Imported Upstream version 16.04
[deb_dpdk.git] / lib / librte_eal / linuxapp / eal / eal_pci.c
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
new file mode 100644 (file)
index 0000000..dbf12a8
--- /dev/null
@@ -0,0 +1,762 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   All rights reserved.
+ *
+ *   Redistribution and use in source and binary forms, with or without
+ *   modification, are permitted provided that the following conditions
+ *   are met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in
+ *       the documentation and/or other materials provided with the
+ *       distribution.
+ *     * Neither the name of Intel Corporation nor the names of its
+ *       contributors may be used to endorse or promote products derived
+ *       from this software without specific prior written permission.
+ *
+ *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <string.h>
+#include <dirent.h>
+
+#include <rte_log.h>
+#include <rte_pci.h>
+#include <rte_eal_memconfig.h>
+#include <rte_malloc.h>
+#include <rte_devargs.h>
+#include <rte_memcpy.h>
+
+#include "eal_filesystem.h"
+#include "eal_private.h"
+#include "eal_pci_init.h"
+
+/**
+ * @file
+ * PCI probing under linux
+ *
+ * This code is used to simulate a PCI probe by parsing information in sysfs.
+ * When a registered device matches a driver, it is then initialized with
+ * IGB_UIO driver (or doesn't initialize, if the device wasn't bound to it).
+ */
+
+/* unbind kernel driver for this device */
+int
+pci_unbind_kernel_driver(struct rte_pci_device *dev)
+{
+       int n;
+       FILE *f;
+       char filename[PATH_MAX];
+       char buf[BUFSIZ];
+       struct rte_pci_addr *loc = &dev->addr;
+
+       /* open /sys/bus/pci/devices/AAAA:BB:CC.D/driver */
+       snprintf(filename, sizeof(filename),
+                SYSFS_PCI_DEVICES "/" PCI_PRI_FMT "/driver/unbind",
+                loc->domain, loc->bus, loc->devid, loc->function);
+
+       f = fopen(filename, "w");
+       if (f == NULL) /* device was not bound */
+               return 0;
+
+       n = snprintf(buf, sizeof(buf), PCI_PRI_FMT "\n",
+                    loc->domain, loc->bus, loc->devid, loc->function);
+       if ((n < 0) || (n >= (int)sizeof(buf))) {
+               RTE_LOG(ERR, EAL, "%s(): snprintf failed\n", __func__);
+               goto error;
+       }
+       if (fwrite(buf, n, 1, f) == 0) {
+               RTE_LOG(ERR, EAL, "%s(): could not write to %s\n", __func__,
+                               filename);
+               goto error;
+       }
+
+       fclose(f);
+       return 0;
+
+error:
+       fclose(f);
+       return -1;
+}
+
+static int
+pci_get_kernel_driver_by_path(const char *filename, char *dri_name)
+{
+       int count;
+       char path[PATH_MAX];
+       char *name;
+
+       if (!filename || !dri_name)
+               return -1;
+
+       count = readlink(filename, path, PATH_MAX);
+       if (count >= PATH_MAX)
+               return -1;
+
+       /* For device does not have a driver */
+       if (count < 0)
+               return 1;
+
+       path[count] = '\0';
+
+       name = strrchr(path, '/');
+       if (name) {
+               strncpy(dri_name, name + 1, strlen(name + 1) + 1);
+               return 0;
+       }
+
+       return -1;
+}
+
+/* Map pci device */
+int
+rte_eal_pci_map_device(struct rte_pci_device *dev)
+{
+       int ret = -1;
+
+       /* try mapping the NIC resources using VFIO if it exists */
+       switch (dev->kdrv) {
+       case RTE_KDRV_VFIO:
+#ifdef VFIO_PRESENT
+               if (pci_vfio_is_enabled())
+                       ret = pci_vfio_map_resource(dev);
+#endif
+               break;
+       case RTE_KDRV_IGB_UIO:
+       case RTE_KDRV_UIO_GENERIC:
+               /* map resources for devices that use uio */
+               ret = pci_uio_map_resource(dev);
+               break;
+       default:
+               RTE_LOG(DEBUG, EAL,
+                       "  Not managed by a supported kernel driver, skipped\n");
+               ret = 1;
+               break;
+       }
+
+       return ret;
+}
+
+/* Unmap pci device */
+void
