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Diffstat (limited to 'arch/x86/kernel/amd_iommu.c')
-rw-r--r--arch/x86/kernel/amd_iommu.c283
1 files changed, 249 insertions, 34 deletions
diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index f2766d84c7a..042fdc27bc9 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -23,36 +23,49 @@
#include <linux/scatterlist.h>
#include <linux/iommu-helper.h>
#include <asm/proto.h>
-#include <asm/gart.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 to_pages(addr, size) \
- (round_up(((addr) & ~PAGE_MASK) + (size), PAGE_SIZE) >> PAGE_SHIFT)
+#define EXIT_LOOP_COUNT 10000000
static DEFINE_RWLOCK(amd_iommu_devtable_lock);
-struct command {
+/*
+ * 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;
}
-static int __iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
+/****************************************************************************
+ *
+ * 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);
+ 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);
@@ -63,7 +76,11 @@ static int __iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
return 0;
}
-static int iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
+/*
+ * 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;
@@ -75,35 +92,59 @@ static int iommu_queue_command(struct amd_iommu *iommu, struct command *cmd)
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;
- struct command cmd;
- volatile u64 ready = 0;
- unsigned long ready_phys = virt_to_phys(&ready);
+ 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] = LOW_U32(ready_phys) | CMD_COMPL_WAIT_STORE_MASK;
- cmd.data[1] = HIGH_U32(ready_phys);
- cmd.data[2] = 1; /* value written to 'ready' */
+ cmd.data[0] = CMD_COMPL_WAIT_INT_MASK;
CMD_SET_TYPE(&cmd, CMD_COMPL_WAIT);
iommu->need_sync = 0;
- ret = iommu_queue_command(iommu, &cmd);
+ spin_lock_irqsave(&iommu->lock, flags);
+
+ ret = __iommu_queue_command(iommu, &cmd);
if (ret)
- return 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;
+ }
- while (!ready)
- cpu_relax();
+ /* 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 command cmd;
+ struct iommu_cmd cmd;
+ int ret;
BUG_ON(iommu == NULL);
@@ -111,37 +152,50 @@ static int iommu_queue_inv_dev_entry(struct amd_iommu *iommu, u16 devid)
CMD_SET_TYPE(&cmd, CMD_INV_DEV_ENTRY);
cmd.data[0] = devid;
+ ret = iommu_queue_command(iommu, &cmd);
+
iommu->need_sync = 1;
- return 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 command cmd;
+ 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] = LOW_U32(address);
- cmd.data[3] = HIGH_U32(address);
- if (s)
+ 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)
+ 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 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 = to_pages(address, size);
+ unsigned pages = iommu_num_pages(address, size);
address &= PAGE_MASK;
@@ -159,6 +213,20 @@ static int iommu_flush_pages(struct amd_iommu *iommu, u16 domid,
return 0;
}
+/****************************************************************************
+ *
+ * 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,
@@ -209,6 +277,10 @@ static int iommu_map(struct protection_domain *dom,
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)
{
@@ -223,6 +295,12 @@ static int iommu_for_unity_map(struct amd_iommu *iommu,
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;
@@ -239,6 +317,10 @@ static int iommu_init_unity_mappings(struct amd_iommu *iommu)
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)
{
@@ -261,6 +343,9 @@ static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
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)
{
@@ -278,12 +363,26 @@ static int init_unity_mappings_for_device(struct dma_ops_domain *dma_dom,
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.
+ *
+ ****************************************************************************/
static unsigned long dma_mask_to_pages(unsigned long mask)
{
return (mask >> PAGE_SHIFT) +
(PAGE_ALIGN(mask & ~PAGE_MASK) >> PAGE_SHIFT);
}
+/*
+ * 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)
@@ -317,6 +416,11 @@ static unsigned long dma_ops_alloc_addresses(struct device *dev,
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)
@@ -325,6 +429,16 @@ static void dma_ops_free_addresses(struct dma_ops_domain *dom,
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;
@@ -342,6 +456,10 @@ static u16 domain_id_alloc(void)
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)
@@ -382,6 +500,10 @@ static void dma_ops_free_pagetable(struct dma_ops_domain *dma_dom)
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)
@@ -396,6 +518,11 @@ static void dma_ops_domain_free(struct dma_ops_domain *dom)
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)
{
@@ -436,14 +563,20 @@ static struct dma_ops_domain *dma_ops_domain_alloc(struct amd_iommu *iommu,
dma_dom->bitmap[0] = 1;
dma_dom->next_bit = 0;
+ /* 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 = to_pages(iommu->exclusion_start,
- iommu->exclusion_length);
+ 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);
@@ -472,6 +605,10 @@ 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;
@@ -484,6 +621,10 @@ static struct protection_domain *domain_for_device(u16 devid)
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)
@@ -508,6 +649,19 @@ static void set_device_domain(struct amd_iommu *iommu,
iommu->need_sync = 1;
}
+/*****************************************************************************
+ *
+ * The next functions belong to the dma_ops mapping/unmapping code.
