Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Sun, 25 Jun 2023 15:47:19 +0300
From:   Vladimir Oltean <olteanv@gmail.com>
To:     Pawel Dembicki <paweldembicki@gmail.com>
Cc:     netdev@vger.kernel.org, Linus Walleij <linus.walleij@linaro.org>,
        Andrew Lunn <andrew@lunn.ch>,
        Florian Fainelli <f.fainelli@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next v2 4/7] net: dsa: vsc73xx: Add dsa tagging based
 on 8021q
Message-ID: <20230625124719.6yn7z2r2kfds5kbv@skbuf>
References: <20230625115343.1603330-1-paweldembicki@gmail.com>
 <20230625115343.1603330-4-paweldembicki@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20230625115343.1603330-4-paweldembicki@gmail.com>
Precedence: bulk

On Sun, Jun 25, 2023 at 01:53:39PM +0200, Pawel Dembicki wrote:
> This patch is simple implementation of 8021q tagging in vsc73xx driver.
> At this moment devices with DSA_TAG_PROTO_NONE are useless. VSC73XX
> family doesn't provide any tag support for external ethernet ports.
> 
> The only way is vlan-based tagging. It require constant hardware vlan
> filtering. VSC73XX family support provider bridging but QinQ only without
> fully implemented 802.1AD. It allow only doubled 0x8100 TPID.
> 
> In simple port mode QinQ is enabled to preserve forwarding vlan tagged
> frames.
> 
> Tag driver introduce most simple funcionality required for proper taging
> support.
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Pawel Dembicki <paweldembicki@gmail.com>
> ---
> v2:
>   - change poll loop into dedicated macro
>   - fix style issues
> 
>  drivers/net/dsa/Kconfig                |   2 +-
>  drivers/net/dsa/vitesse-vsc73xx-core.c | 532 +++++++++++++++++++++----
>  include/net/dsa.h                      |   2 +
>  net/dsa/Kconfig                        |   6 +
>  net/dsa/Makefile                       |   1 +
>  net/dsa/tag_vsc73xx_8021q.c            |  87 ++++
>  6 files changed, 544 insertions(+), 86 deletions(-)
>  create mode 100644 net/dsa/tag_vsc73xx_8021q.c
> 
> diff --git a/drivers/net/dsa/Kconfig b/drivers/net/dsa/Kconfig
> index 3ed5391bb18d..4cf0166fef7b 100644
> --- a/drivers/net/dsa/Kconfig
> +++ b/drivers/net/dsa/Kconfig
> @@ -125,7 +125,7 @@ config NET_DSA_SMSC_LAN9303_MDIO
>  
>  config NET_DSA_VITESSE_VSC73XX
>  	tristate
> -	select NET_DSA_TAG_NONE
> +	select NET_DSA_TAG_VSC73XX
>  	select FIXED_PHY
>  	select VITESSE_PHY
>  	select GPIOLIB
> diff --git a/drivers/net/dsa/vitesse-vsc73xx-core.c b/drivers/net/dsa/vitesse-vsc73xx-core.c
> index f123ce2ed244..f7c38f9a81a8 100644
> --- a/drivers/net/dsa/vitesse-vsc73xx-core.c
> +++ b/drivers/net/dsa/vitesse-vsc73xx-core.c
> @@ -17,6 +17,7 @@
>  #include <linux/kernel.h>
>  #include <linux/module.h>
>  #include <linux/device.h>
> +#include <linux/iopoll.h>
>  #include <linux/of.h>
>  #include <linux/of_device.h>
>  #include <linux/of_mdio.h>
> @@ -25,6 +26,7 @@
>  #include <linux/etherdevice.h>
>  #include <linux/gpio/consumer.h>
>  #include <linux/gpio/driver.h>
> +#include <linux/dsa/8021q.h>
>  #include <linux/random.h>
>  #include <net/dsa.h>
>  
> @@ -62,6 +64,8 @@
>  #define VSC73XX_CAT_DROP	0x6e
>  #define VSC73XX_CAT_PR_MISC_L2	0x6f
>  #define VSC73XX_CAT_PR_USR_PRIO	0x75
> +#define VSC73XX_CAT_VLAN_MISC	0x79
> +#define VSC73XX_CAT_PORT_VLAN	0x7a
>  #define VSC73XX_Q_MISC_CONF	0xdf
>  
>  /* MAC_CFG register bits */
> @@ -122,6 +126,17 @@
>  #define VSC73XX_ADVPORTM_IO_LOOPBACK	BIT(1)
>  #define VSC73XX_ADVPORTM_HOST_LOOPBACK	BIT(0)
>  
> +/*  TXUPDCFG transmit modify setup bits */
> +#define VSC73XX_TXUPDCFG_DSCP_REWR_MODE	GENMASK(20, 19)
> +#define VSC73XX_TXUPDCFG_DSCP_REWR_ENA	BIT(18)
> +#define VSC73XX_TXUPDCFG_TX_INT_TO_USRPRIO_ENA	BIT(17)
> +#define VSC73XX_TXUPDCFG_TX_UNTAGGED_VID	GENMASK(15, 4)
> +#define VSC73XX_TXUPDCFG_TX_UNTAGGED_VID_ENA	BIT(3)
> +#define VSC73XX_TXUPDCFG_TX_UPDATE_CRC_CPU_ENA	BIT(1)
> +#define VSC73XX_TXUPDCFG_TX_INSERT_TAG	BIT(0)
> +
> +#define VSC73XX_TXUPDCFG_TX_UNTAGGED_VID_SHIFT 4
> +
>  /* CAT_DROP categorizer frame dropping register bits */
>  #define VSC73XX_CAT_DROP_DROP_MC_SMAC_ENA	BIT(6)
>  #define VSC73XX_CAT_DROP_FWD_CTRL_ENA		BIT(4)
> @@ -135,6 +150,15 @@
>  #define VSC73XX_Q_MISC_CONF_EARLY_TX_512	(1 << 1)
>  #define VSC73XX_Q_MISC_CONF_MAC_PAUSE_MODE	BIT(0)
>  
