Re: [dpdk-dev] [PATCH v7 5/6] igb_uio: use kernel functions for masking MSI-X

["Kavanagh, Mark B" <mark.b.kavanagh@intel.com>]

Hi,

This commit renders igb_uio unusable on Fedora 20, kernel version 3.19.8-100.fc20.x86_64.

During the build (make -j 20), a warning is issued for igb_uio regarding a missing symbol (pci_msi_unmask):
	WARNING: "pci_msi_unmask_irq" [/home/<redacted>/x86_64-native-linuxapp-gcc/build/lib/librte_eal/linuxapp/igb_uio/igb_uio.ko] undefined!
	WARNING: "pci_msi_mask_irq" [/home/<redacted>/x86_64-native-linuxapp-gcc/build/lib/librte_eal/linuxapp/igb_uio/igb_uio.ko] undefined!

Subsequently, the module is may not be loaded on account of same.
(from dmesg): 
	[673425.712110] igb_uio: Unknown symbol pci_msi_unmask_irq (err 0)
	[673425.712124] igb_uio: Unknown symbol pci_msi_mask_irq (err 0)

Thanks,
Mark

>-----Original Message-----
>From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Markus Theil
>Sent: Tuesday, September 5, 2017 1:04 PM
>To: dev@dpdk.org
>Cc: Yigit, Ferruh <ferruh.yigit@intel.com>; stephen@networkplumber.org; Markus
>Theil <markus.theil@tu-ilmenau.de>
>Subject: [dpdk-dev] [PATCH v7 5/6] igb_uio: use kernel functions for masking
>MSI-X
>
>This patch removes the custom MSI-X mask/unmask code and
>uses already existing kernel functions.
>
>Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
>---
> lib/librte_eal/linuxapp/igb_uio/compat.h  | 26 +++++-----------
> lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 51 ++++++++++++------------------
>-
> 2 files changed, 28 insertions(+), 49 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 c570eed..e4ef817 100644
>--- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
>+++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
>@@ -91,27 +91,6 @@ static struct attribute *dev_attrs[] = {
> 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;
>-	}
>-}
>
> /**
>  * This is the irqcontrol callback to be registered to uio_info.
>@@ -132,21 +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);
>+#ifdef HAVE_IRQ_DATA
>+	struct irq_data *irq = irq_get_irq_data(udev->info.irq);
>+#else
>+	unsigned int irq = udev->info.irq;
>+#endif
>
>-	else if (udev->mode == RTE_INTR_MODE_MSIX) {
>-		struct msi_desc *desc;
>+	pci_cfg_access_lock(pdev);
>
>-#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);
>+	if (udev->mode == RTE_INTR_MODE_MSIX) {
>+#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_msix_mask_irq(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;
>--
>2.7.4