From nobody Mon Feb 9 01:43:16 2026 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.10]) (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 9B0882356BE; Sun, 25 Jan 2026 03:35:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.10 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769312157; cv=none; b=KZyh6BFEMBcJtA/aNPvmhjEDMdZNXF9AxS9w8ua5uAweDwS6OtVxeiJB5xebnQXq5kXguKGoynUxCf20tpIbDxg6SmOlVEOh29KriYo/iX9VZzeUoHU2Lh20m2SKb/LQeK7xB2Q28Q0MObgiRY2LXfa0XguEcSQ5FNltvtf1lGY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1769312157; c=relaxed/simple; bh=GQ14vRAHcbbj8om56GF25rYzFUWGSeE2wTidcEC1vZU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=N53FrwuoYIqekrrOwekq/w6jSJMgGpAvtMqeulBGusc1nFlPMQHB43dejzxlaUNwWTvcgdpDv80mGjyeIkK4tnQVVnAoTgBbH96W/4J+fJwdBtbS6kt3/4WeNz9Cy9RGHbfDb4H2ch+xsDw3n6XG1C2nOCBG0UT1To5sqUtZBhw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=DwlWLcKV; arc=none smtp.client-ip=192.198.163.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="DwlWLcKV" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1769312155; x=1800848155; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=GQ14vRAHcbbj8om56GF25rYzFUWGSeE2wTidcEC1vZU=; b=DwlWLcKVgU+fsnwLA9YP5fj4m4th3vEdAii2TPoXyPfmYsN9wzTl/NFp FNF+tVy2FA3wHhSSCtwGMJXR+4SnODhC6EbyR7Esle/I4SF7BmhqKXjKc oXCH4yNCzLLDtXHXgYZxPBIS5tiCs1VYiA8Q7EJ6msa8UxgQbqpDBBR01 ARUqN3dBK3MwamFfs51b0fNNlnMPtj99v4/3wQJrozFxMq8pDhqCl7D2t lIkU3mn/6Gp2VQQGXHS0/ZdRNzJ9YoxbldY/PB1JmJ0f8Ut0DdVYQ83Oq LpRcAbJSOm3TVvtyQplEwc7wVW5RgR7m/fQar/BE47pmO5uJuQhwHPfMU A==; X-CSE-ConnectionGUID: j5Pmuw05RaK/SVGCO20t7A== X-CSE-MsgGUID: U0cKv/i8RAOZKDfb+iAw5g== X-IronPort-AV: E=McAfee;i="6800,10657,11681"; a="81887464" X-IronPort-AV: E=Sophos;i="6.21,252,1763452800"; d="scan'208";a="81887464" Received: from fmviesa003.fm.intel.com ([10.60.135.143]) by fmvoesa104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jan 2026 19:35:55 -0800 X-CSE-ConnectionGUID: lns0XCV+TNODYDu1Ja0FCA== X-CSE-MsgGUID: 91AaHQWjQ+GzdFYQIBIm0A== X-ExtLoop1: 1 Received: from jf5300-b11a338t.jf.intel.com ([10.242.51.115]) by fmviesa003.fm.intel.com with ESMTP; 24 Jan 2026 19:35:53 -0800 From: Kanchana P Sridhar To: linux-kernel@vger.kernel.org, linux-mm@kvack.org, hannes@cmpxchg.org, yosry.ahmed@linux.dev, nphamcs@gmail.com, chengming.zhou@linux.dev, usamaarif642@gmail.com, ryan.roberts@arm.com, 21cnbao@gmail.com, ying.huang@linux.alibaba.com, akpm@linux-foundation.org, senozhatsky@chromium.org, sj@kernel.org, kasong@tencent.com, linux-crypto@vger.kernel.org, herbert@gondor.apana.org.au, davem@davemloft.net, clabbe@baylibre.com, ardb@kernel.org, ebiggers@google.com, surenb@google.com, kristen.c.accardi@intel.com, vinicius.gomes@intel.com, giovanni.cabiddu@intel.com Cc: wajdi.k.feghali@intel.com, kanchana.p.sridhar@intel.com Subject: [PATCH v14 11/26] crypto: iaa - Expect a single scatterlist for a [de]compress request's src/dst. Date: Sat, 24 Jan 2026 19:35:22 -0800 Message-Id: <20260125033537.334628-12-kanchana.p.sridhar@intel.com> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20260125033537.334628-1-kanchana.p.sridhar@intel.com> References: <20260125033537.334628-1-kanchana.p.sridhar@intel.com> 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" The calls to dma_map_sg() were passing sg_nents() for the @nents parameter, then error-ing out if more than one @nr_sgs were returned. Furthermore, there are