Add the suspend and resume handlers for the versal uart platform driver.
Adds the suspend for sbsa driver.
Sbsa is a subset of the pl011 driver.
Signed-off-by: NShubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1575873048-14313-1-git-send-email-shubhrajyoti.datta@gmail.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Fix the following warning:
drivers/tty/serial/amba-pl011.c: In function check_apply_cts_event_workaround:
drivers/tty/serial/amba-pl011.c:1461:15: warning: variable dummy_read set but not used [-Wunused-but-set-variable]

The data read is useless and can be dropped.
Reported-by: NHulk Robot <hulkci@huawei.com>
Signed-off-by: NXiongfeng Wang <wangxiongfeng2@huawei.com>
Link: https://lore.kernel.org/r/1575619526-34482-1-git-send-email-wangxiongfeng2@huawei.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

PL011's ->flush_buffer() implementation releases and reacquires the port
lock.  Due to a race condition here, data can end up being added to the
circular buffer but neither being discarded nor being sent out.  This
leads to, for example, tcdrain(2) waiting indefinitely.

Process A                       Process B

uart_flush_buffer()
 - acquire lock
 - circ_clear
 - pl011_flush_buffer()
 -- release lock
 -- dmaengine_terminate_all()

                                uart_write()
                                - acquire lock
                                - add chars to circ buffer
                                - start_tx()
                                -- start DMA
                                - release lock

 -- acquire lock
 -- turn off DMA
 -- release lock

                                // Data in circ buffer but DMA is off

According to the comment in the code, the releasing of the lock around
dmaengine_terminate_all() is to avoid a deadlock with the DMA engine
callback.  However, since the time this code was written, the DMA engine
API documentation seems to have been clarified to say that
dmaengine_terminate_all() (in the identically implemented but
differently named dmaengine_terminate_async() variant) does not wait for
any running complete callback to be completed and can even be called
from a complete callback.  So there is no possibility of deadlock if the
DMA engine driver implements this API correctly.

So we should be able to just remove this release and reacquire of the
lock to prevent the aforementioned race condition.
Signed-off-by: NVincent Whitchurch <vincent.whitchurch@axis.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20191118092547.32135-1-vincent.whitchurch@axis.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

dma_request_slave_channel_reason() is:
#define dma_request_slave_channel_reason(dev, name) \
	dma_request_chan(dev, name)
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Link: https://lore.kernel.org/r/20191113094618.1725-2-peter.ujfalusi@ti.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

pl011_dma_probe() is only used in pl011_dma_startup() which does only
exist when CONFIG_DMA_ENGINE=y, so remove the unused dummy version to
silence the warning.
Signed-off-by: NQian Cai <cai@lca.pw>
Link: https://lore.kernel.org/r/1568726340-4518-1-git-send-email-cai@lca.pwSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We don't need dev_err() messages when platform_get_irq() fails now that
platform_get_irq() prints an error message itself when something goes
wrong. Let's remove these prints with a simple semantic patch.

// <smpl>
@@
expression ret;
struct platform_device *E;
@@

ret =
(
platform_get_irq(E, ...)
|
platform_get_irq_byname(E, ...)
);

if ( \( ret < 0 \| ret <= 0 \) )
{
(
-if (ret != -EPROBE_DEFER)
-{ ...
-dev_err(...);
-... }
|
...
-dev_err(...);
)
...
}
// </smpl>

While we're here, remove braces on if statements that only have one
statement (manually).

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NStephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190730181557.90391-45-swboyd@chromium.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The PL011 register space includes all necessary status bits to
determine whether a device instance requires handling in response
to an interrupt. Therefore, multiple instances of the device could
be serviced by a single shared interrupt, which is the case on BCM7211.
Signed-off-by: NDoug Berger <opendmb@gmail.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When the test 'CONFIG_DEBUG_TEST_DRIVER_REMOVE=y' is enabled,
arch_initcall(pl011_init) came before subsys_initcall(default_bdi_init).
devtmpfs gets killed because we try to remove a file and decrement the
wb reference count before the noop_backing_device_info gets initialized.

