From patchwork Fri Jan 10 14:45:22 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 13934928 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DDFA6E7719C for ; Fri, 10 Jan 2025 15:11:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References:Message-Id :MIME-Version:Subject:Date:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8Utnf8VBBNuThPOfi5eYwwwYcrEj23kgMBTDJU1Tu/w=; b=s7F9lgjmeVKNns lqFRN25gS4jTymQ/tdzVUJOakNMaIuQFPblisEnY3CxoK5Iga2F4wVTLPbK9EASXUk+qbASlnBKuc MxO+rWotEcairPvl25jRVXP+zkSGV2Mv052a2vGLML3rPYuzZrK/hETiUoCTVV0DphNhijuQppQUQ nj8MmMp4QcnjE3/t5214l8CuGbz8stU5q0th+6ZnDZCxsoIHCOqRy6Q0D0orYrIoMWRCTnGHVX9r+ z3Ik3zzJSwG73LdgbjioowTWsCtYziacDS4jECYGiVrXg4Bu0073spbBAXio8SnQXs2aqrrp7kyv5 OyXt64Nf2x19tSKVD+2g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tWGff-0000000FpBt-0KK2; Fri, 10 Jan 2025 15:11:35 +0000 Received: from relay9-d.mail.gandi.net ([217.70.183.199]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tWGGr-0000000FgMB-2SjX; Fri, 10 Jan 2025 14:45:58 +0000 Received: by mail.gandi.net (Postfix) with ESMTPSA id F330DFF80E; Fri, 10 Jan 2025 14:45:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1736520355; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=DV0g0pOzPZr7JQwGFl2TLj96VbJ3qNwf0y0PZqiRQeg=; b=Iub4XWBewLpqM4mjtcf282n05DtpSp2+ih1ggGNeYCSDRcaoMk1i7i3N4OYiPgVjR6G+Em TdyUPQQdcrAbzg1kHwRp1fZBvniO8vkZqKZNKLxVoRDmpjP+DYR7LMQNiWGTETMrai+7NR tC2eq5dAERYbVVq2sY5tkBjjk1CLAhSZo+XbiRU5XZNE0NSTkeHVAbL0Vl9yROQ0rUj1M0 OsbKv8+D2Kj7IU1D7PpEFfGH/aBZqRctYRNEieN7ZkJnN4BBx3yN23Zll5WovDvVjwyQXy itpcADRE5oX9JEZfI4AgblOu+Um7po2ZiDqadR4KW3airgn5EftBZOdcv2N/nQ== From: Miquel Raynal Date: Fri, 10 Jan 2025 15:45:22 +0100 Subject: [PATCH v3 20/27] spi: spi-mem: Estimate the time taken by operations MIME-Version: 1.0 Message-Id: <20250110-winbond-6-11-rc1-quad-support-v3-20-7ab4bd56cf6e@bootlin.com> References: <20250110-winbond-6-11-rc1-quad-support-v3-0-7ab4bd56cf6e@bootlin.com> In-Reply-To: <20250110-winbond-6-11-rc1-quad-support-v3-0-7ab4bd56cf6e@bootlin.com> To: Mark Brown , Sanjay R Mehta , Serge Semin , Han Xu , Conor Dooley , Daire McNamara , Matthias Brugger , AngeloGioacchino Del Regno , Haibo Chen , Yogesh Gaur , Heiko Stuebner , Michal Simek , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Jacky Huang , Shan-Chun Hung , Chin-Ting Kuo , =?utf-8?q?C=C3=A9dric_Le_Goa?= =?utf-8?q?ter?= , Joel Stanley , Andrew Jeffery , Avi Fishman , Tomer Maimon , Tali Perry , Patrick Venture , Nancy Yuen , Benjamin Fair , Maxime Coquelin , Alexandre Torgue , Raju Rangoju Cc: Thomas Petazzoni , Steam Lin , linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, imx@lists.linux.dev, linux-riscv@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-rockchip@lists.infradead.org, linux-mtd@lists.infradead.org, linux-aspeed@lists.ozlabs.org, openbmc@lists.ozlabs.org, linux-stm32@st-md-mailman.stormreply.com X-Mailer: b4 0.15-dev X-GND-Sasl: miquel.raynal@bootlin.