From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3A485375AC4; Tue, 6 Oct 2026 07:03:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791270200; cv=none; b=tnk7PzpsbmOv8+akyzyBFrKDkwH/7Gi0zq8l1JmZ9n+4wqiEAaXFOEBWm4cqgBlcBJhs3Qm7EStMsdbLNwH34mjPX+4ses6bB0W1xTEGA+eox3oY8SUeacJtElfCBCc5yFrtmekw0ru7V2ihHp96SR0MXHsv5Ymn0k8OeDwYHYo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791270200; c=relaxed/simple; bh=JibEKNEcmqb57qhexlohigAcFZyJJ9PXqg76F+GByhM=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=Cl0l47TbxEOyiSkCHhSSbpi/hRivepbYWJDj193RgojTYSE0xbmopYiE+x8eQUJn/tjzDN7kD85dy4AaX20bm8I7+HI1/27cdDq7OlgVNWNHNm6OhUOjrGlh7gUcbN0aNVtpLXoAPd0ZBAiZmSQpM/iwM/NDQ6s987mWuH+LEwI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=dC+4del+; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="dC+4del+" Received: by smtp.kernel.org (Postfix) with ESMTPS id 0FD37C4AF13; Tue, 6 Oct 2026 07:03:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1791270199; bh=JibEKNEcmqb57qhexlohigAcFZyJJ9PXqg76F+GByhM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=dC+4del+bSd22JNDwtGhVHPQ0pXwhcRaRJGlGO+oLVuW3ByDlMm05j/WMTnJBbOiD 2F26JFh5HWOZVkhCLMHNSRQoxnvnFMi+i6DTOfVytM2k0v2s2sUNand4dRmtKzhneh dHsw1tsKjq9abykTppCQ+YSNNvSwTG6n7fu9noxfUc7zeUzVjuBDXRG9jSv7pfyLPF Wz7BxDarLcjBQbgYcBGK7WcAQdc+EjllZ8MBsSvC/ymlanQ0z0oEHOT//OzDTscs2f L7LIlC9vIoEa+i9pd+3RYdI42xipO+IHPpM+67Fg+DzQNlCMNbjf8hAobtu9+NVC59 nvvWtRZlqSpFQ== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3CA4CA5FFC; Tue, 6 Oct 2026 07:03:18 +0000 (UTC) From: Michael Reeves via B4 Relay Date: Tue, 06 Oct 2026 18:03:16 +1100 Subject: [PATCH v3 2/2] regmap: Drop map lock during cache init and exit Precedence: bulk X-Mailing-List: linux-kernel@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: <20261006-regcache-lifecycle-submit-v3-2-37bdd82fd47c@gmail.com> References: <20261006-regcache-lifecycle-submit-v3-0-37bdd82fd47c@gmail.com> In-Reply-To: <20261006-regcache-lifecycle-submit-v3-0-37bdd82fd47c@gmail.com> To: Mark Brown , Alice Ryhl , Andrew Ballance Cc: Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , "Liam R. Howlett" , linux-kernel@vger.kernel.org, driver-core@lists.linux.dev, maple-tree@lists.infradead.org, asahi@lists.linux.dev, linux-mm@kvack.org, Michael Reeves X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1791270197; l=4482; i=michael.reeves077@gmail.com; s=fedora-20260918; h=from:subject:message-id; bh=SZnYqaht9eHldUBPSRohyllzfPag5yZhmg8EqkFgLTI=; b=uN5nLx6ZAujPvKZMbgpw3DySy1o1+pySMXk2i51JpxFsW1vI7ul6yjeaShfQMDox58eZ0ur+P QigVOzCdaz4BIRbCRE2hVKGYtz7KbVfe1XF33e16jGnFVgEnrsdLO0B X-Developer-Key: i=michael.reeves077@gmail.com; a=ed25519; pk=VJ0TvyQ9TvfzYZa908YSE9kpkjFLLD5luv0bERu+boc= X-Endpoint-Received: by B4 Relay for michael.reeves077@gmail.com/fedora-20260918 with auth_id=1035 X-Original-From: Michael Reeves Reply-To: michael.reeves077@gmail.com From: Michael Reeves On systems with CONFIG_PROVE_RAW_LOCK_NESTING enabled, Apple GPIO probe triggers an "Invalid wait context" lockdep warning. The driver uses a regmap with a raw spinlock and REGCACHE_FLAT. During regcache_init(), regcache_flat_init() allocates memory while holding the raw spinlock. The memory allocator can acquire a non-raw spinlock, which causes an invalid raw-to-non-raw lock nesting error. The abbreviated call chain is: apple_gpio_pinctrl_probe regcache_init regcache_flat_init __kmalloc_noprof __pcs_replace_empty_main refill_objects _raw_spin_lock_irqsave Cache allocation