/* * Ralink MT7621/MT7628 built-in hardware watchdog timer * * Copyright (C) 2014 John Crispin * * This driver was based on: drivers/watchdog/rt2880_wdt.c * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. */ #include #include #include #include #include #include #include #include #define SYSC_RSTSTAT 0x38 #define WDT_RST_CAUSE BIT(1) #define RALINK_WDT_TIMEOUT 30 #define TIMER_REG_TMRSTAT 0x00 #define TIMER_REG_TMR1LOAD 0x24 #define TIMER_REG_TMR1CTL 0x20 #define TMR1CTL_ENABLE BIT(7) #define TMR1CTL_RESTART BIT(9) #define TMR1CTL_PRESCALE_SHIFT 16 static void __iomem *mt7621_wdt_base; static struct reset_control *mt7621_wdt_reset; static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); static inline void rt_wdt_w32(unsigned reg, u32 val) { iowrite32(val, mt7621_wdt_base + reg); } static inline u32 rt_wdt_r32(unsigned reg) { return ioread32(mt7621_wdt_base + reg); } static int mt7621_wdt_ping(struct watchdog_device *w) { rt_wdt_w32(TIMER_REG_TMRSTAT, TMR1CTL_RESTART); return 0; } static int mt7621_wdt_set_timeout(struct watchdog_device *w, unsigned int t) { w->timeout = t; rt_wdt_w32(TIMER_REG_TMR1LOAD, t * 1000); mt7621_wdt_ping(w); return 0; } static int mt7621_wdt_start(struct watchdog_device *w) { u32 t; /* set the prescaler to 1ms == 1000us */ rt_wdt_w32(TIMER_REG_TMR1CTL, 1000 << TMR1CTL_PRESCALE_SHIFT); mt7621_wdt_set_timeout(w, w->timeout); t = rt_wdt_r32(TIMER_REG_TMR1CTL); t |= TMR1CTL_ENABLE; rt_wdt_w32(TIMER_REG_TMR1CTL, t); return 0; } static int mt7621_wdt_stop(struct watchdog_device *w) { u32 t; mt7621_wdt_ping(w); t = rt_wdt_r32(TIMER_REG_TMR1CTL); t &= ~TMR1CTL_ENABLE; rt_wdt_w32(TIMER_REG_TMR1CTL, t); return 0; } static int mt7621_wdt_bootcause(void) { if (rt_sysc_r32(SYSC_RSTSTAT) & WDT_RST_CAUSE) return WDIOF_CARDRESET; return 0; } static struct watchdog_info mt7621_wdt_info = { .identity = "Mediatek Watchdog", .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, }; static struct watchdog_ops mt7621_wdt_ops = { .owner = THIS_MODULE, .start = mt7621_wdt_start, .stop = mt7621_wdt_stop, .ping = mt7621_wdt_ping, .set_timeout = mt7621_wdt_set_timeout, }; static struct watchdog_device mt7621_wdt_dev = { .info = &mt7621_wdt_info, .ops = &mt7621_wdt_ops, .min_timeout = 1, .max_timeout = 0xfffful / 1000, }; static int mt7621_wdt_probe(struct platform_device *pdev) { struct resource *res; int ret; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); mt7621_wdt_base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(mt7621_wdt_base)) return PTR_ERR(mt7621_wdt_base); mt7621_wdt_reset = devm_reset_control_get(&pdev->dev, NULL); if (!IS_ERR(mt7621_wdt_reset)) reset_control_deassert(mt7621_wdt_reset); mt7621_wdt_dev.bootstatus = mt7621_wdt_bootcause(); watchdog_init_timeout(&mt7621_wdt_dev, mt7621_wdt_dev.max_timeout, &pdev->dev); watchdog_set_nowayout(&mt7621_wdt_dev, nowayout); ret = watchdog_register_device(&mt7621_wdt_dev); return 0; } static int mt7621_wdt_remove(struct platform_device *pdev) { watchdog_unregister_device(&mt7621_wdt_dev); return 0; } static void mt7621_wdt_shutdown(struct platform_device *pdev) { mt7621_wdt_stop(&mt7621_wdt_dev); } static const struct of_device_id mt7621_wdt_match[] = { { .compatible = "mediatek,mt7621-wdt" }, {}, }; MODULE_DEVICE_TABLE(of, mt7621_wdt_match); static struct platform_driver mt7621_wdt_driver = { .probe = mt7621_wdt_probe, .remove = mt7621_wdt_remove, .shutdown = mt7621_wdt_shutdown, .driver = { .name = KBUILD_MODNAME, .of_match_table = mt7621_wdt_match, }, }; module_platform_driver(mt7621_wdt_driver); MODULE_DESCRIPTION("MediaTek MT762x hardware watchdog driver"); MODULE_AUTHOR("John Crispin 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 /drivers/usb/phy/phy-am335x.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 'drivers/usb/phy/phy-am335x.c')