commit 2f83e38a09 upstream.
With this, processes without CAP_SYS_ADMIN are able to use TIOCLINUX with
subcode TIOCL_SETSEL, in the selection modes TIOCL_SETPOINTER,
TIOCL_SELCLEAR and TIOCL_SELMOUSEREPORT.
TIOCL_SETSEL was previously changed to require CAP_SYS_ADMIN, as this IOCTL
let callers change the selection buffer and could be used to simulate
keypresses. These three TIOCL_SETSEL selection modes, however, are safe to
use, as they do not modify the selection buffer.
This fixes a mouse support regression that affected Emacs (invisible mouse
cursor).
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/ee3ec63269b43b34e1c90dd8c9743bf8@finder.org
Fixes: 8d1b43f6a6 ("tty: Restrict access to TIOCLINUX' copy-and-paste subcommands")
Signed-off-by: Günther Noack <gnoack@google.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Link: https://lore.kernel.org/r/20250110142122.1013222-1-gnoack@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b06f388994 upstream.
lockdep detects the following circular locking dependency:
CPU 0 CPU 1
========================== ============================
cdns_uart_isr() printk()
uart_port_lock(port) console_lock()
cdns_uart_console_write()
if (!port->sysrq)
uart_port_lock(port)
uart_handle_break()
port->sysrq = ...
uart_handle_sysrq_char()
printk()
console_lock()
The fixed commit attempts to avoid this situation by only taking the
port lock in cdns_uart_console_write if port->sysrq unset. However, if
(as shown above) cdns_uart_console_write runs before port->sysrq is set,
then it will try to take the port lock anyway. This may result in a
deadlock.
Fix this by splitting sysrq handling into two parts. We use the prepare
helper under the port lock and defer handling until we release the lock.
Fixes: 74ea66d4ca ("tty: xuartps: Improve sysrq handling")
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Cc: stable@vger.kernel.org # c980248179: serial: xilinx_uartps: Use port lock wrappers
Acked-by: John Ogness <john.ogness@linutronix.de>
Link: https://lore.kernel.org/r/20250110213822.2107462-1-sean.anderson@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d91f98be26 ]
After a console has written a record into UART_TX, it uses
wait_for_xmitr() to wait until the data has been sent out before
returning. However, wait_for_xmitr() will timeout after 10ms,
regardless if the data has been transmitted or not.
For single bytes, this timeout is sufficient even at very slow
baud rates, such as 1200bps. However, when FIFO mode is used,
there may be 64 bytes pushed into the FIFO at once. At a baud
rate of 115200bps, the 10ms timeout is still sufficient. But
when using lower baud rates (such as 57600bps), the timeout
is _not_ sufficient. This causes longer lines to be cut off,
resulting in lost and horribly misformatted output on the
console.
When using FIFO mode, take the number of bytes into account to
determine an appropriate maximum timeout. Increasing the timeout
does not affect performance since ideally the timeout never
occurs.
Fixes: 8f3631f0f6 ("serial/8250: Use fifo in 8250 console driver")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Wander Lairson Costa <wander@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20250107212702.169493-2-john.ogness@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ceb8bf2cea ]
Commit cdd30ebb1b ("module: Convert symbol namespace to string
literal") only converted MODULE_IMPORT_NS() and EXPORT_SYMBOL_NS(),
leaving DEFAULT_SYMBOL_NAMESPACE as a macro expansion.
This commit converts DEFAULT_SYMBOL_NAMESPACE in the same way to avoid
annoyance for the default namespace as well.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Stable-dep-of: 2505f87eb3 ("hwmon: (nct6775): Actually make use of the HWMON_NCT6775 symbol namespace")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit ed2761958a upstream.
The commit f9b11229b7 ("serial: 8250: Fix PM usage_count for console
handover") fixed one runtime PM usage counter balance problem that
occurs because .dev is not set during univ8250 setup preventing call to
pm_runtime_get_sync(). Later, univ8250_console_exit() will trigger the
runtime PM usage counter underflow as .dev is already set at that time.
Call pm_runtime_get_sync() to balance the RPM usage counter also in
serial8250_register_8250_port() before trying to add the port.
