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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D71CDCCF9E9 for ; Sun, 26 Oct 2025 20:36:40 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C21E98E0186; Sun, 26 Oct 2025 16:36:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A9BE78E0184; Sun, 26 Oct 2025 16:36:35 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 89FF68E0186; Sun, 26 Oct 2025 16:36:35 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 674958E0184 for ; Sun, 26 Oct 2025 16:36:35 -0400 (EDT) Received: from smtpin19.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 29BE7B833B for ; Sun, 26 Oct 2025 20:36:35 +0000 (UTC) X-FDA: 84041423550.19.2B97717 Received: from mail-yw1-f202.google.com (mail-yw1-f202.google.com [209.85.128.202]) by imf18.hostedemail.com (Postfix) with ESMTP id 5CEB11C000A for ; Sun, 26 Oct 2025 20:36:33 +0000 (UTC) Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=mKfguIFw; spf=pass (imf18.hostedemail.com: domain of 3UIb-aAYKCKUXZWJSGLTTLQJ.HTRQNSZc-RRPaFHP.TWL@flex--surenb.bounces.google.com designates 209.85.128.202 as permitted sender) smtp.mailfrom=3UIb-aAYKCKUXZWJSGLTTLQJ.HTRQNSZc-RRPaFHP.TWL@flex--surenb.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1761510993; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ldBBc2e1dfbyRaOTMu7xgu9ZtisaUPfuPL5Tr5iIwBM=; b=CATobxl3d9Ru1bLoYCHhzt02eBfLzcVU9mrcjClF6ga5cFZBnnWN0Q+2yPb1Zt61wNQ9Ek 5DFgTOU9ADwFjRvX9xXZp5gTCf23Cgfa/sT5ahwsRgDZXu0vrznO1RC+y0G2BMRfbF/4TX iP2jpf5P7Dh/n8IN8a6cG5v7+af/GSs= ARC-Authentication-Results: i=1; imf18.hostedemail.com; dkim=pass header.d=google.com header.s=20230601 header.b=mKfguIFw; spf=pass (imf18.hostedemail.com: domain of 3UIb-aAYKCKUXZWJSGLTTLQJ.HTRQNSZc-RRPaFHP.TWL@flex--surenb.bounces.google.com designates 209.85.128.202 as permitted sender) smtp.mailfrom=3UIb-aAYKCKUXZWJSGLTTLQJ.HTRQNSZc-RRPaFHP.TWL@flex--surenb.bounces.google.com; dmarc=pass (policy=reject) header.from=google.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1761510993; a=rsa-sha256; cv=none; b=Db9C0PNEDD/Bd2ETqoDPR4Z/xkOKp35Z/KnVkMhdKSIXEkpq5t6ZRAKpG8eg/LwQoYK6It rVGps/3ncjykymBgqwtpaIpURldi+U7urHsWymb63mIQxgmOtaj6+1t83XP9ECgJpxr5pi F/KiVFqztAJ8NbzCgiSSige1RmS2tK4= Received: by mail-yw1-f202.google.com with SMTP id 00721157ae682-7849f67aa1cso49514527b3.1 for ; Sun, 26 Oct 2025 13:36:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1761510992; x=1762115792; darn=kvack.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=ldBBc2e1dfbyRaOTMu7xgu9ZtisaUPfuPL5Tr5iIwBM=; b=mKfguIFwGmvHAjOOcB+OqHcSeKYBzUiehDLge6wqqtHRzgjI18vNJOQudpwBmTAbvt UnydSqBvgtPxn2oJaqZpqS2PHVi5AOJrlyJW2lS8sL4I1ZKuWFJB7ipW1v/RdBQdFujr VJvpOPal4MZS3r5ssMs5jutjcHKOgdFlk1r3sHyKyjAPxlJw4yVvtAxsn92dLS9xj6x/ jxAGkBNs1JYMRBj4FP9cUV5ZFNvi9ZLvo0ocQYsOHDwcUVtNL/W8Q4vLD+qrzsjnuEhj hhbl8QdYFQu00fX/3W+XvAUxRLZTiaPri9oRi+lOLLPAHYxElx2nhbKuEjs4vOvyNTMt kIVQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1761510992; x=1762115792; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=ldBBc2e1dfbyRaOTMu7xgu9ZtisaUPfuPL5Tr5iIwBM=; b=H5yqsrLCW1vdCIElDoaBwSE3VXeVe1RU+TSR73790MMcU7jfGhzFQ5MpdLBHCgLyLm 2k4ap2ZzKXr8a/hGj9qI6StxJ1dW3+Qb2tgO1OOycfcJclVc1IQXIHOTnBIEE2Ja0E2z B62svAOuQlApcws2rkrakQxjrnqzbErJ899KdDJopiWOu57aSK9Ydwe+IV9YKAAAIdi1 