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
  ...

1 files changed, 173 insertions, 0 deletions

diff --git a/io_uring/eventfd.c b/io_uring/eventfd.c
new file mode 100644
index 000000000..d656cc2a0
--- /dev/null
+++ b/io_uring/eventfd.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/eventfd.h>
+#include <linux/eventpoll.h>
+#include <linux/io_uring.h>
+#include <linux/io_uring_types.h>
+
+#include "io-wq.h"
+#include "eventfd.h"
+
+struct io_ev_fd {
+	struct eventfd_ctx	*cq_ev_fd;
+	unsigned int		eventfd_async;
+	/* protected by ->completion_lock */
+	unsigned		last_cq_tail;
+	refcount_t		refs;
+	atomic_t		ops;
+	struct rcu_head		rcu;
+};
+
+enum {
+	IO_EVENTFD_OP_SIGNAL_BIT,
+};
+
+static void io_eventfd_free(struct rcu_head *rcu)
+{
+	struct io_ev_fd *ev_fd = container_of(rcu, struct io_ev_fd, rcu);
+
+	eventfd_ctx_put(ev_fd->cq_ev_fd);
+	kfree(ev_fd);
+}
+
+static void io_eventfd_put(struct io_ev_fd *ev_fd)
+{
+	if (refcount_dec_and_test(&ev_fd->refs))
+		call_rcu(&ev_fd->rcu, io_eventfd_free);
+}
+
+static void io_eventfd_do_signal(struct rcu_head *rcu)
+{
+	struct io_ev_fd *ev_fd = container_of(rcu, struct io_ev_fd, rcu);
+
+	atomic_andnot(BIT(IO_EVENTFD_OP_SIGNAL_BIT), &ev_fd->ops);
+	eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE);
+	io_eventfd_put(ev_fd);
+}
+
+/*
+ * Returns true if the caller should put the ev_fd reference, false if not.
+ */
+static bool __io_eventfd_signal(struct io_ev_fd *ev_fd)
+{
+	if (eventfd_signal_allowed()) {
+		eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE);
+		return true;
+	}
+	if (!atomic_fetch_or(BIT(IO_EVENTFD_OP_SIGNAL_BIT), &ev_fd->ops)) {
+		call_rcu_hurry(&ev_fd->rcu, io_eventfd_do_signal);
+		return false;
+	}
+	return true;
+}
+
+/*
+ * Trigger if eventfd_async isn't set, or if it's set and the caller is
+ * an async worker.
+ */
+static bool io_eventfd_trigger(struct io_ev_fd *ev_fd)
+{
+	return !ev_fd->eventfd_async || io_wq_current_is_worker();
+}
+
+void io_eventfd_signal(struct io_ring_ctx *ctx, bool cqe_event)
+{
+	bool skip = false;
+	struct io_ev_fd *ev_fd;
+	struct io_rings *rings;
+
+	guard(rcu)();
+
+	rings = rcu_dereference(ctx->rings_rcu);
+	if (!rings)
+		return;
+	if (READ_ONCE(rings->cq_flags) & IORING_CQ_EVENTFD_DISABLED)
+		return;
+	ev_fd = rcu_dereference(ctx->io_ev_fd);
+	/*
+	 * Check again if ev_fd exists in case an io_eventfd_unregister call
+	 * completed between the NULL check of ctx->io_ev_fd at the start of
+	 * the function and rcu_read_lock.
+	 */
+	if (!ev_fd)
+		return;
+	if (!io_eventfd_trigger(ev_fd) || !refcount_inc_not_zero(&ev_fd->refs))
+		return;
+
+	if (cqe_event) {
+		/*
+		 * Eventfd should only get triggered when at least one event
+		 * has been posted. Some applications rely on the eventfd
+		 * notification count only changing IFF a new CQE has been
+		 * added to the CQ ring. There's no dependency on 1:1
+		 * relationship between how many times this function is called
+		 * (and hence the eventfd count) and number of CQEs posted to
+		 * the CQ ring.
+		 */
+		spin_lock(&ctx->completion_lock);
+		skip = ctx->cached_cq_tail == ev_fd->last_cq_tail;
+		ev_fd->last_cq_tail = ctx->cached_cq_tail;
+		spin_unlock(&ctx->completion_lock);
+	}
+
+	if (skip || __io_eventfd_signal(ev_fd))
+		io_eventfd_put(ev_fd);
+}
+
+int io_eventfd_register(struct io_ring_ctx *ctx, void __user *arg,
+			unsigned int eventfd_async)
+{
+	struct io_ev_fd *ev_fd;
+	__s32 __user *fds = arg;
+	int fd;
+
+	ev_fd = rcu_dereference_protected(ctx->io_ev_fd,
+					lockdep_is_held(&ctx->uring_lock));
+	if (ev_fd)
+		return -EBUSY;
+
+	if (copy_from_user(&fd, fds, sizeof(*fds)))
+		return -EFAULT;
+
+	ev_fd = kmalloc_obj(*ev_fd);
+	if (!ev_fd)
+		return -ENOMEM;
+
+	ev_fd->cq_ev_fd = eventfd_ctx_fdget(fd);
+	if (IS_ERR(ev_fd->cq_ev_fd)) {
+		int ret = PTR_ERR(ev_fd->cq_ev_fd);
+
+		kfree(ev_fd);
+		return ret;
+	}
+
+	spin_lock(&ctx->completion_lock);
+	ev_fd->last_cq_tail = ctx->cached_cq_tail;
+	spin_unlock(&ctx->completion_lock);
+
+	ev_fd->eventfd_async = eventfd_async;
+	ctx->int_flags |= IO_RING_F_HAS_EVFD;
+	refcount_set(&ev_fd->refs, 1);
+	atomic_set(&ev_fd->ops, 0);
+	rcu_assign_pointer(ctx->io_ev_fd, ev_fd);
+	return 0;
+}
+
+int io_eventfd_unregister(struct io_ring_ctx *ctx)
+{
+	struct io_ev_fd *ev_fd;
+
+	ev_fd = rcu_dereference_protected(ctx->io_ev_fd,
+					lockdep_is_held(&ctx->uring_lock));
+	if (ev_fd) {
+		ctx->int_flags &= ~IO_RING_F_HAS_EVFD;
+		rcu_assign_pointer(ctx->io_ev_fd, NULL);
+		io_eventfd_put(ev_fd);
+		return 0;
+	}
+
+	return -ENXIO;
+}