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authorAlex Shi <alex.shi@linaro.org>2016-04-17 13:11:37 +0800
committerAlex Shi <alex.shi@linaro.org>2016-04-17 13:11:37 +0800
commite591426df6a0bad7738bfd44685b125d2b8d2a08 (patch)
treee58833683e06bcb026c581ec04897f9885dca4a4
parentc789ced3a2a574ae52495c913a918e34d32d7bdd (diff)
parent7459e9f095c4f18456653dc0ae87dcba84b497e3 (diff)
downloadlinux-linaro-stable-linux-linaro-lsk-v4.1-android-test.tar.gz
Merge branch 'linux-linaro-lsk-v4.1' into linux-linaro-lsk-v4.1-androidlinux-linaro-lsk-v4.1-android-test
-rw-r--r--arch/arm64/Kconfig2
-rw-r--r--arch/arm64/include/asm/dma-mapping.h27
-rw-r--r--arch/arm64/mm/dma-mapping.c549
-rw-r--r--drivers/iommu/Kconfig7
-rw-r--r--drivers/iommu/Makefile1
-rw-r--r--drivers/iommu/dma-iommu.c524
-rw-r--r--include/linux/dma-iommu.h85
-rw-r--r--include/linux/iommu.h1
8 files changed, 1189 insertions, 7 deletions
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 813a6fc..c8f0bb1 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1,5 +1,6 @@
config ARM64
def_bool y
+ select ACPI_CCA_REQUIRED if ACPI
select ACPI_GENERIC_GSI if ACPI
select ACPI_REDUCED_HARDWARE_ONLY if ACPI
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
@@ -74,6 +75,7 @@ config ARM64
select HAVE_PERF_USER_STACK_DUMP
select HAVE_RCU_TABLE_FREE
select HAVE_SYSCALL_TRACEPOINTS
+ select IOMMU_DMA if IOMMU_SUPPORT
select IRQ_DOMAIN
select MODULES_USE_ELF_RELA
select NO_BOOTMEM
diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
index 9437e3d..7f9edcb 100644
--- a/arch/arm64/include/asm/dma-mapping.h
+++ b/arch/arm64/include/asm/dma-mapping.h
@@ -18,6 +18,7 @@
#ifdef __KERNEL__
+#include <linux/acpi.h>
#include <linux/types.h>
#include <linux/vmalloc.h>
@@ -28,13 +29,23 @@
#define DMA_ERROR_CODE (~(dma_addr_t)0)
extern struct dma_map_ops *dma_ops;
+extern struct dma_map_ops dummy_dma_ops;
static inline struct dma_map_ops *__generic_dma_ops(struct device *dev)
{
- if (unlikely(!dev) || !dev->archdata.dma_ops)
+ if (unlikely(!dev))
return dma_ops;
- else
+ else if (dev->archdata.dma_ops)
return dev->archdata.dma_ops;
+ else if (acpi_disabled)
+ return dma_ops;
+
+ /*
+ * When ACPI is enabled, if arch_set_dma_ops is not called,
+ * we will disable device DMA capability by setting it
+ * to dummy_dma_ops.
+ */
+ return &dummy_dma_ops;
}
static inline struct dma_map_ops *get_dma_ops(struct device *dev)
@@ -45,13 +56,15 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev)
return __generic_dma_ops(dev);
}
-static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
- struct iommu_ops *iommu, bool coherent)
-{
- dev->archdata.dma_coherent = coherent;
-}
+void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+ struct iommu_ops *iommu, bool coherent);
#define arch_setup_dma_ops arch_setup_dma_ops
+#ifdef CONFIG_IOMMU_DMA
+void arch_teardown_dma_ops(struct device *dev);
+#define arch_teardown_dma_ops arch_teardown_dma_ops
+#endif
+
/* do not use this function in a driver */
static inline bool is_device_dma_coherent(struct device *dev)
{
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index cdbd4db..632d5ad 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -414,6 +414,98 @@ out:
return -ENOMEM;
}
+/********************************************
+ * The following APIs are for dummy DMA ops *
+ ********************************************/
+
+static void *__dummy_alloc(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flags,
+ struct dma_attrs *attrs)
+{
+ return NULL;
+}
+
+static void __dummy_free(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle,
+ struct dma_attrs *attrs)
+{
+}
+
+static int __dummy_mmap(struct device *dev,
+ struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ struct dma_attrs *attrs)
+{
+ return -ENXIO;
+}
+
+static dma_addr_t __dummy_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ return DMA_ERROR_CODE;