Reported-by: Borislav Petkov (AMD) <bp@alien8.de>
Fixes: bedb404e91 ("serial: 8250_port: Don't use power management for kernel console")
Cc: stable <stable@kernel.org>
Tested-by: Borislav Petkov (AMD) <bp@alien8.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20241210170120.2231-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7cc0e0a43a upstream.
On the Renesas RZ/G3S, when doing suspend to RAM, the uart_suspend_port()
is called. The uart_suspend_port() calls 3 times the
struct uart_port::ops::tx_empty() before shutting down the port.
According to the documentation, the struct uart_port::ops::tx_empty()
API tests whether the transmitter FIFO and shifter for the port is
empty.
The Renesas RZ/G3S SCIFA IP reports the number of data units stored in the
transmit FIFO through the FDR (FIFO Data Count Register). The data units
in the FIFOs are written in the shift register and transmitted from there.
The TEND bit in the Serial Status Register reports if the data was
transmitted from the shift register.
In the previous code, in the tx_empty() API implemented by the sh-sci
driver, it is considered that the TX is empty if the hardware reports the
TEND bit set and the number of data units in the FIFO is zero.
According to the HW manual, the TEND bit has the following meaning:
0: Transmission is in the waiting state or in progress.
1: Transmission is completed.
It has been noticed that when opening the serial device w/o using it and
then switch to a power saving mode, the tx_empty() call in the
uart_port_suspend() function fails, leading to the "Unable to drain
transmitter" message being printed on the console. This is because the
TEND=0 if nothing has been transmitted and the FIFOs are empty. As the
TEND=0 has double meaning (waiting state, in progress) we can't
determined the scenario described above.
Add a software workaround for this. This sets a variable if any data has
been sent on the serial console (when using PIO) or if the DMA callback has
been called (meaning something has been transmitted). In the tx_empty()
API the status of the DMA transaction is also checked and if it is
completed or in progress the code falls back in checking the hardware
registers instead of relying on the software variable.
Fixes: 73a19e4c03 ("serial: sh-sci: Add DMA support.")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20241125115856.513642-1-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b5a23a60e8 upstream.
When CONFIG_DMA_ENGINE is disabled, the driver now fails to build:
drivers/tty/serial/amba-pl011.c: In function 'pl011_unthrottle_rx':
drivers/tty/serial/amba-pl011.c:1822:16: error: 'struct uart_amba_port' has no member named 'using_rx_dma'
1822 | if (uap->using_rx_dma) {
| ^~
drivers/tty/serial/amba-pl011.c:1823:20: error: 'struct uart_amba_port' has no member named 'dmacr'
1823 | uap->dmacr |= UART011_RXDMAE;
| ^~
drivers/tty/serial/amba-pl011.c:1824:32: error: 'struct uart_amba_port' has no member named 'dmacr'
1824 | pl011_write(uap->dmacr, uap, REG_DMACR);
| ^~
Add the missing #ifdef check around these field accesses, matching
what other parts of this driver do.
Fixes: 2bcacc1c87 ("serial: amba-pl011: Fix RX stall when DMA is used")
Cc: stable <stable@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202411140617.nkjeHhsK-lkp@intel.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20241115110021.744332-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 2bcacc1c87 upstream.
Function pl011_throttle_rx() calls pl011_stop_rx() to disable RX, which
also disables the RX DMA by clearing the RXDMAE bit of the DMACR
register. However, to properly unthrottle RX when DMA is used, the
function pl011_unthrottle_rx() is expected to set the RXDMAE bit of
the DMACR register, which it currently lacks. This causes RX to stall
after the throttle API is called.
Set RXDMAE bit in the DMACR register while unthrottling RX if RX DMA is
used.
Fixes: 211565b100 ("serial: pl011: UPSTAT_AUTORTS requires .throttle/unthrottle")
Cc: stable@vger.kernel.org
Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20241113092629.60226-1-kkartik@nvidia.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit bcc7ba6688 upstream.
