From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 745EA4A2E07 for ; Wed, 1 Jul 2026 16:00:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=205.220.168.131 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782921657; cv=none; b=fIbjG2wdERRFNOMBcZ7PRoxXCaanshGr7dHc008QwYzZGXh6HBfJqqs3cyCTHbsr1FD88W3WksZ3ZrKzxRhRUbrFNTgvDAEvpdvd64eVW+JY8u/10usqNFkT+UophzhRwUhqxObzTeEtZjsJzNDP6YATzxk1rC7zQTOpCYai/zg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782921657; c=relaxed/simple; bh=sL87l+fR0fxeRESx/GCRKGWxg1ci/hNuvJqQzq58rT4=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=kIJG1b7dMlp4zVenoUu9SEcJj1/f/8gF2slF2d5FPrNPoO6n9zxbt8a0mwZe4bNlGeITUx5LGp33HevCga4YJj0czaDyhR3QdKng+iDRgfIPZJk665iw42lSBnKX5fCdfNFg6b4vjKxK1bSW05A/57RfPhotrRqn1RrxtkZk5R8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b=omlpQsSr; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b=bPS0GAyX; arc=none smtp.client-ip=205.220.168.131 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.b="omlpQsSr"; dkim=pass (2048-bit key) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.b="bPS0GAyX" Received: from pps.filterd (m0279866.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 661FoCu51470179 for ; Wed, 1 Jul 2026 16:00:48 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= ruF9ANzInv8cVmA5nRWoHkeo1OOBUskTgPEB+I0ZmEc=; b=omlpQsSr1sOyXZ+r KQ0kNoc7sLp5coqaxzsAE06W/YYe1Dyja3tUHpMfFosx25/rgMdpfKrckoSSSV7E hZyvCCkKGn+cPoRC+Vs6Xd6CqQ7+QnO7JirFDkCPxbtFnkNJ/gnW9lSbDdpzeCGc rs9TX1O6gL3ZAtzPoN8LgFPUMEHdQOwZnwwbCaxW3aDrhEWP3nPTmSw/seMiB+dR aS2d7YfFiNpL8z9jf3wlW2L3yDYvkm8PYyZuvz/c07XhWyMYnY4I446LtR008FwM TUN+Kpmhc2V0QyHwKOOdWaBmRNStyQQi3ZPwi0k1yo6HIEAcrhcon67WSC61+JSn Ed1blg== Received: from mail-ua1-f70.google.com (mail-ua1-f70.google.com [209.85.222.70]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4f4jtqn3kr-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Wed, 01 Jul 2026 16:00:47 +0000 (GMT) Received: by mail-ua1-f70.google.com with SMTP id a1e0cc1a2514c-963b099b539so1788694241.0 for ; Wed, 01 Jul 2026 09:00:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1782921647; x=1783526447; darn=vger.kernel.org; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:from:to:cc:subject:date:message-id :reply-to; bh=ruF9ANzInv8cVmA5nRWoHkeo1OOBUskTgPEB+I0ZmEc=; b=bPS0GAyXdihfYx0A+iHkxQGNYfWxpwjeubWmfR1EXsVGcFQa1BLNpQe/b9ErenwECI jBJeuREEiT0juX6Nc1JbKTSRz63amtVloZVKU9qBpKXx5fol1F+iesw7NA4/X4ZZG15W qtE7sRytn6sdIZjd0gnjQhJTcjne64xq3o1uKWZfs8+pmwKkrJV15UTNkqrvv5nZn1CI CzhzWwoDDgCrhwQcaFgpDHPdmUNHA71RlkCvRMgAPkgeafvOxWJ3NULrCwJzhGuvm4zN Gcy8rMqHKVUT4hZyoZapJPdahsts/6ZGsBnvUBpNk8G3bIBNRVwfxzVaEpa1H9wfy+XZ 45aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782921647; x=1783526447; h=cc:to:in-reply-to:references:message-id:content-transfer-encoding :mime-version:subject:date:from:x-gm-gg:x-gm-message-state:from:to :cc:subject:date:message-id:reply-to; bh=ruF9ANzInv8cVmA5nRWoHkeo1OOBUskTgPEB+I0ZmEc=; b=DmzIcs1CtQHaMfDP8dpWvkDQAZ7PKR/lfIDmiqUZ4TulRERtUrVrt+CN4rcP201vE5 b7QFb069o6asRyM2Y3I/xU/Om8a3c5RrylssbjYpLNks5h8hI/3r2MZjiqf46iiYBVYP 3qYlaZKMJ3cCAan/fCs51xd8UlTnViP+12gztzT3un0IikT2kLR5XESDPmh4DP0SZAON ciXb7CC+ppIFQVhtnIWjOOYADfRVRbMs5G4byskwYoBtvwLQ5XCI8Y7YLjmrwFEl/SCX /S3bchb6sFAO83FxJ/yrggnrPextqE392l8dttHGt8AbEd6vFtJN+c+4GHE+oYxWhW/H 23Dw== X-Forwarded-Encrypted: i=1; AHgh+RreSg3+QpeVBxSLay+IAmyPeOt3Kjrv3coZwDhEuHVph4g5H0zkIHNwgCmWrE6WfSUsIqr24Cg=@vger.kernel.org X-Gm-Message-State: AOJu0YzaKDVEDlX+dijaFZ2mmQN+U0L6kt770aG0M7jWjdTyPVQLPElB 1dFN+cjGvq/hMrMlj0mMagYIlfqm8gXRCR2oA1u5QOJxKHZ+EtnZC+Gp850Fq/CsXAiPtl7zpPM PjPxUH5m9DBLyw2tOrJGQ5w4HRYIzpdhOguQFXPodKcu84J5V+a5s0Z4ftj0= X-Gm-Gg: AfdE7cmRI2clGIYL6zeDpmbIoQcyc8jhpvH01fNm4PlQKxpUJcZ5hpQk752BReYRDpn 2Yob+MyeFqrt21zxTNJbpLpn7dzPCDexRB10ppL3K0uLAr/evgSwc7Xf6Xw5QvGLgKEYtfEL7Fs CQ2DjFklKldMDqERLJ8qavcxrtR4G1Hxs5YfO+07ydGvOP3cu6VF0kptCe9JXhh2i/VwHkKoa78 qY43Wp4k6ga+lPWpw2i6NXnZbs2JDtdSOELhTuqGDtXAiM75k3mn7hFfHYcHbwei07sP0gTlvC3 nHsv6pggRtHOMxvsLoLTMVW3oGuaS+0j49AF193V0C6kiivmcd5Z1lcrLPbX3Bo/FD5gAfwiyjJ YApAs0tv3jeweCi5BxVAiDZV/Z35LSFh7l3QVCoijUydwNjAYPTKtplTJrJ3DalZrol+3efF/7T +k6d6zcmcb5LkWYqQYHAiLoorhWHusSZOENgQV0vAA+8AQecvUcVr4JcU8nDqCgHA= X-Received: by 2002:a05:6102:1804:b0:735:d53f:259e with SMTP id ada2fe7eead31-73bd2842dd8mr1872885137.5.1782921646524; Wed, 01 Jul 2026 09:00:46 -0700 (PDT) X-Received: by 2002:a05:6102:1804:b0:735:d53f:259e with SMTP id ada2fe7eead31-73bd2842dd8mr1872784137.5.1782921645053; Wed, 01 Jul 2026 09:00:45 -0700 (PDT) Received: from QCOM-eG0v1AUPpu.na.qualcomm.com ([2a01:e0a:830:450:809d:5d56:19d9:ff8b]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-c1288d19e03sm296613066b.4.2026.07.01.09.00.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 01 Jul 2026 09:00:44 -0700 (PDT) From: Loic Poulain Date: Wed, 01 Jul 2026 18:00:29 +0200 Subject: [PATCH v7 5/9] block: implement NVMEM provider Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260701-block-as-nvmem-v7-5-3fe8205ef0a8@oss.qualcomm.com> References: <20260701-block-as-nvmem-v7-0-3fe8205ef0a8@oss.qualcomm.com> In-Reply-To: <20260701-block-as-nvmem-v7-0-3fe8205ef0a8@oss.qualcomm.com> To: Ulf Hansson , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Bjorn Andersson , Konrad Dybcio , Jens Axboe , Johannes Berg , Jeff Johnson , Bartosz Golaszewski , Marcel Holtmann , Luiz Augusto von Dentz , Balakrishna Godavarthi , Rocky Liao , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Srinivas Kandagatla , Andrew Lunn , Heiner Kallweit , Russell King , Saravana Kannan , Christian Marangi Cc: linux-mmc@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-block@vger.kernel.org, linux-wireless@vger.kernel.org, ath10k@lists.infradead.org, linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org, daniel@makrotopia.org, Loic Poulain , Bartosz Golaszewski X-Mailer: b4 0.14.2 X-Proofpoint-ORIG-GUID: XAp1JHUIwA0KZVkgdX21L_O526ffkQNZ X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNzAxMDE2OSBTYWx0ZWRfXxmSrc0PPlmjA 0V1aHkm/1t29bcKeWvlfSLrK1KmCgOzA8sz9gQAXaS+ATqT2er8Kmq0cvvsYo5itWHXV3jHxePZ 7lbM9fv7uyg/T5HdklRhTYvnotj3k5IK/ofLpGTVjCPU5JeZqzQv6hsqQEclRlgDt4QkP1CNdiz 0P7L57FmFNhaWnSNiQXEFo361GJdioweaS11kpyOUMRg8Be3fJDQGDA3hI5YB7YAKYZmq8YkYE6 jeLvMUyRNKgMPZhdZ6JUMwdPEf9IH/MTIUiuc1Fn/ErefXFwoXOqImcMEIcBmiBFBaRfJ5doqY5 5cDMbPUA/1ePuaQWqkAMJw3mvVQEdMZfU0OnrndDbHsX8k5Hz/GFjQdFrsV/KBOyyXoSR0lDR3c iDY2ugI0L6eqLeDSfL+rHIL9YTTmRIeWQdtP6PMf3tuO96V8Rt8f6weezLzXSaWE8NdNMHLphk+ scl4wOpnEQRCeyb2MNg== X-Proofpoint-GUID: XAp1JHUIwA0KZVkgdX21L_O526ffkQNZ X-Authority-Analysis: v=2.4 cv=LIZWhpW9 c=1 sm=1 tr=0 ts=6a4539af cx=c_pps a=R6oCqFB+Yf/t2GF8e0/dFg==:117 a=xqWC_Br6kY4A:10 a=IkcTkHD0fZMA:10 a=RAioF0-LDSMA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=YMgV9FUhrdKAYTUUvYB2:22 a=VT4XjZGOAAAA:8 a=EUspDBNiAAAA:8 a=QS6QONgytJYYblx7mpIA:9 a=QEXdDO2ut3YA:10 a=TD8TdBvy0hsOASGTdmB-:22 a=6CpsfURP9XNmmWg3j1mJ:22 X-Proofpoint-Spam-Info: AW1haW4tMjYwNzAxMDE2OSBTYWx0ZWRfX1DFVy11eWkjH NL/gqqIXzS/V6wfYVoJNmV0EWcmAT8LRE0l9Rrkh+XePFWAv+B9GwCkoE4606W5+n4NUae3Btzx 1MWeneeWfLF1t56wqakRHXtr85tl4QU= X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.125,FMLib:17.12.100.49 definitions=2026-07-01_03,2026-06-26_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 priorityscore=1501 phishscore=0 lowpriorityscore=0 clxscore=1015 malwarescore=0 bulkscore=0 adultscore=0 impostorscore=0 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2607010169 From: Daniel Golle On embedded devices using an eMMC it is common that one or more partitions on the eMMC are used to store MAC addresses and Wi-Fi calibration EEPROM data. Allow referencing the partition in device tree for the kernel and Wi-Fi drivers accessing it via the NVMEM layer. NVMEM is registered for a block device whose OF node describes an NVMEM layout, either via an "nvmem-layout" child or by being a "fixed-layout" node itself (e.g. an eMMC boot partition associated through its mmc-card node). Signed-off-by: Daniel Golle Co-developed-by: Loic Poulain Signed-off-by: Loic Poulain Reviewed-by: Bartosz Golaszewski --- block/Kconfig | 9 ++++ block/Makefile | 1 + block/blk-nvmem.c | 109 ++++++++++++++++++++++++++++++++++++++++++++++ block/blk.h | 8 ++++ block/genhd.c | 4 ++ include/linux/blk_types.h | 4 ++ 6 files changed, 135 insertions(+) diff --git a/block/Kconfig b/block/Kconfig index 15027963472d7b40e27b9097a5993c457b5b3054..0b33747e16dc33473683706f75c92bdf8b648f7c 100644 --- a/block/Kconfig +++ b/block/Kconfig @@ -209,6 +209,15 @@ config BLK_INLINE_ENCRYPTION_FALLBACK by falling back to the kernel crypto API when inline encryption hardware is not present. +config BLK_NVMEM + bool "Block device NVMEM provider" + depends on OF + depends on NVMEM + help + Allow block devices (or partitions) to act as NVMEM providers, + typically used with eMMC to store MAC addresses or Wi-Fi + calibration data on embedded devices. + source "block/partitions/Kconfig" config BLK_PM diff --git a/block/Makefile b/block/Makefile index 7dce2e44276c4274c11a0a61121c83d9c43d6e0c..d7ac389e71902bc091a8800ea266190a43b3e63d 100644 --- a/block/Makefile +++ b/block/Makefile @@ -36,3 +36,4 @@ obj-$(CONFIG_BLK_INLINE_ENCRYPTION) += blk-crypto.o blk-crypto-profile.o \ blk-crypto-sysfs.o obj-$(CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK) += blk-crypto-fallback.o obj-$(CONFIG_BLOCK_HOLDER_DEPRECATED) += holder.o +obj-$(CONFIG_BLK_NVMEM) += blk-nvmem.o diff --git a/block/blk-nvmem.c b/block/blk-nvmem.c new file mode 100644 index 0000000000000000000000000000000000000000..49e9b5d4410d5e935c4ad9674c6909453fe027ff --- /dev/null +++ b/block/blk-nvmem.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * block device NVMEM provider + * + * Copyright (c) 2024 Daniel Golle + * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries. + * + * Useful on devices using a partition on an eMMC for MAC addresses or + * Wi-Fi calibration EEPROM data. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#include "blk.h" + +static int blk_nvmem_reg_read(void *priv, unsigned int from, void *val, size_t bytes) +{ + dev_t devt = (dev_t)(uintptr_t)priv; + size_t bytes_left = bytes; + loff_t pos = from; + int ret = 0; + + struct file *bdev_file __free(fput) = + bdev_file_open_by_dev(devt, BLK_OPEN_READ, NULL, NULL); + if (IS_ERR(bdev_file)) + return PTR_ERR(bdev_file); + + while (bytes_left) { + pgoff_t f_index = pos >> PAGE_SHIFT; + struct folio *folio; + size_t folio_off; + size_t to_read; + + folio = read_mapping_folio(bdev_file->f_mapping, f_index, NULL); + if (IS_ERR(folio)) { + ret = PTR_ERR(folio); + break; + } + + folio_off = offset_in_folio(folio, pos); + to_read = min(bytes_left, folio_size(folio) - folio_off); + memcpy_from_folio(val, folio, folio_off, to_read); + pos += to_read; + bytes_left -= to_read; + val += to_read; + folio_put(folio); + } + + return ret; +} + +int blk_nvmem_add(struct block_device *bdev) +{ + struct device *dev = &bdev->bd_device; + struct nvmem_config config = {}; + + /* skip devices which do not have a device tree node */ + if (!dev_of_node(dev)) + return 0; + + /* skip devices without an nvmem layout defined */ + struct device_node *child __free(device_node) = + of_get_child_by_name(dev_of_node(dev), "nvmem-layout"); + if (!child && !of_device_is_compatible(dev_of_node(dev), "fixed-layout")) + return 0; + + /* + * skip block device too large to be represented as NVMEM devices, + * nvmem_config.size is a signed int + */ + if (bdev_nr_bytes(bdev) > INT_MAX) { + dev_warn(dev, "block device too large to be an NVMEM provider\n"); + return 0; + } + + config.id = NVMEM_DEVID_NONE; + config.dev = dev; + config.name = dev_name(dev); + config.owner = THIS_MODULE; + config.priv = (void *)(uintptr_t)dev->devt; + config.reg_read = blk_nvmem_reg_read; + config.size = bdev_nr_bytes(bdev); + config.word_size = 1; + config.stride = 1; + config.read_only = true; + config.root_only = true; + config.ignore_wp = true; + config.of_node = to_of_node(dev->fwnode); + + bdev->bd_nvmem = nvmem_register(&config); + if (IS_ERR(bdev->bd_nvmem)) + return dev_err_probe(dev, PTR_ERR(bdev->bd_nvmem), + "Failed to register NVMEM device\n"); + + return 0; +} + +void blk_nvmem_del(struct block_device *bdev) +{ + nvmem_unregister(bdev->bd_nvmem); + bdev->bd_nvmem = NULL; +} diff --git a/block/blk.h b/block/blk.h index ec4674cdf2ead4fd259ff5fc42401f591e684ee9..ed0c10168ba7be10855509637f824a9cea2b9ccb 100644 --- a/block/blk.h +++ b/block/blk.h @@ -757,4 +757,12 @@ static inline void blk_debugfs_unlock(struct request_queue *q, memalloc_noio_restore(memflags); } +#ifdef CONFIG_BLK_NVMEM +int blk_nvmem_add(struct block_device *bdev); +void blk_nvmem_del(struct block_device *bdev); +#else +static inline int blk_nvmem_add(struct block_device *bdev) { return 0; } +static inline void blk_nvmem_del(struct block_device *bdev) {} +#endif + #endif /* BLK_INTERNAL_H */ diff --git a/block/genhd.c b/block/genhd.c index 7d6854fd28e95ae9134309679a7c6a937f5b7db8..1b2382de6fb30c1e5f60f45c04dc03ed3bf5d5f2 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -421,6 +421,8 @@ static void add_disk_final(struct gendisk *disk) */ dev_set_uevent_suppress(ddev, 0); disk_uevent(disk, KOBJ_ADD); + + blk_nvmem_add(disk->part0); } blk_apply_bdi_limits(disk->bdi, &disk->queue->limits); @@ -704,6 +706,8 @@ static void __del_gendisk(struct gendisk *disk) disk_del_events(disk); + blk_nvmem_del(disk->part0); + /* * Prevent new openers by unlinked the bdev inode. */ diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 8808ee76e73c09e0ceaac41ba59e86fb0c4efc64..6ed173c649025b95cce9253b27f68f2c7dbab8eb 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -15,6 +15,7 @@ struct bio_set; struct bio; struct bio_integrity_payload; +struct nvmem_device; struct page; struct io_context; struct cgroup_subsys_state; @@ -73,6 +74,9 @@ struct block_device { int bd_writers; #ifdef CONFIG_SECURITY void *bd_security; +#endif +#ifdef CONFIG_BLK_NVMEM + struct nvmem_device *bd_nvmem; #endif /* * keep this out-of-line as it's both big and not needed in the fast -- 2.34.1