From 0f3dcf3b5d76669123bf99fec812b8b0acd60375 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 5 May 2021 11:19:04 +0200 Subject: tty: make fp of tty_ldisc_ops::receive_buf{,2} const Char pointer (cp) passed to tty_ldisc_ops::receive_buf{,2} is const. There is no reason for flag pointer (fp) not to be too. So switch it in the definition and all uses. Signed-off-by: Jiri Slaby Cc: William Hubbs Cc: Chris Brannon Cc: Kirk Reiser Cc: Samuel Thibault Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Cc: Dmitry Torokhov Cc: Arnd Bergmann Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: Andreas Koensgen Cc: Paul Mackerras Cc: Liam Girdwood Cc: Mark Brown Cc: Jaroslav Kysela Cc: Takashi Iwai Cc: Peter Ujfalusi Link: https://lore.kernel.org/r/20210505091928.22010-12-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- drivers/net/caif/caif_serial.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/caif/caif_serial.c') diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c index da6fffb4d5a8..fb3ca4e11fe5 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -159,7 +159,7 @@ static inline void debugfs_tx(struct ser_device *ser, const u8 *data, int size) #endif static void ldisc_receive(struct tty_struct *tty, const u8 *data, - char *flags, int count) + const char *flags, int count) { struct sk_buff *skb = NULL; struct ser_device *ser; -- cgit From 6e94dbc7a4e49a028b81302d755bba1a518f973b Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 5 May 2021 11:19:05 +0200 Subject: tty: cumulate and document tty_struct::flow* members Group the flow flags under a single struct called flow. The new struct contains 'stopped' and 'tco_stopped' bools which used to be bits in a bitfield. The struct also contains the lock protecting them to potentially share the same cache line. Note that commit c545b66c6922b (tty: Serialize tcflow() with other tty flow control changes) added a padding to the original bitfield. It was for the bitfield to occupy a whole 64b word to avoid interferring stores on Alpha (cannot we evaporate this arch with weird implications to C code yet?). But it doesn't work as expected as the padding (tty_struct::unused) is aligned to a 8B boundary too and occupies some bytes from the next word. So make it reliable by: 1) setting __aligned of the struct -- that aligns the start, and 2) making 'unsigned long unused[0]' as the last member of the struct -- pads the end. This is also the perfect time to start the documentation of tty_struct where all this lives. So we start by documenting what these bools actually serve for. And why we do all the alignment dances. Only the few up-to-date information from the Theodore's comment made it into this new Kerneldoc comment. Signed-off-by: Jiri Slaby Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Jonathan Corbet Cc: Arnd Bergmann Cc: Ulf Hansson Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Christian Borntraeger Cc: Shawn Guo Cc: Sascha Hauer Cc: Vineet Gupta Cc: "Maciej W. Rozycki" Link: https://lore.kernel.org/r/20210505091928.22010-13-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- drivers/net/caif/caif_serial.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/net/caif/caif_serial.c') diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c index fb3ca4e11fe5..3996cf7dc9ba 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -87,8 +87,8 @@ static void ldisc_tx_wakeup(struct tty_struct *tty); static inline void update_tty_status(struct ser_device *ser) { ser->tty_status = - ser->tty->stopped << 5 | - ser->tty->flow_stopped << 3 | + ser->tty->flow.stopped << 5 | + ser->tty->flow.tco_stopped << 3 | ser->tty->packet << 2; } static inline void debugfs_init(struct ser_device *ser, struct tty_struct *tty) -- cgit From 64d608db38ffc0c7a25455387096e0aad9410397 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 5 May 2021 11:19:06 +0200 Subject: tty: cumulate and document tty_struct::ctrl* members Group the ctrl members under a single struct called ctrl. The new struct contains 'pgrp', 'session', 'pktstatus', and 'packet'. 