tty: hvc: Don't enable the RISC-V SBI console by default

The new SBI console has the same problem as the old one: there's only
one shared backing hardware and no synchronization, so the two drivers

tty: hvc: Don't enable the RISC-V SBI console by default

The new SBI console has the same problem as the old one: there's only
one shared backing hardware and no synchronization, so the two drivers
end up stepping on each other. This was the same issue the old SBI-0.1
console drivers had, but that was disabled by default when SBI-0.1 was.

So just mark the new driver as nonportable.

Reported-by: Emil Renner Berthing <[email protected]>
Fixes: 88ead68e764c ("tty: Add SBI debug console support to HVC SBI driver")
Signed-off-by: Palmer Dabbelt <[email protected]>
Reviewed-by: Paul Walmsley <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
Reviewed-by: Conor Dooley <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: Add SBI debug console support to HVC SBI driver

RISC-V SBI specification supports advanced debug console
support via SBI DBCN extension.

Extend the HVC SBI driver to support it.

Signed-off-by

tty: Add SBI debug console support to HVC SBI driver

RISC-V SBI specification supports advanced debug console
support via SBI DBCN extension.

Extend the HVC SBI driver to support it.

Signed-off-by: Atish Patra <[email protected]>
Signed-off-by: Anup Patel <[email protected]>
Reviewed-by: Andrew Jones <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>

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tty: hvc: dcc: Bind driver to CPU core0 for reads and writes

Some external debuggers do not handle reads/writes from/to DCC
on secondary cores. Each core has its own DCC device registers,
so when a

tty: hvc: dcc: Bind driver to CPU core0 for reads and writes

Some external debuggers do not handle reads/writes from/to DCC
on secondary cores. Each core has its own DCC device registers,
so when a core reads or writes from/to DCC, it only accesses
its own DCC device. Since kernel code can run on any core,
every time the kernel wants to write to the console, it might
write to a different DCC.

In SMP mode, external debugger creates multiple windows, and
each window shows the DCC output only from that core's DCC.
The result is that console output is either lost or scattered
across windows.

Selecting this debug option will enable code that serializes all
console input and output to core 0. The DCC driver will create
input and output FIFOs that all cores will use. Reads and writes
from/to DCC are handled by a workqueue that runs only core 0.

This is a debug feature to be used only in early stage development
where debug serial console support would not be present. It disables
PM feature like CPU hotplug and is not suitable for production
environment.

Signed-off-by: Shanker Donthineni <[email protected]>
Acked-by: Adam Wallis <[email protected]>
Signed-off-by: Timur Tabi <[email protected]>
Signed-off-by: Elliot Berman <[email protected]>
Signed-off-by: Sai Prakash Ranjan <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: hvc: fix link error with CONFIG_SERIAL_CORE_CONSOLE=n

aarch64-linux-gnu-ld: drivers/tty/hvc/hvc_dcc.o: in function `dcc_early_write':
hvc_dcc.c:(.text+0x164): undefined reference to `uart_conso

tty: hvc: fix link error with CONFIG_SERIAL_CORE_CONSOLE=n

aarch64-linux-gnu-ld: drivers/tty/hvc/hvc_dcc.o: in function `dcc_early_write':
hvc_dcc.c:(.text+0x164): undefined reference to `uart_console_write'

The driver uses the uart_console_write(), but SERIAL_CORE_CONSOLE is not
selected, so uart_console_write is not defined, then we get the error.
Fix this by selecting SERIAL_CORE_CONSOLE.

Fixes: d1a1af2cdf19 ("hvc: dcc: Add earlycon support")
Reported-by: Hulk Robot <[email protected]>
Signed-off-by: Yang Yingliang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: riscv: Using RISCV_SBI_V01 instead of RISCV_SBI

As shown in SBI v0.2, the legacy console SBI functions (sbi_console_getchar()
and sbi_console_putchar()) are expected to be deprecated; they have

tty: riscv: Using RISCV_SBI_V01 instead of RISCV_SBI

As shown in SBI v0.2, the legacy console SBI functions (sbi_console_getchar()
and sbi_console_putchar()) are expected to be deprecated; they have no replacement.

Let's HVC_RISCV_SBI and SERIAL_EARLYCON_RISCV_SBI depends on RISCV_SBI_V01.

Fixes: efca13989250 ("RISC-V: Introduce a new config for SBI v0.1")
Signed-off-by: Kefeng Wang <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
Signed-off-by: Palmer Dabbelt <[email protected]>

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tty: source all tty Kconfig files in one place

'source' (include) all of the tty/*/Kconfig files from
drivers/tty/Kconfig instead of from drivers/char/Kconfig.
This consolidates them both in source

tty: source all tty Kconfig files in one place

'source' (include) all of the tty/*/Kconfig files from
drivers/tty/Kconfig instead of from drivers/char/Kconfig.
This consolidates them both in source code and in menu
presentation to the user.

