Hello everyone,
This is the 2nd iteration of a series that introduces a new driver, for
the Qualcomm IPQESS Ethernet Controller, found on the IPQ4019.
Notables changes on V2 :
- Put the DSA tag in the skb itself instead of using skb->shinfo
- Fixed the initialisation sequence based on Andrew's comments
- Reworked the error paths in the init sequence
- Add support for the clock and reset lines on that controller
- Fixed and updated the binding
The driver itself is pretty straightforward, but has lived out-of-tree
for a while. I've done my best to clean-up some outdated API calls, but
some might remain.
This controller is somewhat special, since it's part of the IPQ4019 SoC
which also includes an QCA8K switch, and uses the IPQESS controller for
the CPU port. The switch is so tightly intergrated with the MAC that it
is connected to the MAC using an internal link (hence the fact that we
only support PHY_INTERFACE_MODE_INTERNAL), and this has some
consequences on the DSA side.
The tagging for the switch isn't done inband as most switch do, but
out-of-band, the DSA tag being included in the DMA descriptor.
This series includes a new out-of-band tagger that uses the skb headroom
to convey the tag between the tagger and the MAC driver.
Thanks to the Sartura folks who worked on a base version of this driver,
and provided test hardware.
Best regards,
Maxime Chevallier
Maxime Chevallier (5):
net: ipqess: introduce the Qualcomm IPQESS driver
net: dsa: add out-of-band tagging protocol
net: ipqess: Add out-of-band DSA tagging support
net: dt-bindings: Introduce the Qualcomm IPQESS Ethernet controller
ARM: dts: qcom: ipq4019: Add description for the IPQESS Ethernet
controller
.../devicetree/bindings/net/qcom,ipqess.yaml | 104 ++
MAINTAINERS | 6 +
arch/arm/boot/dts/qcom-ipq4019.dtsi | 46 +
drivers/net/ethernet/qualcomm/Kconfig | 12 +
drivers/net/ethernet/qualcomm/Makefile | 2 +
drivers/net/ethernet/qualcomm/ipqess/Makefile | 8 +
drivers/net/ethernet/qualcomm/ipqess/ipqess.c | 1296 +++++++++++++++++
drivers/net/ethernet/qualcomm/ipqess/ipqess.h | 518 +++++++
.../ethernet/qualcomm/ipqess/ipqess_ethtool.c | 168 +++
include/linux/dsa/oob.h | 17 +
include/net/dsa.h | 2 +
net/dsa/Kconfig | 7 +
net/dsa/Makefile | 1 +
net/dsa/tag_oob.c | 84 ++
14 files changed, 2271 insertions(+)
create mode 100644 Documentation/devicetree/bindings/net/qcom,ipqess.yaml
create mode 100644 drivers/net/ethernet/qualcomm/ipqess/Makefile
create mode 100644 drivers/net/ethernet/qualcomm/ipqess/ipqess.c
create mode 100644 drivers/net/ethernet/qualcomm/ipqess/ipqess.h
create mode 100644 drivers/net/ethernet/qualcomm/ipqess/ipqess_ethtool.c
create mode 100644 include/linux/dsa/oob.h
create mode 100644 net/dsa/tag_oob.c
--
2.36.1
Add the DT binding for the IPQESS Ethernet Controller. This is a simple
controller, only requiring the phy-mode, interrupts, clocks, and
possibly a MAC address setting.