no use-cases for iaa_crypto that allow multiple SG lists to be mapped for dma at once. Moreover, as per Herbert's direction in [1] for the batching API from higher mm layers to interface with crypto using SG lists, batching within iaa_crypto will rely on there being exactly one SG list per "unit" of [de]compression in a batch, where the component SG lists are obtained by breaking down the @req->src and @req->dst. Given all of the above, this patch simplifies the design by expecting only 1 @nents in req->src and req->dst, which aligns with current and batching use cases that will be developed in subsequent patches. This alleviates the latency penalty of calling sg_nents() per [de]compress op submitted to the hardware. Some unlikely() annotations are added to conditionals in the core [de]compress routines to further improve latency per op. [1]: https://lore.kernel.org/all/aJ7Fk6RpNc815Ivd@gondor.apana.org.au/T/#m9= 9aea2ce3d284e6c5a3253061d97b08c4752a798 Signed-off-by: Kanchana P Sridhar --- drivers/crypto/intel/iaa/iaa_crypto_main.c | 54 +++++++++++----------- 1 file changed, 27 insertions(+), 27 deletions(-) diff --git a/drivers/crypto/intel/iaa/iaa_crypto_main.c b/drivers/crypto/in= tel/iaa/iaa_crypto_main.c index 1b44c0524692..aafa8d4afcf4 100644 --- a/drivers/crypto/intel/iaa/iaa_crypto_main.c +++ b/drivers/crypto/intel/iaa/iaa_crypto_main.c @@ -1521,11 +1521,11 @@ static int iaa_remap_for_verify(struct device *dev,= struct iaa_wq *iaa_wq, int ret =3D 0; int nr_sgs; =20 - dma_unmap_sg(dev, req->dst, sg_nents(req->dst), DMA_FROM_DEVICE); - dma_unmap_sg(dev, req->src, sg_nents(req->src), DMA_TO_DEVICE); + dma_unmap_sg(dev, req->dst, 1, DMA_FROM_DEVICE); + dma_unmap_sg(dev, req->src, 1, DMA_TO_DEVICE); =20 - nr_sgs =3D dma_map_sg(dev, req->src, sg_nents(req->src), DMA_FROM_DEVICE); - if (nr_sgs <=3D 0 || nr_sgs > 1) { + nr_sgs =3D dma_map_sg(dev, req->src, 1, DMA_FROM_DEVICE); + if (unlikely(nr_sgs <=3D 0 || nr_sgs > 1)) { dev_dbg(dev, "verify: couldn't map src sg for iaa device %d," " wq %d: ret=3D%d\n", iaa_wq->iaa_device->idxd->id, iaa_wq->wq->id, ret); @@ -1537,13 +1537,13 @@ static int iaa_remap_for_verify(struct device *dev,= struct iaa_wq *iaa_wq, " req->slen %d, sg_dma_len(sg) %d\n", *src_addr, nr_sgs, req->src, req->slen, sg_dma_len(req->src)); =20 - nr_sgs =3D dma_map_sg(dev, req->dst, sg_nents(req->dst), DMA_TO_DEVICE); - if (nr_sgs <=3D 0 || nr_sgs > 1) { + nr_sgs =3D dma_map_sg(dev, req->dst, 1, DMA_TO_DEVICE); + if (unlikely(nr_sgs <=3D 0 || nr_sgs > 1)) { dev_dbg(dev, "verify: couldn't map dst sg for iaa device %d," " wq %d: ret=3D%d\n", iaa_wq->iaa_device->idxd->id, iaa_wq->wq->id, ret); ret =3D -EIO; - dma_unmap_sg(dev, req->src, sg_nents(req->src), DMA_FROM_DEVICE); + dma_unmap_sg(dev, req->src, 1, DMA_FROM_DEVICE); goto out; } *dst_addr =3D sg_dma_address(req->dst); @@ -1711,14 +1711,14 @@ static void iaa_desc_complete(struct idxd_desc *idx= d_desc, err =3D -EIO; } =20 - dma_unmap_sg(dev, ctx->req->dst, sg_nents(ctx->req->dst), DMA_TO_DEVICE); - dma_unmap_sg(dev, ctx->req->src, sg_nents(ctx->req->src), DMA_FROM_DEVIC= E); + dma_unmap_sg(dev, ctx->req->dst, 1, DMA_TO_DEVICE); + dma_unmap_sg(dev, ctx->req->src, 1, DMA_FROM_DEVICE); =20 goto out; } err: - dma_unmap_sg(dev, ctx->req->dst, sg_nents(ctx->req->dst), DMA_FROM_DEVICE= ); - dma_unmap_sg(dev, ctx->req->src, sg_nents(ctx->req->src), DMA_TO_DEVICE); + dma_unmap_sg(dev, ctx->req->dst, 1, DMA_FROM_DEVICE); + dma_unmap_sg(dev, ctx->req->src, 1, DMA_TO_DEVICE); out: if (ret !