+}
+
+static void __dummy_unmap_page(struct device *dev, dma_addr_t dev_addr,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+}
+
+static int __dummy_map_sg(struct device *dev, struct scatterlist *sgl,
+ int nelems, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ return 0;
+}
+
+static void __dummy_unmap_sg(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+}
+
+static void __dummy_sync_single(struct device *dev,
+ dma_addr_t dev_addr, size_t size,
+ enum dma_data_direction dir)
+{
+}
+
+static void __dummy_sync_sg(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir)
+{
+}
+
+static int __dummy_mapping_error(struct device *hwdev, dma_addr_t dma_addr)
+{
+ return 1;
+}
+
+static int __dummy_dma_supported(struct device *hwdev, u64 mask)
+{
+ return 0;
+}
+
+struct dma_map_ops dummy_dma_ops = {
+ .alloc = __dummy_alloc,
+ .free = __dummy_free,
+ .mmap = __dummy_mmap,
+ .map_page = __dummy_map_page,
+ .unmap_page = __dummy_unmap_page,
+ .map_sg = __dummy_map_sg,
+ .unmap_sg = __dummy_unmap_sg,
+ .sync_single_for_cpu = __dummy_sync_single,
+ .sync_single_for_device = __dummy_sync_single,
+ .sync_sg_for_cpu = __dummy_sync_sg,
+ .sync_sg_for_device = __dummy_sync_sg,
+ .mapping_error = __dummy_mapping_error,
+ .dma_supported = __dummy_dma_supported,
+};
+EXPORT_SYMBOL(dummy_dma_ops);
+
static int __init arm64_dma_init(void)
{
int ret;
@@ -434,3 +526,460 @@ static int __init dma_debug_do_init(void)
return 0;
}
fs_initcall(dma_debug_do_init);
+
+
+#ifdef CONFIG_IOMMU_DMA
+#include <linux/dma-iommu.h>
+#include <linux/platform_device.h>
+#include <linux/amba/bus.h>
+
+/* Thankfully, all cache ops are by VA so we can ignore phys here */
+static void flush_page(struct device *dev, const void *virt, phys_addr_t phys)
+{
+ __dma_flush_range(virt, virt + PAGE_SIZE);
+}
+
+static void *__iommu_alloc_attrs(struct device *dev, size_t size,
+ dma_addr_t *handle, gfp_t gfp,
+ struct dma_attrs *attrs)
+{
+ bool coherent = is_device_dma_coherent(dev);
+ int ioprot = dma_direction_to_prot(DMA_BIDIRECTIONAL, coherent);
+ void *addr;
+
+ if (WARN(!dev, "cannot create IOMMU mapping for unknown device\n"))
+ return NULL;
+ /*
+ * Some drivers rely on this, and we probably don't want the
+ * possibility of stale kernel data being read by devices anyway.
+ */
+ gfp |= __GFP_ZERO;
+
+ if (gfp & __GFP_WAIT) {
+ struct page **pages;
+ pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, coherent);
+
+ pages = iommu_dma_alloc(dev, size, gfp, ioprot, handle,
+ flush_page);
+ if (!pages)
+ return NULL;
+
+ addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
+ __builtin_return_address(0));
+ if (!addr)
+ iommu_dma_free(dev, pages, size, handle);
+ } else {
+ struct page *page;
+ /*
+ * In atomic context we can't remap anything, so we'll only
+ * get the virtually contiguous buffer we need by way of a
+ * physically contiguous allocation.
+ */
+ if (coherent) {
+ page = alloc_pages(gfp, get_order(size));
+ addr = page ? page_address(page) : NULL;
+ } else {
+ addr = __alloc_from_pool(size, &page, gfp);
+ }
+ if (!addr)
+ return NULL;
+
+ *handle = iommu_dma_map_page(dev, page, 0, size, ioprot);
+ if (iommu_dma_mapping_error(dev, *handle)) {
+ if (coherent)
+ __free_pages(page, get_order(size));
+ else
+ __free_from_pool(addr, size);
+ addr = NULL;
+ }
+ }
+ return addr;
+}
+
+static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
+ dma_addr_t handle, struct dma_attrs *attrs)
+{
+ /*
+ * @cpu_addr will be one of 3 things depending on how it was allocated:
+ * - A remapped array of pages from iommu_dma_alloc(), for all
+ * non-atomic allocations.
+ * - A non-cacheable alias from the atomic pool, for atomic
+ * allocations by non-coherent devices.
+ * - A normal lowmem address, for atomic allocations by
+ * coherent devices.
+ * Hence how dodgy the below logic looks...
