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>

Signed-off-by: NAlexander Shiyan <shc_work@mail.ru>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

If IGNBRK is set without either BRKINT or PARMRK set, some uart
drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the
line discipline, when it should send either nothing or the TTYBREAK flag
set. This happens because the read_status_mask masks out the BI
condition, which uart_insert_char() then interprets as a normal 0x00 byte.

SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General
Terminal Interface - Input Modes, states:
  "If IGNBRK is set, a break condition detected on input shall be ignored;
   that is, not put on the input queue and therefore not read by any
   process."

Fix read_status_mask to include the BI bit if IGNBRK is set; the
lsr status retains the BI bit if a BREAK is recv'd, which is
subsequently ignored in uart_insert_char() when masked with the
ignore_status_mask.

Affected drivers:
8250 - all
serial_txx9
mfd
amba-pl010
amba-pl011
atmel_serial
bfin_uart
dz
ip22zilog
max310x
mxs-auart
netx-serial
pnx8xxx_uart
pxa
sb1250-duart
sccnxp
serial_ks8695
sirfsoc_uart
st-asc
vr41xx_siu
zs
sunzilog
fsl_lpuart
sunsab
ucc_uart
bcm63xx_uart
sunsu
efm32-uart
pmac_zilog
mpsc
msm_serial
m32r_sio

Unaffected drivers:
omap-serial
rp2
sa1100
imx
icom

Annotated for fixes:
altera_uart
mcf

Drivers without break detection:
21285
xilinx-uartps
altera_jtaguart
apbuart
arc-uart
clps711x
max3100
uartlite
msm_serial_hs
nwpserial
lantiq
vt8500_serial

Unknown:
samsung
mpc52xx_uart
bfin_sport_uart
cpm_uart/core

Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag'
Reported-by: NIvan <athlon_@mail.ru>
Signed-off-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Now, we start converting tty buffer functions to actually use
tty_port. This will allow us to get rid of the need of tty in many
call sites. Only tty_port will needed and hence no more
tty_port_tty_get in those paths.

Now, the one where most of tty_port_tty_get gets removed:
tty_flip_buffer_push.

IOW we also closed all the races in drivers not using tty_port_tty_get
at all yet.

Also we move tty_flip_buffer_push declaration from include/linux/tty.h
to include/linux/tty_flip.h to all others while we are changing it
anyway.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: NDavid Howells <dhowells@redhat.com>

linux/tty_flip.h is included in linux/serial_core.h. But this may (and
will) change in the future. Then we would get build errors such as:
.../tty/serial/max3107.c: In function ‘put_data_to_circ_buf’:
.../tty/serial/max3107.c:149:2: error: implicit declaration of function ‘tty_insert_flip_string’

So fix all the drviers which call tty flip buffer helpers to really
include linux/tty_flip.h. And also make sure that those include
linux/tty.h when operating with struct tty_struct.
Signed-off-by: NJiri Slaby <jslaby@suse.cz>
Cc: Alan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: NArun Sharma <asharma@fb.com>
Reviewed-by: NEric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The serial drivers are really just tty drivers, so move them to
drivers/tty/ to make things a bit neater overall.

This is part of the tty/serial driver movement proceedure as proposed by
Arnd Bergmann and approved by everyone involved a number of months ago.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Rogier Wolff <R.E.Wolff@bitwizard.nl>
Cc: Michael H. Warfield <mhw@wittsend.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

We moved this into uart_state, now move the fields out of the separate
structure and kill it off.
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Changes to the generic console support code that happened a while ago
introduced a scenario where the initial console is used in parallel with
the final console during a brief period when switching between the two is
in progress.  During that time a message about the switch-over is printed.

With some combinations of chips, firmware and drivers, such as the DEC
DZ11 clone used with the DECstation, a hang may happen because the
firmware used for the initial console may not expect the state of the chip
after it has been initialised by the driver.

