[PATCH 07/21] dma-iommu: move the arm64 wrappers to common code

From: Christoph Hellwig
Date: Wed Mar 27 2019 - 04:06:53 EST

There is nothing really arm64 specific in the iommu_dma_ops
implementation, so move it to dma-iommu.c and keep a lot of symbols
self-contained. Note the implementation does depend on the
DMA_DIRECT_REMAP infrastructure for now, so we'll have to make the
DMA_IOMMU support depend on it, but this will be relaxed soon.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/arm64/mm/dma-mapping.c | 389 +-----------------------------------
drivers/iommu/Kconfig | 1 +
drivers/iommu/dma-iommu.c | 383 ++++++++++++++++++++++++++++++++---
include/linux/dma-iommu.h | 44 +---
4 files changed, 365 insertions(+), 452 deletions(-)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 54787a3d4ad9..bf49e982c978 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -27,6 +27,7 @@
#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
#include <linux/dma-contiguous.h>
+#include <linux/dma-iommu.h>
#include <linux/vmalloc.h>
#include <linux/swiotlb.h>
#include <linux/pci.h>
@@ -58,27 +59,6 @@ void arch_dma_prep_coherent(struct page *page, size_t size)
__dma_flush_area(page_address(page), size);
}

-#ifdef CONFIG_IOMMU_DMA
-static int __swiotlb_get_sgtable_page(struct sg_table *sgt,
- struct page *page, size_t size)
-{
- int ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
-
- if (!ret)
- sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
-
- return ret;
-}
-
-static int __swiotlb_mmap_pfn(struct vm_area_struct *vma,
- unsigned long pfn, size_t size)
-{
- return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
- vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
-}
-#endif /* CONFIG_IOMMU_DMA */
-
static int __init arm64_dma_init(void)
{
WARN_TAINT(ARCH_DMA_MINALIGN < cache_line_size(),
@@ -90,379 +70,18 @@ static int __init arm64_dma_init(void)
arch_initcall(arm64_dma_init);

