From patchwork Thu Jan 28 01:54:07 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wim Coekaerts X-Patchwork-Id: 574502 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id F2EE8140BAB for ; Thu, 28 Jan 2016 12:55:28 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932213AbcA1Bz1 (ORCPT ); Wed, 27 Jan 2016 20:55:27 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:20217 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936086AbcA1BzZ (ORCPT ); Wed, 27 Jan 2016 20:55:25 -0500 Received: from userv0021.oracle.com (userv0021.oracle.com [156.151.31.71]) by userp1040.oracle.com (Sentrion-MTA-4.3.2/Sentrion-MTA-4.3.2) with ESMTP id u0S1sbrc016376 (version=TLSv1 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Thu, 28 Jan 2016 01:54:38 GMT Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by userv0021.oracle.com (8.13.8/8.13.8) with ESMTP id u0S1saDL010986 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL); Thu, 28 Jan 2016 01:54:36 GMT Received: from abhmp0003.oracle.com (abhmp0003.oracle.com [141.146.116.9]) by userv0122.oracle.com (8.14.4/8.13.8) with ESMTP id u0S1saQv018085; Thu, 28 Jan 2016 01:54:36 GMT Received: from ca-srs1.us.oracle.com (/10.211.44.45) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 27 Jan 2016 17:54:36 -0800 From: Wim Coekaerts To: wim@iguana.be, linux@roeck-us.net Cc: linux-watchdog@vger.kernel.org, sparclinux@vger.kernel.org Subject: [PATCH] Add sun4v_wdt watchdog driver Date: Wed, 27 Jan 2016 17:54:07 -0800 Message-Id: <1453946047-18003-2-git-send-email-wim.coekaerts@oracle.com> X-Mailer: git-send-email 1.7.1 In-Reply-To: <1453946047-18003-1-git-send-email-wim.coekaerts@oracle.com> References: <1453946047-18003-1-git-send-email-wim.coekaerts@oracle.com> X-Source-IP: userv0021.oracle.com [156.151.31.71] Sender: sparclinux-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: sparclinux@vger.kernel.org This driver adds sparc hypervisor watchdog support. The default timeout is 60 seconds and the range is between 1 and 31536000 seconds. Both watchdog-resolution and watchdog-max-timeout MD properties settings are supported. Signed-off-by: Wim Coekaerts --- Change in v5: - After proper review of the hv watchdog api, the hv takes care of rounding to multiple of resolution internally so just check if it's <= 1 second. - Clean up _ping() and simplify _probe() value checking Change in v4: - timeout in seconds - call the hv with support for microsecond resolution Changes in v3: - Modify sun4v_mach_set_watchdog to allow for NULL and remove time_remaining - Cleanup includes - Consolidate _start and _ping into _ping since they were the same - Fix checkpatch warnings - Remove pr_info()s - Clean up return codes to be standard kernel return values - Consolidate _init and _probe into _init Don't use platform_device anymore because this is really just a driver that depends on a hv call. This now looks more like softdog. - Cleanly check for sun4v architecture and remove extra tests - Convert to ms timer support and honor resolution since most drivers use seconds I added _ms to make it clear - Clean up validation against the properties - Use sane values for MIN/MAX --- Documentation/watchdog/watchdog-parameters.txt | 4 + arch/sparc/kernel/hvcalls.S | 3 +- arch/sparc/kernel/sparc_ksyms_64.c | 1 + drivers/watchdog/Kconfig | 11 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/sun4v_wdt.c | 211 ++++++++++++++++++++++++ 6 files changed, 230 insertions(+), 1 deletions(-) create mode 100644 drivers/watchdog/sun4v_wdt.c diff --git a/Documentation/watchdog/watchdog-parameters.txt b/Documentation/watchdog/watchdog-parameters.txt index 9f9ec9f..4e4b6f1 100644 --- a/Documentation/watchdog/watchdog-parameters.txt +++ b/Documentation/watchdog/watchdog-parameters.txt @@ -400,3 +400,7 @@ wm8350_wdt: nowayout: Watchdog cannot be stopped once started (default=kernel config parameter) ------------------------------------------------- +sun4v_wdt: +timeout_ms: Watchdog timeout in milliseconds 1..180000, default=60000) +nowayout: Watchdog cannot be stopped once started +------------------------------------------------- diff --git a/arch/sparc/kernel/hvcalls.S b/arch/sparc/kernel/hvcalls.S index afbaba5..d127130 100644 --- a/arch/sparc/kernel/hvcalls.S +++ b/arch/sparc/kernel/hvcalls.S @@ -338,8 +338,9 @@ ENTRY(sun4v_mach_set_watchdog) mov %o1, %o4 mov HV_FAST_MACH_SET_WATCHDOG, %o5 ta HV_FAST_TRAP + brnz,a,pn %o4, 0f stx %o1, [%o4] - retl +0: retl nop ENDPROC(sun4v_mach_set_watchdog) diff --git