Refactor base port operations into new file; 8250_port.c.

Legacy irq handling, RSA port support, port storage for universal
driver, driver definition, module parameters and linkage remain in
8250_core.c

The source file split and resulting modules is diagrammed below:

  8250_core.c ====>   8250_core.c __
              \                     \
               \                     +-- 8250.ko (alias 8250_core)
                \     8250_pnp.c  __/     (universal driver)
                 \
                  =>  8250_port.c __
                                    \
                                     +-- 8250_base.ko
                      8250_dma.c  __/     (port operations)
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If the UART has been in use before this driver was loaded, IRQs might be
active and get fired as soon as we set the handler, which will crash
in the spin_lock_irqsave(&sport->port.lock, flags) because port.lock is
not initialized until the port is added at the end of probe.
Signed-off-by: NDavid Jander <david@protonic.nl>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

To prevent problems with interrupt latency, and due to the fact, that
the error will be counted anyway (icount.overrun), the dev_err is simply
removed.

Background:
If an rx-fifo overflow occurs a dev_err message was called in interrupt
context. Since dev_err messages are written to console in a synchronous way
(unbuffered), and console may be a serial terminal, this leads to a
highly increased interrupt-latency (several milliseconds).
As a result of the high latency more rx-fifo overflows will happen, and
therefore a feedback loop of errors is created.
Signed-off-by: NManfred Schlaegl <manfred.schlaegl@gmx.at>
Acked-By: NAlexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

As can be seen in function uart_insert_char (serial_core) the element
buf_overrun of struct uart_icount is used to count overruns of
tty-buffer.
Added support for counting of overruns in imx driver analogue to
serial_core.
Signed-off-by: NManfred Schlaegl <manfred.schlaegl@gmx.at>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Disable interrupts before requesting them in order to fix a kernel oops
after lauching a kernel via kexec.

Tested on a imx6sl-evk board.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Being a soft core, it can be located not only on PPC or Microblaze
platforms.

Since the driver already does endianness detection we only need to
change the Kconfig to use it in other arches.

This is also done in other softcores as xilinx-spi.
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

SysRq support activation depends on CONFIG_SERIAL_STM32_USART_CONSOLE, but
this config flag does not exists.

This patch fix this by depending on the valid config flag, which is
SERIAL_STM32_CONSOLE.
Reported-by: NAndreas Ruprecht <andreas.ruprecht@fau.de>
Signed-off-by: NMaxime Coquelin <mcoquelin.stm32@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

While UART work in DMA mode, function start_rx will request descriptor
from DMA engine, if there is no left descriptor UART, driver will give
err logs "DMA slave single fail".

currently start_rx is called in set_termios function, so everytime, port
setting will call start_rx once.

Now put start_rx in startup, it will be called once while open the port.
Signed-off-by: NQipan Li <Qipan.Li@csr.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

when UART works in DMA mode and left bytes in rx fifo less than
a dma transfer unit, DMA engine can't transfer the bytes out
to rx DMA buffer. so it need a way to fetch them out and
flush them into tty buffer in time.

in the above case, we want UART switch from DMA mode to PIO mode and
fetch && flush bytes into tty layer buffer until rxfifo become empty,
after that done let UART switch from PIO mode back to DMA mode.
(record as method1)

method1 result in the next receive result wrong. for example in PIO part
of method1, we fetched && pushed X1...X3 bytes, when UART rxfifo newly
received Y1...Y4 bytes, UART trigger a DMA unit transfer, the DMA unit's
content is X1...X3Y1 and rxfifo fifo status is empty, so X1X2X3 pushed
twice by PIO way and DMA way also the bytes Y2Y3Y4 missed. add rxfifo
reset operation before UART switch back to DMA mode would resolve the
issue. ([method1 + do fifo reset] record as method2)

before the commit, UART driver use method2. but methd2 have a risk of
data loss, as if UART's shift register receive a complete byte and
transfer it into rxfifo before rxfifo reset operation the byte will
loss.

UART and USP have the similar bits CLEAR_RX_ADDR_EN(uart)/FRADDR_CLR_EN(usp),
When found UART controller changing I/O to DMA mode, UART controller
clears the two low bits of read point (rx_fifo_addr[1:0]).
when enable the bit + method1(record as method3), in above example
the DMA unit's content is X1...X3Y1 and there are Y2Y3Y4 in rxfifo by
experiment, we just push bytes in rx DMA buffer.

BTW, the workaround works only for UART receive DMA channel use SINGLE
DMA mode.
Signed-off-by: NQipan Li <Qipan.Li@csr.com>
Signed-off-by: NBarry Song <Baohua.Song@csr.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The implementation of cris_console_device() is exactly the same as
uart_console_device(), so let's switch to use uart_console_device().
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Acked-by: NNiklas Cassel <nks@flawful.org>
Acked-by: NJesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

OMAP h/w-assisted IXON flow control is borked. The transmitter becomes
stuck if XON is never received; clearing the fifos or resetting the
rx flow control bits has no effect.

