From nobody Wed Oct 8 05:16:15 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 83D3B303DF9 for ; Wed, 2 Jul 2025 17:36:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751477780; cv=none; b=NvtoNwojat1YxNPt84H+5sX+FXe2IwJq4yeeSfyYf10VLLEJn8iJdSlNfDVk5R5KFF7eUjMdMRLMaTBX0RbdqFo3c/uwCKkdkesXy3GqPYeOMD3SYPLMu5do/+T2pR5dcFK3+OCUZEAcTocTBIPbBFylJiE3YzX64dq8M3dWA+E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751477780; c=relaxed/simple; bh=NqKk8ngarG6g3EyeYQKPZPq7rwSgnU5mnxeVmbW10t0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VKhWAsFbin3jCRL4eX/yFXfpOFQWD8TxVIBbEyYo4ON2sVIOXMNWxMypXbASluwZXTmIidZvPl/qVc5p6BhwS8OuHS3HnApjXaxm8IBdTg9k5YtA+KezRKOQmJ6W0e5WGbIo7W6qRt2y+BktRcQH/uOv+py6pcL0FZWzzHiUHvE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=vQleZpGg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="vQleZpGg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A365C4CEEE; Wed, 2 Jul 2025 17:36:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1751477780; bh=NqKk8ngarG6g3EyeYQKPZPq7rwSgnU5mnxeVmbW10t0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vQleZpGgNy3mRTy5dbm9tOQSQllRNd7C7MW0izMjJH9NSe7mbO92fQJ0qQUrNG2R2 2dIWbQ1ryYr6OTjjqOP5P3arqEyF2pAUeb1rHo+D1daavMkQN2y7kXt/V9IBRCneJY XRE7FNsbSaTMWKkw15gykIINHiFYjQ6TEjSLcBUS4TVVcGMjBKE/VnrzrJ5iABejga +4QMO6t9+bbz4kDf9Kqt00H7L3dEOFkyjj4DuZYQsGl6oSHR97tFHEBZLTzCnrBzA+ zKP74NX5aLNUqsRFVdYFODDbnG27smcrw3eGree46NKcn5WyuA+5aAhuK5cFuhMBi+ n4oL+U2o1vUqg== From: Mike Rapoport To: Andrew Morton Cc: Alexandre Ghiti , David Hildenbrand , Mike Rapoport , Oscar Salvador , Pratyush Yadav , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 3/3] cma: move allocation from HIGHMEM to a helper function Date: Wed, 2 Jul 2025 20:36:05 +0300 Message-ID: <20250702173605.2198924-4-rppt@kernel.org> X-Mailer: git-send-email 2.47.2 In-Reply-To: <20250702173605.2198924-1-rppt@kernel.org> References: <20250702173605.2198924-1-rppt@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Mike Rapoport (Microsoft)" When CONFIG_HIGMEM is enabled, __cma_declare_contiguous_nid() first tries to allocate the area from HIGHMEM and if that fails it falls back to allocation from low memory. Split allocation from HIGMEM into a helper function to further decouple logic related to CONFIG_HIGHMEM. Signed-off-by: Mike Rapoport (Microsoft) --- mm/cma.c | 52 +++++++++++++++++++++++++++++----------------------- 1 file changed, 29 insertions(+), 23 deletions(-) diff --git a/mm/cma.c b/mm/cma.c index 1df8ff312d99..0a24c46f3296 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -376,6 +376,30 @@ static int __init cma_fixed_reserve(phys_addr_t base, = phys_addr_t size) return 0; } =20 +static phys_addr_t __init cma_alloc_highmem(phys_addr_t base, phys_addr_t = size, + phys_addr_t align, phys_addr_t *limit, int nid) +{ + phys_addr_t addr =3D 0; + + if (IS_ENABLED(CONFIG_HIGHMEM)) { + phys_addr_t highmem =3D __pa(high_memory - 1) + 1; + + /* + * All pages in the reserved area must come from the same zone. + * If the requested region crosses the low/high memory boundary, + * try allocating from high memory first and fall back to low + * memory in case of failure. + */ + if (base < highmem && *limit > highmem) { + addr =3D memblock_alloc_range_nid(size, align, highmem, + *limit, nid, true); + *limit =3D highmem; + } + } + + return addr; +} + static int __init __cma_declare_contiguous_nid(phys_addr_t *basep, phys_addr_t size, phys_addr_t limit, phys_addr_t alignment, unsigned int order_per_bit, @@ -383,19 +407,9 @@ static int __init __cma_declare_contiguous_nid(phys_ad= dr_t *basep, int nid) { phys_addr_t memblock_end =3D memblock_end_of_DRAM(); - phys_addr_t highmem_start, base =3D *basep; + phys_addr_t base =3D *basep; int ret; =20 - /* - * We can't use __pa(high_memory) directly, since high_memory - * isn't a valid direct map VA, and DEBUG_VIRTUAL will (validly) - * complain. Find the boundary by adding one to the last valid - * address. - */ - if (IS_ENABLED(CONFIG_HIGHMEM)) - highmem_start =3D __pa(high_memory - 1) + 1; - else - highmem_start =3D memblock_end_of_DRAM(); pr_debug("%s(size %pa, base %pa, limit %pa alignment %pa)\n", __func__, &size, &base, &limit, &alignment); =20 @@ -472,18 +486,10 @@ static int __init __cma_declare_contiguous_nid(phys_a= ddr_t *basep, } #endif =20 - /* - * All pages in the reserved area must come from the same zone. - * If the requested region crosses the low/high memory boundary, - * try allocating from high memory first and fall back to low - * memory in case of failure. - */ - if (!addr && base < highmem_start && limit > highmem_start) { - addr =3D memblock_alloc_range_nid(size, alignment, - highmem_start, limit, nid, true); - limit =3D highmem_start; - } - + /* On systems with HIGHMEM try allocating from there first */ + if (!addr) + addr =3D cma_alloc_highmem(base, size, alignment, &limit, + nid); if (!addr) { addr =3D memblock_alloc_range_nid(size, alignment, base, limit, nid, true); --=20 2.47.2