The current implementation uses a sequence of a cacheflush and a copy.
This is racy in case of a multithreaded debuggee and renders GDB
virtually unusable.
Aside this fixes a performance hog rendering access to /proc/cmdline very
slow and resulting in a enough cache stalls for the 34K AP/SP programming
model to make the bare metal code on the non-Linux VPE miss RT deadlines.
The main part of this patch was originally written by Ralf Baechle;
Atushi Nemoto did the the debugging.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
With the existing prototype the following code:
const void __iomem *io = ioremap();
x = readb(io);
iounmap(io);
did result in a warning.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
[MIPS] Pass NULL not 0 for pointer value.
[MIPS] IP27: Make declaration of setup_replication_mask a proper prototype.
[MIPS] BigSur: More useful defconfig.
[MIPS] Cleanup definitions of speed_t and tcflag_t.
[MIPS] Fix compilation warnings in arch/mips/sibyte/bcm1480/smp.c
[MIPS] Optimize and cleanup get_saved_sp, set_saved_sp
[MIPS] <asm/irq.h> does not need pt_regs anymore.
[MIPS] Workaround for bug in gcc -EB / -EL options.
[MIPS] Fix timer setup for Jazz
If CONFIG_BUILD_ELF64 was not selected and gcc had -msym32 option
(i.e. 4.0 or newer), there is no point to use %highest, %higher for
kernel symbols.
This patch also fixes 64-bit SMTC version of get_saved_sp() which is
broken but harmless since there is no such CPUs for now.
A bonus is set_saved_sp() and SMP version of get_saved_sp() are more
readable now.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
There's nothing arch-specific about check_signature(), so move it to
<linux/io.h>. Use a cross between the Alpha and i386 implementations as
the generic one.
Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make sure cpu_has_fpu (which uses smp_processor_id()) is used only in
atomic context.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Use the new typedef for interrupt handler function pointers rather than
actually spelling out the full thing each time. This was scripted with the
following small shell script:
#!/bin/sh
egrep -nHrl -e 'irqreturn_t[ ]*[(][*]' $* |
while read i
do
echo $i
perl -pi -e 's/irqreturn_t\s*[(]\s*[*]\s*([_a-zA-Z0-9]*)\s*[)]\s*[(]\s*int\s*,\s*void\s*[*]\s*[)]/irq_handler_t \1/g' $i || exit $?
done
Signed-Off-By: David Howells <dhowells@redhat.com>
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: David Howells <dhowells@redhat.com>
(cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
This patch fixes the compilation errors on PNX8550 and hard-to-track
bug in interrupt handling.
It also corresponds to the latest changes in PNX8550 serial driver.
Signed-off-by: Vitaly Wool <vitalywool@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial: (39 commits)
Add missing maintainer countries in CREDITS
Fix bytes <-> kilobytes typo in Kconfig for ramdisk
fix a typo in Documentation/pi-futex.txt
BUG_ON conversion for fs/xfs/
BUG_ON() conversion in fs/nfsd/
BUG_ON conversion for fs/reiserfs
BUG_ON cleanups in arch/i386
BUG_ON cleanup in drivers/net/tokenring/
BUG_ON cleanup for drivers/md/
kerneldoc-typo in led-class.c
debugfs: spelling fix
rcutorture: Fix incorrect description of default for nreaders parameter
parport: Remove space in function calls
Michal Wronski: update contact info
Spelling fix: "control" instead of "cotrol"
reboot parameter in Documentation/kernel-parameters.txt
Fix copy&waste bug in comment in scripts/kernel-doc
remove duplicate "until" from kernel/workqueue.c
ite_gpio fix tabbage
fix file specification in comments
...
Fixed trivial path conflicts due to removed files:
arch/mips/dec/boot/decstation.c, drivers/char/ite_gpio.c
Many files include the filename at the beginning, serveral used a wrong one.
Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
As per feature-removal-schedule.txt.
Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Acked-by: Alan Cox <alan@redhat.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The stack pointer in MIPS/gcc should always 8 bytes aligned on
entry to any routines. Therefore pt_regs structure must be
aligned to 8-byte boundary too.