+ */
+ if (__in_atomic_pool(cpu_addr, size)) {
+ iommu_dma_unmap_page(dev, handle, size, 0, NULL);
+ __free_from_pool(cpu_addr, size);
+ } else if (is_vmalloc_addr(cpu_addr)){
+ struct vm_struct *area = find_vm_area(cpu_addr);
+
+ if (WARN_ON(!area || !area->pages))
+ return;
+ iommu_dma_free(dev, area->pages, size, &handle);
+ dma_common_free_remap(cpu_addr, size, VM_USERMAP);
+ } else {
+ iommu_dma_unmap_page(dev, handle, size, 0, NULL);
+ __free_pages(virt_to_page(cpu_addr), get_order(size));
+ }
+}
+
+static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ struct dma_attrs *attrs)
+{
+ struct vm_struct *area;
+ int ret;
+
+ vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
+ is_device_dma_coherent(dev));
+
+ if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
+ return ret;
+
+ area = find_vm_area(cpu_addr);
+ if (WARN_ON(!area || !area->pages))
+ return -ENXIO;
+
+ return iommu_dma_mmap(area->pages, size, vma);
+}
+
+static int __iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
+ void *cpu_addr, dma_addr_t dma_addr,
+ size_t size, struct dma_attrs *attrs)
+{
+ unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ struct vm_struct *area = find_vm_area(cpu_addr);
+
+ if (WARN_ON(!area || !area->pages))
+ return -ENXIO;
+
+ return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size,
+ GFP_KERNEL);
+}
+
+static void __iommu_sync_single_for_cpu(struct device *dev,
+ dma_addr_t dev_addr, size_t size,
+ enum dma_data_direction dir)
+{
+ phys_addr_t phys;
+
+ if (is_device_dma_coherent(dev))
+ return;
+
+ phys = iommu_iova_to_phys(iommu_get_domain_for_dev(dev), dev_addr);
+ __dma_unmap_area(phys_to_virt(phys), size, dir);
+}
+
+static void __iommu_sync_single_for_device(struct device *dev,
+ dma_addr_t dev_addr, size_t size,
+ enum dma_data_direction dir)
+{
+ phys_addr_t phys;
+
+ if (is_device_dma_coherent(dev))
+ return;
+
+ phys = iommu_iova_to_phys(iommu_get_domain_for_dev(dev), dev_addr);
+ __dma_map_area(phys_to_virt(phys), size, dir);
+}
+
+static dma_addr_t __iommu_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ bool coherent = is_device_dma_coherent(dev);
+ int prot = dma_direction_to_prot(dir, coherent);
+ dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);
+
+ if (!iommu_dma_mapping_error(dev, dev_addr) &&
+ !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
+ __iommu_sync_single_for_device(dev, dev_addr, size, dir);
+
+ return dev_addr;
+}
+
+static void __iommu_unmap_page(struct device *dev, dma_addr_t dev_addr,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
+ __iommu_sync_single_for_cpu(dev, dev_addr, size, dir);
+
+ iommu_dma_unmap_page(dev, dev_addr, size, dir, attrs);
+}
+
+static void __iommu_sync_sg_for_cpu(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir)
+{
+ struct scatterlist *sg;
+ int i;
+
+ if (is_device_dma_coherent(dev))
+ return;
+
+ for_each_sg(sgl, sg, nelems, i)
+ __dma_unmap_area(sg_virt(sg), sg->length, dir);
+}
+
+static void __iommu_sync_sg_for_device(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir)
+{
+ struct scatterlist *sg;
+ int i;
+
+ if (is_device_dma_coherent(dev))
+ return;
+
+ for_each_sg(sgl, sg, nelems, i)
+ __dma_map_area(sg_virt(sg), sg->length, dir);
+}
+
+static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
+ int nelems, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ bool coherent = is_device_dma_coherent(dev);
+
+ if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
+ __iommu_sync_sg_for_device(dev, sgl, nelems, dir);
+
+ return iommu_dma_map_sg(dev, sgl, nelems,
+ dma_direction_to_prot(dir, coherent));
+}
+
+static void __iommu_unmap_sg_attrs(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
+ __iommu_sync_sg_for_cpu(dev, sgl, nelems, dir);
+
+ iommu_dma_unmap_sg(dev, sgl, nelems, dir, attrs);
+}
+
+static struct dma_map_ops iommu_dma_ops = {
+ .alloc = __iommu_alloc_attrs,
+ .free = __iommu_free_attrs,
+ .mmap = __iommu_mmap_attrs,
+ .get_sgtable = __iommu_get_sgtable,
+ .map_page = __iommu_map_page,
+ .unmap_page = __iommu_unmap_page,
+ .map_sg = __iommu_map_sg_attrs,
+ .unmap_sg = __iommu_unmap_sg_attrs,
+ .sync_single_for_cpu = __iommu_sync_single_for_cpu,
+ .sync_single_for_device = __iommu_sync_single_for_device,
+ .sync_sg_for_cpu = __iommu_sync_sg_for_cpu,
+ .sync_sg_for_device = __iommu_sync_sg_for_device,
+ .dma_supported = iommu_dma_supported,
+ .mapping_error = iommu_dma_mapping_error,
+};
+
+/*
+ * TODO: Right now __iommu_setup_dma_ops() gets called too early to do
+ * everything it needs to - the device is only partially created and the
+ * IOMMU driver hasn't seen it yet, so it can't have a group. Thus we
+ * need this delayed attachment dance. Once IOMMU probe ordering is sorted
+ * to move the arch_setup_dma_ops() call later, all the notifier bits below
+ * become unnecessary, and will go away.
+ */
+struct iommu_dma_notifier_data {
+ struct list_head list;
+ struct device *dev;
+ const struct iommu_ops *ops;
+ u64 dma_base;
+ u64 size;
+};
+static LIST_HEAD(iommu_dma_masters);
+static DEFINE_MUTEX(iommu_dma_notifier_lock);
+
+/*
+ * Temporarily "borrow" a domain feature flag to to tell if we had to resort
+ * to creating our own domain here, in case we need to clean it up again.
+ */
+#define __IOMMU_DOMAIN_FAKE_DEFAULT (1U << 31)
+
+static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops,
+ u64 dma_base, u64 size)
+{
+ struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+
+ /*
+ * Best case: The device is either part of a group which was
+ * already attached to a domain in a previous call, or it's
+ * been put in a default DMA domain by the IOMMU core.
+ */
+ if (!domain) {
+ /*
+ * Urgh. The IOMMU core isn't going to do default domains
+ * for non-PCI devices anyway, until it has some means of
+ * abstracting the entirely implementation-specific
+ * sideband data/SoC topology/unicorn dust that may or
+ * may not differentiate upstream masters.