This is a workaround for the DZ11 which reuses the power-management
callback to keep the transmitter of the line associated with the console
enabled.  It reflects the consensus reached in a discussion a while ago.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The below is the patch to replace blindly all possible places,
including Jack's fixes.
Signed-off-by: NTakashi Iwai <tiwai@suse.de>
(Reviewed and checked rather than blindly added)
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When loops reaches 0 the postfix decrement still subtracts, so the subsequent
test fails.
Signed-off-by: NRoel Kluin <12o3l@tiscali.nl>
Acked-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Johannes Weiner <hannes@saeurebad.de>
Cc: <stable@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is a set of changes to implement proper resource management in the
driver, including iomem space reservation and operating on physical
addresses ioremap()ped appropriately using accessory functions rather than
unportable direct assignments.

Some adjustments to code are made to reflect the architecture of the
interface, which is a centrally controlled multiport (or, as referred to
from DEC documentation, a serial line multiplexer, going up to 8 lines
originally) rather than a bundle of separate ports.

Types are changed, where applicable, to specify the width of hardware
registers explicitly.  The interrupt handler is now managed in the
->startup() and ->shutdown() calls for consistency with other drivers and
also in preparation to handle the handover from the initial firmware-based
console gracefully.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Replace all casts from "struct uart_port *" to "struct dz_port *" with a
construct based on container_of().  This makes the conversion work
irrespective of where the former struct is located within the latter.

By popular request I have implemented it as an inline function rather than
a macro this time.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

A set of changes to the way termios settings are propagated to the serial
port hardware.  The DZ11 only supports a selection of fixed baud settings,
so some requests may not be fulfilled.  Keep the old setting in such a case
and failing that resort to 9600bps.  Also add a missing update of the
transmit timeout.  And remove the explicit encoding of the line selected
from writes to the Line Parameters Register as it has been preencoded by
the ->set_termios() call already.  Finally, remove a duplicate macro for
the Receiver Enable bit.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Handle the read and ignore status masks correctly.  Handle the BREAK condition
as expected: a framing error with a null character is a BREAK, any other
framing error is a framing error indeed.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ->start_tx(), ->stop_tx() and ->stop_rx() backends are called with the
port's lock already taken.  Remove locking from within them and wrap around
calls as necessary.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rename the serial console structure so that `modpost' does not complain about
a reference to an "init" section -- "_console" is magic.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Sort the header inclusions, add a few that are needed but pulled indirectly
only and remove ones that are not really used.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Well, panic() is a little bit undue if request_irq() fails; there is probably
no need to justify it any further.  Handle the case gracefully, by
unregistering the driver.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Polled transmission is tricky enough with the DZ11 design.  While "loop" is
set to a high value, conceptually you are not allowed to transmit without
checking whether the device offers the right transmission line (yes, it is the
device that selects the line -- the driver has no control over it other than
disabling the transmitter offered if it is the wrong one), so the loop has to
be run at least once.

Well, the '1977 or PDP11 view of how serial lines should be handled...  Except
that the serial interface used to be quite an impressive board back then
rather than chip.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Cc: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Mostly in and around irq handlers.
Signed-off-by: NJeff Garzik <jgarzik@redhat.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck Tony" <tony.luck@intel.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: NDmitry Torokhov <dtor@mail.ru>
Cc: Karsten Keil <kkeil@suse.de>
Acked-by: N"John W. Linville" <linville@tuxdriver.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: David Brownell <david-b@pacbell.net>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Acked-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>
Acked-by: NHolger Schurig <hs4233@mail.mn-solutions.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove remaining references to saved registers now that
uart_handle_sysrq_char() does not want them.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This is the grungy swap all the occurrences in the right places patch that
goes with the updates.  At this point we have the same functionality as
before (except that sgttyb() returns speeds not zero) and are ready to
begin turning new stuff on providing nobody reports lots of bugs

If you are a tty driver author converting an out of tree driver the only
impact should be termios->ktermios name changes for the speed/property
setting functions from your upper layers.

