Messages in this thread | | | Subject | Re: [PATCH] staging: android: ion: add buffer flag update ioctl | From | Laura Abbott <> | Date | Wed, 19 Dec 2018 10:09:30 -0800 |
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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 >
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