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250110_064557_893212_AEE31F60 X-CRM114-Status: GOOD ( 15.00 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org In the SPI-NAND layer, we currently make list of operation variants from the fastest one to the slowest and there is a bit of logic in the core to go over them and pick the first one that is supported by the controller, ie. the fastest one among the supported ops. This kind of logic only works if all operations run at the same frequency, but as soon as we introduce per operation max frequencies it is not longer as obvious which operation will be faster, especially since it also depends on the PCB/controller frequency limitation. One way to make this choice more clever is to go over all the variants and for each of them derive an indicator which will help derive the theoretical best. In this case, we derive a theoretical duration for the entire operation and we take the smallest one. Add a helper that parses the spi-mem operation and returns this value. Signed-off-by: Miquel Raynal --- drivers/spi/spi-mem.c | 30 ++++++++++++++++++++++++++++++ include/linux/spi/spi-mem.h | 1 + 2 files changed, 31 insertions(+) diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c index 96374afd0193ca2cf4f50004f66c36dce32894e8..a9f0f47f4759b0e1ce22348e713a3b42cfb8ea9c 100644 --- a/drivers/spi/spi-mem.c +++ b/drivers/spi/spi-mem.c @@ -562,6 +562,36 @@ void spi_mem_adjust_op_freq(struct spi_mem *mem, struct spi_mem_op *op) } EXPORT_SYMBOL_GPL(spi_mem_adjust_op_freq); +/** + * spi_mem_calc_op_duration() - Derives the theoretical length (in ns) of an + * operation. This helps finding the best variant + * among a list of possible choices. + * @op: the operation to benchmark + * + * Some chips have per-op frequency limitations, PCBs usually have their own + * limitations as well, and controllers can support dual, quad or even octal + * modes, sometimes in DTR. All these combinations make it impossible to + * statically list the best combination for all situations. If we want something + * accurate, all these combinations should be rated (eg. with a time estimate) + * and the best pick should be taken based on these calculations. + * + * Returns a ns estimate for the time this op would take. + */ +u64 spi_mem_calc_op_duration(struct spi_mem_op *op) +{ + u64 ncycles = 0; + u32 ns_per_cycles; + + ns_per_cycles = 1000000000 / op->max_freq; + ncycles += ((op->cmd.nbytes * 8) / op->cmd.buswidth) / (op->cmd.dtr ? 2 : 1); + ncycles += ((op->addr.nbytes * 8) / op->addr.buswidth) / (op->addr.dtr ? 2 : 1); + ncycles += ((op->dummy.nbytes * 8) / op->dummy.buswidth) / (op->dummy.dtr ? 2 : 1); + ncycles += ((op->data.nbytes * 8) / op->data.buswidth) / (op->data.dtr ? 2 : 1); + + return ncycles * ns_per_cycles; +} +EXPORT_SYMBOL_GPL(spi_mem_calc_op_duration); + static ssize_t spi_mem_no_dirmap_read(struct spi_mem_dirmap_desc *desc, u64 offs, size_t len, void *buf) { diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h index 306c05dd13789017da2c5339cddc031f03302bb9..c4830dfaff3db5549c45bb7a9c4bf5110fa2e338 100644 --- a/include/linux/spi/spi-mem.h +++ b/include/linux/spi/spi-mem.h @@ -424,6 +424,7 @@ bool spi_mem_default_supports_op(struct spi_mem *mem, int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op); void spi_mem_adjust_op_freq(struct spi_mem *mem, struct spi_mem_op *op); +u64 spi_mem_calc_op_duration(struct spi_mem_op *op); bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op);