[    0.332075] Serial: AMBA PL011 UART driver
[    0.485276] 9000000.pl011: ttyAMA0 at MMIO 0x9000000 (irq = 39, base_baud = 0) is a PL011 rev1
[    0.502382] console [ttyAMA0] enabled
[    0.515710] Unable to handle kernel paging request at virtual address 0000800074c12000
[    0.516053] Mem abort info:
[    0.516222]   ESR = 0x96000004
[    0.516417]   Exception class = DABT (current EL), IL = 32 bits
[    0.516641]   SET = 0, FnV = 0
[    0.516826]   EA = 0, S1PTW = 0
[    0.516984] Data abort info:
[    0.517149]   ISV = 0, ISS = 0x00000004
[    0.517339]   CM = 0, WnR = 0
[    0.517553] [0000800074c12000] user address but active_mm is swapper
[    0.517928] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[    0.518305] Modules linked in:
[    0.518839] CPU: 0 PID: 13 Comm: kdevtmpfs Not tainted 4.19.0-rc5-next-20180928-00002-g2ba39ab0cd01-dirty #82
[    0.519307] Hardware name: linux,dummy-virt (DT)
[    0.519681] pstate: 80000005 (Nzcv daif -PAN -UAO)
[    0.519959] pc : __destroy_inode+0x94/0x2a8
[    0.520212] lr : __destroy_inode+0x78/0x2a8
[    0.520401] sp : ffff0000098c3b20
[    0.520590] x29: ffff0000098c3b20 x28: 00000000087a3714
[    0.520904] x27: 0000000000002000 x26: 0000000000002000
[    0.521179] x25: ffff000009583000 x24: 0000000000000000
[    0.521467] x23: ffff80007bb52000 x22: ffff80007bbaa7c0
[    0.521737] x21: ffff0000093f9338 x20: 0000000000000000
[    0.522033] x19: ffff80007bbb05d8 x18: 0000000000000400
[    0.522376] x17: 0000000000000000 x16: 0000000000000000
[    0.522727] x15: 0000000000000400 x14: 0000000000000400
[    0.523068] x13: 0000000000000001 x12: 0000000000000001
[    0.523421] x11: 0000000000000000 x10: 0000000000000970
[    0.523749] x9 : ffff0000098c3a60 x8 : ffff80007bbab190
[    0.524017] x7 : ffff80007bbaa880 x6 : 0000000000000c88
[    0.524305] x5 : ffff0000093d96c8 x4 : 61c8864680b583eb
[    0.524567] x3 : ffff0000093d6180 x2 : ffffffffffffffff
[    0.524872] x1 : 0000800074c12000 x0 : 0000800074c12000
[    0.525207] Process kdevtmpfs (pid: 13, stack limit = 0x(____ptrval____))
[    0.525529] Call trace:
[    0.525806]  __destroy_inode+0x94/0x2a8
[    0.526108]  destroy_inode+0x34/0x88
[    0.526370]  evict+0x144/0x1c8
[    0.526636]  iput+0x184/0x230
[    0.526871]  dentry_unlink_inode+0x118/0x130
[    0.527152]  d_delete+0xd8/0xe0
[    0.527420]  vfs_unlink+0x240/0x270
[    0.527665]  handle_remove+0x1d8/0x330
[    0.527875]  devtmpfsd+0x138/0x1c8
[    0.528085]  kthread+0x14c/0x158
[    0.528291]  ret_from_fork+0x10/0x18
[    0.528720] Code: 92800002 aa1403e0 d538d081 8b010000 (c85f7c04)
[    0.529367] ---[ end trace 5a3dee47727f877c ]---

Rework to set suppress_bind_attrs flag to avoid removing the device when
CONFIG_DEBUG_TEST_DRIVER_REMOVE=y. This applies for pic32_uart and
xilinx_uartps as well.
Co-developed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 9b96fbac ("serial: PL011: clear pending interrupts")
clears the RX and receive timeout interrupts on pl011 startup, to
avoid a screaming-interrupt scenario that can occur when the
firmware or bootloader leaves these interrupts asserted.

