Re: [PATCH v5 4/5] igb_uio: use msi mask functions from kernel, little corrections

From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Markus Theil
Sent: Thursday, August 31, 2017 10:47 PM
To: dev@dpdk.org
Cc: Yigit, Ferruh <redacted>; stephen@networkplumber.org;
Markus Theil [off-list ref]
Subject: [dpdk-dev] [PATCH v5 4/5] igb_uio: use msi mask functions from
kernel, little corrections

This patch substitutes the custom MSI/MSI-X mask code and uses already
existing kernel APIs. Feedback/small corrections to the previous patch of this
series are also incorporated.

Signed-off-by: Markus Theil <redacted>
---
 lib/librte_eal/linuxapp/igb_uio/compat.h  | 26 +++------
lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 88 ++++++++-----------------------
 2 files changed, 31 insertions(+), 83 deletions(-)

diff --git a/lib/librte_eal/linuxapp/igb_uio/compat.h

b/lib/librte_eal/linuxapp/igb_uio/compat.h
index 3825933..67a7ab3 100644

--- a/lib/librte_eal/linuxapp/igb_uio/compat.h
+++ b/lib/librte_eal/linuxapp/igb_uio/compat.h

@@ -15,24 +15,6 @@
 #define HAVE_PTE_MASK_PAGE_IOMAP
 #endif

-#ifndef PCI_MSIX_ENTRY_SIZE
-#define PCI_MSIX_ENTRY_SIZE             16
-#define  PCI_MSIX_ENTRY_LOWER_ADDR      0
-#define  PCI_MSIX_ENTRY_UPPER_ADDR      4
-#define  PCI_MSIX_ENTRY_DATA            8
-#define  PCI_MSIX_ENTRY_VECTOR_CTRL     12
-#define   PCI_MSIX_ENTRY_CTRL_MASKBIT   1
-#endif
-
-/*
- * for kernels < 2.6.38 and backported patch that moves MSI-X entry

definition
- * to pci_regs.h Those kernels has PCI_MSIX_ENTRY_SIZE defined but not
- * PCI_MSIX_ENTRY_CTRL_MASKBIT
- */
-#ifndef PCI_MSIX_ENTRY_CTRL_MASKBIT
-#define PCI_MSIX_ENTRY_CTRL_MASKBIT    1
-#endif
-
 #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 34) && \
 	(!(defined(RHEL_RELEASE_CODE) && \
 	 RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(5, 9))) @@ -127,3
+109,11 @@ static bool pci_check_and_mask_intx(struct pci_dev *pdev)  #if
LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)  #define
HAVE_ALLOC_IRQ_VECTORS 1  #endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 19, 0) #define
+HAVE_PCI_MSI_MASK_IRQ 1 #endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 37) #define
+HAVE_IRQ_DATA 1 #endif

diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c

b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
index 99a085a..5830453 100644

--- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
+++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c

@@ -92,51 +92,6 @@ static const struct attribute_group dev_attr_grp = {
 	.attrs = dev_attrs,
 };

-/*
- * It masks the msix on/off of generating MSI-X messages.
- */
-static void
-igbuio_msix_mask_irq(struct msi_desc *desc, int32_t state) -{
-	u32 mask_bits = desc->masked;
-	unsigned offset = desc->msi_attrib.entry_nr *

PCI_MSIX_ENTRY_SIZE +
-
	PCI_MSIX_ENTRY_VECTOR_CTRL;
-
-	if (state != 0)
-		mask_bits &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
-	else
-		mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
-
-	if (mask_bits != desc->masked) {
-		writel(mask_bits, desc->mask_base + offset);
-		readl(desc->mask_base);
-		desc->masked = mask_bits;
-	}
-}
-
-/*
- * It masks the msi on/off of generating MSI messages.
- */
-static void
-igbuio_msi_mask_irq(struct pci_dev *pdev, struct msi_desc *desc, int32_t
state) -{
-	u32 mask_bits = desc->masked;
-	u32 offset = desc->irq - pdev->irq;
-	u32 mask = 1 << offset;
-	u32 flag = !!state << offset;
-
-	if (!desc->msi_attrib.maskbit)
-		return;
-
-	mask_bits &= ~mask;
-	mask_bits |= flag;
-
-	if (mask_bits != desc->masked) {
-		pci_write_config_dword(pdev, desc->mask_pos, mask_bits);
-		desc->masked = mask_bits;
-	}
-}
-
 /**
  * This is the irqcontrol callback to be registered to uio_info.
  * It can be used to disable/enable interrupt from user space processes.

