> Subject: [PATCH net] net: mana: Support holes in device list reply msg
>
> According to GDMA protocol, holes (zeros) are allowed at the beginning or middle
> of the gdma_list_devices_resp message. The existing code cannot properly
> handle this, and may miss some devices in the list.
>
> To fix, scan the entire list until the num_of_devs are found, or until the end of the
> list.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: ca9c54d2d6a5 ("net: mana: Add a driver for Microsoft Azure Network
> Adapter (MANA)")
> Signed-off-by: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
Reviewed-by: Long Li <longli@xxxxxxxxxxxxx>
>
> ---
> drivers/net/ethernet/microsoft/mana/gdma_main.c | 16 ++++++++++++----
> include/net/mana/gdma.h | 11 +++++++----
> 2 files changed, 19 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/net/ethernet/microsoft/mana/gdma_main.c
> b/drivers/net/ethernet/microsoft/mana/gdma_main.c
> index c15a5ef4674e..df3ab31974b1 100644
> --- a/drivers/net/ethernet/microsoft/mana/gdma_main.c
> +++ b/drivers/net/ethernet/microsoft/mana/gdma_main.c
> @@ -134,9 +134,10 @@ static int mana_gd_detect_devices(struct pci_dev
> *pdev)
> struct gdma_list_devices_resp resp = {};
> struct gdma_general_req req = {};
> struct gdma_dev_id dev;
> - u32 i, max_num_devs;
> + int found_dev = 0;
> u16 dev_type;
> int err;
> + u32 i;
>
> mana_gd_init_req_hdr(&req.hdr, GDMA_LIST_DEVICES, sizeof(req),
> sizeof(resp));
> @@ -148,12 +149,19 @@ static int mana_gd_detect_devices(struct pci_dev
> *pdev)
> return err ? err : -EPROTO;
> }
>
> - max_num_devs = min_t(u32, MAX_NUM_GDMA_DEVICES,
> resp.num_of_devs);
> -
> - for (i = 0; i < max_num_devs; i++) {
> + for (i = 0; i < GDMA_DEV_LIST_SIZE &&
> + found_dev < resp.num_of_devs; i++) {
> dev = resp.devs[i];
> dev_type = dev.type;
>
> + /* Skip empty devices */
> + if (dev.as_uint32 == 0)
> + continue;
> +
> + found_dev++;
> + dev_info(gc->dev, "Got devidx:%u, type:%u, instance:%u\n", i,
> + dev.type, dev.instance);
> +
> /* HWC is already detected in mana_hwc_create_channel(). */
> if (dev_type == GDMA_DEVICE_HWC)
> continue;
> diff --git a/include/net/mana/gdma.h b/include/net/mana/gdma.h index
> 90f56656b572..62e9d7673862 100644
> --- a/include/net/mana/gdma.h
> +++ b/include/net/mana/gdma.h
> @@ -408,8 +408,6 @@ struct gdma_context {
> struct gdma_dev mana_ib;
> };
>
> -#define MAX_NUM_GDMA_DEVICES 4
> -
> static inline bool mana_gd_is_mana(struct gdma_dev *gd) {
> return gd->dev_id.type == GDMA_DEVICE_MANA; @@ -556,11 +554,15
> @@ enum { #define GDMA_DRV_CAP_FLAG_1_HWC_TIMEOUT_RECONFIG
> BIT(3) #define
> GDMA_DRV_CAP_FLAG_1_VARIABLE_INDIRECTION_TABLE_SUPPORT BIT(5)
>
> +/* Driver can handle holes (zeros) in the device list */ #define
> +GDMA_DRV_CAP_FLAG_1_DEV_LIST_HOLES_SUP BIT(11)
> +
> #define GDMA_DRV_CAP_FLAGS1 \
> (GDMA_DRV_CAP_FLAG_1_EQ_SHARING_MULTI_VPORT | \
> GDMA_DRV_CAP_FLAG_1_NAPI_WKDONE_FIX | \
> GDMA_DRV_CAP_FLAG_1_HWC_TIMEOUT_RECONFIG | \
> - GDMA_DRV_CAP_FLAG_1_VARIABLE_INDIRECTION_TABLE_SUPPORT)
> + GDMA_DRV_CAP_FLAG_1_VARIABLE_INDIRECTION_TABLE_SUPPORT |
> \
> + GDMA_DRV_CAP_FLAG_1_DEV_LIST_HOLES_SUP)
>
> #define GDMA_DRV_CAP_FLAGS2 0
>
> @@ -621,11 +623,12 @@ struct gdma_query_max_resources_resp { }; /* HW
> DATA */
>
> /* GDMA_LIST_DEVICES */
> +#define GDMA_DEV_LIST_SIZE 64
> struct gdma_list_devices_resp {
> struct gdma_resp_hdr hdr;
> u32 num_of_devs;
> u32 reserved;
> - struct gdma_dev_id devs[64];
> + struct gdma_dev_id devs[GDMA_DEV_LIST_SIZE];
> }; /* HW DATA */
>
> /* GDMA_REGISTER_DEVICE */
> --
> 2.34.1