Remove auto-IXANY as well, since without auto-IXON, it has no purpose.
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Due to Advisory 21 as documented in AM437x errata document,
UART module cannot be disabled once DMA is used. The only
workaround is to softreset the module before disabling it.

DRA7x UARTs are compatible to AM437x UARTs in terms of
this errata and prescribed workaround.

Enable usage of workaround for this errata on DRA7x SoCs.
Signed-off-by: NSekhar Nori <nsekhar@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

AM335x, AM437x and DRA7x SoCs have an errata[1] due to which UART
cannot be idled after it has been used with DMA.

OMAP3 has a similar sounding errata which has been worked around
in a2fc3661 ("ARM: OMAP3: Use manual idle for UARTs
because of DMA errata"). But the workaround used there does not
apply to AM335x, AM437x SoCs.

After using DMA, the UART module on these SoCs must be soft reset
to go to idle.

This patch implements that errata workaround. It is expected that
UART will be used with DMA so no explicit check for DMA usage
has been added for errata applicability.

MDR1 register needs to be restored right after soft-reset because
"UART mode" must be set in that register for module wake-up on AM335x
to work. As a result, SCR register is now used to determine if
context was lost during sleep.

[1] See Advisory 21 in AM437x errata SPRZ408B, updated April 2015.
    http://www.ti.com/lit/er/sprz408b/sprz408b.pdfSigned-off-by: NSekhar Nori <nsekhar@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use of of_machine_is_compatible() for handling AM335x specific
"DMA kick" quirk in 8250_omap driver makes it ugly to extend the
quirk for other platforms. Instead use a new compatible.

The new compatible will also make it easier to take care of
other quirks on AM335x and like SoCs.

In order to not break backward DTB compatibility for users of
8250_omap driver on AM335x based boards, existing use of
of_machine_is_compatible() has not been removed.
Signed-off-by: NSekhar Nori <nsekhar@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The silicon errata[1] workaround implemented in a follow-on
patch, "serial: 8250_omap: workaround errata on disabling
UART after using DMA", requires MDR1 register programming.

Extract MDR1 register update into helper function,
omap8250_update_mdr1() to help with that.

[1] Advisory 21 in http://www.ti.com/lit/er/sprz408b/sprz408b.pdfSigned-off-by: NSekhar Nori <nsekhar@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

omap_device infrastructure has a suspend_noirq hook which
runtime suspends all devices late in the suspend cycle (see
_od_suspend_noirq() in arch/arm/mach-omap2/omap_device.c)

This leads to a NULL pointer exception in 8250_omap driver
since by the time omap8250_runtime_suspend() is called, 8250_dma
driver has already set rxchan to NULL via serial8250_release_dma().

Make an explicit check to see if rxchan is NULL in
runtime_{suspend|resume} hooks to fix this.
Signed-off-by: NSekhar Nori <nsekhar@ti.com>
Acked-by: NTony Lindgren <tony@atomide.com>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fintek chip can be configured for io addresses different than the standard.

Query the chip for the configured addresses and try to match it with the
pnp address.
Reported-by: NPeter Hong <peter_hong@fintek.com.tw>
Reviewed-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Chip can be configured to use entry key different than 0x77. Try all the
valid keys until one gives out the right chip id.
Reported-by: NPeter Hong <peter_hong@fintek.com.tw>
Reviewed-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There are some chips with the same interface but different chip ip.
Reported-by: NPeter Hong <peter_hong@fintek.com.tw>
Reviewed-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fintek chip can be connected at address 0x4e and also 0x2e.
Add some logic to find out the address of the chip.
Reported-by: NPeter Hong <peter_hong@fintek.com.tw>
Reviewed-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Save the port index and the line id in a private structure.
Reported-by: NPeter Hong <peter_hong@fintek.com.tw>
Reviewed-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NRicardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In little endian cases, macro htons unfolds to __swab16 which
provides special case for constants. In big endian cases,
__constant_htons and htons expand directly to the same expression.
So, replace __constant_htons with htons with the goal of getting
rid of the definition of __constant_htons completely.

The semantic patch that performs this transformation is as follows:

@@expression x;@@

- __constant_htons(x)
+ htons(x)
Signed-off-by: NVaishali Thakkar <vthakkar1994@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Switch to my kernel.org alias instead of a badly named gmail address,
which I rarely use.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Some modules call config_item_init_type_name() and config_group_init_type_name()
with parameter "name" directly controlled by userspace.  These two
functions call config_item_set_name() with this name used as a format
string, which can be used to leak information such as content of the
stack to userspace.

