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 X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F319FC38A24 for ; Thu, 7 May 2020 11:01:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D77A32083B for ; Thu, 7 May 2020 11:01:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726558AbgEGLBQ (ORCPT ); Thu, 7 May 2020 07:01:16 -0400 Received: from relay7-d.mail.gandi.net ([217.70.183.200]:38477 "EHLO relay7-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726382AbgEGLBQ (ORCPT ); Thu, 7 May 2020 07:01:16 -0400 X-Originating-IP: 91.224.148.103 Received: from localhost.localdomain (unknown [91.224.148.103]) (Authenticated sender: miquel.raynal@bootlin.com) by relay7-d.mail.gandi.net (Postfix) with ESMTPSA id 366D620009; Thu, 7 May 2020 11:01:00 +0000 (UTC) From: Miquel Raynal To: Rob Herring , Mark Rutland , , Richard Weinberger , Vignesh Raghavendra , Tudor Ambarus , Cc: Thomas Petazzoni , Boris Brezillon , Michal Simek , Naga Sureshkumar Relli , Miquel Raynal , Ivan Djelic Subject: [PATCH v3 2/8] lib/bch: Allow easy bit swapping Date: Thu, 7 May 2020 13:00:28 +0200 Message-Id: <20200507110034.14736-3-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200507110034.14736-1-miquel.raynal@bootlin.com> References: <20200507110034.14736-1-miquel.raynal@bootlin.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org From: Boris Brezillon It seems that several hardware ECC engine use a swapped representation of bytes compared to software. It means that when the software BCH engine is working in conjunction with data generated with hardware, we must swap the bits inside bytes, eg: 0x0A = b0000_1010 -> b0101_0000 = 0x50 Make it possible just by flipping a boolean in the BCH control structure. Signed-off-by: Boris Brezillon Signed-off-by: Miquel Raynal Cc: Ivan Djelic --- include/linux/bch.h | 1 + lib/bch.c | 84 ++++++++++++++++++++++++++++++++++++++------- 2 files changed, 72 insertions(+), 13 deletions(-) diff --git a/include/linux/bch.h b/include/linux/bch.h index 9c35e7cd5890..c42f50cacfdc 100644 --- a/include/linux/bch.h +++ b/include/linux/bch.h @@ -51,6 +51,7 @@ struct bch_control { int *cache; struct gf_poly *elp; struct gf_poly *poly_2t[4]; + bool swap_bits; }; struct bch_control *bch_init(int m, int t, unsigned int prim_poly); diff --git a/lib/bch.c b/lib/bch.c index 1091841ac716..81bf8b426eea 100644 --- a/lib/bch.c +++ b/lib/bch.c @@ -114,6 +114,49 @@ struct gf_poly_deg1 { unsigned int c[2]; }; +static u8 swap_bits_table[] = { + 0x00, 0x80, 0x40, 0xc0, 0x20, 0xa0, 0x60, 0xe0, + 0x10, 0x90, 0x50, 0xd0, 0x30, 0xb0, 0x70, 0xf0, + 0x08, 0x88, 0x48, 0xc8, 0x28, 0xa8, 0x68, 0xe8, + 0x18, 0x98, 0x58, 0xd8, 0x38, 0xb8, 0x78, 0xf8, + 0x04, 0x84, 0x44, 0xc4, 0x24, 0xa4, 0x64, 0xe4, + 0x14, 0x94, 0x54, 0xd4, 0x34, 0xb4, 0x74, 0xf4, + 0x0c, 0x8c, 0x4c, 0xcc, 0x2c, 0xac, 0x6c, 0xec, + 0x1c, 0x9c, 0x5c, 0xdc, 0x3c, 0xbc, 0x7c, 0xfc, + 0x02, 0x82, 0x42, 0xc2, 0x22, 0xa2, 0x62, 0xe2, + 0x12, 0x92, 0x52, 0xd2, 0x32, 0xb2, 0x72, 0xf2, + 0x0a, 0x8a, 0x4a, 0xca, 0x2a, 0xaa, 0x6a, 0xea, + 0x1a, 0x9a, 0x5a, 0xda, 0x3a, 0xba, 0x7a, 0xfa, + 0x06, 0x86, 0x46, 0xc6, 0x26, 0xa6, 0x66, 0xe6, + 0x16, 0x96, 0x56, 0xd6, 0x36, 0xb6, 0x76, 0xf6, + 0x0e, 0x8e, 0x4e, 0xce, 0x2e, 0xae, 0x6e, 0xee, + 0x1e, 0x9e, 0x5e, 0xde, 0x3e, 0xbe, 0x7e, 0xfe, + 0x01, 0x81, 0x41, 0xc1, 0x21, 0xa1, 0x61, 0xe1, + 0x11, 0x91, 0x51, 0xd1, 0x31, 0xb1, 0x71, 0xf1, + 0x09, 0x89, 0x49, 0xc9, 0x29, 0xa9, 0x69, 0xe9, + 0x19, 0x99, 0x59, 0xd9, 0x39, 0xb9, 