vfio/platform: Use open_device() instead of open coding a refcnt scheme

Platform simply wants to run some code when the device is first
opened/last closed. Use the core framework and locking for this.  Aside
from removing a bit of code this narrows the locking scope from a global
lock.

Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yishai Hadas <yishaih@nvidia.com>
Link: https://lore.kernel.org/r/7-v4-9ea22c5e6afb+1adf-vfio_reflck_jgg@nvidia.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index bdde860..6af7ce7 100644 (file)
--- a/drivers/vfio/platform/vfio_platform_common.c
+++ b/drivers/vfio/platform/vfio_platform_common.c
@@ -218,65 +218,52 @@ static int vfio_platform_call_reset(struct vfio_platform_device *vdev,
        return -EINVAL;
 }
 
-static void vfio_platform_release(struct vfio_device *core_vdev)
+static void vfio_platform_close_device(struct vfio_device *core_vdev)
 {
        struct vfio_platform_device *vdev =
                container_of(core_vdev, struct vfio_platform_device, vdev);
+       const char *extra_dbg = NULL;
+       int ret;
 
-       mutex_lock(&driver_lock);
-
-       if (!(--vdev->refcnt)) {
-               const char *extra_dbg = NULL;
-               int ret;
-
-               ret = vfio_platform_call_reset(vdev, &extra_dbg);
-               if (ret && vdev->reset_required) {
-                       dev_warn(vdev->device, "reset driver is required and reset call failed in release (%d) %s\n",
-                                ret, extra_dbg ? extra_dbg : "");
-                       WARN_ON(1);
-               }
-               pm_runtime_put(vdev->device);
-               vfio_platform_regions_cleanup(vdev);
-               vfio_platform_irq_cleanup(vdev);
+       ret = vfio_platform_call_reset(vdev, &extra_dbg);
+       if (WARN_ON(ret && vdev->reset_required)) {
+               dev_warn(
+                       vdev->device,
+                       "reset driver is required and reset call failed in release (%d) %s\n",
+                       ret, extra_dbg ? extra_dbg : "");
        }
-
-       mutex_unlock(&driver_lock);
+       pm_runtime_put(vdev->device);
+       vfio_platform_regions_cleanup(vdev);
+       vfio_platform_irq_cleanup(vdev);
 }
 
-static int vfio_platform_open(struct vfio_device *core_vdev)
+static int vfio_platform_open_device(struct vfio_device *core_vdev)
 {
        struct vfio_platform_device *vdev =
                container_of(core_vdev, struct vfio_platform_device, vdev);
+       const char *extra_dbg = NULL;
        int ret;
 
-       mutex_lock(&driver_lock);
-
-       if (!vdev->refcnt) {
-               const char *extra_dbg = NULL;
-
-               ret = vfio_platform_regions_init(vdev);
-               if (ret)
-                       goto err_reg;
+       ret = vfio_platform_regions_init(vdev);
+       if (ret)
+               return ret;
 
-               ret = vfio_platform_irq_init(vdev);
-               if (ret)
-                       goto err_irq;
+       ret = vfio_platform_irq_init(vdev);
+       if (ret)
+               goto err_irq;
 
-               ret = pm_runtime_get_sync(vdev->device);
-               if (ret < 0)
-                       goto err_rst;
+       ret = pm_runtime_get_sync(vdev->device);
+       if (ret < 0)
+               goto err_rst;
 
-               ret = vfio_platform_call_reset(vdev, &extra_dbg);
-               if (ret && vdev->reset_required) {
-                       dev_warn(vdev->device, "reset driver is required and reset call failed in open (%d) %s\n",
-                                ret, extra_dbg ? extra_dbg : "");
-                       goto err_rst;
-               }
+       ret = vfio_platform_call_reset(vdev, &extra_dbg);
+       if (ret && vdev->reset_required) {
+               dev_warn(
+                       vdev->device,
+                       "reset driver is required and reset call failed in open (%d) %s\n",
+                       ret, extra_dbg ? extra_dbg : "");
+               goto err_rst;
        }
-
-       vdev->refcnt++;
-
-       mutex_unlock(&driver_lock);
        return 0;
 
 err_rst:
@@ -284,8 +271,6 @@ err_rst:
        vfio_platform_irq_cleanup(vdev);
 err_irq:
        vfio_platform_regions_cleanup(vdev);
-err_reg:
-       mutex_unlock(&driver_lock);
        return ret;
 }
 
@@ -616,8 +601,8 @@ static int vfio_platform_mmap(struct vfio_device *core_vdev, struct vm_area_stru
 
 static const struct vfio_device_ops vfio_platform_ops = {
        .name           = "vfio-platform",
-       .open           = vfio_platform_open,
-       .release        = vfio_platform_release,
+       .open_device    = vfio_platform_open_device,
+       .close_device   = vfio_platform_close_device,
        .ioctl          = vfio_platform_ioctl,
        .read           = vfio_platform_read,
        .write          = vfio_platform_write,

diff --git a/drivers/vfio/platform/vfio_platform_private.h b/drivers/vfio/platform/vfio_platform_private.h
index dfb834c..520d2a8 100644 (file)
--- a/drivers/vfio/platform/vfio_platform_private.h
+++ b/drivers/vfio/platform/vfio_platform_private.h
@@ -48,7 +48,6 @@ struct vfio_platform_device {
        u32                             num_regions;
        struct vfio_platform_irq        *irqs;
        u32                             num_irqs;
-       int                             refcnt;
        struct mutex                    igate;
        const char                      *compat;
        const char                      *acpihid;