Currently in omap_8250_shutdown, the dma->rx_running flag is
set to zero in omap_8250_rx_dma_flush. Next pm_runtime_get_sync
is called, which is a runtime resume call stack which can
re-set the flag. When the call omap_8250_shutdown returns, the
flag is expected to be UN-SET, but this is not the case. This
is causing issues the next time UART is re-opened and
omap_8250_rx_dma is called. Fix by moving pm_runtime_get_sync
before the omap_8250_rx_dma_flush.
cc: stable@vger.kernel.org
Fixes: 0e31c8d173 ("tty: serial: 8250_omap: add custom DMA-RX callback")
Signed-off-by: Bin Liu <b-liu@ti.com>
[Judith: Add commit message]
Signed-off-by: Judith Mendez <jm@ti.com>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20241031172315.453750-1-jm@ti.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3791ea69a4 upstream.
The early_console_setup() function initializes the sci_ports[0].port with
an object of type struct uart_port obtained from the object of type
struct earlycon_device received as argument by the early_console_setup().
It may happen that later, when the rest of the serial ports are probed,
the serial port that was used as earlycon (e.g., port A) to be mapped to a
different position in sci_ports[] and the slot 0 to be used by a different
serial port (e.g., port B), as follows:
sci_ports[0] = port A
sci_ports[X] = port B
In this case, the new port mapped at index zero will have associated data
that was used for earlycon.
In case this happens, after Linux boot, any access to the serial port that
maps on sci_ports[0] (port A) will block the serial port that was used as
earlycon (port B).
To fix this, add early_console_exit() that clean the sci_ports[0] at
earlycon exit time.
Fixes: 0b0cced19a ("serial: sh-sci: Add CONFIG_SERIAL_EARLYCON support")
Cc: stable@vger.kernel.org
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@bp.renesas.com>
Link: https://lore.kernel.org/r/20241106120118.1719888-4-claudiu.beznea.uj@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The receiver is supposed to be enabled in the startup() callback and not
in set_termios() which is called also during console setup.
This specifically avoids accepting input before the port has been opened
(and interrupts enabled), something which can also break the GENI
firmware (cancel fails and after abort, the "stale" counter handling
appears to be broken so that later input is not processed until twelve
chars have been received).
There also does not appear to be any need to keep the receiver disabled
while updating the port settings.
Since commit 6f3c3cafb1 ("serial: qcom-geni: disable interrupts during
console writes") the calls to manipulate the secondary interrupts, which
were done without holding the port lock, can also lead to the receiver
being left disabled when set_termios() races with the console code (e.g.
when init opens the tty during boot). This can manifest itself as a
serial getty not accepting input.
The calls to stop and start rx in set_termios() can similarly race with
DMA completion and, for example, cause the DMA buffer to be unmapped
twice or the mapping to be leaked.
Fix this by only enabling the receiver during startup and while holding
the port lock to avoid racing with the console code.
Fixes: 6f3c3cafb1 ("serial: qcom-geni: disable interrupts during console writes")
Fixes: 2aaa43c707 ("tty: serial: qcom-geni-serial: add support for serial engine DMA")
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Cc: stable@vger.kernel.org # 6.3
Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20241009145110.16847-6-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Make sure to wait for the DMA transfer to complete when cancelling the
rx command on stop_rx(). This specifically prevents the DMA completion
interrupt from firing after rx has been restarted, something which can
lead to an IOMMU fault and hosed rx when the interrupt handler unmaps
the DMA buffer for the new command:
qcom_geni_serial 988000.serial: serial engine reports 0 RX bytes in!
arm-smmu 15000000.iommu: FSR = 00000402 [Format=2 TF], SID=0x563
arm-smmu 15000000.iommu: FSYNR0 = 00210013 [S1CBNDX=33 WNR PLVL=3]
Bluetooth: hci0: command 0xfc00 tx timeout
Bluetooth: hci0: Reading QCA version information failed (-110)
Also add the missing state machine reset which is needed in case
cancellation fails.
Fixes: 2aaa43c707 ("tty: serial: qcom-geni-serial: add support for serial engine DMA")
Cc: stable@vger.kernel.org # 6.3
Cc: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20241009145110.16847-5-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit 35781d8356.
Hibernation is not supported on Qualcomm platforms with mainline
kernels yet a broken vendor implementation for the GENI serial driver
made it upstream.
