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net: gemini: Look up L3 maxlen from table

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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.

Acked-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Linus Walleij 2018-07-11 21:32:41 +02:00 • committed by David S. Miller
parent 750c721ee0
commit cedca41801
1 changed files with 46 additions and 15 deletions
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61
drivers/net/ethernet/cortina/gemini.c
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@ -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)
/* 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;
};
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)
{
/* index = CONFIG_MAXLEN_XXX values */
static const int max_len[8] = {
1536, 1518, 1522, 1542,
9212, 10236, 1518, 1518
};
int i, n = 5;
const struct gmac_max_framelen *maxlen;
int maxtot;
int i;
max_l3_len += ETH_HLEN + VLAN_HLEN;
maxtot = max_l3_len + ETH_HLEN + VLAN_HLEN;
if (max_l3_len > max_len[n])
return -1;
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)