It should remove the align-padding before @name.
[yes, there's a "hole" in the structure now, but that's fine, no one
cares. If they do care, the whole thing should be restructured using
pahole to find a better ordering. Removing this field is good as some
drivers have been known to abuse it for other things when they shouldn't
have been doing that. -- gregkh]
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20200114171912.261787-4-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The SUPPORT_SYSRQ is messy: every .c source should define it before
including "serial_core.h" if sysrq is supported or struct uart_port will
differ in sizes. Also this prevents moving to serial_core.c functions:
uart_handle_sysrq_char(), uart_prepare_sysrq_char(),
uart_unlock_and_check_sysrq().
It doesn't save many bytes in the structure, and a better way to reduce
it's size would be making rs485 and iso7816 pointers.
Introduce `has_sysrq` member to be used by serial line drivers further.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-4-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At the current place members those follow are:
: upf_t flags;
: upstat_t status;
: int hw_stopped;
: unsigned int mctrl;
: unsigned int timeout;
: unsigned int type;
: const struct uart_ops *ops;
Together, they give (*ops) 8-byte align on 64-bit platforms.
And `sysrq_ch` introduces 4-byte padding.
On the other side, above:
: struct device *dev;
: unsigned char hub6;
: unsigned char suspended;
: unsigned char unused[2];
: const char *name;
Adds another 4-byte padding.
Moving sysrq members just before `hub6` allows to save 8 bytes
per-uart_port on 64-bit platforms:
On my gcc, x86_64 sizeof(struct uart_port) goes from 528 to 520.
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-3-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version this program is distributed in the
hope that it will be useful but without any warranty without even
the implied warranty of merchantability or fitness for a particular
purpose see the gnu general public license for more details you
should have received a copy of the gnu general public license along
with this program if not write to the free software foundation inc
59 temple place suite 330 boston ma 02111 1307 usa
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 1334 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The converted files are focused at the Kernel internal API,
so, this is a good candidate for the kernel API set of books.
The conversion is actually:
- add blank lines and identation in order to identify paragraphs;
- fix tables markups;
- add some lists markups;
- mark literal blocks;
- adjust title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In the static inline function uart_handle_break() in serial_core.h we
dereference port->cons. That gives an error unless console.h is also
included.
This error hasn't shown up till now because everyone who has defined
SUPPORT_SYSRQ has also included console.h, but it's a bit ugly to make
this requirement. Let's make the include explicit.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Right now serial drivers process sysrq keys deep in their character
receiving code. This means that they've already grabbed their
port->lock spinlock. This can end up getting in the way if we've go
to do serial stuff (especially kgdb) in response to the sysrq.
Serial drivers have various hacks in them to handle this. Looking at
'8250_port.c' you can see that the console_write() skips locking if
we're in the sysrq handler. Looking at 'msm_serial.c' you can see
that the port lock is dropped around uart_handle_sysrq_char().
It turns out that these hacks aren't exactly perfect. If you have
lockdep turned on and use something like the 8250_port hack you'll get
a splat that looks like:
WARNING: possible circular locking dependency detected
[...] is trying to acquire lock:
... (console_owner){-.-.}, at: console_unlock+0x2e0/0x5e4
but task is already holding lock:
... (&port_lock_key){-.-.}, at: serial8250_handle_irq+0x30/0xe4
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&port_lock_key){-.-.}:
_raw_spin_lock_irqsave+0x58/0x70
serial8250_console_write+0xa8/0x250
univ8250_console_write+0x40/0x4c
console_unlock+0x528/0x5e4
register_console+0x2c4/0x3b0
uart_add_one_port+0x350/0x478
serial8250_register_8250_port+0x350/0x3a8
dw8250_probe+0x67c/0x754
platform_drv_probe+0x58/0xa4
really_probe+0x150/0x294
driver_probe_device+0xac/0xe8
__driver_attach+0x98/0xd0
bus_for_each_dev+0x84/0xc8
driver_attach+0x2c/0x34
bus_add_driver+0xf0/0x1ec
driver_register+0xb4/0x100
__platform_driver_register+0x60/0x6c
dw8250_platform_driver_init+0x20/0x28
...
-> #0 (console_owner){-.-.}:
lock_acquire+0x1e8/0x214
console_unlock+0x35c/0x5e4
vprintk_emit+0x230/0x274
vprintk_default+0x7c/0x84
vprintk_func+0x190/0x1bc
printk+0x80/0xa0
__handle_sysrq+0x104/0x21c
handle_sysrq+0x30/0x3c
serial8250_read_char+0x15c/0x18c
serial8250_rx_chars+0x34/0x74
serial8250_handle_irq+0x9c/0xe4
dw8250_handle_irq+0x98/0xcc
serial8250_interrupt+0x50/0xe8
...