> +/* CAT_VLAN_MISC categorizer VLAN miscellaneous bits*/
> +#define VSC73XX_CAT_VLAN_MISC_VLAN_TCI_IGNORE_ENA BIT(8)
> +#define VSC73XX_CAT_VLAN_MISC_VLAN_KEEP_TAG_ENA BIT(7)
> +
> +/* CAT_PORT_VLAN categorizer port VLAN*/
> +#define VSC73XX_CAT_PORT_VLAN_VLAN_CFI BIT(15)
> +#define VSC73XX_CAT_PORT_VLAN_VLAN_USR_PRIO GENMASK(14, 12)
> +#define VSC73XX_CAT_PORT_VLAN_VLAN_VID GENMASK(11, 0)
> +
>  /* Frame analyzer block 2 registers */
>  #define VSC73XX_STORMLIMIT	0x02
>  #define VSC73XX_ADVLEARN	0x03
> @@ -189,7 +213,8 @@
>  #define VSC73XX_VLANACCESS_VLAN_MIRROR		BIT(29)
>  #define VSC73XX_VLANACCESS_VLAN_SRC_CHECK	BIT(28)
>  #define VSC73XX_VLANACCESS_VLAN_PORT_MASK	GENMASK(9, 2)
> -#define VSC73XX_VLANACCESS_VLAN_TBL_CMD_MASK	GENMASK(2, 0)
> +#define VSC73XX_VLANACCESS_VLAN_PORT_MASK_SHIFT	2
> +#define VSC73XX_VLANACCESS_VLAN_TBL_CMD_MASK	GENMASK(1, 0)
>  #define VSC73XX_VLANACCESS_VLAN_TBL_CMD_IDLE	0
>  #define VSC73XX_VLANACCESS_VLAN_TBL_CMD_READ_ENTRY	1
>  #define VSC73XX_VLANACCESS_VLAN_TBL_CMD_WRITE_ENTRY	2
> @@ -344,6 +369,13 @@ static const struct vsc73xx_counter vsc73xx_tx_counters[] = {
>  	{ 29, "TxQoSClass3" }, /* non-standard counter */
>  };
>  
> +enum vsc73xx_port_vlan_conf {
> +	VSC73XX_VLAN_UNAWARE,
> +	VSC73XX_VLAN_AWARE,
> +	VSC73XX_DOUBLE_VLAN_AWARE,
> +	VSC73XX_DOUBLE_VLAN_CPU_AWARE,
> +};
> +
>  int vsc73xx_is_addr_valid(u8 block, u8 subblock)
>  {
>  	switch (block) {
> @@ -558,90 +590,7 @@ static enum dsa_tag_protocol vsc73xx_get_tag_protocol(struct dsa_switch *ds,
>  	 * cannot access the tag. (See "Internal frame header" section
>  	 * 3.9.1 in the manual.)
>  	 */
> -	return DSA_TAG_PROTO_NONE;
> -}
> -
> -static int vsc73xx_setup(struct dsa_switch *ds)
> -{
> -	struct vsc73xx *vsc = ds->priv;
> -	int i;
> -
> -	dev_info(vsc->dev, "set up the switch\n");
> -
> -	/* Issue RESET */
> -	vsc73xx_write(vsc, VSC73XX_BLOCK_SYSTEM, 0, VSC73XX_GLORESET,
> -		      VSC73XX_GLORESET_MASTER_RESET);
> -	usleep_range(125, 200);
> -
> -	/* Initialize memory, initialize RAM bank 0..15 except 6 and 7
> -	 * This sequence appears in the
> -	 * VSC7385 SparX-G5 datasheet section 6.6.1
> -	 * VSC7395 SparX-G5e datasheet section 6.6.1
> -	 * "initialization sequence".
> -	 * No explanation is given to the 0x1010400 magic number.
> -	 */
> -	for (i = 0; i <= 15; i++) {
> -		if (i != 6 && i != 7) {
> -			vsc73xx_write(vsc, VSC73XX_BLOCK_MEMINIT,
> -				      2,
> -				      0, 0x1010400 + i);
> -			mdelay(1);
> -		}
> -	}
> -	mdelay(30);
> -
> -	/* Clear MAC table */
> -	vsc73xx_write(vsc, VSC73XX_BLOCK_ANALYZER, 0,
> -		      VSC73XX_MACACCESS,
> -		      VSC73XX_MACACCESS_CMD_CLEAR_TABLE);
> -
> -	/* Clear VLAN table */
> -	vsc73xx_write(vsc, VSC73XX_BLOCK_ANALYZER, 0,
> -		      VSC73XX_VLANACCESS,
> -		      VSC73XX_VLANACCESS_VLAN_TBL_CMD_CLEAR_TABLE);
> -
> -	msleep(40);
> -
> -	/* Use 20KiB buffers on all ports on VSC7395
> -	 * The VSC7385 has 16KiB buffers and that is the
> -	 * default if we don't set this up explicitly.
> -	 * Port "31" is "all ports".
> -	 */
> -	if (IS_739X(vsc))
> -		vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, 0x1f,
> -			      VSC73XX_Q_MISC_CONF,
> -			      VSC73XX_Q_MISC_CONF_EXTENT_MEM);
> -
> -	/* Put all ports into reset until enabled */
> -	for (i = 0; i < 7; i++) {
> -		if (i == 5)
> -			continue;
> -		vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, 4,
> -			      VSC73XX_MAC_CFG, VSC73XX_MAC_CFG_RESET);
> -	}
> -
> -	/* MII delay, set both GTX and RX delay to 2 ns */
> -	vsc73xx_write(vsc, VSC73XX_BLOCK_SYSTEM, 0, VSC73XX_GMIIDELAY,
> -		      VSC73XX_GMIIDELAY_GMII0_GTXDELAY_2_0_NS |
> -		      VSC73XX_GMIIDELAY_GMII0_RXDELAY_2_0_NS);
> -	/* IP multicast flood mask (table 144) */
> -	vsc73xx_write(vsc, VSC73XX_BLOCK_ANALYZER, 0, VSC73XX_IFLODMSK,
> -		      0xff);
> -
> -	mdelay(50);
> -
> -	/*configure forward map to CPU <-> port only*/
> -	for (i = 0; i < vsc->ds->num_ports; i++)
> -		vsc->forward_map[i] = VSC73XX_SRCMASKS_PORTS_MASK & BIT(CPU_PORT);
> -	vsc->forward_map[CPU_PORT] = VSC73XX_SRCMASKS_PORTS_MASK & ~BIT(CPU_PORT);
> -
> -	/* Release reset from the internal PHYs */
> -	vsc73xx_write(vsc, VSC73XX_BLOCK_SYSTEM, 0, VSC73XX_GLORESET,
> -		      VSC73XX_GLORESET_PHY_RESET);
> -
> -	udelay(4);
> -
> -	return 0;

