[dpdk-dev] [PATCH 2/2] pci: add option --create-uio-dev to run without hotplug
Olivier Matz
olivier.matz at 6wind.com
Fri Jan 24 16:31:27 CET 2014
When the user specifies --create-uio-dev in dpdk eal start options, the
DPDK will create the /dev/uioX instead of waiting that a program does it
(which is usually hotplug).
This option is useful in embedded environments where there is no hotplug
to do the work.
Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
---
lib/librte_eal/linuxapp/eal/eal.c | 6 +++
lib/librte_eal/linuxapp/eal/eal_pci.c | 47 +++++++++++++++++++++-
.../linuxapp/eal/include/eal_internal_cfg.h | 1 +
3 files changed, 53 insertions(+), 1 deletion(-)
diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
index bd20331..9168b3f 100644
--- a/lib/librte_eal/linuxapp/eal/eal.c
+++ b/lib/librte_eal/linuxapp/eal/eal.c
@@ -94,6 +94,7 @@
#define OPT_SOCKET_MEM "socket-mem"
#define OPT_USE_DEVICE "use-device"
#define OPT_SYSLOG "syslog"
+#define OPT_CREATE_UIO_DEV "create-uio-dev"
#define RTE_EAL_BLACKLIST_SIZE 0x100
@@ -357,6 +358,7 @@ eal_usage(const char *prgname)
" --"OPT_NO_PCI" : disable pci\n"
" --"OPT_NO_HPET" : disable hpet\n"
" --"OPT_NO_SHCONF": no shared config (mmap'd files)\n"
+ " --"OPT_CREATE_UIO_DEV": create /dev/uioX (usually done by hotplug)\n"
"\n",
prgname);
/* Allow the application to print its usage message too if hook is set */
@@ -608,6 +610,7 @@ eal_parse_args(int argc, char **argv)
{OPT_SOCKET_MEM, 1, 0, 0},
{OPT_USE_DEVICE, 1, 0, 0},
{OPT_SYSLOG, 1, NULL, 0},
+ {OPT_CREATE_UIO_DEV, 1, NULL, 0},
{0, 0, 0, 0}
};
struct shared_driver *solib;
@@ -747,6 +750,9 @@ eal_parse_args(int argc, char **argv)
return -1;
}
}
+ else if (!strcmp(lgopts[option_index].name, OPT_CREATE_UIO_DEV)) {
+ internal_config.create_uio_dev = 1;
+ }
break;
default:
diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
index 1039777..af5a8b9 100644
--- a/lib/librte_eal/linuxapp/eal/eal_pci.c
+++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
@@ -460,6 +460,47 @@ pci_uio_map_secondary(struct rte_pci_device *dev)
return -1;
}
+static int pci_mknod_uio_dev(const char *sysfs_uio_path, unsigned uio_num)
+{
+ FILE *f;
+ char filename[PATH_MAX];
+ int ret;
+ unsigned major, minor;
+ dev_t dev;
+
+ /* get the name of the sysfs file that contains the major and minor
+ * of the uio device and read its content */
+ rte_snprintf(filename, sizeof(filename), "%s/dev", sysfs_uio_path);
+
+ f = fopen(filename, "r");
+ if (f == NULL) {
+ RTE_LOG(ERR, EAL, "%s(): cannot open sysfs to get major:minor\n",
+ __func__);
+ return -1;
+ }
+
+ ret = fscanf(f, "%d:%d", &major, &minor);
+ if (ret != 2) {
+ RTE_LOG(ERR, EAL, "%s(): cannot parse sysfs to get major:minor\n",
+ __func__);
+ fclose(f);
+ return -1;
+ }
+ fclose(f);
+
+ /* create the char device "mknod /dev/uioX c major minor" */
+ rte_snprintf(filename, sizeof(filename), "/dev/uio%u", uio_num);
+ dev = makedev(major, minor);
+ ret = mknod(filename, S_IFCHR | S_IRUSR | S_IWUSR, dev);
+ if (f == NULL) {
+ RTE_LOG(ERR, EAL, "%s(): mknod() failed %s\n",
+ __func__, strerror(errno));
+ return -1;
+ }
+
+ return ret;
+}
+
/*
* Return the uioX char device used for a pci device. On success, return
* the UIO number and fill dstbuf string with the path of the device in
@@ -529,7 +570,11 @@ static int pci_get_uio_dev(struct rte_pci_device *dev, char *dstbuf,
if (e == NULL)
return -1;
- return 0;
+ /* create uio device if we've been asked to */
+ if (internal_config.create_uio_dev && pci_mknod_uio_dev(dstbuf, uio_num) < 0)
+ RTE_LOG(WARNING, EAL, "Cannot create /dev/uio%u\n", uio_num);
+
+ return uio_num;
}
/* map the PCI resource of a PCI device in virtual memory */
diff --git a/lib/librte_eal/linuxapp/eal/include/eal_internal_cfg.h b/lib/librte_eal/linuxapp/eal/include/eal_internal_cfg.h
index 45ec058..649bd2b 100644
--- a/lib/librte_eal/linuxapp/eal/include/eal_internal_cfg.h
+++ b/lib/librte_eal/linuxapp/eal/include/eal_internal_cfg.h
@@ -68,6 +68,7 @@ struct internal_config {
volatile unsigned vmware_tsc_map; /**< true to use VMware TSC mapping
* instead of native TSC */
volatile unsigned no_shconf; /**< true if there is no shared config */
+ volatile unsigned create_uio_dev; /**< true to create /dev/uioX devices */
volatile enum rte_proc_type_t process_type; /**< multi-process proc type */
/** true to try allocating memory on specific sockets */
volatile unsigned force_sockets;
--
1.8.4.rc3
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