From patchwork Mon Jul 24 12:12:41 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Petr Tesarik X-Patchwork-Id: 13324536 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A70EC001DF for ; Mon, 24 Jul 2023 12:15:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230121AbjGXMPn (ORCPT ); Mon, 24 Jul 2023 08:15:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45702 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229456AbjGXMPm (ORCPT ); Mon, 24 Jul 2023 08:15:42 -0400 Received: from frasgout11.his.huawei.com (unknown [14.137.139.23]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 06A4719BA; Mon, 24 Jul 2023 05:15:20 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.18.147.228]) by frasgout11.his.huawei.com (SkyGuard) with ESMTP id 4R8f2T0zZmz9ynSn; Mon, 24 Jul 2023 20:03:45 +0800 (CST) Received: from A2101119013HW2.china.huawei.com (unknown [10.81.222.124]) by APP2 (Coremail) with SMTP id GxC2BwA3_lTGar5ky0byBA--.27936S7; Mon, 24 Jul 2023 13:14:23 +0100 (CET) From: Petr Tesarik To: Stefano Stabellini , Russell King , Thomas Bogendoerfer , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)), "H. Peter Anvin" , Greg Kroah-Hartman , "Rafael J. Wysocki" , Juergen Gross , Oleksandr Tyshchenko , Christoph Hellwig , Marek Szyprowski , Robin Murphy , Jonathan Corbet , Andy Shevchenko , Hans de Goede , Sakari Ailus , James Seo , James Clark , Kees Cook , xen-devel@lists.xenproject.org (moderated list:XEN HYPERVISOR ARM), linux-arm-kernel@lists.infradead.org (moderated list:ARM PORT), linux-kernel@vger.kernel.org (open list), linux-mips@vger.kernel.org (open list:MIPS), iommu@lists.linux.dev (open list:XEN SWIOTLB SUBSYSTEM) Cc: Roberto Sassu , petr@tesarici.cz Subject: [PATCH v5 5/9] swiotlb: add a flag whether SWIOTLB is allowed to grow Date: Mon, 24 Jul 2023 14:12:41 +0200 Message-Id: <0c0c9033b48962930c66c0325bb385ce2744b8bd.1690200598.git.petr.tesarik.ext@huawei.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: MIME-Version: 1.0 X-CM-TRANSID: GxC2BwA3_lTGar5ky0byBA--.27936S7 X-Coremail-Antispam: 1UD129KBjvJXoWxWrW8XF1fKr1fZr13Wr4UArb_yoWrWryUpF 15XF4rtF4IqF1xArZ7Cw1xGF9akw4kKrW7urWa9ry5Ar43Jw1Yq3WDKayYq34Fqrs2qF4S qFyS9r1Ykr17ZwUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUml14x267AKxVWrJVCq3wAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2048vs2IY020E87I2jVAFwI0_JF0E3s1l82xGYI kIc2x26xkF7I0E14v26ryj6s0DM28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48ve4kI8wA2 z4x0Y4vE2Ix0cI8IcVAFwI0_JFI_Gr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI0_Gr1j6F 4UJwA2z4x0Y4vEx4A2jsIE14v26r4j6F4UM28EF7xvwVC2z280aVCY1x0267AKxVW8Jr0_ Cr1UM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6x IIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8JwAm72CE4IkC6x0Yz7v_Jr0_ Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAGYxC7M4IIrI8v6xkF7I0E8c xan2IY04v7MxkF7I0Ew4C26cxK6c8Ij28IcwCF04k20xvY0x0EwIxGrwCFx2IqxVCFs4IE 7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v26r106r1rMI 8E67AF67kF1VAFwI0_Wrv_Gr1UMIIYrxkI7VAKI48JMIIF0xvE2Ix0cI8IcVAFwI0_JFI_ Gr1lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4UJVWxJr1lIxAIcVCF04k26cxKx2IYs7xG6r 1j6r1xMIIF0xvEx4A2jsIE14v26r4j6F4UMIIF0xvEx4A2jsIEc7CjxVAFwI0_Gr1j6F4U JbIYCTnIWIevJa73UjIFyTuYvjfUnzVbDUUUU X-CM-SenderInfo: hshw23xhvd2x3n6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org From: Petr Tesarik Add a config option (CONFIG_SWIOTLB_DYNAMIC) to enable or disable dynamic allocation of additional bounce buffers. If this option is set, mark the default