From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-20.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 42152C07E9D for ; Mon, 19 Jul 2021 12:32:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 262C76113E for ; Mon, 19 Jul 2021 12:32:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236990AbhGSLvS (ORCPT ); Mon, 19 Jul 2021 07:51:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:60206 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236811AbhGSLvM (ORCPT ); Mon, 19 Jul 2021 07:51:12 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7C41E61165; Mon, 19 Jul 2021 12:31:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1626697912; bh=x+RB9Am0+UBxmf5N8DpwjNIkOrkArDEapjosy245dTs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GojP7K0bbgsAdV7B1R/j02xfvFlzKE9PyrTaREI0SRY8tnXaQdCDp885U75S9QhCC CjXXsQ9dkFV5MV9SCacMNJfUrO49s7Z9OhkUQsppNCW+0dQd3d2mtyhwlu2yvoOPRy Mcw4iJ7/R0wECavN6hhBD2xIJR3lYKcETsgfyxOQxouDm1rEp7GobfD9WzSyNtEU1I j09mKS9Q9mJyXTwMyruQPkTcJvj48gvcsdrRIvZMYuh2xzncfd1btzTuGp8HYUO/BI nzOjMGRy0UIXeCxEQuUoVH1fFGOKFAMiVbGMsMMUFd0miXlW/eS1DaBHUqez2PnusZ VTIse+uqnbV/g== From: Will Deacon To: iommu@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, Will Deacon , Guenter Roeck , Claire Chang , Christoph Hellwig , Robin Murphy , Konrad Rzeszutek Wilk , Nathan Chancellor Subject: [PATCH 3/5] swiotlb: Remove io_tlb_default_mem indirection Date: Mon, 19 Jul 2021 13:30:52 +0100 Message-Id: <20210719123054.6844-4-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210719123054.6844-1-will@kernel.org> References: <20210719123054.6844-1-will@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The indirection from the global 'io_tlb_default_mem' pointer to the static '_io_tlb_default_mem' structure is ugly and unnecessary. Convert all users to reference the static structure directly, using the 'nslabs' field to determine whether swiotlb has been initialised. Cc: Claire Chang Cc: Christoph Hellwig Cc: Robin Murphy Cc: Konrad Rzeszutek Wilk Tested-by: Nathan Chancellor Signed-off-by: Will Deacon --- drivers/base/core.c | 2 +- drivers/xen/swiotlb-xen.c | 4 ++-- include/linux/swiotlb.h | 2 +- kernel/dma/swiotlb.c | 38 ++++++++++++++++++-------------------- 4 files changed, 22 insertions(+), 24 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index ea5b85354526..b49824001cfa 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -2848,7 +2848,7 @@ void device_initialize(struct device *dev) dev->dma_coherent = dma_default_coherent; #endif #ifdef CONFIG_SWIOTLB - dev->dma_io_tlb_mem = io_tlb_default_mem; + dev->dma_io_tlb_mem = &io_tlb_default_mem; #endif } EXPORT_SYMBOL_GPL(device_initialize); diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 785ec7e8be01..f06d9b4f1e0f 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -164,7 +164,7 @@ int __ref xen_swiotlb_init(void) int rc = -ENOMEM; char *start; - if (io_tlb_default_mem != NULL) { + if (io_tlb_default_mem.nslabs) { pr_warn("swiotlb buffer already initialized\n"); return -EEXIST; } @@ -547,7 +547,7 @@ xen_swiotlb_sync_sg_for_device(struct device *dev, struct scatterlist *sgl, static int xen_swiotlb_dma_supported(struct device *hwdev, u64 mask) { - return xen_phys_to_dma(hwdev, io_tlb_default_mem->end - 1) <= mask; + return xen_phys_to_dma(hwdev, io_tlb_default_mem.end - 1) <= mask; } const struct dma_map_ops xen_swiotlb_dma_ops = { diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index d3b617c19045..b0cb2a9973f4 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -105,7 +105,7 @@ struct io_tlb_mem { unsigned int list; } *slots; }; -extern struct io_tlb_mem *io_tlb_default_mem; +extern struct io_tlb_mem io_tlb_default_mem; static inline bool is_swiotlb_buffer(struct device *dev, phys_addr_t paddr) { diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 992d73cdc944..7948f274f9bb 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -70,8 +70,7 @@ enum swiotlb_force swiotlb_force; -struct io_tlb_mem *io_tlb_default_mem; -static struct io_tlb_mem _io_tlb_default_mem; +struct io_tlb_mem io_tlb_default_mem; /* * Max