Try to make this code movement part of a separate patch. It's
distracting and makes it hard to see what really changed.

> +	return DSA_TAG_PROTO_VSC73XX_8021Q;
>  }
>  
>  static void vsc73xx_init_port(struct vsc73xx *vsc, int port)
> @@ -1078,6 +1027,417 @@ static void vsc73xx_port_stp_state_set(struct dsa_switch *ds, int port,
>  				    VSC73XX_SRCMASKS_PORTS_MASK, 0);
>  }
>  
> +static int
> +vsc73xx_port_wait_for_vlan_table_cmd(struct vsc73xx *vsc)
> +{
> +	u32 val;
> +	int ret, err;
> +
> +	ret = read_poll_timeout(vsc73xx_read, err,
> +				err < 0 || ((val & VSC73XX_VLANACCESS_VLAN_TBL_CMD_MASK) ==
> +					    VSC73XX_VLANACCESS_VLAN_TBL_CMD_IDLE),
> +				1000, 10000, false, vsc, VSC73XX_BLOCK_ANALYZER,
> +				0, VSC73XX_VLANACCESS, &val);
> +	if (ret)
> +		return ret;
> +	return err;
> +}
> +
> +static int
> +vsc73xx_port_read_vlan_table_entry(struct dsa_switch *ds, u16 vid, u8 *portmap)
> +{
> +	struct vsc73xx *vsc = ds->priv;
> +	u32 val;
> +	int ret;
> +
> +	if (vid > 4095)
> +		return -EPERM;

Unnecessary defensive programming.

