From abf051be684be768c1ee079514f4d07de9389d54 Mon Sep 17 00:00:00 2001 From: Vaibhav Jain Date: Wed, 16 Nov 2016 19:39:33 +0530 Subject: [PATCH] cxl: Do adapter fence check before handling afu interrupt If an afu interrupt is in flight when an eeh error is triggered the control still reaches the function native_irq_multiplexed and the PE-Handle read from the CXL_PSL_PEHandle_An register is 0xffff. The function then erroneously assumes that the interrupt belonged to a detached context and generates a warning with full stack dump in the kernel log complaining: "Unable to demultiplex CXL PSL IRQ for PE 65535 DSISR ffffffff DAR ffffffff. (Possible AFU HW issue - was a term/remove acked with outstanding transactions" To fix this the patch adds new code to the function native_irq_multiplexed function to compares the read value of register CXL_PSL_PEHandle_An to ~0ULL. If true then logs a warning message saying that the interrupt is being ignored and returns IRQ_HANDLED from the irq handler. Reviewed-by: Andrew Donnellan Acked-by: Frederic Barrat Acked-by: Ian Munsie Signed-off-by: Vaibhav Jain Signed-off-by: Michael Ellerman --- drivers/misc/cxl/native.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c index a217a74ccc98..c336350ede94 100644 --- a/drivers/misc/cxl/native.c +++ b/drivers/misc/cxl/native.c @@ -931,9 +931,18 @@ static irqreturn_t native_irq_multiplexed(int irq, void *data) struct cxl_afu *afu = data; struct cxl_context *ctx; struct cxl_irq_info irq_info; - int ph = cxl_p2n_read(afu, CXL_PSL_PEHandle_An) & 0xffff; - int ret; - + u64 phreg = cxl_p2n_read(afu, CXL_PSL_PEHandle_An); + int ph, ret; + + /* check if eeh kicked in while the interrupt was in flight */ + if (unlikely(phreg == ~0ULL)) { + dev_warn(&afu->dev, + "Ignoring slice interrupt(%d) due to fenced card", + irq); + return IRQ_HANDLED; + } + /* Mask the pe-handle from register value */ + ph = phreg & 0xffff; if ((ret = native_get_irq_info(afu, &irq_info))) { WARN(1, "Unable to get CXL IRQ Info: %i\n", ret); return fail_psl_irq(afu, &irq_info); -- 2.20.1