0x79, 0xf9, + 0x05, 0x85, 0x45, 0xc5, 0x25, 0xa5, 0x65, 0xe5, + 0x15, 0x95, 0x55, 0xd5, 0x35, 0xb5, 0x75, 0xf5, + 0x0d, 0x8d, 0x4d, 0xcd, 0x2d, 0xad, 0x6d, 0xed, + 0x1d, 0x9d, 0x5d, 0xdd, 0x3d, 0xbd, 0x7d, 0xfd, + 0x03, 0x83, 0x43, 0xc3, 0x23, 0xa3, 0x63, 0xe3, + 0x13, 0x93, 0x53, 0xd3, 0x33, 0xb3, 0x73, 0xf3, + 0x0b, 0x8b, 0x4b, 0xcb, 0x2b, 0xab, 0x6b, 0xeb, + 0x1b, 0x9b, 0x5b, 0xdb, 0x3b, 0xbb, 0x7b, 0xfb, + 0x07, 0x87, 0x47, 0xc7, 0x27, 0xa7, 0x67, 0xe7, + 0x17, 0x97, 0x57, 0xd7, 0x37, 0xb7, 0x77, 0xf7, + 0x0f, 0x8f, 0x4f, 0xcf, 0x2f, 0xaf, 0x6f, 0xef, + 0x1f, 0x9f, 0x5f, 0xdf, 0x3f, 0xbf, 0x7f, 0xff, +}; + +static u8 swap_bits(struct bch_control *bch, u8 in) +{ + if (!bch->swap_bits) + return in; + + return swap_bits_table[in]; +} + /* * same as bch_encode(), but process input data one byte at a time */ @@ -126,7 +169,9 @@ static void bch_encode_unaligned(struct bch_control *bch, const int l = BCH_ECC_WORDS(bch)-1; while (len--) { - p = bch->mod8_tab + (l+1)*(((ecc[0] >> 24)^(*data++)) & 0xff); + u8 tmp = swap_bits(bch, *data++); + + p = bch->mod8_tab + (l+1)*(((ecc[0] >> 24)^(tmp)) & 0xff); for (i = 0; i < l; i++) ecc[i] = ((ecc[i] << 8)|(ecc[i+1] >> 24))^(*p++); @@ -145,10 +190,16 @@ static void load_ecc8(struct bch_control *bch, uint32_t *dst, unsigned int i, nwords = BCH_ECC_WORDS(bch)-1; for (i = 0; i < nwords; i++, src += 4) - dst[i] = (src[0] << 24)|(src[1] << 16)|(src[2] << 8)|src[3]; + dst[i] = ((u32)swap_bits(bch, src[0]) << 24) | + ((u32)swap_bits(bch, src[1]) << 16) | + ((u32)swap_bits(bch, src[2]) << 8) | + swap_bits(bch, src[3]); memcpy(pad, src, BCH_ECC_BYTES(bch)-4*nwords); - dst[nwords] = (pad[0] << 24)|(pad[1] << 16)|(pad[2] << 8)|pad[3]; + dst[nwords] = ((u32)swap_bits(bch, pad[0]) << 24) | + ((u32)swap_bits(bch, pad[1]) << 16) | + ((u32)swap_bits(bch, pad[2]) << 8) | + swap_bits(bch, pad[3]); } /* @@ -161,15 +212,15 @@ static void store_ecc8(struct bch_control *bch, uint8_t *dst, unsigned int i, nwords = BCH_ECC_WORDS(bch)-1; for (i = 0; i < nwords; i++) { - *dst++ = (src[i] >> 24); - *dst++ = (src[i] >> 16) & 0xff; - *dst++ = (src[i] >> 8) & 0xff; - *dst++ = (src[i] >> 0) & 0xff; + *dst++ = swap_bits(bch, src[i] >> 24); + *dst++ = swap_bits(bch, src[i] >> 16); + *dst++ = swap_bits(bch, src[i] >> 8); + *dst++ = swap_bits(bch, src[i]); } - pad[0] = (src[nwords] >> 24); - pad[1] = (src[nwords] >> 16) & 0xff; - pad[2] = (src[nwords] >> 8) & 0xff; - pad[3] = (src[nwords] >> 0) & 0xff; + pad[0] = swap_bits(bch, src[nwords] >> 24); + pad[1] = swap_bits(bch, src[nwords] >> 16); + pad[2] = swap_bits(bch, src[nwords] >> 8); + pad[3] = swap_bits(bch, src[nwords]); memcpy(dst, pad, BCH_ECC_BYTES(bch)-4*nwords); } @@ -240,7 +291,12 @@ void bch_encode(struct bch_control *bch, const uint8_t *data, */ while (mlen--) { /* input data is read in big-endian format */ - w = r[0]^cpu_to_be32(*pdata++); + w = cpu_to_be32(*pdata++); + w = (u32)swap_bits(bch, w) | + ((u32)swap_bits(bch, w >> 8) << 8) | + ((u32)swap_bits(bch, w >> 16) << 16) | + ((u32)swap_bits(bch, w >> 24) << 24); + w ^= r[0]; p0 = tab0 + (l+1)*((w >> 0) & 0xff); p1 = tab1 + (l+1)*((w >> 8) & 0xff); p2 = tab2 + (l+1)*((w >> 16) & 0xff); @@ -1048,7 +1104,9 @@ int bch_decode(struct bch_control *bch, const uint8_t *data, unsigned int len, break; } errloc[i] = nbits-1-errloc[i]; - errloc[i] = (errloc[i] & ~7)|(7-(errloc[i] & 7)); + if (!bch->swap_bits) + errloc[i] = (errloc[i] & ~7) | + (7-(errloc[i] & 7)); } } return (err >= 0) ? err : -EBADMSG; -- 2.20.1