> +	vsc73xx_write(vsc, VSC73XX_BLOCK_ANALYZER, 0, VSC73XX_VLANTIDX, vid);
> +	ret = vsc73xx_port_wait_for_vlan_table_cmd(vsc);
> +	if (ret)
> +		return ret;
> +	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ANALYZER, 0, VSC73XX_VLANACCESS,
> +			    VSC73XX_VLANACCESS_VLAN_TBL_CMD_MASK,
> +			    VSC73XX_VLANACCESS_VLAN_TBL_CMD_READ_ENTRY);
> +	ret = vsc73xx_port_wait_for_vlan_table_cmd(vsc);
> +	if (ret)
> +		return ret;
> +	vsc73xx_read(vsc, VSC73XX_BLOCK_ANALYZER, 0, VSC73XX_VLANACCESS, &val);
> +	*portmap = (val & VSC73XX_VLANACCESS_VLAN_PORT_MASK) >>
> +		   VSC73XX_VLANACCESS_VLAN_PORT_MASK_SHIFT;
> +	return 0;
> +}
> +
> +static int
> +vsc73xx_port_write_vlan_table_entry(struct dsa_switch *ds, u16 vid, u8 portmap)
> +{
> +	struct vsc73xx *vsc = ds->priv;
> +	int ret;
> +
> +	if (vid > 4095)
> +		return -EPERM;

Unnecessary defensive programming.

> +	vsc73xx_write(vsc, VSC73XX_BLOCK_ANALYZER, 0, VSC73XX_VLANTIDX, vid);
> +	ret = vsc73xx_port_wait_for_vlan_table_cmd(vsc);
> +	if (ret)
> +		return ret;
> +	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_ANALYZER, 0, VSC73XX_VLANACCESS,
> +			    VSC73XX_VLANACCESS_VLAN_TBL_CMD_MASK |
> +			    VSC73XX_VLANACCESS_VLAN_SRC_CHECK |
> +			    VSC73XX_VLANACCESS_VLAN_PORT_MASK,
> +			    VSC73XX_VLANACCESS_VLAN_TBL_CMD_WRITE_ENTRY |
> +			    VSC73XX_VLANACCESS_VLAN_SRC_CHECK |
> +			    (portmap <<
> +			     VSC73XX_VLANACCESS_VLAN_PORT_MASK_SHIFT));
> +	ret = vsc73xx_port_wait_for_vlan_table_cmd(vsc);
> +	if (ret)
> +		return ret;
> +	return 0;
> +}
> +
> +static int
> +vsc73xx_port_update_vlan_table(struct dsa_switch *ds, int port, u16 vid,
> +			       bool set)
> +{
> +	u8 portmap;
> +	int ret;
> +
> +	if (vid > 4095)
> +		return -EPERM;

Unnecessary defensive programming.

> +
> +	ret = vsc73xx_port_read_vlan_table_entry(ds, vid, &portmap);
> +	if (ret)
> +		return ret;
> +
> +	if (set)
> +		portmap |= BIT(port) | BIT(CPU_PORT);
> +	else
> +		portmap &= ~BIT(port);
> +
> +	if (portmap == BIT(CPU_PORT))
> +		portmap = 0;
> +
> +	ret = vsc73xx_port_write_vlan_table_entry(ds, vid, portmap);
> +
> +	return ret;

return vsc73xx_port_write_vlan_table_entry(...)

