From patchwork Wed Aug 9 12:17:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Boris Brezillon X-Patchwork-Id: 13347871 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9C285EB64DD for ; Wed, 9 Aug 2023 12:18:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=MGq6z9un8hAq082OxLMcLFKG9ItNjP3Sj9aM0XLbAXQ=; b=fcqq742RWz3AG9 QGHxcvd8933FlvGY3nhAuc2tKP+lgOAUOXgw9JH7PgioH6gGs6ZJvUrIRLqy3Ji1ITr1fqNsFtgRB Fm9AUccw2rwA/LG58BY3xuEDa4o3bSM75fMhTTH8nx9A7K57D7Vk2tiqmWX1c++eGI7Db5QHBUokY lEmgS+Au16xM6gtO/iH5gsBAvny6ZmkcvLdeII7rtOIClVCRb6srpr7kJB0EzE3IU0m7+YgHWT7wH URzOTmaJCmP1kojnrRZSfAIMr1NaZGYRXDydRekQzIfi/4ZlMNXQMs5BEwm9hXr/hKOA94iNp+pB/ eEI+WDcdjVEbbXc388MQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qTi8U-004sNI-35; Wed, 09 Aug 2023 12:17:58 +0000 Received: from madras.collabora.co.uk ([46.235.227.172]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qTi8S-004sM4-09 for linux-arm-kernel@lists.infradead.org; Wed, 09 Aug 2023 12:17:57 +0000 Received: from localhost.localdomain (unknown [IPv6:2a01:e0a:2c:6930:5cf4:84a1:2763:fe0d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bbrezillon) by madras.collabora.co.uk (Postfix) with ESMTPSA id 7901B66071FA; Wed, 9 Aug 2023 13:17:49 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1691583469; bh=xrsJr8/Wzr/bxAh467gukIAWjJA0qC+z2qCOAesp6lw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=eMYmzQDtJIT9UIqCa1YkXi1htwVjleAcBfQcnJFANA/Lp/NKMvB0Nnk7hF4/087PS SYEcsD2dZnC6CvCGIS7FDIf9cuck8WUo3lkKNEloZG4CP9czchlB76Q65QQrkaVjYm 4CEM3VUPnKOa1GXaeVIHzq7Eh4s+h4RKCRGYZsVqrQHIAETR7zgINZNhqBeQTWp0sX XQvvUWi/Jx+hG+AJMZHNVBevwZ+zZDFZDTNcR2cYjSp4WEnDcS7WUr7srwS+Ez2yFc hwPABz+fmD7BaImhweVi7cwmFysrOjs9FGNtV9GZHIBon267sYI03lwVrPvCXDVN/O fDQpyhN4+mOLA== From: Boris Brezillon To: Joerg Roedel , iommu@lists.linux.dev, Will Deacon , Robin Murphy , linux-arm-kernel@lists.infradead.org Cc: Rob Clark , Boris Brezillon Subject: [PATCH 1/2] iommu: Allow passing custom allocators to pgtable drivers Date: Wed, 9 Aug 2023 14:17:43 +0200 Message-ID: <20230809121744.2341454-2-boris.brezillon@collabora.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809121744.2341454-1-boris.brezillon@collabora.com> References: <20230809121744.2341454-1-boris.brezillon@collabora.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230809_051756_249252_21AAC476 X-CRM114-Status: GOOD ( 17.23 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org This will be useful for GPU drivers who want to keep page tables in a pool so they can: - keep freed page tables in a free pool and speed-up upcoming page table allocations - batch page table allocation instead of allocating one page at a time - pre-reserve pages for page tables needed for map/unmap operations, to ensure map/unmap operations don't try to allocate memory in paths they're allowed to block or fail We will extend the Arm LPAE format to support custom allocators in a separate commit. Signed-off-by: Boris Brezillon --- drivers/iommu/io-pgtable.c | 19 +++++++++++++++++++ include/linux/io-pgtable.h | 21 +++++++++++++++++++++ 2 files changed, 40 insertions(+) diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c index b843fcd365d2..f4caf630638a 100644 --- a/drivers/iommu/io-pgtable.c +++ b/drivers/iommu/io-pgtable.c @@ -34,6 +34,22 @@ io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = { #endif }; +static int check_custom_allocator(enum io_pgtable_fmt fmt, + struct io_pgtable_cfg *cfg) +{ + /* When passing a custom allocator, both the alloc and free + * functions should be provided. + */ + if ((cfg->alloc != NULL) != (cfg->free != NULL)) + return -EINVAL; + + /* No custom allocator, no need to check the format. */ + if (!cfg->alloc) + return 0; + + return -EINVAL; +} + struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, struct io_pgtable_cfg *cfg, void *cookie) @@ -44,6 +60,9 @@ struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt, if (fmt >= IO_PGTABLE_NUM_FMTS) return NULL; + if (check_custom_allocator(fmt, cfg)) + return NULL; + fns = io_pgtable_init_table[fmt]; if (!fns) return NULL; diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h index 1b7a44b35616..80d05dcb0f4c 100644 --- a/include/linux/io-pgtable.h +++ b/include/linux/io-pgtable.h @@ -100,6 +100,27 @@ struct io_pgtable_cfg { const struct iommu_flush_ops *tlb; struct device *iommu_dev; + /** + * @alloc: Custom page allocator. + * + * Optional hook used to allocate page tables. If this function is NULL, + * @free must be NULL too. + * + * Not all formats support custom page allocators. Before considering + * passing a non-NULL value, make sure the chosen page format supports + * this feature. + */ + void *(*alloc)(void *cookie, size_t size, gfp_t gfp); + + /** + * @free: Custom page de-allocator. + * + * Optional hook used to free page tables allocated with the @alloc + * hook. Must be non-NULL if @alloc is not NULL, must be NULL + * otherwise. + */ + void (*free)(void *cookie, void *pages, size_t size); + /* Low-level data specific to the table format */ union { struct {