This has been noted as an issue when running Linux on qemu [1].

Unfortunately, the above fix seems to lead to potential
misbehaviour if the RX FIFO interrupt is asserted _non_ spuriously
on driver startup, if the RX FIFO is also already full to the
trigger level.

Clearing the RX FIFO interrupt does not change the FIFO fill level.
In this scenario, because the interrupt is now clear and because
the FIFO is already full to the trigger level, no new assertion of
the RX FIFO interrupt can occur unless the FIFO is drained back
below the trigger level.  This never occurs because the pl011
driver is waiting for an RX FIFO interrupt to tell it that there is
something to read, and does not read the FIFO at all until that
interrupt occurs.

Thus, simply clearing "spurious" interrupts on startup may be
misguided, since there is no way to be sure that the interrupts are
truly spurious, and things can go wrong if they are not.

This patch instead clears the interrupt condition by draining the
RX FIFO during UART startup, after clearing any potentially
spurious interrupt.  This should ensure that an interrupt will
definitely be asserted if the RX FIFO subsequently becomes
sufficiently full.

The drain is done at the point of enabling interrupts only.  This
means that it will occur any time the UART is newly opened through
the tty layer.  It will not apply to polled-mode use of the UART by
kgdboc: since that scenario cannot use interrupts by design, this
should not matter.  kgdboc will interact badly with "normal" use of
the UART in any case: this patch makes no attempt to paper over
such issues.

This patch does not attempt to address the case where the RX FIFO
fills faster than it can be drained: that is a pathological
hardware design problem that is beyond the scope of the driver to
work around.  As a failsafe, the number of poll iterations for
draining the FIFO is limited to twice the FIFO size.  This will
ensure that the kernel at least boots even if it is impossible to
drain the FIFO for some reason.

[1] [Qemu-devel] [Qemu-arm] [PATCH] pl011: do not put into fifo
before enabled the interruption
https://lists.gnu.org/archive/html/qemu-devel/2018-01/msg06446.htmlReported-by: NWei Xu <xuwei5@hisilicon.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Fixes: 9b96fbac ("serial: PL011: clear pending interrupts")
Signed-off-by: NDave Martin <Dave.Martin@arm.com>
Cc: stable <stable@vger.kernel.org>
Tested-by: NWei Xu <xuwei5@hisilicon.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 075167ed ("drivers: PL011: replace UART_MIS reading with
_RIS & _IMSC") amended this driver's interrupt handler to read the
Raw Interrupt Status (RIS) and Interrupt Mask Set/Clear (IMSC) registers
instead of the Masked Interrupt Status (MIS) register.  The change was
made to attain compatibility with SBSA UARTs which lack the MIS register.

However the IMSC register is cached by the driver.  Using the cached
copy saves one register read per interrupt.

I've tested this change successfully on a BCM2837 (Raspberry Pi CM3).

Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Phil Elwell <phil@raspberrypi.org>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Mark Langsdorf <mlangsdo@redhat.com>
Cc: Naresh Bhat <nbhat@cavium.com>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

pl011_fifo_to_tty() has two counters (max_count and fifotaken) for the
same loop.  One counter should suffice.  This saves one subtraction per
character read from the RX FIFO.