> +}
> +
> +static void
> +vsc73xx_port_set_vlan_conf(struct dsa_switch *ds, int port,
> +			   enum vsc73xx_port_vlan_conf port_vlan_conf)
> +{
> +	struct vsc73xx *vsc = ds->priv;
> +
> +	if (port_vlan_conf == VSC73XX_VLAN_UNAWARE) {
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_MAC_CFG,
> +				    VSC73XX_MAC_CFG_VLAN_AWR, 0);
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_MAC_CFG,
> +				    VSC73XX_MAC_CFG_VLAN_DBLAWR, 0);
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_CAT_VLAN_MISC,
> +				    VSC73XX_CAT_VLAN_MISC_VLAN_TCI_IGNORE_ENA,
> +				    VSC73XX_CAT_VLAN_MISC_VLAN_TCI_IGNORE_ENA);
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_CAT_VLAN_MISC,
> +				    VSC73XX_CAT_VLAN_MISC_VLAN_KEEP_TAG_ENA,
> +				    VSC73XX_CAT_VLAN_MISC_VLAN_KEEP_TAG_ENA);
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_CAT_DROP,
> +				    VSC73XX_CAT_DROP_TAGGED_ENA, 0);
> +	} else {
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_MAC_CFG,
> +				    VSC73XX_MAC_CFG_VLAN_AWR,
> +				    VSC73XX_MAC_CFG_VLAN_AWR);
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_CAT_DROP,
> +				    VSC73XX_CAT_DROP_TAGGED_ENA, 0);
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_CAT_DROP,
> +				    VSC73XX_CAT_DROP_UNTAGGED_ENA,
> +				    VSC73XX_CAT_DROP_UNTAGGED_ENA);
> +
> +		if (port_vlan_conf == VSC73XX_DOUBLE_VLAN_CPU_AWARE)
> +			vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +					    VSC73XX_MAC_CFG,
> +					    VSC73XX_MAC_CFG_VLAN_DBLAWR,
> +					    VSC73XX_MAC_CFG_VLAN_DBLAWR);
> +		else
> +			vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +					    VSC73XX_MAC_CFG,
> +					    VSC73XX_MAC_CFG_VLAN_DBLAWR, 0);
> +
> +		if (port_vlan_conf == VSC73XX_DOUBLE_VLAN_AWARE) {
> +			vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +					    VSC73XX_CAT_VLAN_MISC,
> +					    VSC73XX_CAT_VLAN_MISC_VLAN_TCI_IGNORE_ENA,
> +					    VSC73XX_CAT_VLAN_MISC_VLAN_TCI_IGNORE_ENA);
> +			vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +					    VSC73XX_CAT_VLAN_MISC,
> +					    VSC73XX_CAT_VLAN_MISC_VLAN_KEEP_TAG_ENA,
> +					    VSC73XX_CAT_VLAN_MISC_VLAN_KEEP_TAG_ENA);
> +			vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +					    VSC73XX_TXUPDCFG,
> +					    VSC73XX_TXUPDCFG_TX_INSERT_TAG, 0);
> +		} else {
> +			vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +					    VSC73XX_CAT_VLAN_MISC,
> +					    VSC73XX_CAT_VLAN_MISC_VLAN_TCI_IGNORE_ENA,
> +					    0);
> +			vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +					    VSC73XX_CAT_VLAN_MISC,
> +					    VSC73XX_CAT_VLAN_MISC_VLAN_KEEP_TAG_ENA,
> +					    0);
> +			vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +					    VSC73XX_TXUPDCFG,
> +					    VSC73XX_TXUPDCFG_TX_INSERT_TAG,
> +					    VSC73XX_TXUPDCFG_TX_INSERT_TAG);
> +		}
> +
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_TXUPDCFG,
> +				    VSC73XX_TXUPDCFG_TX_UNTAGGED_VID_ENA, 0);
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_TXUPDCFG,
> +				    VSC73XX_TXUPDCFG_TX_UNTAGGED_VID, 0);
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_CAT_PORT_VLAN,
> +				    VSC73XX_CAT_PORT_VLAN_VLAN_VID, 0);
> +	}
> +}
> +

I need some time to understand what is being done here.

> +static int vsc73xx_port_set_double_vlan_aware(struct dsa_switch *ds, int port)
> +{
> +	int i, ret;
> +
> +	if (port == CPU_PORT)
> +		vsc73xx_port_set_vlan_conf(ds, port,
> +					   VSC73XX_DOUBLE_VLAN_CPU_AWARE);
> +	else
> +		vsc73xx_port_set_vlan_conf(ds, port,
> +					   VSC73XX_DOUBLE_VLAN_AWARE);
> +
> +	for (i = 0; i <= 4095; i++) {

i < VLAN_N_VID

> +		ret = vsc73xx_port_update_vlan_table(ds, port, i, 0);
> +		if (ret)
> +			return ret;

Clearing the VLAN table absolutely does not belong in a function that
makes a port aware of double VLANs. And neither does it belong in a
function that changes VLAN awareness, but that's not part of this patch,
but 6/7. The bridge expects the VLAN table to be able to be populated
asynchronously relative to enabling/disabling it. The same for the
VLAN-aware FDB and MDB entries.

