[Intel-gfx] [PATCH 08/10] vfio/mtty: Convert to use vfio_register_group_dev()

Christoph Hellwig
2021-06-15T13:42:52Z

From: Jason Gunthorpe <jgg@nvidia.com>

This is straightforward conversion, the mdev_state is actually serving as
the vfio_device and we can replace all the mdev_get_drvdata()'s and the
wonky dead code with a simple container_of()

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
samples/vfio-mdev/mtty.c | 185 ++++++++++++++++++---------------------
1 file changed, 83 insertions(+), 102 deletions(-)

diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index b9b24be4abda..d2a168420b77 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -127,6 +127,7 @@ struct serial_port {

/* State of each mdev device */
struct mdev_state {
+ struct vfio_device vdev;
int irq_fd;
struct eventfd_ctx *intx_evtfd;
struct eventfd_ctx *msi_evtfd;
@@ -150,6 +151,8 @@ static const struct file_operations vd_fops = {
.owner = THIS_MODULE,
};

+static const struct vfio_device_ops mtty_dev_ops;
+
/* function prototypes */

static int mtty_trigger_interrupt(struct mdev_state *mdev_state);
@@ -631,22 +634,15 @@ static void mdev_read_base(struct mdev_state *mdev_state)
}
}

-static ssize_t mdev_access(struct mdev_device *mdev, u8 *buf, size_t count,
+static ssize_t mdev_access(struct mdev_state *mdev_state, u8 *buf, size_t count,
loff_t pos, bool is_write)
{
- struct mdev_state *mdev_state;
unsigned int index;
loff_t offset;
int ret = 0;

- if (!mdev || !buf)
- return -EINVAL;
-
- mdev_state = mdev_get_drvdata(mdev);
- if (!mdev_state) {
- pr_err("%s mdev_state not found\n", __func__);
+ if (!buf)
return -EINVAL;
- }

mutex_lock(&mdev_state->ops_lock);

@@ -708,15 +704,18 @@ static ssize_t mdev_access(struct mdev_device *mdev, u8 *buf, size_t count,
return ret;
}

-static int mtty_create(struct mdev_device *mdev)
+static int mtty_probe(struct mdev_device *mdev)
{
struct mdev_state *mdev_state;
int nr_ports = mdev_get_type_group_id(mdev) + 1;
+ int ret;

mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL);
if (mdev_state == NULL)
return -ENOMEM;

+ vfio_init_group_dev(&mdev_state->vdev, &mdev->dev, &mtty_dev_ops);
+
mdev_state->nr_ports = nr_ports;
mdev_state->irq_index = -1;
mdev_state->s[0].max_fifo_size = MAX_FIFO_SIZE;
@@ -731,7 +730,6 @@ static int mtty_create(struct mdev_device *mdev)

mutex_init(&mdev_state->ops_lock);
mdev_state->mdev = mdev;
- mdev_set_drvdata(mdev, mdev_state);

mtty_create_config_space(mdev_state);

@@ -739,50 +737,40 @@ static int mtty_create(struct mdev_device *mdev)
list_add(&mdev_state->next, &mdev_devices_list);
mutex_unlock(&mdev_list_lock);

+ ret = vfio_register_group_dev(&mdev_state->vdev);
+ if (ret) {
+ kfree(mdev_state);
+ return ret;
+ }
+ dev_set_drvdata(&mdev->dev, mdev_state);
return 0;
}

-static int mtty_remove(struct mdev_device *mdev)
+static void mtty_remove(struct mdev_device *mdev)
{
- struct mdev_state *mds, *tmp_mds;
- struct mdev_state *mdev_state = mdev_get_drvdata(mdev);
- int ret = -EINVAL;
+ struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev);