Cc: Mathias Duckeck <m.duckeck@kunbus.de>
Cc: Phil Elwell <phil@raspberrypi.org>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that the SPDX tag is in all tty files, that identifies the license
in a specific and legally-defined manner.  So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Jiri Slaby <jslaby@suse.com>
Cc: Eric Anholt <eric@anholt.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Joachim Eastwood <manabian@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: Pat Gefre <pfg@sgi.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: David Brown <david.brown@linaro.org>
Cc: "Andreas Färber" <afaerber@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Timur Tabi <timur@tabi.org>
Cc: Tony Prisk <linux@prisktech.co.nz>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/tty files files with the correct SPDX license
identifier based on the license text in the file itself.  The SPDX
identifier is a legally binding shorthand, which can be used instead of
the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Jiri Slaby <jslaby@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: David Sterba <dsterba@suse.com>
Cc: James Hogan <jhogan@kernel.org>
Cc: Rob Herring <robh@kernel.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list@broadcom.com
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Joachim Eastwood <manabian@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Tobias Klauser <tklauser@distanz.ch>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Richard Genoud <richard.genoud@gmail.com>
Cc: Alexander Shiyan <shc_work@mail.ru>
Cc: Baruch Siach <baruch@tkos.co.il>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Cc: "Uwe Kleine-König" <kernel@pengutronix.de>
Cc: Pat Gefre <pfg@sgi.com>
Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: Sylvain Lemieux <slemieux.tyco@gmail.com>
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Andy Gross <andy.gross@linaro.org>
Cc: David Brown <david.brown@linaro.org>
Cc: "Andreas Färber" <afaerber@suse.de>
Cc: Kevin Cernekee <cernekee@gmail.com>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Timur Tabi <timur@tabi.org>
Cc: Tony Prisk <linux@prisktech.co.nz>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Back in 2010, commit 3b43816f ("ARM: 5933/1: amba-pl011: support
hardware flow control") added an autorts flag to this driver to store
whether automatic hardware flow control is requested.

In 2015, commit 391f93f2 ("serial: core: Rework hw-assisted flow
control support") added a flag with identical functionality to generic
code.

Switch over to that flag and drop the driver-specific one.

Cc: Rabin Vincent <rabin.vincent@stericsson.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: NLukas Wunner <lukas@wunner.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

In preparation for unconditionally passing the struct timer_list pointer to
all timer callbacks, switch to using the new timer_setup() and from_timer()
to pass the timer pointer explicitly.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

amba_id are not supposed to change at runtime. All functions
working with const amba_id. So mark the non-const structs as const.
Signed-off-by: NArvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

These vendor_data structures are only stored in the vendor field of
the uart_amba_port structure, as defined in the same file, and this
field is declared as const.  Thus the vendor_data structures can be
const too.

Done with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The work-around for Qualcomm Technologies QDF2400 Erratum 44 hinges on a
global variable defined in the pl011 driver.  The ACPI SPCR parsing code
determines whether the work-around is needed, and if so, it changes the
console name from "pl011" to "qdf2400_e44".  The expectation is that
the pl011 driver will implement the work-around when it sees the console
name.  The global variable qdf2400_e44_present is set when that happens.

The problem is that work-around needs to be enabled when the pl011
driver probes, not when the console name is queried.  However, sbsa_probe()
is called before pl011_console_match().  The work-around appeared to work
previously because the default console on QDF2400 platforms was always
ttyAMA1.  The first time sbsa_probe() is called (for ttyAMA0),
qdf2400_e44_present is still false.  Then pl011_console_match() is called,
and it sets qdf2400_e44_present to true.  All subsequent calls to
sbsa_probe() enable the work-around.

The solution is to move the global variable into spcr.c and let the
pl011 driver query it during probe time.  This works because all QDF2400
platforms require SPCR, so parse_spcr() will always be called.
pl011_console_match still checks for the "qdf2400_e44" console name,
but it doesn't do anything else special.

