This patch moves all the IOMMU-based DMA-mapping code from arch/arm64/mm to drivers/iommu/dma-iommu-ops.c. This way it can be easily shared with ARM architecture, which will also use them.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- arch/arm64/include/asm/dma-mapping.h | 39 ++- arch/arm64/mm/dma-mapping.c | 491 ++--------------------------------- drivers/iommu/Makefile | 2 +- drivers/iommu/dma-iommu-ops.c | 471 +++++++++++++++++++++++++++++++++ include/linux/dma-iommu.h | 14 + 5 files changed, 538 insertions(+), 479 deletions(-) create mode 100644 drivers/iommu/dma-iommu-ops.c
diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h index ba437f090a74..3a582d820717 100644 --- a/arch/arm64/include/asm/dma-mapping.h +++ b/arch/arm64/include/asm/dma-mapping.h @@ -22,6 +22,7 @@ #include <linux/vmalloc.h>
#include <xen/xen.h> +#include <asm/cacheflush.h> #include <asm/xen/hypervisor.h>
#define DMA_ERROR_CODE (~(dma_addr_t)0) @@ -47,14 +48,17 @@ static inline struct dma_map_ops *get_dma_ops(struct device *dev) return __generic_dma_ops(dev); }
+static inline void arch_set_dma_ops(struct device *dev, struct dma_map_ops *ops) +{ + dev->archdata.dma_ops = ops; +} + 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) @@ -86,5 +90,36 @@ static inline void dma_mark_clean(void *addr, size_t size) { }
+static inline void arch_flush_page(struct device *dev, const void *virt, + phys_addr_t phys) +{ + __dma_flush_range(virt, virt + PAGE_SIZE); +} + +static inline void arch_dma_map_area(phys_addr_t phys, size_t size, + enum dma_data_direction dir) +{ + __dma_map_area(phys_to_virt(phys), size, dir); +} + +static inline void arch_dma_unmap_area(phys_addr_t phys, size_t size, + enum dma_data_direction dir) +{ + __dma_unmap_area(phys_to_virt(phys), size, dir); +} + +static inline pgprot_t arch_get_dma_pgprot(struct dma_attrs *attrs, + pgprot_t prot, bool coherent) +{ + if (!coherent || dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs)) + return pgprot_writecombine(prot); + return prot; +} + +extern void *arch_alloc_from_atomic_pool(size_t size, struct page **ret_page, + gfp_t flags); +extern bool arch_in_atomic_pool(void *start, size_t size); +extern int arch_free_from_atomic_pool(void *start, size_t size); + #endif /* __KERNEL__ */ #endif /* __ASM_DMA_MAPPING_H */ diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c index a6e757cbab77..d8cb8552bbff 100644 --- a/arch/arm64/mm/dma-mapping.c +++ b/arch/arm64/mm/dma-mapping.c @@ -24,19 +24,12 @@ #include <linux/genalloc.h> #include <linux/dma-mapping.h> #include <linux/dma-contiguous.h> +#include <linux/dma-iommu.h> #include <linux/vmalloc.h> #include <linux/swiotlb.h>
#include <asm/cacheflush.h>
-static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot, - bool coherent) -{ - if (!coherent || dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs)) - return pgprot_writecombine(prot); - return prot; -} - static struct gen_pool *atomic_pool;
#define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K @@ -49,7 +42,7 @@ static int __init early_coherent_pool(char *p) } early_param("coherent_pool", early_coherent_pool);
-static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags) +void *arch_alloc_from_atomic_pool(size_t size, struct page **ret_page, gfp_t flags) { unsigned long val; void *ptr = NULL; @@ -71,14 +64,14 @@ static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags) return ptr; }
-static bool __in_atomic_pool(void *start, size_t size) +bool arch_in_atomic_pool(void *start, size_t size) { return addr_in_gen_pool(atomic_pool, (unsigned long)start, size); }
-static int __free_from_pool(void *start, size_t size) +int arch_free_from_atomic_pool(void *start, size_t size) { - if (!__in_atomic_pool(start, size)) + if (!arch_in_atomic_pool(start, size)) return 0;
gen_pool_free(atomic_pool, (unsigned long)start, size); @@ -142,13 +135,13 @@ static void *__dma_alloc(struct device *dev, size_t size, struct page *page; void *ptr, *coherent_ptr; bool coherent = is_device_dma_coherent(dev); - pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, false); + pgprot_t prot = arch_get_dma_pgprot(attrs, PAGE_KERNEL, false);
size = PAGE_ALIGN(size);
if (!coherent && !gfpflags_allow_blocking(flags)) { struct page *page = NULL; - void *addr = __alloc_from_pool(size, &page, flags); + void *addr = arch_alloc_from_atomic_pool(size, &page, flags);
if (addr) *dma_handle = phys_to_dma(dev, page_to_phys(page)); @@ -192,7 +185,7 @@ static void __dma_free(struct device *dev, size_t size, size = PAGE_ALIGN(size);
if (!is_device_dma_coherent(dev)) { - if (__free_from_pool(vaddr, size)) + if (arch_free_from_atomic_pool(vaddr, size)) return; vunmap(vaddr); } @@ -312,7 +305,7 @@ static int __swiotlb_mmap(struct device *dev, unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT; unsigned long off = vma->vm_pgoff;
- vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot, + vma->vm_page_prot = arch_get_dma_pgprot(attrs, vma->vm_page_prot, is_device_dma_coherent(dev));