+ vfio_unregister_group_dev(&mdev_state->vdev);
mutex_lock(&mdev_list_lock);
- list_for_each_entry_safe(mds, tmp_mds, &mdev_devices_list, next) {
- if (mdev_state == mds) {
- list_del(&mdev_state->next);
- mdev_set_drvdata(mdev, NULL);
- kfree(mdev_state->vconfig);
- kfree(mdev_state);
- ret = 0;
- break;
- }
- }
+ list_del(&mdev_state->next);
mutex_unlock(&mdev_list_lock);

- return ret;
+ kfree(mdev_state->vconfig);
+ kfree(mdev_state);
}

-static int mtty_reset(struct mdev_device *mdev)
+static int mtty_reset(struct mdev_state *mdev_stte)
{
- struct mdev_state *mdev_state;
-
- if (!mdev)
- return -EINVAL;
-
- mdev_state = mdev_get_drvdata(mdev);
- if (!mdev_state)
- return -EINVAL;
-
pr_info("%s: called\n", __func__);

return 0;
}

-static ssize_t mtty_read(struct mdev_device *mdev, char __user *buf,
+static ssize_t mtty_read(struct vfio_device *vdev, char __user *buf,
size_t count, loff_t *ppos)
{
+ struct mdev_state *mdev_state =
+ container_of(vdev, struct mdev_state, vdev);
unsigned int done = 0;
int ret;

@@ -792,7 +780,7 @@ static ssize_t mtty_read(struct mdev_device *mdev, char __user *buf,
if (count >= 4 && !(*ppos % 4)) {
u32 val;

- ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
+ ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
*ppos, false);
if (ret <= 0)
goto read_err;
@@ -804,7 +792,7 @@ static ssize_t mtty_read(struct mdev_device *mdev, char __user *buf,
} else if (count >= 2 && !(*ppos % 2)) {
u16 val;

- ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
+ ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
*ppos, false);
if (ret <= 0)
goto read_err;
@@ -816,7 +804,7 @@ static ssize_t mtty_read(struct mdev_device *mdev, char __user *buf,
} else {
u8 val;

- ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
+ ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
*ppos, false);
if (ret <= 0)
goto read_err;
@@ -839,9 +827,11 @@ static ssize_t mtty_read(struct mdev_device *mdev, char __user *buf,
return -EFAULT;
}

-static ssize_t mtty_write(struct mdev_device *mdev, const char __user *buf,
+static ssize_t mtty_write(struct vfio_device *vdev, const char __user *buf,
size_t count, loff_t *ppos)
{
+ struct mdev_state *mdev_state =
+ container_of(vdev, struct mdev_state, vdev);
unsigned int done = 0;
int ret;

@@ -854,7 +844,7 @@ static ssize_t mtty_write(struct mdev_device *mdev, const char __user *buf,
if (copy_from_user(&val, buf, sizeof(val)))
goto write_err;

- ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
+ ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
*ppos, true);
if (ret <= 0)
goto write_err;
@@ -866,7 +856,7 @@ static ssize_t mtty_write(struct mdev_device *mdev, const char __user *buf,
if (copy_from_user(&val, buf, sizeof(val)))
goto write_err;

- ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
+ ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
*ppos, true);
if (ret <= 0)
goto write_err;
@@ -878,7 +868,7 @@ static ssize_t mtty_write(struct mdev_device *mdev, const char __user *buf,
if (copy_from_user(&val, buf, sizeof(val)))
goto write_err;

- ret = mdev_access(mdev, (u8 *)&val, sizeof(val),
+ ret = mdev_access(mdev_state, (u8 *)&val, sizeof(val),
*ppos, true);
if (ret <= 0)
goto write_err;
@@ -896,19 +886,11 @@ static ssize_t mtty_write(struct mdev_device *mdev, const char __user *buf,
return -EFAULT;
}

