88 lines
2.1 KiB
C
88 lines
2.1 KiB
C
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// SPDX-License-Identifier: GPL-2.0
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/*
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* Async I/O region for vfio_ccw
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*
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* Copyright Red Hat, Inc. 2019
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*
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* Author(s): Cornelia Huck <cohuck@redhat.com>
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*/
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#include <linux/vfio.h>
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#include "vfio_ccw_private.h"
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static ssize_t vfio_ccw_async_region_read(struct vfio_ccw_private *private,
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char __user *buf, size_t count,
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loff_t *ppos)
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{
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unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
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loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
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struct ccw_cmd_region *region;
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int ret;
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if (pos + count > sizeof(*region))
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return -EINVAL;
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mutex_lock(&private->io_mutex);
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region = private->region[i].data;
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if (copy_to_user(buf, (void *)region + pos, count))
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ret = -EFAULT;
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else
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ret = count;
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mutex_unlock(&private->io_mutex);
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return ret;
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}
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static ssize_t vfio_ccw_async_region_write(struct vfio_ccw_private *private,
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const char __user *buf, size_t count,
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loff_t *ppos)
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{
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unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;
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loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
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struct ccw_cmd_region *region;
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int ret;
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if (pos + count > sizeof(*region))
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return -EINVAL;
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if (!mutex_trylock(&private->io_mutex))
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return -EAGAIN;
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region = private->region[i].data;
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if (copy_from_user((void *)region + pos, buf, count)) {
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ret = -EFAULT;
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goto out_unlock;
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}
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vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_ASYNC_REQ);
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ret = region->ret_code ? region->ret_code : count;
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out_unlock:
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mutex_unlock(&private->io_mutex);
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return ret;
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}
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static void vfio_ccw_async_region_release(struct vfio_ccw_private *private,
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struct vfio_ccw_region *region)
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{
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}
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static const struct vfio_ccw_regops vfio_ccw_async_region_ops = {
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.read = vfio_ccw_async_region_read,
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.write = vfio_ccw_async_region_write,
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.release = vfio_ccw_async_region_release,
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};
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int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private)
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{
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return vfio_ccw_register_dev_region(private,
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VFIO_REGION_SUBTYPE_CCW_ASYNC_CMD,
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&vfio_ccw_async_region_ops,
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sizeof(struct ccw_cmd_region),
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VFIO_REGION_INFO_FLAG_READ |
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VFIO_REGION_INFO_FLAG_WRITE,
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private->cmd_region);
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}
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