linux-kernel - [PATCH AUTOSEL 5.13 16/88] iommu/amd: Fix printing of IOMMU events when rate limiting kicks in

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Date:   Thu,  9 Sep 2021 20:17:08 -0400
From:   Sasha Levin <sashal@...nel.org>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:     Lennert Buytenhek <buytenh@...tstofly.org>,
        Suravee Suthikulpanit <suravee.suthikulpanit@....com>,
        Joerg Roedel <jroedel@...e.de>,
        Sasha Levin <sashal@...nel.org>,
        iommu@...ts.linux-foundation.org
Subject: [PATCH AUTOSEL 5.13 16/88] iommu/amd: Fix printing of IOMMU events when rate limiting kicks in

From: Lennert Buytenhek <buytenh@...tstofly.org>

[ Upstream commit ee974d9625c405977ef5d9aedc476be1d0362ebf ]

For the printing of RMP_HW_ERROR / RMP_PAGE_FAULT / IO_PAGE_FAULT
events, the AMD IOMMU code uses such logic:

	if (pdev)
		dev_data = dev_iommu_priv_get(&pdev->dev);

	if (dev_data && __ratelimit(&dev_data->rs)) {
		pci_err(pdev, ...
	} else {
		printk_ratelimit() / pr_err{,_ratelimited}(...
	}

This means that if we receive an event for a PCI devid which actually
does have a struct pci_dev and an attached struct iommu_dev_data, but
rate limiting kicks in, we'll fall back to the non-PCI branch of the
test, and print the event in a different format.

Fix this by changing the logic to:

	if (dev_data) {
		if (__ratelimit(&dev_data->rs)) {
			pci_err(pdev, ...
		}
	} else {
		pr_err_ratelimited(...
	}

Suggested-by: Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Signed-off-by: Lennert Buytenhek <buytenh@...tstofly.org>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@....com>
Link: https://lore.kernel.org/r/YPgk1dD1gPMhJXgY@wantstofly.org
Signed-off-by: Joerg Roedel <jroedel@...e.de>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 drivers/iommu/amd/iommu.c | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index c46dde88a132..69d441fc1e32 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -425,9 +425,11 @@ static void amd_iommu_report_rmp_hw_error(volatile u32 *event)
 	if (pdev)
 		dev_data = dev_iommu_priv_get(&pdev->dev);
 
-	if (dev_data && __ratelimit(&dev_data->rs)) {
-		pci_err(pdev, "Event logged [RMP_HW_ERROR vmg_tag=0x%04x, spa=0x%llx, flags=0x%04x]\n",
-			vmg_tag, spa, flags);
+	if (dev_data) {
+		if (__ratelimit(&dev_data->rs)) {
+			pci_err(pdev, "Event logged [RMP_HW_ERROR vmg_tag=0x%04x, spa=0x%llx, flags=0x%04x]\n",
+				vmg_tag, spa, flags);
+		}
 	} else {
 		pr_err_ratelimited("Event logged [RMP_HW_ERROR device=%02x:%02x.%x, vmg_tag=0x%04x, spa=0x%llx, flags=0x%04x]\n",
 			PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
@@ -456,9 +458,11 @@ static void amd_iommu_report_rmp_fault(volatile u32 *event)
 	if (pdev)
 		dev_data = dev_iommu_priv_get(&pdev->dev);
 
-	if (dev_data && __ratelimit(&dev_data->rs)) {
-		pci_err(pdev, "Event logged [RMP_PAGE_FAULT vmg_tag=0x%04x, gpa=0x%llx, flags_rmp=0x%04x, flags=0x%04x]\n",
-			vmg_tag, gpa, flags_rmp, flags);
+	if (dev_data) {
+		if (__ratelimit(&dev_data->rs)) {
+			pci_err(pdev, "Event logged [RMP_PAGE_FAULT vmg_tag=0x%04x, gpa=0x%llx, flags_rmp=0x%04x, flags=0x%04x]\n",
+				vmg_tag, gpa, flags_rmp, flags);
+		}
 	} else {
 		pr_err_ratelimited("Event logged [RMP_PAGE_FAULT device=%02x:%02x.%x, vmg_tag=0x%04x, gpa=0x%llx, flags_rmp=0x%04x, flags=0x%04x]\n",
 			PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
@@ -480,11 +484,13 @@ static void amd_iommu_report_page_fault(u16 devid, u16 domain_id,
 	if (pdev)
 		dev_data = dev_iommu_priv_get(&pdev->dev);
 
-	if (dev_data && __ratelimit(&dev_data->rs)) {
-		pci_err(pdev, "Event logged [IO_PAGE_FAULT domain=0x%04x address=0x%llx flags=0x%04x]\n",
-			domain_id, address, flags);
-	} else if (printk_ratelimit()) {
-		pr_err("Event logged [IO_PAGE_FAULT device=%02x:%02x.%x domain=0x%04x address=0x%llx flags=0x%04x]\n",
+	if (dev_data) {
+		if (__ratelimit(&dev_data->rs)) {
+			pci_err(pdev, "Event logged [IO_PAGE_FAULT domain=0x%04x address=0x%llx flags=0x%04x]\n",
+				domain_id, address, flags);
+		}
+	} else {
+		pr_err_ratelimited("Event logged [IO_PAGE_FAULT device=%02x:%02x.%x domain=0x%04x address=0x%llx flags=0x%04x]\n",
 			PCI_BUS_NUM(devid), PCI_SLOT(devid), PCI_FUNC(devid),
 			domain_id, address, flags);
 	}
-- 
2.30.2