> +	}
> +	return ret;
> +}
> +
> +static int vsc73xx_vlan_set_untagged(struct dsa_switch *ds, int port, u16 vid,
> +				     bool port_vlan)
> +{
> +	struct vsc73xx *vsc = ds->priv;
> +	u16 vlan_no;
> +	u32 val;
> +
> +	vsc73xx_read(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_TXUPDCFG, &val);
> +
> +	if (port_vlan && (val & VSC73XX_TXUPDCFG_TX_UNTAGGED_VID_ENA)) {
> +		vsc73xx_read(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_TXUPDCFG,
> +			     &val);
> +		vlan_no = (val & VSC73XX_TXUPDCFG_TX_UNTAGGED_VID) >>
> +				VSC73XX_TXUPDCFG_TX_UNTAGGED_VID_SHIFT;
> +		if (!vid_is_dsa_8021q(vlan_no) && !vid_is_dsa_8021q(vid) &&
> +		    vlan_no != vid) {
> +			dev_warn(vsc->dev,
> +				 "Port %d can have only one untagged vid! Now is: %d.\n",
> +				 port, vlan_no);
> +				return -EPERM;

drop indentation by 1 level

don't return -EPERM, as that indicates a permissions-related issue to
the user process. Perhaps -EOPNOTSUPP.

use the extack for the message.. we now also have NL_SET_ERR_MSG_FMT()

> +		}
> +	}
> +
> +	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_CAT_DROP,
> +			    VSC73XX_CAT_DROP_UNTAGGED_ENA, 0);
> +	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_TXUPDCFG,
> +			    VSC73XX_TXUPDCFG_TX_UNTAGGED_VID_ENA,
> +			    VSC73XX_TXUPDCFG_TX_UNTAGGED_VID_ENA);
> +	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_TXUPDCFG,
> +			    VSC73XX_TXUPDCFG_TX_UNTAGGED_VID,
> +			    (vid << VSC73XX_TXUPDCFG_TX_UNTAGGED_VID_SHIFT) &
> +			     VSC73XX_TXUPDCFG_TX_UNTAGGED_VID);
> +	return 0;
> +}
> +
> +static int vsc73xx_vlan_set_pvid(struct dsa_switch *ds, int port, u16 vid,
> +				 bool port_vlan)
> +{
> +	struct dsa_port *dsa_port = dsa_to_port(ds, port);
> +	struct vsc73xx *vsc = ds->priv;
> +	u16 vlan_no;
> +	u32 val;
> +
> +	if (!dsa_port)
> +		return -EINVAL;
> +
> +	vsc73xx_read(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_CAT_PORT_VLAN, &val);
> +	vlan_no = val & VSC73XX_CAT_PORT_VLAN_VLAN_VID;
> +
> +	if (port_vlan && vlan_no && !vid_is_dsa_8021q(vlan_no) &&
> +	    !vid_is_dsa_8021q(vid) && vlan_no != vid) {
> +		dev_warn(vsc->dev,
> +			 "Port %d can have only one pvid! Now is: %d.\n",
> +			 port, vlan_no);
> +		return -EPERM;
> +	}
> +
> +	if (dsa_port_is_vlan_filtering(dsa_port))
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_CAT_VLAN_MISC,
> +				    VSC73XX_CAT_VLAN_MISC_VLAN_TCI_IGNORE_ENA,
> +				    0);
> +	else
> +		vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port,
> +				    VSC73XX_CAT_VLAN_MISC,
> +				    VSC73XX_CAT_VLAN_MISC_VLAN_TCI_IGNORE_ENA,
> +				    VSC73XX_CAT_VLAN_MISC_VLAN_TCI_IGNORE_ENA);
> +
> +	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_CAT_VLAN_MISC,
> +			    VSC73XX_CAT_VLAN_MISC_VLAN_KEEP_TAG_ENA,
> +			    VSC73XX_CAT_VLAN_MISC_VLAN_KEEP_TAG_ENA);
> +
> +	vsc73xx_update_bits(vsc, VSC73XX_BLOCK_MAC, port, VSC73XX_CAT_PORT_VLAN,
> +			    VSC73XX_CAT_PORT_VLAN_VLAN_VID,
> +			    vid & VSC73XX_CAT_PORT_VLAN_VLAN_VID);

Why would changing the PVID (what this function does) alter VLAN_TCI_IGNORE_ENA
and VLAN_KEEP_TAG_ENA?

> +	return 0;
> +}
> +
> +static int vsc73xx_tag_8021q_vlan_add(struct dsa_switch *ds, int port, u16 vid,
> +				      u16 flags)
> +{
> +	bool untagged = flags & BRIDGE_VLAN_INFO_UNTAGGED;
> +	bool pvid = flags & BRIDGE_VLAN_INFO_PVID;
> +	int ret;
> +
> +	if (untagged) {
> +		ret = vsc73xx_vlan_set_untagged(ds, port, vid, false);
> +		if (ret)
> +			return ret;
> +	}
> +	if (pvid) {
> +		ret = vsc73xx_vlan_set_pvid(ds, port, vid, false);
> +		if (ret)
> +			return ret;
> +	}
> +	ret = vsc73xx_port_update_vlan_table(ds, port, vid, 1);

return vsc73xx_port_update_vlan_table(...)

