From patchwork Mon Mar 6 09:43:25 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anup Patel X-Patchwork-Id: 9605559 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 0F3176016C for ; Mon, 6 Mar 2017 09:44:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D0ECF279B3 for ; Mon, 6 Mar 2017 09:44:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C3C1628346; Mon, 6 Mar 2017 09:44:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.3 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, RCVD_IN_SORBS_SPAM, T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F2778279B3 for ; Mon, 6 Mar 2017 09:44:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754195AbdCFJow (ORCPT ); Mon, 6 Mar 2017 04:44:52 -0500 Received: from mail-qk0-f175.google.com ([209.85.220.175]:34692 "EHLO mail-qk0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754119AbdCFJob (ORCPT ); Mon, 6 Mar 2017 04:44:31 -0500 Received: by mail-qk0-f175.google.com with SMTP id p64so25647388qke.1 for ; Mon, 06 Mar 2017 01:44:13 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=H5vkioEwfr9XgZDZWyjDFyTJ7W36ua5lYRyKwpD5J0c=; b=Le22+Bf9aPpIhs+XVsxjMZTTYz24Dm6iYbNqPFSenMxFhQkIGtVi6vWrF+yZML9a5H j9S8WnYj7sjsylZeduO5sWs/ZcVOFOTpKUKO8rEwQv/T75+Ai6Gx0qrfGYM6oh/DE4xX VEsJOzGRNzGdG8LJZInc4ygLWTXHtHBz1zbHc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=H5vkioEwfr9XgZDZWyjDFyTJ7W36ua5lYRyKwpD5J0c=; b=hRQD02sZj7zF9VMHbQtJrM1RvhVi9UimHltDOk1w6qZz7fI7gV/A6RXd0WKQJ93Ydm ZjvKjpF69RLFULWntgH7f1GCGUFSsyGWsVwxaysX1x1cR9tIyK6qf4zRMXV41ccjhfuX gJOVQ9P3Z1+P6VLCglbxx6Wsa05tvSsqYdWYropfJDbPJsGxSsUN1WUuhZV8v7CwR9Od 2/BPeHZlzv+oAVQXZ6y20MfKRWSRxOZYOjkqMO4B5hRY0F1zaCIuq7rEVcpB6MLshVwo YYpK109f3C2tmYcXkR1mzpRxYZRQqSSPTrlTAVVDyji87sWevmDHmkwzz/PIOdQAChnr DQvA== X-Gm-Message-State: AMke39kp9qPx5woFgLkQC9vZxAwq+QuO73Y62JZQ5T9XnHllLOtXv/tMWEgQWYW0ZcaoCV5L X-Received: by 10.200.56.48 with SMTP id q45mr15316084qtb.220.1488793447670; Mon, 06 Mar 2017 01:44:07 -0800 (PST) Received: from anup-HP-Compaq-8100-Elite-CMT-PC.dhcp.avagotech.net ([192.19.237.250]) by smtp.gmail.com with ESMTPSA id q66sm13017276qkd.69.2017.03.06.01.44.01 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 06 Mar 2017 01:44:07 -0800 (PST) From: Anup Patel To: Vinod Koul , Rob Herring , Mark Rutland , Herbert Xu , "David S . Miller" , Jassi Brar Cc: Dan Williams , Ray Jui , Scott Branden , Jon Mason , Rob Rice , bcm-kernel-feedback-list@broadcom.com, dmaengine@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, linux-raid@vger.kernel.org, Anup Patel Subject: [PATCH v6 1/4] lib/raid6: Add log-of-2 table for RAID6 HW requiring disk position Date: Mon, 6 Mar 2017 15:13:25 +0530 Message-Id: <1488793408-25592-2-git-send-email-anup.patel@broadcom.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1488793408-25592-1-git-send-email-anup.patel@broadcom.com> References: <1488793408-25592-1-git-send-email-anup.patel@broadcom.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The raid6_gfexp table represents {2}^n values for 0 <= n < 256. The Linux async_tx framework pass values from raid6_gfexp as coefficients for each source to prep_dma_pq() callback of DMA channel with PQ capability. This creates problem for RAID6 offload engines (such as Broadcom SBA) which take disk position (i.e. log of {2}) instead of multiplicative cofficients from raid6_gfexp table. This patch adds raid6_gflog table having log-of-2 value for any given x such that 0 <= x < 256. For any given disk coefficient x, the corresponding disk position is given by raid6_gflog[x]. The RAID6 offload engine driver can use this newly added raid6_gflog table to get disk position from multiplicative coefficient. Signed-off-by: Anup Patel Reviewed-by: Scott Branden Reviewed-by: Ray Jui --- include/linux/raid/pq.h | 1 + lib/raid6/mktables.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/include/linux/raid/pq.h b/include/linux/raid/pq.h index 4d57bba..30f9453 100644 --- a/include/linux/raid/pq.h +++ b/include/linux/raid/pq.h @@ -142,6 +142,7 @@ int raid6_select_algo(void); extern const u8 raid6_gfmul[256][256] __attribute__((aligned(256))); extern const u8 raid6_vgfmul[256][32] __attribute__((aligned(256))); extern const u8 raid6_gfexp[256] __attribute__((aligned(256))); +extern const u8 raid6_gflog[256] __attribute__((aligned(256))); extern const u8 raid6_gfinv[256] __attribute__((aligned(256))); extern const u8 raid6_gfexi[256] __attribute__((aligned(256))); diff --git a/lib/raid6/mktables.c b/lib/raid6/mktables.c index 39787db..e824d08 100644 --- a/lib/raid6/mktables.c +++ b/lib/raid6/mktables.c @@ -125,6 +125,26 @@ int main(int argc, char *argv[]) printf("EXPORT_SYMBOL(raid6_gfexp);\n"); printf("#endif\n"); + /* Compute log-of-2 table */ + printf("\nconst u8 __attribute__((aligned(256)))\n" + "raid6_gflog[256] =\n" "{\n"); + for (i = 0; i < 256; i += 8) { + printf("\t"); + for (j = 0; j < 8; j++) { + v = 255; + for (k = 0; k < 256; k++) + if (exptbl[k] == (i + j)) { + v = k; + break; + } + printf("0x%02x,%c", v, (j == 7) ? '\n' : ' '); + } + } + printf("};\n"); + printf("#ifdef __KERNEL__\n"); + printf("EXPORT_SYMBOL(raid6_gflog);\n"); + printf("#endif\n"); + /* Compute inverse table x^-1 == x^254 */ printf("\nconst u8 __attribute__((aligned(256)))\n" "raid6_gfinv[256] =\n" "{\n");