linux/arch/x86/kernel/amd_iommu.c

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/*
* 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 & (1UL << 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);
if (!ret)
iommu->need_sync = 1;
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);
spin_lock_irqsave(&iommu->lock, flags);
if (!iommu->need_sync)
goto out;
iommu->need_sync = 0;
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);
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);
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, PAGE_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(phys_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);
if (address >= dom->next_bit)
dom->need_flush = true;
}
/****************************************************************************
*
* 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,
PAGE_SIZE);
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);
}
/*****************************************************************************
*
* 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);
}
if (domain_for_device(_bdf) == NULL)
set_device_domain(*iommu, *domain, _bdf);
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, PAGE_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, PAGE_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 || dma_dom->need_flush) {
iommu_flush_pages(iommu, dma_dom->domain.id, dma_addr, size);
dma_dom->need_flush = false;
}
}
/*
* 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;
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);
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;
}
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;
}
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;
}
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);
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;
}