Fixes: 5a0722b8 ("tty: pl011: use "qdf2400_e44" as the earlycon name for QDF2400 E44")
Tested-by: NJeffrey Hugo <jhugo@codeaurora.org>
Signed-off-by: NTimur Tabi <timur@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Define a new early console name for Qualcomm Datacenter Technologies
QDF2400 SOCs affected by erratum 44, instead of piggy-backing on "pl011".
Previously, to enable traditional (non-SPCR) earlycon, the documentation
said to specify "earlycon=pl011,<address>,qdf2400_e44", but the code was
broken and this didn't actually work.

So instead, the method for specifying the E44 work-around with traditional
earlycon is "earlycon=qdf2400_e44,<address>".  Both methods of earlycon
are now enabled with the same function.

Fixes: e53e597f ("tty: pl011: fix earlycon work-around for QDF2400 erratum 44")
Signed-off-by: NTimur Tabi <timur@codeaurora.org>
Cc: stable <stable@vger.kernel.org> # 4.11
Tested-by: NShanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On SMP systems, we see a lot of spurious TX interrupts when a
program generates a steady stream of output to the pl011 UART.

The problem can be easily seen when one CPU generates the output
while another CPU handles the pl011 interrupts, and the rate of
output is low enough not to fill the TX FIFO. The problem seems
to be:

    -- CPU a --                        -- CPU b --
   (take port lock)
   pl011_start_tx
      pl011_start_tx_pio
         enable TXIM in REG_IMSC   ->  causes uart tx intr (pl011_int)
         pl011_tx_chars                pl011_int
            ...tx chars, all done...       (wait for port lock)
            pl011_stop_tx                   .
               disable TXIM                 .
    (release port lock)            ->      (take port lock)
                                           check for TXIM, not enabled
                                           (release port lock)
                                           return IRQ_NONE

Enabling the TXIM in pl011_start_tx_pio() causes the interrupt
to be generated and delivered to CPU b, even though pl011_tx_chars()
is able to complete the TX and then disable the tx interrupt.

Fix this by enabling TXIM only after pl011_tx_chars, if it is needed.
pl011_tx_chars will return a boolean indicating whether the TX
interrupts have to be enabled.
Debugged-by: NVijaya Kumar <Vijaya.Kumar@cavium.com>
Signed-off-by: NJayachandran C <jnair@caviumnetworks.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The work-around for the Qualcomm Datacenter Technologies QDF2400
erratum 44 sets the "qdf2400_e44_present" global variable if the
work-around is needed.  However, this check does not happen until after
earlycon is initialized, which means the work-around is not
used, and the console hangs as soon as it displays one character.

Fixes: d8a4995b ("tty: pl011: Work around QDF2400 E44 stuck BUSY bit")
Signed-off-by: NTimur Tabi <timur@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The original patch makes the condition always true, so it is wrong.

It masks (but not fixes) the bug described in the commit message
but introduces a regression (no console is selected by SPCR)
in regular (no 'console=ttyAMA') case.

s/||/&&/ would not fix the problem as the root cause was identified
incorrectly.

This reverts commit aea9a80b.
Signed-off-by: NAleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NSudeep Holla <sudeep.holla@arm.com>
Tested-by: NJayachandran C <jnair@caviumnetworks.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The original patch makes the condition always true, so it is wrong.

It masks (but not fixes) the bug described in the commit message
but introduces a regression (no console is selected by SPCR)
in regular (no 'console=ttyAMA') case.

s/||/&&/ would not fix the problem as the root cause was identified
incorrectly.

This reverts commit aea9a80b.
Signed-off-by: NAleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Qualcomm Datacenter Technologies QDF2400 family of SoCs contains a
custom (non-PrimeCell) implementation of the SBSA UART. Occasionally the
BUSY bit in the Flag Register gets stuck as 1, erratum 44 for both 2432v1
and 2400v1 SoCs.Checking that the Transmit FIFO Empty (TXFE) bit is 0,
instead of checking that the BUSY bit is 1, works around the issue.

