From patchwork Fri Oct 8 16:22:23 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 12545707 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B2DD2C433EF for ; Fri, 8 Oct 2021 16:22:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F90861042 for ; Fri, 8 Oct 2021 16:22:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232659AbhJHQYm (ORCPT ); Fri, 8 Oct 2021 12:24:42 -0400 Received: from relay10.mail.gandi.net ([217.70.178.230]:60925 "EHLO relay10.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232682AbhJHQYl (ORCPT ); Fri, 8 Oct 2021 12:24:41 -0400 Received: (Authenticated sender: miquel.raynal@bootlin.com) by relay10.mail.gandi.net (Postfix) with ESMTPSA id DF421240012; Fri, 8 Oct 2021 16:22:41 +0000 (UTC) From: Miquel Raynal To: Richard Weinberger , Vignesh Raghavendra , Tudor Ambarus , Cc: Rob Herring , Mark Brown , Xiangsheng Hou , Boris Brezillon , devicetree@vger.kernel.org, linux-spi@vger.kernel.org, linux-kernel@vger.kernel.org, jaimeliao@mxic.com.tw, juliensu@mxic.com.tw, Thomas Petazzoni , Miquel Raynal Subject: [RFC PATCH 05/10] mtd: nand: ecc: Add infrastructure to support hardware engines Date: Fri, 8 Oct 2021 18:22:23 +0200 Message-Id: <20211008162228.1753083-6-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20211008162228.1753083-1-miquel.raynal@bootlin.com> References: <20211008162228.1753083-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org Add the necessary helpers to register/unregister hardware ECC engines that will be called from ECC engine drivers. Also add helpers to get the right engine from the user perspective. Keep a reference of the in use ECC engine in order to prevent modules to be unloaded. Put the reference when the engine gets retired. A static list of hardware (only) ECC engines is setup to keep track of the registered engines. Signed-off-by: Miquel Raynal --- drivers/mtd/nand/core.c | 10 +++-- drivers/mtd/nand/ecc.c | 89 ++++++++++++++++++++++++++++++++++++++++ include/linux/mtd/nand.h | 11 +++++ 3 files changed, 107 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/nand/core.c b/drivers/mtd/nand/core.c index df9646685c91..5628bd410f7e 100644 --- a/drivers/mtd/nand/core.c +++ b/drivers/mtd/nand/core.c @@ -232,7 +232,9 @@ static int nanddev_get_ecc_engine(struct nand_device *nand) nand->ecc.engine = nand_ecc_get_on_die_hw_engine(nand); break; case NAND_ECC_ENGINE_TYPE_ON_HOST: - pr_err("On-host hardware ECC engines not supported yet\n"); + nand->ecc.engine = nand_ecc_get_on_host_hw_engine(nand); + if (PTR_ERR(nand->ecc.engine) == -EPROBE_DEFER) + return -EPROBE_DEFER; break; default: pr_err("Missing ECC engine type\n"); @@ -252,7 +254,7 @@ static int nanddev_put_ecc_engine(struct nand_device *nand) { switch (nand->ecc.ctx.conf.engine_type) { case NAND_ECC_ENGINE_TYPE_ON_HOST: - pr_err("On-host hardware ECC engines not supported yet\n"); + nand_ecc_put_on_host_hw_engine(nand); break; case NAND_ECC_ENGINE_TYPE_NONE: case NAND_ECC_ENGINE_TYPE_SOFT: @@ -297,7 +299,9 @@ int nanddev_ecc_engine_init(struct nand_device *nand) /* Look for the ECC engine to use */ ret = nanddev_get_ecc_engine(nand); if (ret) { - pr_err("No ECC engine found\n"); + if (ret != -EPROBE_DEFER) + pr_err("No ECC engine found\n"); + return ret; } diff --git a/drivers/mtd/nand/ecc.c b/drivers/mtd/nand/ecc.c index 6c43dfda01d4..3aa56c990d11 100644 --- a/drivers/mtd/nand/ecc.c +++ b/drivers/mtd/nand/ecc.c @@ -96,6 +96,12 @@ #include #include #include +#include +#include +#include + +static LIST_HEAD(on_host_hw_engines); +static DEFINE_MUTEX(on_host_hw_engines_mutex); /** * nand_ecc_init_ctx - Init the ECC engine context @@ -611,6 +617,89 @@ struct nand_ecc_engine *nand_ecc_get_on_die_hw_engine(struct nand_device *nand) } EXPORT_SYMBOL(nand_ecc_get_on_die_hw_engine); +int nand_ecc_register_on_host_hw_engine(struct nand_ecc_engine *engine) +{ + struct nand_ecc_engine *item; + + if (!engine) + return -ENOTSUPP; + + /* Prevent multiple registrations of one engine */ + list_for_each_entry(item, &on_host_hw_engines, node) + if (item == engine) + return 0; + + mutex_lock(&on_host_hw_engines_mutex); + list_add_tail(&engine->node, &on_host_hw_engines); + mutex_unlock(&on_host_hw_engines_mutex); + + return 0; +} +EXPORT_SYMBOL(nand_ecc_register_on_host_hw_engine); + +int nand_ecc_unregister_on_host_hw_engine(struct nand_ecc_engine *engine) +{ + if (!engine) + return -ENOTSUPP; + + mutex_lock(&on_host_hw_engines_mutex); + list_del(&engine->node); + mutex_unlock(&on_host_hw_engines_mutex); + + return 0; +} +EXPORT_SYMBOL(nand_ecc_unregister_on_host_hw_engine); + +struct nand_ecc_engine *nand_ecc_match_on_host_hw_engine(struct device *dev) +{ + struct nand_ecc_engine *item; + + list_for_each_entry(item, &on_host_hw_engines, node) + if (item->dev == dev) + return item; + + return NULL; +} +EXPORT_SYMBOL(nand_ecc_match_on_host_hw_engine); + +struct nand_ecc_engine *nand_ecc_get_on_host_hw_engine(struct nand_device *nand) +{ + struct nand_ecc_engine *engine = NULL; + struct device *dev = &nand->mtd.dev; + struct platform_device *pdev; + struct device_node *np; + + if (list_empty(&on_host_hw_engines)) + return NULL; + + /* Check for an explicit nand-ecc-engine property */ + np = of_parse_phandle(dev->of_node, "nand-ecc-engine", 0); + if (np) { + pdev = of_find_device_by_node(np); + if (!pdev) + return ERR_PTR(-EPROBE_DEFER); + + engine = nand_ecc_match_on_host_hw_engine(&pdev->dev); + platform_device_put(pdev); + of_node_put(np); + + if (!engine) + return ERR_PTR(-EPROBE_DEFER); + } + + if (engine) + get_device(engine->dev); + + return engine; +} +EXPORT_SYMBOL(nand_ecc_get_on_host_hw_engine); + +void nand_ecc_put_on_host_hw_engine(struct nand_device *nand) +{ + put_device(nand->ecc.engine->dev); +} +EXPORT_SYMBOL(nand_ecc_put_on_host_hw_engine); + MODULE_LICENSE("GPL"); MODULE_AUTHOR("Miquel Raynal "); MODULE_DESCRIPTION("Generic ECC engine"); diff --git a/include/linux/mtd/nand.h b/include/linux/mtd/nand.h index 32fc7edf65b3..5ffd3e359515 100644 --- a/include/linux/mtd/nand.h +++ b/include/linux/mtd/nand.h @@ -265,10 +265,16 @@ struct nand_ecc_engine_ops { /** * struct nand_ecc_engine - ECC engine abstraction for NAND devices + * @dev: Host device + * @node: Private field for registration time * @ops: ECC engine operations + * @priv: Private data */ struct nand_ecc_engine { + struct device *dev; + struct list_head node; struct nand_ecc_engine_ops *ops; + void *priv; }; void of_get_nand_ecc_user_config(struct nand_device *nand); @@ -279,8 +285,13 @@ int nand_ecc_prepare_io_req(struct nand_device *nand, int nand_ecc_finish_io_req(struct nand_device *nand, struct nand_page_io_req *req); bool nand_ecc_is_strong_enough(struct nand_device *nand); +int nand_ecc_register_on_host_hw_engine(struct nand_ecc_engine *engine); +int nand_ecc_unregister_on_host_hw_engine(struct nand_ecc_engine *engine); struct nand_ecc_engine *nand_ecc_get_sw_engine(struct nand_device *nand); struct nand_ecc_engine *nand_ecc_get_on_die_hw_engine(struct nand_device *nand); +struct nand_ecc_engine *nand_ecc_get_on_host_hw_engine(struct nand_device *nand); +struct nand_ecc_engine *nand_ecc_match_on_host_hw_engine(struct device *dev); +void nand_ecc_put_on_host_hw_engine(struct nand_device *nand); #if IS_ENABLED(CONFIG_MTD_NAND_ECC_SW_HAMMING) struct nand_ecc_engine *nand_ecc_sw_hamming_get_engine(void);