Signed-off-by: Maxime Chevallier <[email protected]>
---
V1->V2:
- Fixed the example
- Added reset and clocks
- Removed generic ethernet attributes
.../devicetree/bindings/net/qcom,ipqess.yaml | 104 ++++++++++++++++++
1 file changed, 104 insertions(+)
create mode 100644 Documentation/devicetree/bindings/net/qcom,ipqess.yaml
diff --git a/Documentation/devicetree/bindings/net/qcom,ipqess.yaml b/Documentation/devicetree/bindings/net/qcom,ipqess.yaml
new file mode 100644
index 000000000000..ea0023509737
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/qcom,ipqess.yaml
@@ -0,0 +1,104 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/qcom,ipqess.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Qualcomm IPQ ESS EDMA Ethernet Controller
+
+maintainers:
+ - Maxime Chevallier <[email protected]>
+
+allOf:
+ - $ref: "ethernet-controller.yaml#"
+
+properties:
+ compatible:
+ const: qcom,ipq4019e-ess-edma
+
+ reg:
+ maxItems: 1
+
+ interrupts:
+ minItems: 2
+ maxItems: 32
+ description: One interrupt per tx and rx queue, with up to 16 queues.
+
+ clocks:
+ maxItems: 1
+
+ clock-names:
+ const: ess
+
+ resets:
+ maxItems: 1
+
+ reset-names:
+ const: ess
+
+required:
+ - compatible
+ - reg
+ - interrupts
+ - clocks
+ - clock-names
+ - resets
+ - phy-mode
+
+unevaluatedProperties: false
+
+examples:
+ - |
+ #include <dt-bindings/clock/qcom,gcc-ipq4019.h>
+ #include <dt-bindings/interrupt-controller/arm-gic.h>
+ #include <dt-bindings/interrupt-controller/irq.h>
+ gmac: ethernet@c080000 {
+ compatible = "qcom,ipq4019-ess-edma";
+ reg = <0xc080000 0x8000>;
+ resets = <&gcc ESS_RESET>;
+ reset-names = "ess";
+ clocks = <&gcc GCC_ESS_CLK>;
+ clock-names = "ess";
+ interrupts = <GIC_SPI 65 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 66 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 67 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 68 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 69 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 70 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 71 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 72 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 73 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 74 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 75 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 76 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 77 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 78 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 79 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 80 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 240 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 241 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 242 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 243 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 244 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 245 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 246 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 247 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 248 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 249 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 250 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 251 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 252 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 253 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 254 IRQ_TYPE_EDGE_RISING>,
+ <GIC_SPI 255 IRQ_TYPE_EDGE_RISING>;
+
+ phy-mode = "internal";
+ fixed-link {
+ speed = <1000>;
+ full-duplex;
+ pause;
+ asym-pause;
+ };
+ };
+
+...
--
2.36.1
This tagging protocol is designed for the situation where the link
between the MAC and the Switch is designed such that the Destination
Port, which is usually embedded in some part of the Ethernet Header, is
sent out-of-band, and isn't present at all in the Ethernet frame.
This can happen when the MAC and Switch are tightly integrated on an
SoC, as is the case with the Qualcomm IPQ4019 for example, where the DSA
tag is inserted directly into the DMA descriptors. In that case,
the MAC driver is responsible for sending the tag to the switch using
the out-of-band medium. To do so, the MAC driver needs to have the
information of the destination port for that skb.
This out-of-band tagging protocol is using the very beggining of the skb
headroom to store the tag. The drawback of this approch is that the
headroom isn't initialized upon allocating it, therefore we have a
chance that the garbage data that lies there at allocation time actually
ressembles a valid oob tag. This is only problematic if we are
sending/receiving traffic on the master port, which isn't a valid DSA
use-case from the beggining. When dealing from traffic to/from a slave
port, then the oob tag will be initialized properly by the tagger or the
mac driver through the use of the dsa_oob_tag_push() call.