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) @@ -526,470 +519,16 @@ static int __init dma_debug_do_init(void) } 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); - size_t iosize = size; - void *addr; - - if (WARN(!dev, "cannot create IOMMU mapping for unknown device\n")) - return NULL; - - size = PAGE_ALIGN(size); - - /* - * 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 (gfpflags_allow_blocking(gfp)) { - struct page **pages; - pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, coherent); - - pages = iommu_dma_alloc(dev, iosize, 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, iosize, 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, iosize, 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) -{ - size_t iosize = size; - - size = PAGE_ALIGN(size); - /* - * @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, iosize, 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, iosize, &handle); - dma_common_free_remap(cpu_addr, size, VM_USERMAP); - } else { - iommu_dma_unmap_page(dev, handle, iosize, 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 __init 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); - - /* handle devices queued before this arch_initcall */ - if (!ret) - __iommu_attach_notifier(NULL, BUS_NOTIFY_ADD_DEVICE, NULL); - 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) +void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + struct iommu_ops *iommu, bool coherent) { - struct iommu_group *group; + dev->archdata.dma_coherent = coherent;
- 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); - } + if (!common_iommu_setup_dma_ops(dev, dma_base, size, iommu)) + arch_set_dma_ops(dev, &swiotlb_dma_ops); }
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 (!dev->archdata.dma_ops) - dev->archdata.dma_ops = &swiotlb_dma_ops; - - dev->archdata.dma_coherent = coherent; - __iommu_setup_dma_ops(dev, dma_base, size, iommu); + common_iommu_teardown_dma_ops(dev); } diff --git a/drivers/iommu/Makefile b/drivers/iommu/Makefile index 42fc0c25cf1a..c0dbf765bf45 100644 --- a/drivers/iommu/Makefile +++ b/drivers/iommu/Makefile @@ -1,7 +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-$(CONFIG_IOMMU_DMA) += dma-iommu.o dma-iommu-ops.o obj-$(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-ops.c b/drivers/iommu/dma-iommu-ops.c new file mode 100644 index 000000000000..047c47e3c0ab --- /dev/null +++ b/drivers/iommu/dma-iommu-ops.c @@ -0,0 +1,471 @@ +/* + * A common IOMMU based DMA-API implementation for ARM and ARM64 architecutes. + * + * 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/gfp.h> +#include <linux/huge_mm.h> +#include <linux/iommu.h> +#include <linux/iova.h> +#include <linux/mm.h> +#include <linux/scatterlist.h> +#include <linux/vmalloc.h> + +#include <linux/platform_device.h> +#include <linux/amba/bus.h> + +#include <asm/dma-mapping.h> + +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); + size_t iosize = size; + void *addr; + + if (WARN(!dev, "cannot create IOMMU mapping for unknown device\n")) + return NULL; + + size = PAGE_ALIGN(size); + + /* + * 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 (gfpflags_allow_blocking(gfp)) { + struct page **pages; + pgprot_t prot = arch_get_dma_pgprot(attrs, PAGE_KERNEL, + coherent); + + pages = iommu_dma_alloc(dev, iosize, gfp, ioprot, handle, + arch_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, iosize, 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 = arch_alloc_from_atomic_pool(size, &page, gfp); + } + if (!addr) + return NULL; + + *handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot); + if (iommu_dma_mapping_error(dev, *handle)) { + if (coherent) + __free_pages(page, get_order(size)); + else + arch_free_from_atomic_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) +{ + size_t iosize = size; + + size = PAGE_ALIGN(size); + /* + * @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 (arch_in_atomic_pool(cpu_addr, size)) { + iommu_dma_unmap_page(dev, handle, iosize, 0, NULL); + arch_free_from_atomic_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, iosize, &handle); + dma_common_free_remap(cpu_addr, size, VM_USERMAP); + } else { + iommu_dma_unmap_page(dev, handle, iosize, 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 = arch_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); + arch_dma_unmap_area(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); + arch_dma_map_area(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) + arch_dma_unmap_area(sg_phys(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) + arch_dma_map_area(sg_phys(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; + + arch_set_dma_ops(dev, &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 __init 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); + + /* handle devices queued before this arch_initcall */ + if (!ret) + __iommu_attach_notifier(NULL, BUS_NOTIFY_ADD_DEVICE, NULL); + return ret; +} +arch_initcall(__iommu_dma_init); + +bool common_iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + const struct iommu_ops *ops) +{ + struct iommu_group *group; + + if (!ops) + return false; + /* + * 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); + } + + return true; +} + +void common_iommu_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); + } + + arch_set_dma_ops(dev, NULL); +} diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h index fc481037478a..01a836c43dc3 100644 --- a/include/linux/dma-iommu.h +++ b/include/linux/dma-iommu.h @@ -62,6 +62,10 @@ void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents, int iommu_dma_supported(struct device *dev, u64 mask); int iommu_dma_mapping_error(struct device *dev, dma_addr_t dma_addr);
+bool common_iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, + const struct iommu_ops *ops); +void common_iommu_teardown_dma_ops(struct device *dev); + #else
struct iommu_domain; @@ -80,6 +84,16 @@ static inline void iommu_put_dma_cookie(struct iommu_domain *domain) { }
+static inline bool common_iommu_setup_dma_ops(struct device *dev, u64 dma_base, + u64 size, const struct iommu_ops *ops) +{ + return false; +} + +static inline void common_iommu_teardown_dma_ops(struct device *dev) +{ +} + #endif /* CONFIG_IOMMU_DMA */ #endif /* __KERNEL__ */ #endif /* __DMA_IOMMU_H */