From: Harini T <harini.t@amd.com> To: <linux@roeck-us.net>, <michal.simek@amd.com>, <srinivas.neeli@amd.com>, <shubhrajyoti.datta@amd.com> Cc: <srinivas.goud@amd.com>, <wim@linux-watchdog.org>, <linux-watchdog@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>, <git@amd.com>, Harini T <harini.t@amd.com> Subject: [PATCH] watchdog: xilinx_wwdt: Add check for timeout limit and set maximum value if exceeded Date: Tue, 19 Mar 2024 16:42:19 +0530 [thread overview] Message-ID: <20240319111219.21094-1-harini.t@amd.com> (raw) Current implementation fails to verify if the user input such as timeout or closed window percentage exceeds the maximum value that the hardware supports. Maximum timeout is derived based on input clock frequency. If the user input timeout exceeds the maximum timeout supported, limit the timeout to maximum supported value. Limit the close and open window percent to hardware supported value. Signed-off-by: Harini T <harini.t@amd.com> --- drivers/watchdog/xilinx_wwdt.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/xilinx_wwdt.c b/drivers/watchdog/xilinx_wwdt.c index d271e2e8d6e2..86e2edc4f3c7 100644 --- a/drivers/watchdog/xilinx_wwdt.c +++ b/drivers/watchdog/xilinx_wwdt.c @@ -36,6 +36,12 @@ #define XWWDT_CLOSE_WINDOW_PERCENT 50 +/* Maximum count value of each 32 bit window */ +#define XWWDT_MAX_COUNT_WINDOW GENMASK(31, 0) + +/* Maximum count value of closed and open window combined*/ +#define XWWDT_MAX_COUNT_WINDOW_COMBINED GENMASK_ULL(32, 1) + static int wwdt_timeout; static int closed_window_percent; @@ -73,6 +79,24 @@ static int xilinx_wwdt_start(struct watchdog_device *wdd) /* Calculate timeout count */ time_out = xdev->freq * wdd->timeout; closed_timeout = div_u64(time_out * xdev->close_percent, 100); + + if (time_out > XWWDT_MAX_COUNT_WINDOW) { + u64 min_close_timeout = time_out - XWWDT_MAX_COUNT_WINDOW; + u64 max_close_timeout = XWWDT_MAX_COUNT_WINDOW; + + if (closed_timeout > max_close_timeout) { + dev_info(xilinx_wwdt_wdd->parent, + "Closed window cannot be set to %d%%. Using maximum supported value.\n", + xdev->close_percent); + closed_timeout = max_close_timeout; + } else if (closed_timeout < min_close_timeout) { + dev_info(xilinx_wwdt_wdd->parent, + "Closed window cannot be set to %d%%. Using minimum supported value.\n", + xdev->close_percent); + closed_timeout = min_close_timeout; + } + } + open_timeout = time_out - closed_timeout; wdd->min_hw_heartbeat_ms = xdev->close_percent * 10 * wdd->timeout; @@ -132,6 +156,7 @@ static int xwwdt_probe(struct platform_device *pdev) { struct watchdog_device *xilinx_wwdt_wdd; struct device *dev = &pdev->dev; + unsigned int max_hw_heartbeat; struct xwwdt_device *xdev; struct clk *clk; int ret; @@ -157,9 +182,11 @@ static int xwwdt_probe(struct platform_device *pdev) if (!xdev->freq) return -EINVAL; + max_hw_heartbeat = div64_u64(XWWDT_MAX_COUNT_WINDOW_COMBINED, xdev->freq); + xilinx_wwdt_wdd->min_timeout = XWWDT_MIN_TIMEOUT; xilinx_wwdt_wdd->timeout = XWWDT_DEFAULT_TIMEOUT; - xilinx_wwdt_wdd->max_hw_heartbeat_ms = 1000 * xilinx_wwdt_wdd->timeout; + xilinx_wwdt_wdd->max_hw_heartbeat_ms = 1000 * max_hw_heartbeat; if (closed_window_percent == 0 || closed_window_percent >= 100) xdev->close_percent = XWWDT_CLOSE_WINDOW_PERCENT; @@ -167,6 +194,7 @@ static int xwwdt_probe(struct platform_device *pdev) xdev->close_percent = closed_window_percent; watchdog_init_timeout(xilinx_wwdt_wdd, wwdt_timeout, &pdev->dev); + xilinx_wwdt_wdd->timeout = min_not_zero(xilinx_wwdt_wdd->timeout, max_hw_heartbeat); spin_lock_init(&xdev->spinlock); watchdog_set_drvdata(xilinx_wwdt_wdd, xdev); watchdog_set_nowayout(xilinx_wwdt_wdd, 1); -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Harini T <harini.t@amd.com> To: <linux@roeck-us.net>, <michal.simek@amd.com>, <srinivas.neeli@amd.com>, <shubhrajyoti.datta@amd.com> Cc: <srinivas.goud@amd.com>, <wim@linux-watchdog.org>, <linux-watchdog@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>, <git@amd.com>, Harini T <harini.t@amd.com> Subject: [PATCH] watchdog: xilinx_wwdt: Add check for timeout limit and set maximum value if exceeded Date: Tue, 19 Mar 2024 16:42:19 +0530 [thread overview] Message-ID: <20240319111219.21094-1-harini.t@amd.com> (raw) Current implementation fails to verify if the user input such as timeout or closed window percentage exceeds the maximum value that the hardware supports. Maximum timeout is derived based on input clock frequency. If the user input timeout exceeds the maximum timeout supported, limit the timeout to maximum supported value. Limit the close and open window percent to hardware supported value. Signed-off-by: Harini T <harini.t@amd.com> --- drivers/watchdog/xilinx_wwdt.c | 30 +++++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/xilinx_wwdt.c b/drivers/watchdog/xilinx_wwdt.c index d271e2e8d6e2..86e2edc4f3c7 100644 --- a/drivers/watchdog/xilinx_wwdt.c +++ b/drivers/watchdog/xilinx_wwdt.c @@ -36,6 +36,12 @@ #define XWWDT_CLOSE_WINDOW_PERCENT 50 +/* Maximum count value of each 32 bit window */ +#define XWWDT_MAX_COUNT_WINDOW GENMASK(31, 0) + +/* Maximum count value of closed and open window combined*/ +#define XWWDT_MAX_COUNT_WINDOW_COMBINED GENMASK_ULL(32, 1) + static int wwdt_timeout; static int closed_window_percent; @@ -73,6 +79,24 @@ static int xilinx_wwdt_start(struct watchdog_device *wdd) /* Calculate timeout count */ time_out = xdev->freq * wdd->timeout; closed_timeout = div_u64(time_out * xdev->close_percent, 100); + + if (time_out > XWWDT_MAX_COUNT_WINDOW) { + u64 min_close_timeout = time_out - XWWDT_MAX_COUNT_WINDOW; + u64 max_close_timeout = XWWDT_MAX_COUNT_WINDOW; + + if (closed_timeout > max_close_timeout) { + dev_info(xilinx_wwdt_wdd->parent, + "Closed window cannot be set to %d%%. Using maximum supported value.\n", + xdev->close_percent); + closed_timeout = max_close_timeout; + } else if (closed_timeout < min_close_timeout) { + dev_info(xilinx_wwdt_wdd->parent, + "Closed window cannot be set to %d%%. Using minimum supported value.\n", + xdev->close_percent); + closed_timeout = min_close_timeout; + } + } + open_timeout = time_out - closed_timeout; wdd->min_hw_heartbeat_ms = xdev->close_percent * 10 * wdd->timeout; @@ -132,6 +156,7 @@ static int xwwdt_probe(struct platform_device *pdev) { struct watchdog_device *xilinx_wwdt_wdd; struct device *dev = &pdev->dev; + unsigned int max_hw_heartbeat; struct xwwdt_device *xdev; struct clk *clk; int ret; @@ -157,9 +182,11 @@ static int xwwdt_probe(struct platform_device *pdev) if (!xdev->freq) return -EINVAL; + max_hw_heartbeat = div64_u64(XWWDT_MAX_COUNT_WINDOW_COMBINED, xdev->freq); + xilinx_wwdt_wdd->min_timeout = XWWDT_MIN_TIMEOUT; xilinx_wwdt_wdd->timeout = XWWDT_DEFAULT_TIMEOUT; - xilinx_wwdt_wdd->max_hw_heartbeat_ms = 1000 * xilinx_wwdt_wdd->timeout; + xilinx_wwdt_wdd->max_hw_heartbeat_ms = 1000 * max_hw_heartbeat; if (closed_window_percent == 0 || closed_window_percent >= 100) xdev->close_percent = XWWDT_CLOSE_WINDOW_PERCENT; @@ -167,6 +194,7 @@ static int xwwdt_probe(struct platform_device *pdev) xdev->close_percent = closed_window_percent; watchdog_init_timeout(xilinx_wwdt_wdd, wwdt_timeout, &pdev->dev); + xilinx_wwdt_wdd->timeout = min_not_zero(xilinx_wwdt_wdd->timeout, max_hw_heartbeat); spin_lock_init(&xdev->spinlock); watchdog_set_drvdata(xilinx_wwdt_wdd, xdev); watchdog_set_nowayout(xilinx_wwdt_wdd, 1); -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2024-03-19 11:12 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-03-19 11:12 Harini T [this message] 2024-03-19 11:12 ` [PATCH] watchdog: xilinx_wwdt: Add check for timeout limit and set maximum value if exceeded Harini T 2024-03-19 14:07 ` Guenter Roeck 2024-03-19 14:07 ` Guenter Roeck 2024-05-08 15:17 ` T, Harini 2024-05-08 15:17 ` T, Harini
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