Instead of creating dummy fields to achieve this alignment, this
patch let gcc doing it. Therefore 'smtc_pad' field can be safely
removed.
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Introduce the child field in sched_domain struct and use it in
sched_balance_self().
We will also use this field in cleaning up the sched group cpu_power
setup(done in a different patch) code.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The last in-kernel user of errno is gone, so we should remove the definition
and everything referring to it. This also removes the now-unused lib/execve.c
file that was introduced earlier.
Also remove every trace of __KERNEL_SYSCALLS__ that still remained in the
kernel.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andi Kleen <ak@muc.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Hirokazu Takata <takata.hirokazu@renesas.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If the PC was ret_from_irq or ret_from_exception, there will be no
more normal stackframe. Instead of stopping the unwinding, use PC and
RA saved by an exception handler to continue unwinding into the
interrupted context. This also simplifies the CONFIG_STACKTRACE code.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Implement stacktrace interface by using unwind_stack() and enable lockdep
support in Kconfig.
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
In handle_sys and its variants, we must reload some registers which
might be clobbered by trace_hardirqs_on().
Also we must make sure trace_hardirqs_on() called in kernel level (not
exception level).
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
On systems running with virtual cpus there is optimization potential in
regard to spinlocks and rw-locks. If the virtual cpu that has taken a lock
is known to a cpu that wants to acquire the same lock it is beneficial to
yield the timeslice of the virtual cpu in favour of the cpu that has the
lock (directed yield).
With CONFIG_PREEMPT="n" this can be implemented by the architecture without
common code changes. Powerpc already does this.
With CONFIG_PREEMPT="y" the lock loops are coded with _raw_spin_trylock,
_raw_read_trylock and _raw_write_trylock in kernel/spinlock.c. If the lock
could not be taken cpu_relax is called. A directed yield is not possible
because cpu_relax doesn't know anything about the lock. To be able to
yield the lock in favour of the current lock holder variants of cpu_relax
for spinlocks and rw-locks are needed. The new _raw_spin_relax,
_raw_read_relax and _raw_write_relax primitives differ from cpu_relax
insofar that they have an argument: a pointer to the lock structure.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
MIPS is the only port to call its fstatat()-related syscalls
"__NR_fstatat". Now I can see why that might be seen as every
other port being wrong, but I think for o32, it is at best confusing.
__NR_fstat provides a plain (32-bit) stat while __NR_fstatat provides a
64-bit stat. Changing the name to __NR_fstatat64 would make things more
explicit, match x86, and make the glibc port slightly easier.
The current name is more appropriate for n32 and n64, but it would be
appropriate for other 64-bit targets too, and those targets have chosen
to call it __NR_newfstatat instead. Using the same name for MIPS would
again be more consistent and make the glibc port slightly easier.
I'm not wedded to this idea if the current names are preferred,
but FWIW...
Signed-off-by: Richard Sandiford <richard@codesourcery.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The code in pgtable-64.h assumes TASK_SIZE is always bigger than a first
level PGDIR_SIZE. This is not the case for 64K pages, where task size is
40 bits (1TB) and a pgd entry can map 42 bits. This leads to
USER_PTRS_PER_PGD being zero for 64K pages.
Signed-off-by: Peter Watkins <treestem@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
excite_fpga.h, like all platform headers, really belongs in the
platform header directory.
Signed-off-by: Thomas Koeller <thomas.koeller@baslerweb.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The following change updates the Atlas interrupt handling to match that
of Malta. Tested with a 5Kc and a 34Kf successfully.
Signed-off-by: Maciej W. Rozycki <macro@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Atlas maps its RTC chip in the host mmio space rather than using the
"traditional" location in the PCI/ISA port space. A change that has
happened to the generic RTC header requires to define ARCH_RTC_LOCATION
now.
Signed-off-by: Maciej W. Rozycki <macro@mips.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
* export asm/sgidefs.h
* include asm/isadep.h only if in kernel
* do not export contents of asm/timex.h and asm/user.h
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
