[PATCH v12 28/40] virtio_pci: introduce helper to get/set queue reset

From: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
To: virtualization@lists.linux-foundation.org
Cc: Richard Weinberger <richard@nod.at>,
	Anton Ivanov <anton.ivanov@cambridgegreys.com>,
	Johannes Berg <johannes@sipsolutions.net>,
	"Michael S. Tsirkin" <mst@redhat.com>,
	Jason Wang <jasowang@redhat.com>,
	"David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	Hans de Goede <hdegoede@redhat.com>,
	Mark Gross <markgross@kernel.org>,
	Vadim Pasternak <vadimp@nvidia.com>,
	Bjorn Andersson <bjorn.andersson@linaro.org>,
	Mathieu Poirier <mathieu.poirier@linaro.org>,
	Cornelia Huck <cohuck@redhat.com>,
	Halil Pasic <pasic@linux.ibm.com>,
	Eric Farman <farman@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>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Jesper Dangaard Brouer <hawk@kernel.org>,
	John Fastabend <john.fastabend@gmail.com>,
	Xuan Zhuo <xuanzhuo@linux.alibaba.com>,
	Vincent Whitchurch <vincent.whitchurch@axis.com>,
	linux-um@lists.infradead.org, netdev@vger.kernel.org,
	platform-driver-x86@vger.kernel.org,
	linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org,
	kvm@vger.kernel.org, bpf@vger.kernel.org,
	kangjie.xu@linux.alibaba.com
Subject: [PATCH v12 28/40] virtio_pci: introduce helper to get/set queue reset
Date: Wed, 20 Jul 2022 11:04:24 +0800	[thread overview]
Message-ID: <20220720030436.79520-29-xuanzhuo@linux.alibaba.com> (raw)
In-Reply-To: <20220720030436.79520-1-xuanzhuo@linux.alibaba.com>

Introduce new helpers to implement queue reset and get queue reset
status.

 https://github.com/oasis-tcs/virtio-spec/issues/124
 https://github.com/oasis-tcs/virtio-spec/issues/139

Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 drivers/virtio/virtio_pci_modern_dev.c | 39 ++++++++++++++++++++++++++
 include/linux/virtio_pci_modern.h      |  2 ++
 2 files changed, 41 insertions(+)

diff --git a/drivers/virtio/virtio_pci_modern_dev.c b/drivers/virtio/virtio_pci_modern_dev.c
index fa2a9445bb18..869cb46bef96 100644
--- a/drivers/virtio/virtio_pci_modern_dev.c
+++ b/drivers/virtio/virtio_pci_modern_dev.c
@@ -3,6 +3,7 @@
 #include <linux/virtio_pci_modern.h>
 #include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/delay.h>
 
 /*
  * vp_modern_map_capability - map a part of virtio pci capability
@@ -474,6 +475,44 @@ void vp_modern_set_status(struct virtio_pci_modern_device *mdev,
 }
 EXPORT_SYMBOL_GPL(vp_modern_set_status);
 
+/*
+ * vp_modern_get_queue_reset - get the queue reset status
+ * @mdev: the modern virtio-pci device
+ * @index: queue index
+ */
+int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
+{
+	struct virtio_pci_modern_common_cfg __iomem *cfg;
+
+	cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
+
+	vp_iowrite16(index, &cfg->cfg.queue_select);
+	return vp_ioread16(&cfg->queue_reset);
+}
+EXPORT_SYMBOL_GPL(vp_modern_get_queue_reset);
+
+/*
+ * vp_modern_set_queue_reset - reset the queue
+ * @mdev: the modern virtio-pci device
+ * @index: queue index
+ */
+void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index)
+{
+	struct virtio_pci_modern_common_cfg __iomem *cfg;
+
+	cfg = (struct virtio_pci_modern_common_cfg __iomem *)mdev->common;
+
+	vp_iowrite16(index, &cfg->cfg.queue_select);
+	vp_iowrite16(1, &cfg->queue_reset);
+
+	while (vp_ioread16(&cfg->queue_reset))
+		msleep(1);
+
+	while (vp_ioread16(&cfg->cfg.queue_enable))
+		msleep(1);
+}
+EXPORT_SYMBOL_GPL(vp_modern_set_queue_reset);
+
 /*
  * vp_modern_queue_vector - set the MSIX vector for a specific virtqueue
  * @mdev: the modern virtio-pci device
diff --git a/include/linux/virtio_pci_modern.h b/include/linux/virtio_pci_modern.h
index 05123b9a606f..c4eeb79b0139 100644
--- a/include/linux/virtio_pci_modern.h
+++ b/include/linux/virtio_pci_modern.h
@@ -113,4 +113,6 @@ void __iomem * vp_modern_map_vq_notify(struct virtio_pci_modern_device *mdev,
 				       u16 index, resource_size_t *pa);
 int vp_modern_probe(struct virtio_pci_modern_device *mdev);
 void vp_modern_remove(struct virtio_pci_modern_device *mdev);
+int vp_modern_get_queue_reset(struct virtio_pci_modern_device *mdev, u16 index);
+void vp_modern_set_queue_reset(struct virtio_pci_modern_device *mdev, u16 index);
 #endif
-- 
2.31.0

