On 02/12/2018 08:42 PM, Laura Abbott wrote:
> On 02/10/2018 02:17 AM, Alexey Skidanov wrote:
>> Current ion defined allocation ioctl doesn't allow to specify the
>> requested
>> allocation alignment. CMA heap allocates buffers aligned on buffer size
>> page order.
>>
>> Sometimes, the alignment requirement is less restrictive. In such cases,
>> providing specific alignment may reduce the external memory fragmentation
>> and in some cases it may avoid the allocation request failure.
>>
>
> I really do not want to bring this back as part of the regular
> ABI.
Yes, I know it was removed in 4.12.
Having an alignment parameter that gets used for exactly
> one heap only leads to confusion (which is why it was removed
> from the ABI in the first place).
You are correct regarding the CMA heap. But, probably it may be used by
custom heap as well.
>
> The alignment came from the behavior of the DMA APIs. Do you
> actually need to specify any alignment from userspace or do
> you only need page size?
Yes. If CMA gives it for free, I would suggest to let the ion user to decide
>
> Thanks,
> Laura
>
Thanks,
Alexey
>> To fix this, we add an alignment parameter to the allocation ioctl.
>>
>> Signed-off-by: Alexey Skidanov <alexey.skidanov@xxxxxxxxx>
>> ---
>> drivers/staging/android/ion/ion-ioctl.c | 3 ++-
>> drivers/staging/android/ion/ion.c | 14 +++++++++-----
>> drivers/staging/android/ion/ion.h | 9 ++++++---
>> drivers/staging/android/ion/ion_carveout_heap.c | 3 ++-
>> drivers/staging/android/ion/ion_chunk_heap.c | 3 ++-
>> drivers/staging/android/ion/ion_cma_heap.c | 18 ++++++++++++------
>> drivers/staging/android/ion/ion_system_heap.c | 6 ++++--
>> drivers/staging/android/uapi/ion.h | 7 +++----
>> 8 files changed, 40 insertions(+), 23 deletions(-)
>>
>> diff --git a/drivers/staging/android/ion/ion-ioctl.c
>> b/drivers/staging/android/ion/ion-ioctl.c
>> index c789893..9fe022b 100644
>> --- a/drivers/staging/android/ion/ion-ioctl.c
>> +++ b/drivers/staging/android/ion/ion-ioctl.c
>> @@ -83,7 +83,8 @@ long ion_ioctl(struct file *filp, unsigned int cmd,
>> unsigned long arg)
>> fd = ion_alloc(data.allocation.len,
>> data.allocation.heap_id_mask,
>> - data.allocation.flags);
>> + data.allocation.flags,
>> + data.allocation.align);
>> if (fd < 0)
>> return fd;
>> diff --git a/drivers/staging/android/ion/ion.c
>> b/drivers/staging/android/ion/ion.c
>> index f480885..35ddc7a 100644
>> --- a/drivers/staging/android/ion/ion.c
>> +++ b/drivers/staging/android/ion/ion.c
>> @@ -78,7 +78,8 @@ static void ion_buffer_add(struct ion_device *dev,
>> static struct ion_buffer *ion_buffer_create(struct ion_heap *heap,
>> struct ion_device *dev,
>> unsigned long len,
>> - unsigned long flags)
>> + unsigned long flags,
>> + unsigned int align)
>> {
>> struct ion_buffer *buffer;
>> int ret;
>> @@ -90,14 +91,14 @@ static struct ion_buffer *ion_buffer_create(struct
>> ion_heap *heap,
>> buffer->heap = heap;
>> buffer->flags = flags;
>> - ret = heap->ops->allocate(heap, buffer, len, flags);
>> + ret = heap->ops->allocate(heap, buffer, len, flags, align);
>> if (ret) {
>> if (!(heap->flags & ION_HEAP_FLAG_DEFER_FREE))
>> goto err2;
>> ion_heap_freelist_drain(heap, 0);