Signed-off-by: Maxime Chevallier <[email protected]>
---
V1->V2:
- Reworked the tagging method, putting the tag at skb->head instead
of putting it into skb->shinfo, as per Andrew, Florian and Vlad's
reviews
include/linux/dsa/oob.h | 17 +++++++++
include/net/dsa.h | 2 +
net/dsa/Kconfig | 7 ++++
net/dsa/Makefile | 1 +
net/dsa/tag_oob.c | 84 +++++++++++++++++++++++++++++++++++++++++
5 files changed, 111 insertions(+)
create mode 100644 include/linux/dsa/oob.h
create mode 100644 net/dsa/tag_oob.c
diff --git a/include/linux/dsa/oob.h b/include/linux/dsa/oob.h
new file mode 100644
index 000000000000..dbb4a6fb1ce4
--- /dev/null
+++ b/include/linux/dsa/oob.h
@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ * Copyright (C) 2022 Maxime Chevallier <[email protected]>
+ */
+
+#ifndef _NET_DSA_OOB_H
+#define _NET_DSA_OOB_H
+
+#include <linux/skbuff.h>
+
+struct dsa_oob_tag_info {
+ u16 proto;
+ u16 dp;
+};
+
+int dsa_oob_tag_push(struct sk_buff *skb, struct dsa_oob_tag_info *ti);
+int dsa_oob_tag_pop(struct sk_buff *skb, struct dsa_oob_tag_info *ti);
+#endif
diff --git a/include/net/dsa.h b/include/net/dsa.h
index 14e10cda7267..9951df858912 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -53,6 +53,7 @@ struct phylink_link_state;
#define DSA_TAG_PROTO_SJA1110_VALUE 23
#define DSA_TAG_PROTO_RTL8_4_VALUE 24
#define DSA_TAG_PROTO_RTL8_4T_VALUE 25
+#define DSA_TAG_PROTO_OOB_VALUE 26
enum dsa_tag_protocol {
DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE,
@@ -81,6 +82,7 @@ enum dsa_tag_protocol {
DSA_TAG_PROTO_SJA1110 = DSA_TAG_PROTO_SJA1110_VALUE,
DSA_TAG_PROTO_RTL8_4 = DSA_TAG_PROTO_RTL8_4_VALUE,
DSA_TAG_PROTO_RTL8_4T = DSA_TAG_PROTO_RTL8_4T_VALUE,
+ DSA_TAG_PROTO_OOB = DSA_TAG_PROTO_OOB_VALUE,
};
struct dsa_switch;
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index 8cb87b5067ee..b7aa4d8552b2 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -57,6 +57,13 @@ config NET_DSA_TAG_HELLCREEK
Say Y or M if you want to enable support for tagging frames
for the Hirschmann Hellcreek TSN switches.
+config NET_DSA_TAG_OOB
+ tristate "Tag driver for Out-of-band tagging drivers"
+ help
+ Say Y or M if you want to enable support for tagging out-of-band. In
+ that case, the MAC driver becomes responsible for sending the tag to
+ the switch, outside the inband data.
+
config NET_DSA_TAG_GSWIP
tristate "Tag driver for Lantiq / Intel GSWIP switches"
help
diff --git a/net/dsa/Makefile b/net/dsa/Makefile
index 9f75820e7c98..b156e20f9c0a 100644
--- a/net/dsa/Makefile
+++ b/net/dsa/Makefile
@@ -9,6 +9,7 @@ obj-$(CONFIG_NET_DSA_TAG_BRCM_COMMON) += tag_brcm.o
obj-$(CONFIG_NET_DSA_TAG_DSA_COMMON) += tag_dsa.o
obj-$(CONFIG_NET_DSA_TAG_GSWIP) += tag_gswip.o
obj-$(CONFIG_NET_DSA_TAG_HELLCREEK) += tag_hellcreek.o
+obj-$(CONFIG_NET_DSA_TAG_OOB) += tag_oob.o
obj-$(CONFIG_NET_DSA_TAG_KSZ) += tag_ksz.o
obj-$(CONFIG_NET_DSA_TAG_LAN9303) += tag_lan9303.o
obj-$(CONFIG_NET_DSA_TAG_MTK) += tag_mtk.o
diff --git a/net/dsa/tag_oob.c b/net/dsa/tag_oob.c
new file mode 100644
index 000000000000..45ee3df5a7f9
--- /dev/null
+++ b/net/dsa/tag_oob.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/* Copyright (c) 2022, Maxime Chevallier <[email protected]> */