'pktstatus' and 'packet' used to be bits in a bitfield. The struct also contains the lock protecting them to share the same cache line. Note that commit c545b66c6922b (tty: Serialize tcflow() with other tty flow control changes) added a padding to the original bitfield. It was for the bitfield to occupy a whole 64b word to avoid interferring stores on Alpha (cannot we evaporate this arch with weird implications to C code yet?). But it doesn't work as expected as the padding (tty_struct::ctrl_unused) is aligned to a 8B boundary too and occupies some bytes from the next word. So make it reliable by: 1) setting __aligned of the struct -- that aligns the start, and 2) making 'unsigned long unused[0]' as the last member of the struct -- pads the end. Add a kerneldoc comment for this grouped members. Signed-off-by: Jiri Slaby Cc: "David S. Miller" Cc: Jakub Kicinski Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20210505091928.22010-14-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- drivers/net/caif/caif_serial.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/caif/caif_serial.c') diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c index 3996cf7dc9ba..b0566588ce33 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -89,7 +89,7 @@ static inline void update_tty_status(struct ser_device *ser) ser->tty_status = ser->tty->flow.stopped << 5 | ser->tty->flow.tco_stopped << 3 | - ser->tty->packet << 2; + ser->tty->ctrl.packet << 2; } static inline void debugfs_init(struct ser_device *ser, struct tty_struct *tty) { -- cgit From fbadf70a8053b3dce78a45997ae55651693a2a81 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 5 May 2021 11:19:07 +0200 Subject: tty: set tty_ldisc_ops::num statically There is no reason to pass the ldisc number to tty_register_ldisc separately. Just set it in the already defined tty_ldisc_ops in all the ldiscs. This simplifies tty_register_ldisc a bit too (no need to set the num member there). Signed-off-by: Jiri Slaby Cc: William Hubbs Cc: Chris Brannon Cc: Kirk Reiser Cc: Samuel Thibault Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Cc: Dmitry Torokhov Cc: Arnd Bergmann Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: Andreas Koensgen Cc: Paul Mackerras Cc: Rodolfo Giometti Cc: Peter Ujfalusi Cc: Liam Girdwood Cc: Mark Brown Cc: Jaroslav Kysela Cc: Takashi Iwai Link: https://lore.kernel.org/r/20210505091928.22010-15-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- drivers/net/caif/caif_serial.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/net/caif/caif_serial.c') diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c index b0566588ce33..2407a0f6656d 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -382,6 +382,7 @@ static void ldisc_close(struct tty_struct *tty) /* The line discipline structure. */ static struct tty_ldisc_ops caif_ldisc = { .owner = THIS_MODULE, + .num = N_CAIF, .name = "n_caif", .open = ldisc_open, .close = ldisc_close, @@ -431,7 +432,7 @@ static int __init caif_ser_init(void) { int ret; - ret = tty_register_ldisc(N_CAIF, &caif_ldisc); + ret = tty_register_ldisc(&caif_ldisc); if (ret < 0) pr_err("cannot register CAIF ldisc=%d err=%d\n", N_CAIF, ret); -- cgit From f81ee8b8b8421dc06d13f197bb53191559cc51da Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Wed, 5 May 2021 11:19:09 +0200 Subject: tty: make tty_ldisc_ops a param in tty_unregister_ldisc Make tty_unregister_ldisc symmetric to tty_register_ldisc by accepting struct tty_ldisc_ops as a parameter instead of ldisc number. This avoids checking of the ldisc number bounds in tty_unregister_ldisc. Signed-off-by: Jiri Slaby Cc: William Hubbs Cc: Chris Brannon Cc: Kirk Reiser Cc: Samuel Thibault Cc: Marcel Holtmann Cc: Johan Hedberg Cc: Luiz Augusto von Dentz Cc: Dmitry Torokhov Cc: Arnd Bergmann Cc: "David S. Miller" Cc: Jakub Kicinski Cc: Wolfgang Grandegger Cc: Marc Kleine-Budde Cc: Andreas Koensgen Cc: Paul Mackerras Cc: Rodolfo Giometti Cc: Peter Ujfalusi Cc: Liam Girdwood Cc: Mark Brown Cc: Jaroslav Kysela Cc: Takashi Iwai Link: https://lore.kernel.org/r/20210505091928.22010-17-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- drivers/net/caif/caif_serial.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/caif/caif_serial.c') diff --git a/drivers/net/caif/caif_serial.c b/drivers/net/caif/caif_serial.c index 2407a0f6656d..d0c24dba4a86 100644 --- a/drivers/net/caif/caif_serial.c +++ b/drivers/net/caif/caif_serial.c @@ -447,7 +447,7 @@ static void __exit caif_ser_exit(void) spin_unlock(&ser_lock); ser_release(NULL); cancel_work_sync(&ser_release_work); - tty_unregister_ldisc(N_CAIF); + tty_unregister_ldisc(&caif_ldisc); debugfs_remove_recursive(debugfsdir); } -- cgit