=3D 0) dev_dbg(dev, "asynchronous %s failed ret=3D%d\n", @@ -2022,8 +2022,8 @@ static int iaa_comp_acompress(struct acomp_req *req) =20 dev =3D &wq->idxd->pdev->dev; =20 - nr_sgs =3D dma_map_sg(dev, req->src, sg_nents(req->src), DMA_TO_DEVICE); - if (nr_sgs <=3D 0 || nr_sgs > 1) { + nr_sgs =3D dma_map_sg(dev, req->src, 1, DMA_TO_DEVICE); + if (unlikely(nr_sgs <=3D 0 || nr_sgs > 1)) { dev_dbg(dev, "couldn't map src sg for iaa device %d," " wq %d: ret=3D%d\n", iaa_wq->iaa_device->idxd->id, iaa_wq->wq->id, ret); @@ -2032,8 +2032,8 @@ static int iaa_comp_acompress(struct acomp_req *req) } src_addr =3D sg_dma_address(req->src); =20 - nr_sgs =3D dma_map_sg(dev, req->dst, sg_nents(req->dst), DMA_FROM_DEVICE); - if (nr_sgs <=3D 0 || nr_sgs > 1) { + nr_sgs =3D dma_map_sg(dev, req->dst, 1, DMA_FROM_DEVICE); + if (unlikely(nr_sgs <=3D 0 || nr_sgs > 1)) { dev_dbg(dev, "couldn't map dst sg for iaa device %d," " wq %d: ret=3D%d\n", iaa_wq->iaa_device->idxd->id, iaa_wq->wq->id, ret); @@ -2059,18 +2059,18 @@ static int iaa_comp_acompress(struct acomp_req *req) if (ret) dev_dbg(dev, "asynchronous compress verification failed ret=3D%d\n", re= t); =20 - dma_unmap_sg(dev, req->dst, sg_nents(req->dst), DMA_TO_DEVICE); - dma_unmap_sg(dev, req->src, sg_nents(req->src), DMA_FROM_DEVICE); + dma_unmap_sg(dev, req->dst, 1, DMA_TO_DEVICE); + dma_unmap_sg(dev, req->src, 1, DMA_FROM_DEVICE); =20 goto out; } =20 - if (ret) + if (unlikely(ret)) dev_dbg(dev, "asynchronous compress failed ret=3D%d\n", ret); =20 - dma_unmap_sg(dev, req->dst, sg_nents(req->dst), DMA_FROM_DEVICE); + dma_unmap_sg(dev, req->dst, 1, DMA_FROM_DEVICE); err_map_dst: - dma_unmap_sg(dev, req->src, sg_nents(req->src), DMA_TO_DEVICE); + dma_unmap_sg(dev, req->src, 1, DMA_TO_DEVICE); out: percpu_ref_put(&iaa_wq->ref); =20 @@ -2103,8 +2103,8 @@ static int iaa_comp_adecompress(struct acomp_req *req) =20 dev =3D &wq->idxd->pdev->dev; =20 - nr_sgs =3D dma_map_sg(dev, req->src, sg_nents(req->src), DMA_TO_DEVICE); - if (nr_sgs <=3D 0 || nr_sgs > 1) { + nr_sgs =3D dma_map_sg(dev, req->src, 1, DMA_TO_DEVICE); + if (unlikely(nr_sgs <=3D 0 || nr_sgs > 1)) { dev_dbg(dev, "couldn't map src sg for iaa device %d," " wq %d: ret=3D%d\n", iaa_wq->iaa_device->idxd->id, iaa_wq->wq->id, ret); @@ -2113,8 +2113,8 @@ static int iaa_comp_adecompress(struct acomp_req *req) } src_addr =3D sg_dma_address(req->src); =20 - nr_sgs =3D dma_map_sg(dev, req->dst, sg_nents(req->dst), DMA_FROM_DEVICE); - if (nr_sgs <=3D 0 || nr_sgs > 1) { + nr_sgs =3D dma_map_sg(dev, req->dst, 1, DMA_FROM_DEVICE); + if (unlikely(nr_sgs <=3D 0 || nr_sgs > 1)) { dev_dbg(dev, "couldn't map dst sg for iaa device %d," " wq %d: ret=3D%d\n", iaa_wq->iaa_device->idxd->id, iaa_wq->wq->id, ret); @@ -2128,12 +2128,12 @@ static int iaa_comp_adecompress(struct acomp_req *r= eq) if (ret =3D=3D -EINPROGRESS) return ret; =20 - if (ret !=3D 0) + if (unlikely(ret !=3D 0)) dev_dbg(dev, "asynchronous decompress failed ret=3D%d\n", ret); =20 - dma_unmap_sg(dev, req->dst, sg_nents(req->dst), DMA_FROM_DEVICE); + dma_unmap_sg(dev, req->dst, 1, DMA_FROM_DEVICE); err_map_dst: - dma_unmap_sg(dev, req->src, sg_nents(req->src), DMA_TO_DEVICE); + dma_unmap_sg(dev, req->src, 1, DMA_TO_DEVICE); out: percpu_ref_put(&iaa_wq->ref); =20 --=20 2.27.0