The MIPS GIC supports 7 local interrupts, 2 of which are the GIC
local watchdog and count/compare timer. The remainder are CPU
interrupts which may optionally be re-routed through the GIC.
GIC hardware IRQs 0-6 are now used for local interrupts while
hardware IRQs 7+ are used for external (shared) interrupts.
Note that the 5 CPU interrupts may not be re-routable through
the GIC. In that case mapping will fail and the vectors reported
in C0_IntCtl should be used instead. gic_get_c0_compare_int() and
gic_get_c0_perfcount_int() will return the correct IRQ number to
use for the C0 timer and perfcounter interrupts based on the
routability of those interrupts through the GIC.
A separate irq_chip, with callbacks that mask/unmask the local
interrupt on all CPUs, is used for the C0 timer and performance
counter interrupts since all other platforms do not use the percpu
IRQ API for those interrupts.
Malta, SEAD-3, and the GIC clockevent driver have been updated
to use local interrupts and the R4K clockevent driver has been
updated to poll for C0 timer interrupts through the GIC when
the GIC is present.
Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Reviewed-by: Qais Yousef <qais.yousef@imgtec.com>
Tested-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeffrey Deans <jeffrey.deans@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: John Crispin <blogic@openwrt.org>
Cc: David Daney <ddaney.cavm@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7819/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Add new 'noftlb' kernel command line option to disable the FTLB.
Since the kernel command line is not available when probing and
enabling the CPU features in cpu_probe(), we let the kernel configure
the FTLB during the config4 decode operation and we disable the FTLB later
on, once the command line has become available to us. This should have
no negative effects since FTLB isn't used so early in the boot process.
FTLB increases the effective TLB size leading to less TLB misses. However,
sometimes it's useful to be able to disable it when debugging memory related
core features or other hardware components.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/7586/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Caller (generic PCI code) already do proper locking so no need to add
another one here. Local PCI read/write functions are never called
simultaneously, also they do not require synchronization with the PCI
controller ops, since they are used before the controller registration.
Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Cc: Linux MIPS <linux-mips@linux-mips.org>
Cc: Gabor Juhos <juhosg@openwrt.org>
Patchwork: https://patchwork.linux-mips.org/patch/7603/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Currently, arch_trigger_all_cpu_backtrace() is defined in only x86 and
sparc which have an NMI. But in case of softlockup, it could be possible
to dump backtrace of all cpus. and this could be helpful for debugging.
for example, if system has 2 cpus.
CPU 0 CPU 1
acquire read_lock()
try to do write_lock()
,,,
missing read_unlock()
In this case, softlockup will occur becasuse CPU 0 does not call
read_unlock(). And dump_stack() print only backtrace for "CPU 0". If
CPU1's backtrace is printed it's very helpful.
[ralf@linux-mips.org: Fixed whitespace and formatting issues.]
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8200/
Based on the spatch
@@
expression e;
@@
- return (e);
+ return e;
with heavy hand editing because some of the changes are either whitespace
or identation only or result in excessivly long lines.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
x86 call do_notify_resume on paranoid returns if TIF_UPROBE is set but
not on non-paranoid returns. I suspect that this is a mistake and that
the code only works because int3 is paranoid.
Setting _TIF_NOTIFY_RESUME in the uprobe code was probably a workaround
for the x86 bug. With that bug fixed, we can remove _TIF_NOTIFY_RESUME
from the uprobes code.
Reported-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Chris bisected a NULL pointer deference in task_sched_runtime() to
commit 6e998916df 'sched/cputime: Fix clock_nanosleep()/clock_gettime()
inconsistency'.
Chris observed crashes in atop or other /proc walking programs when he
started fork bombs on his machine. He assumed that this is a new exit
race, but that does not make any sense when looking at that commit.
What's interesting is that, the commit provides update_curr callbacks
for all scheduling classes except stop_task and idle_task.
While nothing can ever hit that via the clock_nanosleep() and
clock_gettime() interfaces, which have been the target of the commit in
question, the author obviously forgot that there are other code paths
which invoke task_sched_runtime()
do_task_stat(()
thread_group_cputime_adjusted()
thread_group_cputime()
task_cputime()
task_sched_runtime()
if (task_current(rq, p) && task_on_rq_queued(p)) {
update_rq_clock(rq);
up->sched_class->update_curr(rq);
}
If the stats are read for a stomp machine task, aka 'migration/N' and
that task is current on its cpu, this will happily call the NULL pointer
of stop_task->update_curr. Ooops.
Chris observation that this happens faster when he runs the fork bomb
makes sense as the fork bomb will kick migration threads more often so
the probability to hit the issue will increase.
Add the missing update_curr callbacks to the scheduler classes stop_task
and idle_task. While idle tasks cannot be monitored via /proc we have
other means to hit the idle case.
Fixes: 6e998916df 'sched/cputime: Fix clock_nanosleep()/clock_gettime() inconsistency'
Reported-by: Chris Mason <clm@fb.com>
Reported-and-tested-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Stanislaw Gruszka <sgruszka@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge x86-64 iret fixes from Andy Lutomirski:
"This addresses the following issues:
- an unrecoverable double-fault triggerable with modify_ldt.
- invalid stack usage in espfix64 failed IRET recovery from IST
context.
- invalid stack usage in non-espfix64 failed IRET recovery from IST
context.
