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From:   Christian Brauner <brauner@kernel.org>
Date:   Thu, 13 Jul 2023 12:05:38 +0200
Subject: [PATCH 2/2] eventfd: simplify eventfd_signal_mask()
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To:     linux-fsdevel@vger.kernel.org
Cc:     Vitaly Kuznetsov <vkuznets@redhat.com>,
        Sean Christopherson <seanjc@google.com>,
        Paolo Bonzini <pbonzini@redhat.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>, x86@kernel.org,
        David Woodhouse <dwmw2@infradead.org>,
        Paul Durrant <paul@xen.org>, Oded Gabbay <ogabbay@kernel.org>,
        Wu Hao <hao.wu@intel.com>, Tom Rix <trix@redhat.com>,
        Moritz Fischer <mdf@kernel.org>, Xu Yilun <yilun.xu@intel.com>,
        Zhenyu Wang <zhenyuw@linux.intel.com>,
        Zhi Wang <zhi.a.wang@intel.com>,
        Jani Nikula <jani.nikula@linux.intel.com>,
        Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
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        Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        Leon Romanovsky <leon@kernel.org>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Frederic Barrat <fbarrat@linux.ibm.com>,
        Andrew Donnellan <ajd@linux.ibm.com>,
        Arnd Bergmann <arnd@arndb.de>,
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        Halil Pasic <pasic@linux.ibm.com>,
        Vineeth Vijayan <vneethv@linux.ibm.com>,
        Peter Oberparleiter <oberpar@linux.ibm.com>,
        Heiko Carstens <hca@linux.ibm.com>,
        Vasily Gorbik <gor@linux.ibm.com>,
        Alexander Gordeev <agordeev@linux.ibm.com>,
        Christian Borntraeger <borntraeger@linux.ibm.com>,
        Sven Schnelle <svens@linux.ibm.com>,
        Tony Krowiak <akrowiak@linux.ibm.com>,
        Jason Herne <jjherne@linux.ibm.com>,
        Harald Freudenberger <freude@linux.ibm.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Jason Wang <jasowang@redhat.com>,
        Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
        Diana Craciun <diana.craciun@oss.nxp.com>,
        Alex Williamson <alex.williamson@redhat.com>,
        Eric Auger <eric.auger@redhat.com>, Fei Li <fei1.li@intel.com>,
        Benjamin LaHaise <bcrl@kvack.org>,
        Christian Brauner <brauner@kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Shakeel Butt <shakeelb@google.com>,
        Muchun Song <muchun.song@linux.dev>,
        Kirti Wankhede <kwankhede@nvidia.com>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
        linux-fpga@vger.kernel.org, intel-gvt-dev@lists.freedesktop.org,
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        linux-aio@kvack.org, cgroups@vger.kernel.org, linux-mm@kvack.org,
        Jens Axboe <axboe@kernel.dk>,
        Pavel Begunkov <asml.silence@gmail.com>,
        io-uring@vger.kernel.org
Precedence: bulk

The eventfd_signal_mask() helper was introduced for io_uring and similar
to eventfd_signal() it always passed 1 for @n. So don't bother with that
argument at all.

Signed-off-by: Christian Brauner <brauner@kernel.org>
---
 drivers/gpu/drm/i915/gvt/interrupt.c | 2 +-
 fs/eventfd.c                         | 9 +++++----
 include/linux/eventfd.h              | 9 ++++-----
 io_uring/io_uring.c                  | 4 ++--
 4 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gvt/interrupt.c b/drivers/gpu/drm/i915/gvt/interrupt.c
index 3d9e09c2add4..31aff6f733d4 100644
--- a/drivers/gpu/drm/i915/gvt/interrupt.c
+++ b/drivers/gpu/drm/i915/gvt/interrupt.c
@@ -435,7 +435,7 @@ static int inject_virtual_interrupt(struct intel_vgpu *vgpu)
 	 */
 	if (!test_bit(INTEL_VGPU_STATUS_ATTACHED, vgpu->status))
 		return -ESRCH;
-	if (vgpu->msi_trigger && eventfd_signal(vgpu->msi_trigger) != 1)
+	if (vgpu->msi_trigger && !eventfd_signal(vgpu->msi_trigger))
 		return -EFAULT;
 	return 0;
 }
diff --git a/fs/eventfd.c b/fs/eventfd.c
index dc9e01053235..077be5da72bd 100644
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -43,9 +43,10 @@ struct eventfd_ctx {
 	int id;
 };
 