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&port_lock_key);
lock(console_owner);
lock(&port_lock_key);
lock(console_owner);
*** DEADLOCK ***
The hack used in 'msm_serial.c' doesn't cause the above splats but it
seems a bit ugly to unlock / lock our spinlock deep in our irq
handler.
It seems like we could defer processing the sysrq until the end of the
interrupt handler right after we've unlocked the port. With this
scheme if a whole batch of sysrq characters comes in one irq then we
won't handle them all, but that seems like it should be a fine
compromise.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This reverts commit c550f01c81.
Turns out the samsung tty driver is mucking around in the "unused" port
fields and this patch breaks that code :(
So we need to fix that driver up before this can be accepted.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steve Sakoman <steve@sakoman.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add the ISO7816 ioctl and associated accessors and data structure.
Drivers can then use this common implementation to handle ISO7816
(smart cards).
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
[ludovic.desroches@microchip.com: squash and rebase, removal of gpios, checkpatch fixes]
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add a "pps_4wire" file to serial ports in sysfs in case the kernel is
configured with CONFIG_PPS_CLIENT_LDISC. Writing 1 to the file enables
the use of CTS instead of DCD for PPS signal input. This is necessary
in case a serial port is not completely wired.
Though this affects PPS processing the patch is against the serial core
as the source of the serial port PPS event dispatching has to be
modified. Furthermore it should be possible to modify the source of
serial port PPS event dispatching before changing the line discipline.
Signed-off-by: Andreas Steinmetz <ast@domdv.de>
Signed-off-by: Steve Sakoman <steve@sakoman.com>
Tested-by: Steve Sakoman <steve@sakoman.com>
Tested-by: Eric Gallimore <egallimore@ucsd.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As part of bringup I ended up wanting to call an earlycon driver by a
name that was exactly 16-bytes big, specifically "qcom_geni_serial".
Unfortunately, when I tried this I found that things compiled just
fine. They just didn't work.
Specifically the compiler felt perfectly justified in initting the
".name" field of "struct earlycon_id" with the full 16-bytes and just
skipping the '\0'. Needless to say, that behavior didn't seem ideal,
but I guess someone must have allowed it for a reason.
One way to fix this is to shorten the name field to 15 bytes and then
add an extra byte after that nobody touches. This should always be
initted to 0 and we're golden.
There are, of course, other ways to fix this too. We could audit all
the users of the "name" field and make them stop at both null
termination or at 16 bytes. We could also just make the name field
much bigger so that we're not likely to run into this. ...but both
seem like we'll just hit the bug again.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This change adds a flag to indicate that a UART is has an external means
of synchronising its FIFO, without needing CTSRTS or XON/XOFF.
This allows us to use the throttle/unthrottle callbacks, without having
to claim other methods of flow control.
Signed-off-by: Jeremy Kerr <jk@ozlabs.org>
Tested-by: Eddie James <eajames@linux.vnet.ibm.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 99492c39f3 ("earlycon: Fix __earlycon_table stride") tried to fix
__earlycon_table stride by forcing the earlycon_id struct alignment to 32
and asking the linker to 32-byte align the __earlycon_table symbol. This
fix was based on commit 07fca0e57f ("tracing: Properly align linker
defined symbols") which tried a similar fix for the tracing subsystem.
However, this fix doesn't quite work because there is no guarantee that
gcc will place structures packed into an array format. In fact, gcc 4.9
chooses to 64-byte align these structs by inserting additional padding
between the entries because it has no clue that they are supposed to be in
an array. If we are unlucky, the linker will assign symbol
"__earlycon_table" to a 32-byte aligned address which does not correspond
to the 64-byte aligned contents of section "__earlycon_table".
To address this same problem, the fix to the tracing system was
subsequently re-implemented using a more robust table of pointers approach
by commits:
3d56e331b6 ("tracing: Replace syscall_meta_data struct array with pointer array")
6549864629 ("tracepoints: Fix section alignment using pointer array")
e4a9ea5ee7 ("tracing: Replace trace_event struct array with pointer array")
Let's use this same "array of pointers to structs" approach for
EARLYCON_TABLE.
Fixes: 99492c39f3 ("earlycon: Fix __earlycon_table stride")
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Suggested-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Tested-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Re-use the object-like macro EARLYCON_USED_OR_UNUSED to mark
`earlycon_acpi_spcr_enable` as maybe_unused.
Fix the following warning (treated as error in W=1)
CC arch/powerpc/kernel/setup-common.o
In file included from ./include/linux/serial_8250.h:14:0,
from arch/powerpc/kernel/setup-common.c:33:
./include/linux/serial_core.h:382:19: error: ‘earlycon_acpi_spcr_enable’ defined but not used [-Werror=unused-const-variable=]
static const bool earlycon_acpi_spcr_enable;
^~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull more ACPI updates from Rafael Wysocki:
"These are mostly fixes and cleanups, a few new quirks, a couple of
updates related to the handling of ACPI tables and ACPICA copyrights
refreshment.
