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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /net/rds/ib_ring.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
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 'net/rds/ib_ring.c')
| -rw-r--r-- | net/rds/ib_ring.c | 168 |
1 files changed, 168 insertions, 0 deletions
diff --git a/net/rds/ib_ring.c b/net/rds/ib_ring.c new file mode 100644 index 000000000..006b2e441 --- /dev/null +++ b/net/rds/ib_ring.c @@ -0,0 +1,168 @@ +/* + * Copyright (c) 2006 Oracle. All rights reserved. + * + * This software is available to you under a choice of one of two + * licenses. You may choose to be licensed under the terms of the GNU + * General Public License (GPL) Version 2, available from the file + * COPYING in the main directory of this source tree, or the + * OpenIB.org BSD license below: + * + * Redistribution and use in source and binary forms, with or + * without modification, are permitted provided that the following + * conditions are met: + * + * - Redistributions of source code must retain the above + * copyright notice, this list of conditions and the following + * disclaimer. + * + * - Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following + * disclaimer in the documentation and/or other materials + * provided with the distribution. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + */ +#include <linux/kernel.h> + +#include "rds.h" +#include "ib.h" + +/* + * Locking for IB rings. + * We assume that allocation is always protected by a mutex + * in the caller (this is a valid assumption for the current + * implementation). + * + * Freeing always happens in an interrupt, and hence only + * races with allocations, but not with other free()s. + * + * The interaction between allocation and freeing is that + * the alloc code has to determine the number of free entries. + * To this end, we maintain two counters; an allocation counter + * and a free counter. Both are allowed to run freely, and wrap + * around. + * The number of used entries is always (alloc_ctr - free_ctr) % NR. + * + * The current implementation makes free_ctr atomic. When the + * caller finds an allocation fails, it should set an "alloc fail" + * bit and retry the allocation. The "alloc fail" bit essentially tells + * the CQ completion handlers to wake it up after freeing some + * more entries. + */ + +/* + * This only happens on shutdown. + */ +DECLARE_WAIT_QUEUE_HEAD(rds_ib_ring_empty_wait); + +void rds_ib_ring_init(struct rds_ib_work_ring *ring, u32 nr) +{ + memset(ring, 0, sizeof(*ring)); + ring->w_nr = nr; + rdsdebug("ring %p nr %u\n", ring, ring->w_nr); +} + +static inline u32 __rds_ib_ring_used(struct rds_ib_work_ring *ring) +{ + u32 diff; + + /* This assumes that atomic_t has at least as many bits as u32 */ + diff = ring->w_alloc_ctr - (u32) atomic_read(&ring->w_free_ctr); + BUG_ON(diff > ring->w_nr); + + return diff; +} + +void rds_ib_ring_resize(struct rds_ib_work_ring *ring, u32 nr) +{ + /* We only ever get called from the connection setup code, + * prior to creating the QP. */ + BUG_ON(__rds_ib_ring_used(ring)); + ring->w_nr = nr; +} + +static int __rds_ib_ring_empty(struct rds_ib_work_ring *ring) +{ + return __rds_ib_ring_used(ring) == 0; +} + +u32 rds_ib_ring_alloc(struct rds_ib_work_ring *ring, u32 val, u32 *pos) +{ + u32 ret = 0, avail; + + avail = ring->w_nr - __rds_ib_ring_used(ring); + + rdsdebug("ring %p val %u next %u free %u\n", ring, val, + ring->w_alloc_ptr, avail); + + if (val && avail) { + ret = min(val, avail); + *pos = ring->w_alloc_ptr; + + ring->w_alloc_ptr = (ring->w_alloc_ptr + ret) % ring->w_nr; + ring->w_alloc_ctr += ret; + } + + return ret; +} + +void rds_ib_ring_free(struct rds_ib_work_ring *ring, u32 val) +{ + ring->w_free_ptr = (ring->w_free_ptr + val) % ring->w_nr; + atomic_add(val, &ring->w_free_ctr); + + if (__rds_ib_ring_empty(ring) && + waitqueue_active(&rds_ib_ring_empty_wait)) + wake_up(&rds_ib_ring_empty_wait); +} + +void rds_ib_ring_unalloc(struct rds_ib_work_ring *ring, u32 val) +{ + ring->w_alloc_ptr = (ring->w_alloc_ptr - val) % ring->w_nr; + ring->w_alloc_ctr -= val; +} + +int rds_ib_ring_empty(struct rds_ib_work_ring *ring) +{ + return __rds_ib_ring_empty(ring); +} + +int rds_ib_ring_low(struct rds_ib_work_ring *ring) +{ + return __rds_ib_ring_used(ring) <= (ring->w_nr >> 1); +} + +/* + * returns the oldest allocated ring entry. This will be the next one + * freed. This can't be called if there are none allocated. + */ +u32 rds_ib_ring_oldest(struct rds_ib_work_ring *ring) +{ + return ring->w_free_ptr; +} + +/* + * returns the number of completed work requests. + */ + +u32 rds_ib_ring_completed(struct rds_ib_work_ring *ring, u32 wr_id, u32 oldest) +{ + u32 ret; + + if (oldest <= (unsigned long long)wr_id) + ret = (unsigned long long)wr_id - oldest + 1; + else + ret = ring->w_nr - oldest + (unsigned long long)wr_id + 1; + + rdsdebug("ring %p ret %u wr_id %u oldest %u\n", ring, ret, + wr_id, oldest); + return ret; +} |
