From patchwork Fri Aug 19 22:17:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Guilherme G. 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Piccoli" To: akpm@linux-foundation.org, bhe@redhat.com, pmladek@suse.com, kexec@lists.infradead.org Cc: linux-kernel@vger.kernel.org, linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, x86@kernel.org, kernel-dev@igalia.com, kernel@gpiccoli.net, halves@canonical.com, fabiomirmar@gmail.com, alejandro.j.jimenez@oracle.com, andriy.shevchenko@linux.intel.com, arnd@arndb.de, bp@alien8.de, corbet@lwn.net, d.hatayama@jp.fujitsu.com, dave.hansen@linux.intel.com, dyoung@redhat.com, feng.tang@intel.com, gregkh@linuxfoundation.org, mikelley@microsoft.com, hidehiro.kawai.ez@hitachi.com, jgross@suse.com, john.ogness@linutronix.de, keescook@chromium.org, luto@kernel.org, mhiramat@kernel.org, mingo@redhat.com, paulmck@kernel.org, peterz@infradead.org, rostedt@goodmis.org, senozhatsky@chromium.org, stern@rowland.harvard.edu, tglx@linutronix.de, vgoyal@redhat.com, vkuznets@redhat.com, will@kernel.org, xuqiang36@huawei.com, "Guilherme G. Piccoli" , linux-edac@vger.kernel.org, Tony Luck , Dinh Nguyen Subject: [PATCH V3 08/11] EDAC/altera: Skip the panic notifier if kdump is loaded Date: Fri, 19 Aug 2022 19:17:28 -0300 Message-Id: <20220819221731.480795-9-gpiccoli@igalia.com> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220819221731.480795-1-gpiccoli@igalia.com> References: <20220819221731.480795-1-gpiccoli@igalia.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-edac@vger.kernel.org The altera_edac panic notifier performs some data collection with regards errors detected; such code relies in the regmap layer to perform reads/writes, so the code is abstracted and there is some risk level to execute that, since the panic path runs in atomic context, with interrupts/preemption and secondary CPUs disabled. Users want the information collected in this panic notifier though, so in order to balance the risk/benefit, let's skip the altera panic notifier if kdump is loaded. While at it, remove a useless header and encompass a macro inside the sole ifdef block it is used. Cc: Borislav Petkov Cc: Petr Mladek Cc: Tony Luck Acked-by: Dinh Nguyen Signed-off-by: Guilherme G. Piccoli --- V3: - added the ack tag from Dinh - thanks! - had a good discussion with Boris about that in V2 [0], hopefully we can continue and reach a consensus in this V3. [0] https://lore.kernel.org/lkml/46137c67-25b4-6657-33b7-cffdc7afc0d7@igalia.com/ V2: - new patch, based on the discussion in [1]. [1] https://lore.kernel.org/lkml/62a63fc2-346f-f375-043a-fa21385279df@igalia.com/ drivers/edac/altera_edac.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c index e7e8e624a436..741fe5539154 100644 --- a/drivers/edac/altera_edac.c +++ b/drivers/edac/altera_edac.c @@ -16,7 +16,6 @@ #include #include #include -#include #include #include #include @@ -24,6 +23,7 @@ #include #include #include +#include #include #include "altera_edac.h" @@ -2063,22 +2063,30 @@ static const struct irq_domain_ops a10_eccmgr_ic_ops = { }; /************** Stratix 10 EDAC Double Bit Error Handler ************/ -#define to_a10edac(p, m) container_of(p, struct altr_arria10_edac, m) - #ifdef CONFIG_64BIT /* panic routine issues reboot on non-zero panic_timeout */ extern int panic_timeout; +#define to_a10edac(p, m) container_of(p, struct altr_arria10_edac, m) + /* * The double bit error is handled through SError which is fatal. This is * called as a panic notifier to printout ECC error info as part of the panic. + * + * Notice that if kdump is set, we take the risk avoidance approach and + * skip the notifier, given that users are expected to have access to a + * full vmcore. */ static int s10_edac_dberr_handler(struct notifier_block *this, unsigned long event, void *ptr) { - struct altr_arria10_edac *edac = to_a10edac(this, panic_notifier); + struct altr_arria10_edac *edac; int err_addr, dberror; + if (kexec_crash_loaded()) + return NOTIFY_DONE; + + edac = to_a10edac(this, panic_notifier); regmap_read(edac->ecc_mgr_map, S10_SYSMGR_ECC_INTSTAT_DERR_OFST, &dberror); regmap_write(edac->ecc_mgr_map, S10_SYSMGR_UE_VAL_OFST, dberror);