freebsd-dev/sys/kern/subr_hints.c
John Baldwin 64de80195b Add a new device control utility for new-bus devices called devctl. This
allows the user to request administrative changes to individual devices
such as attach or detaching drivers or disabling and re-enabling devices.
- Add a new /dev/devctl2 character device which uses ioctls for device
  requests.  The ioctls use a common 'struct devreq' which is somewhat
  similar to 'struct ifreq'.
- The ioctls identify the device to operate on via a string.  This
  string can either by the device's name, or it can be a bus-specific
  address.  (For unattached devices, a bus address is the only way to
  locate a device.)  Bus drivers register an eventhandler to claim
  unrecognized device names that the driver recognizes as a valid address.
  Two buses currently support addresses: ACPI recognizes any device
  in the ACPI namespace via its full path starting with "\" and
  the PCI bus driver recognizes an address specification of
  'pci[<domain>:]<bus>:<slot>:<func>' (identical to the PCI selector
  strings supported by pciconf).
- To make it easier to cut and paste, change the PnP location string
  in the PCI bus driver to output a full PCI selector string rather
  than 'slot=<slot> function=<func>'.
- Add a devctl(3) interface in libdevctl which provides a wrapper around
  the ioctls and is the preferred interface for other userland code.
- Add a devctl(8) program which is a simple wrapper around the requests
  supported by devctl(3).
- Add a device_is_suspended() function to check DF_SUSPENDED.
- Add a resource_unset_value() function that can be used to remove a
  hint from the kernel environment.  This is used to clear a
  hint.<driver>.<unit>.disabled hint when re-enabling a boot-time
  disabled device.

Reviewed by:	imp (parts)
Requested by:	imp (changing PCI location string)
Relnotes:	yes
2015-02-06 16:09:01 +00:00

492 lines
11 KiB
C

/*-
* Copyright (c) 2000,2001 Peter Wemm <peter@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#include <sys/systm.h>
#include <sys/bus.h>
/*
* Access functions for device resources.
*/
static int checkmethod = 1;
static int use_kenv;
static char *hintp;
/*
* Define kern.hintmode sysctl, which only accept value 2, that cause to
* switch from Static KENV mode to Dynamic KENV. So systems that have hints
* compiled into kernel will be able to see/modify KENV (and hints too).
*/
static int
sysctl_hintmode(SYSCTL_HANDLER_ARGS)
{
const char *cp;
char *line, *eq;
int eqidx, error, from_kenv, i, value;
from_kenv = 0;
cp = kern_envp;
value = hintmode;
/* Fetch candidate for new hintmode value */
error = sysctl_handle_int(oidp, &value, 0, req);
if (error || req->newptr == NULL)
return (error);
if (value != 2)
/* Only accept swithing to hintmode 2 */
return (EINVAL);
/* Migrate from static to dynamic hints */
switch (hintmode) {
case 0:
if (dynamic_kenv) {
/*
* Already here. But assign hintmode to 2, to not
* check it in the future.
*/
hintmode = 2;
return (0);
}
from_kenv = 1;
cp = kern_envp;
break;
case 1:
cp = static_hints;
break;
case 2:
/* Nothing to do, hintmode already 2 */
return (0);
}
while (cp) {
i = strlen(cp);
if (i == 0)
break;
if (from_kenv) {
if (strncmp(cp, "hint.", 5) != 0)
/* kenv can have not only hints */
continue;
}
eq = strchr(cp, '=');
if (eq == NULL)
/* Bad hint value */
continue;
eqidx = eq - cp;
line = malloc(i+1, M_TEMP, M_WAITOK);
strcpy(line, cp);
line[eqidx] = '\0';
kern_setenv(line, line + eqidx + 1);
free(line, M_TEMP);
cp += i + 1;
}
hintmode = value;
use_kenv = 1;
return (0);
}
SYSCTL_PROC(_kern, OID_AUTO, hintmode, CTLTYPE_INT|CTLFLAG_RW,
&hintmode, 0, sysctl_hintmode, "I", "Get/set current hintmode");
/*
* Evil wildcarding resource string lookup.
* This walks the supplied env string table and returns a match.
* The start point can be remembered for incremental searches.
