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.
Provide and use wrapper functions for spin_[un]lock*(port->lock)
invocations so that the console mechanics can be applied later on at a
single place and does not require to copy the same logic all over the
drivers.
Patch 1 adds the wrapper functions.
Patches 2-74 switch all uart port locking call sites to use the new
wrappers. These patches were automatically generated using coccinelle.
The 2 used coccinelle scripts are included below and executed as
follows:
$ spatch --sp-file uartlock-1.cocci $FILE
$ spatch --sp-file uartlock-2.cocci --recursive-includes $FILE
This series brings no functional change.
Patches 2-74 contain identical commit message bodies. Feel free to
fold them into a single commit if that seems more reasonable.
Thomas Gleixner (74):
serial: core: Provide port lock wrappers
serial: core: Use lock wrappers
serial: 21285: Use port lock wrappers
serial: 8250_aspeed_vuart: Use port lock wrappers
serial: 8250_bcm7271: Use port lock wrappers
serial: 8250: Use port lock wrappers
serial: 8250_dma: Use port lock wrappers
serial: 8250_dw: Use port lock wrappers
serial: 8250_exar: Use port lock wrappers
serial: 8250_fsl: Use port lock wrappers
serial: 8250_mtk: Use port lock wrappers
serial: 8250_omap: Use port lock wrappers
serial: 8250_pci1xxxx: Use port lock wrappers
serial: altera_jtaguart: Use port lock wrappers
serial: altera_uart: Use port lock wrappers
serial: amba-pl010: Use port lock wrappers
serial: amba-pl011: Use port lock wrappers
serial: apb: Use port lock wrappers
serial: ar933x: Use port lock wrappers
serial: arc_uart: Use port lock wrappers
serial: atmel: Use port lock wrappers
serial: bcm63xx-uart: Use port lock wrappers
serial: cpm_uart: Use port lock wrappers
serial: digicolor: Use port lock wrappers
serial: dz: Use port lock wrappers
serial: linflexuart: Use port lock wrappers
serial: fsl_lpuart: Use port lock wrappers
serial: icom: Use port lock wrappers
serial: imx: Use port lock wrappers
serial: ip22zilog: Use port lock wrappers
serial: jsm: Use port lock wrappers
serial: liteuart: Use port lock wrappers
serial: lpc32xx_hs: Use port lock wrappers
serial: ma35d1: Use port lock wrappers
serial: mcf: Use port lock wrappers
serial: men_z135_uart: Use port lock wrappers
serial: meson: Use port lock wrappers
serial: milbeaut_usio: Use port lock wrappers
serial: mpc52xx: Use port lock wrappers
serial: mps2-uart: Use port lock wrappers
serial: msm: Use port lock wrappers
serial: mvebu-uart: Use port lock wrappers
serial: omap: Use port lock wrappers
serial: owl: Use port lock wrappers
serial: pch: Use port lock wrappers
serial: pic32: Use port lock wrappers
serial: pmac_zilog: Use port lock wrappers
serial: pxa: Use port lock wrappers
serial: qcom-geni: Use port lock wrappers
serial: rda: Use port lock wrappers
serial: rp2: Use port lock wrappers
serial: sa1100: Use port lock wrappers
serial: samsung_tty: Use port lock wrappers
serial: sb1250-duart: Use port lock wrappers
