Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759594AbYBNPQh (ORCPT ); Thu, 14 Feb 2008 10:16:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755853AbYBNPQS (ORCPT ); Thu, 14 Feb 2008 10:16:18 -0500 Received: from mgw1.diku.dk ([130.225.96.91]:57965 "EHLO mgw1.diku.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757254AbYBNPQO (ORCPT ); Thu, 14 Feb 2008 10:16:14 -0500 Date: Thu, 14 Feb 2008 16:16:09 +0100 (MET) From: Julia Lawall To: chas@cmf.nrl.navy.mil, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org Subject: [PATCH 5/6] drivers/atm: Use DIV_ROUND_UP Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4137 Lines: 133 In each case below, I have followed the original semantics, but in drivers/atm/eni.c and drivers/atm/horizon.c, I have some doubts as to whether the original semantics is correct. In drivers/atm/eni.c, is the division intended to be by div or by div-1? In drivers/atm/horizon.c, it seems strange that "case round_down" is implemented by DIV_ROUND_UP, twice. The round_down and default (ie round_up) cases seem to be inversed. --- From: Julia Lawall The kernel.h macro DIV_ROUND_UP performs the computation (((n) + (d) - 1) / (d)) but is perhaps more readable. An extract of the semantic patch that makes this change is as follows: (http://www.emn.fr/x-info/coccinelle/) // @haskernel@ @@ #include @depends on haskernel@ expression n,d; @@ ( - (n + d - 1) / d + DIV_ROUND_UP(n,d) | - (n + (d - 1)) / d + DIV_ROUND_UP(n,d) ) @depends on haskernel@ expression n,d; @@ - DIV_ROUND_UP((n),d) + DIV_ROUND_UP(n,d) @depends on haskernel@ expression n,d; @@ - DIV_ROUND_UP(n,(d)) + DIV_ROUND_UP(n,d) // Signed-off-by: Julia Lawall --- diff -u -p a/drivers/atm/eni.c b/drivers/atm/eni.c --- a/drivers/atm/eni.c 2007-07-20 15:28:28.000000000 +0200 +++ b/drivers/atm/eni.c 2008-02-13 20:50:10.000000000 +0100 @@ -1270,7 +1270,7 @@ static int comp_tx(struct eni_dev *eni_d if (*pre < 3) (*pre)++; /* else fail later */ div = pre_div[*pre]*-*pcr; DPRINTK("max div %d\n",div); - *res = (TS_CLOCK+div-1)/div-1; + *res = DIV_ROUND_UP(TS_CLOCK, div)-1; } if (*res < 0) *res = 0; if (*res > MID_SEG_MAX_RATE) *res = MID_SEG_MAX_RATE; diff -u -p a/drivers/atm/horizon.c b/drivers/atm/horizon.c --- a/drivers/atm/horizon.c 2007-11-08 18:33:26.000000000 +0100 +++ b/drivers/atm/horizon.c 2008-02-13 20:50:13.000000000 +0100 @@ -635,7 +635,7 @@ static int make_rate (const hrz_dev * de // take care of rounding switch (r) { case round_down: - pre = (br+(c<qos.rxtp.max_sdu = 65464; /* fix this - we may want to receive 64kB SDUs later */ - cells = (vcc->qos.rxtp.max_sdu+ATM_AAL5_TRAILER+ - ATM_CELL_PAYLOAD-1)/ATM_CELL_PAYLOAD; + cells = DIV_ROUND_UP(vcc->qos.rxtp.max_sdu+ATM_AAL5_TRAILER, + ATM_CELL_PAYLOAD); zatm_vcc->pool = pool_index(cells*ATM_CELL_PAYLOAD); } else { @@ -820,7 +820,7 @@ static int alloc_shaper(struct atm_dev * } else { i = 255; - m = (ATM_OC3_PCR*255+max-1)/max; + m = DIV_ROUND_UP(ATM_OC3_PCR*255, max); } } if (i > m) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/