+
+#include <linux/bitfield.h>
+#include <linux/dsa/oob.h>
+
+#include "dsa_priv.h"
+
+#define DSA_OOB_TAG_LEN 4
+
+int dsa_oob_tag_push(struct sk_buff *skb, struct dsa_oob_tag_info *ti)
+{
+ struct dsa_oob_tag_info *tag_info;
+
+ tag_info = (struct dsa_oob_tag_info *)skb->head;
+
+ tag_info->proto = ti->proto;
+ tag_info->dp = ti->dp;
+
+ return 0;
+}
+EXPORT_SYMBOL(dsa_oob_tag_push);
+
+int dsa_oob_tag_pop(struct sk_buff *skb, struct dsa_oob_tag_info *ti)
+{
+ struct dsa_oob_tag_info *tag_info;
+
+ tag_info = (struct dsa_oob_tag_info *)skb->head;
+
+ if (tag_info->proto != DSA_TAG_PROTO_OOB)
+ return -EINVAL;
+
+ ti->proto = tag_info->proto;
+ ti->dp = tag_info->dp;
+
+ return 0;
+}
+EXPORT_SYMBOL(dsa_oob_tag_pop);
+
+static struct sk_buff *oob_tag_xmit(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct dsa_port *dp = dsa_slave_to_port(dev);
+ struct dsa_oob_tag_info tag_info;
+
+ tag_info.dp = dp->index;
+ tag_info.proto = DSA_TAG_PROTO_OOB;
+
+ if (dsa_oob_tag_push(skb, &tag_info))
+ return NULL;
+
+ return skb;
+}
+
+static struct sk_buff *oob_tag_rcv(struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct dsa_oob_tag_info tag_info;
+
+ if (dsa_oob_tag_pop(skb, &tag_info))
+ return NULL;
+
+ skb->dev = dsa_master_find_slave(dev, 0, tag_info.dp);
+ if (!skb->dev)
+ return NULL;
+
+ return skb;
+}
+
+const struct dsa_device_ops oob_tag_dsa_ops = {
+ .name = "oob",
+ .proto = DSA_TAG_PROTO_OOB,
+ .xmit = oob_tag_xmit,
+ .rcv = oob_tag_rcv,
+ .needed_headroom = DSA_OOB_TAG_LEN,
+};
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("DSA tag driver for out-of-band tagging");
+MODULE_AUTHOR("Maxime Chevallier <[email protected]>");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OOB);
+
+module_dsa_tag_driver(oob_tag_dsa_ops);
--
2.36.1
On the IPQ4019, there's an 5 ports switch connected to the CPU through
the IPQESS Ethernet controller. The way the DSA tag is sent-out to that
switch is through the DMA descriptor, due to how tightly it is
integrated with the switch.
This commit uses the out-of-band tagging protocol by getting the source
port from the descriptor, push it into the skb, and have the tagger pull
it to infer the destination netdev. The reverse process is done on the
TX side, where the driver pulls the tag from the skb and builds the
descriptor accordingly.
Signed-off-by: Maxime Chevallier <[email protected]>
---
V1->V2:
- Use the new tagger, and the dsa_oob_tag_* helpers
drivers/net/ethernet/qualcomm/Kconfig | 3 ++-
drivers/net/ethernet/qualcomm/ipqess/ipqess.c | 27 +++++++++++++++++++
2 files changed, 29 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/qualcomm/Kconfig b/drivers/net/ethernet/qualcomm/Kconfig
index a723ddbea248..eeb2c608d6b9 100644
--- a/drivers/net/ethernet/qualcomm/Kconfig
+++ b/drivers/net/ethernet/qualcomm/Kconfig
@@ -62,8 +62,9 @@ config QCOM_EMAC
config QCOM_IPQ4019_ESS_EDMA
tristate "Qualcomm Atheros IPQ4019 ESS EDMA support"
- depends on OF
+ depends on OF && NET_DSA
select PHYLINK
+ select NET_DSA_TAG_OOB
help
This driver supports the Qualcomm Atheros IPQ40xx built-in
ESS EDMA ethernet controller.
