/* * Watchdog driver for Cirrus Logic EP93xx family of devices. * * Copyright (c) 2004 Ray Lehtiniemi * Copyright (c) 2006 Tower Technologies * Based on ep93xx driver, bits from alim7101_wdt.c * * Authors: Ray Lehtiniemi , * Alessandro Zummo * * Copyright (c) 2012 H Hartley Sweeten * Convert to a platform device and use the watchdog framework API * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. * * This watchdog fires after 250msec, which is a too short interval * for us to rely on the user space daemon alone. So we ping the * wdt each ~200msec and eventually stop doing it if the user space * daemon dies. * * TODO: * * - Test last reset from watchdog status * - Add a few missing ioctls */ #include #include #include #include #include #define WDT_VERSION "0.4" /* default timeout (secs) */ #define WDT_TIMEOUT 30 static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started"); static unsigned int timeout = WDT_TIMEOUT; module_param(timeout, uint, 0); MODULE_PARM_DESC(timeout, "Watchdog timeout in seconds. (1<=timeout<=3600, default=" __MODULE_STRING(WDT_TIMEOUT) ")"); static void __iomem *mmio_base; static struct timer_list timer; static unsigned long next_heartbeat; #define EP93XX_WATCHDOG 0x00 #define EP93XX_WDSTATUS 0x04 /* reset the wdt every ~200ms - the heartbeat of the device is 0.250 seconds*/ #define WDT_INTERVAL (HZ/5) static void ep93xx_wdt_timer_ping(unsigned long data) { if (time_before(jiffies, next_heartbeat)) writel(0x5555, mmio_base + EP93XX_WATCHDOG); /* Re-set the timer interval */ mod_timer(&timer, jiffies + WDT_INTERVAL); } static int ep93xx_wdt_start(struct watchdog_device *wdd) { next_heartbeat = jiffies + (timeout * HZ); writel(0xaaaa, mmio_base + EP93XX_WATCHDOG); mod_timer(&timer, jiffies + WDT_INTERVAL); return 0; } static int ep93xx_wdt_stop(struct watchdog_device *wdd) { del_timer_sync(&timer); writel(0xaa55, mmio_base + EP93XX_WATCHDOG); return 0; } static int ep93xx_wdt_keepalive(struct watchdog_device *wdd) { /* user land ping */ next_heartbeat = jiffies + (timeout * HZ); return 0; } static const struct watchdog_info ep93xx_wdt_ident = { .options = WDIOF_CARDRESET | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING, .identity = "EP93xx Watchdog", }; static struct watchdog_ops ep93xx_wdt_ops = { .owner = THIS_MODULE, .start = ep93xx_wdt_start, .stop = ep93xx_wdt_stop, .ping = ep93xx_wdt_keepalive, }; static struct watchdog_device ep93xx_wdt_wdd = { .info = &ep93xx_wdt_ident, .ops = &ep93xx_wdt_ops, }; static int ep93xx_wdt_probe(struct platform_device *pdev) { struct resource *res; unsigned long val; int err; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); mmio_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(mmio_base)) return PTR_ERR(mmio_base); if (timeout < 1 || timeout > 3600) { timeout = WDT_TIMEOUT; dev_warn(&pdev->dev, "timeout value must be 1<=x<=3600, using %d\n", timeout); } val = readl(mmio_base + EP93XX_WATCHDOG); ep93xx_wdt_wdd.bootstatus = (val & 0x01) ? WDIOF_CARDRESET : 0; ep93xx_wdt_wdd.timeout = timeout; ep93xx_wdt_wdd.parent = &pdev->dev; watchdog_set_nowayout(&ep93xx_wdt_wdd, nowayout); setup_timer(&timer, ep93xx_wdt_timer_ping, 1); err = watchdog_register_device(&ep93xx_wdt_wdd); if (err) return err; dev_info(&pdev->dev, "EP93XX watchdog, driver version " WDT_VERSION "%s\n", (val & 0x08) ? " (nCS1 disable detected)" : ""); return 0; } static int ep93xx_wdt_remove(struct platform_device *pdev) { watchdog_unregister_device(&ep93xx_wdt_wdd); return 0; } static struct platform_driver ep93xx_wdt_driver = { .driver = { .name = "ep93xx-wdt", }, .probe = ep93xx_wdt_probe, .remove = ep93xx_wdt_remove, }; module_platform_driver(ep93xx_wdt_driver); MODULE_AUTHOR("Ray Lehtiniemi "); MODULE_AUTHOR("Alessandro Zummo "); MODULE_AUTHOR("H Hartley Sweeten "); MODULE_DESCRIPTION("EP93xx Watchdog"); MODULE_LICENSE("GPL"); MODULE_VERSION(WDT_VERSION); 35space:mode:
authorArd Biesheuvel <ard.biesheuvel@linaro.org>2017-02-01 17:45:02 +0000
committerIngo Molnar <mingo@kernel.org>2017-02-01 21:17:49 +0100
commitc8f325a59cfc718d13a50fbc746ed9b415c25e92 (patch)
treed53fbdac9d0781e39a13b2ac6b2bd258cf3b4140 /sound/soc/img/img-spdif-in.c
parentbf29bddf0417a4783da3b24e8c9e017ac649326f (diff)
efi/fdt: Avoid FDT manipulation after ExitBootServices()
Some AArch64 UEFI implementations disable the MMU in ExitBootServices(), after which unaligned accesses to RAM are no longer supported. Commit: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") fixed an issue in the memory map handling of the stub FDT code, but inadvertently created an issue with such firmware, by moving some of the FDT manipulation to after the invocation of ExitBootServices(). Given that the stub's libfdt implementation uses the ordinary, accelerated string functions, which rely on hardware handling of unaligned accesses, manipulating the FDT with the MMU off may result in alignment faults. So fix the situation by moving the update_fdt_memmap() call into the callback function invoked by efi_exit_boot_services() right before it calls the ExitBootServices() UEFI service (which is arguably a better place for it anyway) Note that disabling the MMU in ExitBootServices() is not compliant with the UEFI spec, and carries great risk due to the fact that switching from cached to uncached memory accesses halfway through compiler generated code (i.e., involving a stack) can never be done in a way that is architecturally safe. Fixes: abfb7b686a3e ("efi/libstub/arm*: Pass latest memory map to the kernel") Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Tested-by: Riku Voipio <riku.voipio@linaro.org> Cc: <stable@vger.kernel.org> Cc: mark.rutland@arm.com Cc: linux-efi@vger.kernel.org Cc: matt@codeblueprint.co.uk Cc: leif.lindholm@linaro.org Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/1485971102-23330-2-git-send-email-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'sound/soc/img/img-spdif-in.c')