Move hvc/Kconfig and serial/Kconfig 'source' lines into the
if TTY/endif block and remove the if TTY/endif blocks from
those 2 files.

Cc: [email protected]
Cc: Jiri Slaby <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Suggested-by: Jiri Slaby <[email protected]>
Suggested-by: Arnd Bergmann <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Signed-off-by: Randy Dunlap <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: Fix Kconfig indentation, continued

Adjust indentation from seven spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig

Signed-off-

tty: Fix Kconfig indentation, continued

Adjust indentation from seven spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig

Signed-off-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: Fix Kconfig indentation

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig

Signed-off-by: Krzysztof Koz

tty: Fix Kconfig indentation

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:
$ sed -e 's/^ /\t/' -i */Kconfig

Signed-off-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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riscv: don't allow selecting SBI based drivers for M-mode

When running in M-mode we can't use SBI based drivers. Add a new
CONFIG_RISCV_SBI that drivers that do SBI calls can depend on
instead.

Si

riscv: don't allow selecting SBI based drivers for M-mode

When running in M-mode we can't use SBI based drivers. Add a new
CONFIG_RISCV_SBI that drivers that do SBI calls can depend on
instead.

Signed-off-by: Damien Le Moal <[email protected]>
Reviewed-by: Anup Patel <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Paul Walmsley <[email protected]>

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tty: remove redundant 'default n' from Kconfig-s

'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.

Also since commit f467c5640c29

tty: remove redundant 'default n' from Kconfig-s

'default n' is the default value for any bool or tristate Kconfig
setting so there is no need to write it explicitly.

Also since commit f467c5640c29 ("kconfig: only write '# CONFIG_FOO
is not set' for visible symbols") the Kconfig behavior is the same
regardless of 'default n' being present or not:

...
One side effect of (and the main motivation for) this change is making
the following two definitions behave exactly the same:

config FOO
bool

config FOO
bool
default n

With this change, neither of these will generate a
'# CONFIG_FOO is not set' line (assuming FOO isn't selected/implied).
That might make it clearer to people that a bare 'default n' is
redundant.
...

Signed-off-by: Bartlomiej Zolnierkiewicz <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: add SPDX identifiers to Kconfig and Makefiles

There were a few Kconfig and Makefiles under drivers/tty/ that were
missing a SPDX identifier. Fix that up so that automated tools can
properly cl

tty: add SPDX identifiers to Kconfig and Makefiles

There were a few Kconfig and Makefiles under drivers/tty/ that were
missing a SPDX identifier. Fix that up so that automated tools can
properly classify all kernel source files.

Cc: Jiri Slaby <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: Rob Herring <[email protected]>
Acked-by: David Sterba <[email protected]>
Reviewed-by: Mukesh Ojha <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers

The blackfin architecture is getting removed, so these drivers
are not needed any more.

Acked-by: Greg Kroah-Hartman <[email protected]

tty: remove bfin_jtag_comm and hvc_bfin_jtag drivers

The blackfin architecture is getting removed, so these drivers
are not needed any more.

Acked-by: Greg Kroah-Hartman <[email protected]>
Acked-by: Aaron Wu <[email protected]>
Signed-off-by: Arnd Bergmann <[email protected]>

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tty: New RISC-V SBI console driver

The RISC-V ISA defines a simple console that is availiable via SBI calls
on all systems. The SBI console is designed to be availiable at all
times, so while it's

tty: New RISC-V SBI console driver

The RISC-V ISA defines a simple console that is availiable via SBI calls
on all systems. The SBI console is designed to be availiable at all
times, so while it's most natural to use this as an early printk target
it's also possible to use this as the system console when there isn't a
better one availiable.

This patch adds support for the RISC-V SBI console via the HVC
infastructure. It's entirely independent from our early printk support,
which results in early boot messages appearing twice over the SBI
console. As far as I can tell that's the fault of our early printk
support (we should support earlycon) as opposed to this driver.

There is one checkpatch.pl warning here: to check the MAINTAINERS file.
They're all matched by the "K: riscv" line.

Signed-off-by: Palmer Dabbelt <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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x86/lguest: Remove lguest support

Lguest seems to be rather unused these days. It has seen only patches
ensuring it still builds the last two years and its official state is
"Odd Fixes".

Remove it

x86/lguest: Remove lguest support

Lguest seems to be rather unused these days. It has seen only patches
ensuring it still builds the last two years and its official state is
"Odd Fixes".

Remove it in order to be able to clean up the paravirt code.