+ * So until then, HORRIBLE HACKS!
+ */
+ domain = ops->domain_alloc(IOMMU_DOMAIN_DMA);
+ if (!domain)
+ goto out_no_domain;
+
+ domain->ops = ops;
+ domain->type = IOMMU_DOMAIN_DMA | __IOMMU_DOMAIN_FAKE_DEFAULT;
+
+ if (iommu_attach_device(domain, dev))
+ goto out_put_domain;
+ }
+
+ if (iommu_dma_init_domain(domain, dma_base, size))
+ goto out_detach;
+
+ dev->archdata.dma_ops = &iommu_dma_ops;
+ return true;
+
+out_detach:
+ iommu_detach_device(domain, dev);
+out_put_domain:
+ if (domain->type & __IOMMU_DOMAIN_FAKE_DEFAULT)
+ iommu_domain_free(domain);
+out_no_domain:
+ pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
+ dev_name(dev));
+ return false;
+}
+
+static void queue_iommu_attach(struct device *dev, const struct iommu_ops *ops,
+ u64 dma_base, u64 size)
+{
+ struct iommu_dma_notifier_data *iommudata;
+
+ iommudata = kzalloc(sizeof(*iommudata), GFP_KERNEL);
+ if (!iommudata)
+ return;
+
+ iommudata->dev = dev;
+ iommudata->ops = ops;
+ iommudata->dma_base = dma_base;
+ iommudata->size = size;
+
+ mutex_lock(&iommu_dma_notifier_lock);
+ list_add(&iommudata->list, &iommu_dma_masters);
+ mutex_unlock(&iommu_dma_notifier_lock);
+}
+
+static int __iommu_attach_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct iommu_dma_notifier_data *master, *tmp;
+
+ if (action != BUS_NOTIFY_ADD_DEVICE)
+ return 0;
+
+ mutex_lock(&iommu_dma_notifier_lock);
+ list_for_each_entry_safe(master, tmp, &iommu_dma_masters, list) {
+ if (do_iommu_attach(master->dev, master->ops,
+ master->dma_base, master->size)) {
+ list_del(&master->list);
+ kfree(master);
+ }
+ }
+ mutex_unlock(&iommu_dma_notifier_lock);
+ return 0;
+}
+
+static int register_iommu_dma_ops_notifier(struct bus_type *bus)
+{
+ struct notifier_block *nb = kzalloc(sizeof(*nb), GFP_KERNEL);
+ int ret;
+
+ if (!nb)
+ return -ENOMEM;
+ /*
+ * The device must be attached to a domain before the driver probe
+ * routine gets a chance to start allocating DMA buffers. However,
+ * the IOMMU driver also needs a chance to configure the iommu_group
+ * via its add_device callback first, so we need to make the attach
+ * happen between those two points. Since the IOMMU core uses a bus
+ * notifier with default priority for add_device, do the same but
+ * with a lower priority to ensure the appropriate ordering.
+ */
+ nb->notifier_call = __iommu_attach_notifier;
+ nb->priority = -100;
+
+ ret = bus_register_notifier(bus, nb);
+ if (ret) {
+ pr_warn("Failed to register DMA domain notifier; IOMMU DMA ops unavailable on bus '%s'\n",
+ bus->name);
+ kfree(nb);
+ }
+ return ret;
+}
+
+static int __init __iommu_dma_init(void)
+{
+ int ret;
+
+ ret = iommu_dma_init();
+ if (!ret)
+ ret = register_iommu_dma_ops_notifier(&platform_bus_type);
+ if (!ret)
+ ret = register_iommu_dma_ops_notifier(&amba_bustype);
+ return ret;
+}
+arch_initcall(__iommu_dma_init);
+
+static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+ const struct iommu_ops *ops)
+{
+ struct iommu_group *group;
+
+ if (!ops)
+ return;
+ /*
+ * TODO: As a concession to the future, we're ready to handle being
+ * called both early and late (i.e. after bus_add_device). Once all
+ * the platform bus code is reworked to call us late and the notifier
+ * junk above goes away, move the body of do_iommu_attach here.