If you are implementing your own TCGETS function before then your driver
was broken already and its about to get a whole lot more painful for you so
please fix it 8)

Also fill in c_ispeed/ospeed on init for most devices, although the current
code will do this for you anyway but I'd like eventually to lose that extra
paranoia

[akpm@osdl.org: bluetooth fix]
[mp3@de.ibm.com: sclp fix]
[mp3@de.ibm.com: warning fix for tty3270]
[hugh@veritas.com: fix tty_ioctl powerpc build]
[jdike@addtoit.com: uml: fix ->set_termios declaration]
Signed-off-by: NAlan Cox <alan@redhat.com>
Signed-off-by: NMartin Peschke <mp3@de.ibm.com>
Acked-by: NPeter Oberparleiter <oberpar@de.ibm.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: NHugh Dickins <hugh@veritas.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This a set of fixes mostly to make the driver actually work:

1. Actually select the line for setting parameters and receiver
   disable/enable.
2. Select the line for receive and transmit interrupt handling correctly.
3. Report the transmitter empty state correctly.
4. Set the I/O type of ports correctly.
5. Perform polled transmission correctly.
6. Don't fix the console line at ttyS3.
7. Magic SysRq support.
8. Various small bits here and there.

Tested with a DECstation 2100 (thanks Flo for making this possible).

[akpm@osdl.org: fix typo]
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Maintain a per-CPU global "struct pt_regs *" variable which can be used instead
of passing regs around manually through all ~1800 interrupt handlers in the
Linux kernel.

The regs pointer is used in few places, but it potentially costs both stack
space and code to pass it around.  On the FRV arch, removing the regs parameter
from all the genirq function results in a 20% speed up of the IRQ exit path
(ie: from leaving timer_interrupt() to leaving do_IRQ()).

Where appropriate, an arch may override the generic storage facility and do
something different with the variable.  On FRV, for instance, the address is
maintained in GR28 at all times inside the kernel as part of general exception
handling.

Having looked over the code, it appears that the parameter may be handed down
through up to twenty or so layers of functions.  Consider a USB character
device attached to a USB hub, attached to a USB controller that posts its
interrupts through a cascaded auxiliary interrupt controller.  A character
device driver may want to pass regs to the sysrq handler through the input
layer which adds another few layers of parameter passing.

I've build this code with allyesconfig for x86_64 and i386.  I've runtested the
main part of the code on FRV and i386, though I can't test most of the drivers.
I've also done partial conversion for powerpc and MIPS - these at least compile
with minimal configurations.

This will affect all archs.  Mostly the changes should be relatively easy.
Take do_IRQ(), store the regs pointer at the beginning, saving the old one:

	struct pt_regs *old_regs = set_irq_regs(regs);

And put the old one back at the end:

	set_irq_regs(old_regs);

Don't pass regs through to generic_handle_irq() or __do_IRQ().

In timer_interrupt(), this sort of change will be necessary:

	-	update_process_times(user_mode(regs));
	-	profile_tick(CPU_PROFILING, regs);
	+	update_process_times(user_mode(get_irq_regs()));
	+	profile_tick(CPU_PROFILING);

I'd like to move update_process_times()'s use of get_irq_regs() into itself,
except that i386, alone of the archs, uses something other than user_mode().

Some notes on the interrupt handling in the drivers:

 (*) input_dev() is now gone entirely.  The regs pointer is no longer stored in
     the input_dev struct.

 (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking.  It does
     something different depending on whether it's been supplied with a regs
     pointer or not.

 (*) Various IRQ handler function pointers have been moved to type
     irq_handler_t.
Signed-Off-By: NDavid Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)

Fix the following compilation error in the dz serial driver that got
introduced with the "kernel console should send CRLF not LFCR" change.

  CC      drivers/serial/dz.o
drivers/serial/dz.c: In function 'dz_console_putchar':
drivers/serial/dz.c:679: error: 'uport' undeclared (first use in this function)
drivers/serial/dz.c:679: error: (Each undeclared identifier is reported only once
drivers/serial/dz.c:679: error: for each function it appears in.)
Signed-off-by: NMartin Michlmayr <tbm@cyrius.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NThomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Signed-off-by: NJörn Engel <joern@wohnheim.fh-wedel.de>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>

Also fixes all serial drivers.
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

Glen Turner reported that writing LFCR rather than the more
traditional CRLF causes issues with some terminals.

