[dpdk-dev] [PATCH V18 2/5] bus/pci: implement handle hot unplug operation

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

When handle device hot unplug event, remap a dummy memory to avoid
bus read/write error.

Signed-off-by: Jeff Guo <jia.guo@intel.com>
---
v16->v15;
split patch, merge some function to be simple
---
 drivers/bus/pci/pci_common.c     | 42 ++++++++++++++++++++++++++++++++++++++++
 drivers/bus/pci/pci_common_uio.c | 33 +++++++++++++++++++++++++++++++
 drivers/bus/pci/private.h        | 12 ++++++++++++
 3 files changed, 87 insertions(+)

diff --git a/drivers/bus/pci/pci_common.c b/drivers/bus/pci/pci_common.c
index 2a00f36..fa077ec 100644
--- a/drivers/bus/pci/pci_common.c
+++ b/drivers/bus/pci/pci_common.c
@@ -474,6 +474,47 @@ pci_find_device(const struct rte_device *start, rte_dev_cmp_t cmp,
 }
 
 static int
+pci_handle_hot_unplug(struct rte_device *dev)
+{
+	struct rte_pci_device *pdev;
+	int ret;
+
+	if (dev == NULL)
+		return -EINVAL;
+
+	pdev = RTE_DEV_TO_PCI(dev);
+
+	/* remap resources for devices */
+	switch (pdev->kdrv) {
+	case RTE_KDRV_VFIO:
+#ifdef VFIO_PRESENT
+		/* TODO */
+#endif
+		break;
+	case RTE_KDRV_IGB_UIO:
+	case RTE_KDRV_UIO_GENERIC:
+		if (rte_eal_using_phys_addrs()) {
+			/* map resources for devices that use uio */
+			ret = pci_uio_remap_resource(pdev);
+		}
+		break;
+	case RTE_KDRV_NIC_UIO:
+		ret = pci_uio_remap_resource(pdev);
+		break;
+	default:
+		RTE_LOG(DEBUG, EAL,
+			"  Not managed by a supported kernel driver, skipped\n");
+		ret = 1;
+		break;
+	}
+
+	if (ret != 0)
+		RTE_LOG(ERR, EAL, "failed to handle hot unplug of %s",
+			pdev->name);
+	return ret;
+}
+
+static int
 pci_plug(struct rte_device *dev)
 {
 	return pci_probe_all_drivers(RTE_DEV_TO_PCI(dev));
@@ -503,6 +544,7 @@ struct rte_pci_bus rte_pci_bus = {
 		.unplug = pci_unplug,
 		.parse = pci_parse,
 		.get_iommu_class = rte_pci_get_iommu_class,
+		.handle_hot_unplug = pci_handle_hot_unplug,
 	},
 	.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..468ade4 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 private virtual memory */
+int
+pci_uio_remap_resource(struct rte_pci_device *dev)
+{
+	int i;
+	uint64_t phaddr;
+	void *map_address;
+
+	if (dev == NULL)
+		return -1;
+
+	/* Map all BARs */
+	for (i = 0; i != PCI_MAX_RESOURCE; i++) {
+		/* skip empty BAR */
+		phaddr = dev->mem_resource[i].phys_addr;
+		if (phaddr == 0)
+			continue;
+		pci_unmap_resource(dev->mem_resource[i].addr,
+				(size_t)dev->mem_resource[i].len);
+		map_address = pci_map_resource(
+				dev->mem_resource[i].addr, -1, 0,
+				(size_t)dev->mem_resource[i].len,
+				MAP_ANONYMOUS | MAP_FIXED);
+		if (map_address == MAP_FAILED) {
+			RTE_LOG(ERR, EAL,
+				"Cannot remap resource for device %s\n", dev->name);
+			return -1;
+		}
+	}
+
+	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 88fa587..7a862ef 100644
--- a/drivers/bus/pci/private.h
+++ b/drivers/bus/pci/private.h
@@ -173,6 +173,18 @@ void pci_uio_free_resource(struct rte_pci_device *dev,
 		struct mapped_pci_resource *uio_res);
 
 /**
+ * remap the pci uio resource..
+ *
+ * @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