/* * Copyright (C) 2015 Broadcom Corporation * * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include #include #include #include #include #include #include #define WDT_START_1 0xff00 #define WDT_START_2 0x00ff #define WDT_STOP_1 0xee00 #define WDT_STOP_2 0x00ee #define WDT_TIMEOUT_REG 0x0 #define WDT_CMD_REG 0x4 #define WDT_MIN_TIMEOUT 1 /* seconds */ #define WDT_DEFAULT_TIMEOUT 30 /* seconds */ #define WDT_DEFAULT_RATE 27000000 struct bcm7038_watchdog { void __iomem *base; struct watchdog_device wdd; u32 rate; struct clk *clk; }; static bool nowayout = WATCHDOG_NOWAYOUT; static void bcm7038_wdt_set_timeout_reg(struct watchdog_device *wdog) { struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); u32 timeout; timeout = wdt->rate * wdog->timeout; writel(timeout, wdt->base + WDT_TIMEOUT_REG); } static int bcm7038_wdt_ping(struct watchdog_device *wdog) { struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); writel(WDT_START_1, wdt->base + WDT_CMD_REG); writel(WDT_START_2, wdt->base + WDT_CMD_REG); return 0; } static int bcm7038_wdt_start(struct watchdog_device *wdog) { bcm7038_wdt_set_timeout_reg(wdog); bcm7038_wdt_ping(wdog); return 0; } static int bcm7038_wdt_stop(struct watchdog_device *wdog) { struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); writel(WDT_STOP_1, wdt->base + WDT_CMD_REG); writel(WDT_STOP_2, wdt->base + WDT_CMD_REG); return 0; } static int bcm7038_wdt_set_timeout(struct watchdog_device *wdog, unsigned int t) { /* Can't modify timeout value if watchdog timer is running */ bcm7038_wdt_stop(wdog); wdog->timeout = t; bcm7038_wdt_start(wdog); return 0; } static unsigned int bcm7038_wdt_get_timeleft(struct watchdog_device *wdog) { struct bcm7038_watchdog *wdt = watchdog_get_drvdata(wdog); u32 time_left; time_left = readl(wdt->base + WDT_CMD_REG); return time_left / wdt->rate; } static struct watchdog_info bcm7038_wdt_info = { .identity = "Broadcom BCM7038 Watchdog Timer", .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE }; static const struct watchdog_ops bcm7038_wdt_ops = { .owner = THIS_MODULE, .start = bcm7038_wdt_start, .stop = bcm7038_wdt_stop, .set_timeout = bcm7038_wdt_set_timeout, .get_timeleft = bcm7038_wdt_get_timeleft, }; static int bcm7038_wdt_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct bcm7038_watchdog *wdt; struct resource *res; int err; wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; platform_set_drvdata(pdev, wdt); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); wdt->base = devm_ioremap_resource(dev, res); if (IS_ERR(wdt->base)) return PTR_ERR(wdt->base); wdt->clk = devm_clk_get(dev, NULL); /* If unable to get clock, use default frequency */ if (!IS_ERR(wdt->clk)) { clk_prepare_enable(wdt->clk); wdt->rate = clk_get_rate(wdt->clk); /* Prevent divide-by-zero exception */ if (!wdt->rate) wdt->rate = WDT_DEFAULT_RATE; } else { wdt->rate = WDT_DEFAULT_RATE; wdt->clk = NULL; } wdt->wdd.info = &bcm7038_wdt_info; wdt->wdd.ops = &bcm7038_wdt_ops; wdt->wdd.min_timeout = WDT_MIN_TIMEOUT; wdt->wdd.timeout = WDT_DEFAULT_TIMEOUT; wdt->wdd.max_timeout = 0xffffffff / wdt->rate; wdt->wdd.parent = dev; watchdog_set_drvdata(&wdt->wdd, wdt); err = watchdog_register_device(&wdt->wdd); if (err) { dev_err(dev, "Failed to register watchdog device\n"); clk_disable_unprepare(wdt->clk); return err; } dev_info(dev, "Registered BCM7038 Watchdog\n"); return 0; } static int bcm7038_wdt_remove(struct platform_device *pdev) { struct bcm7038_watchdog *wdt = platform_get_drvdata(pdev); if (!nowayout) bcm7038_wdt_stop(&wdt->wdd); watchdog_unregister_device(&wdt->wdd); clk_disable_unprepare(wdt->clk); return 0; } #ifdef CONFIG_PM_SLEEP static int bcm7038_wdt_suspend(struct device *dev) { struct bcm7038_watchdog *wdt = dev_get_drvdata(dev); if (watchdog_active(&wdt->wdd)) return bcm7038_wdt_stop(&wdt->wdd); return 0; } static int bcm7038_wdt_resume(struct device *dev) { struct bcm7038_watchdog *wdt = dev_get_drvdata(dev); if (watchdog_active(&wdt->wdd)) return bcm7038_wdt_start(&wdt->wdd); return 0; } #endif static SIMPLE_DEV_PM_OPS(bcm7038_wdt_pm_ops, bcm7038_wdt_suspend, bcm7038_wdt_resume); static void bcm7038_wdt_shutdown(struct platform_device *pdev) { struct bcm7038_watchdog *wdt = platform_get_drvdata(pdev); if (watchdog_active(&wdt->wdd)) bcm7038_wdt_stop(&wdt->wdd); } static const struct of_device_id bcm7038_wdt_match[] = { { .compatible = "brcm,bcm7038-wdt" }, {}, }; MODULE_DEVICE_TABLE(of, bcm7038_wdt_match); static struct platform_driver bcm7038_wdt_driver = { .probe = bcm7038_wdt_probe, .remove = bcm7038_wdt_remove, .shutdown = bcm7038_wdt_shutdown, .driver = { .name = "bcm7038-wdt", .of_match_table = bcm7038_wdt_match, .pm = &bcm7038_wdt_pm_ops, } }; module_platform_driver(bcm7038_wdt_driver); module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Driver for Broadcom 7038 SoCs Watchdog"); MODULE_AUTHOR("Justin Chen"); 966d79d4c6529a5f7b9206e405 (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 'fs/xfs/libxfs/xfs_attr_remote.c')