+ */
+ group = iommu_group_get(dev);
+ if (group) {
+ do_iommu_attach(dev, ops, dma_base, size);
+ iommu_group_put(group);
+ } else {
+ queue_iommu_attach(dev, ops, dma_base, size);
+ }
+}
+
+void arch_teardown_dma_ops(struct device *dev)
+{
+ struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+
+ if (domain) {
+ iommu_detach_device(domain, dev);
+ if (domain->type & __IOMMU_DOMAIN_FAKE_DEFAULT)
+ iommu_domain_free(domain);
+ }
+
+ dev->archdata.dma_ops = NULL;
+}
+
+#else
+
+static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+ struct iommu_ops *iommu)
+{ }
+
+#endif /* CONFIG_IOMMU_DMA */
+
+void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+ struct iommu_ops *iommu, bool coherent)
+{
+ if (!acpi_disabled && !dev->archdata.dma_ops)
+ dev->archdata.dma_ops = dma_ops;
+
+ dev->archdata.dma_coherent = coherent;
+ __iommu_setup_dma_ops(dev, dma_base, size, iommu);
+}
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 1ae4e54..9107b6e 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -48,6 +48,13 @@ config OF_IOMMU
def_bool y
depends on OF && IOMMU_API
+# IOMMU-agnostic DMA-mapping layer
+config IOMMU_DMA
+ bool
+ depends on NEED_SG_DMA_LENGTH
+ select IOMMU_API
+ select IOMMU_IOVA
+
config FSL_PAMU
bool "Freescale IOMMU support"
depends on PPC32
diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile
index 080ffab..574b241 100644
--- a/drivers/iommu/Makefile
+++ b/drivers/iommu/Makefile
@@ -1,6 +1,7 @@
obj-$(CONFIG_IOMMU_API) += iommu.o
obj-$(CONFIG_IOMMU_API) += iommu-traces.o
obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o
+obj-$(CONFIG_IOMMU_DMA) += dma-iommu.o
obj-$(CONFIG_IOMMU_IO_PGTABLE) += io-pgtable.o
obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE) += io-pgtable-arm.o
obj-$(CONFIG_IOMMU_IOVA) += iova.o
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
new file mode 100644
index 0000000..3a20db4
--- /dev/null
+++ b/drivers/iommu/dma-iommu.c
@@ -0,0 +1,524 @@
+/*
+ * A fairly generic DMA-API to IOMMU-API glue layer.
+ *
+ * Copyright (C) 2014-2015 ARM Ltd.
+ *
+ * based in part on arch/arm/mm/dma-mapping.c:
+ * Copyright (C) 2000-2004 Russell King
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/device.h>
+#include <linux/dma-iommu.h>
+#include <linux/huge_mm.h>
+#include <linux/iommu.h>
+#include <linux/iova.h>
+#include <linux/mm.h>
+
+int iommu_dma_init(void)
+{
+ return iova_cache_get();
+}
+
+/**
+ * iommu_get_dma_cookie - Acquire DMA-API resources for a domain
+ * @domain: IOMMU domain to prepare for DMA-API usage
+ *
+ * IOMMU drivers should normally call this from their domain_alloc
+ * callback when domain->type == IOMMU_DOMAIN_DMA.
+ */
+int iommu_get_dma_cookie(struct iommu_domain *domain)
+{
+ struct iova_domain *iovad;
+
+ if (domain->iova_cookie)
+ return -EEXIST;
+
+ iovad = kzalloc(sizeof(*iovad), GFP_KERNEL);
+ domain->iova_cookie = iovad;
+
+ return iovad ? 0 : -ENOMEM;
+}
+EXPORT_SYMBOL(iommu_get_dma_cookie);
+
+/**
+ * iommu_put_dma_cookie - Release a domain's DMA mapping resources
+ * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
+ *
+ * IOMMU drivers should normally call this from their domain_free callback.
+ */
+void iommu_put_dma_cookie(struct iommu_domain *domain)
+{
+ struct iova_domain *iovad = domain->iova_cookie;
+
+ if (!iovad)
+ return;
+
+ put_iova_domain(iovad);
+ kfree(iovad);
+ domain->iova_cookie = NULL;
+}
+EXPORT_SYMBOL(iommu_put_dma_cookie);
+
+/**
+ * iommu_dma_init_domain - Initialise a DMA mapping domain
+ * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie()
+ * @base: IOVA at which the mappable address space starts
+ * @size: Size of IOVA space
+ *
+ * @base and @size should be exact multiples of IOMMU page granularity to
+ * avoid rounding surprises. If necessary, we reserve the page at address 0
+ * to ensure it is an invalid IOVA. It is safe to reinitialise a domain, but
+ * any change which could make prior IOVAs invalid will fail.
+ */
+int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size)
+{
+ struct iova_domain *iovad = domain->iova_cookie;
+ unsigned long order, base_pfn, end_pfn;
+
+ if (!iovad)
+ return -ENODEV;
+
+ /* Use the smallest supported page size for IOVA granularity */
+ order = __ffs(domain->ops->pgsize_bitmap);
+ base_pfn = max_t(unsigned long, 1, base >> order);
+ end_pfn = (base + size - 1) >> order;
+
+ /* Check the domain allows at least some access to the device... */
+ if (domain->geometry.force_aperture) {
+ if (base > domain->geometry.aperture_end ||
+ base + size <= domain->geometry.aperture_start) {
+ pr_warn("specified DMA range outside IOMMU capability\n");
+ return -EFAULT;
+ }
+ /* ...then finally give it a kicking to make sure it fits */
+ base_pfn = max_t(unsigned long, base_pfn,
+ domain->geometry.aperture_start >> order);
+ end_pfn = min_t(unsigned long, end_pfn,
+ domain->geometry.aperture_end >> order);
+ }
+
+ /* All we can safely do with an existing domain is enlarge it */
+ if (iovad->start_pfn) {
+ if (1UL << order != iovad->granule ||
+ base_pfn != iovad->start_pfn ||
+ end_pfn < iovad->dma_32bit_pfn) {
+ pr_warn("Incompatible range for DMA domain\n");
+ return -EFAULT;
+ }
+ iovad->dma_32bit_pfn = end_pfn;
+ } else {
+ init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn);
+ }
+ return 0;
+}
+EXPORT_SYMBOL(iommu_dma_init_domain);
+
+/**
+ * dma_direction_to_prot - Translate DMA API directions to IOMMU API page flags
+ * @dir: Direction of DMA transfer
+ * @coherent: Is the DMA master cache-coherent?
