[dpdk-dev] [PATCH v6 8/8] eal: enable hotplugging of devices on bus

Shreyansh Jain shreyansh.jain at nxp.com
Tue Jan 17 08:24:49 CET 2017


On Monday 16 January 2017 09:08 PM, Shreyansh Jain wrote:
> Given a bus, attach and detach callbacks allow the implementation to
> handles calls from EAL for attaching or detaching a named device.
>
> Signed-off-by: Shreyansh Jain <shreyansh.jain at nxp.com>
> ---
>  lib/librte_eal/bsdapp/eal/eal_pci.c     |  2 +
>  lib/librte_eal/common/eal_common_dev.c  | 56 +++++++++++++++++-----
>  lib/librte_eal/common/eal_common_pci.c  | 82 +++++++++++++++++++++++++++++++--
>  lib/librte_eal/common/include/rte_bus.h | 35 ++++++++++++++
>  lib/librte_eal/common/include/rte_pci.h | 58 +++++++++++++++++++----
>  lib/librte_eal/linuxapp/eal/eal_pci.c   |  2 +
>  6 files changed, 212 insertions(+), 23 deletions(-)
>
> diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c b/lib/librte_eal/bsdapp/eal/eal_pci.c
> index 48bfe24..17a04d9 100644
> --- a/lib/librte_eal/bsdapp/eal/eal_pci.c
> +++ b/lib/librte_eal/bsdapp/eal/eal_pci.c
> @@ -678,6 +678,8 @@ struct rte_pci_bus rte_pci_bus = {
>  	.bus = {
>  		.scan = rte_eal_pci_scan,
>  		.probe = rte_eal_pci_probe,
> +		.attach = rte_eal_pci_attach,
> +		.detach = rte_eal_pci_detach,
>  	},
>  	.device_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.device_list),
>  	.driver_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.driver_list),
> diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
> index 4f3b493..b363fa9 100644
> --- a/lib/librte_eal/common/eal_common_dev.c
> +++ b/lib/librte_eal/common/eal_common_dev.c
> @@ -38,6 +38,7 @@
>  #include <sys/queue.h>
>
>  #include <rte_dev.h>
> +#include <rte_bus.h>
>  #include <rte_devargs.h>
>  #include <rte_debug.h>
>  #include <rte_devargs.h>
> @@ -106,23 +107,37 @@ rte_eal_dev_init(void)
>
>  int rte_eal_dev_attach(const char *name, const char *devargs)
>  {
> -	struct rte_pci_addr addr;
> +	int ret = 1;
> +	struct rte_bus *bus;
>
>  	if (name == NULL || devargs == NULL) {
>  		RTE_LOG(ERR, EAL, "Invalid device or arguments provided\n");
>  		return -EINVAL;
>  	}
>
> -	if (eal_parse_pci_DomBDF(name, &addr) == 0) {
> -		if (rte_eal_pci_probe_one(&addr) < 0)
> +	FOREACH_BUS(bus) {
> +		if (!bus->attach) {
> +			RTE_LOG(DEBUG, EAL, "Bus (%s) doesn't implement"
> +				" attach.\n", bus->name);
> +			continue;
> +		}
> +		ret = bus->attach(bus, name);
> +		if (!ret) /* device successfully attached */
> +			return ret;
> +		if (ret > 0) /* device not found on bus */
> +			continue;
> +		else
>  			goto err;
> +	}
>
> -	} else {
> -		if (rte_eal_vdev_init(name, devargs))
> +	if (ret > 0) {
> +		/* In case the device was not found on any bus, search VDEV */
> +		ret = rte_eal_vdev_init(name, devargs);
> +		if (ret)
>  			goto err;
>  	}
>
> -	return 0;
> +	return ret;
>
>  err:
>  	RTE_LOG(ERR, EAL, "Driver cannot attach the device (%s)\n", name);
> @@ -131,21 +146,38 @@ int rte_eal_dev_attach(const char *name, const char *devargs)
>
>  int rte_eal_dev_detach(const char *name)
>  {
> -	struct rte_pci_addr addr;
> +	int ret = 1;
> +	struct rte_bus *bus;
>
>  	if (name == NULL) {
>  		RTE_LOG(ERR, EAL, "Invalid device provided.\n");
>  		return -EINVAL;
>  	}
>
> -	if (eal_parse_pci_DomBDF(name, &addr) == 0) {
> -		if (rte_eal_pci_detach(&addr) < 0)
> +	FOREACH_BUS(bus) {
> +		if (!bus->detach) {
> +			RTE_LOG(DEBUG, EAL, "Bus (%s) doesn't implement"
> +				" detach.\n", bus->name);
> +			continue;
> +		}
> +
> +		ret = bus->detach(bus, name);
> +		if (!ret) /* device successfully detached */
> +			return ret;
> +		if (ret > 0) /* device not found on the bus */
> +			continue;
> +		else
>  			goto err;
> -	} else {
> -		if (rte_eal_vdev_uninit(name))
> +	}
> +
> +	if (ret > 0) {
> +		/* In case the device was not found on any bus, search VDEV */
> +		ret = rte_eal_vdev_uninit(name);
> +		if (ret)
>  			goto err;
>  	}
> -	return 0;
> +
> +	return ret;
>
>  err:
>  	RTE_LOG(ERR, EAL, "Driver cannot detach the device (%s)\n", name);
> diff --git a/lib/librte_eal/common/eal_common_pci.c b/lib/librte_eal/common/eal_common_pci.c
> index 1d283d2..1c205bd 100644
> --- a/lib/librte_eal/common/eal_common_pci.c
> +++ b/lib/librte_eal/common/eal_common_pci.c
> @@ -389,19 +389,95 @@ rte_eal_pci_probe_one(const struct rte_pci_addr *addr)
>  }
>
>  /*
> + * Attach device specific by its name
> + */
> +int
> +rte_eal_pci_attach(struct rte_bus *bus __rte_unused, const char *device_name)
> +{
> +	struct rte_pci_device *dev = NULL;
> +	struct rte_pci_driver *drv = NULL;
> +	struct rte_pci_addr addr;
> +	int ret = -1;
> +
> +	if (!device_name)
> +		return -1;
> +
> +	memset(&addr, 0, sizeof(addr));
> +	if (eal_parse_pci_DomBDF(device_name, &addr) == 0) {
> +		/* Device doesn't match PCI BDF naming format */
> +		return -1;
> +	}
> +