a/arch/sparc/kernel/sparc_ksyms_64.c b/arch/sparc/kernel/sparc_ksyms_64.c index a92d5d2..9e034f2 100644 --- a/arch/sparc/kernel/sparc_ksyms_64.c +++ b/arch/sparc/kernel/sparc_ksyms_64.c @@ -37,6 +37,7 @@ EXPORT_SYMBOL(sun4v_niagara_getperf); EXPORT_SYMBOL(sun4v_niagara_setperf); EXPORT_SYMBOL(sun4v_niagara2_getperf); EXPORT_SYMBOL(sun4v_niagara2_setperf); +EXPORT_SYMBOL(sun4v_mach_set_watchdog); /* from hweight.S */ EXPORT_SYMBOL(__arch_hweight8); diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 4f0e7be..30d38ae 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1565,6 +1565,17 @@ config WATCHDOG_RIO machines. The watchdog timeout period is normally one minute but can be changed with a boot-time parameter. +config WATCHDOG_SUN4V + tristate "Sun4v Watchdog support" + select WATCHDOG_CORE + depends on SPARC64 + help + Say Y here to support the hypervisor watchdog capability embedded + in the SPARC sun4v architecture. + + To compile this driver as a module, choose M here. The module will + be called sun4v_wdt. + # XTENSA Architecture # Xen Architecture diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index f566753..f6a6a38 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -179,6 +179,7 @@ obj-$(CONFIG_SH_WDT) += shwdt.o obj-$(CONFIG_WATCHDOG_RIO) += riowd.o obj-$(CONFIG_WATCHDOG_CP1XXX) += cpwd.o +obj-$(CONFIG_WATCHDOG_SUN4V) += sun4v_wdt.o # XTENSA Architecture diff --git a/drivers/watchdog/sun4v_wdt.c b/drivers/watchdog/sun4v_wdt.c new file mode 100644 index 0000000..42da024 --- /dev/null +++ b/drivers/watchdog/sun4v_wdt.c @@ -0,0 +1,211 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include +#include + +#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 wdt_max_timeout = WDT_MAX_TIMEOUT; + +static unsigned int timeout = WDT_TIMEOUT; +module_param(timeout, uint, S_IRUGO); +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, + .identity = "sun4v hypervisor watchdog", + .firmware_version = 0, +}; + +static 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, +}; + +static int hvapi_registered; + +static int __init sun4v_wdt_init(void) +{ + struct mdesc_handle *handle; + u64 node; + const u64 *value; + u64 wdt_max_property; + u64 wdt_resolution_property; + int ret = 0; + unsigned long major = 1, minor = 1; + + /* + * This is a safe way to validate if we are on the right + * platform. + */ + if (sun4v_hvapi_register(HV_GRP_CORE, major, &minor) != 0) + return -ENODEV; + if (minor < 1) { + sun4v_hvapi_unregister(HV_GRP_CORE); + return -ENODEV; + } + hvapi_registered = 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"); + if (node == MDESC_NODE_NULL) { + mdesc_release(handle); + sun4v_hvapi_unregister(HV_GRP_CORE); + return -ENODEV; + } + + /* Allow for resolution up to 1s (default) */ + value = mdesc_get_property(handle, node, "watchdog-resolution", NULL); + if (value) { + wdt_resolution_property = *value; + if (wdt_resolution_property == 0 || + wdt_resolution_property > WDT_DEFAULT_RESOLUTION_MS) { + mdesc_release(handle); + sun4v_hvapi_unregister(HV_GRP_CORE); + return -EINVAL; + } + } + + value = mdesc_get_property(handle, node, "watchdog-max-timeout", NULL); + if (value) { + wdt_max_property = *value; + /* + * If the property (in ms) is set to a value smaller than + * WDT_MIN_TIMEOUT, return -EINVAL. + */ + if (wdt_max_property < (WDT_MIN_TIMEOUT * 1000)) { + mdesc_release(handle); + sun4v_hvapi_unregister(HV_GRP_CORE); + return -EINVAL; + } + + /* + * If the property is set to a value smaller than + * WDT_MAX_TIMEOUT then set wdt_max_timeout to + * the value of the property in seconds. + */ + if (wdt_max_property < (wdt_max_timeout * 1000)) + wdt_max_timeout = wdt_max_property / 1000; + } + + mdesc_release(handle); + + if (timeout < WDT_MIN_TIMEOUT) + timeout = WDT_MIN_TIMEOUT; + if (timeout > wdt_max_timeout) + timeout = wdt_max_timeout; + + wdd.max_timeout = wdt_max_timeout; + wdd.timeout = timeout; + + watchdog_set_nowayout(&wdd, nowayout); + + ret = watchdog_register_device(&wdd); + if (ret) { + sun4v_hvapi_unregister(HV_GRP_CORE); + return ret; + } + + pr_info("initialized (timeout=%dms, nowayout=%d)\n", + wdd.timeout, nowayout); + + return 0; +} + + +static void __exit sun4v_wdt_exit(void) +{ + if (hvapi_registered) + sun4v_hvapi_unregister(HV_GRP_CORE); + sun4v_wdt_stop(&wdd); + watchdog_unregister_device(&wdd); +} + +module_init(sun4v_wdt_init); +module_exit(sun4v_wdt_exit); + +MODULE_AUTHOR("Wim Coekaerts "); +MODULE_DESCRIPTION("sun4v watchdog driver"); +MODULE_LICENSE("GPL");