[dpdk-dev] [PATCH V4 2/9] bus/pci: implement hotplug handler operation

[Jeff Guo <jia.guo@intel.com>]

This patch implements the ops of hotplug handler for PCI bus, it is
functional to remap a new dummy memory which overlap to the failure
memory to avoid MMIO read/write error.

Signed-off-by: Jeff Guo <jia.guo@intel.com>
---
v4->v3:
split patches to be small and clear.
---
 drivers/bus/pci/pci_common.c     | 28 ++++++++++++++++++++++++++++
 drivers/bus/pci/pci_common_uio.c | 33 +++++++++++++++++++++++++++++++++
 drivers/bus/pci/private.h        | 12 ++++++++++++
 3 files changed, 73 insertions(+)

diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c
index d8151b0..095cd4e 100644
--- a/drivers/bus/pci/pci_common.c
+++ b/drivers/bus/pci/pci_common.c
@@ -401,6 +401,33 @@ pci_find_device(const struct rte_device *start, rte_dev_cmp_t cmp,
 }
 
 static int
+pci_hotplug_handler(struct rte_device *dev)
+{
+	struct rte_pci_device *pdev = NULL;
+	int ret = 0;
+
+	pdev = RTE_DEV_TO_PCI(dev);
+	if (!pdev)
+		return -1;
+
+	switch (pdev->kdrv) {
+	case RTE_KDRV_IGB_UIO:
+	case RTE_KDRV_UIO_GENERIC:
+	case RTE_KDRV_NIC_UIO:
+		/* mmio resources is invalid, remap it to be safe. */
+		ret = pci_uio_remap_resource(pdev);
+		break;
+	default:
+		RTE_LOG(DEBUG, EAL,
+			"Not managed by a supported kernel driver, skipped\n");
+		ret = -1;
+		break;
+	}
+
+	return ret;
+}
+
+static int
 pci_plug(struct rte_device *dev)
 {
 	return pci_probe_all_drivers(RTE_DEV_TO_PCI(dev));
@@ -430,6 +457,7 @@ struct rte_pci_bus rte_pci_bus = {
 		.unplug = pci_unplug,
 		.parse = pci_parse,
 		.get_iommu_class = rte_pci_get_iommu_class,
+		.hotplug_handler = pci_hotplug_handler,
 	},
 	.device_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.device_list),
 	.driver_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.driver_list),
diff --git a/drivers/bus/pci/pci_common_uio.c b/drivers/bus/pci/pci_common_uio.c
index 54bc20b..7ea73db 100644
--- a/drivers/bus/pci/pci_common_uio.c
+++ b/drivers/bus/pci/pci_common_uio.c
@@ -146,6 +146,39 @@ pci_uio_unmap(struct mapped_pci_resource *uio_res)
 	}
 }
 
+/* remap the PCI resource of a PCI device in anonymous virtual memory */
+int
+pci_uio_remap_resource(struct rte_pci_device *dev)
+{
+	int i;
+	void *map_address;
+
+	if (dev == NULL)
+		return -1;
+
+	/* Remap all BARs */
+	for (i = 0; i != PCI_MAX_RESOURCE; i++) {
+		/* skip empty BAR */
+		if (dev->mem_resource[i].phys_addr == 0)
+			continue;
+		map_address = mmap(dev->mem_resource[i].addr,
+				(size_t)dev->mem_resource[i].len,
+				PROT_READ | PROT_WRITE,
+				MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0);
+		if (map_address == MAP_FAILED) {
+			RTE_LOG(ERR, EAL,
+				"Cannot remap resource for device %s\n",
+				dev->name);
+			return -1;
+		}
+		RTE_LOG(INFO, EAL,
+			"Successful remap resource for device %s\n",
+			dev->name);
+	}
+
+	return 0;
+}
+
 static struct mapped_pci_resource *
 pci_uio_find_resource(struct rte_pci_device *dev)
 {
diff --git a/drivers/bus/pci/private.h b/drivers/bus/pci/private.h
index 8ddd03e..6b312e5 100644
--- a/drivers/bus/pci/private.h
+++ b/drivers/bus/pci/private.h
@@ -123,6 +123,18 @@ void pci_uio_free_resource(struct rte_pci_device *dev,
 		struct mapped_pci_resource *uio_res);
 
 /**
+ * Remap the PCI resource of a PCI device in anonymous virtual memory.
+ *
+ * @param dev
+ *   Point to the struct rte pci device.
+ * @return
+ *   - On success, zero.
+ *   - On failure, a negative value.
+ */
+int
+pci_uio_remap_resource(struct rte_pci_device *dev);
+
+/**
  * Map device memory to uio resource
  *
  * This function is private to EAL.
-- 
2.7.4