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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 | // SPDX-License-Identifier: GPL-2.0 // // mcp251xfd - Microchip MCP251xFD Family CAN controller driver // // Copyright (c) 2021, 2022 Pengutronix, // Marc Kleine-Budde <kernel@pengutronix.de> // #include "mcp251xfd-ram.h" static inline u8 can_ram_clamp(const struct can_ram_config *config, const struct can_ram_obj_config *obj, u8 val) { u8 max; max = min_t(u8, obj->max, obj->fifo_num * config->fifo_depth); return clamp(val, obj->min, max); } static u8 can_ram_rounddown_pow_of_two(const struct can_ram_config *config, 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; n = min_t(u8, rounddown_pow_of_two(val), config->fifo_depth); /* skip small FIFOs */ if (n < obj->fifo_depth_min) return ret; ret += n; val -= n; } return ret; } 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; u16 ram_free; /* default CAN */ num_tx = config->tx.def[fd_mode]; 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, 0, num_rx); layout->default_tx = num_tx; /* MAX CAN */ ram_free = config->size; ram_free -= config->tx.size[fd_mode] * config->tx.min; num_rx = ram_free / config->rx.size[fd_mode]; ram_free = config->size; 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, 0, num_rx); layout->max_tx = can_ram_rounddown_pow_of_two(config, &config->tx, 0, num_tx); /* cur CAN */ if (ring) { 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, 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; } } |