To facilitate this substitution of flags and values, introduce
vendor-specific inversion of Feature Register bits when UART AMBA Port
(UAP) data is available. For the earlycon case, prior to UAP availability,
implement alternative putc and early_write functions.

Similar to what how ARMv8 ACPI PCI quirks are detected during MCFG parsing,
check the OEM fields of the Serial Port Console Redirection (SPCR) ACPI
table to determine if the current platform is known to be affected by the
erratum.
Signed-off-by: NChristopher Covington <cov@codeaurora.org>
Acked-by: NRussell King <rmk+kernel@armlinux.org.uk>
Acked-by: NTimur Tabi <timur@codeaurora.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit c7cef0a8 ("console: Add extensible console matching") added
match() method to struct console which allows the console to perform
console command line matching instead of (or in addition to) default
console matching (ie., by fixed name and index).

Commit ad1696f6 ("ACPI: parse SPCR and enable matching console")
introduced support for SPCR as matching console.

Commit 10879ae5 ("serial: pl011: add console matching function")
added the match method for pl011 console which checks for the console
string to be "pl011"

Now on a platform which has both SPCR in the ACPI tables and ttyAMA in
the command line, the ttyAMA is chosen as "selected console" but it
doesn't pass the matching console method which results in CON_CONSDEV
not being set on the "selected console".

As a result of that, the bootconsole(SPCR in the above case) is not
unregistered and all the beginning boot messages are seen twice.

This patch adds "ttyAMA" so that it's considered to match pl011 console.

Fixes: 10879ae5 ("serial: pl011: add console matching function")
Cc: Russell King <linux@armlinux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Aleksey Makarov <aleksey.makarov@linaro.org>
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Declare uart_ops structures as const as they are only stored in the ops
field of an uart_port structure. This field is of type const, so
uart_ops structures having this property can be made const too.

File size details before and after patching.
First line of every .o file shows the file size before patching
and second line shows the size after patching.

   text	   data	    bss	    dec	    hex	filename

   2977	    456	     64	   3497	    da9	drivers/tty/serial/amba-pl010.o
   3169	    272	     64	   3505	    db1	drivers/tty/serial/amba-pl010.o

   3109	    456	      0	   3565	    ded	drivers/tty/serial/efm32-uart.o
   3301	    272	      0	   3573	    df5	drivers/tty/serial/efm32-uart.o

  10668	    753	      1	  11422	   2c9e	drivers/tty/serial/icom.o
  10860	    561	      1	  11422	   2c9e	drivers/tty/serial/icom.o

  23904	    408	      8	  24320	   5f00	drivers/tty/serial/ioc3_serial.o
  24088	    224	      8	  24320	   5f00	drivers/tty/serial/ioc3_serial.o

  10516	    560	      4	  11080	   2b48	drivers/tty/serial/ioc4_serial.o
  10709	    368	      4	  11081	   2b49	drivers/tty/serial/ioc4_serial.o

   7853	    648	   1216	   9717	   25f5	drivers/tty/serial/mpsc.o
   8037	    456	   1216	   9709	   25ed	drivers/tty/serial/mpsc.o

  10248	    456	      0	  10704	   29d0	drivers/tty/serial/omap-serial.o
  10440	    272	      0	  10712	   29d8	drivers/tty/serial/omap-serial.o

   8122	    532	   1984	  10638	   298e	drivers/tty/serial/pmac_zilog.o
   8306	    340	   1984	  10630	   2986	drivers/tty/serial/pmac_zilog.o

   3808	    456	      0	   4264	   10a8	drivers/tty/serial/pxa.o
   4000	    264	      0	   4264	   10a8	drivers/tty/serial/pxa.o

  21781	   3864	      0	  25645	   642d	drivers/tty/serial/serial-tegra.o
  22037	   3608	      0	  25645	   642d	drivers/tty/serial/serial-tegra.o

   2481	    456	     96	   3033	    bd9	drivers/tty/serial/sprd_serial.o
   2673	    272	     96	   3041	    be1	drivers/tty/serial/sprd_serial.o

   5534	    300	    512	   6346	   18ca	drivers/tty/serial/vr41xx_siu.o
   5630	    204	    512	   6346	   18ca	drivers/tty/serial/vr41xx_siu.o

   6730	   1576	    128	   8434	   20f2	drivers/tty/serial/vt8500_serial.o
   6986	   1320	    128	   8434	   20f2	drivers/tty/serial/vt8500_serial.o

Cross compiled for mips architecture.

