On 12/19/18 9:19 AM, Zeng Tao wrote:

In some usecases, the buffer cached attribute is not determined at allocation time, it's determined just before the real cpu mapping. And from the memory view of point, a buffer should not have the cached attribute util is really mapped by the cpu. So in this patch, we introduced the new ioctl command to target the requirement.

This is racy and error prone. Can you explain more what problem you are trying to solve?

Signed-off-by: Zeng Tao prime.zeng@hisilicon.com

drivers/staging/android/ion/ion-ioctl.c | 4 ++++ drivers/staging/android/ion/ion.c | 17 +++++++++++++++++ drivers/staging/android/ion/ion.h | 1 + drivers/staging/android/uapi/ion.h | 22 ++++++++++++++++++++++ 4 files changed, 44 insertions(+)

diff --git a/drivers/staging/android/ion/ion-ioctl.c b/drivers/staging/android/ion/ion-ioctl.c index a8d3cc4..60bb702 100644 --- a/drivers/staging/android/ion/ion-ioctl.c +++ b/drivers/staging/android/ion/ion-ioctl.c @@ -12,6 +12,7 @@ union ion_ioctl_arg { struct ion_allocation_data allocation;

• struct ion_buffer_flag_data update; struct ion_heap_query query; };

@@ -83,6 +84,9 @@ long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) break; }

• case ION_IOC_BUFFER_UPDATE:

• ret = ion_buffer_update(data.update.fd, data.update.flags);
  

• break;
  

  case ION_IOC_HEAP_QUERY: ret = ion_query_heaps(&data.query); break;

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 9907332..f1404dc 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -436,6 +436,23 @@ int ion_alloc(size_t len, unsigned int heap_id_mask, unsigned int flags) return fd; } +int ion_buffer_update(unsigned int fd, unsigned int flags) +{

• struct dma_buf *dmabuf;
• struct ion_buffer *buffer;
• dmabuf = dma_buf_get(fd);
• if (!dmabuf)

• return -EINVAL;
  

• buffer = dmabuf->priv;
• buffer->flags = flags;
• dma_buf_put(dmabuf);
• return 0;

+}

• int ion_query_heaps(struct ion_heap_query *query) { struct ion_device *dev = internal_dev;

diff --git a/drivers/staging/android/ion/ion.h b/drivers/staging/android/ion/ion.h index c006fc1..99bf9ab 100644 --- a/drivers/staging/android/ion/ion.h +++ b/drivers/staging/android/ion/ion.h @@ -199,6 +199,7 @@ 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); +int ion_buffer_update(unsigned int fd, unsigned int flags); /**

• ion_heap_init_shrinker

diff --git a/drivers/staging/android/uapi/ion.h b/drivers/staging/android/uapi/ion.h index 5d70098..99753fc 100644 --- a/drivers/staging/android/uapi/ion.h +++ b/drivers/staging/android/uapi/ion.h @@ -74,6 +74,20 @@ struct ion_allocation_data { __u32 unused; }; +/**

• • struct ion_buffer_flag_data - metadata passed from userspace for update
• • buffer flags
• • @fd: file descriptor of the buffer
• • @flags: flags passed to the buffer
• • Provided by userspace as an argument to the ioctl
• */

+struct ion_buffer_flag_data {

• __u32 fd;
• __u32 flags;

+}

• #define MAX_HEAP_NAME 32

/** @@ -116,6 +130,14 @@ struct ion_heap_query { struct ion_allocation_data) /**

• • DOC: ION_IOC_BUFFER_UPDATE - update the specified ion buffer flags
• • Takes an ion_buffer_flag_data structure and returns the result of the
• • buffer flag update operation.
• */

+#define ION_IOC_BUFFER_UPDATE _IOWR(ION_IOC_MAGIC, 1, \

• 		      struct ion_buffer_flag_data)
  

+/**

• DOC: ION_IOC_HEAP_QUERY - information about available heaps
• Takes an ion_heap_query structure and populates information about