linux/drivers/watchdog/sun4v_wdt.c
Bhumika Goyal b893e344bf watchdog: constify watchdog_ops structures
Declare watchdog_ops structures as const as they are only stored in the
ops field of a watchdog_device structure. This field is of type const, so
watchdog_ops structures having this property can be made const too.
Done using Coccinelle:

@r disable optional_qualifier@
identifier x;
position p;
@@
static struct watchdog_ops x@p={...};

@ok@
struct watchdog_device w;
identifier r.x;
position p;
@@
w.ops=&x@p;

@bad@
position p != {r.p,ok.p};
identifier r.x;
@@
x@p

@depends on !bad disable optional_qualifier@
identifier r.x;
@@
+const
struct watchdog_ops x;

File size details before and after patching.
First line of every .o file shows the file size before patching
and second line shows the size after patching.

   text    data     bss     dec     hex filename

   1340	    544	      0	   1884	    75c	drivers/watchdog/bcm_kona_wdt.o
   1436	    440	      0	   1876	    754	drivers/watchdog/bcm_kona_wdt.o

   1176	    544	      4	   1724	    6bc	drivers/watchdog/digicolor_wdt.o
   1272	    440	      4	   1716	    6b4	drivers/watchdog/digicolor_wdt.o

    925	    580	     89	   1594	    63a	drivers/watchdog/ep93xx_wdt.o
   1021	    476	     89	   1586	    632	drivers/watchdog/ep93xx_wdt.o

   4932	    288	     17	   5237	   1475	drivers/watchdog/s3c2410_wdt.o
   5028	    192	     17	   5237	   1475	drivers/watchdog/s3c2410_wdt.o

   1977	    292	      1	   2270	    8de	drivers/watchdog/sama5d4_wdt.o
   2073	    196	      1	   2270	    8de	drivers/watchdog/sama5d4_wdt.o

   1375	    484	      1	   1860	    744	drivers/watchdog/sirfsoc_wdt.o
   1471	    380	      1	   1852	    73c	drivers/watchdog/sirfsoc_wdt.o

Size remains the same for the files drivers/watchdog/diag288_wdt.o
drivers/watchdog/asm9260_wdt.o and drivers/watchdog/atlas7_wdt.o

The following .o files did not compile:
drivers/watchdog/sun4v_wdt.o, drivers/watchdog/sbsa_gwdt.o,
drivers/watchdog/rt2880_wdt.o, drivers/watchdog/booke_wdt.o
drivers/watchdog/mt7621_wdt.o

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-02-24 14:00:23 -08:00

192 lines
4.5 KiB
C

/*
* sun4v watchdog timer
* (c) Copyright 2016 Oracle Corporation
*
* Implement a simple watchdog driver using the built-in sun4v hypervisor
* watchdog support. If time expires, the hypervisor stops or bounces
* the guest domain.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/watchdog.h>
#include <asm/hypervisor.h>
#include <asm/mdesc.h>
#define WDT_TIMEOUT 60
#define WDT_MAX_TIMEOUT 31536000
#define WDT_MIN_TIMEOUT 1
#define WDT_DEFAULT_RESOLUTION_MS 1000 /* 1 second */
static unsigned int timeout;
module_param(timeout, uint, 0);
MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds (default="
__MODULE_STRING(WDT_TIMEOUT) ")");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, S_IRUGO);
MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static int sun4v_wdt_stop(struct watchdog_device *wdd)
{
sun4v_mach_set_watchdog(0, NULL);
return 0;
}
static int sun4v_wdt_ping(struct watchdog_device *wdd)
{
int hverr;
/*
* HV watchdog timer will round up the timeout
* passed in to the nearest multiple of the
* watchdog resolution in milliseconds.
*/
hverr = sun4v_mach_set_watchdog(wdd->timeout * 1000, NULL);
if (hverr == HV_EINVAL)
return -EINVAL;
return 0;
}
static int sun4v_wdt_set_timeout(struct watchdog_device *wdd,
unsigned int timeout)
{
wdd->timeout = timeout;
return 0;
}
static const struct watchdog_info sun4v_wdt_ident = {
.options = WDIOF_SETTIMEOUT |
WDIOF_MAGICCLOSE |
WDIOF_KEEPALIVEPING,
.identity = "sun4v hypervisor watchdog",
.firmware_version = 0,
};
static const struct watchdog_ops sun4v_wdt_ops = {
.owner = THIS_MODULE,
.start = sun4v_wdt_ping,
.stop = sun4v_wdt_stop,
.ping = sun4v_wdt_ping,
.set_timeout = sun4v_wdt_set_timeout,
};
static struct watchdog_device wdd = {
.info = &sun4v_wdt_ident,
.ops = &sun4v_wdt_ops,
.min_timeout = WDT_MIN_TIMEOUT,
.max_timeout = WDT_MAX_TIMEOUT,
.timeout = WDT_TIMEOUT,
};
static int __init sun4v_wdt_init(void)
{
struct mdesc_handle *handle;
u64 node;
const u64 *value;
int err = 0;
unsigned long major = 1, minor = 1;
/*
* There are 2 properties that can be set from the control
* domain for the watchdog.
* watchdog-resolution
* watchdog-max-timeout
*
* We can expect a handle to be returned otherwise something
* serious is wrong. Correct to return -ENODEV here.
*/
handle = mdesc_grab();
if (!handle)
return -ENODEV;
node = mdesc_node_by_name(handle, MDESC_NODE_NULL, "platform");
err = -ENODEV;
if (node == MDESC_NODE_NULL)
goto out_release;
/*
* This is a safe way to validate if we are on the right
* platform.
*/
if (sun4v_hvapi_register(HV_GRP_CORE, major, &minor))
goto out_hv_unreg;
/* Allow value of watchdog-resolution up to 1s (default) */
value = mdesc_get_property(handle, node, "watchdog-resolution", NULL);
err = -EINVAL;
if (value) {
if (*value == 0 ||
*value > WDT_DEFAULT_RESOLUTION_MS)
goto out_hv_unreg;
}
value = mdesc_get_property(handle, node, "watchdog-max-timeout", NULL);
if (value) {
/*
* If the property value (in ms) is smaller than
* min_timeout, return -EINVAL.
*/
if (*value < wdd.min_timeout * 1000)
goto out_hv_unreg;
/*
* If the property value is smaller than
* default max_timeout then set watchdog max_timeout to
* the value of the property in seconds.
*/
if (*value < wdd.max_timeout * 1000)
wdd.max_timeout = *value / 1000;
}
watchdog_init_timeout(&wdd, timeout, NULL);
watchdog_set_nowayout(&wdd, nowayout);
err = watchdog_register_device(&wdd);
if (err)
goto out_hv_unreg;
pr_info("initialized (timeout=%ds, nowayout=%d)\n",
wdd.timeout, nowayout);
mdesc_release(handle);
return 0;
out_hv_unreg:
sun4v_hvapi_unregister(HV_GRP_CORE);
out_release:
mdesc_release(handle);
return err;
}
static void __exit sun4v_wdt_exit(void)
{
sun4v_hvapi_unregister(HV_GRP_CORE);
watchdog_unregister_device(&wdd);
}
module_init(sun4v_wdt_init);
module_exit(sun4v_wdt_exit);
MODULE_AUTHOR("Wim Coekaerts <wim.coekaerts@oracle.com>");
MODULE_DESCRIPTION("sun4v watchdog driver");
MODULE_LICENSE("GPL");