Re: [dpdk-dev] [PATCH v8 06/12] eal: Add pci_uio_alloc_resource()

[David Marchand <david.marchand@6wind.com>]

On Mon, Jul 6, 2015 at 8:24 AM, Tetsuya Mukawa <mukawa@igel.co.jp> wrote:

> From: "Tetsuya.Mukawa" <mukawa@igel.co.jp>
>
> This patch adds a new function called pci_uio_alloc_resource().
> The function hides how to prepare uio resource in linuxapp and bsdapp.
> With the function, pci_uio_map_resource() will be more abstracted.
>
> Signed-off-by: Tetsuya Mukawa <mukawa@igel.co.jp>
> ---
>  lib/librte_eal/bsdapp/eal/eal_pci.c       | 84 +++++++++++++++++---------
>  lib/librte_eal/linuxapp/eal/eal_pci_uio.c | 98
> +++++++++++++++++++++----------
>  2 files changed, 123 insertions(+), 59 deletions(-)
>
> diff --git a/lib/librte_eal/bsdapp/eal/eal_pci.c
> b/lib/librte_eal/bsdapp/eal/eal_pci.c
> index 92d9886..ce0ca07 100644
> --- a/lib/librte_eal/bsdapp/eal/eal_pci.c
> +++ b/lib/librte_eal/bsdapp/eal/eal_pci.c
> @@ -189,28 +189,17 @@ pci_uio_map_secondary(struct rte_pci_device *dev)
>         return 1;
>  }
>
> -/* map the PCI resource of a PCI device in virtual memory */
>  static int
> -pci_uio_map_resource(struct rte_pci_device *dev)
> +pci_uio_alloc_resource(struct rte_pci_device *dev,
> +               struct mapped_pci_resource **uio_res)
>  {
> -       int i, map_idx = 0;
>         char devname[PATH_MAX]; /* contains the /dev/uioX */
> -       void *mapaddr;
> -       uint64_t phaddr;
> -       uint64_t offset;
> -       uint64_t pagesz;
> -       struct rte_pci_addr *loc = &dev->addr;
> -       struct mapped_pci_resource *uio_res = NULL;
> -       struct mapped_pci_res_list *uio_res_list =
> -                       RTE_TAILQ_CAST(rte_uio_tailq.head,
> mapped_pci_res_list);
> -       struct pci_map *maps;
> +       struct rte_pci_addr *loc;
>
> -       dev->intr_handle.fd = -1;
> -       dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
> +       if ((dev == NULL) || (uio_res == NULL))
> +               return -1;
>
>
This is an "internal" function, dev cannot be null, neither uio_res.


> -       /* secondary processes - use already recorded details */
> -       if (rte_eal_process_type() != RTE_PROC_PRIMARY)
> -               return pci_uio_map_secondary(dev);
> +       loc = &dev->addr;
>
>         snprintf(devname, sizeof(devname), "/dev/uio@pci:%u:%u:%u",
>                         dev->addr.bus, dev->addr.devid,
> dev->addr.function);
> @@ -231,18 +220,57 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>         dev->intr_handle.type = RTE_INTR_HANDLE_UIO;
>
>         /* allocate the mapping details for secondary processes*/
> -       if ((uio_res = rte_zmalloc("UIO_RES", sizeof (*uio_res), 0)) ==
> NULL) {
> +       *uio_res = rte_zmalloc("UIO_RES", sizeof(**uio_res), 0);
> +       if (*uio_res == NULL) {
>                 RTE_LOG(ERR, EAL,
>                         "%s(): cannot store uio mmap details\n", __func__);
>                 goto error;
>         }
>
> -       snprintf(uio_res->path, sizeof(uio_res->path), "%s", devname);
> -       memcpy(&uio_res->pci_addr, &dev->addr, sizeof(uio_res->pci_addr));
> +       snprintf((*uio_res)->path, sizeof((*uio_res)->path), "%s",
> devname);
> +       memcpy(&(*uio_res)->pci_addr, &dev->addr,
> sizeof((*uio_res)->pci_addr));
>
> +       return 0;
> +
> +error:
> +       if (dev->intr_handle.fd) {
> +               close(dev->intr_handle.fd);
> +               dev->intr_handle.fd = -1;
> +               dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
> +       }
> +       return -1;
> +}
> +
> +/* map the PCI resource of a PCI device in virtual memory */
> +static int
> +pci_uio_map_resource(struct rte_pci_device *dev)
> +{
> +       int i, map_idx = 0, ret;
> +       char *devname;
> +       void *mapaddr;
> +       uint64_t phaddr;
> +       uint64_t offset;
> +       uint64_t pagesz;
> +       struct mapped_pci_resource *uio_res = NULL;
> +       struct mapped_pci_res_list *uio_res_list =
> +               RTE_TAILQ_CAST(rte_uio_tailq.head, mapped_pci_res_list);
> +       struct pci_map *maps;
> +
> +       dev->intr_handle.fd = -1;
> +       dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
> +
> +       /* secondary processes - use already recorded details */
> +       if (rte_eal_process_type() != RTE_PROC_PRIMARY)
> +               return pci_uio_map_secondary(dev);
> +
> +       /* allocate uio resource */
> +       ret = pci_uio_alloc_resource(dev, &uio_res);
> +       if ((ret != 0) || (uio_res == NULL))
> +               return ret;
>
>
If ret != 0, uio_res cannot be NULL.



>         /* Map all BARs */
>         pagesz = sysconf(_SC_PAGESIZE);
> +       devname = uio_res->path;
>
>         maps = uio_res->maps;
>         for (i = 0; i != PCI_MAX_RESOURCE; i++) {
> @@ -298,13 +326,15 @@ pci_uio_map_resource(struct rte_pci_device *dev)
>  error:
>         for (i = 0; i < map_idx; i++)
>                 rte_free(maps[i].path);
> -       if (uio_res)
> -               rte_free(uio_res);
> -       if (dev->intr_handle.fd >= 0) {
> -               close(dev->intr_handle.fd);
> -               dev->intr_handle.fd = -1;
> -               dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
> -       }
> +
> +       /* 'uio_res' has valid value here */
>

Not sure what this comment means, do you mean != NULL ? It does not matter.


> +       rte_free(uio_res);
> +
> +       /* 'fd' has valid value here */
> +       close(dev->intr_handle.fd);
> +       dev->intr_handle.fd = -1;
> +       dev->intr_handle.type = RTE_INTR_HANDLE_UNKNOWN;
> +
>         return -1;
>  }
>

In the end, if you add this "alloc" function, why not introduce a "free"
function that does this cleanup ?


Same comments apply to linux modifications.


-- 
David Marchand