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/*
* Copyright (c) 2007 Paulo R. Zanoni, Tiago Vignatti
* 2009 Tiago Vignatti
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include "pciaccess.h"
/* ALL messages *should* fit in this buffer */
#define BUFSIZE 128
#define VGAARB_DEV "/dev/vga_arbiter"
int
pci_device_vgaarb_init(struct pci_device *dev)
{
dev->vgaarb_rsrc = VGA_ARB_RSRC_NONE;
if ((dev->vgaarb_fd = open (VGAARB_DEV, O_RDWR)) < 0) {
perror("device open failed");
return 1;
}
return 0;
}
void
pci_device_vgaarb_fini(struct pci_device *dev)
{
if (close(dev->vgaarb_fd) == -1)
perror("device close failed");
}
/*
* Writes the message on the device.
*
* Returns: 0 if something went wrong
* 1 if everything is ok
* 2 if the device returned EBUSY (used ONLY by trylock)
*/
static int
vgaarb_write(int fd, char *buf, int len)
{
int ret;
/* Just to make sure... */
buf[len] = '\0';
ret = write(fd, buf, len);
if (ret == -1) {
/* Check for EBUSY: the user may have called "trylock" and didn't get
* the lock. */
if (errno == EBUSY)
return 2;
perror("write error");
return 0;
}
else if (ret != len) {
/* The VGA arbiter implementation shouldn't receive less than one
* single message. It also shouldn't receive more. */
fprintf(stderr, "%s: write error: "
"wrote less than expected\n", __FUNCTION__);
return 0;
}
#ifdef DEBUG
fprintf(stderr, "%s: successfully wrote: '%s'\n", __FUNCTION__, buf);
#endif
return 1;
}
static const char *
rsrc_to_str(int iostate)
{
switch (iostate) {
case VGA_ARB_RSRC_LEGACY_IO | VGA_ARB_RSRC_LEGACY_MEM:
return "io+mem";
case VGA_ARB_RSRC_LEGACY_IO:
return "io";
case VGA_ARB_RSRC_LEGACY_MEM:
return "mem";
}
return "none";
}
#if 0
int
vga_arb_read(vga_arb_ptr vgaDev)
{
int ret;
char buf[BUFSIZE];
ret = read (vgaDev->fd, buf, BUFSIZE);
/* Just to make sure... */
buf[ret]='\0';
if (ret == 0) {
/* It always has something to be read. */
fprintf(stderr, "%s: error: there is nothing to read\n", __FUNCTION__);
return 0;
}
else if (ret == -1) {
perror("read error");
return 0;
}
#ifdef DEBUG
fprintf(stderr, "%s: sucessfully read: '%s'\n", __FUCNTION__, buf);
#endif
return 1;
}
#endif
int
pci_device_vgaarb_set_target(struct pci_device *dev)
{
int len;
char buf[BUFSIZE];
len = snprintf(buf, BUFSIZE, "target PCI:%d:%d:%d.%d",
dev->domain, dev->bus, dev->dev, dev->func);
return vgaarb_write(dev->vgaarb_fd, buf, len);
}
int
pci_device_vgaarb_decodes(struct pci_device *dev)
{
int len;
char buf[BUFSIZE];
len = snprintf(buf, BUFSIZE, "decodes %s", rsrc_to_str(dev->vgaarb_rsrc));
return vgaarb_write(dev->vgaarb_fd, buf, len);
}
int
pci_device_vgaarb_lock(struct pci_device *dev)
{
int len;
char buf[BUFSIZE];
len = snprintf(buf, BUFSIZE, "lock %s", rsrc_to_str(dev->vgaarb_rsrc));
return vgaarb_write(dev->vgaarb_fd, buf, len);
}
int
pci_device_vgaarb_trylock(struct pci_device *dev)
{
int len, write_ret;
char buf[BUFSIZE];
len = snprintf(buf, BUFSIZE, "trylock %s", rsrc_to_str(dev->vgaarb_rsrc));
write_ret = vgaarb_write(dev->vgaarb_fd, buf, len);
if (write_ret == 0)
return -1;
else if (write_ret == 1)
return 1;
else
/* write_ret == 2 and the lock failed */
return 0;
}
int
pci_device_vgaarb_unlock(struct pci_device *dev)
{
int len;
char buf[BUFSIZE];
len = snprintf(buf, BUFSIZE, "unlock %s", rsrc_to_str(dev->vgaarb_rsrc));
return vgaarb_write(dev->vgaarb_fd, buf, len);
}
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