#ifdef CONFIG_IOMMU_DMA
-#include <linux/dma-iommu.h>
-#include <linux/platform_device.h>
-#include <linux/amba/bus.h>
-
-static void *__iommu_alloc_attrs(struct device *dev, size_t size,
- dma_addr_t *handle, gfp_t gfp,
- unsigned long attrs)
-{
- bool coherent = dev_is_dma_coherent(dev);
- int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
- 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 *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 = dma_alloc_from_pool(size, &page, gfp);
- }
- if (!addr)
- return NULL;
-
- *handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot);
- if (*handle == DMA_MAPPING_ERROR) {
- if (coherent)
- __free_pages(page, get_order(size));
- else
- dma_free_from_pool(addr, size);
- addr = NULL;
- }
- } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
- pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
- struct page *page;
-
- page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
- get_order(size), gfp & __GFP_NOWARN);
- if (!page)
- return NULL;
-
- *handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot);
- if (*handle == DMA_MAPPING_ERROR) {
- dma_release_from_contiguous(dev, page,
- size >> PAGE_SHIFT);
- return NULL;
- }
- addr = dma_common_contiguous_remap(page, size, VM_USERMAP,
- prot,
- __builtin_return_address(0));
- if (addr) {
- if (!coherent)
- __dma_flush_area(page_to_virt(page), iosize);
- memset(addr, 0, size);
- } else {
- iommu_dma_unmap_page(dev, *handle, iosize, 0, attrs);
- dma_release_from_contiguous(dev, page,
- size >> PAGE_SHIFT);
- }
- } else {
- pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
- struct page **pages;
-
- pages = iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot,
- handle);
- 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);
- }
- return addr;
-}
-
-static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
- dma_addr_t handle, unsigned long attrs)
-{
- size_t iosize = size;
-
- size = PAGE_ALIGN(size);
- /*
- * @cpu_addr will be one of 4 things depending on how it was allocated:
- * - A remapped array of pages for contiguous allocations.
- * - 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 (dma_in_atomic_pool(cpu_addr, size)) {
- iommu_dma_unmap_page(dev, handle, iosize, 0, 0);
- dma_free_from_pool(cpu_addr, size);
- } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
- struct page *page = vmalloc_to_page(cpu_addr);
-
- iommu_dma_unmap_page(dev, handle, iosize, 0, attrs);
- dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
- dma_common_free_remap(cpu_addr, size, VM_USERMAP);
- } 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, 0);
- __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,
- unsigned long attrs)
-{
- unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
- unsigned long off = vma->vm_pgoff;
- struct vm_struct *area;
- int ret;
-
- vma->vm_page_prot = arch_dma_mmap_pgprot(dev, vma->vm_page_prot, attrs);
-
- if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
- return ret;
-
- if (off >= nr_pages || vma_pages(vma) > nr_pages - off)
- return -ENXIO;
-
- if (!is_vmalloc_addr(cpu_addr)) {
- unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
- return __swiotlb_mmap_pfn(vma, pfn, size);
- }
-
- if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
- /*
- * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
- * hence in the vmalloc space.
- */
- unsigned long pfn = vmalloc_to_pfn(cpu_addr);
- return __swiotlb_mmap_pfn(vma, pfn, size);
- }
-
- 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, unsigned long attrs)
-{
- unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
- struct vm_struct *area = find_vm_area(cpu_addr);
-
- if (!is_vmalloc_addr(cpu_addr)) {
- struct page *page = virt_to_page(cpu_addr);
- return __swiotlb_get_sgtable_page(sgt, page, size);
- }
-
- if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
- /*
- * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
- * hence in the vmalloc space.
- */
- struct page *page = vmalloc_to_page(cpu_addr);
- return __swiotlb_get_sgtable_page(sgt, page, size);
- }
-
- 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 (dev_is_dma_coherent(dev))
- return;
-
- phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dev_addr);
- arch_sync_dma_for_cpu(dev, 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 (dev_is_dma_coherent(dev))
- return;
-
- phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dev_addr);
- arch_sync_dma_for_device(dev, 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,
- unsigned long attrs)
-{
- bool coherent = dev_is_dma_coherent(dev);
- int prot = dma_info_to_prot(dir, coherent, attrs);
- dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);
-
- if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
- dev_addr != DMA_MAPPING_ERROR)
- __dma_map_area(page_address(page) + offset, 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,
- unsigned long attrs)
-{
- if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
- __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 (dev_is_dma_coherent(dev))
- return;
-
- for_each_sg(sgl, sg, nelems, i)
- arch_sync_dma_for_cpu(dev, 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 (dev_is_dma_coherent(dev))
- return;
-
- for_each_sg(sgl, sg, nelems, i)
- arch_sync_dma_for_device(dev, 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,
- unsigned long attrs)
-{
- bool coherent = dev_is_dma_coherent(dev);
-
- if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
- __iommu_sync_sg_for_device(dev, sgl, nelems, dir);
-
- return iommu_dma_map_sg(dev, sgl, nelems,
- dma_info_to_prot(dir, coherent, attrs));
-}
-
-static void __iommu_unmap_sg_attrs(struct device *dev,
- struct scatterlist *sgl, int nelems,
- enum dma_data_direction dir,
- unsigned long attrs)
-{
- if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
- __iommu_sync_sg_for_cpu(dev, sgl, nelems, dir);
-
- iommu_dma_unmap_sg(dev, sgl, nelems, dir, attrs);
-}
-
-static const 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,
- .map_resource = iommu_dma_map_resource,
- .unmap_resource = iommu_dma_unmap_resource,
-};
-
-static int __init __iommu_dma_init(void)
-{
- return iommu_dma_init();
-}
-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_domain *domain;
-
- if (!ops)
- return;
-
- /*
- * The IOMMU core code allocates the default DMA domain, which the
- * underlying IOMMU driver needs to support via the dma-iommu layer.
- */
- domain = iommu_get_domain_for_dev(dev);
-
- if (!domain)
- goto out_err;
-
- if (domain->type == IOMMU_DOMAIN_DMA) {
- if (iommu_dma_init_domain(domain, dma_base, size, dev))
- goto out_err;
-
- dev->dma_ops = &iommu_dma_ops;
- }
-
- return;
-
-out_err:
- pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
- dev_name(dev));
-}
-
void arch_teardown_dma_ops(struct device *dev)
{
dev->dma_ops = NULL;
}
-
-#else
-
-static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
- const struct iommu_ops *iommu)
-{ }
-
-#endif /* CONFIG_IOMMU_DMA */
+#endif

void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
const struct iommu_ops *iommu, bool coherent)
{
dev->dma_coherent = coherent;
- __iommu_setup_dma_ops(dev, dma_base, size, iommu);
+ if (iommu)
+ iommu_setup_dma_ops(dev, dma_base, size, iommu);