+ *
+ * Return: corresponding IOMMU API page protection flags
+ */
+int dma_direction_to_prot(enum dma_data_direction dir, bool coherent)
+{
+ int prot = coherent ? IOMMU_CACHE : 0;
+
+ switch (dir) {
+ case DMA_BIDIRECTIONAL:
+ return prot | IOMMU_READ | IOMMU_WRITE;
+ case DMA_TO_DEVICE:
+ return prot | IOMMU_READ;
+ case DMA_FROM_DEVICE:
+ return prot | IOMMU_WRITE;
+ default:
+ return 0;
+ }
+}
+
+static struct iova *__alloc_iova(struct iova_domain *iovad, size_t size,
+ dma_addr_t dma_limit)
+{
+ unsigned long shift = iova_shift(iovad);
+ unsigned long length = iova_align(iovad, size) >> shift;
+
+ /*
+ * Enforce size-alignment to be safe - there could perhaps be an
+ * attribute to control this per-device, or at least per-domain...
+ */
+ return alloc_iova(iovad, length, dma_limit >> shift, true);
+}
+
+/* The IOVA allocator knows what we mapped, so just unmap whatever that was */
+static void __iommu_dma_unmap(struct iommu_domain *domain, dma_addr_t dma_addr)
+{
+ struct iova_domain *iovad = domain->iova_cookie;
+ unsigned long shift = iova_shift(iovad);
+ unsigned long pfn = dma_addr >> shift;
+ struct iova *iova = find_iova(iovad, pfn);
+ size_t size;
+
+ if (WARN_ON(!iova))
+ return;
+
+ size = iova_size(iova) << shift;
+ size -= iommu_unmap(domain, pfn << shift, size);
+ /* ...and if we can't, then something is horribly, horribly wrong */
+ WARN_ON(size > 0);
+ __free_iova(iovad, iova);
+}
+
+static void __iommu_dma_free_pages(struct page **pages, int count)
+{
+ while (count--)
+ __free_page(pages[count]);
+ kvfree(pages);
+}
+
+static struct page **__iommu_dma_alloc_pages(unsigned int count, gfp_t gfp)
+{
+ struct page **pages;
+ unsigned int i = 0, array_size = count * sizeof(*pages);
+
+ if (array_size <= PAGE_SIZE)
+ pages = kzalloc(array_size, GFP_KERNEL);
+ else
+ pages = vzalloc(array_size);
+ if (!pages)
+ return NULL;
+
+ /* IOMMU can map any pages, so himem can also be used here */
+ gfp |= __GFP_NOWARN | __GFP_HIGHMEM;
+
+ while (count) {
+ struct page *page = NULL;
+ int j, order = __fls(count);
+
+ /*
+ * Higher-order allocations are a convenience rather
+ * than a necessity, hence using __GFP_NORETRY until
+ * falling back to single-page allocations.
+ */
+ for (order = min(order, MAX_ORDER); order > 0; order--) {
+ page = alloc_pages(gfp | __GFP_NORETRY, order);
+ if (!page)
+ continue;
+ if (PageCompound(page)) {
+ if (!split_huge_page(page))
+ break;
+ __free_pages(page, order);
+ } else {
+ split_page(page, order);
+ break;
+ }
+ }
+ if (!page)
+ page = alloc_page(gfp);
+ if (!page) {
+ __iommu_dma_free_pages(pages, i);
+ return NULL;
+ }
+ j = 1 << order;
+ count -= j;
+ while (j--)
+ pages[i++] = page++;
+ }
+ return pages;
+}
+
+/**
+ * iommu_dma_free - Free a buffer allocated by iommu_dma_alloc()
+ * @dev: Device which owns this buffer
+ * @pages: Array of buffer pages as returned by iommu_dma_alloc()
+ * @size: Size of buffer in bytes
+ * @handle: DMA address of buffer
+ *
+ * Frees both the pages associated with the buffer, and the array
+ * describing them
+ */
+void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
+ dma_addr_t *handle)
+{
+ __iommu_dma_unmap(iommu_get_domain_for_dev(dev), *handle);
+ __iommu_dma_free_pages(pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
+ *handle = DMA_ERROR_CODE;
+}
+
+/**
+ * iommu_dma_alloc - Allocate and map a buffer contiguous in IOVA space
+ * @dev: Device to allocate memory for. Must be a real device
+ * attached to an iommu_dma_domain
+ * @size: Size of buffer in bytes
+ * @gfp: Allocation flags
+ * @prot: IOMMU mapping flags
+ * @handle: Out argument for allocated DMA handle
+ * @flush_page: Arch callback which must ensure PAGE_SIZE bytes from the
+ * given VA/PA are visible to the given non-coherent device.
+ *
+ * If @size is less than PAGE_SIZE, then a full CPU page will be allocated,
+ * but an IOMMU which supports smaller pages might not map the whole thing.
+ *
+ * Return: Array of struct page pointers describing the buffer,
+ * or NULL on failure.
