[PATCH 107/115] ion: use alloc_pages in system contig heap

John Stultz
2013-12-14T03:27:53Z

From: Colin Cross <ccross@android.com>

There is no reason to use kzalloc, just call alloc_pages directly.
Change the GFP from GFP_KERNEL to include __GFP_HIGH, to allow it
to return contiguous pages from highmem. virt_to_* functions
aren't valid on highmem pages, so store the struct page * in an
sg_table in buffer->priv_virt like most other heaps, and replace
virt_to_* with page_to_*.

Signed-off-by: Colin Cross <ccross@android.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---
drivers/staging/android/ion/ion_system_heap.c | 71 ++++++++++++++++++---------
1 file changed, 48 insertions(+), 23 deletions(-)

diff --git a/drivers/staging/android/ion/ion_system_heap.c b/drivers/staging/android/ion/ion_system_heap.c
index 53afa33..841511d 100644
--- a/drivers/staging/android/ion/ion_system_heap.c
+++ b/drivers/staging/android/ion/ion_system_heap.c
@@ -360,29 +360,69 @@ static int ion_system_contig_heap_allocate(struct ion_heap *heap,
unsigned long flags)
{
int order = get_order(len);
+ struct page *page;
+ struct sg_table *table;
+ unsigned long i;
+ int ret;

if (align > (PAGE_SIZE << order))
return -EINVAL;

- if (ion_buffer_fault_user_mappings(buffer))
- return -EINVAL;
-
- buffer->priv_virt = kzalloc(len, GFP_KERNEL);
- if (!buffer->priv_virt)
+ page = alloc_pages(low_order_gfp_flags, order);
+ if (!page)
return -ENOMEM;
+
+ split_page(page, order);
+
+ len = PAGE_ALIGN(len);
+ for (i = len >> PAGE_SHIFT; i < (1 << order); i++)
+ __free_page(page + i);
+
+ table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
+ if (!table) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = sg_alloc_table(table, 1, GFP_KERNEL);
+ if (ret)
+ goto out;
+
+ sg_set_page(table->sgl, page, len, 0);
+
+ buffer->priv_virt = table;
+
+ ion_pages_sync_for_device(NULL, page, len, DMA_BIDIRECTIONAL);
+
return 0;
+
+out:
+ for (i = 0; i < len >> PAGE_SHIFT; i++)
+ __free_page(page + i);
+ kfree(table);
+ return ret;
}

void ion_system_contig_heap_free(struct ion_buffer *buffer)
{
- kfree(buffer->priv_virt);
+ struct sg_table *table = buffer->priv_virt;
+ struct page *page = sg_page(table->sgl);
+ unsigned long pages = PAGE_ALIGN(buffer->size) >> PAGE_SHIFT;
+ unsigned long i;
+
+ for (i = 0; i < pages; i++)
+ __free_page(page + i);
+ sg_free_table(table);
+ kfree(table);
}

static int ion_system_contig_heap_phys(struct ion_heap *heap,
struct ion_buffer *buffer,
ion_phys_addr_t *addr, size_t *len)
{
- *addr = virt_to_phys(buffer->priv_virt);
+ struct sg_table *table = buffer->priv_virt;
+ struct page *page = sg_page(table->sgl);
+ *addr = page_to_phys(page);
*len = buffer->size;
return 0;
}
@@ -390,27 +430,12 @@ static int ion_system_contig_heap_phys(struct ion_heap *heap,
struct sg_table *ion_system_contig_heap_map_dma(struct ion_heap *heap,
struct ion_buffer *buffer)
{
- struct sg_table *table;
- int ret;
-
- table = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
- if (!table)
- return ERR_PTR(-ENOMEM);
- ret = sg_alloc_table(table, 1, GFP_KERNEL);
- if (ret) {
- kfree(table);
- return ERR_PTR(ret);
- }
- sg_set_page(table->sgl, virt_to_page(buffer->priv_virt), buffer->size,
- 0);
- return table;
+ return buffer->priv_virt;
}

void ion_system_contig_heap_unmap_dma(struct ion_heap *heap,
struct ion_buffer *buffer)
{
- sg_free_table(buffer->sg_table);
- kfree(buffer->sg_table);
}

static struct ion_heap_ops kmalloc_ops = {
--
1.8.3.2