occurs before the regmap is published, cache destruction occurs after users have stopped accessing it, and regmap_reinit_cache() requires callers to prevent concurrent access. Remove the outer map lock from cache initialization and destruction. Keep it for cache population and normal register access. The Maple cache still uses its internal spinlock during teardown. That lock can also be acquired from hard IRQ context during register access. Add Maple-state irqsave helpers and use them during teardown to preserve the lock's IRQ-safe lockdep state. Fixes: fd4ebc07b4df ("regmap: Hold the regmap lock when allocating and freeing the cache") Suggested-by: Mark Brown Suggested-by: Liam R. Howlett Signed-off-by: Michael Reeves --- drivers/base/regmap/regcache-maple.c | 9 +++++++-- drivers/base/regmap/regcache.c | 6 ------ include/linux/maple_tree.h | 4 ++++ 3 files changed, 11 insertions(+), 8 deletions(-) diff --git a/drivers/base/regmap/regcache-maple.c b/drivers/base/regmap/regcache-maple.c index e46fe5c32b..16e488da5f 100644 --- a/drivers/base/regmap/regcache-maple.c +++ b/drivers/base/regmap/regcache-maple.c @@ -312,16 +312,21 @@ static void regcache_maple_exit(struct regmap *map) struct maple_tree *mt = map->cache; MA_STATE(mas, mt, 0, UINT_MAX); unsigned int *entry; + unsigned long flags; /* if we've already been called then just return */ if (!mt) return; - mas_lock(&mas); + /* + * Register access may take the Maple lock from hard IRQ context, so + * preserve its IRQ-safe lockdep state during teardown. + */ + mas_lock_irqsave(&mas, flags); mas_for_each(&mas, entry, UINT_MAX) kfree(entry); __mt_destroy(mt); - mas_unlock(&mas); + mas_unlock_irqrestore(&mas, flags); kfree(mt); map->cache = NULL; diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c index 0d58d900a2..b137ded7fd 100644 --- a/drivers/base/regmap/regcache.c +++ b/drivers/base/regmap/regcache.c @@ -225,9 +225,7 @@ int regcache_init(struct regmap *map, const struct regmap_config *config) if (map->cache_ops->init) { dev_dbg(map->dev, "Initializing %s cache\n", map->cache_ops->name); - map->lock(map->lock_arg); ret = map->cache_ops->init(map); - map->unlock(map->lock_arg); if (ret) goto err_free_reg_defaults; } @@ -259,9 +257,7 @@ int regcache_init(struct regmap *map, const struct regmap_config *config) err_exit: if (map->cache_ops->exit) { dev_dbg(map->dev, "Destroying %s cache\n", map->cache_ops->name); - map->lock(map->lock_arg); map->cache_ops->exit(map); - map->unlock(map->lock_arg); } err_free_reg_defaults: kfree(map->reg_defaults); @@ -281,9 +277,7 @@ void regcache_exit(struct regmap *map) if (map->cache_ops->exit) { dev_dbg(map->dev, "Destroying %s cache\n", map->cache_ops->name); - map->lock(map->lock_arg); map->cache_ops->exit(map); - map->unlock(map->lock_arg); } kfree(map->reg_defaults); diff --git a/include/linux/maple_tree.h b/include/linux/maple_tree.h index e595ae5cd0..f6491a92ea 100644 --- a/include/linux/maple_tree.h +++ b/include/linux/maple_tree.h @@ -507,9 +507,13 @@ struct ma_wr_state { }; #define mas_lock(mas) spin_lock(&((mas)->tree->ma_lock)) +#define mas_lock_irqsave(mas, flags) \ + spin_lock_irqsave(&((mas)->tree->ma_lock), flags) #define mas_lock_nested(mas, subclass) \ spin_lock_nested(&((mas)->tree->ma_lock), subclass) #define mas_unlock(mas) spin_unlock(&((mas)->tree->ma_lock)) +#define mas_unlock_irqrestore(mas, flags) \ + spin_unlock_irqrestore(&((mas)->tree->ma_lock), flags) /* * Special values for ma_state.node. -- 2.55.0