| Message ID | 20180704183324.10605-1-linus.walleij@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [net-next,1/5,v2] net: gemini: Look up L3 maxlen from table | expand |
On Wed, Jul 04, 2018 at 08:33:20PM +0200, Linus Walleij wrote: > The code to calculate the hardware register enumerator > for the maximum L3 length isn't entirely simple to read. > Use the existing defines and rewrite the function into a > table look-up. A matter of habit. ;-) I think that if you just renamed 'n' to 'best_index' and avoided reusing 'max_l3_len' (as you already did) the idea could be made more obvious without expading the code to twice the lines. The max_len[] array in the original code documents how the HW reacts to a specific setting. Acked-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Best Regards, Michał Mirosław > > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > ChangeLog v1->v2: > - No changes, just resending with the rest. > --- > drivers/net/ethernet/cortina/gemini.c | 61 ++++++++++++++++++++------- > 1 file changed, 46 insertions(+), 15 deletions(-) > > diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c > index 6d7404f66f84..8fc31723f700 100644 > --- a/drivers/net/ethernet/cortina/gemini.c > +++ b/drivers/net/ethernet/cortina/gemini.c > @@ -401,26 +401,57 @@ static int gmac_setup_phy(struct net_device *netdev) > return 0; > } > > -static int gmac_pick_rx_max_len(int max_l3_len) > -{ > - /* index = CONFIG_MAXLEN_XXX values */ > - static const int max_len[8] = { > - 1536, 1518, 1522, 1542, > - 9212, 10236, 1518, 1518 > - }; > - int i, n = 5; > +/* The maximum frame length is not logically enumerated in the > + * hardware, so we do a table lookup to find the applicable max > + * frame length. > + */ > +struct gmac_max_framelen { > + unsigned int max_l3_len; > + u8 val; > +}; > > - max_l3_len += ETH_HLEN + VLAN_HLEN; > +static const struct gmac_max_framelen gmac_maxlens[] = { > + { > + .max_l3_len = 1518, > + .val = CONFIG0_MAXLEN_1518, > + }, > + { > + .max_l3_len = 1522, > + .val = CONFIG0_MAXLEN_1522, > + }, > + { > + .max_l3_len = 1536, > + .val = CONFIG0_MAXLEN_1536, > + }, > + { > + .max_l3_len = 1542, > + .val = CONFIG0_MAXLEN_1542, > + }, > + { > + .max_l3_len = 9212, > + .val = CONFIG0_MAXLEN_9k, > + }, > + { > + .max_l3_len = 10236, > + .val = CONFIG0_MAXLEN_10k, > + }, > +}; > + > +static int gmac_pick_rx_max_len(unsigned int max_l3_len) > +{ > + const struct gmac_max_framelen *maxlen; > + int maxtot; > + int i; > > - if (max_l3_len > max_len[n]) > - return -1; > + maxtot = max_l3_len + ETH_HLEN + VLAN_HLEN; > > - for (i = 0; i < 5; i++) { > - if (max_len[i] >= max_l3_len && max_len[i] < max_len[n]) > - n = i; > + for (i = 0; i < ARRAY_SIZE(gmac_maxlens); i++) { > + maxlen = &gmac_maxlens[i]; > + if (maxtot <= maxlen->max_l3_len) > + return maxlen->val; > } > > - return n; > + return -1; > } > > static int gmac_init(struct net_device *netdev) > -- > 2.17.1 >
diff --git a/drivers/net/ethernet/cortina/gemini.c b/drivers/net/ethernet/cortina/gemini.c index 6d7404f66f84..8fc31723f700 100644 --- a/drivers/net/ethernet/cortina/gemini.c +++ b/drivers/net/ethernet/cortina/gemini.c @@ -401,26 +401,57 @@ static int gmac_setup_phy(struct net_device *netdev) return 0; } -static int gmac_pick_rx_max_len(int max_l3_len) -{ - /* index = CONFIG_MAXLEN_XXX values */ - static const int max_len[8] = { - 1536, 1518, 1522, 1542, - 9212, 10236, 1518, 1518 - }; - int i, n = 5; +/* The maximum frame length is not logically enumerated in the + * hardware, so we do a table lookup to find the applicable max + * frame length. + */ +struct gmac_max_framelen { + unsigned int max_l3_len; + u8 val; +}; - max_l3_len += ETH_HLEN + VLAN_HLEN; +static const struct gmac_max_framelen gmac_maxlens[] = { + { + .max_l3_len = 1518, + .val = CONFIG0_MAXLEN_1518, + }, + { + .max_l3_len = 1522, + .val = CONFIG0_MAXLEN_1522, + }, + { + .max_l3_len = 1536, + .val = CONFIG0_MAXLEN_1536, + }, + { + .max_l3_len = 1542, + .val = CONFIG0_MAXLEN_1542, + }, + { + .max_l3_len = 9212, + .val = CONFIG0_MAXLEN_9k, + }, + { + .max_l3_len = 10236, + .val = CONFIG0_MAXLEN_10k, + }, +}; + +static int gmac_pick_rx_max_len(unsigned int max_l3_len) +{ + const struct gmac_max_framelen *maxlen; + int maxtot; + int i; - if (max_l3_len > max_len[n]) - return -1; + maxtot = max_l3_len + ETH_HLEN + VLAN_HLEN; - for (i = 0; i < 5; i++) { - if (max_len[i] >= max_l3_len && max_len[i] < max_len[n]) - n = i; + for (i = 0; i < ARRAY_SIZE(gmac_maxlens); i++) { + maxlen = &gmac_maxlens[i]; + if (maxtot <= maxlen->max_l3_len) + return maxlen->val; } - return n; + return -1; } static int gmac_init(struct net_device *netdev)
The code to calculate the hardware register enumerator for the maximum L3 length isn't entirely simple to read. Use the existing defines and rewrite the function into a table look-up. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ChangeLog v1->v2: - No changes, just resending with the rest. --- drivers/net/ethernet/cortina/gemini.c | 61 ++++++++++++++++++++------- 1 file changed, 46 insertions(+), 15 deletions(-) -- 2.17.1