This is effectively dead code that cannot be tested and should just be
removed, but if these paths were ever hit for an open non-console port
they would crash the machine as the driver would fail to enable clocks
during restore() (i.e. all ports would have to be closed by drivers and
user space before hibernating the system to avoid this as a comment in
the code hinted at).
The broken implementation also added a random call to enable the
receiver in the port setup code where it does not belong and which
enables the receiver prematurely for console ports.
Fixes: 35781d8356 ("tty: serial: qcom-geni-serial: Add support for Hibernation feature")
Cc: stable@vger.kernel.org # 6.2
Cc: Aniket Randive <quic_arandive@quicinc.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20241009145110.16847-3-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When sending data using DMA at high baudrate (4 Mbdps in local test case) to
a device with small RX buffer which keeps asserting RTS after every received
byte, it is possible that the iMX UART driver would not recognize the falling
edge of RTS input signal and get stuck, unable to transmit any more data.
This condition happens when the following sequence of events occur:
- imx_uart_mctrl_check() is called at some point and takes a snapshot of UART
control signal status into sport->old_status using imx_uart_get_hwmctrl().
The RTSS/TIOCM_CTS bit is of interest here (*).
- DMA transfer occurs, the remote device asserts RTS signal after each byte.
The i.MX UART driver recognizes each such RTS signal change, raises an
interrupt with USR1 register RTSD bit set, which leads to invocation of
__imx_uart_rtsint(), which calls uart_handle_cts_change().
- If the RTS signal is deasserted, uart_handle_cts_change() clears
port->hw_stopped and unblocks the port for further data transfers.
- If the RTS is asserted, uart_handle_cts_change() sets port->hw_stopped
and blocks the port for further data transfers. This may occur as the
last interrupt of a transfer, which means port->hw_stopped remains set
and the port remains blocked (**).
- Any further data transfer attempts will trigger imx_uart_mctrl_check(),
which will read current status of UART control signals by calling
imx_uart_get_hwmctrl() (***) and compare it with sport->old_status .
- If current status differs from sport->old_status for RTS signal,
uart_handle_cts_change() is called and possibly unblocks the port
by clearing port->hw_stopped .
- If current status does not differ from sport->old_status for RTS
signal, no action occurs. This may occur in case prior snapshot (*)
was taken before any transfer so the RTS is deasserted, current
snapshot (***) was taken after a transfer and therefore RTS is
deasserted again, which means current status and sport->old_status
are identical. In case (**) triggered when RTS got asserted, and
made port->hw_stopped set, the port->hw_stopped will remain set
because no change on RTS line is recognized by this driver and
uart_handle_cts_change() is not called from here to unblock the
port->hw_stopped.
Update sport->old_status in __imx_uart_rtsint() accordingly to make
imx_uart_mctrl_check() detect such RTS change. Note that TIOCM_CAR
and TIOCM_RI bits in sport->old_status do not suffer from this problem.
Fixes: ceca629e0b ("[ARM] 2971/1: i.MX uart handle rts irq")
Cc: stable <stable@kernel.org>
Reviewed-by: Esben Haabendal <esben@geanix.com>
Signed-off-by: Marek Vasut <marex@denx.de>
Link: https://lore.kernel.org/r/20241002184133.19427-1-marex@denx.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.
auto-generated by the following:
for i in `git grep -l -w asm/unaligned.h`; do
sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
no_llseek had been defined to NULL two years ago, in commit 868941b144
("fs: remove no_llseek")
To quote that commit,
At -rc1 we'll need do a mechanical removal of no_llseek -
git grep -l -w no_llseek | grep -v porting.rst | while read i; do
sed -i '/\<no_llseek\>/d' $i
done
would do it.
Unfortunately, that hadn't been done. Linus, could you do that now, so
that we could finally put that thing to rest? All instances are of the
form
.llseek = no_llseek,
so it's obviously safe.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull tty / serial driver updates from Greg KH:
"Here is the "big" set of tty/serial driver updates for 6.12-rc1.
Nothing major in here, just nice forward progress in the slow cleanup
of the serial apis, and lots of other driver updates and fixes.
