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Diffstat (limited to 'drivers/s390/cio/vfio_ccw_async.c')
-rw-r--r--drivers/s390/cio/vfio_ccw_async.c87
1 files changed, 87 insertions, 0 deletions
diff --git a/drivers/s390/cio/vfio_ccw_async.c b/drivers/s390/cio/vfio_ccw_async.c
new file mode 100644
index 000000000..420d89ba7
--- /dev/null
+++ b/drivers/s390/cio/vfio_ccw_async.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Async I/O region for vfio_ccw
+ *
+ * Copyright Red Hat, Inc. 2019
+ *
+ * Author(s): Cornelia Huck <cohuck@redhat.com>
+ */
+
+#include <linux/vfio.h>
+
+#include "vfio_ccw_private.h"
+
+static ssize_t vfio_ccw_async_region_read(struct vfio_ccw_private *private,
+ char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
+ loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
+ struct ccw_cmd_region *region;
+ int ret;
+
+ if (pos + count > sizeof(*region))
+ return -EINVAL;
+
+ mutex_lock(&private->io_mutex);
+ region = private->region[i].data;
+ if (copy_to_user(buf, (void *)region + pos, count))
+ ret = -EFAULT;
+ else
+ ret = count;
+ mutex_unlock(&private->io_mutex);
+ return ret;
+}
+
+static ssize_t vfio_ccw_async_region_write(struct vfio_ccw_private *private,
+ const char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
+ loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
+ struct ccw_cmd_region *region;
+ int ret;
+
+ if (pos + count > sizeof(*region))
+ return -EINVAL;
+
+ if (!mutex_trylock(&private->io_mutex))
+ return -EAGAIN;
+
+ region = private->region[i].data;
+ if (copy_from_user((void *)region + pos, buf, count)) {
+ ret = -EFAULT;
+ goto out_unlock;
+ }
+
+ vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_ASYNC_REQ);
+
+ ret = region->ret_code ? region->ret_code : count;
+
+out_unlock:
+ mutex_unlock(&private->io_mutex);
+ return ret;
+}
+
+static void vfio_ccw_async_region_release(struct vfio_ccw_private *private,
+ struct vfio_ccw_region *region)
+{
+
+}
+
+static const struct vfio_ccw_regops vfio_ccw_async_region_ops = {
+ .read = vfio_ccw_async_region_read,
+ .write = vfio_ccw_async_region_write,
+ .release = vfio_ccw_async_region_release,
+};
+
+int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private)
+{
+ return vfio_ccw_register_dev_region(private,
+ VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD,
+ &vfio_ccw_async_region_ops,
+ sizeof(struct ccw_cmd_region),
+ VFIO_REGION_INFO_FLAG_READ |
+ VFIO_REGION_INFO_FLAG_WRITE,
+ private->cmd_region);
+}