*/
static int
res_find(int *line, int *startln,
const char *name, int *unit, const char *resname, const char *value,
const char **ret_name, int *ret_namelen, int *ret_unit,
const char **ret_resname, int *ret_resnamelen, const char **ret_value)
{
int n = 0, hit, i = 0;
char r_name[32];
int r_unit;
char r_resname[32];
char r_value[128];
const char *s, *cp;
char *p;
if (checkmethod) {
hintp = NULL;
switch (hintmode) {
case 0: /* loader hints in environment only */
break;
case 1: /* static hints only */
hintp = static_hints;
checkmethod = 0;
break;
case 2: /* fallback mode */
if (dynamic_kenv) {
mtx_lock(&kenv_lock);
cp = kenvp[0];
for (i = 0; cp != NULL; cp = kenvp[++i]) {
if (!strncmp(cp, "hint.", 5)) {
use_kenv = 1;
checkmethod = 0;
break;
}
}
mtx_unlock(&kenv_lock);
} else {
cp = kern_envp;
while (cp) {
if (strncmp(cp, "hint.", 5) == 0) {
cp = NULL;
hintp = kern_envp;
break;
}
while (*cp != '\0')
cp++;
cp++;
if (*cp == '\0') {
cp = NULL;
hintp = static_hints;
break;
}
}
}
break;
default:
break;
}
if (hintp == NULL) {
if (dynamic_kenv) {
use_kenv = 1;
checkmethod = 0;
} else
hintp = kern_envp;
}
}
if (use_kenv) {
mtx_lock(&kenv_lock);
i = 0;
cp = kenvp[0];
if (cp == NULL) {
mtx_unlock(&kenv_lock);
return (ENOENT);
}
} else
cp = hintp;
while (cp) {
hit = 1;
(*line)++;
if (strncmp(cp, "hint.", 5) != 0)
hit = 0;
else
n = sscanf(cp, "hint.%32[^.].%d.%32[^=]=%127s",
r_name, &r_unit, r_resname, r_value);
if (hit && n != 4) {
printf("CONFIG: invalid hint '%s'\n", cp);
p = strchr(cp, 'h');
*p = 'H';
hit = 0;
}
if (hit && startln && *startln >= 0 && *line < *startln)
hit = 0;
if (hit && name && strcmp(name, r_name) != 0)
hit = 0;
if (hit && unit && *unit != r_unit)
hit = 0;
if (hit && resname && strcmp(resname, r_resname) != 0)
hit = 0;
if (hit && value && strcmp(value, r_value) != 0)
hit = 0;
if (hit)
break;
if (use_kenv) {
cp = kenvp[++i];
if (cp == NULL)
break;
} else {
while (*cp != '\0')
cp++;
cp++;
if (*cp == '\0') {
cp = NULL;
break;
}
}
}
if (use_kenv)
mtx_unlock(&kenv_lock);
if (cp == NULL)
return ENOENT;
s = cp;
/* This is a bit of a hack, but at least is reentrant */
/* Note that it returns some !unterminated! strings. */
s = strchr(s, '.') + 1; /* start of device */
if (ret_name)
*ret_name = s;
s = strchr(s, '.') + 1; /* start of unit */
if (ret_namelen && ret_name)
*ret_namelen = s - *ret_name - 1; /* device length */
if (ret_unit)
*ret_unit = r_unit;
s = strchr(s, '.') + 1; /* start of resname */
if (ret_resname)
*ret_resname = s;
s = strchr(s, '=') + 1; /* start of value */
if (ret_resnamelen && ret_resname)
*ret_resnamelen = s - *ret_resname - 1; /* value len */
if (ret_value)
*ret_value = s;
if (startln) /* line number for anchor */
*startln = *line + 1;
return 0;
}
/*
* Search all the data sources for matches to our query. We look for
* dynamic hints first as overrides for static or fallback hints.
