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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 /io_uring/napi.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 'io_uring/napi.c')
| -rw-r--r-- | io_uring/napi.c | 411 |
1 files changed, 411 insertions, 0 deletions
diff --git a/io_uring/napi.c b/io_uring/napi.c new file mode 100644 index 000000000..bfc771445 --- /dev/null +++ b/io_uring/napi.c @@ -0,0 +1,411 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include "io_uring.h" +#include "napi.h" + +#ifdef CONFIG_NET_RX_BUSY_POLL + +/* Timeout for cleanout of stale entries. */ +#define NAPI_TIMEOUT (60 * SEC_CONVERSION) + +struct io_napi_entry { + unsigned int napi_id; + struct list_head list; + + unsigned long timeout; + struct hlist_node node; + + struct rcu_head rcu; +}; + +static struct io_napi_entry *io_napi_hash_find(struct hlist_head *hash_list, + unsigned int napi_id) +{ + struct io_napi_entry *e; + + hlist_for_each_entry_rcu(e, hash_list, node) { + if (e->napi_id != napi_id) + continue; + return e; + } + + return NULL; +} + +static inline ktime_t net_to_ktime(unsigned long t) +{ + /* napi approximating usecs, reverse busy_loop_current_time */ + return ns_to_ktime(t << 10); +} + +int __io_napi_add_id(struct io_ring_ctx *ctx, unsigned int napi_id, + unsigned int mode) +{ + struct hlist_head *hash_list; + struct io_napi_entry *e; + + /* Non-NAPI IDs can be rejected. */ + if (!napi_id_valid(napi_id)) + return -EINVAL; + + hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))]; + + scoped_guard(rcu) { + e = io_napi_hash_find(hash_list, napi_id); + if (e) { + WRITE_ONCE(e->timeout, jiffies + NAPI_TIMEOUT); + return -EEXIST; + } + } + + e = kmalloc(sizeof(*e), GFP_NOWAIT); + if (!e) + return -ENOMEM; + + e->napi_id = napi_id; + e->timeout = jiffies + NAPI_TIMEOUT; + + /* + * guard(spinlock) is not used to manually unlock it before calling + * kfree() + */ + spin_lock(&ctx->napi_lock); + if (unlikely(READ_ONCE(ctx->napi_track_mode) != mode)) { + spin_unlock(&ctx->napi_lock); + kfree(e); + return -EINVAL; + } + if (unlikely(io_napi_hash_find(hash_list, napi_id))) { + spin_unlock(&ctx->napi_lock); + kfree(e); + return -EEXIST; + } + + hlist_add_tail_rcu(&e->node, hash_list); + list_add_tail_rcu(&e->list, &ctx->napi_list); + spin_unlock(&ctx->napi_lock); + return 0; +} + +static int __io_napi_del_id(struct io_ring_ctx *ctx, unsigned int napi_id) +{ + struct hlist_head *hash_list; + struct io_napi_entry *e; + + /* Non-NAPI IDs can be rejected. */ + if (!napi_id_valid(napi_id)) + return -EINVAL; + + hash_list = &ctx->napi_ht[hash_min(napi_id, HASH_BITS(ctx->napi_ht))]; + guard(spinlock)(&ctx->napi_lock); + e = io_napi_hash_find(hash_list, napi_id); + if (!e) + return -ENOENT; + + list_del_rcu(&e->list); + hash_del_rcu(&e->node); + kfree_rcu(e, rcu); + return 0; +} + +static void __io_napi_remove_stale(struct io_ring_ctx *ctx) +{ + struct io_napi_entry *e; + + guard(spinlock)(&ctx->napi_lock); + /* + * list_for_each_entry_safe() is not required as long as: + * 1. list_del_rcu() does not reset the deleted node next pointer + * 2. kfree_rcu() delays the memory freeing until the next quiescent + * state + */ + list_for_each_entry(e, &ctx->napi_list, list) { + if (time_after(jiffies, READ_ONCE(e->timeout))) { + list_del_rcu(&e->list); + hash_del_rcu(&e->node); + kfree_rcu(e, rcu); + } + } +} + +static inline void io_napi_remove_stale(struct io_ring_ctx *ctx, bool is_stale) +{ + if (is_stale) + __io_napi_remove_stale(ctx); +} + +static inline bool io_napi_busy_loop_timeout(ktime_t start_time, + ktime_t bp) +{ + if (bp) { + ktime_t end_time = ktime_add(start_time, bp); + ktime_t now = net_to_ktime(busy_loop_current_time()); + + return ktime_after(now, end_time); + } + + return true; +} + +static bool io_napi_busy_loop_should_end(void *data, + unsigned long start_time) +{ + struct io_wait_queue *iowq = data; + + if (signal_pending(current)) + return true; + if (io_should_wake(iowq) || io_has_work(iowq->ctx)) + return true; + if (io_napi_busy_loop_timeout(net_to_ktime(start_time), + iowq->napi_busy_poll_dt)) + return true; + + return false; +} + +/* + * never report stale entries + */ +static bool static_tracking_do_busy_loop(struct io_ring_ctx *ctx, + bool (*loop_end)(void *, unsigned long), + void *loop_end_arg) +{ + struct io_napi_entry *e; + + list_for_each_entry_rcu(e, &ctx->napi_list, list) + napi_busy_loop_rcu(e->napi_id, loop_end, loop_end_arg, + ctx->napi_prefer_busy_poll, BUSY_POLL_BUDGET); + return false; +} + +static bool +dynamic_tracking_do_busy_loop(struct io_ring_ctx *ctx, + bool (*loop_end)(void *, unsigned long), + void *loop_end_arg) +{ + struct io_napi_entry *e; + bool is_stale = false; + + list_for_each_entry_rcu(e, &ctx->napi_list, list) { + napi_busy_loop_rcu(e->napi_id, loop_end, loop_end_arg, + ctx->napi_prefer_busy_poll, BUSY_POLL_BUDGET); + + if (time_after(jiffies, READ_ONCE(e->timeout))) + is_stale = true; + } + + return is_stale; +} + +static inline bool +__io_napi_do_busy_loop(struct io_ring_ctx *ctx, + bool (*loop_end)(void *, unsigned long), + void *loop_end_arg) +{ + switch (READ_ONCE(ctx->napi_track_mode)) { + case IO_URING_NAPI_TRACKING_STATIC: + return static_tracking_do_busy_loop(ctx, loop_end, loop_end_arg); + case IO_URING_NAPI_TRACKING_DYNAMIC: + return dynamic_tracking_do_busy_loop(ctx, loop_end, loop_end_arg); + default: + return false; + } +} + +static void io_napi_blocking_busy_loop(struct io_ring_ctx *ctx, + struct io_wait_queue *iowq) +{ + unsigned long start_time = busy_loop_current_time(); + bool (*loop_end)(void *, unsigned long) = NULL; + void *loop_end_arg = NULL; + bool is_stale = false; + + /* Singular lists use a different napi loop end check function and are + * only executed once. + */ + if (list_is_singular(&ctx->napi_list)) { + loop_end = io_napi_busy_loop_should_end; + loop_end_arg = iowq; + } + + scoped_guard(rcu) { + do { + is_stale = __io_napi_do_busy_loop(ctx, loop_end, + loop_end_arg); + } while (!io_napi_busy_loop_should_end(iowq, start_time) && + !loop_end_arg); + } + + io_napi_remove_stale(ctx, is_stale); +} + +/* + * io_napi_init() - Init napi settings + * @ctx: pointer to io-uring context structure + * + * Init napi settings in the io-uring context. + */ +void io_napi_init(struct io_ring_ctx *ctx) +{ + u64 sys_dt = READ_ONCE(sysctl_net_busy_poll) * NSEC_PER_USEC; + + INIT_LIST_HEAD(&ctx->napi_list); + spin_lock_init(&ctx->napi_lock); + ctx->napi_prefer_busy_poll = false; + ctx->napi_busy_poll_dt = ns_to_ktime(sys_dt); + ctx->napi_track_mode = IO_URING_NAPI_TRACKING_INACTIVE; +} + +/* + * io_napi_free() - Deallocate napi + * @ctx: pointer to io-uring context structure + * + * Free the napi list and the hash table in the io-uring context. + */ +void io_napi_free(struct io_ring_ctx *ctx) +{ + struct io_napi_entry *e; + + guard(spinlock)(&ctx->napi_lock); + list_for_each_entry(e, &ctx->napi_list, list) { + hash_del_rcu(&e->node); + kfree_rcu(e, rcu); + } + INIT_LIST_HEAD_RCU(&ctx->napi_list); +} + +static int io_napi_register_napi(struct io_ring_ctx *ctx, + struct io_uring_napi *napi) +{ + switch (napi->op_param) { + case IO_URING_NAPI_TRACKING_DYNAMIC: + case IO_URING_NAPI_TRACKING_STATIC: + break; + default: + return -EINVAL; + } + WRITE_ONCE(ctx->napi_track_mode, IO_URING_NAPI_TRACKING_INACTIVE); + io_napi_free(ctx); + /* cap NAPI at 10 msec of spin time */ + napi->busy_poll_to = min(10000, napi->busy_poll_to); + WRITE_ONCE(ctx->napi_busy_poll_dt, napi->busy_poll_to * NSEC_PER_USEC); + WRITE_ONCE(ctx->napi_prefer_busy_poll, !!napi->prefer_busy_poll); + WRITE_ONCE(ctx->napi_track_mode, napi->op_param); + return 0; +} + +/* + * io_napi_register() - Register napi with io-uring + * @ctx: pointer to io-uring context structure + * @arg: pointer to io_uring_napi structure + * + * Register napi in the io-uring context. + */ +int io_register_napi(struct io_ring_ctx *ctx, void __user *arg) +{ + const struct io_uring_napi curr = { + .busy_poll_to = ktime_to_us(ctx->napi_busy_poll_dt), + .prefer_busy_poll = ctx->napi_prefer_busy_poll, + .op_param = ctx->napi_track_mode + }; + struct io_uring_napi napi; + + if (ctx->flags & IORING_SETUP_IOPOLL) + return -EINVAL; + if (copy_from_user(&napi, arg, sizeof(napi))) + return -EFAULT; + if (napi.pad[0] || napi.pad[1] || napi.resv) + return -EINVAL; + + if (copy_to_user(arg, &curr, sizeof(curr))) + return -EFAULT; + + switch (napi.opcode) { + case IO_URING_NAPI_REGISTER_OP: + return io_napi_register_napi(ctx, &napi); + case IO_URING_NAPI_STATIC_ADD_ID: + if (curr.op_param != IO_URING_NAPI_TRACKING_STATIC) + return -EINVAL; + return __io_napi_add_id(ctx, napi.op_param, + IO_URING_NAPI_TRACKING_STATIC); + case IO_URING_NAPI_STATIC_DEL_ID: + if (curr.op_param != IO_URING_NAPI_TRACKING_STATIC) + return -EINVAL; + return __io_napi_del_id(ctx, napi.op_param); + default: + return -EINVAL; + } +} + +/* + * io_napi_unregister() - Unregister napi with io-uring + * @ctx: pointer to io-uring context structure + * @arg: pointer to io_uring_napi structure + * + * Unregister napi. If arg has been specified copy the busy poll timeout and + * prefer busy poll setting to the passed in structure. + */ +int io_unregister_napi(struct io_ring_ctx *ctx, void __user *arg) +{ + const struct io_uring_napi curr = { + .busy_poll_to = ktime_to_us(ctx->napi_busy_poll_dt), + .prefer_busy_poll = ctx->napi_prefer_busy_poll + }; + + if (arg && copy_to_user(arg, &curr, sizeof(curr))) + return -EFAULT; + + WRITE_ONCE(ctx->napi_track_mode, IO_URING_NAPI_TRACKING_INACTIVE); + WRITE_ONCE(ctx->napi_busy_poll_dt, 0); + WRITE_ONCE(ctx->napi_prefer_busy_poll, false); + io_napi_free(ctx); + return 0; +} + +/* + * __io_napi_busy_loop() - execute busy poll loop + * @ctx: pointer to io-uring context structure + * @iowq: pointer to io wait queue + * + * Execute the busy poll loop and merge the spliced off list. + */ +void __io_napi_busy_loop(struct io_ring_ctx *ctx, struct io_wait_queue *iowq) +{ + if (ctx->flags & IORING_SETUP_SQPOLL) + return; + + iowq->napi_busy_poll_dt = READ_ONCE(ctx->napi_busy_poll_dt); + if (iowq->timeout != KTIME_MAX) { + ktime_t dt = ktime_sub(iowq->timeout, io_get_time(ctx)); + + iowq->napi_busy_poll_dt = min_t(u64, iowq->napi_busy_poll_dt, dt); + } + + iowq->napi_prefer_busy_poll = READ_ONCE(ctx->napi_prefer_busy_poll); + io_napi_blocking_busy_loop(ctx, iowq); +} + +/* + * io_napi_sqpoll_busy_poll() - busy poll loop for sqpoll + * @ctx: pointer to io-uring context structure + * + * Splice of the napi list and execute the napi busy poll loop. + */ +int io_napi_sqpoll_busy_poll(struct io_ring_ctx *ctx) +{ + bool is_stale = false; + + if (!READ_ONCE(ctx->napi_busy_poll_dt)) + return 0; + if (list_empty_careful(&ctx->napi_list)) + return 0; + + scoped_guard(rcu) { + is_stale = __io_napi_do_busy_loop(ctx, NULL, NULL); + } + + io_napi_remove_stale(ctx, is_stale); + return 1; +} + +#endif |
