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author | Farhan Ali <alifm@linux.ibm.com> | 2020-05-05 14:27:41 +0200 |
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committer | Cornelia Huck <cohuck@redhat.com> | 2020-06-02 13:14:08 +0200 |
commit | 24c986748ba670c903a9d6a11ee96de2b3f5f1b8 (patch) | |
tree | 4117927cb0d8a23c596dc72b5e0f22f1213efd46 /drivers/s390/cio/vfio_ccw_chp.c | |
parent | vfio-ccw: Refactor the unregister of the async regions (diff) | |
download | linux-dev-24c986748ba670c903a9d6a11ee96de2b3f5f1b8.tar.xz linux-dev-24c986748ba670c903a9d6a11ee96de2b3f5f1b8.zip |
vfio-ccw: Introduce a new schib region
The schib region can be used by userspace to get the subchannel-
information block (SCHIB) for the passthrough subchannel.
This can be useful to get information such as channel path
information via the SCHIB.PMCW fields.
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200505122745.53208-5-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Diffstat (limited to 'drivers/s390/cio/vfio_ccw_chp.c')
-rw-r--r-- | drivers/s390/cio/vfio_ccw_chp.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/drivers/s390/cio/vfio_ccw_chp.c b/drivers/s390/cio/vfio_ccw_chp.c new file mode 100644 index 000000000000..18f3b3e873a9 --- /dev/null +++ b/drivers/s390/cio/vfio_ccw_chp.c @@ -0,0 +1,76 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Channel path related status regions for vfio_ccw + * + * Copyright IBM Corp. 2020 + * + * Author(s): Farhan Ali <alifm@linux.ibm.com> + * Eric Farman <farman@linux.ibm.com> + */ + +#include <linux/vfio.h> +#include "vfio_ccw_private.h" + +static ssize_t vfio_ccw_schib_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_schib_region *region; + int ret; + + if (pos + count > sizeof(*region)) + return -EINVAL; + + mutex_lock(&private->io_mutex); + region = private->region[i].data; + + if (cio_update_schib(private->sch)) { + ret = -ENODEV; + goto out; + } + + memcpy(region, &private->sch->schib, sizeof(*region)); + + if (copy_to_user(buf, (void *)region + pos, count)) { + ret = -EFAULT; + goto out; + } + + ret = count; + +out: + mutex_unlock(&private->io_mutex); + return ret; +} + +static ssize_t vfio_ccw_schib_region_write(struct vfio_ccw_private *private, + const char __user *buf, size_t count, + loff_t *ppos) +{ + return -EINVAL; +} + + +static void vfio_ccw_schib_region_release(struct vfio_ccw_private *private, + struct vfio_ccw_region *region) +{ + +} + +const struct vfio_ccw_regops vfio_ccw_schib_region_ops = { + .read = vfio_ccw_schib_region_read, + .write = vfio_ccw_schib_region_write, + .release = vfio_ccw_schib_region_release, +}; + +int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private) +{ + return vfio_ccw_register_dev_region(private, + VFIO_REGION_SUBTYPE_CCW_SCHIB, + &vfio_ccw_schib_region_ops, + sizeof(struct ccw_schib_region), + VFIO_REGION_INFO_FLAG_READ, + private->schib_region); +} |