[PATCH 2/4] tty: move baudrate handling code to a file of its own

Nicolas Pitre
2017-04-12T22:38:42Z

To allow reuse without the rest of the tty_ioctl code.
No logical changes from this patch.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
---
drivers/tty/Makefile | 3 +-
drivers/tty/tty_baudrate.c | 232 +++++++++++++++++++++++++++++++++++++++++++++
drivers/tty/tty_ioctl.c | 222 -------------------------------------------
3 files changed, 234 insertions(+), 223 deletions(-)
create mode 100644 drivers/tty/tty_baudrate.c

diff --git a/drivers/tty/Makefile b/drivers/tty/Makefile
index b95bed92da..6983b5a49e 100644
--- a/drivers/tty/Makefile
+++ b/drivers/tty/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_TTY) += tty_io.o n_tty.o tty_ioctl.o tty_ldisc.o \
- tty_buffer.o tty_port.o tty_mutex.o tty_ldsem.o
+ tty_buffer.o tty_port.o tty_mutex.o \
+ tty_ldsem.o tty_baudrate.o
obj-$(CONFIG_LEGACY_PTYS) += pty.o
obj-$(CONFIG_UNIX98_PTYS) += pty.o
obj-$(CONFIG_AUDIT) += tty_audit.o
diff --git a/drivers/tty/tty_baudrate.c b/drivers/tty/tty_baudrate.c
new file mode 100644
index 0000000000..5c33fd2567
--- /dev/null
+++ b/drivers/tty/tty_baudrate.c
@@ -0,0 +1,232 @@
+/*
+ * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/termios.h>
+#include <linux/tty.h>
+#include <linux/export.h>
+
+
+/*
+ * 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.
+ */
+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
+#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
+};
+#endif
+
+static int n_baud_table = ARRAY_SIZE(baud_table);
+
+/**
+ * tty_termios_baud_rate
+ * @termios: termios structure
+ *
+ * Convert termios baud rate data into a speed. This should be called
+ * with the termios lock held if this termios is a terminal termios
+ * structure. May change the termios data. Device drivers can call this
+ * function but should use ->c_[io]speed directly as they are updated.
+ *
+ * Locking: none
+ */
+
+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];
+}
+EXPORT_SYMBOL(tty_termios_baud_rate);
+
+/**
+ * tty_termios_input_baud_rate
+ * @termios: termios structure
+ *
+ * Convert termios baud rate data into a speed. This should be called
+ * with the termios lock held if this termios is a terminal termios
+ * structure. May change the termios data. Device drivers can call this
+ * function but should use ->c_[io]speed directly as they are updated.
+ *
+ * Locking: none
+ */
+
+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);
+
+ /* Magic token for arbitrary speed via c_ispeed*/
+ if (cbaud == BOTHER)
+ return termios->c_ispeed;
+
+ if (cbaud & CBAUDEX) {
+ cbaud &= ~CBAUDEX;
+
+ if (cbaud < 1 || cbaud + 15 > n_baud_table)
+ termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
+ else
+ cbaud += 15;
+ }
+ return baud_table[cbaud];
+#else
+ return tty_termios_baud_rate(termios);
+#endif
+}
+EXPORT_SYMBOL(tty_termios_input_baud_rate);
+
+/**
+ * tty_termios_encode_baud_rate
+ * @termios: ktermios structure holding user requested state
+ * @ispeed: input speed
+ * @ospeed: output speed
+ *
+ * Encode the speeds set into the passed termios structure. This is
+ * used as a library helper for drivers so that they can report back
+ * the actual speed selected when it differs from the speed requested
+ *
+ * For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
+ * we need to carefully set the bits when the user does not get the
+ * desired speed. We allow small margins and preserve as much of possible
+ * of the input intent to keep compatibility.
+ *
+ * Locking: Caller should hold termios lock. This is already held
+ * when calling this function from the driver termios handler.
+ *
+ * The ifdefs deal with platforms whose owners have yet to update them
+ * and will all go away once this is done.
+ */
+
+void tty_termios_encode_baud_rate(struct ktermios *termios,
+ speed_t ibaud, speed_t obaud)
+{
+ int i = 0;
+ int ifound = -1, ofound = -1;
+ int iclose = ibaud/50, oclose = obaud/50;
+ int ibinput = 0;
+
+ if (obaud == 0) /* CD dropped */
+ ibaud = 0; /* Clear ibaud to be sure */
+
+ termios->c_ispeed = ibaud;
+ termios->c_ospeed = obaud;
+
+#ifdef BOTHER
+ /* 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)
+ oclose = 0;
+ if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
+ iclose = 0;
+ if ((termios->c_cflag >> IBSHIFT) & CBAUD)
+ ibinput = 1; /* An input speed was specified */
+#endif
+ termios->c_cflag &= ~CBAUD;
+
+ /*
+ * Our goal is to find a close match to the standard baud rate
+ * returned. Walk the baud rate table and if we get a very close
+ * match then report back the speed as a POSIX Bxxxx value by
+ * preference
+ */
+
+ do {
+ if (obaud - oclose <= baud_table[i] &&
+ obaud + oclose >= baud_table[i]) {
+ termios->c_cflag |= baud_bits[i];
+ ofound = i;
+ }
+ 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);
+ }
+#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
+}
+EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
+
+/**
+ * tty_encode_baud_rate - set baud rate of the tty
+ * @ibaud: input baud rate
+ * @obad: output baud rate
+ *
+ * Update the current termios data for the tty with the new speed
+ * settings. The caller must hold the termios_rwsem for the tty in
+ * question.
+ */
+
+void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
+{
+ tty_termios_encode_baud_rate(&tty->termios, ibaud, obaud);
+}
+EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
diff --git a/drivers/tty/tty_ioctl.c b/drivers/tty/tty_ioctl.c
index a9a978731c..efa96e6c4c 100644
--- a/drivers/tty/tty_ioctl.c
+++ b/drivers/tty/tty_ioctl.c
@@ -258,228 +258,6 @@ static void unset_locked_termios(struct tty_struct *tty, struct ktermios *old)
/* FIXME: What should we do for i/ospeed */
}

