From patchwork Wed Jul 20 08:43:08 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guennadi Liakhovetski X-Patchwork-Id: 990462 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p6K8hS12024609 for ; Wed, 20 Jul 2011 08:43:28 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751115Ab1GTIn0 (ORCPT ); Wed, 20 Jul 2011 04:43:26 -0400 Received: from moutng.kundenserver.de ([212.227.126.187]:62337 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750745Ab1GTInZ (ORCPT ); Wed, 20 Jul 2011 04:43:25 -0400 Received: from axis700.grange (dslb-178-001-227-112.pools.arcor-ip.net [178.1.227.112]) by mrelayeu.kundenserver.de (node=mrbap2) with ESMTP (Nemesis) id 0M3uUc-1RZdaI3sGY-00qoAL; Wed, 20 Jul 2011 10:43:09 +0200 Received: by axis700.grange (Postfix, from userid 1000) id 5DADD189B6E; Wed, 20 Jul 2011 10:43:08 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by axis700.grange (Postfix) with ESMTP id 4F5D2189B6D; Wed, 20 Jul 2011 10:43:08 +0200 (CEST) Date: Wed, 20 Jul 2011 10:43:08 +0200 (CEST) From: Guennadi Liakhovetski X-X-Sender: lyakh@axis700.grange To: Linux Media Mailing List cc: Sakari Ailus , Sakari Ailus , Laurent Pinchart , Hans Verkuil , Mauro Carvalho Chehab , Pawel Osciak Subject: [PATCH v3] V4L: add two new ioctl()s for multi-size videobuffer management Message-ID: MIME-Version: 1.0 X-Provags-ID: V02:K0:Kta4Hr+vfuDLqO47rPiESOIcFH6W+cEjV4Xa5B7YZIs taH6WIAlbwJOUXQJ3lKPTdcFcrqwbnHMpD8qSD32EdIljOIklE pAZTbUS88W1VUH0jjWzRXHpa68e6NW4q3rAbL27fvm9nrvzNfR 1GqodnL3Q4chwH730nM8mU5wXvMwEoxdZtz8O5G7qkrpnsDcMX dmHw+yyAqVb5ztawR3lJG+wDf9SRKXmzuRqHndRj7w= Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Wed, 20 Jul 2011 08:43:28 +0000 (UTC) A possibility to preallocate and initialise buffers of different sizes in V4L2 is required for an efficient implementation of asnapshot mode. This patch adds two new ioctl()s: VIDIOC_CREATE_BUFS and VIDIOC_PREPARE_BUF and defines respective data structures. Signed-off-by: Guennadi Liakhovetski --- It's been almost a month since v2, the only comments were a request to increase the reserved space in the new ioctl() and to improve documentation. The reserved field is increased in this version, documentation also has been improved in multiple locations. I think, documentation can be further improved at any time, but if there are no objections against the actual contents of this patch, maybe we can commit this version. I still don't see v3.0;-), so, maybe we even can push it for 3.1. A trivial comparison with v2 shows the size of the reserved field as the only change in the API, and the compatibility fix as the only two functional changes. v3: addressed multiple comments by Sakari Ailus 1. increased reserved field in "struct v4l2_create_buffers" to 8 32-bit ints 2. multiple documentation fixes and improvements 3. fixed misplaced "case VIDIOC_PREPARE_BUF" in ioctl 32-bit compatibility processing v2: 1. add preliminary Documentation 2. add flag V4L2_BUFFER_FLAG_NO_CACHE_CLEAN 3. remove VIDIOC_DESTROY_BUFS 4. rename SUBMIT to VIDIOC_PREPARE_BUF 5. add reserved field to struct v4l2_create_buffers 6. cache handling flags moved to struct v4l2_buffer for processing during VIDIOC_PREPARE_BUF 7. VIDIOC_PREPARE_BUF now uses struct v4l2_buffer as its argument Documentation/DocBook/media/v4l/io.xml | 17 +++ Documentation/DocBook/media/v4l/v4l2.xml | 2 + .../DocBook/media/v4l/vidioc-create-bufs.xml | 152 ++++++++++++++++++++ .../DocBook/media/v4l/vidioc-prepare-buf.xml | 96 ++++++++++++ drivers/media/video/v4l2-compat-ioctl32.c | 68 ++++++++- drivers/media/video/v4l2-ioctl.c | 32 ++++ include/linux/videodev2.h | 16 ++ include/media/v4l2-ioctl.h | 2 + 8 files changed, 377 insertions(+), 8 deletions(-) create mode 100644 Documentation/DocBook/media/v4l/vidioc-create-bufs.xml create mode 100644 Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index 227e7ac..6249d0e 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -927,6 +927,23 @@ ioctl is called. Applications set or clear this flag before calling the VIDIOC_QBUF ioctl. + + V4L2_BUF_FLAG_NO_CACHE_INVALIDATE + 0x0400 + Caches do not have to be invalidated for this buffer. +Typically applications shall use this flag, if the data, captured in the buffer +is not going to br touched by the CPU, instead the buffer will, probably, be +passed on to a DMA-capable hardware unit for further processing or output. + + + + V4L2_BUF_FLAG_NO_CACHE_CLEAN + 0x0800 + Caches do not have to be cleaned for this buffer. +Typically applications shall use this flag for output buffers, if the data +in this buffer has not been created by the CPU, but by some DMA-capable unit, +in which case caches have not been used. + diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml index 0d05e87..06bb179 100644 --- a/Documentation/DocBook/media/v4l/v4l2.xml +++ b/Documentation/DocBook/media/v4l/v4l2.xml @@ -462,6 +462,7 @@ and discussions on the V4L mailing list. &sub-close; &sub-ioctl; + &sub-create-bufs; &sub-cropcap; &sub-dbg-g-chip-ident; &sub-dbg-g-register; @@ -504,6 +505,7 @@ and discussions on the V4L mailing list. &sub-queryctrl; &sub-query-dv-preset; &sub-querystd; + &sub-prepare-buf; &sub-reqbufs; &sub-s-hw-freq-seek; &sub-streamon; diff --git a/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml b/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml new file mode 100644 index 0000000..5f0158c --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml @@ -0,0 +1,152 @@ + + + ioctl VIDIOC_CREATE_BUFS + &manvol; + + + + VIDIOC_CREATE_BUFS + Create buffers for Memory Mapped or User Pointer I/O + + + + + + int ioctl + int fd + int request + struct v4l2_create_buffers *argp + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_CREATE_BUFS + + + + argp + + + + + + + + + Description + + This ioctl is used to create buffers for memory +mapped or user pointer +I/O. It can be used as an alternative to the VIDIOC_REQBUFS +ioctl, when a tighter control over buffers is required. This ioctl can be called +multiple times to create buffers of different sizes. + + To allocate device buffers applications initialize all +fields of the v4l2_create_buffers structure. +They set the type field in the +v4l2_format structure, embedded in this +structure, to the respective stream or buffer type. +count must be set to the number of required +buffers. memory specifies the required I/O +method. Applications have two possibilities to specify the size of buffers +to be prepared: they can either set the size +field explicitly to a non-zero value, or fill in the frame format data in the +format field. In the latter case buffer sizes +will be calculated automatically by the driver. The +reserved array must be zeroed. When the ioctl +is called with a pointer to this structure the driver will attempt to allocate +up to the requested number of buffers and store the actual number allocated +and the starting index in the count and +the index fields respectively. +count can be smaller than the number requested. +-ENOMEM is returned, if the driver runs out of free