>> - ret = heap->ops->allocate(heap, buffer, len, flags);
>> + ret = heap->ops->allocate(heap, buffer, len, flags, align);
>> if (ret)
>> goto err2;
>> }
>> @@ -390,7 +391,10 @@ static const struct dma_buf_ops dma_buf_ops = {
>> .unmap = ion_dma_buf_kunmap,
>> };
>> -int ion_alloc(size_t len, unsigned int heap_id_mask, unsigned int
>> flags)
>> +int ion_alloc(size_t len,
>> + unsigned int heap_id_mask,
>> + unsigned int flags,
>> + unsigned int align)
>> {
>> struct ion_device *dev = internal_dev;
>> struct ion_buffer *buffer = NULL;
>> @@ -417,7 +421,7 @@ int ion_alloc(size_t len, unsigned int
>> heap_id_mask, unsigned int flags)
>> /* if the caller didn't specify this heap id */
>> if (!((1 << heap->id) & heap_id_mask))
>> continue;
>> - buffer = ion_buffer_create(heap, dev, len, flags);
>> + buffer = ion_buffer_create(heap, dev, len, flags, align);
>> if (!IS_ERR(buffer))
>> break;
>> }
>> diff --git a/drivers/staging/android/ion/ion.h
>> b/drivers/staging/android/ion/ion.h
>> index f5f9cd6..0c161d2 100644
>> --- a/drivers/staging/android/ion/ion.h
>> +++ b/drivers/staging/android/ion/ion.h
>> @@ -123,8 +123,10 @@ struct ion_device {
>> */
>> struct ion_heap_ops {
>> int (*allocate)(struct ion_heap *heap,
>> - struct ion_buffer *buffer, unsigned long len,
>> - unsigned long flags);
>> + struct ion_buffer *buffer,
>> + unsigned long len,
>> + unsigned long flags,
>> + unsigned int align);
>> void (*free)(struct ion_buffer *buffer);
>> void * (*map_kernel)(struct ion_heap *heap, struct ion_buffer
>> *buffer);
>> void (*unmap_kernel)(struct ion_heap *heap, struct ion_buffer
>> *buffer);
>> @@ -228,7 +230,8 @@ int ion_heap_pages_zero(struct page *page, size_t
>> size, pgprot_t pgprot);
>> int ion_alloc(size_t len,
>> unsigned int heap_id_mask,
>> - unsigned int flags);
>> + unsigned int flags,
>> + unsigned int align);
>> /**
>> * ion_heap_init_shrinker
>> diff --git a/drivers/staging/android/ion/ion_carveout_heap.c
>> b/drivers/staging/android/ion/ion_carveout_heap.c
>> index fee7650..deae9dd 100644
>> --- a/drivers/staging/android/ion/ion_carveout_heap.c
>> +++ b/drivers/staging/android/ion/ion_carveout_heap.c
>> @@ -59,7 +59,8 @@ static void ion_carveout_free(struct ion_heap *heap,
>> phys_addr_t addr,
>> static int ion_carveout_heap_allocate(struct ion_heap *heap,
>> struct ion_buffer *buffer,
>> unsigned long size,
>> - unsigned long flags)
>> + unsigned long flags,
>> + unsigned int align)
>> {
>> struct sg_table *table;
>> phys_addr_t paddr;
>> diff --git a/drivers/staging/android/ion/ion_chunk_heap.c
>> b/drivers/staging/android/ion/ion_chunk_heap.c
>> index 102c093..15f9518 100644
>> --- a/drivers/staging/android/ion/ion_chunk_heap.c
>> +++ b/drivers/staging/android/ion/ion_chunk_heap.c
>> @@ -35,7 +35,8 @@ struct ion_chunk_heap {
>> static int ion_chunk_heap_allocate(struct ion_heap *heap,
>> struct ion_buffer *buffer,
>> unsigned long size,
>> - unsigned long flags)
>> + unsigned long flags,
>> + unsigned int align)
>> {
>> struct ion_chunk_heap *chunk_heap =
>> container_of(heap, struct ion_chunk_heap, heap);
>> diff --git a/drivers/staging/android/ion/ion_cma_heap.c
>> b/drivers/staging/android/ion/ion_cma_heap.c
>> index 86196ff..f3f8deb 100644
>> --- a/drivers/staging/android/ion/ion_cma_heap.c
