From mboxrd@z Thu Jan 1 00:00:00 1970 From: Doug Berger Subject: [PATCH v2 7/8] bus: brcmstb_gisb: add notifier handling Date: Tue, 28 Mar 2017 14:34:30 -0700 Message-ID: <20170328213431.10904-8-opendmb@gmail.com> References: <20170328213431.10904-1-opendmb@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20170328213431.10904-1-opendmb@gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: mark.rutland@arm.com Cc: wangkefeng.wang@huawei.com, catalin.marinas@arm.com, linus.walleij@linaro.org, will.deacon@arm.com, mingo@kernel.org, f.fainelli@gmail.com, jonathanh@nvidia.com, bgolaszewski@baylibre.com, bcm-kernel-feedback-list@broadcom.com, shijie.huang@arm.com, opendmb@gmail.com, treding@nvidia.com, devicetree@vger.kernel.org, suzuki.poulose@arm.com, robh+dt@kernel.org, gregory.0xf0@gmail.com, sandeepa.s.prabhu@gmail.com, linux-arm-kernel@lists.infradead.org, mirza.krak@gmail.com, linux-kernel@vger.kernel.org, james.morse@arm.com, olof@lixom.net, computersforpeace@gmail.com List-Id: devicetree@vger.kernel.org Check for GISB arbitration errors through a chained notifier when a process dies or a kernel panic occurs. This allows a meaningful diagnostic message to occur along with other diagnostic information. Notably writes to a bad GISB address on an ARM64 architecture kernel cause unrecoverable SError aborts and this allows the cause of the abort to be seen. Signed-off-by: Doug Berger --- drivers/bus/brcmstb_gisb.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) diff --git a/drivers/bus/brcmstb_gisb.c b/drivers/bus/brcmstb_gisb.c index 500b6bb5c739..774729002b8c 100644 --- a/drivers/bus/brcmstb_gisb.c +++ b/drivers/bus/brcmstb_gisb.c @@ -24,6 +24,8 @@ #include #include #include +#include +#include #ifdef CONFIG_ARM #include @@ -290,6 +292,25 @@ static irqreturn_t brcmstb_gisb_tea_handler(int irq, void *dev_id) return IRQ_HANDLED; } +/* + * Dump out gisb errors on die or panic. + */ +static int dump_gisb_error(struct notifier_block *self, unsigned long v, + void *p) +{ + struct brcmstb_gisb_arb_device *gdev; + + /* iterate over each GISB arb registered handlers */ + list_for_each_entry(gdev, &brcmstb_gisb_arb_device_list, next) + brcmstb_gisb_arb_decode_addr(gdev, "async abort"); + + return 0; +} + +static struct notifier_block gisb_error_notifier = { + .notifier_call = dump_gisb_error, +}; + static DEVICE_ATTR(gisb_arb_timeout, S_IWUSR | S_IRUGO, gisb_arb_get_timeout, gisb_arb_set_timeout); @@ -408,6 +429,12 @@ static int __init brcmstb_gisb_arb_probe(struct platform_device *pdev) board_be_handler = brcmstb_bus_error_handler; #endif + if (list_is_singular(&brcmstb_gisb_arb_device_list)) { + register_die_notifier(&gisb_error_notifier); + atomic_notifier_chain_register(&panic_notifier_list, + &gisb_error_notifier); + } + dev_info(&pdev->dev, "registered mem: %p, irqs: %d, %d\n", gdev->base, timeout_irq, tea_irq); -- 2.12.0