linux-kernel - [PATCH v4 5/5] drm/qxl: properly free qxl releases

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Message-Id: <20210126165812.1661512-6-kraxel@redhat.com>
Date:   Tue, 26 Jan 2021 17:58:12 +0100
From:   Gerd Hoffmann <kraxel@...hat.com>
To:     dri-devel@...ts.freedesktop.org
Cc:     Gerd Hoffmann <kraxel@...hat.com>,
        Dave Airlie <airlied@...hat.com>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        virtualization@...ts.linux-foundation.org (open list:DRM DRIVER FOR QXL
        VIRTUAL GPU),
        spice-devel@...ts.freedesktop.org (open list:DRM DRIVER FOR QXL VIRTUAL
        GPU), linux-kernel@...r.kernel.org (open list)
Subject: [PATCH v4 5/5] drm/qxl: properly free qxl releases

Signed-off-by: Gerd Hoffmann <kraxel@...hat.com>
---
 drivers/gpu/drm/qxl/qxl_drv.h     |  1 +
 drivers/gpu/drm/qxl/qxl_kms.c     | 22 ++++++++++++++++++++--
 drivers/gpu/drm/qxl/qxl_release.c |  2 ++
 3 files changed, 23 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/qxl/qxl_drv.h b/drivers/gpu/drm/qxl/qxl_drv.h
index 01354b43c413..1c57b587b6a7 100644
--- a/drivers/gpu/drm/qxl/qxl_drv.h
+++ b/drivers/gpu/drm/qxl/qxl_drv.h
@@ -214,6 +214,7 @@ struct qxl_device {
 	spinlock_t	release_lock;
 	struct idr	release_idr;
 	uint32_t	release_seqno;
+	atomic_t	release_count;
 	spinlock_t release_idr_lock;
 	struct mutex	async_io_mutex;
 	unsigned int last_sent_io_cmd;
diff --git a/drivers/gpu/drm/qxl/qxl_kms.c b/drivers/gpu/drm/qxl/qxl_kms.c
index 4a60a52ab62e..f177f72bfc12 100644
--- a/drivers/gpu/drm/qxl/qxl_kms.c
+++ b/drivers/gpu/drm/qxl/qxl_kms.c
@@ -25,6 +25,7 @@
 
 #include <linux/io-mapping.h>
 #include <linux/pci.h>
+#include <linux/delay.h>
 
 #include <drm/drm_drv.h>
 #include <drm/drm_managed.h>
@@ -286,8 +287,25 @@ int qxl_device_init(struct qxl_device *qdev,
 
 void qxl_device_fini(struct qxl_device *qdev)
 {
-	qxl_bo_unref(&qdev->current_release_bo[0]);
-	qxl_bo_unref(&qdev->current_release_bo[1]);
+	int cur_idx, try;
+
+	for (cur_idx = 0; cur_idx < 3; cur_idx++) {
+		if (!qdev->current_release_bo[cur_idx])
+			continue;
+		qxl_bo_unpin(qdev->current_release_bo[cur_idx]);
+		qxl_bo_unref(&qdev->current_release_bo[cur_idx]);
+		qdev->current_release_bo_offset[cur_idx] = 0;
+		qdev->current_release_bo[cur_idx] = NULL;
+	}
+
+	/*
+	 * Ask host to release resources (+fill release ring),
+	 * then wait for the release actually happening.
+	 */
+	qxl_io_notify_oom(qdev);
+	for (try = 0; try < 20 && atomic_read(&qdev->release_count) > 0; try++)
+		msleep(20);
+
 	qxl_gem_fini(qdev);
 	qxl_bo_fini(qdev);
 	flush_work(&qdev->gc_work);
diff --git a/drivers/gpu/drm/qxl/qxl_release.c b/drivers/gpu/drm/qxl/qxl_release.c
index 28013fd1f8ea..43a5436853b7 100644
--- a/drivers/gpu/drm/qxl/qxl_release.c
+++ b/drivers/gpu/drm/qxl/qxl_release.c
@@ -196,6 +196,7 @@ qxl_release_free(struct qxl_device *qdev,
 		qxl_release_free_list(release);
 		kfree(release);
 	}
+	atomic_dec(&qdev->release_count);
 }
 
 static int qxl_release_bo_alloc(struct qxl_device *qdev,
@@ -344,6 +345,7 @@ int qxl_alloc_release_reserved(struct qxl_device *qdev, unsigned long size,
 			*rbo = NULL;
 		return idr_ret;
 	}
+	atomic_inc(&qdev->release_count);
 
 	mutex_lock(&qdev->release_mutex);
 	if (qdev->current_release_bo_offset[cur_idx] + 1 >= releases_per_bo[cur_idx]) {
-- 
2.29.2