[PATCHv2 1/2] arm: dma-mapping: Refactor attach/detach, alloc/free func
ritesh.harjani at gmail.com
ritesh.harjani at gmail.com
Wed Jun 4 05:54:48 PDT 2014
From: Ritesh Harjani <ritesh.harjani at gmail.com>
Refactor following function calls to lib/iommu-helper.c
1.
arm_iommu_attach/detach device function calls.
arm_iommu_init/release_mapping function calls.
2. iommu_alloc/free_buffer can be moved out from
arm/dma-mapping.c to lib/iommu_helper.c
Signed-off-by: Ritesh Harjani <ritesh.harjani at gmail.com>
---
arch/arm/mm/dma-mapping.c | 200 ++++--------------------------------
include/linux/iommu-helper.h | 18 ++++
lib/iommu-helper.c | 235 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 272 insertions(+), 181 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index b82561e..66cf96b 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1161,98 +1161,6 @@ static inline void __free_iova(struct dma_iommu_mapping *mapping,
spin_unlock_irqrestore(&mapping->lock, flags);
}
-static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
- gfp_t gfp, struct dma_attrs *attrs)
-{
- struct page **pages;
- int count = size >> PAGE_SHIFT;
- int array_size = count * sizeof(struct page *);
- int i = 0;
-
- if (array_size <= PAGE_SIZE)
- pages = kzalloc(array_size, gfp);
- else
- pages = vzalloc(array_size);
- if (!pages)
- return NULL;
-
- if (dma_get_attr(DMA_ATTR_FORCE_CONTIGUOUS, attrs))
- {
- unsigned long order = get_order(size);
- struct page *page;
-
- page = dma_alloc_from_contiguous(dev, count, order);
- if (!page)
- goto error;
-
- __dma_clear_buffer(page, size);
-
- for (i = 0; i < count; i++)
- pages[i] = page + i;
-
- return pages;
- }
-
- /*
- * IOMMU can map any pages, so himem can also be used here
- */
- gfp |= __GFP_NOWARN | __GFP_HIGHMEM;
-
- while (count) {
- int j, order = __fls(count);
-
- pages[i] = alloc_pages(gfp, order);
- while (!pages[i] && order)
- pages[i] = alloc_pages(gfp, --order);
- if (!pages[i])
- goto error;
-
- if (order) {
- split_page(pages[i], order);
- j = 1 << order;
- while (--j)
- pages[i + j] = pages[i] + j;
- }
-
- __dma_clear_buffer(pages[i], PAGE_SIZE << order);
- i += 1 << order;
- count -= 1 << order;
- }
-
- return pages;
-error:
- while (i--)
- if (pages[i])
- __free_pages(pages[i], 0);
- if (array_size <= PAGE_SIZE)
- kfree(pages);
- else
- vfree(pages);
- return NULL;
-}
-
-static int __iommu_free_buffer(struct device *dev, struct page **pages,
- size_t size, struct dma_attrs *attrs)
-{
- int count = size >> PAGE_SHIFT;
- int array_size = count * sizeof(struct page *);
- int i;
-
- if (dma_get_attr(DMA_ATTR_FORCE_CONTIGUOUS, attrs)) {
- dma_release_from_contiguous(dev, pages[0], count);
- } else {
- for (i = 0; i < count; i++)
- if (pages[i])
- __free_pages(pages[i], 0);
- }
-
- if (array_size <= PAGE_SIZE)
- kfree(pages);
- else
- vfree(pages);
- return 0;
-}
-
/*
* Create a CPU mapping for a specified pages
*/
@@ -1417,7 +1325,8 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
*/
gfp &= ~(__GFP_COMP);
- pages = __iommu_alloc_buffer(dev, size, gfp, attrs);
+ pages = iommu_helper_alloc_buffer(dev, size, gfp, attrs,
+ __dma_clear_buffer);
if (!pages)
return NULL;
@@ -1438,7 +1347,7 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
err_mapping:
__iommu_remove_mapping(dev, *handle, size);
err_buffer:
- __iommu_free_buffer(dev, pages, size, attrs);
+ iommu_helper_free_buffer(dev, pages, size, attrs);
return NULL;
}
@@ -1495,7 +1404,7 @@ void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
}
__iommu_remove_mapping(dev, handle, size);
- __iommu_free_buffer(dev, pages, size, attrs);
+ iommu_helper_free_buffer(dev, pages, size, attrs);
}
static int arm_iommu_get_sgtable(struct device *dev, struct sg_table *sgt,
@@ -1924,7 +1833,8 @@ struct dma_map_ops iommu_coherent_ops = {
* @base: start address of the valid IO address space
* @size: maximum size of the valid IO address space
*
- * Creates a mapping structure which holds information about used/unused
+ * Calls for lib/iommu-helper function which creates a mapping
+ * structure which holds information about used/unused
* IO address ranges, which is required to perform memory allocation and
* mapping with IOMMU aware functions.
*
@@ -1934,71 +1844,10 @@ struct dma_map_ops iommu_coherent_ops = {
struct dma_iommu_mapping *
arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size)
{
- unsigned int bits = size >> PAGE_SHIFT;
- unsigned int bitmap_size = BITS_TO_LONGS(bits) * sizeof(long);
- struct dma_iommu_mapping *mapping;
- int extensions = 1;
- int err = -ENOMEM;
-
- if (!bitmap_size)
- return ERR_PTR(-EINVAL);
-
- if (bitmap_size > PAGE_SIZE) {
- extensions = bitmap_size / PAGE_SIZE;
- bitmap_size = PAGE_SIZE;
- }
-
- mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL);
- if (!mapping)
- goto err;
-
- mapping->bitmap_size = bitmap_size;
- mapping->bitmaps = kzalloc(extensions * sizeof(unsigned long *),
- GFP_KERNEL);
- if (!mapping->bitmaps)
- goto err2;
-
- mapping->bitmaps[0] = kzalloc(bitmap_size, GFP_KERNEL);
- if (!mapping->bitmaps[0])
- goto err3;
-
- mapping->nr_bitmaps = 1;
- mapping->extensions = extensions;
- mapping->base = base;
- mapping->bits = BITS_PER_BYTE * bitmap_size;
-
- spin_lock_init(&mapping->lock);
-
- mapping->domain = iommu_domain_alloc(bus);
- if (!mapping->domain)
- goto err4;
-
- kref_init(&mapping->kref);
- return mapping;
-err4:
- kfree(mapping->bitmaps[0]);
-err3:
- kfree(mapping->bitmaps);
-err2:
- kfree(mapping);
-err:
- return ERR_PTR(err);
+ return iommu_helper_init_mapping(bus, base, size);
}
EXPORT_SYMBOL_GPL(arm_iommu_create_mapping);
-static void release_iommu_mapping(struct kref *kref)
-{
- int i;
- struct dma_iommu_mapping *mapping =
- container_of(kref, struct dma_iommu_mapping, kref);
-
- iommu_domain_free(mapping->domain);
- for (i = 0; i < mapping->nr_bitmaps; i++)
- kfree(mapping->bitmaps[i]);
- kfree(mapping->bitmaps);
- kfree(mapping);
-}
-
static int extend_iommu_mapping(struct dma_iommu_mapping *mapping)
{
int next_bitmap;
@@ -2019,8 +1868,7 @@ static int extend_iommu_mapping(struct dma_iommu_mapping *mapping)
void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping)
{
- if (mapping)
- kref_put(&mapping->kref, release_iommu_mapping);
+ iommu_helper_release_mapping(mapping);
}
EXPORT_SYMBOL_GPL(arm_iommu_release_mapping);
@@ -2030,8 +1878,9 @@ EXPORT_SYMBOL_GPL(arm_iommu_release_mapping);
* @mapping: io address space mapping structure (returned from
* arm_iommu_create_mapping)
*
- * Attaches specified io address space mapping to the provided device,
- * this replaces the dma operations (dma_map_ops pointer) with the
+ * Calls for lib/iommu-helper which attaches specified io
+ * address space mapping to the provided device, this
+ * replaces the dma operations (dma_map_ops pointer) with the
* IOMMU aware version. More than one client might be attached to
* the same io address space mapping.
*/
@@ -2040,13 +1889,12 @@ int arm_iommu_attach_device(struct device *dev,
{
int err;
- err = iommu_attach_device(mapping->domain, dev);
- if (err)
- return err;
+ err = iommu_helper_attach_device(dev, mapping);
- kref_get(&mapping->kref);
- dev->mapping = mapping;
- set_dma_ops(dev, &iommu_ops);
+ if (!err)
+ set_dma_ops(dev, &iommu_ops);
+ else
+ return err;
pr_debug("Attached IOMMU controller to %s device.\n", dev_name(dev));
return 0;
@@ -2057,24 +1905,14 @@ EXPORT_SYMBOL_GPL(arm_iommu_attach_device);
* arm_iommu_detach_device
* @dev: valid struct device pointer
*
- * Detaches the provided device from a previously attached map.
+ * Calls for lib/iommu-helper which detaches the provided
+ * device from a previously attached map.
* This voids the dma operations (dma_map_ops pointer)
*/
void arm_iommu_detach_device(struct device *dev)
{
- struct dma_iommu_mapping *mapping;
-
- mapping = to_dma_iommu_mapping(dev);
- if (!mapping) {
- dev_warn(dev, "Not attached\n");
- return;
- }
-
- iommu_detach_device(mapping->domain, dev);
- kref_put(&mapping->kref, release_iommu_mapping);
- dev->mapping = NULL;
+ iommu_helper_detach_device(dev);
set_dma_ops(dev, NULL);
-
pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev));
}
EXPORT_SYMBOL_GPL(arm_iommu_detach_device);
diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h
index 0c5e4c7..9c4c2ae 100644
--- a/include/linux/iommu-helper.h
+++ b/include/linux/iommu-helper.h
@@ -2,6 +2,7 @@
#define _LINUX_IOMMU_HELPER_H
#include <linux/kernel.h>
+#include <linux/dma-attrs.h>
#ifdef CONFIG_DMA_USE_IOMMU_HELPER_MAPPING
struct dma_iommu_mapping {
@@ -19,6 +20,23 @@ struct dma_iommu_mapping {
struct kref kref;
};
+extern struct page **iommu_helper_alloc_buffer(struct device *dev, size_t size,
+ gfp_t gfp, struct dma_attrs *attrs,
+ void (*arch_clear_buffer_cb)(struct page*, size_t));
+
+extern int iommu_helper_free_buffer(struct device *dev, struct page **pages,
+ size_t size, struct dma_attrs *attrs);
+
+extern void iommu_helper_detach_device(struct device *dev);
+
+extern void iommu_helper_release_mapping(struct dma_iommu_mapping *mapping);
+
+extern int iommu_helper_attach_device(struct device *dev,
+ struct dma_iommu_mapping *mapping);
+
+extern struct dma_iommu_mapping *
+iommu_helper_init_mapping(struct bus_type *bus, dma_addr_t base, size_t size);
+
#define to_dma_iommu_mapping(dev) ((dev)->mapping)
#else
#define to_dma_iommu_mapping(dev) NULL
diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c
index c27e269..3664709 100644
--- a/lib/iommu-helper.c
+++ b/lib/iommu-helper.c
@@ -6,6 +6,17 @@
#include <linux/bitmap.h>
#include <linux/bug.h>
+#ifdef CONFIG_DMA_USE_IOMMU_HELPER_MAPPING
+#include <linux/iommu.h>
+#include <linux/device.h>
+#include <linux/iommu-helper.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/errno.h>
+#include <linux/dma-contiguous.h>
+#include <linux/mm.h>
+#endif
+
int iommu_is_span_boundary(unsigned int index, unsigned int nr,
unsigned long shift,
unsigned long boundary_size)
@@ -39,3 +50,227 @@ again:
return -1;
}
EXPORT_SYMBOL(iommu_area_alloc);
+
+#ifdef CONFIG_DMA_USE_IOMMU_HELPER_MAPPING
+
+struct page **iommu_helper_alloc_buffer(struct device *dev, size_t size,
+ gfp_t gfp, struct dma_attrs *attrs,
+ void (*arch_clear_buffer_cb)(struct page*, size_t))
+{
+ struct page **pages;
+ int count = size >> PAGE_SHIFT;
+ int array_size = count * sizeof(struct page *);
+ int i = 0;
+
+ if (array_size <= PAGE_SIZE)
+ pages = kzalloc(array_size, gfp);
+ else
+ pages = vzalloc(array_size);
+ if (!pages)
+ return NULL;
+
+ if (dma_get_attr(DMA_ATTR_FORCE_CONTIGUOUS, attrs)) {
+ unsigned long order = get_order(size);
+ struct page *page;
+
+ page = dma_alloc_from_contiguous(dev, count, order);
+ if (!page)
+ goto error;
+
+ if (arch_clear_buffer_cb)
+ arch_clear_buffer_cb(page, size);
+
+ for (i = 0; i < count; i++)
+ pages[i] = page + i;
+
+ return pages;
+ }
+
+ /*
+ * IOMMU can map any pages, so himem can also be used here
+ */
+ gfp |= __GFP_NOWARN | __GFP_HIGHMEM;
+
+ while (count) {
+ int j, order = __fls(count);
+
+ pages[i] = alloc_pages(gfp, order);
+ while (!pages[i] && order)
+ pages[i] = alloc_pages(gfp, --order);
+ if (!pages[i])
+ goto error;
+
+ if (order) {
+ split_page(pages[i], order);
+ j = 1 << order;
+ while (--j)
+ pages[i + j] = pages[i] + j;
+ }
+ if (arch_clear_buffer_cb)
+ arch_clear_buffer_cb(pages[i], PAGE_SIZE << order);
+ i += 1 << order;
+ count -= 1 << order;
+ }
+
+ return pages;
+error:
+ while (i--)
+ if (pages[i])
+ __free_pages(pages[i], 0);
+ if (array_size <= PAGE_SIZE)
+ kfree(pages);
+ else
+ vfree(pages);
+ return NULL;
+}
+
+int iommu_helper_free_buffer(struct device *dev, struct page **pages,
+ size_t size, struct dma_attrs *attrs)
+{
+ int count = size >> PAGE_SHIFT;
+ int array_size = count * sizeof(struct page *);
+ int i;
+
+ if (dma_get_attr(DMA_ATTR_FORCE_CONTIGUOUS, attrs)) {
+ dma_release_from_contiguous(dev, pages[0], count);
+ } else {
+ for (i = 0; i < count; i++)
+ if (pages[i])
+ __free_pages(pages[i], 0);
+ }
+
+ if (array_size <= PAGE_SIZE)
+ kfree(pages);
+ else
+ vfree(pages);
+ return 0;
+}
+
+/**
+ * iommu_helper_init_mapping
+ * @bus: pointer to the bus holding the client device (for IOMMU calls)
+ * @base: start address of the valid IO address space
+ * @size: maximum size of the valid IO address space
+ *
+ * Creates a mapping structure which holds information about used/unused
+ * IO address ranges, which is required to perform memory allocation and
+ * mapping with IOMMU aware functions.
+ *
+ */
+
+struct dma_iommu_mapping *
+iommu_helper_init_mapping(struct bus_type *bus, dma_addr_t base, size_t size)
+{
+ unsigned int bits = size >> PAGE_SHIFT;
+ unsigned int bitmap_size = BITS_TO_LONGS(bits) * sizeof(long);
+ struct dma_iommu_mapping *mapping;
+ int extensions = 1;
+ int err = -ENOMEM;
+
+ if (!bitmap_size)
+ return ERR_PTR(-EINVAL);
+
+ if (bitmap_size > PAGE_SIZE) {
+ extensions = bitmap_size / PAGE_SIZE;
+ bitmap_size = PAGE_SIZE;
+ }
+
+ mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL);
+ if (!mapping)
+ goto err;
+
+ mapping->bitmap_size = bitmap_size;
+ mapping->bitmaps = kzalloc(extensions * sizeof(unsigned long *),
+ GFP_KERNEL);
+ if (!mapping->bitmaps)
+ goto err2;
+
+ mapping->bitmaps[0] = kzalloc(bitmap_size, GFP_KERNEL);
+ if (!mapping->bitmaps[0])
+ goto err3;
+
+ mapping->nr_bitmaps = 1;
+ mapping->extensions = extensions;
+ mapping->base = base;
+ mapping->bits = BITS_PER_BYTE * bitmap_size;
+
+ spin_lock_init(&mapping->lock);
+
+ mapping->domain = iommu_domain_alloc(bus);
+ if (!mapping->domain)
+ goto err4;
+
+ kref_init(&mapping->kref);
+ return mapping;
+err4:
+ kfree(mapping->bitmaps[0]);
+err3:
+ kfree(mapping->bitmaps);
+err2:
+ kfree(mapping);
+err:
+ return ERR_PTR(err);
+}
+
+static void release_iommu_mapping(struct kref *kref)
+{
+ int i;
+ struct dma_iommu_mapping *mapping =
+ container_of(kref, struct dma_iommu_mapping, kref);
+
+ iommu_domain_free(mapping->domain);
+ for (i = 0; i < mapping->nr_bitmaps; i++)
+ kfree(mapping->bitmaps[i]);
+ kfree(mapping->bitmaps);
+ kfree(mapping);
+}
+
+
+void iommu_helper_release_mapping(struct dma_iommu_mapping *mapping)
+{
+ if (mapping)
+ kref_put(&mapping->kref, release_iommu_mapping);
+}
+
+/**
+ * iommu_helper_detach_device
+ * @dev: valid struct device pointer
+ *
+ * Detaches the provided device from a previously attached map.
+ */
+void iommu_helper_detach_device(struct device *dev)
+{
+ struct dma_iommu_mapping *mapping;
+
+ mapping = to_dma_iommu_mapping(dev);
+ if (!mapping) {
+ dev_warn(dev, "Not attached\n");
+ return;
+ }
+
+ iommu_detach_device(mapping->domain, dev);
+ kref_put(&mapping->kref, release_iommu_mapping);
+ dev->mapping = NULL;
+}
+
+/**
+ * iommu_helper_attach_device
+ * @dev: valid struct device pointer
+ * @mapping: io address space mapping structure
+ *
+ * Attaches specified io address space mapping to the provided device.
+ */
+int iommu_helper_attach_device(struct device *dev,
+ struct dma_iommu_mapping *mapping)
+{
+ int err;
+
+ err = iommu_attach_device(mapping->domain, dev);
+ if (err)
+ return err;
+
+ kref_get(&mapping->kref);
+ dev->mapping = mapping;
+ return 0;
+}
+#endif
--
1.8.1.3
More information about the linux-arm-kernel
mailing list