pci: support class id probing

This patch is used to add the class_id (class_code,
subclass_code, programming_interface) support for
pci_device probe. With this patch, it will be
flexible for users to probe a class of devices
by class_id.

Signed-off-by: Ziye Yang <ziye.yang@intel.com>

doc/guides/rel_notes/deprecation.rst

@@ -23,12 +23,6 @@ Deprecation Notices
   do not need to care about the kind of devices that are being used, making it
   easier to add new buses later.
 
-* ABI changes are planned for struct rte_pci_id, i.e., add new field ``class``.
-  This new added ``class`` field can be used to probe pci device by class
-  related info. This change should impact size of struct rte_pci_id and struct
-  rte_pci_device. The release 16.04 does not contain these ABI changes, but
-  release 16.07 will.
-
 * The xstats API and rte_eth_xstats struct will be changed to allow retrieval
   of values without any string copies or parsing.
   No backwards compatibility is planned, as it would require code duplication

lib/librte_eal/bsdapp/eal/eal_pci.c

@@ -278,6 +278,11 @@ pci_scan_one(int dev_pci_fd, struct pci_conf *conf)
 	/* get subsystem_device id */
 	dev->id.subsystem_device_id = conf->pc_subdevice;
 
+	/* get class id */
+	dev->id.class_id = (conf->pc_class << 16) |
+			   (conf->pc_subclass << 8) |
+			   (conf->pc_progif);
+
 	/* TODO: get max_vfs */
 	dev->max_vfs = 0;
 

lib/librte_eal/common/eal_common_pci.c

@@ -175,6 +175,9 @@ rte_eal_pci_probe_one_driver(struct rte_pci_driver *dr, struct rte_pci_device *d
 		if (id_table->subsystem_device_id != dev->id.subsystem_device_id &&
 				id_table->subsystem_device_id != PCI_ANY_ID)
 			continue;
+		if (id_table->class_id != dev->id.class_id &&
+				id_table->class_id != RTE_CLASS_ANY_ID)
+			continue;
 
 		struct rte_pci_addr *loc = &dev->addr;
 

lib/librte_eal/common/include/rte_pci.h

@@ -125,6 +125,7 @@ struct rte_pci_resource {
  * table of these IDs for each device that it supports.
  */
 struct rte_pci_id {
+	uint32_t class_id;            /**< Class ID (class, subclass, pi) or RTE_CLASS_ANY_ID. */
 	uint16_t vendor_id;           /**< Vendor ID or PCI_ANY_ID. */
 	uint16_t device_id;           /**< Device ID or PCI_ANY_ID. */
 	uint16_t subsystem_vendor_id; /**< Subsystem vendor ID or PCI_ANY_ID. */
@@ -170,10 +171,12 @@ struct rte_pci_device {
 
 /** Any PCI device identifier (vendor, device, ...) */
 #define PCI_ANY_ID (0xffff)
+#define RTE_CLASS_ANY_ID (0xffffff)
 
 #ifdef __cplusplus
 /** C++ macro used to help building up tables of device IDs */
 #define RTE_PCI_DEVICE(vend, dev) \
+	RTE_CLASS_ANY_ID,         \
 	(vend),                   \
 	(dev),                    \
 	PCI_ANY_ID,               \
@@ -181,6 +184,7 @@ struct rte_pci_device {
 #else
 /** Macro used to help building up tables of device IDs */
 #define RTE_PCI_DEVICE(vend, dev)          \
+	.class_id = RTE_CLASS_ANY_ID,      \
 	.vendor_id = (vend),               \
 	.device_id = (dev),                \
 	.subsystem_vendor_id = PCI_ANY_ID, \

lib/librte_eal/linuxapp/eal/eal_pci.c

@@ -306,6 +306,16 @@ pci_scan_one(const char *dirname, uint16_t domain, uint8_t bus,
 	}
 	dev->id.subsystem_device_id = (uint16_t)tmp;
 
+	/* get class_id */
+	snprintf(filename, sizeof(filename), "%s/class",
+		 dirname);
+	if (eal_parse_sysfs_value(filename, &tmp) < 0) {
+		free(dev);
+		return -1;
+	}
+	/* the least 24 bits are valid: class, subclass, program interface */
+	dev->id.class_id = (uint32_t)tmp & RTE_CLASS_ANY_ID;
+
 	/* get max_vfs */
 	dev->max_vfs = 0;
 	snprintf(filename, sizeof(filename), "%s/max_vfs", dirname);