-/*
- * 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.
- */
-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
-#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
-};
-#endif
-
-static int n_baud_table = ARRAY_SIZE(baud_table);
-
-/**
- * tty_termios_baud_rate
- * @termios: termios structure
- *
- * Convert termios baud rate data into a speed. This should be called
- * with the termios lock held if this termios is a terminal termios
- * structure. May change the termios data. Device drivers can call this
- * function but should use ->c_[io]speed directly as they are updated.
- *
- * Locking: none
- */
-
-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];
-}
-EXPORT_SYMBOL(tty_termios_baud_rate);
-
-/**
- * tty_termios_input_baud_rate
- * @termios: termios structure
- *
- * Convert termios baud rate data into a speed. This should be called
- * with the termios lock held if this termios is a terminal termios
- * structure. May change the termios data. Device drivers can call this
- * function but should use ->c_[io]speed directly as they are updated.
- *
- * Locking: none
- */
-
-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);
-
- /* Magic token for arbitrary speed via c_ispeed*/
- if (cbaud == BOTHER)
- return termios->c_ispeed;
-
- if (cbaud & CBAUDEX) {
- cbaud &= ~CBAUDEX;
-
- if (cbaud < 1 || cbaud + 15 > n_baud_table)
- termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
- else
- cbaud += 15;
- }
- return baud_table[cbaud];
-#else
- return tty_termios_baud_rate(termios);
-#endif
-}
-EXPORT_SYMBOL(tty_termios_input_baud_rate);
-
-/**
- * tty_termios_encode_baud_rate
- * @termios: ktermios structure holding user requested state
- * @ispeed: input speed
- * @ospeed: output speed
- *
- * Encode the speeds set into the passed termios structure. This is
- * used as a library helper for drivers so that they can report back
- * the actual speed selected when it differs from the speed requested
- *
- * For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
- * we need to carefully set the bits when the user does not get the
- * desired speed. We allow small margins and preserve as much of possible
- * of the input intent to keep compatibility.
- *
- * Locking: Caller should hold termios lock. This is already held
- * when calling this function from the driver termios handler.
- *
- * The ifdefs deal with platforms whose owners have yet to update them
- * and will all go away once this is done.
- */
-
-void tty_termios_encode_baud_rate(struct ktermios *termios,
- speed_t ibaud, speed_t obaud)
-{
- int i = 0;
- int ifound = -1, ofound = -1;
- int iclose = ibaud/50, oclose = obaud/50;
- int ibinput = 0;
-
- if (obaud == 0) /* CD dropped */
- ibaud = 0; /* Clear ibaud to be sure */
-
- termios->c_ispeed = ibaud;
- termios->c_ospeed = obaud;
-
-#ifdef BOTHER
- /* 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)
- oclose = 0;
- if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
- iclose = 0;
- if ((termios->c_cflag >> IBSHIFT) & CBAUD)
- ibinput = 1; /* An input speed was specified */
-#endif
- termios->c_cflag &= ~CBAUD;
-
- /*
- * Our goal is to find a close match to the standard baud rate
- * returned. Walk the baud rate table and if we get a very close
- * match then report back the speed as a POSIX Bxxxx value by
- * preference
- */
-
- do {
- if (obaud - oclose <= baud_table[i] &&
- obaud + oclose >= baud_table[i]) {
- termios->c_cflag |= baud_bits[i];
- ofound = i;
- }
- 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);
- }
-#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
-}
-EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
-
-/**
- * tty_encode_baud_rate - set baud rate of the tty
- * @ibaud: input baud rate
- * @obad: output baud rate
- *
- * Update the current termios data for the tty with the new speed
- * settings. The caller must hold the termios_rwsem for the tty in
- * question.
- */
-
-void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
-{
- tty_termios_encode_baud_rate(&tty->termios, ibaud, obaud);
-}
-EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
-
/**
* tty_termios_copy_hw - copy hardware settings
* @new: New termios
--
2.9.3