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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 0A8E3C64EB8 for ; Sun, 7 Oct 2018 03:38:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B4E8520841 for ; Sun, 7 Oct 2018 03:38:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B4E8520841 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727771AbeJGKoc (ORCPT ); Sun, 7 Oct 2018 06:44:32 -0400 Received: from terminus.zytor.com ([198.137.202.136]:52689 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbeJGKoc (ORCPT ); Sun, 7 Oct 2018 06:44:32 -0400 Received: from carbon-x1.hos.anvin.org (c-24-5-245-234.hsd1.ca.comcast.net [24.5.245.234] (may be forged)) (authenticated bits=0) by mail.zytor.com (8.15.2/8.15.2) with ESMTPSA id w973btxq047551 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sat, 6 Oct 2018 20:37:56 -0700 Received: from carbon-x1.hos.anvin.org (localhost [127.0.0.1]) by carbon-x1.hos.anvin.org (8.15.2/8.15.2) with ESMTP id w973bouu224518; Sat, 6 Oct 2018 20:37:50 -0700 Received: (from hpa@localhost) by carbon-x1.hos.anvin.org (8.15.2/8.15.2/Submit) id w973boje224517; Sat, 6 Oct 2018 20:37:50 -0700 From: "H. Peter Anvin" To: linux-kernel@vger.kernel.org Cc: "H. Peter Anvin (Intel)" , Greg Kroah-Hartman , Jiri Slaby , Al Viro , Richard Henderson , Ivan Kokshaysky , Matt Turner , Thomas Gleixner , Kate Stewart , Philippe Ombredanne , Eugene Syromiatnikov , linux-alpha@vger.kernel.org, linux-serial@vger.kernel.org, Johan Hovold , Alan Cox , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , stable@vger.kernel.org Subject: [PATCH stable 2/2] termios, tty/tty_baudrate.c: simplify, auto-generate baud table Date: Sat, 6 Oct 2018 20:37:48 -0700 Message-Id: <20181007033748.224461-3-hpa@zytor.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181007033748.224461-1-hpa@zytor.com> References: <20181007033748.224461-1-hpa@zytor.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "H. Peter Anvin (Intel)" Now when all architectures define BOTHER and IBSHIFT, we can unconditionally rely on these constants. Furthermore, the code can be significantly simplified in a number of places. Finally, rather than having two tables and needing to be able to keep them in sync at all times, have one auto-generated table. This also lets us avoid the fact that architectures that have CBAUDEX == 0 have BOTHER in a different location that those that don't. Finally, this patch avoids overrunning the baud_table[] for architectures with CBAUDEX == 0 (Alpha and PowerPC). Signed-off-by: H. Peter Anvin (Intel) Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Al Viro Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Thomas Gleixner Cc: Kate Stewart Cc: Philippe Ombredanne Cc: Greg Kroah-Hartman Cc: Eugene Syromiatnikov Cc: Cc: Cc: Johan Hovold Cc: Alan Cox Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: --- drivers/tty/.gitignore | 1 + drivers/tty/Makefile | 16 ++++ drivers/tty/bmacros.c | 2 + drivers/tty/tty_baudrate.c | 190 +++++++++++++++---------------------- 4 files changed, 93 insertions(+), 116 deletions(-) create mode 100644 drivers/tty/.gitignore create mode 100644 drivers/tty/bmacros.c diff --git a/drivers/tty/.gitignore b/drivers/tty/.gitignore new file mode 100644 index 000000000000..d436c18a912c --- /dev/null +++ b/drivers/tty/.gitignore @@ -0,0 +1 @@ +bmacros.h diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile index c72cafdf32b4..489b222ab1ce 100644 --- a/drivers/tty/Makefile +++ b/drivers/tty/Makefile @@ -35,3 +35,19 @@ obj-$(CONFIG_MIPS_EJTAG_FDC_TTY) += mips_ejtag_fdc.o obj-$(CONFIG_VCC) += vcc.o obj-y += ipwireless/ + +# +# Rules for generating the baud rate table +# +CFLAGS_bmacros.o += -Wp,-dM + +$(obj)/tty_baudrate.o: $(obj)/bmacros.h + +quiet_cmd_bmacros = BMACROS $@ + cmd_bmacros = ( \ + sed -nr -e 's/^.define B([0-9]+) .