-static int mtty_set_irqs(struct mdev_device *mdev, uint32_t flags,
+static int mtty_set_irqs(struct mdev_state *mdev_state, uint32_t flags,
unsigned int index, unsigned int start,
unsigned int count, void *data)
{
int ret = 0;
- struct mdev_state *mdev_state;
-
- if (!mdev)
- return -EINVAL;
-
- mdev_state = mdev_get_drvdata(mdev);
- if (!mdev_state)
- return -EINVAL;

mutex_lock(&mdev_state->ops_lock);
switch (index) {
@@ -1024,21 +1006,13 @@ static int mtty_trigger_interrupt(struct mdev_state *mdev_state)
return ret;
}

-static int mtty_get_region_info(struct mdev_device *mdev,
+static int mtty_get_region_info(struct mdev_state *mdev_state,
struct vfio_region_info *region_info,
u16 *cap_type_id, void **cap_type)
{
unsigned int size = 0;
- struct mdev_state *mdev_state;
u32 bar_index;

- if (!mdev)
- return -EINVAL;
-
- mdev_state = mdev_get_drvdata(mdev);
- if (!mdev_state)
- return -EINVAL;
-
bar_index = region_info->index;
if (bar_index >= VFIO_PCI_NUM_REGIONS)
return -EINVAL;
@@ -1073,8 +1047,7 @@ static int mtty_get_region_info(struct mdev_device *mdev,
return 0;
}

-static int mtty_get_irq_info(struct mdev_device *mdev,
- struct vfio_irq_info *irq_info)
+static int mtty_get_irq_info(struct vfio_irq_info *irq_info)
{
switch (irq_info->index) {
case VFIO_PCI_INTX_IRQ_INDEX:
@@ -1098,8 +1071,7 @@ static int mtty_get_irq_info(struct mdev_device *mdev,
return 0;
}

-static int mtty_get_device_info(struct mdev_device *mdev,
- struct vfio_device_info *dev_info)
+static int mtty_get_device_info(struct vfio_device_info *dev_info)
{
dev_info->flags = VFIO_DEVICE_FLAGS_PCI;
dev_info->num_regions = VFIO_PCI_NUM_REGIONS;
@@ -1108,19 +1080,13 @@ static int mtty_get_device_info(struct mdev_device *mdev,
return 0;
}

-static long mtty_ioctl(struct mdev_device *mdev, unsigned int cmd,
+static long mtty_ioctl(struct vfio_device *vdev, unsigned int cmd,
unsigned long arg)
{
+ struct mdev_state *mdev_state =
+ container_of(vdev, struct mdev_state, vdev);
int ret = 0;
unsigned long minsz;
- struct mdev_state *mdev_state;
-
- if (!mdev)
- return -EINVAL;
-
- mdev_state = mdev_get_drvdata(mdev);
- if (!mdev_state)
- return -ENODEV;

switch (cmd) {
case VFIO_DEVICE_GET_INFO:
@@ -1135,7 +1101,7 @@ static long mtty_ioctl(struct mdev_device *mdev, unsigned int cmd,
if (info.argsz < minsz)
return -EINVAL;

- ret = mtty_get_device_info(mdev, &info);
+ ret = mtty_get_device_info(&info);
if (ret)
return ret;

@@ -1160,7 +1126,7 @@ static long mtty_ioctl(struct mdev_device *mdev, unsigned int cmd,
if (info.argsz < minsz)
return -EINVAL;

- ret = mtty_get_region_info(mdev, &info, &cap_type_id,
+ ret = mtty_get_region_info(mdev_state, &info, &cap_type_id,
&cap_type);
if (ret)
return ret;
@@ -1184,7 +1150,7 @@ static long mtty_ioctl(struct mdev_device *mdev, unsigned int cmd,
(info.index >= mdev_state->dev_info.num_irqs))
return -EINVAL;

- ret = mtty_get_irq_info(mdev, &info);
+ ret = mtty_get_irq_info(&info);
if (ret)
return ret;

@@ -1218,25 +1184,25 @@ static long mtty_ioctl(struct mdev_device *mdev, unsigned int cmd,
return PTR_ERR(data);
}

