Re: [PATCH 1/3] net: dsa: mv88e6xxx: add debugfs interface for VTU

From: Andrew Lunn
Date: Fri Jun 26 2015 - 10:10:50 EST


On Tue, Jun 23, 2015 at 05:46:08PM -0400, Vivien Didelot wrote:
> Implement the Get Next operation for the VLAN Table Unit, and a "vtu"
> debugfs file to dump the hardware VLANs.
>
> A populated VTU can look like this:
>
> # cat /sys/kernel/debug/dsa0/vtu
> VID FID SID P0 P1 P2 P3 P4 P5 P6
> 550 562 0 x x x u x t x
> 1000 1012 0 x x t x x t x
> 1200 1212 0 x x t x t t x


Hi Vivien

Could you make this more generic and make use of ps->num_ports? Not
all switches have 7 ports.

>
> Signed-off-by: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>
> ---
> drivers/net/dsa/mv88e6xxx.c | 138 ++++++++++++++++++++++++++++++++++++++++++++
> drivers/net/dsa/mv88e6xxx.h | 24 ++++++++
> 2 files changed, 162 insertions(+)
>
> diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
> index 8c130c0..0dce8e8 100644
> --- a/drivers/net/dsa/mv88e6xxx.c
> +++ b/drivers/net/dsa/mv88e6xxx.c
> @@ -1366,6 +1366,81 @@ static void mv88e6xxx_bridge_work(struct work_struct *work)
> }
> }
>
> +static int _mv88e6xxx_vtu_wait(struct dsa_switch *ds)
> +{
> + return _mv88e6xxx_wait(ds, REG_GLOBAL, GLOBAL_VTU_OP,
> + GLOBAL_VTU_OP_BUSY);
> +}
> +
> +static int _mv88e6xxx_vtu_cmd(struct dsa_switch *ds, u16 op)
> +{
> + int ret;
> +
> + ret = _mv88e6xxx_reg_write(ds, REG_GLOBAL, GLOBAL_VTU_OP, op);
> + if (ret < 0)
> + return ret;
> +
> + return _mv88e6xxx_vtu_wait(ds);
> +}
> +
> +static int _mv88e6xxx_vtu_getnext(struct dsa_switch *ds, u16 vid,
> + struct mv88e6xxx_vtu_entry *entry)
> +{
> + int ret, i;
> +
> + ret = _mv88e6xxx_vtu_wait(ds);
> + if (ret < 0)
> + return ret;
> +
> + ret = _mv88e6xxx_reg_write(ds, REG_GLOBAL, GLOBAL_VTU_VID,
> + vid & GLOBAL_VTU_VID_MASK);
> + if (ret < 0)
> + return ret;
> +
> + ret = _mv88e6xxx_vtu_cmd(ds, GLOBAL_VTU_OP_VTU_GET_NEXT);
> + if (ret < 0)
> + return ret;
> +
> + ret = _mv88e6xxx_reg_read(ds, REG_GLOBAL, GLOBAL_VTU_VID);
> + if (ret < 0)
> + return ret;
> +
> + entry->vid = ret & GLOBAL_VTU_VID_MASK;
> + entry->valid = !!(ret & GLOBAL_VTU_VID_VALID);
> +
> + if (entry->valid) {
> + /* Ports 0-3, offsets 0, 4, 8, 12 */
> + ret = _mv88e6xxx_reg_read(ds, REG_GLOBAL, GLOBAL_VTU_DATA_0_3);
> + if (ret < 0)
> + return ret;
> +
> + for (i = 0; i < 4; ++i)
> + entry->tags[i] = (ret >> (i * 4)) & 3;
> +
> + /* Ports 4-6, offsets 0, 4, 8 */
> + ret = _mv88e6xxx_reg_read(ds, REG_GLOBAL, GLOBAL_VTU_DATA_4_7);
> + if (ret < 0)
> + return ret;
> +
> + for (i = 4; i < 7; ++i)
> + entry->tags[i] = (ret >> ((i - 4) * 4)) & 3;
> +
> + ret = _mv88e6xxx_reg_read(ds, REG_GLOBAL, GLOBAL_VTU_FID);
> + if (ret < 0)
> + return ret;
> +
> + entry->fid = ret & GLOBAL_VTU_FID_MASK;
> +
> + ret = _mv88e6xxx_reg_read(ds, REG_GLOBAL, GLOBAL_VTU_SID);
> + if (ret < 0)
> + return ret;
> +
> + entry->sid = ret & GLOBAL_VTU_SID_MASK;

As you point out in the header file, not all switches have FID and
VID. A quick look at DSDT suggests for both FID and SID:

DEV_88E6097_FAMILY | DEV_88E6165_FAMILY | DEV_88E6351_FAMILY | DEV_88E6352_FAMILY

Please limit access to these registers to just these families.

> + }
> +
> + return 0;
> +}
> +
> static int mv88e6xxx_setup_port(struct dsa_switch *ds, int port)
> {
> struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
> @@ -1739,6 +1814,66 @@ static const struct file_operations mv88e6xxx_atu_fops = {
> .owner = THIS_MODULE,
> };
>
> +static int mv88e6xxx_vtu_show(struct seq_file *s, void *p)
> +{
> + struct dsa_switch *ds = s->private;
> + struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
> + int vid = 0xfff; /* find the first or lowest VID */
> + int ret = 0;
> + int port;
> +
> + seq_puts(s, "VID FID SID P0 P1 P2 P3 P4 P5 P6\n");
> + mutex_lock(&ps->smi_mutex);
> +
> + do {
> + struct mv88e6xxx_vtu_entry next = { 0 };
> +
> + ret = _mv88e6xxx_vtu_getnext(ds, vid, &next);
> + if (ret < 0)
> + goto unlock;
> +
> + if (!next.valid)
> + break;
> +
> + seq_printf(s, "%-4d %-4d %-2d ", next.vid, next.fid, next.sid);
> + for (port = 0; port < 7; ++port) {
> + u8 tag = next.tags[port];
> +
> + if (tag == GLOBAL_VTU_DATA_MEMBER_TAG_UNMODIFIED)
> + seq_puts(s, " -");
> + else if (tag == GLOBAL_VTU_DATA_MEMBER_TAG_UNTAGGED)
> + seq_puts(s, " u");
> + else if (tag == GLOBAL_VTU_DATA_MEMBER_TAG_TAGGED)
> + seq_puts(s, " t");
> + else if (tag == GLOBAL_VTU_DATA_MEMBER_TAG_NON_MEMBER)
> + seq_puts(s, " x");
> + else
> + seq_puts(s, " ?"); /* unlikely */

Maybe use a switch statememt?

Thanks
Andrew
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