[dpdk-dev] [PATCH v7 11/21] eal/soc: implement probing of drivers

[Jianbo Liu]

On 28 October 2016 at 20:26, Shreyansh Jain <shreyansh.jain at nxp.com> wrote:
> Each SoC PMD registers a set of callback for scanning its own bus/infra and
> matching devices to drivers when probe is called.
> This patch introduces the infra for calls to SoC scan on rte_eal_soc_init()
> and match on rte_eal_soc_probe().
>
> Patch also adds test case for scan and probe.
>
> Signed-off-by: Jan Viktorin <viktorin at rehivetech.com>
> Signed-off-by: Shreyansh Jain <shreyansh.jain at nxp.com>
> Signed-off-by: Hemant Agrawal <hemant.agrawal at nxp.com>
> --
> v4:
>  - Update test_soc for descriptive test function names
>  - Comments over test functions
>  - devinit and devuninint --> probe/remove
>  - RTE_VERIFY at some places
> ---
>  app/test/test_soc.c                             | 205 ++++++++++++++++++++++-
>  lib/librte_eal/bsdapp/eal/rte_eal_version.map   |   4 +
>  lib/librte_eal/common/eal_common_soc.c          | 213 +++++++++++++++++++++++-
>  lib/librte_eal/common/include/rte_soc.h         |  75 ++++++++-
>  lib/librte_eal/linuxapp/eal/eal.c               |   5 +
>  lib/librte_eal/linuxapp/eal/eal_soc.c           |  21 ++-
>  lib/librte_eal/linuxapp/eal/rte_eal_version.map |   4 +
>  7 files changed, 519 insertions(+), 8 deletions(-)
>
.....

>  /**
> + * SoC device scan callback, called from rte_eal_soc_init.
> + * For various SoC, the bus on which devices are attached maynot be compliant
> + * to a standard platform (or platform bus itself). In which case, extra
> + * steps are implemented by PMD to scan over the bus and add devices to SoC
> + * device list.
> + */
> +typedef void (soc_scan_t)(void);

I'm still not sure about the purpose of soc_scan, and how to use it.
If it's for each driver, it should at least struct rte_soc_driver * as
its parameter.
If it's for each bus, why it is in rte_soc_driver?
I know you will implement bus driver in the future, but we need to
make it clear for current simplified implementation.

