + + if (!check_device(dev) || + !get_device_resources(dev, &iommu, &domain, &devid)) + return; + + spin_lock_irqsave(&domain->lock, flags); + + for_each_sg(sglist, s, nelems, i) { + __unmap_single(iommu, domain->priv, s->dma_address, + s->dma_length, dir); + s->dma_address = s->dma_length = 0; + } + + if (unlikely(iommu->need_sync)) + iommu_completion_wait(iommu); + + spin_unlock_irqrestore(&domain->lock, flags); +} + +/* + * The exported alloc_coherent function for dma_ops. + */ +static void *alloc_coherent(struct device *dev, size_t size, + dma_addr_t *dma_addr, gfp_t flag) +{ + unsigned long flags; + void *virt_addr; + struct amd_iommu *iommu; + struct protection_domain *domain; + u16 devid; + phys_addr_t paddr; + u64 dma_mask = dev->coherent_dma_mask; + + if (!check_device(dev)) + return NULL; + + if (!get_device_resources(dev, &iommu, &domain, &devid)) + flag &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32); + + flag |= __GFP_ZERO; + virt_addr = (void *)__get_free_pages(flag, get_order(size)); + if (!virt_addr) + return 0; + + paddr = virt_to_phys(virt_addr); + + if (!iommu || !domain) { + *dma_addr = (dma_addr_t)paddr; + return virt_addr; + } + + if (!dma_mask) + dma_mask = *dev->dma_mask; + + spin_lock_irqsave(&domain->lock, flags); + + *dma_addr = __map_single(dev, iommu, domain->priv, paddr, + size, DMA_BIDIRECTIONAL, true, dma_mask); + + if (*dma_addr == bad_dma_address) { + free_pages((unsigned long)virt_addr, get_order(size)); + virt_addr = NULL; + goto out; + } + + if (unlikely(iommu->need_sync)) + iommu_completion_wait(iommu); + +out: + spin_unlock_irqrestore(&domain->lock, flags); + + return virt_addr; +} + +/* + * The exported free_coherent function for dma_ops. + */ +static void free_coherent(struct device *dev, size_t size, + void *virt_addr, dma_addr_t dma_addr) +{ + unsigned long flags; + struct amd_iommu *iommu; + struct protection_domain *domain; + u16 devid; + + if (!check_device(dev)) + return; + + get_device_resources(dev, &iommu, &domain, &devid); + + if (!iommu || !domain) + goto free_mem; + + spin_lock_irqsave(&domain->lock, flags); + + __unmap_single(iommu, domain->priv, dma_addr, size, DMA_BIDIRECTIONAL); + + if (unlikely(iommu->need_sync)) + iommu_completion_wait(iommu); + + spin_unlock_irqrestore(&domain->lock, flags); + +free_mem: + free_pages((unsigned long)virt_addr, get_order(size)); +} + +/* + * This function is called by the DMA layer to find out if we can handle a + * particular device. It is part of the dma_ops. + */ +static int amd_iommu_dma_supported(struct device *dev, u64 mask) +{ + u16 bdf; + struct pci_dev *pcidev; + + /* No device or no PCI device */ + if (!dev || dev->bus != &pci_bus_type) + return 0; + + pcidev = to_pci_dev(dev); + + bdf = calc_devid(pcidev->bus->number, pcidev->devfn); + + /* Out of our scope? */ + if (bdf > amd_iommu_last_bdf) + return 0; + + return 1; +} + +/* + * The function for pre-allocating protection domains. + * + * If the driver core informs the DMA layer if a driver grabs a device + * we don't need to preallocate the protection domains anymore. + * For now we have to. + */ +void prealloc_protection_domains(void) +{ + struct pci_dev *dev = NULL; + struct dma_ops_domain *dma_dom; + struct amd_iommu *iommu; + int order = amd_iommu_aperture_order; + u16 devid; + + while ((dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev)) != NULL) { + devid = (dev->bus->number << 8) | dev->devfn; + if (devid > amd_iommu_last_bdf) + continue; + devid = amd_iommu_alias_table[devid]; + if (domain_for_device(devid)) + continue; + iommu = amd_iommu_rlookup_table[devid]; + if (!iommu) + continue; + dma_dom = dma_ops_domain_alloc(iommu, order); + if (!dma_dom) + continue; + init_unity_mappings_for_device(dma_dom, devid); + dma_dom->target_dev = devid; + + list_add_tail(&dma_dom->list, &iommu_pd_list); + } +} + +static struct dma_mapping_ops amd_iommu_dma_ops = { + .alloc_coherent = alloc_coherent, + .free_coherent = free_coherent, + .map_single = map_single, + .unmap_single = unmap_single, + .map_sg = map_sg, + .unmap_sg = unmap_sg, + .dma_supported = amd_iommu_dma_supported, +}; + +/* + * The function which clues the AMD IOMMU driver into dma_ops. + */ +int __init amd_iommu_init_dma_ops(void) +{ + struct amd_iommu *iommu; + int order = amd_iommu_aperture_order; + int ret; + + /* + * first allocate a default protection domain for every IOMMU we + * found in the system. Devices not assigned to any other + * protection domain will be assigned to the default one. + */ + list_for_each_entry(iommu, &amd_iommu_list, list) { + iommu->default_dom = dma_ops_domain_alloc(iommu, order); + if (iommu->default_dom == NULL) + return -ENOMEM; + ret = iommu_init_unity_mappings(iommu); + if (ret) + goto free_domains; + } + + /* + * If device isolation is enabled, pre-allocate the protection + * domains for each device. + */ + if (amd_iommu_isolate) + prealloc_protection_domains(); + + iommu_detected = 1; + force_iommu = 1; + bad_dma_address = 0; +#ifdef CONFIG_GART_IOMMU + gart_iommu_aperture_disabled = 1; + gart_iommu_aperture = 0; +#endif + + /* Make the driver finally visible to the drivers */ + dma_ops = &amd_iommu_dma_ops; + + return 0; + +free_domains: + + list_for_each_entry(iommu, &amd_iommu_list, list) { + if (iommu->default_dom) + dma_ops_domain_free(iommu->default_dom); + } + + return ret; +} |