diff --git a/drivers/net/ethernet/qualcomm/ipqess/ipqess.c b/drivers/net/ethernet/qualcomm/ipqess/ipqess.c
index b11f11f23c11..a068dff19943 100644
--- a/drivers/net/ethernet/qualcomm/ipqess/ipqess.c
+++ b/drivers/net/ethernet/qualcomm/ipqess/ipqess.c
@@ -9,6 +9,7 @@
#include <linux/bitfield.h>
#include <linux/clk.h>
+#include <linux/dsa/oob.h>
#include <linux/if_vlan.h>
#include <linux/interrupt.h>
#include <linux/module.h>
@@ -22,6 +23,7 @@
#include <linux/skbuff.h>
#include <linux/vmalloc.h>
#include <net/checksum.h>
+#include <net/dsa.h>
#include <net/ip6_checksum.h>
#include "ipqess.h"
@@ -334,6 +336,7 @@ static int ipqess_rx_poll(struct ipqess_rx_ring *rx_ring, int budget)
tail &= IPQESS_RFD_CONS_IDX_MASK;
while (done < budget) {
+ struct dsa_oob_tag_info tag_info;
struct ipqess_rx_desc *rd;
struct sk_buff *skb;
@@ -413,6 +416,12 @@ static int ipqess_rx_poll(struct ipqess_rx_ring *rx_ring, int budget)
__vlan_hwaccel_put_tag(skb, htons(ETH_P_8021AD),
rd->rrd4);
+ if (netdev_uses_dsa(rx_ring->ess->netdev)) {
+ tag_info.dp = FIELD_GET(IPQESS_RRD_PORT_ID_MASK, rd->rrd1);
+ tag_info.proto = DSA_TAG_PROTO_OOB;
+ dsa_oob_tag_push(skb, &tag_info);
+ }
+
napi_gro_receive(&rx_ring->napi_rx, skb);
rx_ring->ess->stats.rx_packets++;
@@ -727,6 +736,22 @@ static void ipqess_rollback_tx(struct ipqess *eth,
tx_ring->head = start_index;
}
+static void ipqess_process_dsa_tag_sh(struct ipqess *ess, struct sk_buff *skb,
+ u32 *word3)
+{
+ struct dsa_oob_tag_info tag_info;
+
+ if (!netdev_uses_dsa(ess->netdev))
+ return;
+
+ if (dsa_oob_tag_pop(skb, &tag_info))
+ return;
+
+ *word3 |= tag_info.dp << IPQESS_TPD_PORT_BITMAP_SHIFT;
+ *word3 |= BIT(IPQESS_TPD_FROM_CPU_SHIFT);
+ *word3 |= 0x3e << IPQESS_TPD_PORT_BITMAP_SHIFT;
+}
+
static int ipqess_tx_map_and_fill(struct ipqess_tx_ring *tx_ring,
struct sk_buff *skb)
{
@@ -737,6 +762,8 @@ static int ipqess_tx_map_and_fill(struct ipqess_tx_ring *tx_ring,
u16 len;
int i;
+ ipqess_process_dsa_tag_sh(tx_ring->ess, skb, &word3);
+
if (skb_is_gso(skb)) {
if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
lso_word1 |= IPQESS_TPD_IPV4_EN;
--
2.36.1
On Sat, 14 May 2022 17:06:53 +0200 Maxime Chevallier wrote:
> This tagging protocol is designed for the situation where the link
> between the MAC and the Switch is designed such that the Destination
> Port, which is usually embedded in some part of the Ethernet Header, is
> sent out-of-band, and isn't present at all in the Ethernet frame.
