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author | Tkhai Kirill <tkhai@yandex.ru> | 2012-04-04 19:49:26 (GMT) |
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committer | David S. Miller <davem@davemloft.net> | 2012-04-15 17:28:50 (GMT) |
commit | 62f082830d63cf753ed0dab16f8d3b2d0ffc7f43 (patch) | |
tree | 39770d13d3dbff835eb3500c6a913da5c784fec3 /arch/sparc/kernel/smp_32.c | |
parent | 472bc4f2ad164a5aac2e85d891c4faecfc5d62c4 (diff) | |
download | linux-62f082830d63cf753ed0dab16f8d3b2d0ffc7f43.tar.xz |
sparc32: generic clockevent support
The kernel uses l14 timers as clockevents. l10 timer is used
as clocksource if platform master_l10_counter isn't constantly
zero. The clocksource is continuous, so it's possible to use
high resolution timers. l10 timer is also used as clockevent
on UP configurations.
This realization is for sun4m, sun4d, sun4c, microsparc-IIep
and LEON platforms. The appropriate LEON changes was made by
Konrad Eisele.
In case of sun4m's oneshot mode, profile irq is zeroed in
smp4m_percpu_timer_interrupt(). It is maybe
needless (double, triple etc overflow does nothing).
sun4d is able to have oneshot mode too, but I haven't
any way to test it. So code of its percpu timer handler
is made as much equal to the current code as possible.
The patch is tested on sun4m box in SMP mode by me,
and tested by Konrad on leon in up mode (leon smp
is broken atm - due to other reasons).
Signed-off-by: Tkhai Kirill <tkhai@yandex.ru>
Tested-by: Konrad Eisele <konrad@gaisler.com> [leon up]
[sam: revised patch to provide generic support for leon]
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc/kernel/smp_32.c')
-rw-r--r-- | arch/sparc/kernel/smp_32.c | 21 |
1 files changed, 1 insertions, 20 deletions
diff --git a/arch/sparc/kernel/smp_32.c b/arch/sparc/kernel/smp_32.c index f671e7f..569a8a9 100644 --- a/arch/sparc/kernel/smp_32.c +++ b/arch/sparc/kernel/smp_32.c @@ -301,28 +301,9 @@ void smp_flush_sig_insns(struct mm_struct *mm, unsigned long insn_addr) local_flush_sig_insns(mm, insn_addr); } -extern unsigned int lvl14_resolution; - -/* /proc/profile writes can call this, don't __init it please. */ -static DEFINE_SPINLOCK(prof_setup_lock); - int setup_profiling_timer(unsigned int multiplier) { - int i; - unsigned long flags; - - /* Prevent level14 ticker IRQ flooding. */ - if((!multiplier) || (lvl14_resolution / multiplier) < 500) - return -EINVAL; - - spin_lock_irqsave(&prof_setup_lock, flags); - for_each_possible_cpu(i) { - load_profile_irq(i, lvl14_resolution / multiplier); - prof_multiplier(i) = multiplier; - } - spin_unlock_irqrestore(&prof_setup_lock, flags); - - return 0; + return -EINVAL; } void __init smp_prepare_cpus(unsigned int max_cpus) |