serial: sc16is7xx: Use port lock wrappers
serial: tegra: Use port lock wrappers
serial: core: Use port lock wrappers
serial: mctrl_gpio: Use port lock wrappers
serial: txx9: Use port lock wrappers
serial: sh-sci: Use port lock wrappers
serial: sifive: Use port lock wrappers
serial: sprd: Use port lock wrappers
serial: st-asc: Use port lock wrappers
serial: stm32: Use port lock wrappers
serial: sunhv: Use port lock wrappers
serial: sunplus-uart: Use port lock wrappers
serial: sunsab: Use port lock wrappers
serial: sunsu: Use port lock wrappers
serial: sunzilog: Use port lock wrappers
serial: timbuart: Use port lock wrappers
serial: uartlite: Use port lock wrappers
serial: ucc_uart: Use port lock wrappers
serial: vt8500: Use port lock wrappers
serial: xilinx_uartps: Use port lock wrappers
drivers/tty/serial/21285.c | 8 +-
drivers/tty/serial/8250/8250_aspeed_vuart.c | 6 +-
drivers/tty/serial/8250/8250_bcm7271.c | 28 +++---
drivers/tty/serial/8250/8250_core.c | 12 +--
drivers/tty/serial/8250/8250_dma.c | 8 +-
drivers/tty/serial/8250/8250_dw.c | 8 +-
drivers/tty/serial/8250/8250_exar.c | 4 +-
drivers/tty/serial/8250/8250_fsl.c | 6 +-
drivers/tty/serial/8250/8250_mtk.c | 8 +-
drivers/tty/serial/8250/8250_omap.c | 52 +++++-----
drivers/tty/serial/8250/8250_pci1xxxx.c | 8 +-
drivers/tty/serial/8250/8250_port.c | 100 ++++++++++----------
drivers/tty/serial/altera_jtaguart.c | 28 +++---
drivers/tty/serial/altera_uart.c | 20 ++--
drivers/tty/serial/amba-pl010.c | 20 ++--
drivers/tty/serial/amba-pl011.c | 72 +++++++-------
drivers/tty/serial/apbuart.c | 8 +-
drivers/tty/serial/ar933x_uart.c | 26 ++---
drivers/tty/serial/arc_uart.c | 16 ++--
drivers/tty/serial/atmel_serial.c | 24 ++---
drivers/tty/serial/bcm63xx_uart.c | 22 ++---
drivers/tty/serial/cpm_uart.c | 8 +-
drivers/tty/serial/digicolor-usart.c | 18 ++--
drivers/tty/serial/dz.c | 32 +++----
drivers/tty/serial/fsl_linflexuart.c | 26 ++---
drivers/tty/serial/fsl_lpuart.c | 88 ++++++++---------
drivers/tty/serial/icom.c | 26 ++---
drivers/tty/serial/imx.c | 84 ++++++++--------
drivers/tty/serial/ip22zilog.c | 36 +++----
drivers/tty/serial/jsm/jsm_neo.c | 4 +-
drivers/tty/serial/jsm/jsm_tty.c | 16 ++--
drivers/tty/serial/liteuart.c | 20 ++--
drivers/tty/serial/lpc32xx_hs.c | 26 ++---
drivers/tty/serial/ma35d1_serial.c | 22 ++---
drivers/tty/serial/mcf.c | 20 ++--
drivers/tty/serial/men_z135_uart.c | 8 +-
drivers/tty/serial/meson_uart.c | 30 +++---
drivers/tty/serial/milbeaut_usio.c | 16 ++--
drivers/tty/serial/mpc52xx_uart.c | 12 +--
drivers/tty/serial/mps2-uart.c | 16 ++--
drivers/tty/serial/msm_serial.c | 38 ++++----
drivers/tty/serial/mvebu-uart.c | 18 ++--
drivers/tty/serial/omap-serial.c | 38 ++++----
drivers/tty/serial/owl-uart.c | 26 ++---
drivers/tty/serial/pch_uart.c | 10 +-
drivers/tty/serial/pic32_uart.c | 20 ++--
drivers/tty/serial/pmac_zilog.c | 52 +++++-----
drivers/tty/serial/pxa.c | 30 +++---
drivers/tty/serial/qcom_geni_serial.c | 8 +-