Included in here are:
- serial api updates from Jiri to make things more uniform and sane
- 8250_platform driver cleanups
- samsung serial driver fixes and updates
- qcom-geni serial driver fixes from Johan for the bizarre UART
engine that that chip seems to have. Hopefully it's in a better
state now, but hardware designers still seem to come up with more
ways to make broken UARTS 40+ years after this all should have
finished.
- sc16is7xx driver updates
- omap 8250 driver updates
- 8250_bcm2835aux driver updates
- a few new serial driver bindings added
- other serial minor driver updates
All of these have been in linux-next for a long time with no reported
problems"
* tag 'tty-6.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (65 commits)
tty: serial: samsung: Fix serial rx on Apple A7-A9
tty: serial: samsung: Fix A7-A11 serial earlycon SError
tty: serial: samsung: Use bit manipulation macros for APPLE_S5L_*
tty: rp2: Fix reset with non forgiving PCIe host bridges
serial: 8250_aspeed_vuart: Enable module autoloading
serial: qcom-geni: fix polled console corruption
serial: qcom-geni: disable interrupts during console writes
serial: qcom-geni: fix console corruption
serial: qcom-geni: introduce qcom_geni_serial_poll_bitfield()
serial: qcom-geni: fix arg types for qcom_geni_serial_poll_bit()
soc: qcom: geni-se: add GP_LENGTH/IRQ_EN_SET/IRQ_EN_CLEAR registers
serial: qcom-geni: fix false console tx restart
serial: qcom-geni: fix fifo polling timeout
tty: hvc: convert comma to semicolon
mxser: convert comma to semicolon
serial: 8250_bcm2835aux: Fix clock imbalance in PM resume
serial: sc16is7xx: convert bitmask definitions to use BIT() macro
serial: sc16is7xx: fix copy-paste errors in EFR_SWFLOWx_BIT constants
serial: sc16is7xx: remove SC16IS7XX_MSR_DELTA_MASK
serial: xilinx_uartps: Make cdns_rs485_supported static
...
Pull sched_ext support from Tejun Heo:
"This implements a new scheduler class called ‘ext_sched_class’, or
sched_ext, which allows scheduling policies to be implemented as BPF
programs.
The goals of this are:
- Ease of experimentation and exploration: Enabling rapid iteration
of new scheduling policies.
- Customization: Building application-specific schedulers which
implement policies that are not applicable to general-purpose
schedulers.
- Rapid scheduler deployments: Non-disruptive swap outs of scheduling
policies in production environments"
See individual commits for more documentation, but also the cover letter
for the latest series:
Link: https://lore.kernel.org/all/20240618212056.2833381-1-tj@kernel.org/
* tag 'sched_ext-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (110 commits)
sched: Move update_other_load_avgs() to kernel/sched/pelt.c
sched_ext: Don't trigger ops.quiescent/runnable() on migrations
sched_ext: Synchronize bypass state changes with rq lock
scx_qmap: Implement highpri boosting
sched_ext: Implement scx_bpf_dispatch[_vtime]_from_dsq()
sched_ext: Compact struct bpf_iter_scx_dsq_kern
sched_ext: Replace consume_local_task() with move_local_task_to_local_dsq()
sched_ext: Move consume_local_task() upward
sched_ext: Move sanity check and dsq_mod_nr() into task_unlink_from_dsq()
sched_ext: Reorder args for consume_local/remote_task()
sched_ext: Restructure dispatch_to_local_dsq()
sched_ext: Fix processs_ddsp_deferred_locals() by unifying DTL_INVALID handling
sched_ext: Make find_dsq_for_dispatch() handle SCX_DSQ_LOCAL_ON
sched_ext: Refactor consume_remote_task()
sched_ext: Rename scx_kfunc_set_sleepable to unlocked and relocate
sched_ext: Add missing static to scx_dump_data
sched_ext: Add missing static to scx_has_op[]
sched_ext: Temporarily work around pick_task_scx() being called without balance_scx()
sched_ext: Add a cgroup scheduler which uses flattened hierarchy
sched_ext: Add cgroup support
...
Pull printk updates from Petr Mladek:
"This is the "last" part of the support for the new nbcon consoles.
Where "nbcon" stays for "No Big console lock CONsoles" aka not under
the console_lock.
