Currently sci_dma_rx_push() has to find the active scatterlist itself,
but in some cases the caller already knows.

Hence let the caller pass the scatterlist, and introduce a helper to
find the active DMA request while we're at it.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

During serial port shutdown, the DMA receive worker function may still
be called after the receive DMA cleanup function has been called.
Fix this race condition between work_fn_rx() and sci_rx_dma_release() by
acquiring the port's spinlock in sci_rx_dma_release().
This requires releasing the spinlock in work_fn_rx() before calling (any
function that may call) sci_rx_dma_release().

Terminate all active receive DMA descriptors to release them, and to
make sure no more completions come in.

Do the same in sci_tx_dma_release() for symmetry, although the serial
upper layer will no longer submit more data at this point of time.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is a problem when the sci_dma_rx_complete() is processed
before cancel process of work_fn_rx() completes by rx_timer_fn().
This patch locks work_fn_rx().
Signed-off-by: NKazuya Mizuguchi <kazuya.mizuguchi.ks@renesas.com>
Signed-off-by: NYoshihiro Kaneko <ykaneko0929@gmail.com>
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Resubmission of DMA descriptors is explicitly forbidden by the DMA
engine API.

Hence pass DMA_CTRL_ACK to dmaengine_prep_slave_sg(), and prepare a new
DMA descriptor instead of reusing the old one.
Remove sci_port.desc_rx[], as there's no longer a need to access the
active descriptor.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Simplify the error handling in sci_submit_rx() by
  - Moving it to the end of the function,
  - Just calling dmaengine_terminate_all() instead of calling
    async_tx_ack() for all already submitted descriptors.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As dmaengine_prep_slave_sg() is called with the DMA_CTRL_ACK flag set
for DMA transmit requests, there's no need to explicitly acknowledge DMA
transmit requests in the DMA transmit completion callback.

Hence remove the call to async_tx_ack(), and remove the now unused
dma_async_tx_descriptor pointer in the sci_port structure.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Convert the SCI driver from the SHDMAE-specific partial DMA transfer
handling to the generic dmaengine residual data framework.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Replace open-coded
  - calls to dma_async_tx_descriptor.tx_submit() by calls to the
    dmaengine_submit() helper,
  - dma_cookie_t comparisons by calls to dma_submit_error().
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The mapped transmit buffer is never unmapped. This leaks quite some
mappings, as the mapping is done in uart_ops.startup(), i.e. every time
the device is opened. Unmap the buffer on device close.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Simplify the DMA transmit code by using dma_map_single() instead of
constantly modifying the single-entry scatterlist to match what's
currently being transmitted.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When comparing differently sized types, it's better to use
min_t()/max_t() than adding casts.

Also use "unsigned int" instead of "int", as that's the right type for
the length of an SG entry.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To function correctly in the presence of an IOMMU, the DMA buffers must
be managed using the DMA channel's device instead of the platform
device's device.

Make sure to free the DMA memory before releasing the channel, not
after.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Let sci_request_dma() handle failures to initialize DMA itself.
This way sci_tx_dma_release() and sci_rx_dma_release() don't have to
consider partial initialization, and thus don't need to reset DMA
addresses to DMA_ERROR_CODE, which is not 100% portable access
architectures.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Reformat, grammar improvements, use "ms" instead of "msec".
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make the life of the driver developer/debugger easier:
  - Add __func__ prefix to identical messages,
  - Add DMA directions to messages,
  - Add TX failure messages,
  - Always use "cookie %d" for DMA cookies,
  - "#%d" is reserved for the DMA cookie/descriptor index.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch fix an issue that the driver may cause "nobody cared" IRQ
when this driver detects the overrun flag only.
Signed-off-by: NYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 8b6ff84c ("serial: sh-sci: Fix R-Car SCIF and HSCIF
overrun handling") added overrun handling for (H)SCIF using the SCLSR
register, but also accidentally added a bogus call to
sci_handle_fifo_overrun() in the receive interrupt path.

