From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 21353C433F5 for ; Sun, 13 Mar 2022 08:36:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233828AbiCMIhy (ORCPT ); Sun, 13 Mar 2022 04:37:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42224 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233553AbiCMIhy (ORCPT ); Sun, 13 Mar 2022 04:37:54 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1BCA11AC2A5 for ; Sun, 13 Mar 2022 00:36:46 -0800 (PST) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1nTJiW-00072z-4v for linux-can@vger.kernel.org; Sun, 13 Mar 2022 09:36:44 +0100 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id 4C48949A9A for ; Sun, 13 Mar 2022 08:36:41 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id 0813D49A7F; Sun, 13 Mar 2022 08:36:41 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 8d23b23d; Sun, 13 Mar 2022 08:36:40 +0000 (UTC) From: Marc Kleine-Budde To: linux-can@vger.kernel.org Cc: kernel@pengutronix.de, Manivannan Sadhasivam , Thomas Kopp , Marc Kleine-Budde Subject: [can-next-rfc 02/12] can: mcp251xfd: ram: add helper function for runtime ring size calculation Date: Sun, 13 Mar 2022 09:36:30 +0100 Message-Id: <20220313083640.501791-3-mkl@pengutronix.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220313083640.501791-1-mkl@pengutronix.de> References: <20220313083640.501791-1-mkl@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-can@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-can@vger.kernel.org This patch adds a helper function to calculate the ring configuration of the controller based on various constraints, like available RAM, size of RX and TX objects, CAN-mode, number of FIFOs and FIFO depth. Signed-off-by: Marc Kleine-Budde --- drivers/net/can/spi/mcp251xfd/Makefile | 1 + drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.c | 97 +++++++++++++++++++ drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.h | 57 +++++++++++ 3 files changed, 155 insertions(+) create mode 100644 drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.c create mode 100644 drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.h diff --git a/drivers/net/can/spi/mcp251xfd/Makefile b/drivers/net/can/spi/mcp251xfd/Makefile index a83d685d64e0..10c4f886d1f7 100644 --- a/drivers/net/can/spi/mcp251xfd/Makefile +++ b/drivers/net/can/spi/mcp251xfd/Makefile @@ -6,6 +6,7 @@ mcp251xfd-objs := mcp251xfd-objs += mcp251xfd-chip-fifo.o mcp251xfd-objs += mcp251xfd-core.o mcp251xfd-objs += mcp251xfd-crc16.o +mcp251xfd-objs += mcp251xfd-ram.o mcp251xfd-objs += mcp251xfd-regmap.o mcp251xfd-objs += mcp251xfd-ring.o mcp251xfd-objs += mcp251xfd-rx.o diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.c new file mode 100644 index 000000000000..6e7293e50d2c --- /dev/null +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// mcp251xfd - Microchip MCP251xFD Family CAN controller driver +// +// Copyright (c) 2021, 2022 Pengutronix, +// Marc Kleine-Budde +// + +#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, u8 val) +{ + u8 fifo_num = obj->fifo_num; + u8 ret = 0, i; + + val = can_ram_clamp(config, obj, val); + + 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 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, 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_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, num_rx); + layout->max_tx = can_ram_rounddown_pow_of_two(config, &config->tx, num_tx); + + /* cur CAN */ + + if (ring) { + num_rx = can_ram_rounddown_pow_of_two(config, &config->rx, ring->rx_pending); + + 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); + + layout->cur_rx = num_rx; + layout->cur_tx = num_tx; + } else { + layout->cur_rx = layout->default_rx; + layout->cur_tx = layout->default_tx; + } +} diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.h b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.h new file mode 100644 index 000000000000..c998a033c9cb --- /dev/null +++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-ram.h @@ -0,0 +1,57 @@ +/* SPDX-License-Identifier: GPL-2.0 + * + * mcp251xfd - Microchip MCP251xFD Family CAN controller driver + * + * Copyright (c) 2021, 2022 Pengutronix, + * Marc Kleine-Budde + */ + +#ifndef _MCP251XFD_RAM_H +#define _MCP251XFD_RAM_H + +#include + +#define CAN_RAM_NUM_MAX (-1) + +enum can_ram_mode { + CAN_RAM_MODE_CAN, + CAN_RAM_MODE_CANFD, + __CAN_RAM_MODE_MAX +}; + +struct can_ram_obj_config { + u8 size[__CAN_RAM_MODE_MAX]; + + u8 def[__CAN_RAM_MODE_MAX]; + u8 min; + u8 max; + + u8 fifo_num; + u8 fifo_depth_min; +}; + +struct can_ram_config { + const struct can_ram_obj_config rx; + const struct can_ram_obj_config tx; + + u16 size; + u8 fifo_depth; +}; + +struct can_ram_layout { + u8 default_rx; + u8 default_tx; + + u8 max_rx; + u8 max_tx; + + u8 cur_rx; + u8 cur_tx; +}; + +void can_ram_get_layout(struct can_ram_layout *layout, + const struct can_ram_config *config, + const struct ethtool_ringparam *ring, + const bool fd_mode); + +#endif -- 2.35.1