New callbacks are added to struct console:
- write_thread() for flushing nbcon consoles in task context.
- write_atomic() for flushing nbcon consoles in atomic context,
including NMI.
- con->device_lock() and device_unlock() for taking the driver
specific lock, for example, port->lock.
New printk-specific kthreads are created:
- per-console kthreads which get responsible for flushing normal
priority messages on nbcon consoles.
- thread which gets responsible for flushing normal priority messages
on all consoles when CONFIG_RT enabled.
The new callbacks are called under a special per-console lock which
has already been added back in v6.7. It allows to distinguish three
severities: normal, emergency, and panic. A context with a higher
priority could take over the ownership when it is safe even in the
middle of handling a record. The panic context could do it even when
it is not safe. But it is allowed only for the final desperate flush
before entering the infinite loop.
The new lock helps to flush the messages directly in emergency and
panic contexts. But it is not enough in all situations:
- console_lock() is still need for synchronization against boot
consoles.
- con->device_lock() is need for synchronization against other
operations on the same HW, e.g. serial port speed setting,
non-printk related read/write.
The dependency on con->device_lock() is mutual. Any code taking the
driver specific lock has to acquire the related nbcon console context
as well. For example, see the new uart_port_lock() API. It provides
the necessary synchronization against emergency and panic contexts
where the messages are flushed only under the new per-console lock.
Maybe surprisingly, a quite tricky part is the decision how to flush
the consoles in various situations. It has to take into account:
- message priority: normal, emergency, panic
- scheduling context: task, atomic, deferred_legacy
- registered consoles: boot, legacy, nbcon
- threads are running: early boot, suspend, shutdown, panic
- caller: printk(), pr_flush(), printk_flush_in_panic(),
console_unlock(), console_start(), ...
The primary decision is made in printk_get_console_flush_type(). It
creates a hint what the caller should do:
- flush nbcon consoles directly or via the kthread
- call the legacy loop (console_unlock()) directly or via irq_work
The existing behavior is preserved for the legacy consoles. The only
exception is that they are not longer flushed directly from printk()
in panic() before CPUs are stopped. But this blocking happens only
when at least one nbcon console is registered. The motivation is to
increase a chance to produce the crash dump. They legacy consoles
might create a deadlock in compare with nbcon consoles. The nbcon
console should allow to see the messages even when the crash dump
fails.
There are three possible ways how nbcon consoles are flushed:
- The per-nbcon-console kthread is responsible for flushing messages
added with the normal priority. This is the default mode.
- The legacy loop, aka console_unlock(), is used when there is still
a boot console registered. There is no easy way how to match an
early console driver with a nbcon console driver. And the
console_lock() provides the only reliable serialization at the
moment.
The legacy loop uses either con->write_atomic() or
con->write_thread() callbacks depending on whether it is allowed to
schedule. The atomic variant has to be used from printk().
- In other situations, the messages are flushed directly using
write_atomic() which can be called in any context, including NMI.
It is primary needed during early boot or shutdown, in emergency
situations, and panic.
The emergency priority is used by a code called within
nbcon_cpu_emergency_enter()/exit(). At the moment, it is used in four
situations: WARN(), Oops, lockdep, and RCU stall reports.
Finally, there is no nbcon console at the moment. It means that the
changes should _not_ modify the existing behavior. The only exception
is CONFIG_RT which would force offloading the legacy loop, for normal
priority context, into the dedicated kthread"
* tag 'printk-for-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (54 commits)
printk: Avoid false positive lockdep report for legacy printing
printk: nbcon: Assign nice -20 for printing threads
printk: Implement legacy printer kthread for PREEMPT_RT
tty: sysfs: Add nbcon support for 'active'
proc: Add nbcon support for /proc/consoles
proc: consoles: Add notation to c_start/c_stop
printk: nbcon: Show replay message on takeover
printk: Provide helper for message prepending
printk: nbcon: Rely on kthreads for normal operation
printk: nbcon: Use thread callback if in task context for legacy
printk: nbcon: Relocate nbcon_atomic_emit_one()
printk: nbcon: Introduce printer kthreads
printk: nbcon: Init @nbcon_seq to highest possible
printk: nbcon: Add context to usable() and emit()
printk: Flush console on unregister_console()
printk: Fail pr_flush() if before SYSTEM_SCHEDULING
printk: nbcon: Add function for printers to reacquire ownership
printk: nbcon: Use raw_cpu_ptr() instead of open coding
printk: Use the BITS_PER_LONG macro
lockdep: Mark emergency sections in lockdep splats
...
