From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 874D5C432C3 for ; Fri, 22 Nov 2019 06:05:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5E7E22068F for ; Fri, 22 Nov 2019 06:05:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402745; bh=IRIFf4jSVFyly0lxBpHg7bfrDIjAbhsrihdGmuphs/k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ajcjuPDAczeiTDOPTzJJM0ZSZ8PQzaLb3aPmigBbm6S/vvRL0EQLMDPGRk24x/Ren pt8/j5DIYwRA9E/+AmuLBpDnkoCGWoshFHaxXGr7cwynf+YLbh/oP9mulgFYOTc026 E1oiCy+ST8TLVeKRo7pJ7ovAcZj5V8cZKtgGgEhA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729026AbfKVGFo (ORCPT ); Fri, 22 Nov 2019 01:05:44 -0500 Received: from mail.kernel.org ([198.145.29.99]:41276 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729739AbfKVGCc (ORCPT ); Fri, 22 Nov 2019 01:02:32 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 4D7672071B; Fri, 22 Nov 2019 06:02:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574402552; bh=IRIFf4jSVFyly0lxBpHg7bfrDIjAbhsrihdGmuphs/k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HBLrEUyHydnB2kD6kJ3cwZSIQR3Fp+4YhwN0eLps7c6VMqR72//2Gu78HYtf6S0Pu y9iAUWkHIKLobDgp42vxbRCY23AC8NEfjU/aswiF0hJYWCPDpPV8stLxxXhreynm0v PVLlP+K5qf0KNQGQ6dsxZp48e3LrKv7EQGV8xic0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Christophe Leroy , Scott Wood , Sasha Levin , linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 4.9 57/91] powerpc/83xx: handle machine check caused by watchdog timer Date: Fri, 22 Nov 2019 01:00:55 -0500 Message-Id: <20191122060129.4239-56-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122060129.4239-1-sashal@kernel.org> References: <20191122060129.4239-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Christophe Leroy [ Upstream commit 0deae39cec6dab3a66794f3e9e83ca4dc30080f1 ] When the watchdog timer is set in interrupt mode, it causes a machine check when it times out. The purpose of this mode is to ease debugging, not to crash the kernel and reboot the machine. This patch implements a special handling for that, in order to not crash the kernel if the watchdog times out while in interrupt or within the idle task. Signed-off-by: Christophe Leroy [scottwood: added missing #include] Signed-off-by: Scott Wood Signed-off-by: Sasha Levin --- arch/powerpc/include/asm/cputable.h | 1 + arch/powerpc/include/asm/reg.h | 2 ++ arch/powerpc/kernel/cputable.c | 10 ++++++---- arch/powerpc/platforms/83xx/misc.c | 17 +++++++++++++++++ 4 files changed, 26 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h index 4e54282c29b44..cf51aea47510c 100644 --- a/arch/powerpc/include/asm/cputable.h +++ b/arch/powerpc/include/asm/cputable.h @@ -44,6 +44,7 @@ extern int machine_check_e500(struct pt_regs *regs); extern int machine_check_e200(struct pt_regs *regs); extern int machine_check_47x(struct pt_regs *regs); int machine_check_8xx(struct pt_regs *regs); +int machine_check_83xx(struct pt_regs *regs); extern void cpu_down_flush_e500v2(void); extern void cpu_down_flush_e500mc(void); diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h index ceb168cd3b814..26aeeaad32678 100644 --- a/arch/powerpc/include/asm/reg.h +++ b/arch/powerpc/include/asm/reg.h @@ -663,6 +663,8 @@ #define SRR1_PROGTRAP 0x00020000 /* Trap */ #define SRR1_PROGADDR 0x00010000 /* SRR0 contains subsequent addr */ +#define SRR1_MCE_MCP 0x00080000 /* Machine check signal caused interrupt */ + #define SPRN_HSRR0 0x13A /* Save/Restore Register 0 */ #define SPRN_HSRR1 0x13B /* Save/Restore Register 1 */ #define HSRR1_DENORM 0x00100000 /* Denorm exception */ diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c index 6a82ef039c509..7471ed48f41fa 100644 --- a/arch/powerpc/kernel/cputable.c +++ b/arch/powerpc/kernel/cputable.c @@ -1162,6 +1162,7 @@ static struct cpu_spec __initdata cpu_specs[] = { .machine_check = machine_check_generic, .platform = "ppc603", }, +#ifdef CONFIG_PPC_83xx { /* e300c1 (a 603e core, plus some) on 83xx */ .pvr_mask = 0x7fff0000, .pvr_value = 0x00830000, @@ -1172,7 +1173,7 @@ static struct cpu_spec __initdata cpu_specs[] = { .icache_bsize = 32, .dcache_bsize = 32, .cpu_setup = __setup_cpu_603, - .machine_check = machine_check_generic, + .machine_check = machine_check_83xx, .platform = "ppc603", }, { /* e300c2 (an e300c1 core, plus some, minus FPU) on 83xx */ @@ -1186,7 +1187,7 @@ static struct cpu_spec __initdata cpu_specs[] = { .icache_bsize = 32, .dcache_bsize = 32, .cpu_setup = __setup_cpu_603, - .machine_check = machine_check_generic, + .machine_check = machine_check_83xx, .platform = "ppc603", }, { /* e300c3 (e300c1, plus one IU, half cache size) on 83xx */ @@ -1200,7 +1201,7 @@ static struct cpu_spec __initdata cpu_specs[] = { .icache_bsize = 32, .dcache_bsize = 32, .cpu_setup = __setup_cpu_603, - .machine_check = machine_check_generic, + .machine_check = machine_check_83xx, .num_pmcs = 4, .oprofile_cpu_type = "ppc/e300", .oprofile_type = PPC_OPROFILE_FSL_EMB, @@ -1217,12 +1218,13 @@ static struct cpu_spec __initdata cpu_specs[] = { .icache_bsize = 32, .dcache_bsize = 32, .cpu_setup = __setup_cpu_603, - .machine_check = machine_check_generic, + .machine_check = machine_check_83xx, .num_pmcs = 4, .oprofile_cpu_type = "ppc/e300", .oprofile_type = PPC_OPROFILE_FSL_EMB, .platform = "ppc603", }, +#endif { /* default match, we assume split I/D cache & TB (non-601)... */ .pvr_mask = 0x00000000, .pvr_value = 0x00000000, diff --git a/arch/powerpc/platforms/83xx/misc.c b/arch/powerpc/platforms/83xx/misc.c index d75c9816a5c92..2b6589fe812dd 100644 --- a/arch/powerpc/platforms/83xx/misc.c +++ b/arch/powerpc/platforms/83xx/misc.c @@ -14,6 +14,7 @@ #include #include +#include #include #include #include @@ -150,3 +151,19 @@ void __init mpc83xx_setup_arch(void) mpc83xx_setup_pci(); } + +int machine_check_83xx(struct pt_regs *regs) +{ + u32 mask = 1 << (31 - IPIC_MCP_WDT); + + if (!(regs->msr & SRR1_MCE_MCP) || !(ipic_get_mcp_status() & mask)) + return machine_check_generic(regs); + ipic_clear_mcp_status(mask); + + if (debugger_fault_handler(regs)) + return 1; + + die("Watchdog NMI Reset", regs, 0); + + return 1; +} -- 2.20.1