- ret = mtty_set_irqs(mdev, hdr.flags, hdr.index, hdr.start,
+ ret = mtty_set_irqs(mdev_state, hdr.flags, hdr.index, hdr.start,
hdr.count, data);

kfree(ptr);
return ret;
}
case VFIO_DEVICE_RESET:
- return mtty_reset(mdev);
+ return mtty_reset(mdev_state);
}
return -ENOTTY;
}

-static int mtty_open(struct mdev_device *mdev)
+static int mtty_open(struct vfio_device *vdev)
{
pr_info("%s\n", __func__);
return 0;
}

-static void mtty_close(struct mdev_device *mdev)
+static void mtty_close(struct vfio_device *mdev)
{
pr_info("%s\n", __func__);
}
@@ -1351,18 +1317,31 @@ static struct attribute_group *mdev_type_groups[] = {
NULL,
};

+static const struct vfio_device_ops mtty_dev_ops = {
+ .name = "vfio-mdev",
+ .open = mtty_open,
+ .release = mtty_close,
+ .read = mtty_read,
+ .write = mtty_write,
+ .ioctl = mtty_ioctl,
+};
+
+static struct mdev_driver mtty_driver = {
+ .driver = {
+ .name = "mtty",
+ .owner = THIS_MODULE,
+ .mod_name = KBUILD_MODNAME,
+ .dev_groups = mdev_dev_groups,
+ },
+ .probe = mtty_probe,
+ .remove = mtty_remove,
+};
+
static const struct mdev_parent_ops mdev_fops = {
.owner = THIS_MODULE,
+ .device_driver = &mtty_driver,
.dev_attr_groups = mtty_dev_groups,
- .mdev_attr_groups = mdev_dev_groups,
.supported_type_groups = mdev_type_groups,
- .create = mtty_create,
- .remove = mtty_remove,
- .open = mtty_open,
- .release = mtty_close,
- .read = mtty_read,
- .write = mtty_write,
- .ioctl = mtty_ioctl,
};

static void mtty_device_release(struct device *dev)
@@ -1393,12 +1372,16 @@ static int __init mtty_dev_init(void)

pr_info("major_number:%d\n", MAJOR(mtty_dev.vd_devt));

+ ret = mdev_register_driver(&mtty_driver);
+ if (ret)
+ goto err_cdev;
+
mtty_dev.vd_class = class_create(THIS_MODULE, MTTY_CLASS_NAME);

if (IS_ERR(mtty_dev.vd_class)) {
pr_err("Error: failed to register mtty_dev class\n");
ret = PTR_ERR(mtty_dev.vd_class);
- goto failed1;
+ goto err_driver;
}

mtty_dev.dev.class = mtty_dev.vd_class;
@@ -1407,28 +1390,25 @@ static int __init mtty_dev_init(void)

ret = device_register(&mtty_dev.dev);
if (ret)
- goto failed2;
+ goto err_class;

ret = mdev_register_device(&mtty_dev.dev, &mdev_fops);
if (ret)
- goto failed3;
+ goto err_device;

mutex_init(&mdev_list_lock);
INIT_LIST_HEAD(&mdev_devices_list);
+ return 0;

- goto all_done;
-
-failed3:
-
+err_device:
device_unregister(&mtty_dev.dev);
-failed2:
+err_class:
class_destroy(mtty_dev.vd_class);
-
-failed1:
+err_driver:
+ mdev_unregister_driver(&mtty_driver);
+err_cdev:
cdev_del(&mtty_dev.vd_cdev);
unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
-
-all_done:
return ret;
}

@@ -1439,6 +1419,7 @@ static void __exit mtty_dev_exit(void)

device_unregister(&mtty_dev.dev);
idr_destroy(&mtty_dev.vd_idr);
+ mdev_unregister_driver(&mtty_driver);
cdev_del(&mtty_dev.vd_cdev);
unregister_chrdev_region(mtty_dev.vd_devt, MINORMASK + 1);
class_destroy(mtty_dev.vd_class);
--
2.30.2