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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /include/media/dvb_ringbuffer.h
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Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'include/media/dvb_ringbuffer.h')
-rw-r--r--include/media/dvb_ringbuffer.h280
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diff --git a/include/media/dvb_ringbuffer.h b/include/media/dvb_ringbuffer.h
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+++ b/include/media/dvb_ringbuffer.h
@@ -0,0 +1,280 @@
+/*
+ *
+ * dvb_ringbuffer.h: ring buffer implementation for the dvb driver
+ *
+ * Copyright (C) 2003 Oliver Endriss
+ * Copyright (C) 2004 Andrew de Quincey
+ *
+ * based on code originally found in av7110.c & dvb_ci.c:
+ * Copyright (C) 1999-2003 Ralph Metzler & Marcus Metzler
+ * for convergence integrated media GmbH
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ */
+
+#ifndef _DVB_RINGBUFFER_H_
+#define _DVB_RINGBUFFER_H_
+
+#include <linux/spinlock.h>
+#include <linux/wait.h>
+
+/**
+ * struct dvb_ringbuffer - Describes a ring buffer used at DVB framework
+ *
+ * @data: Area were the ringbuffer data is written
+ * @size: size of the ringbuffer
+ * @pread: next position to read
+ * @pwrite: next position to write
+ * @error: used by ringbuffer clients to indicate that an error happened.
+ * @queue: Wait queue used by ringbuffer clients to indicate when buffer
+ * was filled
+ * @lock: Spinlock used to protect the ringbuffer
+ */
+struct dvb_ringbuffer {
+ u8 *data;
+ ssize_t size;
+ ssize_t pread;
+ ssize_t pwrite;
+ int error;
+
+ wait_queue_head_t queue;
+ spinlock_t lock;
+};
+
+#define DVB_RINGBUFFER_PKTHDRSIZE 3
+
+/**
+ * dvb_ringbuffer_init - initialize ring buffer, lock and queue
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @data: pointer to the buffer where the data will be stored
+ * @len: bytes from ring buffer into @buf
+ */
+extern void dvb_ringbuffer_init(struct dvb_ringbuffer *rbuf, void *data,
+ size_t len);
+
+/**
+ * dvb_ringbuffer_empty - test whether buffer is empty
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ */
+extern int dvb_ringbuffer_empty(struct dvb_ringbuffer *rbuf);
+
+/**
+ * dvb_ringbuffer_free - returns the number of free bytes in the buffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ *
+ * Return: number of free bytes in the buffer
+ */
+extern ssize_t dvb_ringbuffer_free(struct dvb_ringbuffer *rbuf);
+
+/**
+ * dvb_ringbuffer_avail - returns the number of bytes waiting in the buffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ *
+ * Return: number of bytes waiting in the buffer
+ */
+extern ssize_t dvb_ringbuffer_avail(struct dvb_ringbuffer *rbuf);
+
+/**
+ * dvb_ringbuffer_reset - resets the ringbuffer to initial state
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ *
+ * Resets the read and write pointers to zero and flush the buffer.
+ *
+ * This counts as a read and write operation
+ */
+extern void dvb_ringbuffer_reset(struct dvb_ringbuffer *rbuf);
+
+/*
+ * read routines & macros
+ */
+
+/**
+ * dvb_ringbuffer_flush - flush buffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ */
+extern void dvb_ringbuffer_flush(struct dvb_ringbuffer *rbuf);
+
+/**
+ * dvb_ringbuffer_flush_spinlock_wakeup- flush buffer protected by spinlock
+ * and wake-up waiting task(s)
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ */
+extern void dvb_ringbuffer_flush_spinlock_wakeup(struct dvb_ringbuffer *rbuf);
+
+/**
+ * DVB_RINGBUFFER_PEEK - peek at byte @offs in the buffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @offs: offset inside the ringbuffer
+ */
+#define DVB_RINGBUFFER_PEEK(rbuf, offs) \
+ ((rbuf)->data[((rbuf)->pread + (offs)) % (rbuf)->size])
+
+/**
+ * DVB_RINGBUFFER_SKIP - advance read ptr by @num bytes
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @num: number of bytes to advance
+ */
+#define DVB_RINGBUFFER_SKIP(rbuf, num) {\
+ (rbuf)->pread = ((rbuf)->pread + (num)) % (rbuf)->size;\
+}
+
+/**
+ * dvb_ringbuffer_read_user - Reads a buffer into a user pointer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @buf: pointer to the buffer where the data will be stored
+ * @len: bytes from ring buffer into @buf
+ *
+ * This variant assumes that the buffer is a memory at the userspace. So,
+ * it will internally call copy_to_user().
