[PATCH v4 5/8] pci: use given name as generic name

[Gaetan Rivet <gaetan.rivet@6wind.com>]

When an application requests the use of a PCI device, it can currently
interchangeably use either the longform DomBDF format (0000:00:00.0) or
the shorter BDF format (00:00.0).

When a device is inserted via the hotplug API, it must first be scanned
and then will be identified by its name using `find_device`. The name of
the device must match the name given by the user to be found and then
probed.

A new function sets the expected name for a scanned PCI device. It was
previously generated from parsing the PCI address. This canonical name
is superseded when an rte_devargs exists describing the device. In such
case, the device takes the given name found within the rte_devargs.

As the rte_devargs is linked to the rte_pci_device during scanning, it
can be avoided during the probe. Additionally, this fixes the issue of
the rte_devargs lookup not being done within rte_pci_probe_one.

Fixes: beec692c5157 ("eal: add name field to generic device")
Cc: stable@dpdk.org

Signed-off-by: Gaetan Rivet <gaetan.rivet@6wind.com>
---
 lib/librte_eal/bsdapp/eal/eal_pci.c    |  4 ++--
 lib/librte_eal/common/eal_common_pci.c | 29 ++++++++++++++++++++++++-----
 lib/librte_eal/common/eal_private.h    |  5 +++++
 lib/librte_eal/linuxapp/eal/eal_pci.c  |  4 ++--
 4 files changed, 33 insertions(+), 9 deletions(-)

diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c b/lib/librte_eal/bsdapp/eal/eal_pci.c
index e321461..97a88ec 100644
--- a/lib/librte_eal/bsdapp/eal/eal_pci.c
+++ b/lib/librte_eal/bsdapp/eal/eal_pci.c
@@ -282,8 +282,7 @@ pci_scan_one(int dev_pci_fd, struct pci_conf *conf)
 	/* FreeBSD has no NUMA support (yet) */
 	dev->device.numa_node = 0;
 
-	rte_pci_device_name(&dev->addr, dev->name, sizeof(dev->name));
-	dev->device.name = dev->name;
+	pci_name_set(dev);
 
 	/* FreeBSD has only one pass through driver */
 	dev->kdrv = RTE_KDRV_NIC_UIO;
@@ -334,6 +333,7 @@ pci_scan_one(int dev_pci_fd, struct pci_conf *conf)
 			} else { /* already registered */
 				dev2->kdrv = dev->kdrv;
 				dev2->max_vfs = dev->max_vfs;
+				pci_name_set(dev2);
 				memmove(dev2->mem_resource,
 					dev->mem_resource,
 					sizeof(dev->mem_resource));
diff --git a/lib/librte_eal/common/eal_common_pci.c b/lib/librte_eal/common/eal_common_pci.c
index 76bbcc8..45e697e 100644
--- a/lib/librte_eal/common/eal_common_pci.c
+++ b/lib/librte_eal/common/eal_common_pci.c
@@ -88,6 +88,29 @@ static struct rte_devargs *pci_devargs_lookup(struct rte_pci_device *dev)
 	return NULL;
 }
 
+void
+pci_name_set(struct rte_pci_device *dev)
+{
+	struct rte_devargs *devargs;
+
+	/* Each device has its internal, canonical name set. */
+	rte_pci_device_name(&dev->addr,
+			dev->name, sizeof(dev->name));
+	devargs = pci_devargs_lookup(dev);
+	dev->device.devargs = devargs;
+	/* In blacklist mode, if the device is not blacklisted, no
+	 * rte_devargs exists for it.
+	 */
+	if (devargs != NULL)
+		/* If an rte_devargs exists, the generic rte_device uses the
+		 * given name as its namea
+		 */
+		dev->device.name = dev->device.devargs->name;
+	else
+		/* Otherwise, it uses the internal, canonical form. */
+		dev->device.name = dev->name;
+}
+
 /* map a particular resource from a file */
 void *
 pci_map_resource(void *requested_addr, int fd, off_t offset, size_t size,
@@ -396,11 +419,7 @@ rte_pci_probe(void)
 	FOREACH_DEVICE_ON_PCIBUS(dev) {
 		probed++;
 
-		/* set devargs in PCI structure */
-		devargs = pci_devargs_lookup(dev);
-		if (devargs != NULL)
-			dev->device.devargs = devargs;
-
+		devargs = dev->device.devargs;
 		/* probe all or only whitelisted devices */
 		if (probe_all)
 			ret = pci_probe_all_drivers(dev);
diff --git a/lib/librte_eal/common/eal_private.h b/lib/librte_eal/common/eal_private.h
index 0836339..597d82e 100644
--- a/lib/librte_eal/common/eal_private.h
+++ b/lib/librte_eal/common/eal_private.h
@@ -113,6 +113,11 @@ struct rte_pci_driver;
 struct rte_pci_device;
 
 /**
+ * Find the name of a PCI device.
+ */
+void pci_name_set(struct rte_pci_device *dev);
+
+/**
  * Add a PCI device to the PCI Bus (append to PCI Device list). This function
  * also updates the bus references of the PCI Device (and the generic device
  * object embedded within.
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
index 7d9e1a9..556ae2c 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
@@ -324,8 +324,7 @@ pci_scan_one(const char *dirname, const struct rte_pci_addr *addr)
 		dev->device.numa_node = 0;
 	}
 
-	rte_pci_device_name(addr, dev->name, sizeof(dev->name));
-	dev->device.name = dev->name;
+	pci_name_set(dev);
 
 	/* parse resources */
 	snprintf(filename, sizeof(filename), "%s/resource", dirname);
@@ -373,6 +372,7 @@ pci_scan_one(const char *dirname, const struct rte_pci_addr *addr)
 			} else { /* already registered */
 				dev2->kdrv = dev->kdrv;
 				dev2->max_vfs = dev->max_vfs;
+				pci_name_set(dev2);
 				memmove(dev2->mem_resource, dev->mem_resource,
 					sizeof(dev->mem_resource));
 				free(dev);
-- 
2.1.4