From patchwork Thu Feb 15 14:46:31 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathieu Desnoyers X-Patchwork-Id: 13558574 Received: from smtpout.efficios.com (smtpout.efficios.com [167.114.26.122]) (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 4711B133285; Thu, 15 Feb 2024 14:46:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=167.114.26.122 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708008405; cv=none; b=c5UKq5GocFYYNFKslQDaKwH3JHKQgtHsYJEa6RY466D2fkow2XOgssRwjj8KOPEnc1hx1vPG4pOoCiVDiC6hDnhh74PEMVrZ768Y4cfF6UxhBXUBm3V8Iv6tKFQTUi2fmrMh47V6QLxOjtb2wP7cJ/hzia9qA4o96mooizY9XWc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1708008405; c=relaxed/simple; bh=+A5CzyStXl3uuRu7VAvAaofgyGw3Ro+0xr6rIKIjCf8=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=u+jBCYiGrGRGReNoIxsMl4445FHlthHFUjnFJLAhspg1potzoXSuz3OQoaWgARMpZ2dlZ6/mtDNq38G+YBGPPJ3ae6G8ppdWGbjDN86VPZ/wfeRGOoVqM7VqcxYYS10Bqe8Z5jBDCZjFpkJbWtYoxtMxMPhbfP+o8gat8hSGxc0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com; spf=pass smtp.mailfrom=efficios.com; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b=YtP1iOrG; arc=none smtp.client-ip=167.114.26.122 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=efficios.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=efficios.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="YtP1iOrG" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=efficios.com; s=smtpout1; t=1708008401; bh=+A5CzyStXl3uuRu7VAvAaofgyGw3Ro+0xr6rIKIjCf8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YtP1iOrGBZ2DFcfkMrFn0KrohYHueOZWWxnb1yMeBkD/1lvsW2xGteSYalPZKSM84 dPZuexmp1ywRE4ZTQOjFAgKyIAvz+xWNg3zjhDySnvi/5JJ+HqV6yNHbJnIgA2V+Cz LrEIdoTvdqClLxE1CDwMu7BvH4kU+HynYTL8FGvWqQVF+ZUtTFmBtps3Fll4hy5iYb VWfnhivvj+Lue04BRQYIzFUyJj/QJixaTtTpM98rtcdyFCecmfELtoqdx9qmJ4d3Cn Wpo8Zfth0EElxlDfWMpTqDJD6h2d2p2Z/MvkLxve0QsVGqva4CwWkicSMaV5TpJXl8 BS4uFSpfm9ZuQ== Received: from thinkos.internal.efficios.com (192-222-143-198.qc.cable.ebox.net [192.222.143.198]) by smtpout.efficios.com (Postfix) with ESMTPSA id 4TbHvP59RfzZKm; Thu, 15 Feb 2024 09:46:41 -0500 (EST) From: Mathieu Desnoyers To: Dan Williams , Arnd Bergmann , Dave Chinner Cc: linux-kernel@vger.kernel.org, Mathieu Desnoyers , Andrew Morton , Linus Torvalds , Vishal Verma , Dave Jiang , Matthew Wilcox , Russell King , linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-xfs@vger.kernel.org, dm-devel@lists.linux.dev, nvdimm@lists.linux.dev, linux-s390@vger.kernel.org Subject: [PATCH v6 7/9] dax: Check for data cache aliasing at runtime Date: Thu, 15 Feb 2024 09:46:31 -0500 Message-Id: <20240215144633.96437-8-mathieu.desnoyers@efficios.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240215144633.96437-1-mathieu.desnoyers@efficios.com> References: <20240215144633.96437-1-mathieu.desnoyers@efficios.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Replace the following fs/Kconfig:FS_DAX dependency: depends on !(ARM || MIPS || SPARC) By a runtime check within alloc_dax(). This runtime check returns ERR_PTR(-EOPNOTSUPP) if the @ops parameter is non-NULL (which means the kernel is using an aliased mapping) on an architecture which has data cache aliasing. Change the return value from NULL to PTR_ERR(-EOPNOTSUPP) for CONFIG_DAX=n for consistency. This is done in preparation for using cpu_dcache_is_aliasing() in a following change which will properly support architectures which detect data cache aliasing at runtime. Fixes: d92576f1167c ("dax: does not work correctly with virtual aliasing caches") Signed-off-by: Mathieu Desnoyers Reviewed-by: Dan Williams Cc: Andrew Morton Cc: Linus Torvalds Cc: Dan Williams Cc: Vishal Verma Cc: Dave Jiang Cc: Matthew Wilcox Cc: Arnd Bergmann Cc: Russell King Cc: linux-arch@vger.kernel.org Cc: linux-cxl@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-xfs@vger.kernel.org Cc: dm-devel@lists.linux.dev Cc: nvdimm@lists.linux.dev --- drivers/dax/super.c | 10 ++++++++++ fs/Kconfig | 1 - 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index 205b888d45bf..ce5bffa86bba 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -450,6 +450,16 @@ struct dax_device *alloc_dax(void *private, const struct dax_operations *ops) dev_t devt; int minor; + /* + * Unavailable on architectures with virtually aliased data caches, + * except for device-dax (NULL operations pointer), which does + * not use aliased mappings from the kernel. + */ + if (ops && (IS_ENABLED(CONFIG_ARM) || + IS_ENABLED(CONFIG_MIPS) || + IS_ENABLED(CONFIG_SPARC))) + return ERR_PTR(-EOPNOTSUPP); + if (WARN_ON_ONCE(ops && !ops->zero_page_range)) return ERR_PTR(-EINVAL); diff --git a/fs/Kconfig b/fs/Kconfig index 42837617a55b..e5efdb3b276b 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -56,7 +56,6 @@ endif # BLOCK config FS_DAX bool "File system based Direct Access (DAX) support" depends on MMU - depends on !(ARM || MIPS || SPARC) depends on ZONE_DEVICE || FS_DAX_LIMITED select FS_IOMAP select DAX