Re: [PATCH net-next v5 02/13] net: wwan: t7xx: Add control DMA interface

[Sergey Ryazanov <ryazanov.s.a@gmail.com>]

On Thu, Feb 24, 2022 at 1:35 AM Ricardo Martinez
<ricardo.martinez@linux.intel.com> wrote:
> From: Haijun Liu <haijun.liu@mediatek.com>
>
> Cross Layer DMA (CLDMA) Hardware interface (HIF) enables the control
> path of Host-Modem data transfers. CLDMA HIF layer provides a common
> interface to the Port Layer.
>
> CLDMA manages 8 independent RX/TX physical channels with data flow
> control in HW queues. CLDMA uses ring buffers of General Packet
> Descriptors (GPD) for TX/RX. GPDs can represent multiple or single
> data buffers (DB).
>
> CLDMA HIF initializes GPD rings, registers ISR handlers for CLDMA
> interrupts, and initializes CLDMA HW registers.
>
> CLDMA TX flow:
> 1. Port Layer write
> 2. Get DB address
> 3. Configure GPD
> 4. Triggering processing via HW register write
>
> CLDMA RX flow:
> 1. CLDMA HW sends a RX "done" to host
> 2. Driver starts thread to safely read GPD
> 3. DB is sent to Port layer
> 4. Create a new buffer for GPD ring
>
> Signed-off-by: Haijun Liu <haijun.liu@mediatek.com>
> Signed-off-by: Chandrashekar Devegowda <chandrashekar.devegowda@intel.com>
> Co-developed-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
> Signed-off-by: Ricardo Martinez <ricardo.martinez@linux.intel.com>
>
> From a WWAN framework perspective:
> Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
> ---
>  drivers/net/wwan/t7xx/t7xx_cldma.c     |  281 ++++++
>  drivers/net/wwan/t7xx/t7xx_cldma.h     |  176 ++++
>  drivers/net/wwan/t7xx/t7xx_common.h    |   40 +
>  drivers/net/wwan/t7xx/t7xx_hif_cldma.c | 1204 ++++++++++++++++++++++++
>  drivers/net/wwan/t7xx/t7xx_hif_cldma.h |  141 +++
>  drivers/net/wwan/t7xx/t7xx_reg.h       |   33 +
>  6 files changed, 1875 insertions(+)
>  create mode 100644 drivers/net/wwan/t7xx/t7xx_cldma.c
>  create mode 100644 drivers/net/wwan/t7xx/t7xx_cldma.h
>  create mode 100644 drivers/net/wwan/t7xx/t7xx_common.h
>  create mode 100644 drivers/net/wwan/t7xx/t7xx_hif_cldma.c
>  create mode 100644 drivers/net/wwan/t7xx/t7xx_hif_cldma.h
>  create mode 100644 drivers/net/wwan/t7xx/t7xx_reg.h
>
> diff --git a/drivers/net/wwan/t7xx/t7xx_cldma.c b/drivers/net/wwan/t7xx/t7xx_cldma.c
> new file mode 100644
> index 000000000000..2713d9a6034b
> --- /dev/null
> +++ b/drivers/net/wwan/t7xx/t7xx_cldma.c
> @@ -0,0 +1,281 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2021, MediaTek Inc.
> + * Copyright (c) 2021-2022, Intel Corporation.
> + *
> + * Authors:
> + *  Haijun Liu <haijun.liu@mediatek.com>
> + *  Moises Veleta <moises.veleta@intel.com>
> + *  Ricardo Martinez<ricardo.martinez@linux.intel.com>

The space is missed between name and email. The same issue repeated in
every file of the series.

[skipped]

> +#ifdef NET_SKBUFF_DATA_USES_OFFSET
> +static inline unsigned int t7xx_skb_data_area_size(struct sk_buff *skb)
> +{
> +       return skb->head + skb->end - skb->data;
> +}
> +#else
> +static inline unsigned int t7xx_skb_data_area_size(struct sk_buff *skb)
> +{
> +       return skb->end - skb->data;
> +}
> +#endif

You can use skb_end_pointer() to avoid conditional compilation.

--
Sergey