linux/drivers/s390/cio/vfio_ccw_cp.h
Eric Farman 1d897e478d vfio-ccw: Move guest_cp storage into common struct
Rather than allocating/freeing a piece of memory every time
we try to figure out how long a CCW chain is, let's use a piece
of memory allocated for each device.

The io_mutex added with commit 4f76617378 ("vfio-ccw: protect
the I/O region") is held for the duration of the VFIO_CCW_EVENT_IO_REQ
event that accesses/uses this space, so there should be no race
concerns with another CPU attempting an (unexpected) SSCH for the
same device.

Suggested-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20190618202352.39702-2-farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
2019-06-21 14:12:19 +02:00

53 lines
1.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* channel program interfaces
*
* Copyright IBM Corp. 2017
*
* Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
* Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
*/
#ifndef _VFIO_CCW_CP_H_
#define _VFIO_CCW_CP_H_
#include <asm/cio.h>
#include <asm/scsw.h>
#include "orb.h"
/*
* Max length for ccw chain.
* XXX: Limit to 256, need to check more?
*/
#define CCWCHAIN_LEN_MAX 256
/**
* struct channel_program - manage information for channel program
* @ccwchain_list: list head of ccwchains
* @orb: orb for the currently processed ssch request
* @mdev: the mediated device to perform page pinning/unpinning
* @initialized: whether this instance is actually initialized
*
* @ccwchain_list is the head of a ccwchain list, that contents the
* translated result of the guest channel program that pointed out by
* the iova parameter when calling cp_init.
*/
struct channel_program {
struct list_head ccwchain_list;
union orb orb;
struct device *mdev;
bool initialized;
struct ccw1 *guest_cp;
};
extern int cp_init(struct channel_program *cp, struct device *mdev,
union orb *orb);
extern void cp_free(struct channel_program *cp);
extern int cp_prefetch(struct channel_program *cp);
extern union orb *cp_get_orb(struct channel_program *cp, u32 intparm, u8 lpm);
extern void cp_update_scsw(struct channel_program *cp, union scsw *scsw);
extern bool cp_iova_pinned(struct channel_program *cp, u64 iova);
#endif