   3005	    488	      0	   3493	    da5	drivers/tty/serial/pnx8xxx_uart.o
   3189	    304	      0	   3493	    da5	drivers/tty/serial/pnx8xxx_uart.o

   4272	    196	   1056	   5524	   1594	drivers/tty/serial/dz.o
   4368	    100	   1056	   5524	   1594	drivers/tty/serial/dz.o

   6551	    144	     16	   6711	   1a37	drivers/tty/serial/ip22zilog.o
   6647	     48	     16	   6711	   1a37	drivers/tty/serial/ip22zilog.o

   9612	    428	   1520	  11560	   2d28	drivers/tty/serial/serial_txx9.o
   9708	    332	   1520	  11560	   2d28	drivers/tty/serial/serial_txx9.o

   4156	    296	     16	   4468	   1174	drivers/tty/serial/ar933x_uart.o
   4252	    200	     16	   4468	   1174	drivers/tty/serial/ar933x_uart.o

Cross compiled for arm archiecture.

  11716	   1780	     44	  13540	   34e4	drivers/tty/serial/sirfsoc_uart.o
  11808	   1688	     44	  13540	   34e4	drivers/tty/serial/sirfsoc_uart.o

  13352	    596	     56	  14004	   36b4	drivers/tty/serial/amba-pl011.o
  13444	    504	     56	  14004	   36b4	drivers/tty/serial/amba-pl011.o

Cross compiled for sparc architecture.

   4664	    528	     32	   5224	   1468	drivers/tty/serial/sunhv.o
   4848	    344	     32	   5224	   1468	drivers/tty/serial/sunhv.o

   8080	    332	     28	   8440	   20f8	drivers/tty/serial/sunzilog.o
   8184	    228	     28	   8440	   20f8	drivers/tty/serial/sunzilog.o

Cross compiled for ia64 architecture.

  10226	    549	    472	  11247	   2bef	drivers/tty/serial/sn_console.o
  10414	    365	    472	  11251	   2bf3	drivers/tty/serial/sn_console.o

The files drivers/tty/serial/zs.o, drivers/tty/serial/lpc32xx_hs.o and
drivers/tty/serial/lantiq.o did not compile.
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Exactly as in a80c49db ("serial8250: Mark console as CON_ANYTIME"),
to enable printk() during CPU hot-plugging.

Actually most of the serial console drivers do not use per-cpu resources
and can be marked as CON_ANYTIME.
Signed-off-by: NAlexander Sverdlin <alexander.sverdlin@nokia.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: linux-serial@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Declare an OF early console for SBSA UART so that the early console device
can be specified via the "stdout-path" property in device-tree.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds function pl011_console_match() that implements
method match of struct console.  It allows to match consoles against
data specified in a string, for example taken from command line or
compiled by ACPI SPCR table handler.

