From nobody Tue Feb 10 05:17:51 2026 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 953801DDC30 for ; Mon, 27 Jan 2025 23:22:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738020151; cv=none; b=BtlCo+DjBLOJx2OS3WUtR0FFX7yFw3Ypp3Q1nbN1g5W5CUYNJc6Ejk+H3pCHtSU8CDmGK12T88cYZRazMo5j3hvx9SKwhL4bymfgDvNcV4Ovc8EcJoV7jDwgrzHKzGuQkFHjJ3qf1q7ysPHnbPtbEysGuHBQM/lhpUdCT+Kz7uE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738020151; c=relaxed/simple; bh=iIVz0iaFnVdC85TvJU7bWEbfgairNIkAhFvDjYIxMbk=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=o6fraf4/gVkBGblJaO+D84luXQD0B+WLaoRDp+MHDVYe5V5GnaifJ6wUMdZ/sxZRyR12l+LANu+qP22ey39v30PBcTblt4jR/+m3WfQf3GZZLV+BykD5V4GV232W/FURJZdaoH43qgc2ymQNQ/o6T35C7nYCK6MJeFu1tGxD45Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--fvdl.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=NV5Axanp; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--fvdl.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="NV5Axanp" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-21638389f63so75606055ad.1 for ; Mon, 27 Jan 2025 15:22:29 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1738020149; x=1738624949; darn=vger.kernel.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=dXf4/6vVFsOQWOL4yP6AMC2Up5+2J9mezQuBbeYawcA=; b=NV5AxanpGTPKE2svJEeFxEBuavTTev+inAhjJBomQBV/deZT978GSKOttAngSnHT7X vSJN7CQqBGWBDEvI2yWe81FmurtJdD5fvylkrDBYmHePN/HtIfqAk79jaocIbRnnEAKy ovALf906N2x3Um3mt8253+hGc84MV9pQjyjEZry3i1uVdD9WFNJx2lP//bBkGCPCwn9q vwj/aX3Rh0AJLiadx6nnUf9evrrWNfxsG7k7fwb7VuOWR7+tYYaIW6E9kZy+Z915cce7 IxTvoZVbNG7uFZDIR3wHasUGsDRWYgCjDUonVhhHKB6rr3iT7l/hFAoLNv59nRIaX6NG FyyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1738020149; x=1738624949; 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=dXf4/6vVFsOQWOL4yP6AMC2Up5+2J9mezQuBbeYawcA=; b=NKkk7+IYpvO9Jpl5mQJGeYcif86pVeOOYgQQaW1hebKyWblRasaGyvhfZ6kLcvSvWi LbmlXOeyf3lG0TIP5aQOgwRD6WRuEMGfH+ZsrwaC49Zg/ohSpjWYPCNJaGr54dwirOVy 6Tzz6regMpW8CXPs1Et7cCL5Lf0mwGzoD5NYynP78XGp+e/tBO2q5yE7eUVOMo4W4pgE twF+l2oC9wmd9DY5lORVUtgkcJ1VVqEs6FKgdgYJnBknW4xDtIhGRmTzAPSjndLEh+Hc 9XOzV3dxtKLpe8OuenbV0b6MxKCPKrgU1KWpu4/ecV8hsFH942ptt1Ri/23fVzYP4NOj CD9A== X-Forwarded-Encrypted: i=1; AJvYcCUHX5dL65/wjrZti+ntyxlOhtfKwL2SPGrxeRaVO4DsK5DUfqnZ8aTMEW40n/TBfBNoOoDXZE2yMBXwNus=@vger.kernel.org X-Gm-Message-State: AOJu0YwxiWUhdPmf2CH6SlkEiSQMjI1o7gFM7Bz59pFUIWpmW90kQfai bkGETev2ihVnCGUr8UBVGvSKJwLsUHPdjPOnR982LcsNNrUQEEAYyos284LZOIWPTMEYTA== X-Google-Smtp-Source: AGHT+IHacT0c2glOz6iHxFPEkg2efzrTP0CNHsnhpI9lKFAWHWkywal7QfbYZsPNCZVylM+1koVThcNB X-Received: from pfbcg7.prod.google.com ([2002:a05:6a00:2907:b0:728:aad0:33a4]) (user=fvdl job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:8411:b0:1e7:6f82:3217 with SMTP id adf61e73a8af0-1eb21465271mr67484709637.3.1738020148864; Mon, 27 Jan 2025 15:22:28 -0800 (PST) Date: Mon, 27 Jan 2025 23:21:43 +0000 In-Reply-To: <20250127232207.3888640-1-fvdl@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20250127232207.3888640-1-fvdl@google.com> X-Mailer: git-send-email 2.48.1.262.g85cc9f2d1e-goog Message-ID: <20250127232207.3888640-4-fvdl@google.com> Subject: [PATCH 03/27] mm/cma: introduce cma_intersects function From: Frank van der Linden To: akpm@linux-foundation.org, muchun.song@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: yuzhao@google.com, usama.arif@bytedance.com, joao.m.martins@oracle.com, roman.gushchin@linux.dev, Frank van der Linden , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , linux-s390@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Now that CMA areas can have multiple physical ranges, code can't assume a CMA struct represents a base_pfn plus a size, as returned from cma_get_base. Most cases are ok though, since they all explicitly refer to CMA areas that were created using existing interfaces (cma_declare_contiguous_nid or cma_init_reserved_mem), which guarantees they have just one physical range. An exception is the s390 code, which walks all CMA ranges to see if they intersect with a range of memory that is about to be hotremoved. So, in the future, it might run in to multi-range areas. To keep this check working, define a cma_intersects function. This just checks if a physaddr range intersects any of the ranges. Use it in the s390 check. Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: linux-s390@vger.kernel.org Signed-off-by: Frank van der Linden --- arch/s390/mm/init.c | 13 +++++-------- include/linux/cma.h | 1 + mm/cma.c | 21 +++++++++++++++++++++ 3 files changed, 27 insertions(+), 8 deletions(-) diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c index f2298f7a3f21..d88cb1c13f7d 100644 --- a/arch/s390/mm/init.c +++ b/arch/s390/mm/init.c @@ -239,16 +239,13 @@ struct s390_cma_mem_data { static int s390_cma_check_range(struct cma *cma, void *data) { struct s390_cma_mem_data *mem_data; - unsigned long start, end; =20 mem_data =3D data; - start =3D cma_get_base(cma); - end =3D start + cma_get_size(cma); - if (end < mem_data->start) - return 0; - if (start >=3D mem_data->end) - return 0; - return -EBUSY; + + if (cma_intersects(cma, mem_data->start, mem_data->end)) + return -EBUSY; + + return 0; } =20 static int s390_cma_mem_notifier(struct notifier_block *nb, diff --git a/include/linux/cma.h b/include/linux/cma.h index 863427c27dc2..03d85c100dcc 100644 --- a/include/linux/cma.h +++ b/include/linux/cma.h @@ -53,6 +53,7 @@ extern bool cma_pages_valid(struct cma *cma, const struct= page *pages, unsigned extern bool cma_release(struct cma *cma, const struct page *pages, unsigne= d long count); =20 extern int cma_for_each_area(int (*it)(struct cma *cma, void *data), void = *data); +extern bool cma_intersects(struct cma *cma, unsigned long start, unsigned = long end); =20 extern void cma_reserve_pages_on_error(struct cma *cma); =20 diff --git a/mm/cma.c b/mm/cma.c index c20255161642..1704d5be6a07 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -988,3 +988,24 @@ int cma_for_each_area(int (*it)(struct cma *cma, void = *data), void *data) =20 return 0; } + +bool cma_intersects(struct cma *cma, unsigned long start, unsigned long en= d) +{ + int r; + struct cma_memrange *cmr; + unsigned long rstart, rend; + + for (r =3D 0; r < cma->nranges; r++) { + cmr =3D &cma->ranges[r]; + + rstart =3D PFN_PHYS(cmr->base_pfn); + rend =3D PFN_PHYS(cmr->base_pfn + cmr->count); + if (end < rstart) + continue; + if (start >=3D rend) + continue; + return true; + } + + return false; +} --=20 2.48.1.262.g85cc9f2d1e-goog