+rte_eal_pci_unmap_device(struct rte_pci_device *dev)
+{
+       /* try unmapping the NIC resources using VFIO if it exists */
+       switch (dev->kdrv) {
+       case RTE_KDRV_VFIO:
+               RTE_LOG(ERR, EAL, "Hotplug doesn't support vfio yet\n");
+               break;
+       case RTE_KDRV_IGB_UIO:
+       case RTE_KDRV_UIO_GENERIC:
+               /* unmap resources for devices that use uio */
+               pci_uio_unmap_resource(dev);
+               break;
+       default:
+               RTE_LOG(DEBUG, EAL,
+                       "  Not managed by a supported kernel driver, skipped\n");
+               break;
+       }
+}
+
+void *
+pci_find_max_end_va(void)
+{
+       const struct rte_memseg *seg = rte_eal_get_physmem_layout();
+       const struct rte_memseg *last = seg;
+       unsigned i = 0;
+
+       for (i = 0; i < RTE_MAX_MEMSEG; i++, seg++) {
+               if (seg->addr == NULL)
+                       break;
+
+               if (seg->addr > last->addr)
+                       last = seg;
+
+       }
+       return RTE_PTR_ADD(last->addr, last->len);
+}
+
+/* parse the "resource" sysfs file */
+static int
+pci_parse_sysfs_resource(const char *filename, struct rte_pci_device *dev)
+{
+       FILE *f;
+       char buf[BUFSIZ];
+       union pci_resource_info {
+               struct {
+                       char *phys_addr;
+                       char *end_addr;
+                       char *flags;
+               };
+               char *ptrs[PCI_RESOURCE_FMT_NVAL];
+       } res_info;
+       int i;
+       uint64_t phys_addr, end_addr, flags;
+
+       f = fopen(filename, "r");
+       if (f == NULL) {
+               RTE_LOG(ERR, EAL, "Cannot open sysfs resource\n");
+               return -1;
+       }
+
+       for (i = 0; i<PCI_MAX_RESOURCE; i++) {
+
+               if (fgets(buf, sizeof(buf), f) == NULL) {
+                       RTE_LOG(ERR, EAL,
+                               "%s(): cannot read resource\n", __func__);
+                       goto error;
+               }
+
+               if (rte_strsplit(buf, sizeof(buf), res_info.ptrs, 3, ' ') != 3) {
+                       RTE_LOG(ERR, EAL,
+                               "%s(): bad resource format\n", __func__);
+                       goto error;
+               }
+               errno = 0;
+               phys_addr = strtoull(res_info.phys_addr, NULL, 16);
+               end_addr = strtoull(res_info.end_addr, NULL, 16);
+               flags = strtoull(res_info.flags, NULL, 16);
+               if (errno != 0) {
+                       RTE_LOG(ERR, EAL,
+                               "%s(): bad resource format\n", __func__);
+                       goto error;
+               }
+
+               if (flags & IORESOURCE_MEM) {
+                       dev->mem_resource[i].phys_addr = phys_addr;
+                       dev->mem_resource[i].len = end_addr - phys_addr + 1;
+                       /* not mapped for now */
+                       dev->mem_resource[i].addr = NULL;
+               }
+       }
+       fclose(f);
+       return 0;
+
+error:
+       fclose(f);
+       return -1;
+}
+
+/* Scan one pci sysfs entry, and fill the devices list from it. */
+static int
+pci_scan_one(const char *dirname, uint16_t domain, uint8_t bus,
+            uint8_t devid, uint8_t function)
+{
+       char filename[PATH_MAX];
+       unsigned long tmp;
+       struct rte_pci_device *dev;
+       char driver[PATH_MAX];
+       int ret;
+
+       dev = malloc(sizeof(*dev));
+       if (dev == NULL)
+               return -1;
+
+       memset(dev, 0, sizeof(*dev));
+       dev->addr.domain = domain;
+       dev->addr.bus = bus;
+       dev->addr.devid = devid;
+       dev->addr.function = function;
+
+       /* get vendor id */
+       snprintf(filename, sizeof(filename), "%s/vendor", dirname);
+       if (eal_parse_sysfs_value(filename, &tmp) < 0) {
+               free(dev);
+               return -1;
+       }
+       dev->id.vendor_id = (uint16_t)tmp;
+
+       /* get device id */
+       snprintf(filename, sizeof(filename), "%s/device", dirname);
+       if (eal_parse_sysfs_value(filename, &tmp) < 0) {
