/* * Maxim MAX77620 Watchdog Driver * * Copyright (C) 2016 NVIDIA CORPORATION. All rights reserved. * * Author: Laxman Dewangan * * 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 #include static bool nowayout = WATCHDOG_NOWAYOUT; struct max77620_wdt { struct device *dev; struct regmap *rmap; struct watchdog_device wdt_dev; }; static int max77620_wdt_start(struct watchdog_device *wdt_dev) { struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, MAX77620_WDTEN, MAX77620_WDTEN); } static int max77620_wdt_stop(struct watchdog_device *wdt_dev) { struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, MAX77620_WDTEN, 0); } static int max77620_wdt_ping(struct watchdog_device *wdt_dev) { struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); return regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3, MAX77620_WDTC_MASK, 0x1); } static int max77620_wdt_set_timeout(struct watchdog_device *wdt_dev, unsigned int timeout) { struct max77620_wdt *wdt = watchdog_get_drvdata(wdt_dev); unsigned int wdt_timeout; u8 regval; int ret; switch (timeout) { case 0 ... 2: regval = MAX77620_TWD_2s; wdt_timeout = 2; break; case 3 ... 16: regval = MAX77620_TWD_16s; wdt_timeout = 16; break; case 17 ... 64: regval = MAX77620_TWD_64s; wdt_timeout = 64; break; default: regval = MAX77620_TWD_128s; wdt_timeout = 128; break; } ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL3, MAX77620_WDTC_MASK, 0x1); if (ret < 0) return ret; ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, MAX77620_TWD_MASK, regval); if (ret < 0) return ret; wdt_dev->timeout = wdt_timeout; return 0; } static const struct watchdog_info max77620_wdt_info = { .identity = "max77620-watchdog", .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, }; static const struct watchdog_ops max77620_wdt_ops = { .start = max77620_wdt_start, .stop = max77620_wdt_stop, .ping = max77620_wdt_ping, .set_timeout = max77620_wdt_set_timeout, }; static int max77620_wdt_probe(struct platform_device *pdev) { struct max77620_wdt *wdt; struct watchdog_device *wdt_dev; unsigned int regval; int ret; wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) return -ENOMEM; wdt->dev = &pdev->dev; wdt->rmap = dev_get_regmap(pdev->dev.parent, NULL); if (!wdt->rmap) { dev_err(wdt->dev, "Failed to get parent regmap\n"); return -ENODEV; } wdt_dev = &wdt->wdt_dev; wdt_dev->info = &max77620_wdt_info; wdt_dev->ops = &max77620_wdt_ops; wdt_dev->min_timeout = 2; wdt_dev->max_timeout = 128; wdt_dev->max_hw_heartbeat_ms = 128 * 1000; platform_set_drvdata(pdev, wdt); /* Enable WD_RST_WK - WDT expire results in a restart */ ret = regmap_update_bits(wdt->rmap, MAX77620_REG_ONOFFCNFG2, MAX77620_ONOFFCNFG2_WD_RST_WK, MAX77620_ONOFFCNFG2_WD_RST_WK); if (ret < 0) { dev_err(wdt->dev, "Failed to set WD_RST_WK: %d\n", ret); return ret; } /* Set WDT clear in OFF and sleep mode */ ret = regmap_update_bits(wdt->rmap, MAX77620_REG_CNFGGLBL2, MAX77620_WDTOFFC | MAX77620_WDTSLPC, MAX77620_WDTOFFC | MAX77620_WDTSLPC); if (ret < 0) { dev_err(wdt->dev, "Failed to set WDT OFF mode: %d\n", ret); return ret; } /* Check if WDT running and if yes then set flags properly */ ret = regmap_read(wdt->rmap, MAX77620_REG_CNFGGLBL2, ®val); if (ret < 0) { dev_err(wdt->dev, "Failed to read WDT CFG register: %d\n", ret); return ret; } switch (regval & MAX77620_TWD_MASK) { case MAX77620_TWD_2s: wdt_dev->timeout = 2; break; case MAX77620_TWD_16s: wdt_dev->timeout = 16; break; case MAX77620_TWD_64s: wdt_dev->timeout = 64; break; default: wdt_dev->timeout = 128; break; } if (regval & MAX77620_WDTEN) set_bit(WDOG_HW_RUNNING, &wdt_dev->status); watchdog_set_nowayout(wdt_dev, nowayout); watchdog_set_drvdata(wdt_dev, wdt); ret = watchdog_register_device(wdt_dev); if (ret < 0) { dev_err(&pdev->dev, "watchdog registration failed: %d\n", ret); return ret; } return 0; } static int max77620_wdt_remove(struct platform_device *pdev) { struct max77620_wdt *wdt = platform_get_drvdata(pdev); max77620_wdt_stop(&wdt->wdt_dev); watchdog_unregister_device(&wdt->wdt_dev); return 0; } static struct platform_device_id max77620_wdt_devtype[] = { { .name = "max77620-watchdog", }, { }, }; MODULE_DEVICE_TABLE(platform, max77620_wdt_devtype); static struct platform_driver max77620_wdt_driver = { .driver = { .name = "max77620-watchdog", }, .probe = max77620_wdt_probe, .remove = max77620_wdt_remove, .id_table = max77620_wdt_devtype, }; module_platform_driver(max77620_wdt_driver); MODULE_DESCRIPTION("Max77620 watchdog timer driver"); module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); MODULE_AUTHOR("Laxman Dewangan "); MODULE_LICENSE("GPL v2"); mp;id2=bf29bddf0417a4783da3b24e8c9e017ac649326f'>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 'net/mac80211')