Signed-off-by: Juergen Gross <[email protected]>
Acked-by: Rusty Russell <[email protected]>
Acked-by: Thomas Gleixner <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

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s390/hvc_iucv: fix broken Kconfig select statement

Select statements in Kconfig do not necessarily enable all required
dependencies and can lead to broken configs. This is also the case
for the "sel

s390/hvc_iucv: fix broken Kconfig select statement

Select statements in Kconfig do not necessarily enable all required
dependencies and can lead to broken configs. This is also the case
for the "select IUCV" statement within HVC_IUCV:

warning: (HVC_IUCV) selects IUCV which has unmet direct
dependencies (NET && S390)

Just add the missing "depends on NET" to avoid broken configs.

Signed-off-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>

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ARM64: TTY: hvc_dcc: Add support for ARM64 dcc

Add support for debug communications channel based
hvc console for arm64 cpus.

Signed-off-by: Abhimanyu Kapur <[email protected]>
Signed-off-by:

ARM64: TTY: hvc_dcc: Add support for ARM64 dcc

Add support for debug communications channel based
hvc console for arm64 cpus.

Signed-off-by: Abhimanyu Kapur <[email protected]>
Signed-off-by: Timur Tabi <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty/hvc: remove celleb-only beat driver

The beat hvc driver is only used by celleb.
celleb has been dropped [1], so drop the drivers.

[1] http://patchwork.ozlabs.org/patch/451730/

CC: Greg Kroah-H

tty/hvc: remove celleb-only beat driver

The beat hvc driver is only used by celleb.
celleb has been dropped [1], so drop the drivers.

[1] http://patchwork.ozlabs.org/patch/451730/

CC: Greg Kroah-Hartman <[email protected]>
CC: Jiri Slaby <[email protected]>
CC: Valentin Rothberg <[email protected]>
CC: [email protected]
CC: [email protected]
Signed-off-by: Daniel Axtens <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty: Added a CONFIG_TTY option to allow removal of TTY

The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-m

tty: Added a CONFIG_TTY option to allow removal of TTY

The option allows you to remove TTY and compile without errors. This
saves space on systems that won't support TTY interfaces anyway.
bloat-o-meter output is below.

The bulk of this patch consists of Kconfig changes adding "depends on
TTY" to various serial devices and similar drivers that require the TTY
layer. Ideally, these dependencies would occur on a common intermediate
symbol such as SERIO, but most drivers "select SERIO" rather than
"depends on SERIO", and "select" does not respect dependencies.

bloat-o-meter output comparing our previous minimal to new minimal by
removing TTY. The list is filtered to not show removed entries with awk
'$3 != "-"' as the list was very long.

add/remove: 0/226 grow/shrink: 2/14 up/down: 6/-35356 (-35350)
function old new delta
chr_dev_init 166 170 +4
allow_signal 80 82 +2
static.__warned 143 142 -1
disallow_signal 63 62 -1
__set_special_pids 95 94 -1
unregister_console 126 121 -5
start_kernel 546 541 -5
register_console 593 588 -5
copy_from_user 45 40 -5
sys_setsid 128 120 -8
sys_vhangup 32 19 -13
do_exit 1543 1526 -17
bitmap_zero 60 40 -20
arch_local_irq_save 137 117 -20
release_task 674 652 -22
static.spin_unlock_irqrestore 308 260 -48

Signed-off-by: Joe Millenbach <[email protected]>
Reviewed-by: Jamey Sharp <[email protected]>
Reviewed-by: Josh Triplett <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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tty/serial: remove CONFIG_EXPERIMENTAL dependencies

As discussed at the kernel summit this year, CONFIG_EXPERIMENTAL means
nothing, so let's get rid of it.

Cc: Kees Cook <[email protected]>
Cc:

tty/serial: remove CONFIG_EXPERIMENTAL dependencies

As discussed at the kernel summit this year, CONFIG_EXPERIMENTAL means
nothing, so let's get rid of it.

Cc: Kees Cook <[email protected]>
Cc: Alan Cox <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Stefano Stabellini <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Konrad Rzeszutek Wilk <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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powerpc/hvc_udbg: Don't crash when udbg_putc is NULL

Also while at it, add some help text indicating why you shouldn't
enable that driver under normal circumstances

Signed-off-by: Benjamin Herrensc

powerpc/hvc_udbg: Don't crash when udbg_putc is NULL

Also while at it, add some help text indicating why you shouldn't
enable that driver under normal circumstances

Signed-off-by: Benjamin Herrenschmidt <[email protected]>

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hvc_xen: introduce HVC_XEN_FRONTEND

Introduce a new config option HVC_XEN_FRONTEND to enable/disable the
xenbus based pv console frontend.