*/
static int
resource_find(int *line, int *startln,
const char *name, int *unit, const char *resname, const char *value,
const char **ret_name, int *ret_namelen, int *ret_unit,
const char **ret_resname, int *ret_resnamelen, const char **ret_value)
{
int i;
int un;
*line = 0;
/* Search for exact unit matches first */
i = res_find(line, startln, name, unit, resname, value,
ret_name, ret_namelen, ret_unit, ret_resname, ret_resnamelen,
ret_value);
if (i == 0)
return 0;
if (unit == NULL)
return ENOENT;
/* If we are still here, search for wildcard matches */
un = -1;
i = res_find(line, startln, name, &un, resname, value,
ret_name, ret_namelen, ret_unit, ret_resname, ret_resnamelen,
ret_value);
if (i == 0)
return 0;
return ENOENT;
}
int
resource_int_value(const char *name, int unit, const char *resname, int *result)
{
int error;
const char *str;
char *op;
unsigned long val;
int line;
line = 0;
error = resource_find(&line, NULL, name, &unit, resname, NULL,
NULL, NULL, NULL, NULL, NULL, &str);
if (error)
return error;
if (*str == '\0')
return EFTYPE;
val = strtoul(str, &op, 0);
if (*op != '\0')
return EFTYPE;
*result = val;
return 0;
}
int
resource_long_value(const char *name, int unit, const char *resname,
long *result)
{
int error;
const char *str;
char *op;
unsigned long val;
int line;
line = 0;
error = resource_find(&line, NULL, name, &unit, resname, NULL,
NULL, NULL, NULL, NULL, NULL, &str);
if (error)
return error;
if (*str == '\0')
return EFTYPE;
val = strtoul(str, &op, 0);
if (*op != '\0')
return EFTYPE;
*result = val;
return 0;
}
int
resource_string_value(const char *name, int unit, const char *resname,
const char **result)
{
int error;
const char *str;
int line;
line = 0;
error = resource_find(&line, NULL, name, &unit, resname, NULL,
NULL, NULL, NULL, NULL, NULL, &str);
if (error)
return error;
*result = str;
return 0;
}
/*
* This is a bit nasty, but allows us to not modify the env strings.
*/
static const char *
resource_string_copy(const char *s, int len)
{
static char stringbuf[256];
static int offset = 0;
const char *ret;
if (len == 0)
len = strlen(s);
if (len > 255)
return NULL;
if ((offset + len + 1) > 255)
offset = 0;
bcopy(s, &stringbuf[offset], len);
stringbuf[offset + len] = '\0';
ret = &stringbuf[offset];
offset += len + 1;
return ret;
}
/*
* err = resource_find_match(&anchor, &name, &unit, resname, value)
* Iteratively fetch a list of devices wired "at" something
* res and value are restrictions. eg: "at", "scbus0".
* For practical purposes, res = required, value = optional.
* *name and *unit are set.
* set *anchor to zero before starting.
*/
int
resource_find_match(int *anchor, const char **name, int *unit,
const char *resname, const char *value)
{
const char *found_name;
int found_namelen;
int found_unit;
int ret;
int newln;
newln = *anchor;
ret = resource_find(anchor, &newln, NULL, NULL, resname, value,
&found_name, &found_namelen, &found_unit, NULL, NULL, NULL);
if (ret == 0) {
*name = resource_string_copy(found_name, found_namelen);
*unit = found_unit;
}
*anchor = newln;
return ret;
}
/*
* err = resource_find_dev(&anchor, name, &unit, res, value);
* Iterate through a list of devices, returning their unit numbers.
* res and value are optional restrictions. eg: "at", "scbus0".
* *unit is set to the value.
* set *anchor to zero before starting.
*/
int
resource_find_dev(int *anchor, const char *name, int *unit,
const char *resname, const char *value)
{
int found_unit;
int newln;
int ret;
newln = *anchor;
ret = resource_find(anchor, &newln, name, NULL, resname, value,
NULL, NULL, &found_unit, NULL, NULL, NULL);
if (ret == 0) {
*unit = found_unit;
}
*anchor = newln;
return ret;
}
/*
* Check to see if a device is disabled via a disabled hint.
*/
int
resource_disabled(const char *name, int unit)
{
int error, value;
error = resource_int_value(name, unit, "disabled", &value);
if (error)
return (0);
return (value);
}
/*
* Clear a value associated with a device by removing it from
* the kernel environment. This only removes a hint for an
* exact unit.
*/
int
resource_unset_value(const char *name, int unit, const char *resname)
{
char varname[128];
const char *retname, *retvalue;
int error, line;
size_t len;
line = 0;
error = resource_find(&line, NULL, name, &unit, resname, NULL,
&retname, NULL, NULL, NULL, NULL, &retvalue);
if (error)
return (error);
retname -= strlen("hint.");
len = retvalue - retname - 1;
if (len > sizeof(varname) - 1)
return (ENAMETOOLONG);
memcpy(varname, retname, len);
varname[len] = '\0';
return (kern_unsetenv(varname));
}