segment that we can provide which (if pages are contingous) will @@ -102,7 +101,7 @@ early_param("swiotlb", setup_io_tlb_npages); unsigned int swiotlb_max_segment(void) { - return io_tlb_default_mem ? max_segment : 0; + return io_tlb_default_mem.nslabs ? max_segment : 0; } EXPORT_SYMBOL_GPL(swiotlb_max_segment); @@ -135,9 +134,9 @@ void __init swiotlb_adjust_size(unsigned long size) void swiotlb_print_info(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; - if (!mem) { + if (!mem->nslabs) { pr_warn("No low mem\n"); return; } @@ -164,11 +163,11 @@ static inline unsigned long nr_slots(u64 val) */ void __init swiotlb_update_mem_attributes(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; void *vaddr; unsigned long bytes; - if (!mem || mem->late_alloc) + if (!mem->nslabs || mem->late_alloc) return; vaddr = phys_to_virt(mem->start); bytes = PAGE_ALIGN(mem->nslabs << IO_TLB_SHIFT); @@ -202,14 +201,14 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem *mem, phys_addr_t start, int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) { - struct io_tlb_mem *mem = &_io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; size_t alloc_size; if (swiotlb_force == SWIOTLB_NO_FORCE) return 0; /* protect against double initialization */ - if (WARN_ON_ONCE(io_tlb_default_mem)) + if (WARN_ON_ONCE(mem->nslabs)) return -ENOMEM; alloc_size = PAGE_ALIGN(array_size(sizeof(*mem->slots), nslabs)); @@ -220,7 +219,6 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long nslabs, int verbose) swiotlb_init_io_tlb_mem(mem, __pa(tlb), nslabs, false); - io_tlb_default_mem = mem; if (verbose) swiotlb_print_info(); swiotlb_set_max_segment(mem->nslabs << IO_TLB_SHIFT); @@ -305,14 +303,14 @@ swiotlb_late_init_with_default_size(size_t default_size) int swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) { - struct io_tlb_mem *mem = &_io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; unsigned long bytes = nslabs << IO_TLB_SHIFT; if (swiotlb_force == SWIOTLB_NO_FORCE) return 0; /* protect against double initialization */ - if (WARN_ON_ONCE(io_tlb_default_mem)) + if (WARN_ON_ONCE(mem->nslabs)) return -ENOMEM; mem->slots = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, @@ -323,7 +321,6 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) set_memory_decrypted((unsigned long)tlb, bytes >> PAGE_SHIFT); swiotlb_init_io_tlb_mem(mem, virt_to_phys(tlb), nslabs, true); - io_tlb_default_mem = mem; swiotlb_print_info(); swiotlb_set_max_segment(mem->nslabs << IO_TLB_SHIFT); return 0; @@ -331,10 +328,10 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs) void __init swiotlb_exit(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; size_t size; + struct io_tlb_mem *mem = &io_tlb_default_mem; - if (!mem) + if (!mem->nslabs) return; size = array_size(sizeof(*mem->slots), mem->nslabs); @@ -342,7 +339,6 @@ void __init swiotlb_exit(void) free_pages((unsigned long)mem->slots, get_order(size)); else memblock_free_late(__pa(mem->slots), PAGE_ALIGN(size)); - io_tlb_default_mem = NULL; memset(mem, 0, sizeof(*mem)); } @@ -697,7 +693,9 @@ size_t swiotlb_max_mapping_size(struct device *dev) bool is_swiotlb_active(struct device *dev) { - return dev->dma_io_tlb_mem != NULL; + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; + + return mem && mem->nslabs; } EXPORT_SYMBOL_GPL(is_swiotlb_active); @@ -712,10 +710,10 @@ static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem) static int __init swiotlb_create_default_debugfs(void) { - struct io_tlb_mem *mem = io_tlb_default_mem; + struct io_tlb_mem *mem = &io_tlb_default_mem; debugfs_dir = debugfs_create_dir("swiotlb", NULL); - if (mem) { + if (mem->nslabs) { mem->debugfs = debugfs_dir; swiotlb_create_debugfs_files(mem); } @@ -814,7 +812,7 @@ static int rmem_swiotlb_device_init(struct reserved_mem *rmem, static void rmem_swiotlb_device_release(struct reserved_mem *rmem, struct device *dev) { - dev->dma_io_tlb_mem = io_tlb_default_mem; + dev->dma_io_tlb_mem = &io_tlb_default_mem; } static const struct reserved_mem_ops rmem_swiotlb_ops = { -- 2.32.0.402.g57bb445576-goog