> +	FOREACH_DEVICE_ON_PCIBUS(dev) {
> +		if (rte_eal_compare_pci_addr(&dev->addr, &addr))
> +			continue;
> +
> +		FOREACH_DRIVER_ON_PCIBUS(drv) {
> +			ret = rte_pci_match(drv, dev);
> +			if (ret) {
> +				/* Match of device and driver failed */
> +				RTE_LOG(DEBUG, EAL, "Driver (%s) doesn't match"
> +					" the device (%s)\n", drv->driver.name,
> +					device_name);
> +				continue;
> +			}
> +
> +			RTE_LOG(INFO, EAL, "  probe driver: %x:%x %s\n",
> +				dev->id.vendor_id, dev->id.device_id,
> +				drv->driver.name);
> +
> +			if (drv->drv_flags & RTE_PCI_DRV_NEED_MAPPING) {
> +				/* map resources for devices that use
> +				 * igb_uio
> +				 */
> +				ret = rte_eal_pci_map_device(dev);
> +				if (ret != 0)
> +					goto err_return;
> +			}
> +
> +			/* reference driver structure */
> +			dev->driver = drv;
> +
> +			/* call the driver probe() function */
> +			ret = drv->probe(drv, dev);
> +			if (ret) {
> +				dev->driver = NULL;
> +				if (drv->drv_flags & RTE_PCI_DRV_NEED_MAPPING)
> +					rte_eal_pci_unmap_device(dev);
> +			}
> +		}
> +	}
> +
> +	return ret;
> +
> +err_return:
> +	RTE_LOG(WARNING, EAL, "Requested device " PCI_PRI_FMT
> +			" cannot be used\n", dev->addr.domain, dev->addr.bus,
> +			dev->addr.devid, dev->addr.function);
> +	return -1;
> +}
> +
> +/*
>   * Detach device specified by its pci address.
>   */
>  int
> -rte_eal_pci_detach(const struct rte_pci_addr *addr)
> +rte_eal_pci_detach(struct rte_bus *bus __rte_unused, const char *device_name)
>  {
>  	struct rte_pci_device *dev = NULL;
> +	struct rte_pci_addr addr;
>  	int ret = 0;
>
> -	if (addr == NULL)
> +	if (!device_name)
>  		return -1;
>
> +	memset(&addr, 0, sizeof(addr));
> +	if (eal_parse_pci_DomBDF(device_name, &addr) == 0) {
> +		/* Device doesn't match PCI BDF naming format */
> +		return -1;
> +	}
> +
>  	FOREACH_DEVICE_ON_PCIBUS(dev) {
> -		if (rte_eal_compare_pci_addr(&dev->addr, addr))
> +		if (rte_eal_compare_pci_addr(&dev->addr, &addr))
>  			continue;
>
>  		ret = pci_detach_all_drivers(dev);
> diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
> index f1d4c2c..5b7ae0c 100644
> --- a/lib/librte_eal/common/include/rte_bus.h
> +++ b/lib/librte_eal/common/include/rte_bus.h
> @@ -59,6 +59,8 @@ TAILQ_HEAD(rte_bus_list, rte_bus);
>  /* Bus list exposed */
>  extern struct rte_bus_list rte_bus_list;
>
> +#define FOREACH_BUS(bus_p)	TAILQ_FOREACH(bus_p, &rte_bus_list, next)
> +
>  /**
>   * Bus specific scan for devices attached on the bus.
>   * For each bus object, the scan would be reponsible for finding devices and
> @@ -94,6 +96,37 @@ typedef int (*rte_bus_scan_t)(void);
>  typedef int (*rte_bus_probe_t)(void);
>
>  /**
> + * Attach a device to a bus, assuming it is 'connected' to the bus.
> + * A bus is responsible for scanning for devices. Attaching a new device is
> + * for reenabling the device after being detached/removed.
> + *
> + * @param bus
> + *	Generic bus object which was registered with EAL
> + * @param device_name
> + *	Name of the device to attach.
> + *
> + * @return
> + *	0 for successful attach
> + *	!0 for unsuccessful attach (or incorrect device name)
> + */
> +typedef int (*rte_bus_attach_t)(struct rte_bus *bus, const char *device_name);
> +
> +/**
> + * Detach a named device from a bus. Implementation would check the existence
> + * of device on the bus and detach it.
> + *
> + * @param bus
> + *	Generic bus object which was registered with EAL
> + * @param device_name
> + *	Name of the device to detach
> + *
> + * @return
> + *	0 for successful detaching
> + *	!0 if device not found or can't detach
> + */
> +typedef int (*rte_bus_detach_t)(struct rte_bus *bus, const char *device_name);
> +
> +/**
>   * A structure describing a generic bus.
>   */
>  struct rte_bus {
> @@ -101,6 +134,8 @@ struct rte_bus {
>  	const char *name;            /**< Name of the bus */
>  	rte_bus_scan_t scan;         /**< Scan for devices attached to bus */
>  	rte_bus_probe_t probe;       /**< Probe devices on bus */
> +	rte_bus_attach_t attach;     /**< Attach a named device */
> +	rte_bus_detach_t detach;     /**< Detach a named device */
>  };
>
>  /**
> diff --git a/lib/librte_eal/common/include/rte_pci.h b/lib/librte_eal/common/include/rte_pci.h
> index 5f8d679..6369584 100644
> --- a/lib/librte_eal/common/include/rte_pci.h
> +++ b/lib/librte_eal/common/include/rte_pci.h
> @@ -421,6 +421,40 @@ int
>  rte_eal_pci_probe(void);
>
>  /**
> + * Search and attach a PCI device to PCI Bus
> + * Implements rte_bus->attach
> + *
> + * @param bus
> + *	Generic bus object representing PCI bus
> + * @param device_name
> + *	Name of the device to search and attach
> + *
> + * @return
> + *	0 for successful removal of device
> + *	>0 if device not found on bus
> + *	<0 in case of error in removal.
> + */
> +int
> +rte_eal_pci_attach(struct rte_bus *bus, const char *device_name);