-__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask)
+bool eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask)
 {
 	unsigned long flags;
+	__u64 n = 1;
 
 	/*
 	 * Deadlock or stack overflow issues can happen if we recurse here
@@ -68,7 +69,7 @@ __u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask)
 	current->in_eventfd = 0;
 	spin_unlock_irqrestore(&ctx->wqh.lock, flags);
 
-	return n;
+	return n == 1;
 }
 
 /**
@@ -82,9 +83,9 @@ __u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask)
  *
  * Returns the amount by which the counter was incremented.
  */
-__u64 eventfd_signal(struct eventfd_ctx *ctx)
+bool eventfd_signal(struct eventfd_ctx *ctx)
 {
-	return eventfd_signal_mask(ctx, 1, 0);
+	return eventfd_signal_mask(ctx, 0);
 }
 EXPORT_SYMBOL_GPL(eventfd_signal);
 
diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h
index 562089431551..0155ee25f7c8 100644
--- a/include/linux/eventfd.h
+++ b/include/linux/eventfd.h
@@ -35,8 +35,8 @@ void eventfd_ctx_put(struct eventfd_ctx *ctx);
 struct file *eventfd_fget(int fd);
 struct eventfd_ctx *eventfd_ctx_fdget(int fd);
 struct eventfd_ctx *eventfd_ctx_fileget(struct file *file);
-__u64 eventfd_signal(struct eventfd_ctx *ctx);
-__u64 eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n, __poll_t mask);
+bool eventfd_signal(struct eventfd_ctx *ctx);
+bool eventfd_signal_mask(struct eventfd_ctx *ctx, __poll_t mask);
 int eventfd_ctx_remove_wait_queue(struct eventfd_ctx *ctx, wait_queue_entry_t *wait,
 				  __u64 *cnt);
 void eventfd_ctx_do_read(struct eventfd_ctx *ctx, __u64 *cnt);
@@ -58,13 +58,12 @@ static inline struct eventfd_ctx *eventfd_ctx_fdget(int fd)
 	return ERR_PTR(-ENOSYS);
 }
 
-static inline int eventfd_signal(struct eventfd_ctx *ctx)
+static inline bool eventfd_signal(struct eventfd_ctx *ctx)
 {
 	return -ENOSYS;
 }
 
-static inline int eventfd_signal_mask(struct eventfd_ctx *ctx, __u64 n,
-				      unsigned mask)
+static inline bool eventfd_signal_mask(struct eventfd_ctx *ctx, unsigned mask)
 {
 	return -ENOSYS;
 }
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index e8096d502a7c..a9359ef73935 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -537,7 +537,7 @@ static void io_eventfd_ops(struct rcu_head *rcu)
 	int ops = atomic_xchg(&ev_fd->ops, 0);
 
 	if (ops & BIT(IO_EVENTFD_OP_SIGNAL_BIT))
-		eventfd_signal_mask(ev_fd->cq_ev_fd, 1, EPOLL_URING_WAKE);
+		eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE);
 
 	/* IO_EVENTFD_OP_FREE_BIT may not be set here depending on callback
 	 * ordering in a race but if references are 0 we know we have to free
@@ -573,7 +573,7 @@ static void io_eventfd_signal(struct io_ring_ctx *ctx)
 		goto out;
 
 	if (likely(eventfd_signal_allowed())) {
-		eventfd_signal_mask(ev_fd->cq_ev_fd, 1, EPOLL_URING_WAKE);
+		eventfd_signal_mask(ev_fd->cq_ev_fd, EPOLL_URING_WAKE);
 	} else {
 		atomic_inc(&ev_fd->refs);
 		if (!atomic_fetch_or(BIT(IO_EVENTFD_OP_SIGNAL_BIT), &ev_fd->ops))

-- 
2.34.1