#ifdef CONFIG_XEN
if (xen_initial_domain())
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index 6f07f3b21816..bdc14baf2ee5 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -95,6 +95,7 @@ config IOMMU_DMA
select IOMMU_API
select IOMMU_IOVA
select NEED_SG_DMA_LENGTH
+ depends on DMA_DIRECT_REMAP

config FSL_PAMU
bool "Freescale IOMMU support"
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index f915cb7c46e6..d14fe9f8c692 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -21,6 +21,7 @@

#include <linux/acpi_iort.h>
#include <linux/device.h>
+#include <linux/dma-contiguous.h>
#include <linux/dma-iommu.h>
#include <linux/dma-noncoherent.h>
#include <linux/gfp.h>
@@ -79,11 +80,6 @@ static struct iommu_dma_cookie *cookie_alloc(enum iommu_dma_cookie_type type)
return cookie;
}

-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
@@ -285,7 +281,7 @@ static void iommu_dma_flush_iotlb_all(struct iova_domain *iovad)
* 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,
+static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
u64 size, struct device *dev)
{
struct iommu_dma_cookie *cookie = domain->iova_cookie;
@@ -336,7 +332,6 @@ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,

return iova_reserve_iommu_regions(dev, domain);
}
-EXPORT_SYMBOL(iommu_dma_init_domain);

/**
* dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API
@@ -347,7 +342,7 @@ EXPORT_SYMBOL(iommu_dma_init_domain);
*
* Return: corresponding IOMMU API page protection flags
*/
-int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
+static int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
unsigned long attrs)
{
int prot = coherent ? IOMMU_CACHE : 0;
@@ -506,17 +501,17 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev,
}

/**
- * iommu_dma_free - Free a buffer allocated by iommu_dma_alloc()
+ * 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()
+ * @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)
+static void __iommu_dma_free(struct device *dev, struct page **pages,
+ size_t size, dma_addr_t *handle)
{
__iommu_dma_unmap(iommu_get_dma_domain(dev), *handle, size);
__iommu_dma_free_pages(pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
@@ -524,7 +519,7 @@ void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
}

/**
- * iommu_dma_alloc - Allocate and map a buffer contiguous in IOVA space
+ * __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
@@ -539,8 +534,8 @@ void iommu_dma_free(struct device *dev, struct page **pages, size_t size,
* 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,
- unsigned long attrs, int prot, dma_addr_t *handle)
+static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
+ gfp_t gfp, unsigned long attrs, int prot, dma_addr_t *handle)
{
struct iommu_domain *domain = iommu_get_dma_domain(dev);
struct iommu_dma_cookie *cookie = domain->iova_cookie;
@@ -602,16 +597,16 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
}

/**
- * iommu_dma_mmap - Map a buffer into provided user VMA
- * @pages: Array representing buffer from iommu_dma_alloc()
+ * __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)
+static 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;
@@ -626,6 +621,58 @@ int iommu_dma_mmap(struct page **pages, size_t size, struct vm_area_struct *vma)
return ret;
}