*$$/BTBL(B\1,\1)/p' $< \ + | sort -n -k1.7 > $@ ) || (rm -f $@ ; echo false) + +targets += bmacros.h +$(obj)/bmacros.h: $(obj)/bmacros.i FORCE + $(call if_changed,bmacros) diff --git a/drivers/tty/bmacros.c b/drivers/tty/bmacros.c new file mode 100644 index 000000000000..0af865ff00de --- /dev/null +++ b/drivers/tty/bmacros.c @@ -0,0 +1,2 @@ +/* This file is used to extract the B... macros from header files */ +#include diff --git a/drivers/tty/tty_baudrate.c b/drivers/tty/tty_baudrate.c index 7576ceace571..5a41eda7912a 100644 --- a/drivers/tty/tty_baudrate.c +++ b/drivers/tty/tty_baudrate.c @@ -9,43 +9,56 @@ #include #include - /* - * Routine which returns the baud rate of the tty - * - * Note that the baud_table needs to be kept in sync with the - * include/asm/termbits.h file. + * Routine which returns the baud rate of the tty. The B... constants + * are extracted from the appropriate header files via + * bmacros.c -> bmacros.h. */ -static const speed_t baud_table[] = { - 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, - 9600, 19200, 38400, 57600, 115200, 230400, 460800, -#ifdef __sparc__ - 76800, 153600, 307200, 614400, 921600 -#else - 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000, - 2500000, 3000000, 3500000, 4000000 + +/* CBAUD mask with CBAUDEX removed */ +#define CBAUDNX (CBAUD & ~CBAUDEX) + +/* Lowest bit in CBAUDEX, if any. CBAUDEX is assumed contiguous. */ +#define CBAUDEL (CBAUDEX & ~(CBAUDEX << 1)) +#if CBAUDEL & (CBAUDEL-1) +# error "CBAUDEX is not contiguous" #endif -}; -#ifndef __sparc__ -static const tcflag_t baud_bits[] = { - B0, B50, B75, B110, B134, B150, B200, B300, B600, - B1200, B1800, B2400, B4800, B9600, B19200, B38400, - B57600, B115200, B230400, B460800, B500000, B576000, - B921600, B1000000, B1152000, B1500000, B2000000, B2500000, - B3000000, B3500000, B4000000 -}; -#else -static const tcflag_t baud_bits[] = { - B0, B50, B75, B110, B134, B150, B200, B300, B600, - B1200, B1800, B2400, B4800, B9600, B19200, B38400, - B57600, B115200, B230400, B460800, B76800, B153600, - B307200, B614400, B921600 +/* Convert from B... constant to table position */ +#define BPOS(x) (((x) & CBAUDNX) + \ + (CBAUDEX ? ((x) & CBAUDEX)/CBAUDEL*(CBAUDNX+1) : 0)) + +/* Convert from table position to B... constant */ +#define BVAL(x) (((x) & CBAUDNX) + (((x)/(CBAUDNX+1)*CBAUDEX) & CBAUDEX)) + +/* Entry into the baud_table */ +#define BTBL(b,v) [BPOS(b)] = (v), + +static const speed_t baud_table[] = { +#include "bmacros.h" }; -#endif static int n_baud_table = ARRAY_SIZE(baud_table); +/* Helper function; will be called with cbaud already masked */ +static speed_t _tty_termios_baud_rate(unsigned int cbaud, speed_t bother_speed) +{ + /* Magic token for arbitrary speed via c_ispeed/c_ospeed */ + if (cbaud == BOTHER) + return bother_speed; + + cbaud = BPOS(cbaud); + + /* If CBAUDEX != 0, and we overrun the table, try dropping CBAUDEX */ + if (cbaud & ~CBAUDNX) { + if (BPOS(cbaud) >= n_baud_table) { + /* Try without CBAUDEX */ + cbaud &= ~CBAUDNX; + } + } + return (cbaud >= n_baud_table) ? 0 : baud_table[cbaud]; +} + /** * tty_termios_baud_rate * @termios: termios structure @@ -60,24 +73,8 @@ static int n_baud_table = ARRAY_SIZE(baud_table); speed_t tty_termios_baud_rate(struct ktermios *termios) { - unsigned int cbaud; - - cbaud = termios->c_cflag & CBAUD; - -#ifdef BOTHER - /* Magic token for arbitrary speed via c_ispeed/c_ospeed */ - if (cbaud == BOTHER) - return termios->c_ospeed; -#endif - if (cbaud & CBAUDEX) { - cbaud &= ~CBAUDEX; - - if (cbaud < 1 || cbaud + 15 > n_baud_table) - termios->c_cflag &= ~CBAUDEX; - else - cbaud += 15; - } - return baud_table[cbaud]; + return _tty_termios_baud_rate(termios->c_cflag & CBAUD, + termios->c_ospeed); } EXPORT_SYMBOL(tty_termios_baud_rate); @@ -95,28 +92,15 @@ EXPORT_SYMBOL(tty_termios_baud_rate); speed_t tty_termios_input_baud_rate(struct ktermios *termios) { -#ifdef IBSHIFT - unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD; - - if (cbaud == B0) - return tty_termios_baud_rate(termios); -#ifdef BOTHER - /* Magic token for arbitrary speed via c_ispeed*/ - if (cbaud == BOTHER) - return termios->c_ispeed; -#endif - if (cbaud & CBAUDEX) { - cbaud &= ~CBAUDEX; + unsigned int cbaud; + speed_t bother_speed = termios->c_ispeed; - if (cbaud < 1 || cbaud + 15 > n_baud_table) - termios->c_cflag &= ~(CBAUDEX << IBSHIFT); - else - cbaud += 15; + cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD; + if (cbaud == B0) { + cbaud = termios->c_cflag & CBAUD; + bother_speed = termios->c_ospeed; } - return baud_table[cbaud]; -#else /* IBSHIFT */ - return tty_termios_baud_rate(termios); -#endif /* IBSHIFT */ + return _tty_termios_baud_rate(cbaud, bother_speed); } EXPORT_SYMBOL(tty_termios_input_baud_rate); @@ -145,38 +129,27 @@ EXPORT_SYMBOL(tty_termios_input_baud_rate); void tty_termios_encode_baud_rate(struct ktermios *termios, speed_t ibaud, speed_t obaud) { - int i = 0; - int ifound = -1, ofound = -1; + int i; + unsigned int ifound, ofound; int iclose = ibaud/50, oclose = obaud/50; - int ibinput = 0; + bool ibinput = false; - if (obaud == 0) /* CD dropped */ + if (obaud == 0) /* CD dropped */ ibaud = 0; /* Clear ibaud to be sure */ termios->c_ispeed = ibaud; termios->c_ospeed = obaud; -#ifdef IBSHIFT - if ((termios->c_cflag >> IBSHIFT) & CBAUD) - ibinput = 1; /* An input speed was specified */ -#endif -#ifdef BOTHER + ibinput = ((termios->c_cflag >> IBSHIFT) & CBAUD) != B0; + /* If the user asked for a precise weird speed give a precise weird answer. If they asked for a Bfoo speed they may have problems digesting non-exact replies so fuzz a bit */ - if ((termios->c_cflag & CBAUD) == BOTHER) { + if ((termios->c_cflag & CBAUD) == BOTHER) oclose = 0; - if (!ibinput) - iclose = 0; - } if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER) iclose = 0; -#endif - termios->c_cflag &= ~CBAUD; -#ifdef IBSHIFT - termios->c_cflag &= ~(CBAUD << IBSHIFT); -#endif /* * Our goal is to find a close match to the standard baud rate @@ -184,43 +157,28 @@ void tty_termios_encode_baud_rate(struct ktermios *termios, * match then report back the speed as a POSIX Bxxxx value by * preference */ - - do { + ofound = ifound = BOTHER; + for (i = 0; i < n_baud_table; i++) { if (obaud - oclose <= baud_table[i] && obaud + oclose >= baud_table[i]) { - termios->c_cflag |= baud_bits[i]; - ofound = i; + ofound = BVAL(i); + break; } - if (ibaud - iclose <= baud_table[i] && - ibaud + iclose >= baud_table[i]) { - /* For the case input == output don't set IBAUD bits - if the user didn't do so */ - if (ofound == i && !ibinput) - ifound = i; -#ifdef IBSHIFT - else { - ifound = i; - termios->c_cflag |= (baud_bits[i] << IBSHIFT); + } + if (!ibinput) { + ifound = 0; + } else { + for (i = 0; i < n_baud_table; i++) { + if (ibaud - iclose <= baud_table[i] && + ibaud + iclose >= baud_table[i]) { + ifound = BVAL(i); + break; } -#endif } - } while (++i < n_baud_table); + } - /* - * If we found no match then use BOTHER if provided or warn - * the user their platform maintainer needs to wake up if not. - */ -#ifdef BOTHER - if (ofound == -1) - termios->c_cflag |= BOTHER; - /* Set exact input bits only if the input and output differ or the - user already did */ - if (ifound == -1 && (ibaud != obaud || ibinput)) - termios->c_cflag |= (BOTHER << IBSHIFT); -#else - if (ifound == -1 || ofound == -1) - pr_warn_once("tty: Unable to return correct speed data as your architecture needs updating.\n"); -#endif + termios->c_cflag &= ~(CBAUD | (CBAUD << IBSHIFT)); + termios->c_cflag |= ofound | (ifound << IBSHIFT); } EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate); -- 2.17.1