It also makes a good but IMO scary change: non-espfix64 failed IRET
will now report the correct error. Hopefully nothing depended on the
old incorrect behavior, but maybe Wine will get confused in some
obscure corner case"
* emailed patches from Andy Lutomirski <luto@amacapital.net>:
x86_64, traps: Rework bad_iret
x86_64, traps: Stop using IST for #SS
x86_64, traps: Fix the espfix64 #DF fixup and rewrite it in C
It's possible for iretq to userspace to fail. This can happen because
of a bad CS, SS, or RIP.
Historically, we've handled it by fixing up an exception from iretq to
land at bad_iret, which pretends that the failed iret frame was really
the hardware part of #GP(0) from userspace. To make this work, there's
an extra fixup to fudge the gs base into a usable state.
This is suboptimal because it loses the original exception. It's also
buggy because there's no guarantee that we were on the kernel stack to
begin with. For example, if the failing iret happened on return from an
NMI, then we'll end up executing general_protection on the NMI stack.
This is bad for several reasons, the most immediate of which is that
general_protection, as a non-paranoid idtentry, will try to deliver
signals and/or schedule from the wrong stack.
This patch throws out bad_iret entirely. As a replacement, it augments
the existing swapgs fudge into a full-blown iret fixup, mostly written
in C. It's should be clearer and more correct.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On a 32-bit kernel, this has no effect, since there are no IST stacks.
On a 64-bit kernel, #SS can only happen in user code, on a failed iret
to user space, a canonical violation on access via RSP or RBP, or a
genuine stack segment violation in 32-bit kernel code. The first two
cases don't need IST, and the latter two cases are unlikely fatal bugs,
and promoting them to double faults would be fine.
This fixes a bug in which the espfix64 code mishandles a stack segment
violation.
This saves 4k of memory per CPU and a tiny bit of code.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There's nothing special enough about the espfix64 double fault fixup to
justify writing it in assembly. Move it to C.
This also fixes a bug: if the double fault came from an IST stack, the
old asm code would return to a partially uninitialized stack frame.
Fixes: 3891a04aaf
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull ARM SoC fixes from Olof Johansson:
"A collection of fixes this week:
- A set of clock fixes for shmobile platforms
- A fix for tegra that moves serial port labels to be per board.
We're choosing to merge this for 3.18 because the labels will start
being parsed in 3.19, and without this change serial port numbers
that used to be stable since the dawn of time will change numbers.
- A few other DT tweaks for Tegra.
- A fix for multi_v7_defconfig that makes it stop spewing cpufreq
errors on Arndale (Exynos)"
* tag 'armsoc-for-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
ARM: multi_v7_defconfig: fix failure setting CPU voltage by enabling dependent I2C controller
ARM: tegra: roth: Fix SD card VDD_IO regulator
ARM: tegra: Remove eMMC vmmc property for roth/tn7
ARM: dts: tegra: move serial aliases to per-board
ARM: tegra: Add serial port labels to Tegra124 DT
ARM: shmobile: kzm9g legacy: Set i2c clks_per_count to 2
ARM: shmobile: r8a7740 dtsi: Correct IIC0 parent clock
ARM: shmobile: r8a7790: Fix SD3CKCR address to device tree
ARM: shmobile: r8a7740 legacy: Correct IIC0 parent clock
ARM: shmobile: r8a7740 legacy: Add missing INTCA clock for irqpin module
ARM: shmobile: r8a7790: Fix SD3CKCR address
ARM: dts: sun6i: Re-parent ahb1_mux to pll6 as required by dma controller
Pull percpu fix from Tejun Heo:
"This contains one patch to fix a race condition which can lead to
percpu_ref using a percpu pointer which is corrupted with a set DEAD
bit. The bug was introduced while separating out the ATOMIC mode flag
from the DEAD flag. The fix is pretty straight forward.
I just committed the patch to the percpu tree but am sending out the
pull request early as I'll be on vacation for a week. The patch
should be fairly safe and while the latency will be higher I'll be
checking emails"
* 'for-3.18-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
percpu-ref: fix DEAD flag contamination of percpu pointer
Pull btrfs deadlock fix from Chris Mason:
"This has a fix for a long standing deadlock that we've been trying to
nail down for a while. It ended up being a bad interaction with the
fair reader/writer locks and the order btrfs reacquires locks in the
btree"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
btrfs: fix lockups from btrfs_clear_path_blocking
While decoupling ATOMIC and DEAD flags, f47ad45784 ("percpu_ref:
decouple switching to percpu mode and reinit") updated
__ref_is_percpu() so that it only tests ATOMIC flag to determine
whether the ref is in percpu mode or not; however, while DEAD implies
ATOMIC, the two flags are set separately during percpu_ref_kill() and
if __ref_is_percpu() races percpu_ref_kill(), it may see DEAD w/o
ATOMIC. Because __ref_is_percpu() returns @ref->percpu_count_ptr
value verbatim as the percpu pointer after testing ATOMIC, the pointer
may now be contaminated with the DEAD flag.
This can be fixed by clearing the flag bits before returning the
pointer which was the fix proposed by Shaohua; however, as DEAD
implies ATOMIC, we can just test for both flags at once and avoid the
explicit masking.
Update __ref_is_percpu() so that it tests that both ATOMIC and DEAD
are clear before returning @ref->percpu_count_ptr as the percpu
pointer.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-Reviewed-by: Shaohua Li <shli@kernel.org>
Link: http://lkml.kernel.org/r/995deb699f5b873c45d667df4add3b06f73c2c25.1416638887.git.shli@kernel.org
Fixes: f47ad45784 ("percpu_ref: decouple switching to percpu mode and reinit")
Pull timer fix from Thomas Gleixner:
"A single bugfix for an init order problem in the sun4i subarch
clockevents code"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clockevent: sun4i: Fix race condition in the probe code