+               free(dev);
+               return -1;
+       }
+       dev->id.device_id = (uint16_t)tmp;
+
+       /* get subsystem_vendor id */
+       snprintf(filename, sizeof(filename), "%s/subsystem_vendor",
+                dirname);
+       if (eal_parse_sysfs_value(filename, &tmp) < 0) {
+               free(dev);
+               return -1;
+       }
+       dev->id.subsystem_vendor_id = (uint16_t)tmp;
+
+       /* get subsystem_device id */
+       snprintf(filename, sizeof(filename), "%s/subsystem_device",
+                dirname);
+       if (eal_parse_sysfs_value(filename, &tmp) < 0) {
+               free(dev);
+               return -1;
+       }
+       dev->id.subsystem_device_id = (uint16_t)tmp;
+
+       /* get max_vfs */
+       dev->max_vfs = 0;
+       snprintf(filename, sizeof(filename), "%s/max_vfs", dirname);
+       if (!access(filename, F_OK) &&
+           eal_parse_sysfs_value(filename, &tmp) == 0)
+               dev->max_vfs = (uint16_t)tmp;
+       else {
+               /* for non igb_uio driver, need kernel version >= 3.8 */
+               snprintf(filename, sizeof(filename),
+                        "%s/sriov_numvfs", dirname);
+               if (!access(filename, F_OK) &&
+                   eal_parse_sysfs_value(filename, &tmp) == 0)
+                       dev->max_vfs = (uint16_t)tmp;
+       }
+
+       /* get numa node */
+       snprintf(filename, sizeof(filename), "%s/numa_node",
+                dirname);
+       if (access(filename, R_OK) != 0) {
+               /* if no NUMA support, set default to 0 */
+               dev->numa_node = 0;
+       } else {
+               if (eal_parse_sysfs_value(filename, &tmp) < 0) {
+                       free(dev);
+                       return -1;
+               }
+               dev->numa_node = tmp;
+       }
+
+       /* parse resources */
+       snprintf(filename, sizeof(filename), "%s/resource", dirname);
+       if (pci_parse_sysfs_resource(filename, dev) < 0) {
+               RTE_LOG(ERR, EAL, "%s(): cannot parse resource\n", __func__);
+               free(dev);
+               return -1;
+       }
+
+       /* parse driver */
+       snprintf(filename, sizeof(filename), "%s/driver", dirname);
+       ret = pci_get_kernel_driver_by_path(filename, driver);
+       if (ret < 0) {
+               RTE_LOG(ERR, EAL, "Fail to get kernel driver\n");
+               free(dev);
+               return -1;
+       }
+
+       if (!ret) {
+               if (!strcmp(driver, "vfio-pci"))
+                       dev->kdrv = RTE_KDRV_VFIO;
+               else if (!strcmp(driver, "igb_uio"))
+                       dev->kdrv = RTE_KDRV_IGB_UIO;
+               else if (!strcmp(driver, "uio_pci_generic"))
+                       dev->kdrv = RTE_KDRV_UIO_GENERIC;
+               else
+                       dev->kdrv = RTE_KDRV_UNKNOWN;
+       } else
+               dev->kdrv = RTE_KDRV_NONE;
+
+       /* device is valid, add in list (sorted) */
+       if (TAILQ_EMPTY(&pci_device_list)) {
+               TAILQ_INSERT_TAIL(&pci_device_list, dev, next);
+       } else {
+               struct rte_pci_device *dev2;
+               int ret;
+
+               TAILQ_FOREACH(dev2, &pci_device_list, next) {
+                       ret = rte_eal_compare_pci_addr(&dev->addr, &dev2->addr);
+                       if (ret > 0)
+                               continue;
+
+                       if (ret < 0) {
+                               TAILQ_INSERT_BEFORE(dev2, dev, next);
+                       } else { /* already registered */
+                               dev2->kdrv = dev->kdrv;
+                               dev2->max_vfs = dev->max_vfs;
+                               memmove(dev2->mem_resource, dev->mem_resource,
+                                       sizeof(dev->mem_resource));
+                               free(dev);
+                       }
+                       return 0;
+               }
+               TAILQ_INSERT_TAIL(&pci_device_list, dev, next);
+       }
+
+       return 0;
+}
+
+/*
+ * split up a pci address into its constituent parts.
