ARC cores on reset have all interrupt lines of built-in INTC enabled.
Which means once we globally enable interrupts (very early on boot)
faulty hardware blocks may trigger an interrupt that Linux kernel
cannot handle yet as corresponding handler is not yet installed.
In that case system falls in "interrupt storm" and basically never
does anything useful except entering and exiting generic IRQ handling
code.
One real example of that kind of problematic hardware is DW GMAC which
also has interrupts enabled on reset and if Ethernet PHY informs GMAC
about link state, GMAC immediately reports that upstream to ARC core
and here we are.
Now with that change we mask all individual IRQ lines making entire
system more fool-proof.
[This patch was motivated by Adaptrum platform support]
Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Eugeniy Paltsev <paltsev@synopsys.com>
Tested-by: Alexandru Gagniuc <alex.g@adaptrum.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
After reset all interrupts in the core interrupt controller has
the highest priority P0. If the platform supports Fast IRQs and
has more than 1 banks of registers then CPU automatically switch
banks of registers when P0 interrupt comes.
The problem is that the kernel expects that by default switching
of banks is not used by all interrupts. It is necessary to set a
default nonzero priority for all available interrupts to avoid
undefined behaviour.
Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
It is better to use it instead of magic numbers.
Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
It is necessary to use hwirq instead of virq when you communicate
with an interrupt controller since there is no guaranty that virq
numbers match hwirq numbers.
Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC HS Cores support configurable multiple interrupt priorities of upto
16 levels. In commit dec2b2849c ("ARCv2: intc: Allow interruption by
lowest priority interrupt") we switched to 15 which seems a bit
excessive given that there would be rare hardware implementing so many
preemption levels AND running Linux. It would seem that 2 levels will be
more common so switch to 1 as the default priority level. This will be
the "lower" priority level saving 0 for implementing NMI style support.
This scheme also works in systems with more than 2 prioity levels as
well.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
In the end of "arc_init_IRQ" STATUS32.IE flag is going to be affected by
"flag" instruction but "flag" never touches IE flag on ARCv2. So "kflag"
instruction must be used instead of "flag".
Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Cc: stable@vger.kernel.org #4.2+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Now that we have Timers probed from DT, don't need legacy domain
This however requires mapping to be called explicitly for the IRQ which
still can't (and probably never) be probed from DT such as IPI and
SOFTIRQ
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The primary interrupt handler arch_do_IRQ() was passing hwirq as linux
virq to core code. This was fragile and worked so far as we only had legacy/linear
domains.
This came out of a rant by Marc Zyngier.
http://lists.infradead.org/pipermail/linux-snps-arc/2015-December/000298.html
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC HS Cores support configurable multiple interrupt priorities of upto
16 levels.
There is processor "interrupt preemption threshhold" in STATUS32.E[4:1]
And several places need to set this up:
1. seed value as kernel is booting
2. seed value for user space programs
3. Arg to SLEEP instruction in idle task (what interrupt prio can wake)
4. Per-IRQ line prioirty (i.e. what is the priority of interrupt
raised by a peripheral or timer or perf counter...
Currently above sites use the highest priority 0. This can be potential
problem when multiple priorities are supported. e.g. user space could
only be interrupted by P0 interrupt, not others...
So turn this over and instead make default interruption level to be
the lowest priority possible 15. This should be fine even if there are
fewer priority levels configured (say two: P0 HIGH, P1 LOW)
This feature also effectively disables FIRQ feature if present in
hardware config. With old code, a P0 interrupt would be FIRQ, needing
special handling (ISR or Register Banks) which is NOT supported yet.
Now it not be P0 (P15 or whatever is lowest prio) so FIRQ is not
triggered.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The IRQCHIP_DECLARE macro migrated to 'include/linux/irqchip.h'.
See commit 91e20b5040
("irqchip: Move IRQCHIP_DECLARE macro to include/linux/irqchip.h").
This patch removes the inclusions of private header 'drivers/irqchip/irqchip.h'
and if necessary replaces them with inclusions of 'include/linux/irqchip.h'.
Signed-off-by: Joel Porquet <joel@porquet.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Alexey Brodkin