From patchwork Sun May 3 07:18:51 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Baruch Siach X-Patchwork-Id: 467365 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2001:1868:205::9]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 56FCF1402A0 for ; Sun, 3 May 2015 17:25:06 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1YooFk-0001pU-Vr; Sun, 03 May 2015 07:23:52 +0000 Received: from guitar.tcltek.co.il ([192.115.133.116] helo=mx.tkos.co.il) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YooEb-0001KE-GY; Sun, 03 May 2015 07:22:45 +0000 Received: from tarshish.tkos.co.il (unknown [10.0.8.6]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mx.tkos.co.il (Postfix) with ESMTPSA id 1987E440842; Sun, 3 May 2015 10:22:15 +0300 (IDT) From: Baruch Siach To: David Woodhouse , Brian Norris Subject: [PATCH v2 1/4] mtd: nand: mxc_nand: cleanup copy_spare function Date: Sun, 3 May 2015 10:18:51 +0300 Message-Id: <782c879fdfa0125211fb1a3a2fcd143687c541fc.1430636819.git.baruch@tkos.co.il> X-Mailer: git-send-email 2.1.4 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150503_002242_050041_4BE397FD X-CRM114-Status: GOOD ( 14.83 ) X-Spam-Score: 0.0 (/) X-Spam-Report: SpamAssassin version 3.4.0 on bombadil.infradead.org summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- Cc: Fabio Estevam , Baruch Siach , linux-mtd@lists.infradead.org, Sascha Hauer , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Shawn Guo , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org From: Uwe Kleine-König To give people without the reference manual at hand a chance to understand how spare area is handled in the i.MX nand controller, improve commenting, naming of variables and coding style. No functional change intended. Signed-off-by: Uwe Kleine-König [baruch: declare oob_chunk_size; update comments; reword commit log] Signed-off-by: Baruch Siach --- drivers/mtd/nand/mxc_nand.c | 46 ++++++++++++++++++++++++++++++--------------- 1 file changed, 31 insertions(+), 15 deletions(-) diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c index 372e0e38f59b..33b22b9c0b30 100644 --- a/drivers/mtd/nand/mxc_nand.c +++ b/drivers/mtd/nand/mxc_nand.c @@ -807,32 +807,48 @@ static void mxc_nand_select_chip_v2(struct mtd_info *mtd, int chip) } /* - * Function to transfer data to/from spare area. + * The controller splits a page into data chunks of 512 bytes + partial oob. + * There are writesize / 512 such chunks, the size of the partial oob parts is + * oobsize / #chunks rounded down to a multiple of 2. The last oob chunk then + * contains additionally the byte lost by rounding (if any). + * This function handles the needed shuffling between host->data_buf (which + * holds a page in natural order, i.e. writesize bytes data + oobsize bytes + * spare) and the NFC buffer. */ static void copy_spare(struct mtd_info *mtd, bool bfrom) { struct nand_chip *this = mtd->priv; struct mxc_nand_host *host = this->priv; - u16 i, j; - u16 n = mtd->writesize >> 9; + u16 i, oob_chunk_size; + u16 num_chunks = mtd->writesize / 512; + u8 *d = host->data_buf + mtd->writesize; u8 __iomem *s = host->spare0; - u16 t = host->devtype_data->spare_len; + u16 sparebuf_size = host->devtype_data->spare_len; - j = (mtd->oobsize / n >> 1) << 1; + /* size of oob chunk for all but possibly the last one */ + oob_chunk_size = (mtd->oobsize / num_chunks) & ~1; if (bfrom) { - for (i = 0; i < n - 1; i++) - memcpy32_fromio(d + i * j, s + i * t, j); - - /* the last section */ - memcpy32_fromio(d + i * j, s + i * t, mtd->oobsize - i * j); + for (i = 0; i < num_chunks - 1; i++) + memcpy32_fromio(d + i * oob_chunk_size, + s + i * sparebuf_size, + oob_chunk_size); + + /* the last chunk */ + memcpy32_fromio(d + i * oob_chunk_size, + s + i * sparebuf_size, + mtd->oobsize - i * oob_chunk_size); } else { - for (i = 0; i < n - 1; i++) - memcpy32_toio(&s[i * t], &d[i * j], j); - - /* the last section */ - memcpy32_toio(&s[i * t], &d[i * j], mtd->oobsize - i * j); + for (i = 0; i < num_chunks - 1; i++) + memcpy32_toio(&s[i * sparebuf_size], + &d[i * oob_chunk_size], + oob_chunk_size); + + /* the last chunk */ + memcpy32_toio(&s[oob_chunk_size * sparebuf_size], + &d[i * oob_chunk_size], + mtd->oobsize - i * oob_chunk_size); } }