aCoZV6Wu2ikH8/Edl3mNbdpZApN+9qAvIiDBlFrmsAl6OxYGb63TG2NavGeH76M2d9mH yk5nvQof6/jBvPnqq9Pv7qhiPQiF4px+2GKATsIf/mZRe5e4iU/KEyRXVwSCbpihh114 k0Vw== X-Forwarded-Encrypted: i=1; AJvYcCX0lpqwmHFGQL187RiDDswa9ycubw6xjh8JFPz8NJPWFygD5AGhx1OPq9FTdnAtQhBAHY81ftskbw==@kvack.org X-Gm-Message-State: AOJu0Yz9ju64HfCEkLzPYLpu9RHs2yvXzNEFFrgvzUoJbvDQawkuN2NA k4jY1fkROx0zgDVPW3JneiNhab1OPD83qP5f+fYHsk3dveTJiEdYCevRcDhaBAtb8KP1Za/5P/1 6Wb3mjQ== X-Google-Smtp-Source: AGHT+IHTjjYIfLTQVYwrbFnLFzysSRA0cI7//o4uCjgZD63uA+e+/DxWUL27OlXKaVk1obVSWsBkcP+KEyM= X-Received: from yxf19.prod.google.com ([2002:a53:b113:0:b0:63f:2d9a:6526]) (user=surenb job=prod-delivery.src-stubby-dispatcher) by 2002:a53:b118:0:b0:635:4ecf:bdc6 with SMTP id 956f58d0204a3-63f435602d0mr7203026d50.40.1761510992511; Sun, 26 Oct 2025 13:36:32 -0700 (PDT) Date: Sun, 26 Oct 2025 13:36:11 -0700 In-Reply-To: <20251026203611.1608903-1-surenb@google.com> Mime-Version: 1.0 References: <20251026203611.1608903-1-surenb@google.com> X-Mailer: git-send-email 2.51.1.851.g4ebd6896fd-goog Message-ID: <20251026203611.1608903-9-surenb@google.com> Subject: [PATCH v2 8/8] mm: integrate GCMA with CMA using dt-bindings From: Suren Baghdasaryan To: akpm@linux-foundation.org Cc: david@redhat.com, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, vbabka@suse.cz, alexandru.elisei@arm.com, peterx@redhat.com, sj@kernel.org, rppt@kernel.org, mhocko@suse.com, corbet@lwn.net, axboe@kernel.dk, viro@zeniv.linux.org.uk, brauner@kernel.org, hch@infradead.org, jack@suse.cz, willy@infradead.org, m.szyprowski@samsung.com, robin.murphy@arm.com, hannes@cmpxchg.org, zhengqi.arch@bytedance.com, shakeel.butt@linux.dev, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, minchan@kernel.org, surenb@google.com, linux-mm@kvack.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, iommu@lists.linux.dev, Minchan Kim Content-Type: text/plain; charset="UTF-8" X-Stat-Signature: jhtm7z191u3puhwotu8xnz57gwm5u4f5 X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 5CEB11C000A X-HE-Tag: 1761510993-502145 X-HE-Meta: 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 xNh1RFPU 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Introduce a new "guarantee" property for shared-dma-pool to enable GCMA-backed memory pools. Memory allocations from such pools will have low latency and will be guaranteed to succeed as long as there is contiguous space inside the reservation. dt-schema for shared-dma-pool [1] will need to be updated once this patch is accepted. [1] https://github.com/devicetree-org/dt-schema/blob/main/dtschema/schemas/reserved-memory/shared-dma-pool.yaml Signed-off-by: Minchan Kim Signed-off-by: Suren Baghdasaryan --- include/linux/cma.h | 11 +++++++++-- kernel/dma/contiguous.c | 11 ++++++++++- mm/Kconfig | 2 +- mm/cma.c | 37 +++++++++++++++++++++++++++---------- mm/cma.h | 1 + mm/cma_sysfs.c | 10 ++++++++++ mm/gcma.c | 2 +- 7 files changed, 59 insertions(+), 15 deletions(-) diff --git a/include/linux/cma.h b/include/linux/cma.h index 62d9c1cf6326..3ec2e76a8666 100644 --- a/include/linux/cma.h +++ b/include/linux/cma.h @@ -43,10 +43,17 @@ static inline int __init cma_declare_contiguous(phys_addr_t base, extern int __init cma_declare_contiguous_multi(phys_addr_t