Remove it again.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Printing an error on memory allocation failures is unnecessary.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Reorder sampling_rate assignment for consistency in all cases of the
switch statement.
Avoid using the ternary conditional operator to make it more clear that
the value is overridden by platform data.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

serial_core.c was moved from drivers/serial/ to drivers/tty/serial/ a
while ago. Remove the path to make it move-proof.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

SCIF_ERROR_CLEAR includes SCIFA_ORER, which exists only on SCIFA/SCIFB
and SCIF on sh7705/sh7720/sh7721.

To fix this:
  1. Remove SCIFA_ORER from the definition of SCIF_ERROR_CLEAR,
  2. During initialization, store the error clear mask to use,
     incorporating the overrun bit only if it applies to the SCxSR
     register.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Expressions involving "BIT(...)" create values of type "long", which is
64-bit on 64-bit.  Hence "~BIT(...)" no longer fits in 32-bit, which
will cause future compiler warnings when assigning to 32-bit variables:

    drivers/tty/serial/sh-sci.c: In function 'sci_init_single':
    drivers/tty/serial/sh-sci.h:58:25: warning: large integer implicitly truncated to unsigned type [-Woverflow]
     #define SCI_ERROR_CLEAR ~(SCI_RESERVED | SCI_PER | SCI_FER | SCI_ORER)
			     ^
    drivers/tty/serial/sh-sci.c:2325:27: note: in expansion of macro 'SCI_ERROR_CLEAR'
       sci_port->error_clear = SCI_ERROR_CLEAR;

As these values are (at most) 32-bit register values anyway, cast them
to "u32" at the definition level to prevent such compiler warnings.
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The #ifdef logic to clear SCxSR bits using RMW on SCIFA/SCIFB and SCIF
variants with some SCIFA features (sh7705/SH7720/sh7721) has several
drawbacks:
  - It wasn't updated for newer R-Mobile variants (APE6),
  - It doesn't correctly handle SoCs with both SCIF and SCIFA/B (e.g.
    R-Car Gen2, but also legacy sh7723/sh7724),
  - It doesn't play well with ARM multi-platform kernels: on R-Car Gen2,
    SCIF/SCIFA/SCIFB/HSCIF were handled differently, depending on
    whether r8a7740 or sh73a0 support was enabled or not,

Replace the #ifdef logic by runtime logic to fix this.

SCIFA/SCIFB and SCIF on sh7705/sh7720/sh7721 use RMW to clear error
bits, other variants use plain stores, as before.

Note that this changes behavior for SCIFA on sh7723/sh7724 (these SoCs
have both SCIF and SCIFA), which didn't use RMW before.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The following race conditions can happen when a serial port is used
as console.

Case1: CPU_B is used to detect an interrupt from a serial port,
       but it can have interrupts disabled during the waiting time.
Case2: CPU_B clears UART_IER just after CPU_A sets UART_IER and then
       a serial port may not make an interrupt.
Case3: CPU_A sets UART_IER just after CPU_B clears UART_IER.
       This is an unexpected behavior for serial8250_console_write().

CPU_A [autoconfig_irq]      |  CPU_B [serial8250_console_write]
----------------------------|---------------------------------------
                            |
probe_irq_on()              |  spin_lock_irqsave(&port->lock,)
serial_outp(,UART_IER,0x0f) |  serial_out(,UART_IER,0)
udelay(20);                 |  uart_console_write()
probe_irq_off()             |
                            |  spin_unlock_irqrestore(&port->lock,)

Case1 and 2 can make autoconfig_irq() failed.
In these cases, the console doesn't work in interrupt mode and
"input overrun" (which can make operation mistakes) can happen
on some systems. Especially in the Case1, It is known that the
problem happens with high rate every boot once it occurs
because the boot sequence is always almost same.

port mutex makes sure that the autoconfig operation is exclusive of
any other concurrent HW access except by the console operation.
console lock is required in autoconfig_irq().
Signed-off-by: NTaichi Kageyama <t-kageyama@cp.jp.nec.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This fixes receiving broken characters on the console from an MPC5125
system when systemd comes up which repeatedly opens and shuts down the
console device.