Specifics:
- Update the ACPICA kernel code to upstream revision 20180105
including:
* Assorted fixes (Jung-uk Kim)
* Support for X32 ABI compilation (Anuj Mittal)
* Update of ACPICA copyrights to 2018 (Bob Moore)
- Prepare for future modifications to avoid executing the _STA
control method too early (Hans de Goede)
- Make the processor performance control library code ignore _PPC
notifications if they cannot be handled and fix up the C1 idle
state definition when it is used as a fallback state (Chen Yu,
Yazen Ghannam)
- Make it possible to use the SPCR table on x86 and to replace the
original IORT table with a new one from initrd (Prarit Bhargava,
Shunyong Yang)
- Add battery-related quirks for Asus UX360UA and UX410UAK and add
quirks for table parsing on Dell XPS 9570 and Precision M5530 (Kai
Heng Feng)
- Address static checker warnings in the CPPC code (Gustavo Silva)
- Avoid printing a raw pointer to the kernel log in the smart battery
driver (Greg Kroah-Hartman)"
* tag 'acpi-part2-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI: sbshc: remove raw pointer from printk() message
ACPI: SPCR: Make SPCR available to x86
ACPI / CPPC: Use 64-bit arithmetic instead of 32-bit
ACPI / tables: Add IORT to injectable table list
ACPI / bus: Parse tables as term_list for Dell XPS 9570 and Precision M5530
ACPICA: Update version to 20180105
ACPICA: All acpica: Update copyrights to 2018
ACPI / processor: Set default C1 idle state description
ACPI / battery: Add quirk for Asus UX360UA and UX410UAK
ACPI: processor_perflib: Do not send _PPC change notification if not ready
ACPI / scan: Use acpi_bus_get_status() to initialize ACPI_TYPE_DEVICE devs
ACPI / bus: Do not call _STA on battery devices with unmet dependencies
PCI: acpiphp_ibm: prepare for acpi_get_object_info() no longer returning status
ACPI: export acpi_bus_get_status_handle()
ACPICA: Add a missing pair of parentheses
ACPICA: Prefer ACPI_TO_POINTER() over ACPI_ADD_PTR()
ACPICA: Avoid NULL pointer arithmetic
ACPICA: Linux: add support for X32 ABI compilation
ACPI / video: Use true for boolean value
SPCR is currently only enabled or ARM64 and x86 can use SPCR to setup
an early console.
General fixes include updating Documentation & Kconfig (for x86),
updating comments, and changing parse_spcr() to acpi_parse_spcr(),
and earlycon_init_is_deferred to earlycon_acpi_spcr_enable to be
more descriptive.
On x86, many systems have a valid SPCR table but the table version is
not 2 so the table version check must be a warning.
On ARM64 when the kernel parameter earlycon is used both the early console
and console are enabled. On x86, only the earlycon should be enabled by
by default. Modify acpi_parse_spcr() to allow options for initializing
the early console and console separately.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mark Salter <msalter@redhat.com>
Tested-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The pointed string is never modified from within uart_parse_options, so
it should be marked as const in the function prototype.
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit ef838a81dd ("serial: Add common rs485 device tree parsing
function") consolidated retrieval of rs485 OF properties in a common
helper function but did not #ifdef it to CONFIG_OF. The function is
therefore included on ACPI platforms as well even though it's not used.
On the other hand ACPI platforms with rs485 do exist (e.g. Siemens
IOT2040) and they may leverage _DSD to store rs485 properties. Likewise,
UART platform devices instantiated from an MFD should be able to specify
rs485 properties. In fact, the tty subsystem maintainer had asked for
a "generic" function during review of commit ef838a81dd:
https://marc.info/?l=linux-serial&m=150143441725194&w=4
Thus, instead of constraining the helper to OF platforms, make it
platform-agnostic by converting it to device_property_*() functions
and renaming it accordingly.
In imx.c, move the invocation of uart_get_rs485_mode() from
serial_imx_probe_dt() to serial_imx_probe() so that it also gets called
for non-OF devices.
In omap-serial.c, move its invocation further up within
serial_omap_probe_rs485() so that the RTS polarity can be overridden
with the driver-specific "rs485-rts-active-high" property once we
introduce a generic "rs485-rts-active-low" property.
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Several drivers have the same device tree parsing code. Create
a common helper function for it.
This patch bases on work done by Sascha Hauer.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There is no need to duplicate a flag which IRQ core takes care of.
Replace custom flag by IRQ core API that retrieves its state.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