>
> This can happen when the MAC and Switch are tightly integrated on an
> SoC, as is the case with the Qualcomm IPQ4019 for example, where the DSA
> tag is inserted directly into the DMA descriptors. In that case,
> the MAC driver is responsible for sending the tag to the switch using
> the out-of-band medium. To do so, the MAC driver needs to have the
> information of the destination port for that skb.
>
> This out-of-band tagging protocol is using the very beggining of the skb
> headroom to store the tag. The drawback of this approch is that the
> headroom isn't initialized upon allocating it, therefore we have a
> chance that the garbage data that lies there at allocation time actually
> ressembles a valid oob tag. This is only problematic if we are
> sending/receiving traffic on the master port, which isn't a valid DSA
> use-case from the beggining. When dealing from traffic to/from a slave
> port, then the oob tag will be initialized properly by the tagger or the
> mac driver through the use of the dsa_oob_tag_push() call.
>
> Signed-off-by: Maxime Chevallier <[email protected]>
This must had been asked on v1 but there's no trace of it in the
current submission afaict...
If the tag is passed in the descriptor how is this not a pure switchdev
driver? The explanation must be preserved somehow.
On Sat, May 14, 2022 at 05:06:55PM +0200, Maxime Chevallier wrote:
> Add the DT binding for the IPQESS Ethernet Controller. This is a simple
> controller, only requiring the phy-mode, interrupts, clocks, and
> possibly a MAC address setting.
>
> Signed-off-by: Maxime Chevallier <[email protected]>
> ---
> V1->V2:
> - Fixed the example
> - Added reset and clocks
> - Removed generic ethernet attributes
>
> .../devicetree/bindings/net/qcom,ipqess.yaml | 104 ++++++++++++++++++
> 1 file changed, 104 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/net/qcom,ipqess.yaml
>
> diff --git a/Documentation/devicetree/bindings/net/qcom,ipqess.yaml b/Documentation/devicetree/bindings/net/qcom,ipqess.yaml
> new file mode 100644
> index 000000000000..ea0023509737
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/net/qcom,ipqess.yaml
> @@ -0,0 +1,104 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/net/qcom,ipqess.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Qualcomm IPQ ESS EDMA Ethernet Controller
> +
> +maintainers:
> + - Maxime Chevallier <[email protected]>
> +
> +allOf:
> + - $ref: "ethernet-controller.yaml#"
> +
> +properties:
> + compatible:
> + const: qcom,ipq4019e-ess-edma
> +
> + reg:
> + maxItems: 1
> +
> + interrupts:
> + minItems: 2
> + maxItems: 32
> + description: One interrupt per tx and rx queue, with up to 16 queues.
> +
> + clocks:
> + maxItems: 1
> +
> + clock-names:
> + const: ess
Always kind of pointless to have a single *-names entry when it's just
the block name.
> +
> + resets:
> + maxItems: 1
> +
> + reset-names:
> + const: ess
ditto
> +
> +required:
> + - compatible
> + - reg
> + - interrupts
> + - clocks
> + - clock-names
> + - resets
> + - phy-mode
> +
> +unevaluatedProperties: false
> +
> +examples:
> + - |
> + #include <dt-bindings/clock/qcom,gcc-ipq4019.h>
> + #include <dt-bindings/interrupt-controller/arm-gic.h>
> + #include <dt-bindings/interrupt-controller/irq.h>
> + gmac: ethernet@c080000 {
> + compatible = "qcom,ipq4019-ess-edma";
> + reg = <0xc080000 0x8000>;
> + resets = <&gcc ESS_RESET>;
> + reset-names = "ess";
> + clocks = <&gcc GCC_ESS_CLK>;
> + clock-names = "ess";
> + interrupts = <GIC_SPI 65 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 66 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 67 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 68 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 69 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 70 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 71 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 72 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 73 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 74 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 75 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 76 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 77 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 78 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 79 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 80 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 240 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 241 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 242 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 243 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 244 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 245 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 246 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 247 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 248 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 249 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 250 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 251 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 252 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 253 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 254 IRQ_TYPE_EDGE_RISING>,
> + <GIC_SPI 255 IRQ_TYPE_EDGE_RISING>;
> +
> + phy-mode = "internal";
> + fixed-link {
> + speed = <1000>;
> + full-duplex;
> + pause;
> + asym-pause;
> + };
> + };
> +
> +...