Trial and error with the needed interval showed that 500 us are good
enough most of the time when using 38400 Bd, so I think 1 ms is a good
compromise between fixing the issue and not penalize faster setups too
much.
Signed-off-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Kconfig currently controlling compilation of this code is:

8250/Kconfig:config SERIAL_8250_LPC18XX
8250/Kconfig:        bool "NXP LPC18xx/43xx serial port support"

...meaning that it currently is not being built as a module by anyone.

When targetting orphaned modular code in non-modular drivers, this
came up.  Joachim indicated that the driver was actually meant to
be tristate but ended up bool by accident.  So here we make it
tristate instead of removing the modular code that was essentially
orphaned.
Suggested-by: NJoachim Eastwood <manabian@gmail.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: NJoachim Eastwood <manabian@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Kconfig for this driver is currently:

config SERIAL_MPSC
        bool "Marvell MPSC serial port support"

...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We leave some tags like MODULE_AUTHOR for documentation purposes.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Kconfig currently controlling compilation of this code is:

drivers/tty/hvc/Kconfig:config HVC_DRIVER
drivers/tty/hvc/Kconfig:        bool

...meaning that it currently is not being built as a module by anyone.

Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only, even
though someone bothered to comment that the code was not used.

Unlike other changes, this driver binds in w/o using module_init,
so we dont have init ordering concerns with this commit.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Acked-by: NMichael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Kconfig currently controlling compilation of this code is:

config.debug:config MAGIC_SYSRQ
      bool "Magic SysRq key"

...meaning that it currently is not being built as a module by anyone.

Lets remove the traces of modularity we can so that when reading the
driver there is less doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We don't delete the module.h include since other parts of the file are
using content from there.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Kconfig currently controlling compilation of this code is:

drivers/tty/Kconfig:config LEGACY_PTYS
drivers/tty/Kconfig:    bool "Legacy (BSD) PTY support"

...and:

drivers/tty/Kconfig:config UNIX98_PTYS
drivers/tty/Kconfig:    bool "Unix98 PTY support" if EXPERT

combined with this:

obj-$(CONFIG_LEGACY_PTYS)       += pty.o
obj-$(CONFIG_UNIX98_PTYS)       += pty.o

...meaning that it currently is not being built as a module by anyone.

Lets remove the traces of modularity we can so that when reading the
driver there is less doubt it is builtin-only.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We don't delete the module.h include since other parts of the file are
using content from there.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

CIR type serial ports aren't real serial ports.

This is just a way to prevent legacy 8250 serial
driver from probing and eventually binding some
resources.

Since in current state such ports aren't providing
any real functionality and it is not possible
to change their type via setserial/ioctl(TIOCSSERIAL)
(due to UPF_FIXED_PORT flag set on them)
it is simpler and cleaner to not register them at all
with serial core.

Print a short message in this case so it is known
to user what has happened.

This way checks for PORT_8250_CIR in serial port
callbacks can be removed too, since they won't
ever be called.
Signed-off-by: NMaciej Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The function tty_insert_flip_string() returns an int and as such it
might fail. So the result is that I kindly asked to insert 48 bytes and
the function only insterted 32.
I have no idea what to do with the remaining 16 so I think dropping them
is the only option. I also increase the buf_overrun counter so userpace
has a clue that we lost bytes.
Signed-off-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Tested-by: NSekhar Nori <nsekhar@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Pull x86 fixes from Thomas Gleixner:
 "Two bugfixes from Andy addressing at least some of the subtle NMI
  related wreckage which has been reported by Sasha Levin"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/nmi/64: Fix a paravirt stack-clobbering bug in the NMI code
  x86/paravirt: Replace the paravirt nop with a bona fide empty function

Pull irq fix from Thomass Gleixner:
 "A bugfix for the atmel aic5 irq chip driver which caches the wrong
  data and thereby breaking resume"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/atmel-aic5: Use per chip mask caches in mask/unmask()

Pull ARM fixes from Russell King:
 "Just two fixes: wire up the new system calls added during the last
  merge window, and fix another user access site"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: alignment: fix alignment handling for uaccess changes
  ARM: wire up new syscalls