[SRU][N][PATCH v2 1/1] RDMA/irdma: Suppress PF reset on HMC error

[Seyeong Kim]

BugLink: https://bugs.launchpad.net/bugs/2167995

The irdma driver currently issues an unconditional PF reset whenever the
HMC Error interrupt (PFINT_OICR bit 26) fires:

	if (event->reg & IRDMAPFINT_OICR_HMC_ERR_M) {
		ibdev_err(&iwdev->ibdev, "HMC Error\n");
		iwdev->rf->reset = true;
	}

request_reset() issues an IIDC_PFR to ice. In practice a single HMC_ERR
can trigger cascading PF resets, IOMMU faults during teardown, and
teardown of every RDMA connection on the device.

i40e handles the identically-named interrupt by reading
PFHMC_ERRORINFO and PFHMC_ERRORDATA and logging them without touching
device state; see commit 9c010ee0ea5f ("i40e: Suppress HMC error to
Interrupt message level") which removed the reset as "not necessary".
This patch mirrors that handling on irdma.

With this change, repeated HMC_ERR no longer produces a reset storm and
RDMA traffic on the device continues uninterrupted.

Signed-off-by: Seyeong Kim <seyeong.kim at canonical.com>
Link: https://patch.msgid.link/20260619050044.1807044-1-seyeong.kim@canonical.com
Signed-off-by: Leon Romanovsky <leon at kernel.org>
(backported from commit 4dc9c884c0aafac1e8d37536d88d485135e26883)
[gerald: Upstream modifies the IIDC event handler in icrdma_if.c,
 which does not exist in Noble. Here the handler is in main.c, so the
 identical change is applied there instead. No functional difference.]
Signed-off-by: Gerald Yang <gerald.yang at canonical.com>
Signed-off-by: Seyeong Kim <seyeong.kim at canonical.com>
---
 drivers/infiniband/hw/irdma/i40iw_hw.c  | 4 +++-
 drivers/infiniband/hw/irdma/icrdma_hw.c | 2 ++
 drivers/infiniband/hw/irdma/icrdma_hw.h | 2 ++
 drivers/infiniband/hw/irdma/irdma.h     | 2 ++
 drivers/infiniband/hw/irdma/main.c      | 8 ++++++--
 5 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/irdma/i40iw_hw.c b/drivers/infiniband/hw/irdma/i40iw_hw.c
index ce61a27cb1f6..a241a24c5073 100644
--- a/drivers/infiniband/hw/irdma/i40iw_hw.c
+++ b/drivers/infiniband/hw/irdma/i40iw_hw.c
@@ -29,7 +29,9 @@ static u32 i40iw_regs[IRDMA_MAX_REGS] = {
 	I40E_PFHMC_PDINV,
 	I40E_GLHMC_VFPDINV(0),
 	I40E_GLPE_CRITERR,
-	0xffffffff      /* PFINT_RATEN not used in FPK */
+	0xffffffff,     /* PFINT_RATEN not used in FPK */
+	0xffffffff,     /* PFHMC_ERRORINFO not used in FPK */
+	0xffffffff      /* PFHMC_ERRORDATA not used in FPK */
 };
 
 static u32 i40iw_stat_offsets[] = {
diff --git a/drivers/infiniband/hw/irdma/icrdma_hw.c b/drivers/infiniband/hw/irdma/icrdma_hw.c
index 941d3edffadb..04169b483aa5 100644
--- a/drivers/infiniband/hw/irdma/icrdma_hw.c
+++ b/drivers/infiniband/hw/irdma/icrdma_hw.c
@@ -29,6 +29,8 @@ static u32 icrdma_regs[IRDMA_MAX_REGS] = {
 	GLHMC_VFPDINV(0),
 	GLPE_CRITERR,
 	GLINT_RATE(0),
+	PFHMC_ERRORINFO,
+	PFHMC_ERRORDATA,
 };
 
 static u64 icrdma_masks[IRDMA_MAX_MASKS] = {
diff --git a/drivers/infiniband/hw/irdma/icrdma_hw.h b/drivers/infiniband/hw/irdma/icrdma_hw.h
index 697b9572b5c6..ce1458a86868 100644
--- a/drivers/infiniband/hw/irdma/icrdma_hw.h
+++ b/drivers/infiniband/hw/irdma/icrdma_hw.h
@@ -40,6 +40,8 @@
 #define GLHMC_VFPDINV(_i)	(0x00528300 + ((_i) * 4)) /* _i=0...31 */
 #define GLPE_CRITERR		0x00534000
 #define GLINT_RATE(_INT)	(0x0015A000 + ((_INT) * 4)) /* _i=0...2047 */ /* Reset Source: CORER */
+#define PFHMC_ERRORINFO		0x00520400
+#define PFHMC_ERRORDATA		0x00520500
 
 #define ICRDMA_DB_ADDR_OFFSET		(8 * 1024 * 1024 - 64 * 1024)
 
diff --git a/drivers/infiniband/hw/irdma/irdma.h b/drivers/infiniband/hw/irdma/irdma.h
index 20d2e7393e3d..4ead0bef143c 100644
--- a/drivers/infiniband/hw/irdma/irdma.h
+++ b/drivers/infiniband/hw/irdma/irdma.h
@@ -57,6 +57,8 @@ enum irdma_registers {
 	IRDMA_GLHMC_VFPDINV,
 	IRDMA_GLPE_CRITERR,
 	IRDMA_GLINT_RATE,
+	IRDMA_PFHMC_ERRORINFO,
+	IRDMA_PFHMC_ERRORDATA,
 	IRDMA_MAX_REGS, /* Must be last entry */
 };
 
diff --git a/drivers/infiniband/hw/irdma/main.c b/drivers/infiniband/hw/irdma/main.c
index 3f13200ff71b..b9a8bc1a0979 100644
--- a/drivers/infiniband/hw/irdma/main.c
+++ b/drivers/infiniband/hw/irdma/main.c
@@ -133,8 +133,12 @@ static void irdma_iidc_event_handler(struct ice_pf *pf, struct iidc_event *event
 			}
 		}
 		if (event->reg & IRDMAPFINT_OICR_HMC_ERR_M) {
-			ibdev_err(&iwdev->ibdev, "HMC Error\n");
-			iwdev->rf->reset = true;
+			u32 hmc_errinfo = readl(iwdev->rf->sc_dev.hw_regs[IRDMA_PFHMC_ERRORINFO]);
+			u32 hmc_errdata = readl(iwdev->rf->sc_dev.hw_regs[IRDMA_PFHMC_ERRORDATA]);
+
+			/* Log diagnostics; do not reset here. */
+			ibdev_warn(&iwdev->ibdev, "HMC Error: errinfo=0x%08x errdata=0x%08x\n",
+				   hmc_errinfo, hmc_errdata);
 		}
 		if (event->reg & IRDMAPFINT_OICR_PE_PUSH_M) {
 			ibdev_err(&iwdev->ibdev, "PE Push Error\n");
-- 
2.43.0