> +	if (ret)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int vsc73xx_tag_8021q_vlan_del(struct dsa_switch *ds, int port, u16 vid)
> +{
> +	return vsc73xx_port_update_vlan_table(ds, port, vid, 0);
> +}
> +
> +static int vsc73xx_setup(struct dsa_switch *ds)
> +{
> +	struct vsc73xx *vsc = ds->priv;
> +	int i, ret;
> +
> +	dev_info(vsc->dev, "set up the switch\n");
> +
> +	ds->vlan_filtering_is_global = false;

No reason to set this, it's false by default.

> +	ds->configure_vlan_while_not_filtering = false;

This is a legacy flag that should be set to true (default value) for all
drivers and then eliminated.

To check whether your implementation is doing the right thing, you must
remove this line, and make sure that after this configuration:

ip link add br0 type bridge vlan_filtering 0
ip link set swp0 master br0
bridge vlan add dev swp0 vid 100 pvid untagged

the VLAN-unaware forwarding of the switch is not affected. This means
that the PVID of the port that is committed to hardware (and thus, the
allowed destination port mask) must remain what the driver set it to,
while the bridge vlan_filtering option is not enabled. The hardware PVID
must only follow the bridge port PVID while in vlan_filtering=true mode.

> +
> +	/* Issue RESET */
> +	vsc73xx_write(vsc, VSC73XX_BLOCK_SYSTEM, 0, VSC73XX_GLORESET,
> +		      VSC73XX_GLORESET_MASTER_RESET);
> +	usleep_range(125, 200);
> +
> +	/* Initialize memory, initialize RAM bank 0..15 except 6 and 7
> +	 * This sequence appears in the
> +	 * VSC7385 SparX-G5 datasheet section 6.6.1
> +	 * VSC7395 SparX-G5e datasheet section 6.6.1
> +	 * "initialization sequence".
> +	 * No explanation is given to the 0x1010400 magic number.
> +	 */
> +	for (i = 0; i <= 15; i++) {
> +		if (i != 6 && i != 7) {
> +			vsc73xx_write(vsc, VSC73XX_BLOCK_MEMINIT,
> +				      2,
> +				      0, 0x1010400 + i);
> +			mdelay(1);
> +		}
> +	}
> +	mdelay(30);
> +
> +	/* Clear MAC table */
> +	vsc73xx_write(vsc, VSC73XX_BLOCK_ANALYZER, 0,
> +		      VSC73XX_MACACCESS,
> +		      VSC73XX_MACACCESS_CMD_CLEAR_TABLE);
> +
> +	/* Clear VLAN table */
> +	vsc73xx_write(vsc, VSC73XX_BLOCK_ANALYZER, 0,
> +		      VSC73XX_VLANACCESS,
> +		      VSC73XX_VLANACCESS_VLAN_TBL_CMD_CLEAR_TABLE);
> +
> +	msleep(40);
> +
> +	/* Use 20KiB buffers on all ports on VSC7395
> +	 * The VSC7385 has 16KiB buffers and that is the
> +	 * default if we don't set this up explicitly.
> +	 * Port "31" is "all ports".
> +	 */
> +	if (IS_739X(vsc))
> +		vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, 0x1f,
> +			      VSC73XX_Q_MISC_CONF,
> +			      VSC73XX_Q_MISC_CONF_EXTENT_MEM);
> +
> +	/* Put all ports into reset until enabled */
> +	for (i = 0; i < 7; i++) {
> +		if (i == 5)
> +			continue;
> +		vsc73xx_write(vsc, VSC73XX_BLOCK_MAC, 4,
> +			      VSC73XX_MAC_CFG, VSC73XX_MAC_CFG_RESET);
> +	}
> +
> +	/* MII delay, set both GTX and RX delay to 2 ns */
> +	vsc73xx_write(vsc, VSC73XX_BLOCK_SYSTEM, 0, VSC73XX_GMIIDELAY,
> +		      VSC73XX_GMIIDELAY_GMII0_GTXDELAY_2_0_NS |
> +		      VSC73XX_GMIIDELAY_GMII0_RXDELAY_2_0_NS);
> +	/* Ingess VLAN reception mask (table 145) */

s/ingess/ingress/

> +	vsc73xx_write(vsc, VSC73XX_BLOCK_ANALYZER, 0, VSC73XX_VLANMASK,
> +		      0x5f);
> +	/* IP multicast flood mask (table 144) */
> +	vsc73xx_write(vsc, VSC73XX_BLOCK_ANALYZER, 0, VSC73XX_IFLODMSK,
> +		      0xff);
> +
> +	mdelay(50);
> +
> +	for (i = 0; i < vsc->ds->num_ports; i++) {
> +		if (i == 5)
> +			continue;

dsa_switch_for_each_available_port()

> +		ret = vsc73xx_port_set_double_vlan_aware(ds, i);
> +		if (ret)
> +			return ret;

If ports are made VLAN-aware by default (including in standalone mode),
shouldn't this be reflected in ds->needs_standalone_vlan_filtering?

