[dpdk-dev] [PATCH v2 2/3] bus/pci: expose sysfs parsing API

[Xiao Wang <xiao.w.wang@intel.com>]

Some existing sysfs parsing functions are helpful for the later vDPA
driver, this patch make them global and expose them to shared lib.

Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>
---
v2:
- Rename function pci_get_kernel_driver_by_path to rte_pci_device_kdriver_name
  to make the API generic cross Linux and BSD, make it as EXPERIMENTAL.
---
 drivers/bus/pci/Makefile                |  2 ++
 drivers/bus/pci/bsd/pci.c               | 14 ++++++++++++++
 drivers/bus/pci/linux/pci.c             | 22 +++++++++++++---------
 drivers/bus/pci/rte_bus_pci.h           | 32 ++++++++++++++++++++++++++++++++
 drivers/bus/pci/rte_bus_pci_version.map |  8 ++++++++
 5 files changed, 69 insertions(+), 9 deletions(-)

diff --git a/drivers/bus/pci/Makefile b/drivers/bus/pci/Makefile
index f3df1c4ce..eb494e0f2 100644
--- a/drivers/bus/pci/Makefile
+++ b/drivers/bus/pci/Makefile
@@ -49,6 +49,8 @@ CFLAGS += -I$(RTE_SDK)/drivers/bus/pci/$(SYSTEM)
 CFLAGS += -I$(RTE_SDK)/lib/librte_eal/common
 CFLAGS += -I$(RTE_SDK)/lib/librte_eal/$(SYSTEM)app/eal
 
+CFLAGS += -DALLOW_EXPERIMENTAL_API
+
 LDLIBS += -lrte_eal -lrte_mbuf -lrte_mempool -lrte_ring
 LDLIBS += -lrte_ethdev -lrte_pci
 
diff --git a/drivers/bus/pci/bsd/pci.c b/drivers/bus/pci/bsd/pci.c
index 655b34b7e..08fbe085e 100644
--- a/drivers/bus/pci/bsd/pci.c
+++ b/drivers/bus/pci/bsd/pci.c
@@ -649,3 +649,17 @@ rte_pci_ioport_unmap(struct rte_pci_ioport *p)
 
 	return ret;
 }
+
+int __rte_experimental
+rte_pci_device_kdriver_name(__rte_unused const struct rte_pci_addr *addr,
+		__rte_unused char *dri_name)
+{
+	return -1;
+}
+
+int __rte_experimental
+rte_pci_parse_sysfs_resource(__rte_unused const char *filename,
+		__rte_unused struct rte_pci_device *dev)
+{
+	return -1;
+}
diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
index abde64119..4ba411c7c 100644
--- a/drivers/bus/pci/linux/pci.c
+++ b/drivers/bus/pci/linux/pci.c
@@ -32,17 +32,22 @@
 
 extern struct rte_pci_bus rte_pci_bus;
 
-static int
-pci_get_kernel_driver_by_path(const char *filename, char *dri_name)
+int __rte_experimental
+rte_pci_device_kdriver_name(const struct rte_pci_addr *addr, char *dri_name)
 {
 	int count;
+	char link[PATH_MAX];
 	char path[PATH_MAX];
 	char *name;
 
-	if (!filename || !dri_name)
+	if (!addr || !dri_name)
 		return -1;
 
-	count = readlink(filename, path, PATH_MAX);
+	snprintf(link, sizeof(link), "%s/" PCI_PRI_FMT "/driver",
+		 rte_pci_get_sysfs_path(), addr->domain, addr->bus, addr->devid,
+		 addr->function);
+
+	count = readlink(link, path, PATH_MAX);
 	if (count >= PATH_MAX)
 		return -1;
 
@@ -168,9 +173,8 @@ pci_parse_one_sysfs_resource(char *line, size_t len, uint64_t *phys_addr,
 	return 0;
 }
 
-/* parse the "resource" sysfs file */
-static int
-pci_parse_sysfs_resource(const char *filename, struct rte_pci_device *dev)
+int __rte_experimental
+rte_pci_parse_sysfs_resource(const char *filename, struct rte_pci_device *dev)
 {
 	FILE *f;
 	char buf[BUFSIZ];
@@ -302,7 +306,7 @@ pci_scan_one(const char *dirname, const struct rte_pci_addr *addr)
 
 	/* parse resources */
 	snprintf(filename, sizeof(filename), "%s/resource", dirname);
-	if (pci_parse_sysfs_resource(filename, dev) < 0) {
+	if (rte_pci_parse_sysfs_resource(filename, dev) < 0) {
 		RTE_LOG(ERR, EAL, "%s(): cannot parse resource\n", __func__);
 		free(dev);
 		return -1;
@@ -310,7 +314,7 @@ pci_scan_one(const char *dirname, const struct rte_pci_addr *addr)
 
 	/* parse driver */
 	snprintf(filename, sizeof(filename), "%s/driver", dirname);
-	ret = pci_get_kernel_driver_by_path(filename, driver);
+	ret = rte_pci_device_kdriver_name(addr, driver);
 	if (ret < 0) {
 		RTE_LOG(ERR, EAL, "Fail to get kernel driver\n");
 		free(dev);
diff --git a/drivers/bus/pci/rte_bus_pci.h b/drivers/bus/pci/rte_bus_pci.h
index 357afb912..98b643356 100644
--- a/drivers/bus/pci/rte_bus_pci.h
+++ b/drivers/bus/pci/rte_bus_pci.h
@@ -304,6 +304,38 @@ void rte_pci_ioport_read(struct rte_pci_ioport *p,
 void rte_pci_ioport_write(struct rte_pci_ioport *p,
 		const void *data, size_t len, off_t offset);
 
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Get the name of kernel driver bound to PCI device.
+ *
+ * @param addr
+ *   The PCI device's location.
+ * @param dri_name
+ *   Output buffer pointer.
+ * @return
+ *   0 on success, negative on error.
+ */
+int __rte_experimental
+rte_pci_device_kdriver_name(const struct rte_pci_addr *addr, char *dri_name);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change, or be removed, without prior notice
+ *
+ * Parse the "resource" sysfs file.
+ *
+ * @param filename
+ *   The PCI resource file path.
+ * @dev
+ *   Pointer of rte_pci_device object, into which the parse result is recorded.
+ * @return
+ *   0 on success, -1 on error, 1 on no driver found.
+ */
+int __rte_experimental
+rte_pci_parse_sysfs_resource(const char *filename, struct rte_pci_device *dev);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/drivers/bus/pci/rte_bus_pci_version.map b/drivers/bus/pci/rte_bus_pci_version.map
index 27e9c4f10..d5576302b 100644
--- a/drivers/bus/pci/rte_bus_pci_version.map
+++ b/drivers/bus/pci/rte_bus_pci_version.map
@@ -16,3 +16,11 @@ DPDK_17.11 {
 
 	local: *;
 };
+
+EXPERIMENTAL {
+	global:
+
+	rte_pci_device_kdriver_name;
+	rte_pci_parse_sysfs_resource;
+
+} DPDK_17.11;
-- 
2.15.1