diff options
| -rw-r--r-- | samples/vfio-mdev/mbochs.c | 24 |
1 files changed, 15 insertions, 9 deletions
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c index e81b875b4d87..3e885be7d076 100644 --- a/samples/vfio-mdev/mbochs.c +++ b/samples/vfio-mdev/mbochs.c @@ -129,7 +129,7 @@ static dev_t mbochs_devt; static struct class *mbochs_class; static struct cdev mbochs_cdev; static struct device mbochs_dev; -static int mbochs_used_mbytes; +static atomic_t mbochs_avail_mbytes; static const struct vfio_device_ops mbochs_dev_ops; struct vfio_region_info_ext { @@ -507,18 +507,22 @@ static int mbochs_reset(struct mdev_state *mdev_state) static int mbochs_probe(struct mdev_device *mdev) { + int avail_mbytes = atomic_read(&mbochs_avail_mbytes); const struct mbochs_type *type = &mbochs_types[mdev_get_type_group_id(mdev)]; struct device *dev = mdev_dev(mdev); struct mdev_state *mdev_state; int ret = -ENOMEM; - if (type->mbytes + mbochs_used_mbytes > max_mbytes) - return -ENOMEM; + do { + if (avail_mbytes < type->mbytes) + return -ENOSPC; + } while (!atomic_try_cmpxchg(&mbochs_avail_mbytes, &avail_mbytes, + avail_mbytes - type->mbytes)); mdev_state = kzalloc(sizeof(struct mdev_state), GFP_KERNEL); if (mdev_state == NULL) - return -ENOMEM; + goto err_avail; vfio_init_group_dev(&mdev_state->vdev, &mdev->dev, &mbochs_dev_ops); mdev_state->vconfig = kzalloc(MBOCHS_CONFIG_SPACE_SIZE, GFP_KERNEL); @@ -549,17 +553,17 @@ static int mbochs_probe(struct mdev_device *mdev) mbochs_create_config_space(mdev_state); mbochs_reset(mdev_state); - mbochs_used_mbytes += type->mbytes; - ret = vfio_register_group_dev(&mdev_state->vdev); if (ret) goto err_mem; dev_set_drvdata(&mdev->dev, mdev_state); return 0; - err_mem: + kfree(mdev_state->pages); kfree(mdev_state->vconfig); kfree(mdev_state); +err_avail: + atomic_add(type->mbytes, &mbochs_avail_mbytes); return ret; } @@ -567,8 +571,8 @@ static void mbochs_remove(struct mdev_device *mdev) { struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev); - mbochs_used_mbytes -= mdev_state->type->mbytes; vfio_unregister_group_dev(&mdev_state->vdev); + atomic_add(mdev_state->type->mbytes, &mbochs_avail_mbytes); kfree(mdev_state->pages); kfree(mdev_state->vconfig); kfree(mdev_state); @@ -1351,7 +1355,7 @@ static ssize_t available_instances_show(struct mdev_type *mtype, { const struct mbochs_type *type = &mbochs_types[mtype_get_type_group_id(mtype)]; - int count = (max_mbytes - mbochs_used_mbytes) / type->mbytes; + int count = atomic_read(&mbochs_avail_mbytes) / type->mbytes; return sprintf(buf, "%d\n", count); } @@ -1433,6 +1437,8 @@ static int __init mbochs_dev_init(void) { int ret = 0; + atomic_set(&mbochs_avail_mbytes, max_mbytes); + ret = alloc_chrdev_region(&mbochs_devt, 0, MINORMASK + 1, MBOCHS_NAME); if (ret < 0) { pr_err("Error: failed to register mbochs_dev, err: %d\n", ret); |