+ */
+static int
+parse_pci_addr_format(const char *buf, int bufsize, uint16_t *domain,
+               uint8_t *bus, uint8_t *devid, uint8_t *function)
+{
+       /* first split on ':' */
+       union splitaddr {
+               struct {
+                       char *domain;
+                       char *bus;
+                       char *devid;
+                       char *function;
+               };
+               char *str[PCI_FMT_NVAL]; /* last element-separator is "." not ":" */
+       } splitaddr;
+
+       char *buf_copy = strndup(buf, bufsize);
+       if (buf_copy == NULL)
+               return -1;
+
+       if (rte_strsplit(buf_copy, bufsize, splitaddr.str, PCI_FMT_NVAL, ':')
+                       != PCI_FMT_NVAL - 1)
+               goto error;
+       /* final split is on '.' between devid and function */
+       splitaddr.function = strchr(splitaddr.devid,'.');
+       if (splitaddr.function == NULL)
+               goto error;
+       *splitaddr.function++ = '\0';
+
+       /* now convert to int values */
+       errno = 0;
+       *domain = (uint16_t)strtoul(splitaddr.domain, NULL, 16);
+       *bus = (uint8_t)strtoul(splitaddr.bus, NULL, 16);
+       *devid = (uint8_t)strtoul(splitaddr.devid, NULL, 16);
+       *function = (uint8_t)strtoul(splitaddr.function, NULL, 10);
+       if (errno != 0)
+               goto error;
+
+       free(buf_copy); /* free the copy made with strdup */
+       return 0;
+error:
+       free(buf_copy);
+       return -1;
+}
+
+/*
+ * Scan the content of the PCI bus, and the devices in the devices
+ * list
+ */
+int
+rte_eal_pci_scan(void)
+{
+       struct dirent *e;
+       DIR *dir;
+       char dirname[PATH_MAX];
+       uint16_t domain;
+       uint8_t bus, devid, function;
+
+       dir = opendir(SYSFS_PCI_DEVICES);
+       if (dir == NULL) {
+               RTE_LOG(ERR, EAL, "%s(): opendir failed: %s\n",
+                       __func__, strerror(errno));
+               return -1;
+       }
+
+       while ((e = readdir(dir)) != NULL) {
+               if (e->d_name[0] == '.')
+                       continue;
+
+               if (parse_pci_addr_format(e->d_name, sizeof(e->d_name), &domain,
+                               &bus, &devid, &function) != 0)
+                       continue;
+
+               snprintf(dirname, sizeof(dirname), "%s/%s", SYSFS_PCI_DEVICES,
+                        e->d_name);
+               if (pci_scan_one(dirname, domain, bus, devid, function) < 0)
+                       goto error;
+       }
+       closedir(dir);
+       return 0;
+
+error:
+       closedir(dir);
+       return -1;
+}
+
+#ifdef RTE_PCI_CONFIG
+/*
+ * It is deprecated, all its configurations have been moved into
+ * each PMD respectively.
