From: Stephen Hemminger <shemm...@brocade.com>

Some drivers need ability to access PCI config (for example for power
management). This adds an abstraction to do this; only implemented
on Linux, but should be possible on BSD.

Signed-off-by: Stephen Hemminger <stephen at networkplumber.org>
---
 lib/librte_eal/common/include/rte_pci.h         | 29 +++++++++++++++++++++++++
 lib/librte_eal/linuxapp/eal/eal_pci.c           | 15 +++++++++++++
 lib/librte_eal/linuxapp/eal/eal_pci_uio.c       | 10 +++++++++
 lib/librte_eal/linuxapp/eal/rte_eal_version.map |  2 ++
 4 files changed, 56 insertions(+)

diff --git a/lib/librte_eal/common/include/rte_pci.h 
b/lib/librte_eal/common/include/rte_pci.h
index 66ed793..a78081f 100644
--- a/lib/librte_eal/common/include/rte_pci.h
+++ b/lib/librte_eal/common/include/rte_pci.h
@@ -152,6 +152,7 @@ struct rte_pci_device {
        uint16_t max_vfs;                       /**< sriov enable if not zero */
        int numa_node;                          /**< NUMA node connection */
        struct rte_devargs *devargs;            /**< Device user arguments */
+       int config_fd;                          /**< PCI config access */
 };

 /** Any PCI device identifier (vendor, device, ...) */
@@ -298,6 +299,34 @@ void rte_eal_pci_register(struct rte_pci_driver *driver);
  */
 void rte_eal_pci_unregister(struct rte_pci_driver *driver);

+/**
+ * Read PCI config space.
+ *
+ * @param device
+ *   A pointer to a rte_pci_device structure describing the device
+ *   to use
+ * @param buf
+ *   A data buffer where the bytes should be read into
+ * @param size
+ *   The length of the data buffer.
+ */
+int rte_eal_pci_read_config(const struct rte_pci_device *device,
+                           void *buf, size_t len, off_t offset);
+
+/**
+ * Write PCI config space.
+ *
+ * @param device
+ *   A pointer to a rte_pci_device structure describing the device
+ *   to use
+ * @param buf
+ *   A data buffer containing the bytes should be written
+ * @param size
+ *   The length of the data buffer.
+ */
+int rte_eal_pci_write_config(const struct rte_pci_device *device,
+                            const void *buf, size_t len, off_t offset);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c 
b/lib/librte_eal/linuxapp/eal/eal_pci.c
index b5f5410..5bcfffa 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
@@ -233,6 +233,7 @@ pci_scan_one(const char *dirname, uint16_t domain, uint8_t 
bus,
        dev->addr.bus = bus;
        dev->addr.devid = devid;
        dev->addr.function = function;
+       dev->config_fd = -1;

        /* get vendor id */
        snprintf(filename, sizeof(filename), "%s/vendor", dirname);
@@ -592,6 +593,20 @@ rte_eal_pci_probe_one_driver(struct rte_pci_driver *dr, 
struct rte_pci_device *d
        return 1;
 }

+/* Read PCI config space. */
+int rte_eal_pci_read_config(const struct rte_pci_device *device,
+                           void *buf, size_t len, off_t offset)
+{
+       return pread(device->config_fd, buf, len, offset);
+}
+
+/* Write PCI config space. */
+int rte_eal_pci_write_config(const struct rte_pci_device *device,
+                            const void *buf, size_t len, off_t offset)
+{
+       return pwrite(device->config_fd, buf, len, offset);
+}
+
 /* Init the PCI EAL subsystem */
 int
 rte_eal_pci_init(void)
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c 
b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
index e53f06b..0396eaa 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci_uio.c
@@ -213,6 +213,7 @@ pci_get_uio_dev(struct rte_pci_device *dev, char *dstbuf,
        struct dirent *e;
        DIR *dir;
        char dirname[PATH_MAX];
+       char filename[PATH_MAX];

        /* depending on kernel version, uio can be located in uio/uioX
         * or uio:uioX */
@@ -268,6 +269,15 @@ pci_get_uio_dev(struct rte_pci_device *dev, char *dstbuf,
        if (e == NULL)
                return -1;

+       /* Open fd for access to PCI config */
+       snprintf(filename, sizeof(filename), "%s/device/config", dirname);
+       dev->config_fd = open(filename, O_RDWR);
+       if (dev->config_fd < 0) {
+               RTE_LOG(ERR, EAL, "%s(): cannot open %s: %s\n",
+                       __func__, filename, strerror(errno));
+               return -1;
+       }
+
        /* create uio device if we've been asked to */
        if (internal_config.create_uio_dev &&
                        pci_mknod_uio_dev(dstbuf, uio_num) < 0)
diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map 
b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
index d36286e..626689c 100644
--- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
+++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
@@ -40,6 +40,8 @@ DPDK_2.0 {
        rte_eal_pci_probe;
        rte_eal_pci_register;
        rte_eal_pci_unregister;
+       rte_eal_pci_read_config;
+       rte_eal_pci_write_config;
        rte_eal_process_type;
        rte_eal_remote_launch;
        rte_eal_tailq_lookup;
-- 
2.1.4

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