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can: mcp251xfd: ram: coalescing support

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This patch adds support for coalescing to the RAM layout calculation.

Link: https://lore.kernel.org/20220313083640.501791-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This commit is contained in:
Marc Kleine-Budde 2021-02-16 11:46:16 +01:00
parent a1439a5add
commit b8123d94f5
2 changed files with 68 additions and 7 deletions
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70
drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.c
View File

@ -20,13 +20,26 @@ static inline u8 can_ram_clamp(const struct can_ram_config *config,
static u8
can_ram_rounddown_pow_of_two(const struct can_ram_config *config,
const struct can_ram_obj_config *obj, u8 val)
const struct can_ram_obj_config *obj,
const u8 coalesce, u8 val)
{
u8 fifo_num = obj->fifo_num;
u8 ret = 0, i;
val = can_ram_clamp(config, obj, val);
if (coalesce) {
/* Use 1st FIFO for coalescing, if requested.
*
* Either use complete FIFO (and FIFO Full IRQ) for
* coalescing or only half of FIFO (FIFO Half Full
* IRQ) and use remaining half for normal objects.
*/
ret = min_t(u8, coalesce * 2, config->fifo_depth);
val -= ret;
fifo_num--;
}
for (i = 0; i < fifo_num && val; i++) {
u8 n;
@ -47,6 +60,7 @@ can_ram_rounddown_pow_of_two(const struct can_ram_config *config,
void can_ram_get_layout(struct can_ram_layout *layout,
const struct can_ram_config *config,
const struct ethtool_ringparam *ring,
const struct ethtool_coalesce *ec,
const bool fd_mode)
{
u8 num_rx, num_tx;
@ -55,14 +69,14 @@ void can_ram_get_layout(struct can_ram_layout *layout,
/* default CAN */
num_tx = config->tx.def[fd_mode];
num_tx = can_ram_rounddown_pow_of_two(config, &config->tx, num_tx);
num_tx = can_ram_rounddown_pow_of_two(config, &config->tx, 0, num_tx);
ram_free = config->size;
ram_free -= config->tx.size[fd_mode] * num_tx;
num_rx = ram_free / config->rx.size[fd_mode];
layout->default_rx = can_ram_rounddown_pow_of_two(config, &config->rx, num_rx);
layout->default_rx = can_ram_rounddown_pow_of_two(config, &config->rx, 0, num_rx);
layout->default_tx = num_tx;
/* MAX CAN */
@ -75,23 +89,65 @@ void can_ram_get_layout(struct can_ram_layout *layout,
ram_free -= config->rx.size[fd_mode] * config->rx.min;
num_tx = ram_free / config->tx.size[fd_mode];
layout->max_rx = can_ram_rounddown_pow_of_two(config, &config->rx, num_rx);
layout->max_tx = can_ram_rounddown_pow_of_two(config, &config->tx, num_tx);
layout->max_rx = can_ram_rounddown_pow_of_two(config, &config->rx, 0, num_rx);
layout->max_tx = can_ram_rounddown_pow_of_two(config, &config->tx, 0, num_tx);
/* cur CAN */
if (ring) {
num_rx = can_ram_rounddown_pow_of_two(config, &config->rx, ring->rx_pending);
u8 num_rx_coalesce = 0, num_tx_coalesce = 0;
num_rx = can_ram_rounddown_pow_of_two(config, &config->rx, 0, ring->rx_pending);
/* The ethtool doc says:
* To disable coalescing, set usecs = 0 and max_frames = 1.
*/
if (ec && !(ec->rx_coalesce_usecs_irq == 0 &&
ec->rx_max_coalesced_frames_irq == 1)) {
u8 max;
/* use only max half of available objects for coalescing */
max = min_t(u8, num_rx / 2, config->fifo_depth);
num_rx_coalesce = clamp(ec->rx_max_coalesced_frames_irq,
(u32)config->rx.fifo_depth_coalesce_min,
(u32)max);
num_rx_coalesce = rounddown_pow_of_two(num_rx_coalesce);
num_rx = can_ram_rounddown_pow_of_two(config, &config->rx,
num_rx_coalesce, num_rx);
}
ram_free = config->size - config->rx.size[fd_mode] * num_rx;
num_tx = ram_free / config->tx.size[fd_mode];
num_tx = min_t(u8, ring->tx_pending, num_tx);
num_tx = can_ram_rounddown_pow_of_two(config, &config->tx, num_tx);
num_tx = can_ram_rounddown_pow_of_two(config, &config->tx, 0, num_tx);
/* The ethtool doc says:
* To disable coalescing, set usecs = 0 and max_frames = 1.
*/
if (ec && !(ec->tx_coalesce_usecs_irq == 0 &&
ec->tx_max_coalesced_frames_irq == 1)) {
u8 max;
/* use only max half of available objects for coalescing */
max = min_t(u8, num_tx / 2, config->fifo_depth);
num_tx_coalesce = clamp(ec->tx_max_coalesced_frames_irq,
(u32)config->tx.fifo_depth_coalesce_min,
(u32)max);
num_tx_coalesce = rounddown_pow_of_two(num_tx_coalesce);
num_tx = can_ram_rounddown_pow_of_two(config, &config->tx,
num_tx_coalesce, num_tx);
}
layout->cur_rx = num_rx;
layout->cur_tx = num_tx;
layout->rx_coalesce = num_rx_coalesce;
layout->tx_coalesce = num_tx_coalesce;
} else {
layout->cur_rx = layout->default_rx;
layout->cur_tx = layout->default_tx;
layout->rx_coalesce = 0;
layout->tx_coalesce = 0;
}
}

5
drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.h
View File

@ -28,6 +28,7 @@ struct can_ram_obj_config {
u8 fifo_num;
u8 fifo_depth_min;
u8 fifo_depth_coalesce_min;
};
struct can_ram_config {
@ -47,11 +48,15 @@ struct can_ram_layout {
u8 cur_rx;
u8 cur_tx;
u8 rx_coalesce;
u8 tx_coalesce;
};
void can_ram_get_layout(struct can_ram_layout *layout,
const struct can_ram_config *config,
const struct ethtool_ringparam *ring,
const struct ethtool_coalesce *ec,
const bool fd_mode);
#endif