> +	}
> +
> +	rtnl_lock();
> +	ret = dsa_tag_8021q_register(ds, htons(ETH_P_8021Q));
> +	rtnl_unlock();
> +	if (ret)
> +		return ret;
> +
> +	/*configure forward map to CPU <-> port only*/

style: space after /* and before */ (also present in a few other places)

> +	for (i = 0; i < vsc->ds->num_ports; i++)
> +		vsc->forward_map[i] = VSC73XX_SRCMASKS_PORTS_MASK &
> +				      BIT(CPU_PORT);
> +	vsc->forward_map[CPU_PORT] = VSC73XX_SRCMASKS_PORTS_MASK &
> +				     ~BIT(CPU_PORT);
> +
> +	/* Release reset from the internal PHYs */
> +	vsc73xx_write(vsc, VSC73XX_BLOCK_SYSTEM, 0, VSC73XX_GLORESET,
> +		      VSC73XX_GLORESET_PHY_RESET);
> +
> +	udelay(4);
> +
> +	return 0;
> +}
> +
>  static const struct dsa_switch_ops vsc73xx_ds_ops = {
>  	.get_tag_protocol = vsc73xx_get_tag_protocol,
>  	.setup = vsc73xx_setup,
> @@ -1095,6 +1455,8 @@ static const struct dsa_switch_ops vsc73xx_ds_ops = {
>  	.port_change_mtu = vsc73xx_change_mtu,
>  	.port_max_mtu = vsc73xx_get_max_mtu,
>  	.port_stp_state_set = vsc73xx_port_stp_state_set,
> +	.tag_8021q_vlan_add = vsc73xx_tag_8021q_vlan_add,
> +	.tag_8021q_vlan_del = vsc73xx_tag_8021q_vlan_del,
>  };
>  
>  static int vsc73xx_gpio_get(struct gpio_chip *chip, unsigned int offset)
> diff --git a/include/net/dsa.h b/include/net/dsa.h
> index 75022cf771cf..2440df7ea6c9 100644
> --- a/include/net/dsa.h
> +++ b/include/net/dsa.h
> @@ -56,6 +56,7 @@ struct phylink_link_state;
>  #define DSA_TAG_PROTO_RTL8_4T_VALUE		25
>  #define DSA_TAG_PROTO_RZN1_A5PSW_VALUE		26
>  #define DSA_TAG_PROTO_LAN937X_VALUE		27
> +#define DSA_TAG_PROTO_VSC73XX_8021Q_VALUE	28
>  
>  enum dsa_tag_protocol {
>  	DSA_TAG_PROTO_NONE		= DSA_TAG_PROTO_NONE_VALUE,
> @@ -86,6 +87,7 @@ enum dsa_tag_protocol {
>  	DSA_TAG_PROTO_RTL8_4T		= DSA_TAG_PROTO_RTL8_4T_VALUE,
>  	DSA_TAG_PROTO_RZN1_A5PSW	= DSA_TAG_PROTO_RZN1_A5PSW_VALUE,
>  	DSA_TAG_PROTO_LAN937X		= DSA_TAG_PROTO_LAN937X_VALUE,
> +	DSA_TAG_PROTO_VSC73XX_8021Q	= DSA_TAG_PROTO_VSC73XX_8021Q_VALUE,
>  };
>  
>  struct dsa_switch;
> diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
> index 8e698bea99a3..e59360071c67 100644
> --- a/net/dsa/Kconfig
> +++ b/net/dsa/Kconfig
> @@ -166,6 +166,12 @@ config NET_DSA_TAG_TRAILER
>  	  Say Y or M if you want to enable support for tagging frames at
>  	  with a trailed. e.g. Marvell 88E6060.
>  
> +config NET_DSA_TAG_VSC73XX_8021Q
> +	tristate "Tag driver for Microchip/Vitesse VSC73xx family of switches, using VLAN"
> +	help
> +	  Say Y or M if you want to enable support for tagging frames with a
> +	  custom VLAN-based header.
> +

Separate patches for the tagger and for the driver infrastructure please.
It's hard to review.

Also, there's some very strange splitting between this patch and 6/7
("net: dsa: vsc73xx: Add vlan filtering"). I would have expected that to
contain the basic infrastructure (thus appearing first), then the
driver-side tag_8021q infra, then the tagger. It's impossible for me to
comment on things that have to do with VLAN infrastructure when it's
split between 2 patches.