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);
+ }
+}
+
+#else
+
+static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+ struct iommu_ops *iommu)
+{ }
+
+#endif /* CONFIG_IOMMU_DMA */
+
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff