staging: android: ion: Use CMA APIs directly

When CMA was first introduced, its primary use was for DMA allocation
and the only way to get CMA memory was to call dma_alloc_coherent. This
put Ion in an awkward position since there was no device structure
readily available and setting one up messed up the coherency model.
These days, CMA can be allocated directly from the APIs. Switch to using
this model to avoid needing a dummy device. This also mitigates some of
the caching problems (e.g. dma_alloc_coherent only returning uncached
memory).

Signed-off-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/android/ion/Kconfig b/drivers/staging/android/ion/Kconfig
index 206c4de8feac093ba4a0379bf8f2dae6d88df4b2..15108c40c81fa89c1fd9a01850f3c1f95f1a7bb3 100644 (file)
--- a/drivers/staging/android/ion/Kconfig
+++ b/drivers/staging/android/ion/Kconfig
@@ -10,3 +10,10 @@ menuconfig ION
          If you're not using Android its probably safe to
          say N here.
 
+config ION_CMA_HEAP
+       bool "Ion CMA heap support"
+       depends on ION && CMA
+       help
+         Choose this option to enable CMA heaps with Ion. This heap is backed
+         by the Contiguous Memory Allocator (CMA). If your system has these
+         regions, you should say Y here.

diff --git a/drivers/staging/android/ion/Makefile b/drivers/staging/android/ion/Makefile
index 26672a061b3440011a16b6f6b25a3a8399f1ec2f..66d0c4a31ed74417619dbedf913082bf0b397c6b 100644 (file)
--- a/drivers/staging/android/ion/Makefile
+++ b/drivers/staging/android/ion/Makefile
@@ -1,6 +1,7 @@
 obj-$(CONFIG_ION) +=   ion.o ion-ioctl.o ion_heap.o \
                        ion_page_pool.o ion_system_heap.o \
-                       ion_carveout_heap.o ion_chunk_heap.o ion_cma_heap.o
+                       ion_carveout_heap.o ion_chunk_heap.o
+obj-$(CONFIG_ION_CMA_HEAP) += ion_cma_heap.o
 ifdef CONFIG_COMPAT
 obj-$(CONFIG_ION) += compat_ion.o
 endif

diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c
index d562fd75c1310b231b9f0295687167d1c9746b67..f3e0f599b25bc7dea8aa5e6dd1690abf184cb8bd 100644 (file)
--- a/drivers/staging/android/ion/ion_cma_heap.c
+++ b/drivers/staging/android/ion/ion_cma_heap.c
@@ -19,24 +19,19 @@
 #include <linux/slab.h>
 #include <linux/errno.h>
 #include <linux/err.h>
-#include <linux/dma-mapping.h>
+#include <linux/cma.h>
+#include <linux/scatterlist.h>
 
 #include "ion.h"
 #include "ion_priv.h"
 
 struct ion_cma_heap {
        struct ion_heap heap;
-       struct device *dev;
+       struct cma *cma;
 };
 
 #define to_cma_heap(x) container_of(x, struct ion_cma_heap, heap)
 
-struct ion_cma_buffer_info {
-       void *cpu_addr;
-       dma_addr_t handle;
-       struct sg_table *table;
-};
-
 
 /* ION CMA heap operations functions */
 static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
@@ -44,93 +39,53 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
                            unsigned long flags)
 {
        struct ion_cma_heap *cma_heap = to_cma_heap(heap);
-       struct device *dev = cma_heap->dev;
-       struct ion_cma_buffer_info *info;
-
-       dev_dbg(dev, "Request buffer allocation len %ld\n", len);
-
-       if (buffer->flags & ION_FLAG_CACHED)
-               return -EINVAL;
+       struct sg_table *table;
+       struct page *pages;
+       int ret;
 
-       info = kzalloc(sizeof(*info), GFP_KERNEL);
-       if (!info)
+       pages = cma_alloc(cma_heap->cma, len, 0, GFP_KERNEL);
+       if (!pages)
                return -ENOMEM;
 
-       info->cpu_addr = dma_alloc_coherent(dev, len, &(info->handle),
-                                               GFP_HIGHUSER | __GFP_ZERO);
-
-       if (!info->cpu_addr) {
-               dev_err(dev, "Fail to allocate buffer\n");
+       table = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
+       if (!table)
                goto err;
-       }
 
-       info->table = kmalloc(sizeof(*info->table), GFP_KERNEL);
-       if (!info->table)
+       ret = sg_alloc_table(table, 1, GFP_KERNEL);
+       if (ret)
                goto free_mem;
 
-       if (dma_get_sgtable(dev, info->table, info->cpu_addr, info->handle,
-                           len))
-               goto free_table;
-       /* keep this for memory release */
-       buffer->priv_virt = info;
-       buffer->sg_table = info->table;
-       dev_dbg(dev, "Allocate buffer %p\n", buffer);
+       sg_set_page(table->sgl, pages, len, 0);
+
+       buffer->priv_virt = pages;
+       buffer->sg_table = table;
        return 0;
 
-free_table:
-       kfree(info->table);
 free_mem:
-       dma_free_coherent(dev, len, info->cpu_addr, info->handle);
+       kfree(table);
 err:
-       kfree(info);
+       cma_release(cma_heap->cma, pages, buffer->size);
        return -ENOMEM;
 }
 
 static void ion_cma_free(struct ion_buffer *buffer)
 {
        struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
-       struct device *dev = cma_heap->dev;
-       struct ion_cma_buffer_info *info = buffer->priv_virt;
+       struct page *pages = buffer->priv_virt;
 
-       dev_dbg(dev, "Release buffer %p\n", buffer);
        /* release memory */
-       dma_free_coherent(dev, buffer->size, info->cpu_addr, info->handle);
+       cma_release(cma_heap->cma, pages, buffer->size);
        /* release sg table */
-       sg_free_table(info->table);
-       kfree(info->table);
-       kfree(info);
-}
-
-static int ion_cma_mmap(struct ion_heap *mapper, struct ion_buffer *buffer,
-                       struct vm_area_struct *vma)
-{
-       struct ion_cma_heap *cma_heap = to_cma_heap(buffer->heap);
-       struct device *dev = cma_heap->dev;
-       struct ion_cma_buffer_info *info = buffer->priv_virt;
-
-       return dma_mmap_coherent(dev, vma, info->cpu_addr, info->handle,
-                                buffer->size);
-}
-
-static void *ion_cma_map_kernel(struct ion_heap *heap,
-                               struct ion_buffer *buffer)
-{
-       struct ion_cma_buffer_info *info = buffer->priv_virt;
-       /* kernel memory mapping has been done at allocation time */
-       return info->cpu_addr;
-}
-
-static void ion_cma_unmap_kernel(struct ion_heap *heap,
-                                struct ion_buffer *buffer)
-{
+       sg_free_table(buffer->sg_table);
+       kfree(buffer->sg_table);
 }
 
 static struct ion_heap_ops ion_cma_ops = {
        .allocate = ion_cma_allocate,
        .free = ion_cma_free,
-       .map_user = ion_cma_mmap,
-       .map_kernel = ion_cma_map_kernel,
-       .unmap_kernel = ion_cma_unmap_kernel,
+       .map_user = ion_heap_map_user,
+       .map_kernel = ion_heap_map_kernel,
+       .unmap_kernel = ion_heap_unmap_kernel,
 };
 
 struct ion_heap *ion_cma_heap_create(struct ion_platform_heap *data)
@@ -147,7 +102,7 @@ struct ion_heap *ion_cma_heap_create(struct ion_platform_heap *data)
         * get device from private heaps data, later it will be
         * used to make the link with reserved CMA memory
         */
-       cma_heap->dev = data->priv;
+       cma_heap->cma = data->priv;
        cma_heap->heap.type = ION_HEAP_TYPE_DMA;
        return &cma_heap->heap;
 }

diff --git a/drivers/staging/android/ion/ion_heap.c b/drivers/staging/android/ion/ion_heap.c
index c69d0bd536934a44998317b79bdb814b2572516a..66f8fc5c8ceed641c7419f5bd8ba8ca85d5f6a08 100644 (file)
--- a/drivers/staging/android/ion/ion_heap.c
+++ b/drivers/staging/android/ion/ion_heap.c
@@ -333,9 +333,11 @@ struct ion_heap *ion_heap_create(struct ion_platform_heap *heap_data)
        case ION_HEAP_TYPE_CHUNK:
                heap = ion_chunk_heap_create(heap_data);
                break;
+#ifdef CONFIG_ION_CMA_HEAP
        case ION_HEAP_TYPE_DMA:
                heap = ion_cma_heap_create(heap_data);
                break;
+#endif
        default:
                pr_err("%s: Invalid heap type %d\n", __func__,
                       heap_data->type);
@@ -373,9 +375,11 @@ void ion_heap_destroy(struct ion_heap *heap)
        case ION_HEAP_TYPE_CHUNK:
                ion_chunk_heap_destroy(heap);
                break;
+#ifdef CONFIG_ION_CMA_HEAP
        case ION_HEAP_TYPE_DMA:
                ion_cma_heap_destroy(heap);
                break;
+#endif
        default:
                pr_err("%s: Invalid heap type %d\n", __func__,
                       heap->type);