SWIOTLB as able to grow and restricted DMA pools as unable. However, if the address of the default memory pool is explicitly queried, make the default SWIOTLB also unable to grow. This is currently used to set up PCI BAR movable regions on some Octeon MIPS boards which may not be able to use a SWIOTLB pool elsewhere in physical memory. See octeon_pci_setup() for more details. If a remap function is specified, it must be also called on any dynamically allocated pools, but there are some issues: - The remap function may block, so it should not be called from an atomic context. - There is no corresponding unremap() function if the memory pool is freed. - The only in-tree implementation (xen_swiotlb_fixup) requires that the number of slots in the memory pool is a multiple of SWIOTLB_SEGSIZE. Keep it simple for now and disable growing the SWIOTLB if a remap function was specified. Signed-off-by: Petr Tesarik --- include/linux/swiotlb.h | 4 ++++ kernel/dma/Kconfig | 13 +++++++++++++ kernel/dma/swiotlb.c | 13 +++++++++++++ 3 files changed, 30 insertions(+) diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index fd01a0870b38..78a51d2f9f5c 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -100,6 +100,7 @@ struct io_tlb_pool { * @debugfs: The dentry to debugfs. * @force_bounce: %true if swiotlb bouncing is forced * @for_alloc: %true if the pool is used for memory allocation + * @can_grow: %true if more pools can be allocated dynamically. * @total_used: The total number of slots in the pool that are currently used * across all areas. Used only for calculating used_hiwater in * debugfs. @@ -112,6 +113,9 @@ struct io_tlb_mem { struct dentry *debugfs; bool force_bounce; bool for_alloc; +#ifdef CONFIG_SWIOTLB_DYNAMIC + bool can_grow; +#endif #ifdef CONFIG_DEBUG_FS atomic_long_t total_used; atomic_long_t used_hiwater; diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index 11d077003205..68c61fdf2b44 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -90,6 +90,19 @@ config SWIOTLB bool select NEED_DMA_MAP_STATE +config SWIOTLB_DYNAMIC + bool "Dynamic allocation of DMA bounce buffers" + default n + depends on SWIOTLB + help + This enables dynamic resizing of the software IO TLB. The kernel + starts with one memory pool at boot and it will allocate additional + pools as needed. To reduce run-time kernel memory requirements, you + may have to specify a smaller size of the initial pool using + "swiotlb=" on the kernel command line. + + If unsure, say N. + config DMA_BOUNCE_UNALIGNED_KMALLOC bool depends on SWIOTLB diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 11bacde00df7..5acb4552f869 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -330,6 +330,11 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags, io_tlb_default_mem.force_bounce = swiotlb_force_bounce || (flags & SWIOTLB_FORCE); +#ifdef CONFIG_SWIOTLB_DYNAMIC + if (!remap) + io_tlb_default_mem.can_grow = true; +#endif + if (!default_nareas) swiotlb_adjust_nareas(num_possible_cpus()); @@ -400,6 +405,11 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask, io_tlb_default_mem.force_bounce = swiotlb_force_bounce; +#ifdef CONFIG_SWIOTLB_DYNAMIC + if (!remap) + io_tlb_default_mem.can_grow = true; +#endif + if (!default_nareas) swiotlb_adjust_nareas(num_possible_cpus()); @@ -1066,6 +1076,9 @@ EXPORT_SYMBOL_GPL(is_swiotlb_active); */ phys_addr_t default_swiotlb_base(void) { +#ifdef CONFIG_SWIOTLB_DYNAMIC + io_tlb_default_mem.can_grow = false; +#endif return io_tlb_default_mem.defpool.start; }