/* * Watchdog driver for CSR Atlas7 * * Copyright (c) 2015 Cambridge Silicon Radio Limited, a CSR plc group company. * * Licensed under GPLv2. */ #include #include #include #include #include #include #include #define ATLAS7_TIMER_WDT_INDEX 5 #define ATLAS7_WDT_DEFAULT_TIMEOUT 20 #define ATLAS7_WDT_CNT_CTRL (0 + 4 * ATLAS7_TIMER_WDT_INDEX) #define ATLAS7_WDT_CNT_MATCH (0x18 + 4 * ATLAS7_TIMER_WDT_INDEX) #define ATLAS7_WDT_CNT (0x48 + 4 * ATLAS7_TIMER_WDT_INDEX) #define ATLAS7_WDT_CNT_EN (BIT(0) | BIT(1)) #define ATLAS7_WDT_EN 0x64 static unsigned int timeout = ATLAS7_WDT_DEFAULT_TIMEOUT; static bool nowayout = WATCHDOG_NOWAYOUT; module_param(timeout, uint, 0); module_param(nowayout, bool, 0); MODULE_PARM_DESC(timeout, "Default watchdog timeout (in seconds)"); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); struct atlas7_wdog { struct device *dev; void __iomem *base; unsigned long tick_rate; struct clk *clk; }; static unsigned int atlas7_wdt_gettimeleft(struct watchdog_device *wdd) { struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); u32 counter, match, delta; counter = readl(wdt->base + ATLAS7_WDT_CNT); match = readl(wdt->base + ATLAS7_WDT_CNT_MATCH); delta = match - counter; return delta / wdt->tick_rate; } static int atlas7_wdt_ping(struct watchdog_device *wdd) { struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); u32 counter, match, delta; counter = readl(wdt->base + ATLAS7_WDT_CNT); delta = wdd->timeout * wdt->tick_rate; match = counter + delta; writel(match, wdt->base + ATLAS7_WDT_CNT_MATCH); return 0; } static int atlas7_wdt_enable(struct watchdog_device *wdd) { struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); atlas7_wdt_ping(wdd); writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) | ATLAS7_WDT_CNT_EN, wdt->base + ATLAS7_WDT_CNT_CTRL); writel(1, wdt->base + ATLAS7_WDT_EN); return 0; } static int atlas7_wdt_disable(struct watchdog_device *wdd) { struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); writel(0, wdt->base + ATLAS7_WDT_EN); writel(readl(wdt->base + ATLAS7_WDT_CNT_CTRL) & ~ATLAS7_WDT_CNT_EN, wdt->base + ATLAS7_WDT_CNT_CTRL); return 0; } static int atlas7_wdt_settimeout(struct watchdog_device *wdd, unsigned int to) { wdd->timeout = to; return 0; } #define OPTIONS (WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE) static const struct watchdog_info atlas7_wdt_ident = { .options = OPTIONS, .firmware_version = 0, .identity = "atlas7 Watchdog", }; static struct watchdog_ops atlas7_wdt_ops = { .owner = THIS_MODULE, .start = atlas7_wdt_enable, .stop = atlas7_wdt_disable, .get_timeleft = atlas7_wdt_gettimeleft, .ping = atlas7_wdt_ping, .set_timeout = atlas7_wdt_settimeout, }; static struct watchdog_device atlas7_wdd = { .info = &atlas7_wdt_ident, .ops = &atlas7_wdt_ops, .timeout = ATLAS7_WDT_DEFAULT_TIMEOUT, }; static const struct of_device_id atlas7_wdt_ids[] = { { .compatible = "sirf,atlas7-tick"}, {} }; static int atlas7_wdt_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct atlas7_wdog *wdt; struct resource *res; struct clk *clk; int ret; wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); wdt->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(wdt->base)) return PTR_ERR(wdt->base); clk = of_clk_get(np, 0); if (IS_ERR(clk)) return PTR_ERR(clk); ret = clk_prepare_enable(clk); if (ret) { dev_err(&pdev->dev, "clk enable failed\n"); goto err; } /* disable watchdog hardware */ writel(0, wdt->base + ATLAS7_WDT_CNT_CTRL); wdt->tick_rate = clk_get_rate(clk); if (!wdt->tick_rate) { ret = -EINVAL; goto err1; } wdt->clk = clk; atlas7_wdd.min_timeout = 1; atlas7_wdd.max_timeout = UINT_MAX / wdt->tick_rate; watchdog_init_timeout(&atlas7_wdd, 0, &pdev->dev); watchdog_set_nowayout(&atlas7_wdd, nowayout); watchdog_set_drvdata(&atlas7_wdd, wdt); platform_set_drvdata(pdev, &atlas7_wdd); ret = watchdog_register_device(&atlas7_wdd); if (ret) goto err1; return 0; err1: clk_disable_unprepare(clk); err: clk_put(clk); return ret; } static void atlas7_wdt_shutdown(struct platform_device *pdev) { struct watchdog_device *wdd = platform_get_drvdata(pdev); struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); atlas7_wdt_disable(wdd); clk_disable_unprepare(wdt->clk); } static int atlas7_wdt_remove(struct platform_device *pdev) { struct watchdog_device *wdd = platform_get_drvdata(pdev); struct atlas7_wdog *wdt = watchdog_get_drvdata(wdd); atlas7_wdt_shutdown(pdev); clk_put(wdt->clk); return 0; } static int __maybe_unused atlas7_wdt_suspend(struct device *dev) { /* * NOTE:timer controller registers settings are saved * and restored back by the timer-atlas7.c */ return 0; } static int __maybe_unused atlas7_wdt_resume(struct device *dev) { struct watchdog_device *wdd = dev_get_drvdata(dev); /* * NOTE: Since timer controller registers settings are saved * and restored back by the timer-atlas7.c, so we need not * update WD settings except refreshing timeout. */ atlas7_wdt_ping(wdd); return 0; } static SIMPLE_DEV_PM_OPS(atlas7_wdt_pm_ops, atlas7_wdt_suspend, atlas7_wdt_resume); MODULE_DEVICE_TABLE(of, atlas7_wdt_ids); static struct platform_driver atlas7_wdt_driver = { .driver = { .name = "atlas7-wdt", .pm = &atlas7_wdt_pm_ops, .of_match_table = atlas7_wdt_ids, }, .probe = atlas7_wdt_probe, .remove = atlas7_wdt_remove, .shutdown = atlas7_wdt_shutdown, }; module_platform_driver(atlas7_wdt_driver); MODULE_DESCRIPTION("CSRatlas7 watchdog driver"); MODULE_AUTHOR("Guo Zeng "); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:atlas7-wdt"); ove&id=39cb2c9a316e77f6dfba96c543e55b6672d5a37e'>tools/perf/ui/util.h parent2c5d9555d6d937966d79d4c6529a5f7b9206e405 (diff)
drm/i915: Check for NULL i915_vma in intel_unpin_fb_obj()
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'tools/perf/ui/util.h')