The first argument, rte_bus, is not required. I will remove this in v7.

> +
> +/**
> + * Search and detach a PCI device from PCI Bus
> + * Implements rte_bus->detach
> + *
> + * @param bus
> + *	Generic bus object representing PCI bus
> + * @param device_name
> + *	Name of the device to search and detach
> + *
> + * @return
> + *	0 for successful detaching of device
> + *	>0 if device not found on bus
> + *	<0 in case of error in removal.
> + */
> +int
> +rte_eal_pci_detach(struct rte_bus *bus, const char *device_name);

Same as above, rte_bus argument is not required and will be removed in v7.

> +
> +/**
>   * Map the PCI device resources in user space virtual memory address
>   *
>   * Note that driver should not call this function when flag
> @@ -494,19 +528,27 @@ void pci_unmap_resource(void *requested_addr, size_t size);
>  int rte_eal_pci_probe_one(const struct rte_pci_addr *addr);
>
>  /**
> - * Close the single PCI device.
> - *
> - * Scan the content of the PCI bus, and find the pci device specified by pci
> - * address, then call the remove() function for registered driver that has a
> - * matching entry in its id_table for discovered device.
> + * Attach a PCI device on PCI Bus
> + * @param bus
> + *	Generic Bus object for PCI Bus. If passed NULL, PCI bus is extracted
> + *	using Bus APIs.
> + * @param device_name
> + *	Device Name, which would be converted into BDF.
> + */
> +int rte_eal_pci_attach(struct rte_bus *bus, const char *device_name);
> +
> +/**
> + * Detach a single PCI device.
>   *
> - * @param addr
> - *	The PCI Bus-Device-Function address to close.
> + * @param bus
> + *	Generic bus object for PCI bus.
> + * @param device_name
> + *	Device Name, which would be converted into BDF.
>   * @return
>   *   - 0 on success.
>   *   - Negative on error.
>   */
> -int rte_eal_pci_detach(const struct rte_pci_addr *addr);
> +int rte_eal_pci_detach(struct rte_bus *bus, const char *device_name);
>
>  /**
>   * Dump the content of the PCI bus.
> diff --git a/lib/librte_eal/linuxapp/eal/eal_pci.c b/lib/librte_eal/linuxapp/eal/eal_pci.c
> index 50ad9f7..8084996 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_pci.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_pci.c
> @@ -716,6 +716,8 @@ struct rte_pci_bus rte_pci_bus = {
>  	.bus = {
>  		.scan = rte_eal_pci_scan,
>  		.probe = rte_eal_pci_probe,
> +		.attach = rte_eal_pci_attach,
> +		.detach = rte_eal_pci_detach,
>  	},
>  	.device_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.device_list),
>  	.driver_list = TAILQ_HEAD_INITIALIZER(rte_pci_bus.driver_list),
>



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