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![Andy Shevchenko](/assets/img/avatar_default.png)
When SCU is not ready and CONFIG_DEBUG_SHIRQ=y we got deferred probe followed
by fired test IRQ which immediately makes kernel panic. Fix this by delaying
IRQ handler registration till SCU is ready.
Fixes: 80ae679b8f
("watchdog: intel-mid_wdt: Convert to use new SCU IPC API")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
205 lines
4.9 KiB
C
205 lines
4.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* intel-mid_wdt: generic Intel MID SCU watchdog driver
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*
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* Platforms supported so far:
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* - Merrifield only
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*
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* Copyright (C) 2014 Intel Corporation. All rights reserved.
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* Contact: David Cohen <david.a.cohen@linux.intel.com>
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*/
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#include <linux/interrupt.h>
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#include <linux/module.h>
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#include <linux/nmi.h>
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#include <linux/platform_device.h>
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#include <linux/watchdog.h>
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#include <linux/platform_data/intel-mid_wdt.h>
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#include <asm/intel_scu_ipc.h>
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#include <asm/intel-mid.h>
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#define IPC_WATCHDOG 0xf8
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#define MID_WDT_PRETIMEOUT 15
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#define MID_WDT_TIMEOUT_MIN (1 + MID_WDT_PRETIMEOUT)
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#define MID_WDT_TIMEOUT_MAX 170
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#define MID_WDT_DEFAULT_TIMEOUT 90
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/* SCU watchdog messages */
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enum {
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SCU_WATCHDOG_START = 0,
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SCU_WATCHDOG_STOP,
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SCU_WATCHDOG_KEEPALIVE,
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};
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struct mid_wdt {
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struct watchdog_device wd;
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struct device *dev;
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struct intel_scu_ipc_dev *scu;
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};
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static inline int
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wdt_command(struct mid_wdt *mid, int sub, const void *in, size_t inlen, size_t size)
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{
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struct intel_scu_ipc_dev *scu = mid->scu;
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return intel_scu_ipc_dev_command_with_size(scu, IPC_WATCHDOG, sub, in,
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inlen, size, NULL, 0);
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}
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static int wdt_start(struct watchdog_device *wd)
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{
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struct mid_wdt *mid = watchdog_get_drvdata(wd);
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int ret, in_size;
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int timeout = wd->timeout;
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struct ipc_wd_start {
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u32 pretimeout;
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u32 timeout;
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} ipc_wd_start = { timeout - MID_WDT_PRETIMEOUT, timeout };
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/*
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* SCU expects the input size for watchdog IPC to be 2 which is the
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* size of the structure in dwords. SCU IPC normally takes bytes
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* but this is a special case where we specify size to be different
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* than inlen.
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*/
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in_size = DIV_ROUND_UP(sizeof(ipc_wd_start), 4);
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ret = wdt_command(mid, SCU_WATCHDOG_START, &ipc_wd_start,
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sizeof(ipc_wd_start), in_size);
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if (ret)
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dev_crit(mid->dev, "error starting watchdog: %d\n", ret);
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return ret;
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}
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static int wdt_ping(struct watchdog_device *wd)
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{
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struct mid_wdt *mid = watchdog_get_drvdata(wd);
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int ret;
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ret = wdt_command(mid, SCU_WATCHDOG_KEEPALIVE, NULL, 0, 0);
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if (ret)
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dev_crit(mid->dev, "Error executing keepalive: %d\n", ret);
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return ret;
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}
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static int wdt_stop(struct watchdog_device *wd)
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{
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struct mid_wdt *mid = watchdog_get_drvdata(wd);
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int ret;
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ret = wdt_command(mid, SCU_WATCHDOG_STOP, NULL, 0, 0);
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if (ret)
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dev_crit(mid->dev, "Error stopping watchdog: %d\n", ret);
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return ret;
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}
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static irqreturn_t mid_wdt_irq(int irq, void *dev_id)
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{
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panic("Kernel Watchdog");
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/* This code should not be reached */
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return IRQ_HANDLED;
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}
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static const struct watchdog_info mid_wdt_info = {
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.identity = "Intel MID SCU watchdog",
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.options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE,
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};
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static const struct watchdog_ops mid_wdt_ops = {
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.owner = THIS_MODULE,
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.start = wdt_start,
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.stop = wdt_stop,
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.ping = wdt_ping,
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};
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static int mid_wdt_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct watchdog_device *wdt_dev;
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struct intel_mid_wdt_pdata *pdata = dev->platform_data;
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struct mid_wdt *mid;
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int ret;
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if (!pdata) {
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dev_err(dev, "missing platform data\n");
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return -EINVAL;
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}
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if (pdata->probe) {
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ret = pdata->probe(pdev);
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if (ret)
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return ret;
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}
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mid = devm_kzalloc(dev, sizeof(*mid), GFP_KERNEL);
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if (!mid)
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return -ENOMEM;
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mid->dev = dev;
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wdt_dev = &mid->wd;
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wdt_dev->info = &mid_wdt_info;
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wdt_dev->ops = &mid_wdt_ops;
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wdt_dev->min_timeout = MID_WDT_TIMEOUT_MIN;
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wdt_dev->max_timeout = MID_WDT_TIMEOUT_MAX;
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wdt_dev->timeout = MID_WDT_DEFAULT_TIMEOUT;
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wdt_dev->parent = dev;
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watchdog_set_nowayout(wdt_dev, WATCHDOG_NOWAYOUT);
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watchdog_set_drvdata(wdt_dev, mid);
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mid->scu = devm_intel_scu_ipc_dev_get(dev);
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if (!mid->scu)
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return -EPROBE_DEFER;
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ret = devm_request_irq(dev, pdata->irq, mid_wdt_irq,
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IRQF_SHARED | IRQF_NO_SUSPEND, "watchdog",
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wdt_dev);
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if (ret) {
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dev_err(dev, "error requesting warning irq %d\n", pdata->irq);
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return ret;
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}
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/*
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* The firmware followed by U-Boot leaves the watchdog running
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* with the default threshold which may vary. When we get here
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* we should make a decision to prevent any side effects before
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* user space daemon will take care of it. The best option,
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* taking into consideration that there is no way to read values
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* back from hardware, is to enforce watchdog being run with
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* deterministic values.
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*/
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ret = wdt_start(wdt_dev);
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if (ret)
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return ret;
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/* Make sure the watchdog is serviced */
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set_bit(WDOG_HW_RUNNING, &wdt_dev->status);
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ret = devm_watchdog_register_device(dev, wdt_dev);
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if (ret)
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return ret;
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dev_info(dev, "Intel MID watchdog device probed\n");
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return 0;
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}
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static struct platform_driver mid_wdt_driver = {
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.probe = mid_wdt_probe,
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.driver = {
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.name = "intel_mid_wdt",
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},
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};
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module_platform_driver(mid_wdt_driver);
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MODULE_AUTHOR("David Cohen <david.a.cohen@linux.intel.com>");
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MODULE_DESCRIPTION("Watchdog Driver for Intel MID platform");
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MODULE_LICENSE("GPL");
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