+ */
+void
+pci_config_space_set(__rte_unused struct rte_pci_device *dev)
+{
+       RTE_LOG(DEBUG, EAL, "Nothing here, as it is deprecated\n");
+}
+#endif
+
+/* Read PCI config space. */
+int rte_eal_pci_read_config(const struct rte_pci_device *device,
+                           void *buf, size_t len, off_t offset)
+{
+       const struct rte_intr_handle *intr_handle = &device->intr_handle;
+
+       switch (intr_handle->type) {
+       case RTE_INTR_HANDLE_UIO:
+       case RTE_INTR_HANDLE_UIO_INTX:
+               return pci_uio_read_config(intr_handle, buf, len, offset);
+
+#ifdef VFIO_PRESENT
+       case RTE_INTR_HANDLE_VFIO_MSIX:
+       case RTE_INTR_HANDLE_VFIO_MSI:
+       case RTE_INTR_HANDLE_VFIO_LEGACY:
+               return pci_vfio_read_config(intr_handle, buf, len, offset);
+#endif
+       default:
+               RTE_LOG(ERR, EAL,
+                       "Unknown handle type of fd %d\n",
+                                       intr_handle->fd);
+               return -1;
+       }
+}
+
+/* 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)
+{
+       const struct rte_intr_handle *intr_handle = &device->intr_handle;
+
+       switch (intr_handle->type) {
+       case RTE_INTR_HANDLE_UIO:
+       case RTE_INTR_HANDLE_UIO_INTX:
+               return pci_uio_write_config(intr_handle, buf, len, offset);
+
+#ifdef VFIO_PRESENT
+       case RTE_INTR_HANDLE_VFIO_MSIX:
+       case RTE_INTR_HANDLE_VFIO_MSI:
+       case RTE_INTR_HANDLE_VFIO_LEGACY:
+               return pci_vfio_write_config(intr_handle, buf, len, offset);
+#endif
+       default:
+               RTE_LOG(ERR, EAL,
+                       "Unknown handle type of fd %d\n",
+                                       intr_handle->fd);
+               return -1;
+       }
+}
+
+#if defined(RTE_ARCH_X86)
+static int
+pci_ioport_map(struct rte_pci_device *dev, int bar __rte_unused,
+              struct rte_pci_ioport *p)
+{
+       uint16_t start, end;
+       FILE *fp;
+       char *line = NULL;
+       char pci_id[16];
+       int found = 0;
+       size_t linesz;
+
+       snprintf(pci_id, sizeof(pci_id), PCI_PRI_FMT,
+                dev->addr.domain, dev->addr.bus,
+                dev->addr.devid, dev->addr.function);
+
+       fp = fopen("/proc/ioports", "r");
+       if (fp == NULL) {
+               RTE_LOG(ERR, EAL, "%s(): can't open ioports\n", __func__);
+               return -1;
+       }
+
+       while (getdelim(&line, &linesz, '\n', fp) > 0) {
+               char *ptr = line;
+               char *left;
+               int n;
+
+               n = strcspn(ptr, ":");
+               ptr[n] = 0;
+               left = &ptr[n + 1];
+
+               while (*left && isspace(*left))
+                       left++;
+
+               if (!strncmp(left, pci_id, strlen(pci_id))) {
+                       found = 1;
+
+                       while (*ptr && isspace(*ptr))
+                               ptr++;
+
+                       sscanf(ptr, "%04hx-%04hx", &start, &end);
+
+                       break;
+               }
+       }
+
+       free(line);
+       fclose(fp);
+
+       if (!found)
+               return -1;
+
+       dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
+       p->base = start;
+       RTE_LOG(DEBUG, EAL, "PCI Port IO found start=0x%x\n", start);
+
+       return 0;
+}
+#endif
+
+int
+rte_eal_pci_ioport_map(struct rte_pci_device *dev, int bar,
+                      struct rte_pci_ioport *p)
+{
+       int ret = -1;
+
+       switch (dev->kdrv) {
+#ifdef VFIO_PRESENT
+       case RTE_KDRV_VFIO:
+               if (pci_vfio_is_enabled())
+                       ret = pci_vfio_ioport_map(dev, bar, p);
+               break;
+#endif
+       case RTE_KDRV_IGB_UIO:
+               ret = pci_uio_ioport_map(dev, bar, p);