+ */
+struct page **iommu_dma_alloc(struct device *dev, size_t size,
+ gfp_t gfp, int prot, dma_addr_t *handle,
+ void (*flush_page)(struct device *, const void *, phys_addr_t))
+{
+ struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+ struct iova_domain *iovad = domain->iova_cookie;
+ struct iova *iova;
+ struct page **pages;
+ struct sg_table sgt;
+ dma_addr_t dma_addr;
+ unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+ *handle = DMA_ERROR_CODE;
+
+ pages = __iommu_dma_alloc_pages(count, gfp);
+ if (!pages)
+ return NULL;
+
+ iova = __alloc_iova(iovad, size, dev->coherent_dma_mask);
+ if (!iova)
+ goto out_free_pages;
+
+ size = iova_align(iovad, size);
+ if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL))
+ goto out_free_iova;
+
+ if (!(prot & IOMMU_CACHE)) {
+ struct sg_mapping_iter miter;
+ /*
+ * The CPU-centric flushing implied by SG_MITER_TO_SG isn't
+ * sufficient here, so skip it by using the "wrong" direction.
+ */
+ sg_miter_start(&miter, sgt.sgl, sgt.orig_nents, SG_MITER_FROM_SG);
+ while (sg_miter_next(&miter))
+ flush_page(dev, miter.addr, page_to_phys(miter.page));
+ sg_miter_stop(&miter);
+ }
+
+ dma_addr = iova_dma_addr(iovad, iova);
+ if (iommu_map_sg(domain, dma_addr, sgt.sgl, sgt.orig_nents, prot)
+ < size)
+ goto out_free_sg;
+
+ *handle = dma_addr;
+ sg_free_table(&sgt);
+ return pages;
+
+out_free_sg:
+ sg_free_table(&sgt);
+out_free_iova:
+ __free_iova(iovad, iova);
+out_free_pages:
+ __iommu_dma_free_pages(pages, count);
+ return NULL;
+}
+
+/**
+ * iommu_dma_mmap - Map a buffer into provided user VMA
+ * @pages: Array representing buffer from iommu_dma_alloc()
+ * @size: Size of buffer in bytes
+ * @vma: VMA describing requested userspace mapping
+ *
+ * Maps the pages of the buffer in @pages into @vma. The caller is responsible
+ * for verifying the correct size and protection of @vma beforehand.
+ */
+
+int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma)
+{
+ unsigned long uaddr = vma->vm_start;
+ unsigned int i, count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ int ret = -ENXIO;
+
+ for (i = vma->vm_pgoff; i < count && uaddr < vma->vm_end; i++) {
+ ret = vm_insert_page(vma, uaddr, pages[i]);
+ if (ret)
+ break;
+ uaddr += PAGE_SIZE;
+ }
+ return ret;
+}
+
+dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size, int prot)
+{
+ dma_addr_t dma_addr;
+ struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+ struct iova_domain *iovad = domain->iova_cookie;
+ phys_addr_t phys = page_to_phys(page) + offset;
+ size_t iova_off = iova_offset(iovad, phys);
+ size_t len = iova_align(iovad, size + iova_off);
+ struct iova *iova = __alloc_iova(iovad, len, dma_get_mask(dev));
+
+ if (!iova)
+ return DMA_ERROR_CODE;
+
+ dma_addr = iova_dma_addr(iovad, iova);
+ if (iommu_map(domain, dma_addr, phys - iova_off, len, prot)) {
+ __free_iova(iovad, iova);
+ return DMA_ERROR_CODE;
+ }
+ return dma_addr + iova_off;
+}
+
+void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+ __iommu_dma_unmap(iommu_get_domain_for_dev(dev), handle);
+}
+
+/*
+ * Prepare a successfully-mapped scatterlist to give back to the caller.
+ * Handling IOVA concatenation can come later, if needed
+ */
+static int __finalise_sg(struct device *dev, struct scatterlist *sg, int nents,
+ dma_addr_t dma_addr)
+{
+ struct scatterlist *s;
+ int i;
+
+ for_each_sg(sg, s, nents, i) {
+ /* Un-swizzling the fields here, hence the naming mismatch */
+ unsigned int s_offset = sg_dma_address(s);
+ unsigned int s_length = sg_dma_len(s);
+ unsigned int s_dma_len = s->length;
+
+ s->offset = s_offset;
+ s->length = s_length;
+ sg_dma_address(s) = dma_addr + s_offset;
+ dma_addr += s_dma_len;
+ }
+ return i;
+}
+
+/*
+ * If mapping failed, then just restore the original list,
+ * but making sure the DMA fields are invalidated.
+ */
+static void __invalidate_sg(struct scatterlist *sg, int nents)
+{
+ struct scatterlist *s;
+ int i;
+
+ for_each_sg(sg, s, nents, i) {
+ if (sg_dma_address(s) != DMA_ERROR_CODE)
+ s->offset = sg_dma_address(s);
+ if (sg_dma_len(s))
+ s->length = sg_dma_len(s);
+ sg_dma_address(s) = DMA_ERROR_CODE;
+ sg_dma_len(s) = 0;
+ }
+}
+
+/*
+ * The DMA API client is passing in a scatterlist which could describe
+ * any old buffer layout, but the IOMMU API requires everything to be
+ * aligned to IOMMU pages. Hence the need for this complicated bit of
+ * impedance-matching, to be able to hand off a suitably-aligned list,
+ * but still preserve the original offsets and sizes for the caller.