+static void iommu_dma_sync_single_for_cpu(struct device *dev,
+ dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)
+{
+ phys_addr_t phys;
+
+ if (dev_is_dma_coherent(dev))
+ return;
+
+ phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dma_handle);
+ arch_sync_dma_for_cpu(dev, phys, size, dir);
+}
+
+static void iommu_dma_sync_single_for_device(struct device *dev,
+ dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)
+{
+ phys_addr_t phys;
+
+ if (dev_is_dma_coherent(dev))
+ return;
+
+ phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dma_handle);
+ arch_sync_dma_for_device(dev, phys, size, dir);
+}
+
+static void iommu_dma_sync_sg_for_cpu(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir)
+{
+ struct scatterlist *sg;
+ int i;
+
+ if (dev_is_dma_coherent(dev))
+ return;
+
+ for_each_sg(sgl, sg, nelems, i)
+ arch_sync_dma_for_cpu(dev, sg_phys(sg), sg->length, dir);
+}
+
+static void iommu_dma_sync_sg_for_device(struct device *dev,
+ struct scatterlist *sgl, int nelems,
+ enum dma_data_direction dir)
+{
+ struct scatterlist *sg;
+ int i;
+
+ if (dev_is_dma_coherent(dev))
+ return;
+
+ for_each_sg(sgl, sg, nelems, i)
+ arch_sync_dma_for_device(dev, sg_phys(sg), sg->length, dir);
+}
+
static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
size_t size, int prot, struct iommu_domain *domain)
{
@@ -649,19 +696,44 @@ static dma_addr_t __iommu_dma_map(struct device *dev, phys_addr_t phys,
return iova + iova_off;
}

-dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
+static dma_addr_t __iommu_dma_map_page(struct device *dev, struct page *page,
unsigned long offset, size_t size, int prot)
{
return __iommu_dma_map(dev, page_to_phys(page) + offset, size, prot,
iommu_get_dma_domain(dev));
}

-void iommu_dma_unmap_page(struct device *dev, dma_addr_t handle, size_t size,
- enum dma_data_direction dir, unsigned long attrs)
+static void __iommu_dma_unmap_page(struct device *dev, dma_addr_t handle,
+ size_t size, enum dma_data_direction dir, unsigned long attrs)
{
__iommu_dma_unmap(iommu_get_dma_domain(dev), handle, size);
}

+static dma_addr_t iommu_dma_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+ phys_addr_t phys = page_to_phys(page) + offset;
+ bool coherent = dev_is_dma_coherent(dev);
+ dma_addr_t dma_handle;
+
+ dma_handle =__iommu_dma_map(dev, phys, size,
+ dma_info_to_prot(dir, coherent, attrs),
+ iommu_get_dma_domain(dev));
+ if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
+ dma_handle != DMA_MAPPING_ERROR)
+ arch_sync_dma_for_device(dev, phys, size, dir);
+ return dma_handle;
+}
+
+static void iommu_dma_unmap_page(struct device *dev, dma_addr_t dma_handle,
+ size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ iommu_dma_sync_single_for_cpu(dev, dma_handle, size, dir);
+ __iommu_dma_unmap(iommu_get_domain_for_dev(dev), dma_handle, size);
+}
+
/*
* Prepare a successfully-mapped scatterlist to give back to the caller.
*
@@ -744,18 +816,22 @@ static void __invalidate_sg(struct scatterlist *sg, int nents)
* 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)
+static int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
+ int nents, enum dma_data_direction dir, unsigned long attrs)
{
struct iommu_domain *domain = iommu_get_dma_domain(dev);
struct iommu_dma_cookie *cookie = domain->iova_cookie;
struct iova_domain *iovad = &cookie->iovad;
struct scatterlist *s, *prev = NULL;
+ int prot = dma_info_to_prot(dir, dev_is_dma_coherent(dev), attrs);
dma_addr_t iova;
size_t iova_len = 0;
unsigned long mask = dma_get_seg_boundary(dev);
int i;

+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
+ iommu_dma_sync_sg_for_device(dev, sg, nents, dir);
+
/*
* Work out how much IOVA space we need, and align the segments to
* IOVA granules for the IOMMU driver to handle. With some clever
@@ -815,12 +891,16 @@ int iommu_dma_map_sg(struct device *dev, struct scatterlist *sg,
return 0;
}

-void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
- enum dma_data_direction dir, unsigned long attrs)
+static void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
+ int nents, enum dma_data_direction dir, unsigned long attrs)
{
dma_addr_t start, end;
struct scatterlist *tmp;
int i;
+
+ if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
+ iommu_dma_sync_sg_for_cpu(dev, sg, nents, dir);
+
/*
* The scatterlist segments are mapped into a single
* contiguous IOVA allocation, so this is incredibly easy.
@@ -835,7 +915,7 @@ void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
__iommu_dma_unmap(iommu_get_dma_domain(dev), start, end - start);
}

-dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
+static dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
return __iommu_dma_map(dev, phys, size,
@@ -843,12 +923,257 @@ dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
iommu_get_dma_domain(dev));
}

-void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
+static void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
size_t size, enum dma_data_direction dir, unsigned long attrs)
{
__iommu_dma_unmap(iommu_get_dma_domain(dev), handle, size);
}

+static void *iommu_dma_alloc(struct device *dev, size_t size,
+ dma_addr_t *handle, gfp_t gfp, unsigned long attrs)
+{
+ bool coherent = dev_is_dma_coherent(dev);
+ int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
+ size_t iosize = size;
+ void *addr;
+
+ 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 *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 = dma_alloc_from_pool(size, &page, gfp);
+ }
+ if (!addr)
+ return NULL;
+
+ *handle = __iommu_dma_map_page(dev, page, 0, iosize, ioprot);
+ if (*handle == DMA_MAPPING_ERROR) {
+ if (coherent)
+ __free_pages(page, get_order(size));
+ else
+ dma_free_from_pool(addr, size);
+ addr = NULL;
+ }
+ } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
+ pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
+ struct page *page;
+
+ page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
+ get_order(size), gfp & __GFP_NOWARN);
+ if (!page)
+ return NULL;
+
+ *handle = __iommu_dma_map_page(dev, page, 0, iosize, ioprot);
+ if (*handle == DMA_MAPPING_ERROR) {
+ dma_release_from_contiguous(dev, page,
+ size >> PAGE_SHIFT);
+ return NULL;
+ }
+ addr = dma_common_contiguous_remap(page, size, VM_USERMAP,
+ prot,
+ __builtin_return_address(0));
+ if (addr) {
+ if (!coherent)
+ arch_dma_prep_coherent(page, iosize);
+ memset(addr, 0, size);
+ } else {
+ __iommu_dma_unmap_page(dev, *handle, iosize, 0, attrs);
+ dma_release_from_contiguous(dev, page,
+ size >> PAGE_SHIFT);
+ }
+ } else {
+ pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
+ struct page **pages;
+
+ pages = __iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot,
+ handle);
+ 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);
+ }
+ return addr;
+}
+
+static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
+ dma_addr_t handle, unsigned long attrs)
+{
+ size_t iosize = size;
+
+ size = PAGE_ALIGN(size);
+ /*
+ * @cpu_addr will be one of 4 things depending on how it was allocated:
+ * - A remapped array of pages for contiguous allocations.
+ * - 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 (dma_in_atomic_pool(cpu_addr, size)) {
+ __iommu_dma_unmap_page(dev, handle, iosize, 0, 0);
+ dma_free_from_pool(cpu_addr, size);
+ } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
+ struct page *page = vmalloc_to_page(cpu_addr);
+
+ __iommu_dma_unmap_page(dev, handle, iosize, 0, attrs);
+ dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
+ dma_common_free_remap(cpu_addr, size, VM_USERMAP);
+ } 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, 0);
+ __free_pages(virt_to_page(cpu_addr), get_order(size));
+ }
+}
+
+static int __iommu_dma_mmap_pfn(struct vm_area_struct *vma,
+ unsigned long pfn, size_t size)
+{
+ return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
+ vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+}
+
+static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ unsigned long attrs)
+{
+ unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ unsigned long off = vma->vm_pgoff;
+ struct vm_struct *area;
+ int ret;
+
+ vma->vm_page_prot = arch_dma_mmap_pgprot(dev, vma->vm_page_prot, attrs);
+
+ if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
+ return ret;
+
+ if (off >= nr_pages || vma_pages(vma) > nr_pages - off)
+ return -ENXIO;
+
+ if (!is_vmalloc_addr(cpu_addr)) {
+ unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
+ return __iommu_dma_mmap_pfn(vma, pfn, size);
+ }
+
+ if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
+ /*
+ * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
+ * hence in the vmalloc space.
+ */
+ unsigned long pfn = vmalloc_to_pfn(cpu_addr);
+ return __iommu_dma_mmap_pfn(vma, pfn, size);
+ }
+
+ 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_dma_get_sgtable_page(struct sg_table *sgt, struct page *page,
+ size_t size)
+{
+ int ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
+
+ if (!ret)
+ sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
+ return ret;
+}
+
+static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ unsigned long attrs)
+{
+ unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ struct vm_struct *area = find_vm_area(cpu_addr);
+
+ if (!is_vmalloc_addr(cpu_addr)) {
+ struct page *page = virt_to_page(cpu_addr);
+ return __iommu_dma_get_sgtable_page(sgt, page, size);
+ }
+
+ if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
+ /*
+ * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
+ * hence in the vmalloc space.
+ */
+ struct page *page = vmalloc_to_page(cpu_addr);
+ return __iommu_dma_get_sgtable_page(sgt, page, size);
+ }
+
+ if (WARN_ON(!area || !area->pages))
+ return -ENXIO;
+
+ return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size,
+ GFP_KERNEL);
+}
+
+static const struct dma_map_ops iommu_dma_ops = {
+ .alloc = iommu_dma_alloc,
+ .free = iommu_dma_free,
+ .mmap = iommu_dma_mmap,
+ .get_sgtable = iommu_dma_get_sgtable,
+ .map_page = iommu_dma_map_page,
+ .unmap_page = iommu_dma_unmap_page,
+ .map_sg = iommu_dma_map_sg,
+ .unmap_sg = iommu_dma_unmap_sg,
+ .sync_single_for_cpu = iommu_dma_sync_single_for_cpu,
+ .sync_single_for_device = iommu_dma_sync_single_for_device,
+ .sync_sg_for_cpu = iommu_dma_sync_sg_for_cpu,
+ .sync_sg_for_device = iommu_dma_sync_sg_for_device,
+ .map_resource = iommu_dma_map_resource,
+ .unmap_resource = iommu_dma_unmap_resource,
+};
+
+/*
+ * The IOMMU core code allocates the default DMA domain, which the underlying
+ * IOMMU driver needs to support via the dma-iommu layer.
+ */
+void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+ const struct iommu_ops *ops)
+{
+ struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
+
+ if (!domain || domain->type != IOMMU_DOMAIN_DMA)
+ goto out_err;
+ if (iommu_dma_init_domain(domain, dma_base, size, dev))
+ goto out_err;
+
+ dev->dma_ops = &iommu_dma_ops;
+ return;
+out_err:
+ pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
+ dev_name(dev));
+}
+
static struct iommu_dma_msi_page *iommu_dma_get_msi_page(struct device *dev,
phys_addr_t msi_addr, struct iommu_domain *domain)
{
@@ -921,3 +1246,5 @@ void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg)
msg->address_lo += lower_32_bits(msi_page->iova);
}
}
+
+arch_initcall(iova_cache_get);
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 10ef708a605c..1d1a3b58d574 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -25,49 +25,14 @@
#include <linux/msi.h>
#include <linux/types.h>