Apple's earlier SoCs, like A7-A11, requires 32-bit writes for the serial
port. Otherwise, a SError happens when writing to UTXH (+0x20). This only
manifested in earlycon as reg-io-width in the device tree is consulted
for normal serial writes.
Change the iotype of the port to UPIO_MEM32, to allow the serial port to
function on A7-A11 SoCs. This change does not appear to affect Apple M1 and
above.
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Tested-by: Janne Grunau <j@jannau.net>
Signed-off-by: Nick Chan <towinchenmi@gmail.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>
Link: https://lore.kernel.org/r/20240911050741.14477-3-towinchenmi@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The write to RP2_GLOBAL_CMD followed by an immediate read of
RP2_GLOBAL_CMD in rp2_reset_asic() is intented to flush out the write,
however by then the device is already in reset and cannot respond to a
memory cycle access.
On platforms such as the Raspberry Pi 4 and others using the
pcie-brcmstb.c driver, any memory access to a device that cannot respond
is met with a fatal system error, rather than being substituted with all
1s as is usually the case on PC platforms.
Swapping the delay and the read ensures that the device has finished
resetting before we attempt to read from it.
Fixes: 7d9f49afa4 ("serial: rp2: New driver for Comtrol RocketPort 2 cards")
Cc: stable <stable@kernel.org>
Suggested-by: Jim Quinlan <james.quinlan@broadcom.com>
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://lore.kernel.org/r/20240906225435.707837-1-florian.fainelli@broadcom.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The polled UART operations are used by the kernel debugger (KDB, KGDB),
which can interrupt the kernel at any point in time. The current
Qualcomm GENI implementation does not really work when there is on-going
serial output as it inadvertently "hijacks" the current tx command,
which can result in both the initial debugger output being corrupted as
well as the corruption of any on-going serial output (up to 4k
characters) when execution resumes:
0190: abcdefghijklmnopqrstuvwxyz0123456789 0190: abcdefghijklmnopqrstuvwxyz0123456789
0191: abcdefghijklmnop[ 50.825552] sysrq: DEBUG
qrstuvwxyz0123456789 0191: abcdefghijklmnopqrstuvwxyz0123456789
Entering kdb (current=0xffff53510b4cd280, pid 640) on processor 2 due to Keyboard Entry
[2]kdb> go
omlji3h3h2g2g1f1f0e0ezdzdycycxbxbwawav :t72r2rp
o9n976k5j5j4i4i3h3h2g2g1f1f0e0ezdzdycycxbxbwawavu:t7t8s8s8r2r2q0q0p
o9n9n8ml6k6k5j5j4i4i3h3h2g2g1f1f0e0ezdzdycycxbxbwawav v u:u:t9t0s4s4rq0p
o9n9n8m8m7l7l6k6k5j5j40q0p p o
o9n9n8m8m7l7l6k6k5j5j4i4i3h3h2g2g1f1f0e0ezdzdycycxbxbwawav :t8t9s4s4r4r4q0q0p
Fix this by making sure that the polled output implementation waits for
the tx fifo to drain before cancelling any on-going longer transfers. As
the polled code cannot take any locks, leave the state variables as they
are and instead make sure that the interrupt handler always starts a new
tx command when there is data in the write buffer.
Since the debugger can interrupt the interrupt handler when it is
writing data to the tx fifo, it is currently not possible to fully
prevent losing up to 64 bytes of tty output on resume.
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Cc: stable@vger.kernel.org # 4.17
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240906131336.23625-9-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Disable the GENI interrupts during console writes to reduce the risk of
having interrupt handlers spinning on the port lock on other cores for
extended periods of time.
This can, for example, reduce the total amount of time spent in the
interrupt handler during boot of the x1e80100 CRD by up to a factor nine
(e.g. from 274 ms to 30 ms) while the worst case processing time drops
from 19 ms to 8 ms.