+ */
+int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
+ int nents, int prot)
+{
+ struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+ struct iova_domain *iovad = domain->iova_cookie;
+ struct iova *iova;
+ struct scatterlist *s, *prev = NULL;
+ dma_addr_t dma_addr;
+ size_t iova_len = 0;
+ int i;
+
+ /*
+ * Work out how much IOVA space we need, and align the segments to
+ * IOVA granules for the IOMMU driver to handle. With some clever
+ * trickery we can modify the list in-place, but reversibly, by
+ * hiding the original data in the as-yet-unused DMA fields.
+ */
+ for_each_sg(sg, s, nents, i) {
+ size_t s_offset = iova_offset(iovad, s->offset);
+ size_t s_length = s->length;
+
+ sg_dma_address(s) = s->offset;
+ sg_dma_len(s) = s_length;
+ s->offset -= s_offset;
+ s_length = iova_align(iovad, s_length + s_offset);
+ s->length = s_length;
+
+ /*
+ * The simple way to avoid the rare case of a segment
+ * crossing the boundary mask is to pad the previous one
+ * to end at a naturally-aligned IOVA for this one's size,
+ * at the cost of potentially over-allocating a little.
+ */
+ if (prev) {
+ size_t pad_len = roundup_pow_of_two(s_length);
+
+ pad_len = (pad_len - iova_len) & (pad_len - 1);
+ prev->length += pad_len;
+ iova_len += pad_len;
+ }
+
+ iova_len += s_length;
+ prev = s;
+ }
+
+ iova = __alloc_iova(iovad, iova_len, dma_get_mask(dev));
+ if (!iova)
+ goto out_restore_sg;
+
+ /*
+ * We'll leave any physical concatenation to the IOMMU driver's
+ * implementation - it knows better than we do.
+ */
+ dma_addr = iova_dma_addr(iovad, iova);
+ if (iommu_map_sg(domain, dma_addr, sg, nents, prot) < iova_len)
+ goto out_free_iova;
+
+ return __finalise_sg(dev, sg, nents, dma_addr);
+
+out_free_iova:
+ __free_iova(iovad, iova);
+out_restore_sg:
+ __invalidate_sg(sg, nents);
+ return 0;
+}
+
+void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+ /*
+ * The scatterlist segments are mapped into a single
+ * contiguous IOVA allocation, so this is incredibly easy.
+ */
+ __iommu_dma_unmap(iommu_get_domain_for_dev(dev), sg_dma_address(sg));
+}
+
+int iommu_dma_supported(struct device *dev, u64 mask)
+{
+ /*
+ * 'Special' IOMMUs which don't have the same addressing capability
+ * as the CPU will have to wait until we have some way to query that
+ * before they'll be able to use this framework.
+ */
+ return 1;
+}
+
+int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+ return dma_addr == DMA_ERROR_CODE;
+}
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
new file mode 100644
index 0000000..fc48103
--- /dev/null
+++ b/include/linux/dma-iommu.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2014-2015 ARM Ltd.
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef __DMA_IOMMU_H
+#define __DMA_IOMMU_H
+
+#ifdef __KERNEL__
+#include <asm/errno.h>
+
+#ifdef CONFIG_IOMMU_DMA
+#include <linux/iommu.h>
+
+int iommu_dma_init(void);
+
+/* Domain management interface for IOMMU drivers */
+int iommu_get_dma_cookie(struct iommu_domain *domain);
+void iommu_put_dma_cookie(struct iommu_domain *domain);
+
+/* Setup call for arch DMA mapping code */
+int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size);
+
+/* General helpers for DMA-API <-> IOMMU-API interaction */
+int dma_direction_to_prot(enum dma_data_direction dir, bool coherent);
+
+/*
+ * These implement the bulk of the relevant DMA mapping callbacks, but require
+ * the arch code to take care of attributes and cache maintenance
+ */
+struct page **iommu_dma_alloc(struct device *dev, size_t size,
+ gfp_t gfp, int prot, dma_addr_t *handle,
+ void (*flush_page)(struct device *, const void *, phys_addr_t));
+void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
+ dma_addr_t *handle);
+
+int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma);
+
+dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size, int prot);
+int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
+ int nents, int prot);
+
+/*
+ * Arch code with no special attribute handling may use these
+ * directly as DMA mapping callbacks for simplicity
+ */
+void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
+ enum dma_data_direction dir, struct dma_attrs *attrs);
+void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
+ enum dma_data_direction dir, struct dma_attrs *attrs);
+int iommu_dma_supported(struct device *dev, u64 mask);
+int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
+
+#else
+
+struct iommu_domain;
+
+static inline int iommu_dma_init(void)
+{
+ return 0;
+}
+
+static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
+{
+ return -ENODEV;
+}
+
+static inline void iommu_put_dma_cookie(struct iommu_domain *domain)
+{
+}
+
+#endif /* CONFIG_IOMMU_DMA */
+#endif /* __KERNEL__ */
+#endif /* __DMA_IOMMU_H */
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 0546b87..98eb66c 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -81,6 +81,7 @@ struct iommu_domain {
iommu_fault_handler_t handler;
void *handler_token;
struct iommu_domain_geometry geometry;
+ void *iova_cookie;
};
enum iommu_cap {