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8 Commits (f40031c2314a592ff348193704e5f71e9a7e0449)

Author SHA1 Message Date
Thomas Gleixner 853f90d49b timers, drivers/tty/mips_ejtag: Initialize the poll timer as pinned
Pinned timers must carry the pinned attribute in the timer structure
itself, so convert the code to the new API.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Chris Mason <clm@fb.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: George Spelvin <linux@sciencehorizons.net>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160704094341.537448301@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-07 10:34:59 +02:00
James Hogan 3e8137a185 ttyFDC: Fix build problems due to use of module_{init,exit}
Commit 0fd972a7d9 (module: relocate module_init from init.h to
module.h) broke the build of ttyFDC driver due to that driver's (mis)use
of module_mips_cdmm_driver() without first including module.h, for
example:

In file included from ./arch/mips/include/asm/cdmm.h +11 :0,
                 from drivers/tty/mips_ejtag_fdc.c +34 :
include/linux/device.h +1295 :1: warning: data definition has no type or storage class
./arch/mips/include/asm/cdmm.h +84 :2: note: in expansion of macro ‘module_driver’
drivers/tty/mips_ejtag_fdc.c +1157 :1: note: in expansion of macro ‘module_mips_cdmm_driver’
include/linux/device.h +1295 :1: error: type defaults to ‘int’ in declaration of ‘module_init’ [-Werror=implicit-int]
./arch/mips/include/asm/cdmm.h +84 :2: note: in expansion of macro ‘module_driver’
drivers/tty/mips_ejtag_fdc.c +1157 :1: note: in expansion of macro ‘module_mips_cdmm_driver’
drivers/tty/mips_ejtag_fdc.c +1157 :1: warning: parameter names (without types) in function declaration

Instead of just adding the module.h include, switch to using the new
builtin_mips_cdmm_driver() helper macro and drop the remove callback,
since it isn't needed. If module support is added later, the code can
always be resurrected.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 4.2.x-
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-17 21:29:21 -07:00
Sudeep Holla b801e7f898 MIPS: ttyFDC: replace IRQF_NO_SUSPEND with IRQF_COND_SUSPEND
Since the FD interrupt handler can discern spurious IRQs and it is
shared with timer interrupt, use IRQF_COND_SUSPEND instead of
IRQF_NO_SUSPEND.

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-04 19:11:05 +01:00
Bjorn Helgaas 770847bad0 MIPS: Remove "weak" from get_c0_fdc_int() declaration
Weak header file declarations are error-prone because they make every
definition weak, and the linker chooses one based on link order (see
10629d711e ("PCI: Remove __weak annotation from pcibios_get_phb_of_node
decl")).

The most elegant solution is to have a weak default implementation and
allow a strong function to override it.  Then we don't have to test
whether a definition is present, and if there are ever multiple strong
definitions, we get a link error instead of calling a random definition.

Add a weak get_c0_fdc_int() definition with the default code and remove the
weak annotation from the declaration.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10687/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-09-03 12:07:38 +02:00
James Hogan 70f041b6e1 ttyFDC: Fix to use native endian MMIO reads
The MIPS Common Device Memory Map (CDMM) is internal to the core and has
native endianness. There is therefore no need to byte swap the accesses
on big endian targets, so convert the Fast Debug Channel (FDC) TTY
driver to use __raw_readl()/__raw_writel() rather than
ioread32()/iowrite32().

Fixes: 4cebec609a ("TTY: Add MIPS EJTAG Fast Debug Channel TTY driver")
Fixes: c2d7ef51d7 ("ttyFDC: Implement KGDB IO operations.")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9905/
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-05-26 16:46:52 +02:00
James Hogan c2d7ef51d7 ttyFDC: Implement KGDB IO operations.
Implement KGDB IO operations for MIPS Fast Debug Channel (FDC). This can
be enabled via Kconfig, which also allows the channel number to be
chosen.

The magic sysrq hack is implemented in the TTY driver, detecting just ^C
for the KGDB channel, and ^O followed by a letter for the FDC console
channel.

The KGDB operations are reasonably efficient thanks to the flush
callback, with a 4 byte buffer being used in both directions to allow up
to 4 bytes to be encoded per FDC word. Reading of data for KGDB will
discard any data received on other channels, which clearly isn't ideal,
but given that there is a single FIFO shared between channels we can't
do much better.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: linux-mips@linux-mips.org
Cc: kgdb-bugreport@lists.sourceforge.net
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9147/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-31 12:04:13 +02:00
James Hogan e934945db7 MIPS, ttyFDC: Add early FDC console support
Add support for early console of MIPS Fast Debug Channel (FDC) on
channel 1 with a call very early from the MIPS setup_arch().

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9145/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-31 12:04:12 +02:00
James Hogan 4cebec609a TTY: Add MIPS EJTAG Fast Debug Channel TTY driver
Add TTY driver and consoles for the MIPS EJTAG Fast Debug Channel (FDC),
which is found on the per-CPU MIPS Common Device Mapped Memory (CDMM)
bus.

The FDC is a per-CPU device which is used to communicate with an EJTAG
probe. RX and TX FIFOs exist, containing 32-bits of data and 4-bit
channel numbers. 16 general data streams are implemented on this for TTY
and console use by encoding up to 4 bytes on each 32-bit FDC word.

The TTY devices are named e.g. /dev/ttyFDC3c2 for channel 2 of the FDC
attached to logical CPU 3.

These can be used for getting the kernel log, a login prompt, or as a
GDB remote transport, all over EJTAG and without needing a serial port.

It can have an interrupt to notify of when incoming data is available in
the RX FIFO or when the TX FIFO is no longer full. The detection of this
interrupt occurs in architecture / platform code, but it may be shared
with the timer and/or performance counter interrupt.

Due to the per-CPU nature of the hardware, all outgoing TTY data is
written out from a kthread which is pinned to the appropriate CPU.

The console is not bound to a specific CPU, so output will appear on the
chosen channel on whichever CPU the code is executing on. Enable with
e.g. console=fdc1 in kernel arguments. /dev/console is bound to the same
channel on the boot CPU's FDC if it exists.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/9146/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2015-03-31 12:04:12 +02:00