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240906131336.23625-8-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The Qualcomm serial console implementation is broken and can lose
characters when the serial port is also used for tty output.
Specifically, the console code only waits for the current tx command to
complete when all data has already been written to the fifo. When there
are on-going longer transfers this often means that console output is
lost when the console code inadvertently "hijacks" the current tx
command instead of starting a new one.
This can, for example, be observed during boot when console output that
should have been interspersed with init output is truncated:
[ 9.462317] qcom-snps-eusb2-hsphy fde000.phy: Registered Qcom-eUSB2 phy
[ OK ] Found device KBG50ZNS256G KIOXIA Wi[ 9.471743ndows.
[ 9.539915] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
Add a new state variable to track how much data has been written to the
fifo and use it to determine when the fifo and shift register are both
empty. This is needed since there is currently no other known way to
determine when the shift register is empty.
This in turn allows the console code to interrupt long transfers without
losing data.
Note that the oops-in-progress case is similarly broken as it does not
cancel any active command and also waits for the wrong status flag when
attempting to drain the fifo (TX_FIFO_NOT_EMPTY_EN is only set when
cancelling a command leaves data in the fifo).
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Fixes: a1fee899e5 ("tty: serial: qcom_geni_serial: Fix softlock")
Fixes: 9e957a1550 ("serial: qcom-geni: Don't cancel/abort if we can't get the port lock")
Cc: stable@vger.kernel.org # 4.17
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240906131336.23625-7-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 663abb1a7a ("tty: serial: qcom_geni_serial: Fix UART hang")
addressed an issue with stalled tx after the console code interrupted
the last bytes of a tx command by reenabling the watermark interrupt if
there is data in write buffer. This can however break software flow
control by re-enabling tx after the user has stopped it.
Address the original issue by not clearing the CMD_DONE flag after
polling for command completion. This allows the interrupt handler to
start another transfer when the CMD_DONE interrupt has not been disabled
due to flow control.
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Fixes: 663abb1a7a ("tty: serial: qcom_geni_serial: Fix UART hang")
Cc: stable@vger.kernel.org # 4.17
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240906131336.23625-3-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The qcom_geni_serial_poll_bit() can be used to wait for events like
command completion and is supposed to wait for the time it takes to
clear a full fifo before timing out.
As noted by Doug, the current implementation does not account for start,
stop and parity bits when determining the timeout. The helper also does
not currently account for the shift register and the two-word
intermediate transfer register.
A too short timeout can specifically lead to lost characters when
waiting for a transfer to complete as the transfer is cancelled on
timeout.
Instead of determining the poll timeout on every call, store the fifo
timeout when updating it in set_termios() and make sure to take the
shift and intermediate registers into account. Note that serial core has
already added a 20 ms margin to the fifo timeout.
Also note that the current uart_fifo_timeout() interface does
unnecessary calculations on every call and did not exist in earlier
kernels so only store its result once. This facilitates backports too as
earlier kernels can derive the timeout from uport->timeout, which has
since been removed.
Fixes: c4f528795d ("tty: serial: msm_geni_serial: Add serial driver support for GENI based QUP")
Cc: stable@vger.kernel.org # 4.17
Reported-by: Douglas Anderson <dianders@chromium.org>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240906131336.23625-2-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull bpf/master to receive baebe9aaba ("bpf: allow passing struct
bpf_iter_<type> as kfunc arguments") and related changes in preparation for
the DSQ iterator patchset.
Signed-off-by: Tejun Heo <tj@kernel.org>
Claudiu Beznea
Günther Noack
Sean Anderson
John Ogness
Jiri Slaby (SUSE)
Masahiro Yamada
Ben Wolsieffer
Ilpo Järvinen
Inochi Amaoto
Arnd Bergmann
Kartik Rajput
Bin Liu
Filip Brozovic
Greg Kroah-Hartman
Nicolas Bouchinet
Johan Hovold
Marek Vasut
Longlong Xia
Jeongjun Park
Al Viro
Linus Torvalds
Nick Chan
Florian Fainelli
Liao Chen
Douglas Anderson
Tejun Heo
Chen Ni
Stefan Wahren