@@ -156,31 +111,31 @@ igbuio_pci_irqcontrol(struct uio_info *info, s32

irq_state)
 	struct rte_uio_pci_dev *udev = info->priv;
 	struct pci_dev *pdev = udev->pdev;

-	pci_cfg_access_lock(pdev);
-	if (udev->mode == RTE_INTR_MODE_LEGACY)
-		pci_intx(pdev, !!irq_state);
-
-	else if (udev->mode == RTE_INTR_MODE_MSIX) {
-		struct msi_desc *desc;
-
-#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0))
-		list_for_each_entry(desc, &pdev->msi_list, list)
-			igbuio_msix_mask_irq(desc, irq_state);
+#ifdef HAVE_IRQ_DATA
+	struct irq_data *irq = irq_get_irq_data(udev->info.irq);
 #else
-		list_for_each_entry(desc, &pdev->dev.msi_list, list)
-			igbuio_msix_mask_irq(desc, irq_state);
+	unsigned int irq = udev->info.irq;
 #endif
-	} else if (udev->mode == RTE_INTR_MODE_MSI) {
-	struct msi_desc *desc;

-#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 3, 0))
-	list_for_each_entry(desc, &pdev->msi_list, list)
-		igbuio_msi_mask_irq(pdev, desc, irq_state);
+	pci_cfg_access_lock(pdev);
+
+	if (udev->mode == RTE_INTR_MODE_MSIX || udev->mode ==
+RTE_INTR_MODE_MSI) { #ifdef HAVE_PCI_MSI_MASK_IRQ
+		if (irq_state == 1)
+			pci_msi_unmask_irq(irq);
+		else
+			pci_msi_mask_irq(irq);
 #else
-	list_for_each_entry(desc, &pdev->dev.msi_list, list)
-		igbuio_msi_mask_irq(pdev, desc, irq_state);
+		if (irq_state == 1)
+			unmask_msi_irq(irq);
+		else
+			mask_msi_irq(irq);
 #endif
 	}
+
+	if (udev->mode == RTE_INTR_MODE_LEGACY)
+		pci_intx(pdev, !!irq_state);
+
 	pci_cfg_access_unlock(pdev);

 	return 0;

@@ -365,11 +320,13 @@ igbuio_pci_enable_interrupts(struct

rte_uio_pci_dev *udev)  #else
 		if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSIX) ==
1) {
 			dev_dbg(&udev->pdev->dev, "using MSI-X");
+			udev->info.irq_flags = IRQF_NO_THREAD;

 			udev->info.irq = pci_irq_vector(udev->pdev, 0);
 			udev->mode = RTE_INTR_MODE_MSIX;
 			break;
 		}
 #endif
+	/* fall back to MSI */
 	case RTE_INTR_MODE_MSI:
 #ifndef HAVE_ALLOC_IRQ_VECTORS
 		if (pci_enable_msi(udev->pdev) == 0) { @@ -382,6 +339,7

@@ igbuio_pci_enable_interrupts(struct rte_uio_pci_dev *udev)  #else
 		if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSI) ==

1) {
 			dev_dbg(&udev->pdev->dev, "using MSI");
+			udev->info.irq_flags = IRQF_NO_THREAD;
 			udev->info.irq = pci_irq_vector(udev->pdev, 0);
 			udev->mode = RTE_INTR_MODE_MSI;
 			break;

@@ -397,7 +355,7 @@ igbuio_pci_enable_interrupts(struct rte_uio_pci_dev

*udev)
 			break;
 		}
 		dev_notice(&udev->pdev->dev, "PCI INTX mask not
supported\n");
-		/* fall back to no IRQ */
+	/* fall back to no IRQ */
 	case RTE_INTR_MODE_NONE:
 		udev->mode = RTE_INTR_MODE_NONE;
 		udev->info.irq = 0;
--
2.7.4