Migrate alpha driver to the new 'set-state' interface provided by clockevents core, the earlier 'set-mode' interface is marked obsolete now. This also enables us to implement callbacks for new states of clockevent devices, for example: ONESHOT_STOPPED. rtc clockevent device wasn't doing anything in set-mode and so its set-state callbacks aren't implemented. Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: linux-alpha@vger.kernel.org Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
__get_cpu_var() is used for multiple purposes in the kernel source. One of
them is address calculation via the form &__get_cpu_var(x). This calculates
the address for the instance of the percpu variable of the current processor
based on an offset.
Other use cases are for storing and retrieving data from the current
processors percpu area. __get_cpu_var() can be used as an lvalue when
writing data or on the right side of an assignment.
__get_cpu_var() is defined as :
#define __get_cpu_var(var) (*this_cpu_ptr(&(var)))
__get_cpu_var() always only does an address determination. However, store
and retrieve operations could use a segment prefix (or global register on
other platforms) to avoid the address calculation.
this_cpu_write() and this_cpu_read() can directly take an offset into a
percpu area and use optimized assembly code to read and write per cpu
variables.
This patch converts __get_cpu_var into either an explicit address
calculation using this_cpu_ptr() or into a use of this_cpu operations that
use the offset. Thereby address calculations are avoided and less registers
are used when code is generated.
At the end of the patch set all uses of __get_cpu_var have been removed so
the macro is removed too.
The patch set includes passes over all arches as well. Once these operations
are used throughout then specialized macros can be defined in non -x86
arches as well in order to optimize per cpu access by f.e. using a global
register that may be set to the per cpu base.
Transformations done to __get_cpu_var()
1. Determine the address of the percpu instance of the current processor.
DEFINE_PER_CPU(int, y);
int *x = &__get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(&y);
2. Same as #1 but this time an array structure is involved.
DEFINE_PER_CPU(int, y[20]);
int *x = __get_cpu_var(y);
Converts to
int *x = this_cpu_ptr(y);
3. Retrieve the content of the current processors instance of a per cpu
variable.
DEFINE_PER_CPU(int, y);
int x = __get_cpu_var(y)
Converts to
int x = __this_cpu_read(y);
4. Retrieve the content of a percpu struct
DEFINE_PER_CPU(struct mystruct, y);
struct mystruct x = __get_cpu_var(y);
Converts to
memcpy(&x, this_cpu_ptr(&y), sizeof(x));
5. Assignment to a per cpu variable
DEFINE_PER_CPU(int, y)
__get_cpu_var(y) = x;
Converts to
__this_cpu_write(y, x);
6. Increment/Decrement etc of a per cpu variable
DEFINE_PER_CPU(int, y);
__get_cpu_var(y)++
Converts to
__this_cpu_inc(y)
CC: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Acked-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Christoph Lameter <cl@linux.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
QEMU provides a high-resolution timer and alarm; use this for a clock source and clock event source when available. Signed-off-by: Richard Henderson <rth@twiddle.net>
This allows us to get rid of some hacky code for SMP. Get rid of some cycle counter hackery that's now handled by generic code via clocksource + clock_event_device objects. Signed-off-by: Richard Henderson <rth@twiddle.net>
Don't depend on SMP, just check the number of processors online. This allows a single distribution kernel to use the clocksource when run on a single processor machine. Do depend on whether or not we're using WTINT. Signed-off-by: Richard Henderson <rth@twiddle.net>
Discontinue use of GENERIC_CMOS_UPDATE; rely on the RTC subsystem. The marvel platform requires that the rtc only be touched from the boot cpu. This had been partially implemented with hooks for get/set_rtc_time, but read/update_persistent_clock were not handled. Move the hooks from the machine_vec to a special rtc_class_ops struct. We had read_persistent_clock managing the epoch against which the rtc hw is based, but this didn't apply to get_rtc_time or set_rtc_time. This resulted in incorrect values when hwclock(8) gets involved. Allow the epoch to be set from the kernel command-line, overriding the autodetection, which is doomed to fail in 2020. Further, by implementing the rtc ioctl function, we can expose this epoch to userland. Elide the alarm functions that RTC_DRV_CMOS implements. This was highly questionable on Alpha, since the interrupt is used by the system timer. Signed-off-by: Richard Henderson <rth@twiddle.net>
With the 1024Hz default, we spend 50% of QEMU emulation processing timer interrupts. Signed-off-by: Richard Henderson <rth@twiddle.net>
As introduced in gcc 3.2. Signed-off-by: Matt Turner <mattst88@gmail.com> Signed-off-by: Richard Henderson <rth@twiddle.net>
* 'timers-cleanup-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: mips: Fix i8253 clockevent fallout i8253: Cleanup outb/inb magic arm: Footbridge: Use common i8253 clockevent mips: Use common i8253 clockevent x86: Use common i8253 clockevent i8253: Create common clockevent implementation i8253: Export i8253_lock unconditionally pcpskr: MIPS: Make config dependencies finer grained pcspkr: Cleanup Kconfig dependencies i8253: Move remaining content and delete asm/i8253.h i8253: Consolidate definitions of PIT_LATCH x86: i8253: Consolidate definitions of global_clock_event i8253: Alpha, PowerPC: Remove unused asm/8253pit.h alpha: i8253: Cleanup remaining users of i8253pit.h i8253: Remove I8253_LOCK config i8253: Make pcsp sound driver use the shared i8253_lock i8253: Make pcspkr input driver use the shared i8253_lock i8253: Consolidate all kernel definitions of i8253_lock i8253: Unify all kernel declarations of i8253_lock i8253: Create linux/i8253.h and use it in all 8253 related files
Commit e360adbe29 ("irq_work: Add generic hardirq context
callbacks") fouled up the Alpha bit, not properly naming the
arch specific function that raises the 'self-IPI'.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: stable@kernel.org # 37+
Link: http://lkml.kernel.org/n/tip-gukh0txmql2l4thgrekzzbfy@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>