linux/drivers/s390/cio/vfio_ccw_private.h
Cornelia Huck d5afd5d135 vfio-ccw: add handling for async channel instructions
Add a region to the vfio-ccw device that can be used to submit
asynchronous I/O instructions. ssch continues to be handled by the
existing I/O region; the new region handles hsch and csch.

Interrupt status continues to be reported through the same channels
as for ssch.

Acked-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-04-24 14:18:51 +02:00

143 lines
3.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Private stuff for vfio_ccw driver
*
* Copyright IBM Corp. 2017
* Copyright Red Hat, Inc. 2019
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
* Cornelia Huck <cohuck@redhat.com>
*/
#ifndef _VFIO_CCW_PRIVATE_H_
#define _VFIO_CCW_PRIVATE_H_
#include <linux/completion.h>
#include <linux/eventfd.h>
#include <linux/workqueue.h>
#include <linux/vfio_ccw.h>
#include "css.h"
#include "vfio_ccw_cp.h"
#define VFIO_CCW_OFFSET_SHIFT 10
#define VFIO_CCW_OFFSET_TO_INDEX(off) (off >> VFIO_CCW_OFFSET_SHIFT)
#define VFIO_CCW_INDEX_TO_OFFSET(index) ((u64)(index) << VFIO_CCW_OFFSET_SHIFT)
#define VFIO_CCW_OFFSET_MASK (((u64)(1) << VFIO_CCW_OFFSET_SHIFT) - 1)
/* capability chain handling similar to vfio-pci */
struct vfio_ccw_private;
struct vfio_ccw_region;
struct vfio_ccw_regops {
ssize_t (*read)(struct vfio_ccw_private *private, char __user *buf,
size_t count, loff_t *ppos);
ssize_t (*write)(struct vfio_ccw_private *private,
const char __user *buf, size_t count, loff_t *ppos);
void (*release)(struct vfio_ccw_private *private,
struct vfio_ccw_region *region);
};
struct vfio_ccw_region {
u32 type;
u32 subtype;
const struct vfio_ccw_regops *ops;
void *data;
size_t size;
u32 flags;
};
int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
unsigned int subtype,
const struct vfio_ccw_regops *ops,
size_t size, u32 flags, void *data);
int vfio_ccw_register_async_dev_regions(struct vfio_ccw_private *private);
/**
* struct vfio_ccw_private
* @sch: pointer to the subchannel
* @state: internal state of the device
* @completion: synchronization helper of the I/O completion
* @avail: available for creating a mediated device
* @mdev: pointer to the mediated device
* @nb: notifier for vfio events
* @io_region: MMIO region to input/output I/O arguments/results
* @io_mutex: protect against concurrent update of I/O regions
* @region: additional regions for other subchannel operations
* @cmd_region: MMIO region for asynchronous I/O commands other than START
* @num_regions: number of additional regions
* @cp: channel program for the current I/O operation
* @irb: irb info received from interrupt
* @scsw: scsw info
* @io_trigger: eventfd ctx for signaling userspace I/O results
* @io_work: work for deferral process of I/O handling
*/
struct vfio_ccw_private {
struct subchannel *sch;
int state;
struct completion *completion;
atomic_t avail;
struct mdev_device *mdev;
struct notifier_block nb;
struct ccw_io_region *io_region;
struct mutex io_mutex;
struct vfio_ccw_region *region;
struct ccw_cmd_region *cmd_region;
int num_regions;
struct channel_program cp;
struct irb irb;
union scsw scsw;
struct eventfd_ctx *io_trigger;
struct work_struct io_work;
} __aligned(8);
extern int vfio_ccw_mdev_reg(struct subchannel *sch);
extern void vfio_ccw_mdev_unreg(struct subchannel *sch);
extern int vfio_ccw_sch_quiesce(struct subchannel *sch);
/*
* States of the device statemachine.
*/
enum vfio_ccw_state {
VFIO_CCW_STATE_NOT_OPER,
VFIO_CCW_STATE_STANDBY,
VFIO_CCW_STATE_IDLE,
VFIO_CCW_STATE_CP_PROCESSING,
VFIO_CCW_STATE_CP_PENDING,
/* last element! */
NR_VFIO_CCW_STATES
};
/*
* Asynchronous events of the device statemachine.
*/
enum vfio_ccw_event {
VFIO_CCW_EVENT_NOT_OPER,
VFIO_CCW_EVENT_IO_REQ,
VFIO_CCW_EVENT_INTERRUPT,
VFIO_CCW_EVENT_ASYNC_REQ,
/* last element! */
NR_VFIO_CCW_EVENTS
};
/*
* Action called through jumptable.
*/
typedef void (fsm_func_t)(struct vfio_ccw_private *, enum vfio_ccw_event);
extern fsm_func_t *vfio_ccw_jumptable[NR_VFIO_CCW_STATES][NR_VFIO_CCW_EVENTS];
static inline void vfio_ccw_fsm_event(struct vfio_ccw_private *private,
int event)
{
vfio_ccw_jumptable[private->state][event](private, event);
}
extern struct workqueue_struct *vfio_ccw_work_q;
#endif