On Mon, Feb 17, 2020 at 10:20:09PM -0800, Selvin Xavier wrote:
> Adding a helper function to retrieve the driver gid context
> from the gid attr.
>
> Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
> Signed-off-by: Selvin Xavier <selvin.xavier@xxxxxxxxxxxx>
> drivers/infiniband/core/cache.c | 41 +++++++++++++++++++++++++++++++++++++++++
> include/rdma/ib_cache.h | 1 +
> 2 files changed, 42 insertions(+)
>
> diff --git a/drivers/infiniband/core/cache.c b/drivers/infiniband/core/cache.c
> index 17bfedd..1b73a71 100644
> +++ b/drivers/infiniband/core/cache.c
> @@ -973,6 +973,47 @@ int rdma_query_gid(struct ib_device *device, u8 port_num,
> EXPORT_SYMBOL(rdma_query_gid);
>
> /**
> + * rdma_read_gid_hw_context - Read the HW GID context from GID attribute
> + * @attr: Potinter to the GID attribute
> + *
> + * rdma_read_gid_hw_context() reads the vendor drivers GID HW
> + * context corresponding to SGID attr. It takes reference to the GID
> + * attribute and this need to be released by the caller using
> + * rdma_put_gid_attr
> + *
> + * Returns HW context on success or NULL on error
> + *
> + */
> +void *rdma_read_gid_hw_context(const struct ib_gid_attr *attr)
> +{
> + struct ib_gid_table_entry *entry =
> + container_of(attr, struct ib_gid_table_entry, attr);
> + struct ib_device *device = entry->attr.device;
> + u8 port_num = entry->attr.port_num;
> + struct ib_gid_table *table;
> + unsigned long flags;
> + void *context = NULL;
> +
> + if (!rdma_is_port_valid(device, port_num))
> + return NULL;
> +
> + table = rdma_gid_table(device, port_num);
> + read_lock_irqsave(&table->rwlock, flags);
> +
> + if (attr->index < 0 || attr->index >= table->sz ||
> + !is_gid_entry_valid(table->data_vec[attr->index]))
> + goto done;
Why all this validation and locking? ib_gid_attrs are only created by
the core code..
> + get_gid_entry(entry);
And why a get? Surely it is invalid to call this function without a
get already held?
Jason