> +
> +/**
> + * Custom device<=>driver match callback for SoC
> + * Unlike PCI, SoC devices don't have a fixed definition of device
> + * identification. PMDs can implement a specific matching function in which
> + * driver and device objects are provided to perform custom match.
> + */
> +typedef int (soc_match_t)(struct rte_soc_driver *, struct rte_soc_device *);
> +
> +/**
>   * A structure describing a SoC driver.
>   */
>  struct rte_soc_driver {
> @@ -104,6 +120,8 @@ struct rte_soc_driver {
>         struct rte_driver driver;          /**< Inherit core driver. */
>         soc_probe_t *probe;                /**< Device probe */
>         soc_remove_t *remove;              /**< Device remove */
> +       soc_scan_t *scan_fn;               /**< Callback for scanning SoC bus*/
> +       soc_match_t *match_fn;             /**< Callback to match dev<->drv */
>         const struct rte_soc_id *id_table; /**< ID table, NULL terminated */
>  };
>
> @@ -146,12 +164,63 @@ rte_eal_compare_soc_addr(const struct rte_soc_addr *a0,
>  }
>
>  /**
> + * Default function for matching the Soc driver with device. Each driver can
> + * either use this function or define their own soc matching function.
> + * This function relies on the compatible string extracted from sysfs. But,
> + * a SoC might have different way of identifying its devices. Such SoC can
> + * override match_fn.
> + *
> + * @return
> + *      0 on success
> + *     -1 when no match found
> +  */
> +int
> +rte_eal_soc_match_compat(struct rte_soc_driver *drv,
> +                        struct rte_soc_device *dev);
> +
> +/**
> + * Probe SoC devices for registered drivers.
> + *
> + * @return
> + *     0 on success
> + *     !0 in case of any failure in probe
> + */
> +int rte_eal_soc_probe(void);
> +
> +/**
> + * Probe the single SoC device.
> + */
> +int rte_eal_soc_probe_one(const struct rte_soc_addr *addr);
> +
> +/**
> + * Close the single SoC device.
> + *
> + * Scan the SoC devices and find the SoC device specified by the SoC
> + * address, then call the remove() function for registered driver
> + * that has a matching entry in its id_table for discovered device.
> + *
> + * @param addr
> + *     The SoC address to close.
> + * @return
> + *   - 0 on success.
> + *   - Negative on error.
> + */
> +int rte_eal_soc_detach(const struct rte_soc_addr *addr);
> +
> +/**
>   * Dump discovered SoC devices.
> + *
> + * @param f
> + *     File to dump device info in.
>   */
>  void rte_eal_soc_dump(FILE *f);
>
>  /**
>   * Register a SoC driver.
> + *
> + * @param driver
> + *     Object for SoC driver to register
> + * @return void
>   */
>  void rte_eal_soc_register(struct rte_soc_driver *driver);
>
> @@ -167,6 +236,10 @@ RTE_PMD_EXPORT_NAME(nm, __COUNTER__)
>
>  /**
>   * Unregister a SoC driver.
> + *
> + * @param driver
> + *     Object for SoC driver to unregister
> + * @return void
>   */
>  void rte_eal_soc_unregister(struct rte_soc_driver *driver);
>
> diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c
> index 098ba02..bd775f3 100644
> --- a/lib/librte_eal/linuxapp/eal/eal.c
> +++ b/lib/librte_eal/linuxapp/eal/eal.c
> @@ -70,6 +70,7 @@
>  #include <rte_cpuflags.h>
>  #include <rte_interrupts.h>
>  #include <rte_pci.h>
> +#include <rte_soc.h>
>  #include <rte_dev.h>
>  #include <rte_devargs.h>
>  #include <rte_common.h>
> @@ -890,6 +891,10 @@ rte_eal_init(int argc, char **argv)
>         if (rte_eal_pci_probe())
>                 rte_panic("Cannot probe PCI\n");
>
> +       /* Probe & Initialize SoC devices */
> +       if (rte_eal_soc_probe())
> +               rte_panic("Cannot probe SoC\n");
> +
>         rte_eal_mcfg_complete();
>
>         return fctret;
> diff --git a/lib/librte_eal/linuxapp/eal/eal_soc.c b/lib/librte_eal/linuxapp/eal/eal_soc.c
> index 04848b9..3929a76 100644
> --- a/lib/librte_eal/linuxapp/eal/eal_soc.c
> +++ b/lib/librte_eal/linuxapp/eal/eal_soc.c
> @@ -44,13 +44,28 @@
>  #include <rte_log.h>
>  #include <rte_soc.h>
>
> -#include "eal_internal_cfg.h"
> -#include "eal_filesystem.h"
> -#include "eal_private.h"
> +#include <eal_internal_cfg.h>
> +#include <eal_filesystem.h>
> +#include <eal_private.h>
>
>  /* Init the SoC EAL subsystem */
>  int
>  rte_eal_soc_init(void)
>  {
> +       struct rte_soc_driver *drv;
> +
> +       /* SoC is disabled by default */
> +       if (!internal_config.enable_soc)
> +               return 0;
> +
> +       /* For each registered driver, call their scan routine to perform any
> +        * custom scan for devices (for example, custom buses)
> +        */
> +       TAILQ_FOREACH(drv, &soc_driver_list, next) {
> +               RTE_VERIFY(drv->scan_fn);
> +               drv->scan_fn();
> +               /* Ignore all errors from this */
> +       }
> +
>         return 0;
>  }
> diff --git a/lib/librte_eal/linuxapp/eal/rte_eal_version.map b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> index 0155025..c28e093 100644
> --- a/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> +++ b/lib/librte_eal/linuxapp/eal/rte_eal_version.map
> @@ -175,7 +175,11 @@ DPDK_16.11 {
>         rte_eal_dev_attach;
>         rte_eal_dev_detach;
>         rte_eal_map_resource;
> +       rte_eal_soc_detach;
>         rte_eal_soc_dump;
> +       rte_eal_soc_match;
> +       rte_eal_soc_probe;
> +       rte_eal_soc_probe_one;
>         rte_eal_soc_register;
>         rte_eal_soc_unregister;
>         rte_eal_unmap_resource;
> --
> 2.7.4
>