+               break;
+       case RTE_KDRV_UIO_GENERIC:
+#if defined(RTE_ARCH_X86)
+               ret = pci_ioport_map(dev, bar, p);
+#else
+               ret = pci_uio_ioport_map(dev, bar, p);
+#endif
+               break;
+       case RTE_KDRV_NONE:
+#if defined(RTE_ARCH_X86)
+               ret = pci_ioport_map(dev, bar, p);
+#endif
+               break;
+       default:
+               break;
+       }
+
+       if (!ret)
+               p->dev = dev;
+
+       return ret;
+}
+
+void
+rte_eal_pci_ioport_read(struct rte_pci_ioport *p,
+                       void *data, size_t len, off_t offset)
+{
+       switch (p->dev->kdrv) {
+#ifdef VFIO_PRESENT
+       case RTE_KDRV_VFIO:
+               pci_vfio_ioport_read(p, data, len, offset);
+               break;
+#endif
+       case RTE_KDRV_IGB_UIO:
+               pci_uio_ioport_read(p, data, len, offset);
+               break;
+       case RTE_KDRV_UIO_GENERIC:
+               pci_uio_ioport_read(p, data, len, offset);
+               break;
+       case RTE_KDRV_NONE:
+#if defined(RTE_ARCH_X86)
+               pci_uio_ioport_read(p, data, len, offset);
+#endif
+               break;
+       default:
+               break;
+       }
+}
+
+void
+rte_eal_pci_ioport_write(struct rte_pci_ioport *p,
+                        const void *data, size_t len, off_t offset)
+{
+       switch (p->dev->kdrv) {
+#ifdef VFIO_PRESENT
+       case RTE_KDRV_VFIO:
+               pci_vfio_ioport_write(p, data, len, offset);
+               break;
+#endif
+       case RTE_KDRV_IGB_UIO:
+               pci_uio_ioport_write(p, data, len, offset);
+               break;
+       case RTE_KDRV_UIO_GENERIC:
+               pci_uio_ioport_write(p, data, len, offset);
+               break;
+       case RTE_KDRV_NONE:
+#if defined(RTE_ARCH_X86)
+               pci_uio_ioport_write(p, data, len, offset);
+#endif
+               break;
+       default:
+               break;
+       }
+}
+
+int
+rte_eal_pci_ioport_unmap(struct rte_pci_ioport *p)
+{
+       int ret = -1;
+
+       switch (p->dev->kdrv) {
+#ifdef VFIO_PRESENT
+       case RTE_KDRV_VFIO:
+               if (pci_vfio_is_enabled())
+                       ret = pci_vfio_ioport_unmap(p);
+               break;
+#endif
+       case RTE_KDRV_IGB_UIO:
+               ret = pci_uio_ioport_unmap(p);
+               break;
+       case RTE_KDRV_UIO_GENERIC:
+#if defined(RTE_ARCH_X86)
+               ret = 0;
+#else
+               ret = pci_uio_ioport_unmap(p);
+#endif
+               break;
+       case RTE_KDRV_NONE:
+#if defined(RTE_ARCH_X86)
+               ret = 0;
+#endif
+               break;
+       default:
+               break;
+       }
+
+       return ret;
+}
+
+/* Init the PCI EAL subsystem */
+int
+rte_eal_pci_init(void)
+{
+       TAILQ_INIT(&pci_driver_list);
+       TAILQ_INIT(&pci_device_list);
+
+       /* for debug purposes, PCI can be disabled */
+       if (internal_config.no_pci)
+               return 0;
+
+       if (rte_eal_pci_scan() < 0) {
+               RTE_LOG(ERR, EAL, "%s(): Cannot scan PCI bus\n", __func__);
+               return -1;
+       }
+#ifdef VFIO_PRESENT
+       pci_vfio_enable();
+
+       if (pci_vfio_is_enabled()) {
+
+               /* if we are primary process, create a thread to communicate with
+                * secondary processes. the thread will use a socket to wait for
+                * requests from secondary process to send open file descriptors,
+                * because VFIO does not allow multiple open descriptors on a group or
+                * VFIO container.
+                */
+               if (internal_config.process_type == RTE_PROC_PRIMARY &&
+                               pci_vfio_mp_sync_setup() < 0)
+                       return -1;
+       }
+#endif
+       return 0;
+}