+ *
+ * Return: number of bytes transferred or -EFAULT
+ */
+extern ssize_t dvb_ringbuffer_read_user(struct dvb_ringbuffer *rbuf,
+ u8 __user *buf, size_t len);
+
+/**
+ * dvb_ringbuffer_read - Reads a buffer into a pointer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @buf: pointer to the buffer where the data will be stored
+ * @len: bytes from ring buffer into @buf
+ *
+ * This variant assumes that the buffer is a memory at the Kernel space
+ *
+ * Return: number of bytes transferred or -EFAULT
+ */
+extern void dvb_ringbuffer_read(struct dvb_ringbuffer *rbuf,
+ u8 *buf, size_t len);
+
+/*
+ * write routines & macros
+ */
+
+/**
+ * DVB_RINGBUFFER_WRITE_BYTE - write single byte to ring buffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @byte: byte to write
+ */
+#define DVB_RINGBUFFER_WRITE_BYTE(rbuf, byte) \
+ { (rbuf)->data[(rbuf)->pwrite] = (byte); \
+ (rbuf)->pwrite = ((rbuf)->pwrite + 1) % (rbuf)->size; }
+
+/**
+ * dvb_ringbuffer_write - Writes a buffer into the ringbuffer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @buf: pointer to the buffer where the data will be read
+ * @len: bytes from ring buffer into @buf
+ *
+ * This variant assumes that the buffer is a memory at the Kernel space
+ *
+ * return: number of bytes transferred or -EFAULT
+ */
+extern ssize_t dvb_ringbuffer_write(struct dvb_ringbuffer *rbuf, const u8 *buf,
+ size_t len);
+
+/**
+ * dvb_ringbuffer_write_user - Writes a buffer received via a user pointer
+ *
+ * @rbuf: pointer to struct dvb_ringbuffer
+ * @buf: pointer to the buffer where the data will be read
+ * @len: bytes from ring buffer into @buf
+ *
+ * This variant assumes that the buffer is a memory at the userspace. So,
+ * it will internally call copy_from_user().
+ *
+ * Return: number of bytes transferred or -EFAULT
+ */
+extern ssize_t dvb_ringbuffer_write_user(struct dvb_ringbuffer *rbuf,
+ const u8 __user *buf, size_t len);
+
+/**
+ * dvb_ringbuffer_pkt_write - Write a packet into the ringbuffer.
+ *
+ * @rbuf: Ringbuffer to write to.
+ * @buf: Buffer to write.
+ * @len: Length of buffer (currently limited to 65535 bytes max).
+ *
+ * Return: Number of bytes written, or -EFAULT, -ENOMEM, -EINVAL.
+ */
+extern ssize_t dvb_ringbuffer_pkt_write(struct dvb_ringbuffer *rbuf, u8 *buf,
+ size_t len);
+
+/**
+ * dvb_ringbuffer_pkt_read_user - Read from a packet in the ringbuffer.
+ *
+ * @rbuf: Ringbuffer concerned.
+ * @idx: Packet index as returned by dvb_ringbuffer_pkt_next().
+ * @offset: Offset into packet to read from.
+ * @buf: Destination buffer for data.
+ * @len: Size of destination buffer.
+ *
+ * Return: Number of bytes read, or -EFAULT.
+ *
+ * .. note::
+ *
+ * unlike dvb_ringbuffer_read(), this does **NOT** update the read pointer
+ * in the ringbuffer. You must use dvb_ringbuffer_pkt_dispose() to mark a
+ * packet as no longer required.
+ */
+extern ssize_t dvb_ringbuffer_pkt_read_user(struct dvb_ringbuffer *rbuf,
+ size_t idx,
+ int offset, u8 __user *buf,
+ size_t len);
+
+/**
+ * dvb_ringbuffer_pkt_read - Read from a packet in the ringbuffer.
+ * Note: unlike dvb_ringbuffer_read_user(), this DOES update the read pointer
+ * in the ringbuffer.
+ *
+ * @rbuf: Ringbuffer concerned.
+ * @idx: Packet index as returned by dvb_ringbuffer_pkt_next().
+ * @offset: Offset into packet to read from.
+ * @buf: Destination buffer for data.
+ * @len: Size of destination buffer.
+ *
+ * Return: Number of bytes read, or -EFAULT.
+ */
+extern ssize_t dvb_ringbuffer_pkt_read(struct dvb_ringbuffer *rbuf, size_t idx,
+ int offset, u8 *buf, size_t len);
+
+/**
+ * dvb_ringbuffer_pkt_dispose - Dispose of a packet in the ring buffer.
+ *
+ * @rbuf: Ring buffer concerned.
+ * @idx: Packet index as returned by dvb_ringbuffer_pkt_next().
+ */
+extern void dvb_ringbuffer_pkt_dispose(struct dvb_ringbuffer *rbuf, size_t idx);
+
+/**
+ * dvb_ringbuffer_pkt_next - Get the index of the next packet in a ringbuffer.
+ *
+ * @rbuf: Ringbuffer concerned.
+ * @idx: Previous packet index, or -1 to return the first packet index.
+ * @pktlen: On success, will be updated to contain the length of the packet
+ * in bytes.
+ * returns Packet index (if >=0), or -1 if no packets available.
+ */
+extern ssize_t dvb_ringbuffer_pkt_next(struct dvb_ringbuffer *rbuf,
+ size_t idx, size_t *pktlen);
+
+#endif /* _DVB_RINGBUFFER_H_ */