Signed-off-by: Stefano Stabellini <[email protected]

hvc_xen: introduce HVC_XEN_FRONTEND

Introduce a new config option HVC_XEN_FRONTEND to enable/disable the
xenbus based pv console frontend.

Signed-off-by: Stefano Stabellini <[email protected]>
Signed-off-by: Konrad Rzeszutek Wilk <[email protected]>

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tty: powerpc: remove hvc_iseries

The PowerPC legacy iSeries platform is being removed, so this code is no
longer needed.

Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Stephen R

tty: powerpc: remove hvc_iseries

The PowerPC legacy iSeries platform is being removed, so this code is no
longer needed.

Cc: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Stephen Rothwell <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>

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powerpc/powernv: Support for OPAL console

This adds a udbg and an hvc console backend for supporting a console
using the OPAL console interfaces.

On OPAL v1 we have hvc0 mapped to whatever console

powerpc/powernv: Support for OPAL console

This adds a udbg and an hvc console backend for supporting a console
using the OPAL console interfaces.

On OPAL v1 we have hvc0 mapped to whatever console the system was
configured for (network or hvsi serial port) via the service
processor.

On OPAL v2 we have hvcN mapped to the Nth console provided by OPAL
which generally corresponds to:

hvc0 : network console (raw protocol)
hvc1 : serial port S1 (hvsi)
hvc2 : serial port S2 (hvsi)

Note: At this point, early debug console only works with OPAL v1
and shouldn't be enabled in a normal kernel.

Signed-off-by: Benjamin Herrenschmidt <[email protected]>

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powerpc/pseries: Re-implement HVSI as part of hvc_vio

On pseries machines, consoles are provided by the hypervisor using
a low level get_chars/put_chars type interface. However, this is
really just

powerpc/pseries: Re-implement HVSI as part of hvc_vio

On pseries machines, consoles are provided by the hypervisor using
a low level get_chars/put_chars type interface. However, this is
really just a transport to the service processor which implements
them either as "raw" console (networked consoles, HMC, ...) or as
"hvsi" serial ports.

The later is a simple packet protocol on top of the raw character
interface that is supposed to convey additional "serial port" style
semantics. In practice however, all it does is provide a way to
read the CD line and set/clear our DTR line, that's it.

We currently implement the "raw" protocol as an hvc console backend
(/dev/hvcN) and the "hvsi" protocol using a separate tty driver
(/dev/hvsi0).

However this is quite impractical. The arbitrary difference between
the two type of devices has been a major source of user (and distro)
confusion. Additionally, there's an additional mini -hvsi implementation
in the pseries platform code for our low level debug console and early
boot kernel messages, which means code duplication, though that low
level variant is impractical as it's incapable of doing the initial
protocol negociation to establish the link to the FSP.

This essentially replaces the dedicated hvsi driver and the platform
udbg code completely by extending the existing hvc_vio backend used
in "raw" mode so that:

- It now supports HVSI as well
- We add support for hvc backend providing tiocm{get,set}
- It also provides a udbg interface for early debug and boot console

This is overall less code, though this will only be obvious once we
remove the old "hvsi" driver, which is still available for now. When
the old driver is enabled, the new code still kicks in for the low
level udbg console, replacing the old mini implementation in the platform
code, it just doesn't provide the higher level "hvc" interface.

In addition to producing generally simler code, this has several benefits
over our current situation:

- The user/distro only has to deal with /dev/hvcN for the hypervisor
console, avoiding all sort of confusion that has plagued us in the past

- The tty, kernel and low level debug console all use the same code
base which supports the full protocol establishment process, thus the
console is now available much earlier than it used to be with the
old HVSI driver. The kernel console works much earlier and udbg is
available much earlier too. Hackers can enable a hard coded very-early
debug console as well that works with HVSI (previously that was only
supported for the "raw" mode).

I've tried to keep the same semantics as hvsi relative to how I react
to things like CD changes, with some subtle differences though:

- I clear DTR on close if HUPCL is set

- Current hvsi triggers a hangup if it detects a up->down transition
on CD (you can still open a console with CD down). My new implementation
triggers a hangup if the link to the FSP is severed, and severs it upon
detecting a up->down transition on CD.

Signed-off-by: Benjamin Herrenschmidt <[email protected]>

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tty: move Kconfig entries into drivers/tty from drivers/char

The Kconfig options for the drivers/tty/ files still were hanging around
in the "big" drivers/char/Kconfig file, so move them to the prop

tty: move Kconfig entries into drivers/tty from drivers/char

The Kconfig options for the drivers/tty/ files still were hanging around
in the "big" drivers/char/Kconfig file, so move them to the proper
location under drivers/tty and drivers/tty/hvc/

Signed-off-by: Greg Kroah-Hartman <[email protected]>

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