+ *
+ *****************************************************************************/
+
+/*
+ * 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,
@@ -520,9 +674,10 @@ static int get_device_resources(struct device *dev,
BUG_ON(!dev || dev->bus != &pci_bus_type || !dev->dma_mask);
pcidev = to_pci_dev(dev);
- _bdf = (pcidev->bus->number << 8) | pcidev->devfn;
+ _bdf = calc_devid(pcidev->bus->number, pcidev->devfn);
- if (_bdf >= amd_iommu_last_bdf) {
+ /* device not translated by any IOMMU in the system? */
+ if (_bdf > amd_iommu_last_bdf) {
*iommu = NULL;
*domain = NULL;
*bdf = 0xffff;
@@ -547,6 +702,10 @@ static int get_device_resources(struct device *dev,
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,
@@ -578,6 +737,9 @@ static dma_addr_t dma_ops_domain_map(struct amd_iommu *iommu,
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)
@@ -597,6 +759,12 @@ static void dma_ops_domain_unmap(struct amd_iommu *iommu,
*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,
@@ -609,7 +777,7 @@ static dma_addr_t __map_single(struct device *dev,
unsigned int pages;
int i;
- pages = to_pages(paddr, size);
+ pages = iommu_num_pages(paddr, size);
paddr &= PAGE_MASK;
address = dma_ops_alloc_addresses(dev, dma_dom, pages);
@@ -628,6 +796,10 @@ 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,
@@ -640,7 +812,7 @@ static void __unmap_single(struct amd_iommu *iommu,
if ((dma_addr == 0) || (dma_addr + size > dma_dom->aperture_size))
return;
- pages = to_pages(dma_addr, size);
+ pages = iommu_num_pages(dma_addr, size);
dma_addr &= PAGE_MASK;
start = dma_addr;
@@ -652,6 +824,9 @@ static void __unmap_single(struct amd_iommu *iommu,
dma_ops_free_addresses(dma_dom, dma_addr, pages);
}
+/*
+ * 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)
{
@@ -664,6 +839,7 @@ static dma_addr_t map_single(struct device *dev, phys_addr_t paddr,
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);
@@ -683,6 +859,9 @@ out:
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)
{
@@ -692,6 +871,7 @@ static void unmap_single(struct device *dev, dma_addr_t dma_addr,
u16 devid;
if (!get_device_resources(dev, &iommu, &domain, &devid))
+ /* device not handled by any AMD IOMMU */
return;
spin_lock_irqsave(&domain->lock, flags);
@@ -706,6 +886,10 @@ static void unmap_single(struct device *dev, dma_addr_t dma_addr,
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)
{
@@ -720,6 +904,10 @@ static int map_sg_no_iommu(struct device *dev, struct scatterlist *sglist,
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)
{
@@ -775,6 +963,10 @@ unmap:
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)
{
@@ -804,6 +996,9 @@ static void unmap_sg(struct device *dev, struct scatterlist *sglist,
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)
{
@@ -851,6 +1046,11 @@ out:
return virt_addr;
}
+/*
+ * The exported free_coherent function for dma_ops.
+ * FIXME: fix the generic x86 DMA layer so that it actually calls that
+ * function.
+ */
static void free_coherent(struct device *dev, size_t size,
void *virt_addr, dma_addr_t dma_addr)
{
@@ -879,6 +1079,8 @@ free_mem:
}
/*
+ * 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.
@@ -893,7 +1095,7 @@ void prealloc_protection_domains(void)
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)
+ if (devid > amd_iommu_last_bdf)
continue;
devid = amd_iommu_alias_table[devid];
if (domain_for_device(devid))
@@ -921,12 +1123,20 @@ static struct dma_mapping_ops amd_iommu_dma_ops = {
.unmap_sg = unmap_sg,
};
+/*
+ * 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)
@@ -936,6 +1146,10 @@ int __init amd_iommu_init_dma_ops(void)
goto free_domains;
}
+ /*
+ * If device isolation is enabled, pre-allocate the protection
+ * domains for each device.
+ */
if (amd_iommu_isolate)
prealloc_protection_domains();
@@ -947,6 +1161,7 @@ int __init amd_iommu_init_dma_ops(void)
gart_iommu_aperture = 0;
#endif
+ /* Make the driver finally visible to the drivers */
dma_ops = &amd_iommu_dma_ops;
return 0;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-25 11:32:55 +0000