size, phys_addr_t align, unsigned int order_per_bit, const char *name, struct cma **res_cma, int nid); -extern int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, +extern int __cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, unsigned int order_per_bit, const char *name, - struct cma **res_cma); + struct cma **res_cma, bool gcma); +static inline int cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, + unsigned int order_per_bit, + const char *name, + struct cma **res_cma) +{ + return __cma_init_reserved_mem(base, size, order_per_bit, name, res_cma, false); +} extern struct page *cma_alloc(struct cma *cma, unsigned long count, unsigned int align, bool no_warn); extern bool cma_pages_valid(struct cma *cma, const struct page *pages, unsigned long count); diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c index d9b9dcba6ff7..73a699ef0377 100644 --- a/kernel/dma/contiguous.c +++ b/kernel/dma/contiguous.c @@ -461,6 +461,7 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem) unsigned long node = rmem->fdt_node; bool default_cma = of_get_flat_dt_prop(node, "linux,cma-default", NULL); struct cma *cma; + bool gcma; int err; if (size_cmdline != -1 && default_cma) { @@ -478,7 +479,15 @@ static int __init rmem_cma_setup(struct reserved_mem *rmem) return -EINVAL; } - err = cma_init_reserved_mem(rmem->base, rmem->size, 0, rmem->name, &cma); + gcma = !!of_get_flat_dt_prop(node, "guarantee", NULL); +#ifndef CONFIG_GCMA + if (gcma) { + pr_err("Reserved memory: unable to setup GCMA region, GCMA is not enabled\n"); + return -EINVAL; + } +#endif + err = __cma_init_reserved_mem(rmem->base, rmem->size, 0, rmem->name, + &cma, gcma); if (err) { pr_err("Reserved memory: unable to setup CMA region\n"); return err; diff --git a/mm/Kconfig b/mm/Kconfig index 3166fde83340..1c8b20d90790 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1099,7 +1099,7 @@ config CMA_AREAS config GCMA bool "GCMA (Guaranteed Contiguous Memory Allocator)" - depends on CLEANCACHE + depends on CLEANCACHE && CMA help This enables the Guaranteed Contiguous Memory Allocator to allow low latency guaranteed contiguous memory allocations. Memory diff --git a/mm/cma.c b/mm/cma.c index 813e6dc7b095..71fb494ef2a4 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -28,6 +28,7 @@ #include #include #include +#include #include #include "internal.h" @@ -161,11 +162,18 @@ static void __init cma_activate_area(struct cma *cma) count = early_pfn[r] - cmr->base_pfn; bitmap_count = cma_bitmap_pages_to_bits(cma, count); bitmap_set(cmr->bitmap, 0, bitmap_count); + } else { + count = 0; } - for (pfn = early_pfn[r]; pfn < cmr->base_pfn + cmr->count; - pfn += pageblock_nr_pages) - init_cma_reserved_pageblock(pfn_to_page(pfn)); + if (cma->gcma) { + gcma_register_area(cma->name, early_pfn[r], + cma->count - count); + } else { + for (pfn = early_pfn[r]; pfn < cmr->base_pfn + cmr->count; + pfn += pageblock_nr_pages) + init_cma_reserved_pageblock(pfn_to_page(pfn)); + } } spin_lock_init(&cma->lock); @@ -252,7 +260,7 @@ static void __init cma_drop_area(struct cma *cma) } /** - * cma_init_reserved_mem() - create custom contiguous area from reserved memory + * __cma_init_reserved_mem() - create custom contiguous area from reserved memory * @base: Base address of the reserved area * @size: Size of the reserved area (in bytes), * @order_per_bit: Order of pages represented by one bit on bitmap. @@ -260,13 +268,14 @@ static void __init cma_drop_area(struct cma *cma) * the area will be set to "cmaN", where N is a running counter of * used areas. * @res_cma: Pointer to store the created cma region. + * @gcma: Flag to reserve guaranteed reserved memory area. * * This function creates custom contiguous area from already reserved memory. */ -int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, - unsigned int order_per_bit, - const char *name, - struct cma **res_cma) +int __init __cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, + unsigned int order_per_bit, + const char *name, + struct cma **res_cma, bool gcma) { struct cma *cma; int ret; @@ -297,6 +306,7 @@ int __init cma_init_reserved_mem(phys_addr_t base, phys_addr_t size, cma->ranges[0].count = cma->count; cma->nranges = 1; cma->nid = NUMA_NO_NODE; + cma->gcma = gcma; *res_cma = cma; @@ -836,7 +846,11 @@ static int cma_range_alloc(struct cma *cma, struct cma_memrange *cmr, spin_unlock_irq(&cma->lock); mutex_lock(&cma->alloc_mutex); - ret = alloc_contig_range(pfn, pfn + count, ACR_FLAGS_CMA, gfp); + if (cma->gcma) + ret = gcma_alloc_range(pfn, count, gfp); + else + ret = alloc_contig_range(pfn, pfn + count, + ACR_FLAGS_CMA, gfp); mutex_unlock(&cma->alloc_mutex); if (!ret) break; @@ -1009,7 +1023,10 @@ bool cma_release(struct cma *cma, const struct page *pages, if (r == cma->nranges) return false; - free_contig_range(pfn, count); + if (cma->gcma) + gcma_free_range(pfn, count); + else + free_contig_range(pfn, count); cma_clear_bitmap(cma, cmr, pfn, count); cma_sysfs_account_release_pages(cma, count); trace_cma_release(cma->name, pfn, pages, count); diff --git a/mm/cma.h b/mm/cma.h index c70180c36559..3b09e8619082 100644 --- a/mm/cma.h +++ b/mm/cma.h @@ -49,6 +49,7 @@ struct cma { char name[CMA_MAX_NAME]; int nranges; struct cma_memrange ranges[CMA_MAX_RANGES]; + bool gcma; #ifdef CONFIG_CMA_SYSFS /* the number of CMA page successful allocations */ atomic64_t nr_pages_succeeded; diff --git a/mm/cma_sysfs.c b/mm/cma_sysfs.c index 97acd3e5a6a5..4ecc36270a4d 100644 --- a/mm/cma_sysfs.c +++ b/mm/cma_sysfs.c @@ -80,6 +80,15 @@ static ssize_t available_pages_show(struct kobject *kobj, } CMA_ATTR_RO(available_pages); +static ssize_t gcma_show(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) +{ + struct cma *cma = cma_from_kobj(kobj); + + return sysfs_emit(buf, "%d\n", cma->gcma); +} +CMA_ATTR_RO(gcma); + static void cma_kobj_release(struct kobject *kobj) { struct cma *cma = cma_from_kobj(kobj); @@ -95,6 +104,7 @@ static struct attribute *cma_attrs[] = { &release_pages_success_attr.attr, &total_pages_attr.attr, &available_pages_attr.attr, + &gcma_attr.attr, NULL, }; ATTRIBUTE_GROUPS(cma); diff --git a/mm/gcma.c b/mm/gcma.c index b86f82b8fe9d..fcf1d3c0283f 100644 --- a/mm/gcma.c +++ b/mm/gcma.c @@ -119,7 +119,7 @@ int gcma_register_area(const char *name, folio_set_count(folio, 0); list_add(&folio->lru, &folios); } - + folio_zone(pfn_folio(start_pfn))->cma_pages += count; cleancache_backend_put_folios(pool_id, &folios); spin_lock(&gcma_area_lock); -- 2.51.1.851.g4ebd6896fd-goog