[dpdk-dev] [PATCH] igb_uio: fix unknown symbols

[Ferruh Yigit <ferruh.yigit@intel.com>]

This patch partially reverts the commit d196343a258e and adds some
functions from Markus' previous version of the patch [1].

igb_uio uses pci_msi_unmask_irq() and pci_msi_mask_irq() kernel APIs
when kernel version is >= 3.19 because these APIs are implemented in
this Linux kernel version.

But these APIs only exported beginning from Linux kernel 4.5, so before
this Linux kernel version igb_uio kernel module is not usable,
and giving following warnings:
"igb_uio: Unknown symbol pci_msi_unmask_irq"
"igb_uio: Unknown symbol pci_msi_mask_irq"

The support for these APIs increased to Linux kernel >= 4.5

For older version of Linux kernel unmask_msi_irq() and mask_msi_irq()
are used but these functions are not exported at all.
Instead of these functions switched back to previous implementation in
igb_uio for MSI-X, and for MSI used igbuio_msi_mask_irq() from [1].

Fixes: d196343a258e ("igb_uio: use kernel functions for masking MSI-X")
Cc: markus.theil@tu-ilmenau.de

[1]
http://dpdk.org/dev/patchwork/patch/28144/

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
 lib/librte_eal/linuxapp/igb_uio/compat.h  | 25 ++++++++--
 lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 77 ++++++++++++++++++++++++++++---
 2 files changed, 91 insertions(+), 11 deletions(-)

diff --git a/lib/librte_eal/linuxapp/igb_uio/compat.h b/lib/librte_eal/linuxapp/igb_uio/compat.h
index 67a7ab3af..30508f35c 100644
--- a/lib/librte_eal/linuxapp/igb_uio/compat.h
+++ b/lib/librte_eal/linuxapp/igb_uio/compat.h
@@ -15,6 +15,21 @@
 #define HAVE_PTE_MASK_PAGE_IOMAP
 #endif
 
+#ifndef PCI_MSIX_ENTRY_SIZE
+#define PCI_MSIX_ENTRY_SIZE            16
+#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)))
@@ -110,10 +125,12 @@ static bool pci_check_and_mask_intx(struct pci_dev *pdev)
 #define HAVE_ALLOC_IRQ_VECTORS 1
 #endif
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 19, 0)
-#define HAVE_PCI_MSI_MASK_IRQ 1
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 3, 0)
+#define HAVE_MSI_LIST_IN_GENERIC_DEVICE 1
 #endif
 
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 37)
-#define HAVE_IRQ_DATA 1
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0)
+#define HAVE_PCI_MSI_MASK_IRQ 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 c8dd5f4d0..2663a8f66 100644
--- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
+++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
@@ -90,6 +90,74 @@ static const struct attribute_group dev_attr_grp = {
 	.attrs = dev_attrs,
 };
 
+#ifndef HAVE_PCI_MSI_MASK_IRQ
+/*
+ * It masks the msix on/off of generating MSI-X messages.
+ */
+static void
+igbuio_msix_mask_irq(struct msi_desc *desc, s32 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;
+	}
+}
+
+static void
+igbuio_mask_irq(struct pci_dev *pdev, enum rte_intr_mode mode, s32 irq_state)
+{
+	struct msi_desc *desc;
+	struct list_head *msi_list;
+
+#ifdef HAVE_MSI_LIST_IN_GENERIC_DEVICE
+	msi_list = &pdev->dev.msi_list;
+#else
+	msi_list = &pdev->msi_list;
+#endif
+
+	if (mode == RTE_INTR_MODE_MSIX) {
+		list_for_each_entry(desc, msi_list, list)
+			igbuio_msix_mask_irq(desc, irq_state);
+	} else if (mode == RTE_INTR_MODE_MSI) {
+		list_for_each_entry(desc, msi_list, list)
+			igbuio_msi_mask_irq(pdev, desc, irq_state);
+	}
+}
+#endif
+
 /**
  * This is the irqcontrol callback to be registered to uio_info.
  * It can be used to disable/enable interrupt from user space processes.
@@ -109,10 +177,8 @@ igbuio_pci_irqcontrol(struct uio_info *info, s32 irq_state)
 	struct rte_uio_pci_dev *udev = info->priv;
 	struct pci_dev *pdev = udev->pdev;
 
-#ifdef HAVE_IRQ_DATA
+#ifdef HAVE_PCI_MSI_MASK_IRQ
 	struct irq_data *irq = irq_get_irq_data(udev->info.irq);
-#else
-	unsigned int irq = udev->info.irq;
 #endif
 
 	pci_cfg_access_lock(pdev);
@@ -124,10 +190,7 @@ igbuio_pci_irqcontrol(struct uio_info *info, s32 irq_state)
 		else
 			pci_msi_mask_irq(irq);
 #else
-		if (irq_state == 1)
-			unmask_msi_irq(irq);
-		else
-			mask_msi_irq(irq);
+		igbuio_mask_irq(pdev, udev->mode, irq_state);
 #endif
 	}
 
-- 
2.13.6