Thread (45 messages) 45 messages, 3 authors, 2022-04-05

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

From: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Date: 2022-03-07 02:42:49
Also in: linux-wireless

On Thu, Feb 24, 2022 at 1:35 AM Ricardo Martinez
[off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <redacted>
---
 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
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