From cd9fd6f12fc762246607c77673acdfb55f8096b6 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Wed, 5 Dec 2018 06:36:13 -0500 Subject: media: extended-controls.rst: add note to the MPEG2 state controls Add a note mentioning that these two controls are not part of the public API while they still stabilizing. Signed-off-by: Hans Verkuil Reviewed-by: Paul Kocialkowski Signed-off-by: Mauro Carvalho Chehab --- Documentation/media/uapi/v4l/extended-controls.rst | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'Documentation') diff --git a/Documentation/media/uapi/v4l/extended-controls.rst b/Documentation/media/uapi/v4l/extended-controls.rst index 65a1d873196b..027358b91082 100644 --- a/Documentation/media/uapi/v4l/extended-controls.rst +++ b/Documentation/media/uapi/v4l/extended-controls.rst @@ -1505,6 +1505,11 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - configuring a stateless hardware decoding pipeline for MPEG-2. The bitstream parameters are defined according to :ref:`mpeg2part2`. + .. note:: + + This compound control is not yet part of the public kernel API and + it is expected to change. + .. c:type:: v4l2_ctrl_mpeg2_slice_params .. cssclass:: longtable @@ -1625,6 +1630,11 @@ enum v4l2_mpeg_video_h264_hierarchical_coding_type - Specifies quantization matrices (as extracted from the bitstream) for the associated MPEG-2 slice data. + .. note:: + + This compound control is not yet part of the public kernel API and + it is expected to change. + .. c:type:: v4l2_ctrl_mpeg2_quantization .. cssclass:: longtable -- cgit v1.2.3 From 55f3f7eab75c10d9b33d122670b5935ab64db50f Mon Sep 17 00:00:00 2001 From: Matthew Wilcox Date: Mon, 26 Nov 2018 16:08:43 -0500 Subject: XArray: Add xa_cmpxchg_irq and xa_cmpxchg_bh These convenience wrappers match the other _irq and _bh wrappers we already have. It turns out I'd already open-coded xa_cmpxchg_irq() in the shmem code, so convert that. Signed-off-by: Matthew Wilcox --- Documentation/core-api/xarray.rst | 5 +++- include/linux/xarray.h | 54 +++++++++++++++++++++++++++++++++++++++ mm/shmem.c | 4 +-- 3 files changed, 59 insertions(+), 4 deletions(-) (limited to 'Documentation') diff --git a/Documentation/core-api/xarray.rst b/Documentation/core-api/xarray.rst index dbe96cb5558e..6a6d67acaf69 100644 --- a/Documentation/core-api/xarray.rst +++ b/Documentation/core-api/xarray.rst @@ -187,6 +187,8 @@ Takes xa_lock internally: * :c:func:`xa_erase_bh` * :c:func:`xa_erase_irq` * :c:func:`xa_cmpxchg` + * :c:func:`xa_cmpxchg_bh` + * :c:func:`xa_cmpxchg_irq` * :c:func:`xa_store_range` * :c:func:`xa_alloc` * :c:func:`xa_alloc_bh` @@ -263,7 +265,8 @@ using :c:func:`xa_lock_irqsave` in both the interrupt handler and process context, or :c:func:`xa_lock_irq` in process context and :c:func:`xa_lock` in the interrupt handler. Some of the more common patterns have helper functions such as :c:func:`xa_store_bh`, :c:func:`xa_store_irq`, -:c:func:`xa_erase_bh` and :c:func:`xa_erase_irq`. +:c:func:`xa_erase_bh`, :c:func:`xa_erase_irq`, :c:func:`xa_cmpxchg_bh` +and :c:func:`xa_cmpxchg_irq`. Sometimes you need to protect access to the XArray with a mutex because that lock sits above another mutex in the locking hierarchy. That does diff --git a/include/linux/xarray.h b/include/linux/xarray.h index 564892e19f8c..f492e21c4aa2 100644 --- a/include/linux/xarray.h +++ b/include/linux/xarray.h @@ -553,6 +553,60 @@ static inline void *xa_cmpxchg(struct xarray *xa, unsigned long index, return curr; } +/** + * xa_cmpxchg_bh() - Conditionally replace an entry in the XArray. + * @xa: XArray. + * @index: Index into array. + * @old: Old value to test against. + * @entry: New value to place in array. + * @gfp: Memory allocation flags. + * + * This function is like calling xa_cmpxchg() except it disables softirqs + * while holding the array lock. + * + * Context: Any context. Takes and releases the xa_lock while + * disabling softirqs. May sleep if the @gfp flags permit. + * Return: The old value at this index or xa_err() if an error happened. + */ +static inline void *xa_cmpxchg_bh(struct xarray *xa, unsigned long index, + void *old, void *entry, gfp_t gfp) +{ + void *curr; + + xa_lock_bh(xa); + curr = __xa_cmpxchg(xa, index, old, entry, gfp); + xa_unlock_bh(xa); + + return curr; +} + +/** + * xa_cmpxchg_irq() - Conditionally replace an entry in the XArray. + * @xa: XArray. + * @index: Index into array. + * @old: Old value to test against. + * @entry: New value to place in array. + * @gfp: Memory allocation flags. + * + * This function is like calling xa_cmpxchg() except it disables interrupts + * while holding the array lock. + * + * Context: Process context. Takes and releases the xa_lock while + * disabling interrupts. May sleep if the @gfp flags permit. + * Return: The old value at this index or xa_err() if an error happened. + */ +static inline void *xa_cmpxchg_irq(struct xarray *xa, unsigned long index, + void *old, void *entry, gfp_t gfp) +{ + void *curr; + + xa_lock_irq(xa); + curr = __xa_cmpxchg(xa, index, old, entry, gfp); + xa_unlock_irq(xa); + + return curr; +} + /** * xa_insert() - Store this entry in the XArray unless another entry is * already present. diff --git a/mm/shmem.c b/mm/shmem.c index cddc72ac44d8..6adbdd349875 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -661,9 +661,7 @@ static int shmem_free_swap(struct address_space *mapping, { void *old; - xa_lock_irq(&mapping->i_pages); - old = __xa_cmpxchg(&mapping->i_pages, index, radswap, NULL, 0); - xa_unlock_irq(&mapping->i_pages); + old = xa_cmpxchg_irq(&mapping->i_pages, index, radswap, NULL, 0); if (old != radswap) return -ENOENT; free_swap_and_cache(radix_to_swp_entry(radswap)); -- cgit v1.2.3