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1// SPDX-License-Identifier: GPL-2.02/*3 * Channel path related status regions for vfio_ccw4 *5 * Copyright IBM Corp. 20206 *7 * Author(s): Farhan Ali <alifm@linux.ibm.com>8 *            Eric Farman <farman@linux.ibm.com>9 */10 11#include <linux/slab.h>12#include <linux/vfio.h>13#include "vfio_ccw_private.h"14 15static ssize_t vfio_ccw_schib_region_read(struct vfio_ccw_private *private,16					  char __user *buf, size_t count,17					  loff_t *ppos)18{19	struct subchannel *sch = to_subchannel(private->vdev.dev->parent);20	unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;21	loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;22	struct ccw_schib_region *region;23	int ret;24 25	if (pos + count > sizeof(*region))26		return -EINVAL;27 28	mutex_lock(&private->io_mutex);29	region = private->region[i].data;30 31	if (cio_update_schib(sch)) {32		ret = -ENODEV;33		goto out;34	}35 36	memcpy(region, &sch->schib, sizeof(*region));37 38	if (copy_to_user(buf, (void *)region + pos, count)) {39		ret = -EFAULT;40		goto out;41	}42 43	ret = count;44 45out:46	mutex_unlock(&private->io_mutex);47	return ret;48}49 50static ssize_t vfio_ccw_schib_region_write(struct vfio_ccw_private *private,51					   const char __user *buf, size_t count,52					   loff_t *ppos)53{54	return -EINVAL;55}56 57 58static void vfio_ccw_schib_region_release(struct vfio_ccw_private *private,59					  struct vfio_ccw_region *region)60{61 62}63 64static const struct vfio_ccw_regops vfio_ccw_schib_region_ops = {65	.read = vfio_ccw_schib_region_read,66	.write = vfio_ccw_schib_region_write,67	.release = vfio_ccw_schib_region_release,68};69 70int vfio_ccw_register_schib_dev_regions(struct vfio_ccw_private *private)71{72	return vfio_ccw_register_dev_region(private,73					    VFIO_REGION_SUBTYPE_CCW_SCHIB,74					    &vfio_ccw_schib_region_ops,75					    sizeof(struct ccw_schib_region),76					    VFIO_REGION_INFO_FLAG_READ,77					    private->schib_region);78}79 80static ssize_t vfio_ccw_crw_region_read(struct vfio_ccw_private *private,81					char __user *buf, size_t count,82					loff_t *ppos)83{84	unsigned int i = VFIO_CCW_OFFSET_TO_INDEX(*ppos) - VFIO_CCW_NUM_REGIONS;85	loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;86	struct ccw_crw_region *region;87	struct vfio_ccw_crw *crw;88	int ret;89 90	if (pos + count > sizeof(*region))91		return -EINVAL;92 93	crw = list_first_entry_or_null(&private->crw,94				       struct vfio_ccw_crw, next);95 96	if (crw)97		list_del(&crw->next);98 99	mutex_lock(&private->io_mutex);100	region = private->region[i].data;101 102	if (crw)103		memcpy(&region->crw, &crw->crw, sizeof(region->crw));104 105	if (copy_to_user(buf, (void *)region + pos, count))106		ret = -EFAULT;107	else108		ret = count;109 110	region->crw = 0;111 112	mutex_unlock(&private->io_mutex);113 114	kfree(crw);115 116	/* Notify the guest if more CRWs are on our queue */117	if (!list_empty(&private->crw) && private->crw_trigger)118		eventfd_signal(private->crw_trigger);119 120	return ret;121}122 123static ssize_t vfio_ccw_crw_region_write(struct vfio_ccw_private *private,124					 const char __user *buf, size_t count,125					 loff_t *ppos)126{127	return -EINVAL;128}129 130static void vfio_ccw_crw_region_release(struct vfio_ccw_private *private,131					struct vfio_ccw_region *region)132{133 134}135 136static const struct vfio_ccw_regops vfio_ccw_crw_region_ops = {137	.read = vfio_ccw_crw_region_read,138	.write = vfio_ccw_crw_region_write,139	.release = vfio_ccw_crw_region_release,140};141 142int vfio_ccw_register_crw_dev_regions(struct vfio_ccw_private *private)143{144	return vfio_ccw_register_dev_region(private,145					    VFIO_REGION_SUBTYPE_CCW_CRW,146					    &vfio_ccw_crw_region_ops,147					    sizeof(struct ccw_crw_region),148					    VFIO_REGION_INFO_FLAG_READ,149					    private->crw_region);150}151