[PATCH v4 07/14] vfio/platform: Use open_device() instead of open coding a refcnt scheme

Jason Gunthorpe
2021-08-06T01:19:21Z

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>
---
drivers/vfio/platform/vfio_platform_common.c | 95 ++++++++-----------
drivers/vfio/platform/vfio_platform_private.h | 1 -
2 files changed, 40 insertions(+), 56 deletions(-)

diff --git a/drivers/vfio/platform/vfio_platform_common.c b/drivers/vfio/platform/vfio_platform_common.c
index bdde8605178cd2..6af7ce7d619c25 100644
--- 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)
-{
- struct vfio_platform_device *vdev =
- container_of(core_vdev, struct vfio_platform_device, vdev);
-
- 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);
- }
-
- mutex_unlock(&driver_lock);
-}
-
-static int vfio_platform_open(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;
-
- ret = vfio_platform_regions_init(vdev);
- if (ret)
- goto err_reg;
-
- 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 = 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 (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 : "");
}
+ pm_runtime_put(vdev->device);
+ vfio_platform_regions_cleanup(vdev);
+ vfio_platform_irq_cleanup(vdev);
+}

- vdev->refcnt++;
+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_unlock(&driver_lock);
+ ret = vfio_platform_regions_init(vdev);
+ if (ret)
+ return ret;
+
+ 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 = 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;
+ }
return 0;

err_rst:
@@ -284,8 +271,6 @@ static int vfio_platform_open(struct vfio_device *core_vdev)
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 dfb834c1365946..520d2a8e8375b2 100644
--- 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;
--
2.32.0