Since this aflicts many serial drivers, extract the common code
to a library function (uart_console_write) and arrange for each
driver to supply a "putchar" function.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Convert usage of SERIAL_IO_* to UPIO_*.
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

The API and code have been through various bits of initial review by
serial driver people but they definitely need to live somewhere for a
while so the unconverted drivers can get knocked into shape, existing
drivers that have been updated can be better tuned and bugs whacked out.

This replaces the tty flip buffers with kmalloc objects in rings. In the
normal situation for an IRQ driven serial port at typical speeds the
behaviour is pretty much the same, two buffers end up allocated and the
kernel cycles between them as before.

When there are delays or at high speed we now behave far better as the
buffer pool can grow a bit rather than lose characters. This also means
that we can operate at higher speeds reliably.

For drivers that receive characters in blocks (DMA based, USB and
especially virtualisation) the layer allows a lot of driver specific
code that works around the tty layer with private secondary queues to be
removed. The IBM folks need this sort of layer, the smart serial port
people do, the virtualisers do (because a virtualised tty typically
operates at infinite speed rather than emulating 9600 baud).

Finally many drivers had invalid and unsafe attempts to avoid buffer
overflows by directly invoking tty methods extracted out of the innards
of work queue structs. These are no longer needed and all go away. That
fixes various random hangs with serial ports on overflow.

The other change in here is to optimise the receive_room path that is
used by some callers. It turns out that only one ldisc uses receive room
except asa constant and it updates it far far less than the value is
read. We thus make it a variable not a function call.

I expect the code to contain bugs due to the size alone but I'll be
watching and squashing them and feeding out new patches as it goes.

Because the buffers now dynamically expand you should only run out of
buffering when the kernel runs out of memory for real.  That means a lot of
the horrible hacks high performance drivers used to do just aren't needed any
more.

Description:

tty_insert_flip_char is an old API and continues to work as before, as does
tty_flip_buffer_push() [this is why many drivers dont need modification].  It
does now also return the number of chars inserted

There are also

tty_buffer_request_room(tty, len)

which asks for a buffer block of the length requested and returns the space
found.  This improves efficiency with hardware that knows how much to
transfer.

and tty_insert_flip_string_flags(tty, str, flags, len)

to insert a string of characters and flags

For a smart interface the usual code is

    len = tty_request_buffer_room(tty, amount_hardware_says);
    tty_insert_flip_string(tty, buffer_from_card, len);

More description!

At the moment tty buffers are attached directly to the tty.  This is causing a
lot of the problems related to tty layer locking, also problems at high speed
and also with bursty data (such as occurs in virtualised environments)

I'm working on ripping out the flip buffers and replacing them with a pool of
dynamically allocated buffers.  This allows both for old style "byte I/O"
devices and also helps virtualisation and smart devices where large blocks of
data suddenely materialise and need storing.

So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
call directly and unsafely into function pointers it provides.  This will all
break.  Most drivers can use tty_insert_flip_char which can be kept as an API
but others need more.

At the moment I've added the following interfaces, if people think more will
be needed now is a good time to say

 int tty_buffer_request_room(tty, size)

Try and ensure at least size bytes are available, returns actual room (may be
zero).  At the moment it just uses the flipbuf space but that will change.
Repeated calls without characters being added are not cumulative.  (ie if you
call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
other functions will also try and grow buffers in future but this will be a
more efficient way when you know block sizes.

 int tty_insert_flip_char(tty, ch, flag)

As before insert a character if there is room.  Now returns 1 for success, 0
for failure.

 int tty_insert_flip_string(tty, str, len)

Insert a block of non error characters.  Returns the number inserted.

 int tty_prepare_flip_string(tty, strptr, len)

Adjust the buffer to allow len characters to be added.  Returns a buffer
pointer in strptr and the length available.  This allows for hardware that
needs to use functions like insl or mencpy_fromio.
Signed-off-by: NAlan Cox <alan@redhat.com>
Cc: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: NHirokazu Takata <takata@linux-m32r.org>
Signed-off-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NJeff Dike <jdike@addtoit.com>
Signed-off-by: NJohn Hawkes <hawkes@sgi.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NAdrian Bunk <bunk@stusta.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

Use physical addresses at the interface level, letting drivers remap
them as appropriate.
Signed-off-by: NMaciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!