-int iommu_dma_init(void);
-
/* Domain management interface for IOMMU drivers */
int iommu_get_dma_cookie(struct iommu_domain *domain);
int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base);
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, struct device *dev);
-
-/* General helpers for DMA-API <-> IOMMU-API interaction */
-int dma_info_to_prot(enum dma_data_direction dir, bool coherent,
- unsigned long attrs);
-
-/*
- * 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,
- unsigned long attrs, int prot, dma_addr_t *handle);
-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, unsigned long attrs);
-void iommu_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
- enum dma_data_direction dir, unsigned long attrs);
-dma_addr_t iommu_dma_map_resource(struct device *dev, phys_addr_t phys,
- size_t size, enum dma_data_direction dir, unsigned long attrs);
-void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
- size_t size, enum dma_data_direction dir, unsigned long attrs);
+void iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+ const struct iommu_ops *ops);

/* The DMA API isn't _quite_ the whole story, though... */
void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg);
@@ -76,12 +41,13 @@ void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
#else /* CONFIG_IOMMU_DMA */

struct iommu_domain;
+struct iommu_ops;
struct msi_msg;
struct device;

-static inline int iommu_dma_init(void)
+static inline void iommu_setup_dma_ops(struct device *dev, u64 dma_base,
+ u64 size, const struct iommu_ops *ops)
{
- return 0;
}

static inline int iommu_get_dma_cookie(struct iommu_domain *domain)
--
2.20.1