> --
> 2.36.1
>
>
Hello Jakub,
On Mon, 16 May 2022 12:20:48 -0700
Jakub Kicinski <[email protected]> wrote:
> On Sat, 14 May 2022 17:06:53 +0200 Maxime Chevallier wrote:
> > This tagging protocol is designed for the situation where the link
> > between the MAC and the Switch is designed such that the Destination
> > Port, which is usually embedded in some part of the Ethernet
> > Header, is sent out-of-band, and isn't present at all in the
> > Ethernet frame.
> >
> > This can happen when the MAC and Switch are tightly integrated on an
> > SoC, as is the case with the Qualcomm IPQ4019 for example, where
> > the DSA tag is inserted directly into the DMA descriptors. In that
> > case, the MAC driver is responsible for sending the tag to the
> > switch using the out-of-band medium. To do so, the MAC driver needs
> > to have the information of the destination port for that skb.
> >
> > This out-of-band tagging protocol is using the very beggining of
> > the skb headroom to store the tag. The drawback of this approch is
> > that the headroom isn't initialized upon allocating it, therefore
> > we have a chance that the garbage data that lies there at
> > allocation time actually ressembles a valid oob tag. This is only
> > problematic if we are sending/receiving traffic on the master port,
> > which isn't a valid DSA use-case from the beggining. When dealing
> > from traffic to/from a slave port, then the oob tag will be
> > initialized properly by the tagger or the mac driver through the
> > use of the dsa_oob_tag_push() call.
> >
> > Signed-off-by: Maxime Chevallier <[email protected]>
>
> This must had been asked on v1 but there's no trace of it in the
> current submission afaict...
No you're correct, this wasn't explained.
> If the tag is passed in the descriptor how is this not a pure
> switchdev driver? The explanation must be preserved somehow.
The main reason is that although the MAC and switch are rightly coupled
on that platform, the switch is actually a QC8K that can live on it's
own, as an external switch. Here, it's just a slightly modified version
of this IP.
The same goes for the MAC IP, but so far we don't support any other
platform that have the MAC as a standalone controller. As far as we can
tell, platforms that have this MAC also include a QCA8K, but the
datasheet also mentions other modes (like outputing RGMII).
Is this valid to have it as a standalone ethernet driver in that
situation ?
Thanks,
Maxime
On Tue, 17 May 2022 08:53:55 +0200 Maxime Chevallier wrote:
> > This must had been asked on v1 but there's no trace of it in the
> > current submission afaict...
>
> No you're correct, this wasn't explained.
>
> > If the tag is passed in the descriptor how is this not a pure
> > switchdev driver? The explanation must be preserved somehow.
>
> The main reason is that although the MAC and switch are rightly coupled
> on that platform, the switch is actually a QC8K that can live on it's
> own, as an external switch. Here, it's just a slightly modified version
> of this IP.
>
> The same goes for the MAC IP, but so far we don't support any other
> platform that have the MAC as a standalone controller. As far as we can
> tell, platforms that have this MAC also include a QCA8K, but the
> datasheet also mentions other modes (like outputing RGMII).
Got it, thanks! Please weave this justification more explicitly into
the cover letter.
> Is this valid to have it as a standalone ethernet driver in that
> situation ?
Quite possibly.. I won't pretend I've looked at the code, I defer
to the reviewers :)