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Diffstat (limited to '')
| -rw-r--r-- | debian/patches-rt/0025-serial-dz-Use-port-lock-wrappers.patch | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/debian/patches-rt/0025-serial-dz-Use-port-lock-wrappers.patch b/debian/patches-rt/0025-serial-dz-Use-port-lock-wrappers.patch new file mode 100644 index 000000000..7b3f11604 --- /dev/null +++ b/debian/patches-rt/0025-serial-dz-Use-port-lock-wrappers.patch @@ -0,0 +1,161 @@ +From: Thomas Gleixner <tglx@linutronix.de> +Date: Thu, 14 Sep 2023 20:43:42 +0206 +Subject: [PATCH 025/134] serial: dz: 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/20230914183831.587273-26-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/dz.c | 32 ++++++++++++++++---------------- + 1 file changed, 16 insertions(+), 16 deletions(-) + +--- a/drivers/tty/serial/dz.c ++++ b/drivers/tty/serial/dz.c +@@ -268,9 +268,9 @@ static inline void dz_transmit_chars(str + } + /* If nothing to do or stopped or hardware stopped. */ + if (uart_circ_empty(xmit) || uart_tx_stopped(&dport->port)) { +- spin_lock(&dport->port.lock); ++ uart_port_lock(&dport->port); + dz_stop_tx(&dport->port); +- spin_unlock(&dport->port.lock); ++ uart_port_unlock(&dport->port); + return; + } + +@@ -287,9 +287,9 @@ static inline void dz_transmit_chars(str + + /* Are we are done. */ + if (uart_circ_empty(xmit)) { +- spin_lock(&dport->port.lock); ++ uart_port_lock(&dport->port); + dz_stop_tx(&dport->port); +- spin_unlock(&dport->port.lock); ++ uart_port_unlock(&dport->port); + } + } + +@@ -415,14 +415,14 @@ static int dz_startup(struct uart_port * + return ret; + } + +- spin_lock_irqsave(&dport->port.lock, flags); ++ uart_port_lock_irqsave(&dport->port, &flags); + + /* Enable interrupts. */ + tmp = dz_in(dport, DZ_CSR); + tmp |= DZ_RIE | DZ_TIE; + dz_out(dport, DZ_CSR, tmp); + +- spin_unlock_irqrestore(&dport->port.lock, flags); ++ uart_port_unlock_irqrestore(&dport->port, flags); + + return 0; + } +@@ -443,9 +443,9 @@ static void dz_shutdown(struct uart_port + int irq_guard; + u16 tmp; + +- spin_lock_irqsave(&dport->port.lock, flags); ++ uart_port_lock_irqsave(&dport->port, &flags); + dz_stop_tx(&dport->port); +- spin_unlock_irqrestore(&dport->port.lock, flags); ++ uart_port_unlock_irqrestore(&dport->port, flags); + + irq_guard = atomic_add_return(-1, &mux->irq_guard); + if (!irq_guard) { +@@ -491,14 +491,14 @@ static void dz_break_ctl(struct uart_por + unsigned long flags; + unsigned short tmp, mask = 1 << dport->port.line; + +- spin_lock_irqsave(&uport->lock, flags); ++ uart_port_lock_irqsave(uport, &flags); + tmp = dz_in(dport, DZ_TCR); + if (break_state) + tmp |= mask; + else + tmp &= ~mask; + dz_out(dport, DZ_TCR, tmp); +- spin_unlock_irqrestore(&uport->lock, flags); ++ uart_port_unlock_irqrestore(uport, flags); + } + + static int dz_encode_baud_rate(unsigned int baud) +@@ -608,7 +608,7 @@ static void dz_set_termios(struct uart_p + if (termios->c_cflag & CREAD) + cflag |= DZ_RXENAB; + +- spin_lock_irqsave(&dport->port.lock, flags); ++ uart_port_lock_irqsave(&dport->port, &flags); + + uart_update_timeout(uport, termios->c_cflag, baud); + +@@ -631,7 +631,7 @@ static void dz_set_termios(struct uart_p + if (termios->c_iflag & IGNBRK) + dport->port.ignore_status_mask |= DZ_BREAK; + +- spin_unlock_irqrestore(&dport->port.lock, flags); ++ uart_port_unlock_irqrestore(&dport->port, flags); + } + + /* +@@ -645,12 +645,12 @@ static void dz_pm(struct uart_port *upor + struct dz_port *dport = to_dport(uport); + unsigned long flags; + +- spin_lock_irqsave(&dport->port.lock, flags); ++ uart_port_lock_irqsave(&dport->port, &flags); + if (state < 3) + dz_start_tx(&dport->port); + else + dz_stop_tx(&dport->port); +- spin_unlock_irqrestore(&dport->port.lock, flags); ++ uart_port_unlock_irqrestore(&dport->port, flags); + } + + +@@ -811,7 +811,7 @@ static void dz_console_putchar(struct ua + unsigned short csr, tcr, trdy, mask; + int loops = 10000; + +- spin_lock_irqsave(&dport->port.lock, flags); ++ uart_port_lock_irqsave(&dport->port, &flags); + csr = dz_in(dport, DZ_CSR); + dz_out(dport, DZ_CSR, csr & ~DZ_TIE); + tcr = dz_in(dport, DZ_TCR); +@@ -819,7 +819,7 @@ static void dz_console_putchar(struct ua + mask = tcr; + dz_out(dport, DZ_TCR, mask); + iob(); +- spin_unlock_irqrestore(&dport->port.lock, flags); ++ uart_port_unlock_irqrestore(&dport->port, flags); + + do { + trdy = dz_in(dport, DZ_CSR); |