For example, make_netconsole_target() in netconsole module calls
config_item_init_type_name() with the name of a newly-created directory.
This means that the following commands give some unexpected output, with
configfs mounted in /sys/kernel/config/ and on a system with a
configured eth0 ethernet interface:

    # modprobe netconsole
    # mkdir /sys/kernel/config/netconsole/target_%lx
    # echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name
    # echo 1 > /sys/kernel/config/netconsole/target_%lx/enabled
    # echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name
    # dmesg |tail -n1
    [  142.697668] netconsole: target (target_ffffffffc0ae8080) is
    enabled, disable to update parameters

The directory name is correct but %lx has been interpreted in the
internal item name, displayed here in the error message used by
store_dev_name() in drivers/net/netconsole.c.

To fix this, update every caller of config_item_set_name to use "%s"
when operating on untrusted input.

This issue was found using -Wformat-security gcc flag, once a __printf
attribute has been added to config_item_set_name().
Signed-off-by: NNicolas Iooss <nicolas.iooss_linux@m4x.org>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NFelipe Balbi <balbi@ti.com>
Acked-by: NJoel Becker <jlbec@evilplan.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove the 'flags' variable in order to fix the following warning:

drivers/rtc/rtc-armada38x.c:91:22: warning: unused variable 'flags' [-Wunused-variable]
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

rtc_sysfs_add_device checks if device can wakeup before creating the
wakealarm file in sysfs. Thus the driver must set wakeup capability
before registering the rtc device.
Signed-off-by: NWei-Ning Huang <wnhuang@google.com>
Acked-by: NEddie Huang <eddie.huang@mediatek.com>
Signed-off-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>

The GICv3 ITS architecture allows a given [DevID, EventID] pair to be
translated to a [LPI, Collection] pair, where DevID is the device writing
the MSI, EventID is the payload being written, LPI is the actual
interrupt number, and Collection is roughly equivalent to a target CPU.

Each LPI can be mapped to a separate collection, but the ITS driver
insists on maintaining the collection on a device basis, instead of doing
it on a per interrupt basis.

This is obviously flawed, and this patch fixes it by adding a per interrupt
index that indicates which collection number is in use.
Reported-by: NIan Campbell <ian.campbell@citrix.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: stable@vger.kernel.org	# 4.1, 4.0
Link: http://lkml.kernel.org/r/1437126402-11677-1-git-send-email-marc.zyngier@arm.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>

Calls to set_memory_wb() incure heavy TLB flush and IPI cost. To
minimize those wait until pool grow beyond batch size before
draining the pool.
Signed-off-by: NJérôme Glisse <jglisse@redhat.com>
Reviewed-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-and-Tested-by: NMichel Dänzer <michel@daenzer.net>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

Current code never allowed the page pool to actualy fill in anyway.
This fix it, so that we only start freeing page from the pool when
we go over the pool size.

Changed since v1:
  - Move the page batching optimization to its separate patch.

Changed since v2:
  - Do not remove code part of the batching optimization with
    this patch.
  - Better commit message.
Signed-off-by: NJérôme Glisse <jglisse@redhat.com>
Reviewed-by: NMario Kleiner <mario.kleiner.de@gmail.com>
Reviewed-and-Tested-by: NMichel Dänzer <michel.daenzer@amd.com>
Reviewed-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDave Airlie <airlied@redhat.com>

If no work was performed then prealloc_data_structs() wasn't ever called
so there isn't any need to call prealloc_free_structs().
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Refactor writeback_some_dirty_blocks() to avoid prealloc_data_structs()
if the policy doesn't have any dirty blocks ready for writeback.
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

All methods that queue work call wake_worker() as you'd expect.
E.g. cell_defer, defer_bio, quiesce_migration (which is called by
writeback, promote, demote_then_promote, invalidate, discard, etc).
Signed-off-by: NMike Snitzer <snitzer@redhat.com>

Something (ATOM BIOS?) seems to be clobbering the LB_INTERRUPT_MASK
register while the CRTC is off, which caused e.g. glxgears or
gnome-shell to hang after a modeset.
Signed-off-by: NMichel Dänzer <michel.daenzer@amd.com>
Reviewed-by: NJammy Zhou <Jammy.Zhou@amd.com>

This has been a source of confusion.  Make it debug only.
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

Reviewed-by: NJammy Zhou <Jammy.Zhou@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

So the selected forced level shows up properly in sysfs.
Reviewed-by: NJammy Zhou <Jammy.Zhou@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

This is necessary to properly reset the min/max limits before
clamping them otherwise we may get improper clamping depending
on what what was the last forced level.
Reviewed-by: NJammy Zhou <Jammy.Zhou@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

Always respect the harvest configuration as is.
Acked-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

v2: squash in later fix
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

If we run into a part with a harvest configuration where the entire
IP block is unusable, just disable the IP block.

v2: fix logic as noted by Christian
Reviewed-by: NChristian König <christian.koenig@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>