memory. + When the I/O method is not supported the ioctl +returns an &EINVAL;. + + + struct <structname>v4l2_create_buffers</structname> + + &cs-str; + + + __u32 + index + The starting buffer index, returned by the driver. + + + __u32 + count + The number of buffers requested or granted. + + + &v4l2-memory; + memory + Applications set this field to +V4L2_MEMORY_MMAP or +V4L2_MEMORY_USERPTR. + + + __u32 + size + Explicit size of buffers, being created. + + + &v4l2-format; + format + Application has to set the type +field, other fields should be used, if the application wants to allocate buffers +for a specific frame format. + + + __u32 + reserved[8] + A place holder for future extensions. + + + +
+ + + + &return-value; + + + + ENOMEM + + No memory to allocate buffers for memory +mapped I/O. + + + + EINVAL + + The buffer type (type field) or the +requested I/O method (memory) is not +supported. + + + + + + + diff --git a/Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml b/Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml new file mode 100644 index 0000000..509e752 --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-prepare-buf.xml @@ -0,0 +1,96 @@ + + + ioctl VIDIOC_PREPARE_BUF + &manvol; + + + + VIDIOC_PREPARE_BUF + Prepare a buffer for I/O + + + + + + int ioctl + int fd + int request + struct v4l2_buffer *argp + + + + + + Arguments + + + + fd + + &fd; + + + + request + + VIDIOC_PREPARE_BUF + + + + argp + + + + + + + + + Description + + Applications can optionally call the +VIDIOC_PREPARE_BUF ioctl to pass ownership of the buffer +to the driver before actually enqueuing it, using the +VIDIOC_QBUF ioctl, and to prepare it for future I/O. +Such preparations may include cache invalidation or cleaning. Performing them +in advance saves time during the actual I/O. In case such cache operations are +not required, the application can use one of +V4L2_BUF_FLAG_NO_CACHE_INVALIDATE and +V4L2_BUF_FLAG_NO_CACHE_CLEAN flags to skip the respective +step. + + The v4l2_buffer structure is +specified in . + + + + &return-value; + + + + EBUSY + + File I/O is in progress. + + + + EINVAL + + The buffer type is not +supported, or the index is out of bounds, +or no buffers have been allocated yet, or the +userptr or +length are invalid. + + + + + + + diff --git a/drivers/media/video/v4l2-compat-ioctl32.c b/drivers/media/video/v4l2-compat-ioctl32.c index 61979b7..4105f69 100644 --- a/drivers/media/video/v4l2-compat-ioctl32.c +++ b/drivers/media/video/v4l2-compat-ioctl32.c @@ -159,11 +159,16 @@ struct v4l2_format32 { } fmt; }; -static int get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user *up) +struct v4l2_create_buffers32 { + __u32 index; /* output: buffers index...index + count - 1 have been created */ + __u32 count; + enum v4l2_memory memory; + __u32 size; /* Explicit size, e.g., for compressed streams */ + struct v4l2_format32 format; /* "type" is used always, the rest if size == 0 */ +}; + +static int __get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user *up) { - if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_format32)) || - get_user(kp->type, &up->type)) - return -EFAULT; switch (kp->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: case V4L2_BUF_TYPE_VIDEO_OUTPUT: @@ -192,11 +197,24 @@ static int get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user } } -static int put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user *up) +static int get_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user *up) +{ + if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_format32)) || + get_user(kp->type, &up->type)) + return -EFAULT; + return __get_v4l2_format32(kp, up); +} + +static int get_v4l2_create32(struct v4l2_create_buffers *kp, struct v4l2_create_buffers32 __user *up) +{ + if (!access_ok(VERIFY_READ, up, sizeof(struct v4l2_create_buffers32)) || + copy_from_user(kp, up, offsetof(struct v4l2_create_buffers32, format.fmt))) + return -EFAULT; + return __get_v4l2_format32(&kp->format, &up->format); +} + +static int __put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user *up) { - if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_format32)) || - put_user(kp->type, &up->type)) - return -EFAULT; switch (kp->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: case V4L2_BUF_TYPE_VIDEO_OUTPUT: @@ -225,6 +243,22 @@ static int put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user } } +static int put_v4l2_format32(struct v4l2_format *kp, struct v4l2_format32 __user *up) +{ + if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_format32)) || + put_user(kp->type, &up->type)) + return -EFAULT; + return __put_v4l2_format32(kp, up); +} + +static int put_v4l2_create32(struct v4l2_create_buffers *kp, struct v4l2_create_buffers32 __user *up) +{ + if (!access_ok(VERIFY_WRITE, up, sizeof(struct v4l2_create_buffers32)) || + copy_to_user(up, kp, offsetof(struct v4l2_create_buffers32, format.fmt))) + return -EFAULT; + return __put_v4l2_format32(&kp->format, &up->format); +} + struct v4l2_standard32 { __u32 index; __u32 id[2]; /* __u64 would get the alignment wrong */ @@ -702,6 +736,8 @@ static int put_v4l2_event32(struct v4l2_event *kp, struct v4l2_event32 __user *u #define VIDIOC_S_EXT_CTRLS32 _IOWR('V', 72, struct v4l2_ext_controls32) #define VIDIOC_TRY_EXT_CTRLS32 _IOWR('V', 73, struct v4l2_ext_controls32) #define VIDIOC_DQEVENT32 _IOR ('V', 89, struct v4l2_event32) +#define VIDIOC_CREATE_BUFS32 _IOWR('V', 92, struct v4l2_create_buffers32) +#define VIDIOC_PREPARE_BUF32 _IOWR('V', 93, struct v4l2_buffer32) #define VIDIOC_OVERLAY32 _IOW ('V', 14, s32) #define VIDIOC_STREAMON32 _IOW ('V', 18, s32) @@ -721,6 +757,7 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar struct v4l2_standard v2s; struct v4l2_ext_controls v2ecs; struct v4l2_event v2ev; + struct v4l2_create_buffers v2crt; unsigned long vx; int vi; } karg; @@ -751,6 +788,8 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar case VIDIOC_S_INPUT32: cmd = VIDIOC_S_INPUT; break; case VIDIOC_G_OUTPUT32: cmd = VIDIOC_G_OUTPUT; break; case VIDIOC_S_OUTPUT32: cmd = VIDIOC_S_OUTPUT; break; + case VIDIOC_CREATE_BUFS32: cmd = VIDIOC_CREATE_BUFS; break; + case VIDIOC_PREPARE_BUF32: cmd = VIDIOC_PREPARE_BUF; break; } switch (cmd) { @@ -775,6 +814,12 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar compatible_arg = 0; break; + case VIDIOC_CREATE_BUFS: + err = get_v4l2_create32(&karg.v2crt, up); + compatible_arg = 0; + break; + + case VIDIOC_PREPARE_BUF: case VIDIOC_QUERYBUF: case VIDIOC_QBUF: case VIDIOC_DQBUF: @@ -860,6 +905,11 @@ static long do_video_ioctl(struct file *file, unsigned int cmd, unsigned long ar err = put_v4l2_format32(&karg.v2f, up); break; + case VIDIOC_CREATE_BUFS: + err = put_v4l2_create32(&karg.v2crt, up); + break; + + case VIDIOC_PREPARE_BUF: case VIDIOC_QUERYBUF: case VIDIOC_QBUF: case VIDIOC_DQBUF: @@ -959,6 +1009,8 @@ long v4l2_compat_ioctl32(struct file *file, unsigned int cmd, unsigned long arg) case VIDIOC_DQEVENT32: case VIDIOC_SUBSCRIBE_EVENT: case VIDIOC_UNSUBSCRIBE_EVENT: + case VIDIOC_CREATE_BUFS32: + case VIDIOC_PREPARE_BUF32: ret = do_video_ioctl(file, cmd, arg); break; diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c index 002ce13..7824152 100644 --- a/drivers/media/video/v4l2-ioctl.c +++ b/drivers/media/video/v4l2-ioctl.c @@ -260,6 +260,8 @@ static const char *v4l2_ioctls[] = { [_IOC_NR(VIDIOC_DQEVENT)] = "VIDIOC_DQEVENT", [_IOC_NR(VIDIOC_SUBSCRIBE_EVENT)] = "VIDIOC_SUBSCRIBE_EVENT", [_IOC_NR(VIDIOC_UNSUBSCRIBE_EVENT)] = "VIDIOC_UNSUBSCRIBE_EVENT", + [_IOC_NR(VIDIOC_CREATE_BUFS)] = "VIDIOC_CREATE_BUFS", + [_IOC_NR(VIDIOC_PREPARE_BUF)] = "VIDIOC_PREPARE_BUF", }; #define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls) @@ -2216,6 +2218,36 @@ static long __video_do_ioctl(struct file *file, dbgarg(cmd, "type=0x%8.8x", sub->type); break; } + case VIDIOC_CREATE_BUFS: + { + struct v4l2_create_buffers *create = arg; + + if (!ops->vidioc_create_bufs) + break; + ret = check_fmt(ops, create->format.type); + if (ret) + break; + + if (create->size) + CLEAR_AFTER_FIELD(create, count); + + ret = ops->vidioc_create_bufs(file, fh, create); + + dbgarg(cmd, "count=%d\n", create->count); + break; + } + case VIDIOC_PREPARE_BUF: + { + struct v4l2_buffer *b = arg; + + if (!ops->vidioc_prepare_buf) + break; + + ret = ops->vidioc_prepare_buf(file, fh, b); + + dbgarg(cmd, "index=%d", b->index); + break; + } default: { bool valid_prio = true; diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index fca24cc..0b594c7 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -653,6 +653,9 @@ struct v4l2_buffer { #define V4L2_BUF_FLAG_ERROR 0x0040 #define V4L2_BUF_FLAG_TIMECODE 0x0100 /* timecode field is valid */ #define V4L2_BUF_FLAG_INPUT 0x0200 /* input field is valid */ +/* Cache handling flags */ +#define V4L2_BUF_FLAG_NO_CACHE_INVALIDATE 0x0400 +#define V4L2_BUF_FLAG_NO_CACHE_CLEAN 0x0800 /* * O V E R L A Y P R E V I E W @@ -2092,6 +2095,16 @@ struct v4l2_dbg_chip_ident { __u32 revision; /* chip revision, chip specific */ } __attribute__ ((packed)); +/* VIDIOC_CREATE_BUFS */ +struct v4l2_create_buffers { + __u32 index; /* output: buffers index...index + count - 1 have been created */ + __u32 count; + enum v4l2_memory memory; + __u32 size; /* Explicit size, e.g., for compressed streams */ + struct v4l2_format format; /* "type" is used always, the rest if size == 0 */ + __u32 reserved[8]; +}; + /* * I O C T L C O D E S F O R V I D E O D E V I C E S * @@ -2182,6 +2195,9 @@ struct v4l2_dbg_chip_ident { #define VIDIOC_SUBSCRIBE_EVENT _IOW('V', 90, struct v4l2_event_subscription) #define VIDIOC_UNSUBSCRIBE_EVENT _IOW('V', 91, struct v4l2_event_subscription) +#define VIDIOC_CREATE_BUFS _IOWR('V', 92, struct v4l2_create_buffers) +#define VIDIOC_PREPARE_BUF _IOW('V', 93, struct v4l2_buffer) + /* Reminder: when adding new ioctls please add support for them to drivers/media/video/v4l2-compat-ioctl32.c as well! */ diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h index dd9f1e7..4d1c74a 100644 --- a/include/media/v4l2-ioctl.h +++ b/include/media/v4l2-ioctl.h @@ -122,6 +122,8 @@ struct v4l2_ioctl_ops { int (*vidioc_qbuf) (struct file *file, void *fh, struct v4l2_buffer *b); int (*vidioc_dqbuf) (struct file *file, void *fh, struct v4l2_buffer *b); + int (*vidioc_create_bufs)(struct file *file, void *fh, struct v4l2_create_buffers *b); + int (*vidioc_prepare_buf)(struct file *file, void *fh, struct v4l2_buffer *b); int (*vidioc_overlay) (struct file *file, void *fh, unsigned int i); int (*vidioc_g_fbuf) (struct file *file, void *fh,