This patch was merged to tty-next but then reverted because of
conflict with

commit 46e36683 ("serial: earlycon: Extend earlycon command line option to support 64-bit addresses")

Now it is fixed.
Signed-off-by: NAleksey Makarov <aleksey.makarov@linaro.org>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Acked-by: NRussell King <rmk+kernel@armlinux.org.uk>
Tested-by: NChristopher Covington <cov@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit 8b8f347d as it
causes build errors in linux-next
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Cc: Aleksey Makarov <aleksey.makarov@linaro.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Cc: Christopher Covington <cov@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch adds function pl011_console_match() that implements
method match of struct console.  It allows to match consoles against
data specified in a string, for example taken from command line or
compiled by ACPI SPCR table handler.
Signed-off-by: NAleksey Makarov <aleksey.makarov@linaro.org>
Reviewed-by: NPeter Hurley <peter@hurleysoftware.com>
Acked-by: NRussell King <rmk+kernel@armlinux.org.uk>
Tested-by: NChristopher Covington <cov@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Don't complain on -EPROBE_DEFER when attempting to get the irq.
the driver probe will be retried later.

Cc: Russell King <linux@armlinux.org.uk>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NKefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Commit 0e125a5f ("tty: amba-pl011: define flag register bits for ZTE
device") changes earlycon function pl011_putc() to use a pointer to
uart_amba_port.  This causes a regression when earlycon is enabled,
because uart_amba_port is not available yet at earlycon time.  Let's
revert the change on pl011_putc() to fix the regression.

The earlycon support for ZTE device can probably be added later by
declaring a new earlycon setup function with a vendor specific
compatible.
Reported-by: NSudeep Holla <sudeep.holla@arm.com>
Fixes: 0e125a5f ("tty: amba-pl011: define flag register bits for ZTE device")
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Tested-by: NSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is no Peripheral Identification Registers on ZTE PL011 device, so
although the driver amba-pl011 is ready to work for ZTE device, the
device cannot be probed by the driver at all.

With arm,primecell-periphid DT bindings (bindings/arm/primecell.txt) in
place, it should be the cleanest the way to use a pseudo-ID to probe the
device from AMBA bus.  We create an unofficial vendor number
AMBA_VENDOR_LINUX, which will practically never become an official
vendor ID, and takes Configuration, Revision number, and Part number as
input to compose a pseudo-ID for ZTE device.

Also, since we start using vendor_zte to probe ZTE device, the
__maybe_unused for vendor_zte is removed.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

ZTE PL011 device has a fixed FIFO size 16.  Let's add a .get_fifosize
hook for it.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

For some reason we do not really understand, ZTE hardware designers
choose to define PL011 Flag Register bit positions differently from
standard ones as below.

	Bit		Standard	ZTE
	-----------------------------------
	CTS		0		1
	DSR		1		3
	BUSY		3		8
	RI		8		0

Let's define these bits into vendor data and get ZTE PL011 supported
properly.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Acked-by: NRussell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

platform_get_irq can fail, so we should handle negative value when
returned.

[v2]

platform_get_irq can actually return zero on some platforms. So do not
remove checks for irq == 0 there.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "Uwe Kleine-König" <kernel@pengutronix.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Laxman Dewangan <ldewangan@nvidia.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: linux-serial@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-tegra@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Version 2 of the Server Base System Architecture (SBSAv2) describes UART
hardware registers as 32 bits wide, giving no guidance on access sizes. The
SBSA UART driver previously assumed partial-length 16 and 8 bit accesses would
work. But the SBSAv2 UART hardware on the Qualcomm Technologies QDF2432 only
supports full-length 32 bit register accesses, so use those exclusively. This
is compatible with SBSAv3, which explicitly requires UART hardware support 32
(and 16 and sometimes 8) bit accesses.

Tested on Juno, Midway, QDF2432, Seattle, and X-Gene 1.
Tested-by: NMark Langsdorf <mlangsdo@redhat.com>
Tested-by: NAndre Przywara <andre.przywara@arm.com>
Acked-by: NAndre Przywara <andre.przywara@arm.com>
Signed-off-by: NChristopher Covington <cov@codeaurora.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

PL011 UART has hardware mark/space parity ability, this trivial patch adds support for it.
Tested on Raspberry Pi v1, v2 (BCM2835 and BCM2836)
Signed-off-by: NEd Spiridonov <edo.rus@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>