>> +++ b/drivers/staging/android/ion/ion_cma_heap.c
>> @@ -32,25 +32,31 @@ struct ion_cma_heap {
>> #define to_cma_heap(x) container_of(x, struct ion_cma_heap, heap)
>> /* ION CMA heap operations functions */
>> -static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer
>> *buffer,
>> +static int ion_cma_allocate(struct ion_heap *heap,
>> + struct ion_buffer *buffer,
>> unsigned long len,
>> - unsigned long flags)
>> + unsigned long flags,
>> + unsigned int align)
>> {
>> struct ion_cma_heap *cma_heap = to_cma_heap(heap);
>> struct sg_table *table;
>> struct page *pages;
>> unsigned long size = PAGE_ALIGN(len);
>> unsigned long nr_pages = size >> PAGE_SHIFT;
>> - unsigned long align = get_order(size);
>> + int order = get_order(align);
>> int ret;
>> - if (align > CONFIG_CMA_ALIGNMENT)
>> - align = CONFIG_CMA_ALIGNMENT;
>> + /* CMA allocation alignment is in PAGE_SIZE order */
>> + if (order > CONFIG_CMA_ALIGNMENT)
>> + order = CONFIG_CMA_ALIGNMENT;
>> - pages = cma_alloc(cma_heap->cma, nr_pages, align, GFP_KERNEL);
>> + pages = cma_alloc(cma_heap->cma, nr_pages, order, GFP_KERNEL);
>> if (!pages)
>> return -ENOMEM;
>> + pr_debug("Allocated block of %lu pages starting at 0x%lX",
>> + nr_pages, page_to_pfn(pages));
>> +
>> table = kmalloc(sizeof(*table), GFP_KERNEL);
>> if (!table)
>> goto err;
>> diff --git a/drivers/staging/android/ion/ion_system_heap.c
>> b/drivers/staging/android/ion/ion_system_heap.c
>> index 4dc5d7a..b5a1720 100644
>> --- a/drivers/staging/android/ion/ion_system_heap.c
>> +++ b/drivers/staging/android/ion/ion_system_heap.c
>> @@ -125,7 +125,8 @@ static struct page *alloc_largest_available(struct
>> ion_system_heap *heap,
>> static int ion_system_heap_allocate(struct ion_heap *heap,
>> struct ion_buffer *buffer,
>> unsigned long size,
>> - unsigned long flags)
>> + unsigned long flags,
>> + unsigned int align)
>> {
>> struct ion_system_heap *sys_heap = container_of(heap,
>> struct ion_system_heap,
>> @@ -363,7 +364,8 @@ device_initcall(ion_system_heap_create);
>> static int ion_system_contig_heap_allocate(struct ion_heap *heap,
>> struct ion_buffer *buffer,
>> unsigned long len,
>> - unsigned long flags)
>> + unsigned long flags,
>> + unsigned int align)
>> {
>> int order = get_order(len);
>> struct page *page;
>> diff --git a/drivers/staging/android/uapi/ion.h
>> b/drivers/staging/android/uapi/ion.h
>> index 9e21451..b093edd 100644
>> --- a/drivers/staging/android/uapi/ion.h
>> +++ b/drivers/staging/android/uapi/ion.h
>> @@ -70,9 +70,8 @@ enum ion_heap_type {
>> * @len: size of the allocation
>> * @heap_id_mask: mask of heap ids to allocate from
>> * @flags: flags passed to heap
>> - * @handle: pointer that will be populated with a cookie to
>> use to
>> - * refer to this allocation
>> - *
>> + * @fd: file descriptor associated with newly allocated buffer
>> + * @align: allocation alignment
>> * Provided by userspace as an argument to the ioctl
>> */
>> struct ion_allocation_data {
>> @@ -80,7 +79,7 @@ struct ion_allocation_data {
>> __u32 heap_id_mask;
>> __u32 flags;
>> __u32 fd;
>> - __u32 unused;
>> + __u32 align;
>> };
>> #define MAX_HEAP_NAME 32
>>
>
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