diff options
Diffstat (limited to 'debian/patches-rt/0067-serial-sunsab-Use-port-lock-wrappers.patch')
| -rw-r--r-- | debian/patches-rt/0067-serial-sunsab-Use-port-lock-wrappers.patch | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/debian/patches-rt/0067-serial-sunsab-Use-port-lock-wrappers.patch b/debian/patches-rt/0067-serial-sunsab-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..b96d5080c --- /dev/null +++ b/debian/patches-rt/0067-serial-sunsab-Use-port-lock-wrappers.patch @@ -0,0 +1,176 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:44:24 +0206 +Subject: [PATCH 067/134] serial: sunsab: Use port lock wrappers +Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/6.6/older/patches-6.6.7-rt18.tar.xz + +When a serial port is used for kernel console output, then all +modifications to the UART registers which are done from other contexts, +e.g. getty, termios, are interference points for the kernel console. + +So far this has been ignored and the printk output is based on the +principle of hope. The rework of the console infrastructure which aims to +support threaded and atomic consoles, requires to mark sections which +modify the UART registers as unsafe. This allows the atomic write function +to make informed decisions and eventually to restore operational state. It +also allows to prevent the regular UART code from modifying UART registers +while printk output is in progress. + +All modifications of UART registers are guarded by the UART port lock, +which provides an obvious synchronization point with the console +infrastructure. + +To avoid adding this functionality to all UART drivers, wrap the +spin_[un]lock*() invocations for uart_port::lock into helper functions +which just contain the spin_[un]lock*() invocations for now. In a +subsequent step these helpers will gain the console synchronization +mechanisms. + +Converted with coccinelle. No functional change. + +Signed-off-by: Thomas Gleixner <tglx@linutronix.de> +Signed-off-by: John Ogness <john.ogness@linutronix.de> +Link: https://lore.kernel.org/r/20230914183831.587273-68-john.ogness@linutronix.de +Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> +Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +--- + drivers/tty/serial/sunsab.c | 34 +++++++++++++++++----------------- + 1 file changed, 17 insertions(+), 17 deletions(-) + +--- a/drivers/tty/serial/sunsab.c ++++ b/drivers/tty/serial/sunsab.c +@@ -310,7 +310,7 @@ static irqreturn_t sunsab_interrupt(int + unsigned long flags; + unsigned char gis; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + status.stat = 0; + gis = readb(&up->regs->r.gis) >> up->gis_shift; +@@ -331,7 +331,7 @@ static irqreturn_t sunsab_interrupt(int + transmit_chars(up, &status); + } + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + if (port) + tty_flip_buffer_push(port); +@@ -473,12 +473,12 @@ static void sunsab_send_xchar(struct uar + if (ch == __DISABLED_CHAR) + return; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + sunsab_tec_wait(up); + writeb(ch, &up->regs->w.tic); + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + /* port->lock held by caller. */ +@@ -499,7 +499,7 @@ static void sunsab_break_ctl(struct uart + unsigned long flags; + unsigned char val; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + val = up->cached_dafo; + if (break_state) +@@ -512,7 +512,7 @@ static void sunsab_break_ctl(struct uart + if (test_bit(SAB82532_XPR, &up->irqflags)) + sunsab_tx_idle(up); + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + /* port->lock is not held. */ +@@ -527,7 +527,7 @@ static int sunsab_startup(struct uart_po + if (err) + return err; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + /* + * Wait for any commands or immediate characters +@@ -582,7 +582,7 @@ static int sunsab_startup(struct uart_po + set_bit(SAB82532_ALLS, &up->irqflags); + set_bit(SAB82532_XPR, &up->irqflags); + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + return 0; + } +@@ -594,7 +594,7 @@ static void sunsab_shutdown(struct uart_ + container_of(port, struct uart_sunsab_port, port); + unsigned long flags; + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + /* Disable Interrupts */ + up->interrupt_mask0 = 0xff; +@@ -628,7 +628,7 @@ static void sunsab_shutdown(struct uart_ + writeb(tmp, &up->regs->rw.ccr0); + #endif + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + free_irq(up->port.irq, up); + } + +@@ -779,9 +779,9 @@ static void sunsab_set_termios(struct ua + unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000); + unsigned int quot = uart_get_divisor(port, baud); + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + sunsab_convert_to_sab(up, termios->c_cflag, termios->c_iflag, baud, quot); +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + static const char *sunsab_type(struct uart_port *port) +@@ -857,15 +857,15 @@ static void sunsab_console_write(struct + int locked = 1; + + if (up->port.sysrq || oops_in_progress) +- locked = spin_trylock_irqsave(&up->port.lock, flags); ++ locked = uart_port_trylock_irqsave(&up->port, &flags); + else +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + uart_console_write(&up->port, s, n, sunsab_console_putchar); + sunsab_tec_wait(up); + + if (locked) +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + } + + static int sunsab_console_setup(struct console *con, char *options) +@@ -914,7 +914,7 @@ static int sunsab_console_setup(struct c + */ + sunsab_startup(&up->port); + +- spin_lock_irqsave(&up->port.lock, flags); ++ uart_port_lock_irqsave(&up->port, &flags); + + /* + * Finally, enable interrupts +@@ -932,7 +932,7 @@ static int sunsab_console_setup(struct c + sunsab_convert_to_sab(up, con->cflag, 0, baud, quot); + sunsab_set_mctrl(&up->port, TIOCM_DTR | TIOCM_RTS); + +- spin_unlock_irqrestore(&up->port.lock, flags); ++ uart_port_unlock_irqrestore(&up->port, flags); + + return 0; + } |