From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5B3FE156F7; Tue, 15 Aug 2023 19:07:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1F710C433C7; Tue, 15 Aug 2023 19:07:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692126427; bh=MJRTsKjJrCqgZBHh3ucJktBplP659QkvtPqpYoiAoQY=; h=From:Date:Subject:To:Cc:From; b=e5wIKX0EVRDwQ8ztXhcobA5K0H7FetEp9rCkWJCAkGOuVzNaswxxaDMkJDz/5BLUY p3U2fSmikJ/+yYR6zf1Q6hSqg9Na159AiTm9D8+F4NfGfrNd/fjsWuAfUamHcAgdtD 040pJTC/tEnDHObPF0x37dC+WZgYZmbgstlFKPwIN/q7/aHumtMsf+/j8tSZ85dkCS +NDmXcKdcGPYoy51TznvaaItdBvpwDhBP8NWjDoRDZCugP3GKy1OUGc8dU4bGVv0DP gaI5fSECd5w3krOG+Uy6QDTpYLf8MbfR8f5RuopIr4q7asAcbHuBxAoViW2z1WJryr seDIlPdcvkBmg== From: Nathan Chancellor Date: Tue, 15 Aug 2023 12:06:50 -0700 Subject: [PATCH] watchdog: xilinx_wwdt: Use div_u64() in xilinx_wwdt_start() Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20230815-watchdog-xilinx-div_u64-v1-1-20b0b5a65c2e@kernel.org> X-B4-Tracking: v=1; b=H4sIAMnM22QC/x3MywqAIBBA0V+JWTdglr1+JSJCpxoIC+0hRP+et DyLex/w5Jg8tMkDji72vNmILE1AL6OdCdlEgxQyF3Wm8B4PvZhtxsAr24CGr+EsC6yVlpUulSi aHGK9O5o4/Oeuf98PnGt1FGkAAAA= To: srinivas.neeli@amd.com, wim@linux-watchdog.org Cc: shubhrajyoti.datta@amd.com, michal.simek@amd.com, linux@roeck-us.net, ndesaulniers@google.com, trix@redhat.com, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, patches@lists.linux.dev, llvm@lists.linux.dev, Nathan Chancellor X-Mailer: b4 0.13-dev X-Developer-Signature: v=1; a=openpgp-sha256; l=1840; i=nathan@kernel.org; h=from:subject:message-id; bh=MJRTsKjJrCqgZBHh3ucJktBplP659QkvtPqpYoiAoQY=; b=owGbwMvMwCEmm602sfCA1DTG02pJDCm3z9za46s+3+aG7cQa/fs105dt+eAvter+059nAv7Xp og5zpNt7ShlYRDjYJAVU2Spfqx63NBwzlnGG6cmwcxhZQIZwsDFKQAT2bmUkaHTbNGCHMVL139w r5namNxs7dgxv8peou6PmCW32LuiSy0M/+uEYhQn/lDSj7JOLxBh8zn4u3xJ2Y5qx4bjS/lvGTh PZQQA X-Developer-Key: i=nathan@kernel.org; a=openpgp; fpr=2437CB76E544CB6AB3D9DFD399739260CB6CB716 After commit f1a43aadb5a6 ("watchdog: Enable COMPILE_TEST for more drivers"), it is possible to enable this driver on 32-bit architectures. When building for those architectures with clang, there is an error due to a 64-bit division in xilinx_wwdt_start(): ERROR: modpost: "__aeabi_uldivmod" [drivers/watchdog/xilinx_wwdt.ko] undefined! Use div_u64() to fix this, which takes a 64-bit dividend and 32-bit divisor. GCC likely avoids the same error due to optimizations it employs to transform division by a constant into other equivalent operations, which may be different than what is implemented in clang. Link: https://github.com/ClangBuiltLinux/linux/issues/1915 Signed-off-by: Nathan Chancellor --- drivers/watchdog/xilinx_wwdt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/watchdog/xilinx_wwdt.c b/drivers/watchdog/xilinx_wwdt.c index 1d998db41533..d271e2e8d6e2 100644 --- a/drivers/watchdog/xilinx_wwdt.c +++ b/drivers/watchdog/xilinx_wwdt.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -71,7 +72,7 @@ static int xilinx_wwdt_start(struct watchdog_device *wdd) /* Calculate timeout count */ time_out = xdev->freq * wdd->timeout; - closed_timeout = (time_out * xdev->close_percent) / 100; + closed_timeout = div_u64(time_out * xdev->close_percent, 100); open_timeout = time_out - closed_timeout; wdd->min_hw_heartbeat_ms = xdev->close_percent * 10 * wdd->timeout; --- base-commit: 8a504bd61ec7b3ddd72680e15775f2c7c0f9e894 change-id: 20230815-watchdog-xilinx-div_u64-85c27c650493 Best regards, -- Nathan Chancellor