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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /include/media/dvb_ringbuffer.h | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'include/media/dvb_ringbuffer.h')
| -rw-r--r-- | include/media/dvb_ringbuffer.h | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/include/media/dvb_ringbuffer.h b/include/media/dvb_ringbuffer.h new file mode 100644 index 000000000..029c8b615 --- /dev/null +++ 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_ */ |
