Currently Kconfig knob ARC_NUMBER_OF_INTERRUPTS is used as indicator of
hard irq count. But it is flawed that it doesn't affect
- NR_IRQS : for number of virtual interrupts
- NR_CPU_IRQS : for number of hardware interrupts
Moreover the actual hardware irq count might still not be same as
ARC_NUMBER_OF_INTERRUPTS. So use the information availble in the
Build Configuration Registers and get rid of the Kconfig option.
We still need "some" build time info about irq count to set up
sufficient number of vector table entries. This is done with a
sufficiently large NR_CPU_IRQS which will eventually be used soley for
that purpose (subsequent patches will remove its usage elsewhere)
So to summarize what this patch does:
* NR_CPU_IRQS defines a maximum number of hardware interrupts.
* Remove ARC_NUMBER_OF_INTERRUPTS option and create interrupts
table for all possible hardware interrupts.
* Increase a maximum number of virtual IRQs to 512. ARCv2 can
support 240 interrupts in the core interrupts controllers
and 128 interrupts in IDU. Thus 512 virtual IRQs must be
enough for most configurations of boards.
This patch leads to NR_CPU_IRQS in 2 places, to reduce the overall
churn. The next patch will remove the 2nd definition anyways.
Signed-off-by: Yuriy Kolerov <yuriy.kolerov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
[vgupta: reworked the changelog a bit]
This will be needed for switching to linear irq domain as
irq_create_mapping() called by intr code needs the IRQ numbers
in addition to existing usage in mcip.c for requesting the irq
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
- timer frequency is derived from DT (no longer rely on top level
DT "clock-frequency" probed early and exported by asm/clk.h)
- TIMER0_IRQ need not be exported across arch code, confined to intc as
it is property of same
- Any failures in clockevent setup are considered pedantic and system
panic()'s as there is no generic fallback (unlike clocksource where
a jiffies based soft clocksource always exists)
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
ARC Timers so far have been handled as "legacy" w/o explicit description
in DT. This poses challenge for newer platforms wanting to use them.
This series will eventually help move timers over to DT.
This patch does a small change of using a CPU notifier to set clockevent
on non-boot CPUs. So explicit setup is done only on boot CPU (which will
later be done by DT)
Signed-off-by: Noam Camus <noamc@ezchip.com>
[vgupta: broken off from a bigger patch]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
- The idea is to remove the API usage since it has a subltle
design flaw - relies on being called on cpu0 first. This is true for
some early per cpu irqs such as TIMER/IPI, but not for late probed
per cpu peripherals such a perf. And it's usage in perf has already
bitten us once: see c6317bc7c5
("ARCv2: perf: Ensure perf intr gets enabled on all cores") where we
ended up open coding it anyways
- The seeming duplication will go away once we start using cpu notifier
for timer setup
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
There is no real ARC700 based SMP SoC so remove IPI definition.
EZChip's SMP ARC700 is going to use a different intc and IPI provider
anyways.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The reason this was not done so far was lack of genuine IPI_IRQ for
ARC700, as we don't have a SMP version of core yet (which might change
soon thx to EZChip). Nevertheles to increase the build coverage, we
need to allow CONFIG_SMP for ARC700 and still be able to run it on a
UP platform (nsim or AXS101) with a UP Device Tree (SMP-on-UP)
The build itself requires some define for IPI_IRQ and even a dummy
value is fine since that code won't run anyways.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
The current cpu-private IRQ registration is ugly as it requires need to
expose arch_unmask_irq() outside of intc code.
So switch to percpu IRQ APIs:
-request_percpu_irq [boot core]
-enable_percpu_irq [all cores]
Encapsulated in helper arc_request_percpu_irq()
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
get_hw_config_num_irq() may be called by normal iss_model_init_smp()
which is a function pointer for 'init_smp' which may be called by
first_lines_of_secondary() which also need be normal too.
The related warning (with allmodconfig):
MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x5814): Section mismatch in reference from the function iss_model_init_smp() to the function .init.text:get_hw_config_num_irq()
The function iss_model_init_smp() references
the function __init get_hw_config_num_irq().
This is often because iss_model_init_smp lacks a __init
annotation or the annotation of get_hw_config_num_irq is wrong.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
They haven't '__init' in definition, but has '__init' in declaration.
And normal function start_kernel_secondary() may call setup_processor()
which will call arc_init_IRQ().
So need remove '__init' for both of them. The related warning (with
allmodconfig):
MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x3084): Section mismatch in reference from the function start_kernel_secondary() to the function .init.text:setup_processor()
The function start_kernel_secondary() references
the function __init setup_processor().
This is often because start_kernel_secondary lacks a __init
annotation or the annotation of setup_processor is wrong.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
The __cpuinit type of throwaway sections might have made sense
some time ago when RAM was more constrained, but now the savings
do not offset the cost and complications. For example, the fix in
commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time")
is a good example of the nasty type of bugs that can be created
with improper use of the various __init prefixes.
After a discussion on LKML[1] it was decided that cpuinit should go
the way of devinit and be phased out. Once all the users are gone,
we can then finally remove the macros themselves from linux/init.h.
Note that some harmless section mismatch warnings may result, since
notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c)
are flagged as __cpuinit -- so if we remove the __cpuinit from
arch specific callers, we will also get section mismatch warnings.
As an intermediate step, we intend to turn the linux/init.h cpuinit
content into no-ops as early as possible, since that will get rid
of these warnings. In any case, they are temporary and harmless.
This removes all the arch/arc uses of the __cpuinit macros from
all C files. Currently arc does not have any __CPUINIT used in
assembly files.
[1] https://lkml.org/lkml/2013/5/20/589
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This patch adds some room for CPU-external interrupt controllers in the
Linux interrupt space. Until now, only the 32 CPU internal interrupt lines
were supported which does not allow for external interrupt controllers such
as GPIO modules etc.
Signed-off-by: Christian Ruppert <christian.ruppert@abilis.com>
Signed-off-by: Pierrick Hascoet <pierrick.hascoet@abilis.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
For now this will suffice for all platforms, later exotic ones needs to
get this from DeviceTree
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
-platform API is retired and instead callbacks are used
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Acked-by: Arnd Bergmann <arnd@arndb.de>
N.B. This is old style of hardcoding platform device specific info
in code and it's instantiation thererof using platform_add_devices().
Subsequent patches replace this with DeviceTree based runtime probe.
This patch has been retained just as an example of "don't-do-this" for
newer kernel ports.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
ARC700 includes 2 in-core 32bit timers TIMER0 and TIMER1.
Both have exactly same capabilies.
* programmable to count from TIMER<n>_CNT to TIMER<n>_LIMIT
* for count 0 and LIMIT ~1, provides a free-running counter by
auto-wrapping when limit is reached.
* optionally interrupt when LIMIT is reached (oneshot event semantics)
* rearming the interrupt provides periodic semantics
* run at CPU clk
ARC Linux uses TIMER0 for clockevent (periodic/oneshot) and TIMER1 for
clocksource (free-running clock).
Newer cores provide RTSC insn which gives a 64bit cpu clk snapshot hence
is more apt for clocksource when available.
SMP poses a bit of challenge for global timekeeping clocksource /
sched_clock() backend:
-TIMER1 based local clocks are out-of-sync hence can't be used
(thus we default to jiffies based cs as well as sched_clock() one/both
of which platform can override with it's specific hardware assist)
-RTSC is only allowed in SMP if it's cross-core-sync (Kconfig glue
ensures that) and thus usable for both requirements.
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Vineet Gupta