From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from polaris.svanheule.net (polaris.svanheule.net [84.16.241.116]) (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 5F5EB311C3B for ; Wed, 29 Oct 2025 08:13:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=84.16.241.116 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761725584; cv=none; b=ONWQV/OnSjFvwVkZ7k43UghgbwHryfqYh5icyVrPrlwh9x3MVhZEA0CSd3SOF6wpqVB4dzOMM7WDYUrYrfbfYKobLNKGp85PhCjTJ9i0kSMG9uWRJk0vjHvD0i7hv9H3M2i5Tw+n5is/fAUibUIMrYIab4Ym+uZYah4xc29+C7Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761725584; c=relaxed/simple; bh=XXRRXFWdZ0VxQByzpM6FNRkKGXzZZbWI//Uo2d8F8UE=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=SlwJzhpAodcXh4tGBuEAJqQCcxsBwrGZEBA/F5Xr3PazWqgZs3Oiz4izEM3ejDL1HeSfNMzB8nq0FmKtgI07ld7tyQZnPkzV6PirMSrPnMHQeo+f8RQioPJP5HyzqfJ37ckfy3E3Scb+QlOFpFuT4WVXqAZVROWKyaXvKD1CRu8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=svanheule.net; spf=pass smtp.mailfrom=svanheule.net; dkim=pass (2048-bit key) header.d=svanheule.net header.i=@svanheule.net header.b=QiF3Cw61; arc=none smtp.client-ip=84.16.241.116 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=svanheule.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=svanheule.net Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=svanheule.net header.i=@svanheule.net header.b="QiF3Cw61" Received: from terra.vega.svanheule.net (2a02-1812-162c-8f00-1e2d-b404-3319-eba8.ip6.access.telenet.be [IPv6:2a02:1812:162c:8f00:1e2d:b404:3319:eba8]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: sander@svanheule.net) by polaris.svanheule.net (Postfix) with ESMTPSA id B87FA690567; Wed, 29 Oct 2025 09:12:54 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=svanheule.net; s=mail1707; t=1761725575; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=TE8ZOOM73wGhypAggpwfjVvh8bO3PXtAh1vc0y4Fz/o=; b=QiF3Cw61U0JHuiYjrNd4wJTzZGnkMaTDEVsrOzOrX5mPi4nX/Zz9ZkkmrSmQSwoXBroULc K+bg0NBauF4d9jW3K90nG+CPwTNyy4nvEBnDZ71bu36AoOo08GBRX6QW0oIbfO7p+ncp/U dateRUsJstymlLexMTM099CP/rRsQeNrTBRhXFoXs5AhyEnAbK9doDczbaOciDYfVMX1Oc /1oCvnz9a+y/34EUSPduX1AKIiMaEjicWCa7ijyBAuOFiDe1x/Hy4v2uU6DWmvreX6LccK Io3AMYj6t9XUmnVn1278uXVPIaIfj2I8qfaYIPVrccDHLWzGkxxXi3foVVMkVg== From: Sander Vanheule To: Mark Brown , linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , "Rafael J . Wysocki" , Danilo Krummrich , Sander Vanheule Subject: [PATCH v6 0/2] regmap: Introduce validity info for flat cache Date: Wed, 29 Oct 2025 09:12:46 +0100 Message-ID: <20251029081248.52607-1-sander@svanheule.net> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The flat cache behaves differently from the other caches, in that it has no way of knowing if a cache entry is valid. Initialization has to happen either by providing defaults, by loading defaults from hardware (via num_reg_defaults_raw), or by performing the required register writes. This difference in behavior may be unexpected to the user [1]. To provide feature parity between the different cache types, a new variant of the flat cache is proposed. This allows user to migrate to the sparse flat cache (or a different cache type) when possible. In order to encourage migration, the second patch adds a new warning to inform the user of their suspicious cache. [1] https://lore.kernel.org/linux-gpio/e461ca08-ad28-44fe-85f1-afe332c1d43d@topic.nl/ --- Changes since v5: Link: https://lore.kernel.org/lkml/20251023135032.229511-1-sander@svanheule.net/ - zero-initialize cache for compatibiliy - Update regcache_type comment to document the difference between the flat caches Changes since v4: Link: https://lore.kernel.org/lkml/20251022200408.63027-1-sander@svanheule.net/ - Improve formatting of log message - Reduce logging to not confuse KUnit test result parser - Add sparse flat cache to all KUnit config lists Changes since v3: Link: https://lore.kernel.org/lkml/20250109180256.6269-1-sander@svanheule.net/ - Split changes into two patches to provide a migration path Changes since v2: Link: https://lore.kernel.org/all/20250109151106.38645-1-sander@svanheule.net/ - Complete renaming of index variables so regcache-flat.c compiles again Changes since v1: Link: https://lore.kernel.org/all/20241231100256.194753-1-sander@svanheule.net/ - Fix off-by-one in length for bitmap_clear() - Add REGCACHE_FLAT to the list of sparse cache tests Sander Vanheule (2): regmap: add flat cache with sparse validity regmap: warn users about uninitialized flat cache drivers/base/regmap/internal.h | 1 + drivers/base/regmap/regcache-flat.c | 96 +++++++++++++++++++++++++---- drivers/base/regmap/regcache.c | 1 + drivers/base/regmap/regmap-kunit.c | 22 +++++++ include/linux/regmap.h | 17 +++-- 5 files changed, 120 insertions(+), 17 deletions(-) -- 2.51.0