pci: add bus driver

Based on EAL Bus APIs, PCI bus callbacks and support functions are
introduced in this patch.

EAL continues to have direct PCI init/scan calls as well. These would be
removed in subsequent patches to enable bus only PCI devices.

Signed-off-by: Shreyansh Jain <shreyansh.jain@nxp.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit@intel.com>
Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
Reviewed-by: Gaetan Rivet <gaetan.rivet@6wind.com>
Acked-by: Stephen Hemminger <stephen@networkplumber.org>

lib/librte_eal/bsdapp/eal/eal_pci.c

@@ -87,6 +87,8 @@
  * enabling bus master.
  */
 
+extern struct rte_pci_bus rte_pci_bus;
+
 /* Map pci device */
 int
 rte_eal_pci_map_device(struct rte_pci_device *dev)

lib/librte_eal/common/eal_common_pci.c

@@ -72,6 +72,7 @@
 #include <rte_errno.h>
 #include <rte_interrupts.h>
 #include <rte_log.h>
+#include <rte_bus.h>
 #include <rte_pci.h>
 #include <rte_per_lcore.h>
 #include <rte_memory.h>
@@ -88,6 +89,8 @@ struct pci_driver_list pci_driver_list =
 struct pci_device_list pci_device_list =
 	TAILQ_HEAD_INITIALIZER(pci_device_list);
 
+extern struct rte_pci_bus rte_pci_bus;
+
 #define SYSFS_PCI_DEVICES "/sys/bus/pci/devices"
 
 const char *pci_get_sysfs_path(void)
@@ -489,3 +492,36 @@ rte_eal_pci_unregister(struct rte_pci_driver *driver)
 	rte_eal_driver_unregister(&driver->driver);
 	TAILQ_REMOVE(&pci_driver_list, driver, next);
 }
+
+/* Add a device to PCI bus */
+void
+rte_eal_pci_add_device(struct rte_pci_device *pci_dev)
+{
+	TAILQ_INSERT_TAIL(&rte_pci_bus.device_list, pci_dev, next);
+}
+
+/* Insert a device into a predefined position in PCI bus */
+void
+rte_eal_pci_insert_device(struct rte_pci_device *exist_pci_dev,
+			  struct rte_pci_device *new_pci_dev)
+{
+	TAILQ_INSERT_BEFORE(exist_pci_dev, new_pci_dev, next);
+}
+
+/* Remove a device from PCI bus */
+void
+rte_eal_pci_remove_device(struct rte_pci_device *pci_dev)
+{
+	TAILQ_REMOVE(&rte_pci_bus.device_list, pci_dev, next);
+}
+
+struct rte_pci_bus rte_pci_bus = {
+	.bus = {
+		.scan = rte_eal_pci_scan,
+		.probe = rte_eal_pci_probe,
+	},
+	.device_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.device_list),
+	.driver_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.driver_list),
+};
+
+RTE_REGISTER_BUS(PCI_BUS_NAME, rte_pci_bus.bus);

lib/librte_eal/common/eal_private.h

@@ -122,6 +122,41 @@ int rte_eal_pci_init(void);
 struct rte_pci_driver;
 struct rte_pci_device;
 
+/**
+ * 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.
+ *
+ * @param pci_dev
+ *	PCI device to add
+ * @return void
+ */
+void rte_eal_pci_add_device(struct rte_pci_device *pci_dev);
+
+/**
+ * Insert a PCI device in the PCI Bus at a particular location in the device
+ * list. It also updates the PCI Bus reference of the new devices to be
+ * inserted.
+ *
+ * @param exist_pci_dev
+ *	Existing PCI device in PCI Bus
+ * @param new_pci_dev
+ *	PCI device to be added before exist_pci_dev
+ * @return void
+ */
+void rte_eal_pci_insert_device(struct rte_pci_device *exist_pci_dev,
+			       struct rte_pci_device *new_pci_dev);
+
+/**
+ * Remove a PCI device from the PCI Bus. This sets to NULL the bus references
+ * in the PCI device object as well as the generic device object.
+ *
+ * @param pci_device
+ *	PCI device to be removed from PCI Bus
+ * @return void
+ */
+void rte_eal_pci_remove_device(struct rte_pci_device *pci_device);
+
 /**
  * Update a pci device object by asking the kernel for the latest information.
  *

lib/librte_eal/common/include/rte_pci.h

@@ -85,6 +85,7 @@ extern "C" {
 #include <rte_debug.h>
 #include <rte_interrupts.h>
 #include <rte_dev.h>
+#include <rte_bus.h>
 
 TAILQ_HEAD(pci_device_list, rte_pci_device); /**< PCI devices in D-linked Q. */
 TAILQ_HEAD(pci_driver_list, rte_pci_driver); /**< PCI drivers in D-linked Q. */
@@ -111,6 +112,25 @@ const char *pci_get_sysfs_path(void);
 /** Maximum number of PCI resources. */
 #define PCI_MAX_RESOURCE 6
 
+/** Name of PCI Bus */
+#define PCI_BUS_NAME "PCI"
+
+/* Forward declarations */
+struct rte_pci_device;
+struct rte_pci_driver;
+
+/** List of PCI devices */
+TAILQ_HEAD(rte_pci_device_list, rte_pci_device);
+/** List of PCI drivers */
+TAILQ_HEAD(rte_pci_driver_list, rte_pci_driver);
+
+/* PCI Bus iterators */
+#define FOREACH_DEVICE_ON_PCIBUS(p)	\
+		TAILQ_FOREACH(p, &(rte_pci_bus.device_list), next)
+
+#define FOREACH_DRIVER_ON_PCIBUS(p)	\
+		TAILQ_FOREACH(p, &(rte_pci_bus.driver_list), next)
+
 /**
  * A structure describing an ID for a PCI driver. Each driver provides a
  * table of these IDs for each device that it supports.
@@ -206,12 +226,22 @@ typedef int (pci_remove_t)(struct rte_pci_device *);
 struct rte_pci_driver {
 	TAILQ_ENTRY(rte_pci_driver) next;       /**< Next in list. */
 	struct rte_driver driver;               /**< Inherit core driver. */
+	struct rte_pci_bus *bus;                /**< PCI bus reference. */
 	pci_probe_t *probe;                     /**< Device Probe function. */
 	pci_remove_t *remove;                   /**< Device Remove function. */
 	const struct rte_pci_id *id_table;	/**< ID table, NULL terminated. */
 	uint32_t drv_flags;                     /**< Flags contolling handling of device. */
 };
 
+/**
+ * Structure describing the PCI bus
+ */
+struct rte_pci_bus {
+	struct rte_bus bus;               /**< Inherit the generic class */
+	struct rte_pci_device_list device_list;  /**< List of PCI devices */
+	struct rte_pci_driver_list driver_list;  /**< List of PCI drivers */
+};
+
 /** Device needs PCI BAR mapping (done with either IGB_UIO or VFIO) */
 #define RTE_PCI_DRV_NEED_MAPPING 0x0001
 /** Device driver supports link state interrupt */

lib/librte_eal/linuxapp/eal/eal_pci.c

@@ -35,6 +35,7 @@
 #include <dirent.h>
 
 #include <rte_log.h>
+#include <rte_bus.h>
 #include <rte_pci.h>
 #include <rte_eal_memconfig.h>
 #include <rte_malloc.h>
@@ -54,6 +55,8 @@
  * IGB_UIO driver (or doesn't initialize, if the device wasn't bound to it).
  */
 
+extern struct rte_pci_bus rte_pci_bus;
+
 static int
 pci_get_kernel_driver_by_path(const char *filename, char *dri_name)
 {