| Message ID | 20241003212301.1339647-1-CFSworks@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 41378cfdc47fdbfbf4358b85546f7c2f5f671534 |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: dsa: bcm_sf2: fix crossbar port bitwidth logic | expand |
On 10/3/24 14:23, Sam Edwards wrote: > The SF2 crossbar register is a packed bitfield, giving the index of the > external port selected for each of the internal ports. On BCM4908 (the > only currently-supported switch family with a crossbar), there are 2 > internal ports and 3 external ports, so there are 2 bits per internal > port. > > The driver currently conflates the "bits per port" and "number of ports" > concepts, lumping both into the `num_crossbar_int_ports` field. Since it > is currently only possible for either of these counts to have a value of > 2, there is no behavioral error resulting from this situation for now. > > Make the code more readable (and support the future possibility of > larger crossbars) by adding a `num_crossbar_ext_bits` field to represent > the "bits per port" count and relying on this where appropriate instead. > > Signed-off-by: Sam Edwards <CFSworks@gmail.com> Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Thu, 3 Oct 2024 14:23:01 -0700 you wrote: > The SF2 crossbar register is a packed bitfield, giving the index of the > external port selected for each of the internal ports. On BCM4908 (the > only currently-supported switch family with a crossbar), there are 2 > internal ports and 3 external ports, so there are 2 bits per internal > port. > > The driver currently conflates the "bits per port" and "number of ports" > concepts, lumping both into the `num_crossbar_int_ports` field. Since it > is currently only possible for either of these counts to have a value of > 2, there is no behavioral error resulting from this situation for now. > > [...] Here is the summary with links: - net: dsa: bcm_sf2: fix crossbar port bitwidth logic https://git.kernel.org/netdev/net-next/c/41378cfdc47f You are awesome, thank you!
diff --git a/drivers/net/dsa/bcm_sf2.c b/drivers/net/dsa/bcm_sf2.c index 0e663ec0c12a..3ae794a30ace 100644 --- a/drivers/net/dsa/bcm_sf2.c +++ b/drivers/net/dsa/bcm_sf2.c @@ -513,12 +513,12 @@ static void bcm_sf2_crossbar_setup(struct bcm_sf2_priv *priv) u32 reg; int i; - mask = BIT(priv->num_crossbar_int_ports) - 1; + mask = BIT(priv->num_crossbar_ext_bits) - 1; reg = reg_readl(priv, REG_CROSSBAR); switch (priv->type) { case BCM4908_DEVICE_ID: - shift = CROSSBAR_BCM4908_INT_P7 * priv->num_crossbar_int_ports; + shift = CROSSBAR_BCM4908_INT_P7 * priv->num_crossbar_ext_bits; reg &= ~(mask << shift); if (0) /* FIXME */ reg |= CROSSBAR_BCM4908_EXT_SERDES << shift; @@ -536,7 +536,7 @@ static void bcm_sf2_crossbar_setup(struct bcm_sf2_priv *priv) reg = reg_readl(priv, REG_CROSSBAR); for (i = 0; i < priv->num_crossbar_int_ports; i++) { - shift = i * priv->num_crossbar_int_ports; + shift = i * priv->num_crossbar_ext_bits; dev_dbg(dev, "crossbar int port #%d - ext port #%d\n", i, (reg >> shift) & mask); @@ -1260,6 +1260,7 @@ struct bcm_sf2_of_data { unsigned int core_reg_align; unsigned int num_cfp_rules; unsigned int num_crossbar_int_ports; + unsigned int num_crossbar_ext_bits; }; static const u16 bcm_sf2_4908_reg_offsets[] = { @@ -1288,6 +1289,7 @@ static const struct bcm_sf2_of_data bcm_sf2_4908_data = { .reg_offsets = bcm_sf2_4908_reg_offsets, .num_cfp_rules = 256, .num_crossbar_int_ports = 2, + .num_crossbar_ext_bits = 2, }; /* Register offsets for the SWITCH_REG_* block */ @@ -1399,6 +1401,7 @@ static int bcm_sf2_sw_probe(struct platform_device *pdev) priv->core_reg_align = data->core_reg_align; priv->num_cfp_rules = data->num_cfp_rules; priv->num_crossbar_int_ports = data->num_crossbar_int_ports; + priv->num_crossbar_ext_bits = data->num_crossbar_ext_bits; priv->rcdev = devm_reset_control_get_optional_exclusive(&pdev->dev, "switch"); diff --git a/drivers/net/dsa/bcm_sf2.h b/drivers/net/dsa/bcm_sf2.h index f95f4880b69e..4fda075a3449 100644 --- a/drivers/net/dsa/bcm_sf2.h +++ b/drivers/net/dsa/bcm_sf2.h @@ -75,6 +75,7 @@ struct bcm_sf2_priv { unsigned int core_reg_align; unsigned int num_cfp_rules; unsigned int num_crossbar_int_ports; + unsigned int num_crossbar_ext_bits; /* spinlock protecting access to the indirect registers */ spinlock_t indir_lock;
The SF2 crossbar register is a packed bitfield, giving the index of the external port selected for each of the internal ports. On BCM4908 (the only currently-supported switch family with a crossbar), there are 2 internal ports and 3 external ports, so there are 2 bits per internal port. The driver currently conflates the "bits per port" and "number of ports" concepts, lumping both into the `num_crossbar_int_ports` field. Since it is currently only possible for either of these counts to have a value of 2, there is no behavioral error resulting from this situation for now. Make the code more readable (and support the future possibility of larger crossbars) by adding a `num_crossbar_ext_bits` field to represent the "bits per port" count and relying on this where appropriate instead. Signed-off-by: Sam Edwards <CFSworks@gmail.com> --- drivers/net/dsa/bcm_sf2.c | 9 ++++++--- drivers/net/dsa/bcm_sf2.h | 1 + 2 files changed, 7 insertions(+), 3 deletions(-)