diff options
Diffstat (limited to 'drivers/virtio/virtio_mmio.c')
| -rw-r--r-- | drivers/virtio/virtio_mmio.c | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 627ac0487494..238383ff1064 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -498,6 +498,36 @@ static const char *vm_bus_name(struct virtio_device *vdev) return vm_dev->pdev->name; } +static bool vm_get_shm_region(struct virtio_device *vdev, + struct virtio_shm_region *region, u8 id) +{ + struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev); + u64 len, addr; + + /* Select the region we're interested in */ + writel(id, vm_dev->base + VIRTIO_MMIO_SHM_SEL); + + /* Read the region size */ + len = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_LOW); + len |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_LEN_HIGH) << 32; + + region->len = len; + + /* Check if region length is -1. If that's the case, the shared memory + * region does not exist and there is no need to proceed further. + */ + if (len == ~(u64)0) + return false; + + /* Read the region base address */ + addr = (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_LOW); + addr |= (u64) readl(vm_dev->base + VIRTIO_MMIO_SHM_BASE_HIGH) << 32; + + region->addr = addr; + + return true; +} + static const struct virtio_config_ops virtio_mmio_config_ops = { .get = vm_get, .set = vm_set, @@ -510,6 +540,7 @@ static const struct virtio_config_ops virtio_mmio_config_ops = { .get_features = vm_get_features, .finalize_features = vm_finalize_features, .bus_name = vm_bus_name, + .get_shm_region = vm_get_shm_region, }; |