drivers/tty/serial/rda-uart.c | 34 +++----
drivers/tty/serial/rp2.c | 20 ++--
drivers/tty/serial/sa1100.c | 20 ++--
drivers/tty/serial/samsung_tty.c | 50 +++++-----
drivers/tty/serial/sb1250-duart.c | 12 +--
drivers/tty/serial/sc16is7xx.c | 40 ++++----
drivers/tty/serial/serial-tegra.c | 32 +++----
drivers/tty/serial/serial_core.c | 88 ++++++++---------
drivers/tty/serial/serial_mctrl_gpio.c | 4 +-
drivers/tty/serial/serial_port.c | 4 +-
drivers/tty/serial/serial_txx9.c | 26 ++---
drivers/tty/serial/sh-sci.c | 68 ++++++-------
drivers/tty/serial/sifive.c | 16 ++--
drivers/tty/serial/sprd_serial.c | 30 +++---
drivers/tty/serial/st-asc.c | 18 ++--
drivers/tty/serial/stm32-usart.c | 38 ++++----
drivers/tty/serial/sunhv.c | 28 +++---
drivers/tty/serial/sunplus-uart.c | 26 ++---
drivers/tty/serial/sunsab.c | 34 +++----
drivers/tty/serial/sunsu.c | 46 ++++-----
drivers/tty/serial/sunzilog.c | 42 ++++----
drivers/tty/serial/timbuart.c | 8 +-
drivers/tty/serial/uartlite.c | 18 ++--
drivers/tty/serial/ucc_uart.c | 4 +-
drivers/tty/serial/vt8500_serial.c | 8 +-
drivers/tty/serial/xilinx_uartps.c | 56 +++++------
include/linux/serial_core.h | 91 ++++++++++++++++--
76 files changed, 1086 insertions(+), 1007 deletions(-)
base-commit: 0bb80ecc33a8fb5a682236443c1e740d5c917d1d
--
2.39.2
--------------8<--------------
// uartlock-1.cocci
@r1@
struct uart_port *U;
@@
-spin_lock(&U->lock)
+uart_port_lock(U)
@r2@
struct uart_port *U;
@@
-spin_lock_irq(&U->lock)
+uart_port_lock_irq(U)
@r3@
struct uart_port *U;
identifier F;
@@
-spin_lock_irqsave(&U->lock, F)
+uart_port_lock_irqsave(U, &F)
@r4@
struct uart_port *U;
@@
-spin_unlock(&U->lock)
+uart_port_unlock(U)
@r5@
struct uart_port *U;
@@
-spin_unlock_irq(&U->lock)
+uart_port_unlock_irq(U)
@r6@
struct uart_port *U;
identifier F;
@@
-spin_unlock_irqrestore(&U->lock, F)
+uart_port_unlock_irqrestore(U, F)
@r7@
struct uart_port *U;
@@
-spin_trylock(&U->lock)
+uart_port_trylock(U)
@r8@
struct uart_port *U;
identifier F;
@@
-spin_trylock_irqsave(&U->lock, F)
+uart_port_trylock_irqsave(U, &F)
--------------8<--------------
// uartlock-2.cocci
@r10@
type T1;
identifier U;
@@
T1 {
...
struct uart_port U;
...
};
@r11@
r10.T1 *E;
identifier r10.U;
@@
-spin_lock(&E->U.lock)
+uart_port_lock(&E->U)
@r12@
r10.T1 *E;
identifier r10.U;
@@
-spin_lock_irq(&E->U.lock)
+uart_port_lock_irq(&E->U)
@r13@
r10.T1 *E;
identifier r10.U;
identifier F;
@@
-spin_lock_irqsave(&E->U.lock, F)
+uart_port_lock_irqsave(&E->U, &F)
@r14@
r10.T1 *E;
identifier r10.U;
@@
-spin_unlock(&E->U.lock)
+uart_port_unlock(&E->U)
@r15@
r10.T1 *E;
identifier r10.U;
@@
-spin_unlock_irq(&E->U.lock)
+uart_port_unlock_irq(&E->U)
@r16@
r10.T1 *E;
identifier r10.U;
identifier F;
@@
-spin_unlock_irqrestore(&E->U.lock, F)
+uart_port_unlock_irqrestore(&E->U, F)
@r17@
r10.T1 *E;
identifier r10.U;
@@
-spin_trylock(&E->U.lock)
+uart_port_trylock(&E->U)
@r18@
r10.T1 *E;
identifier r10.U;
identifier F;
@@
-spin_trylock_irqsave(&E->U.lock, F)
+uart_port_trylock_irqsave(&E->U, &F)
