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authorLinus Torvalds <torvalds@linux-foundation.org>2009-06-15 09:32:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-15 09:32:52 -0700
commit0fa213310cd8fa7a51071cdcf130e26fa56e9549 (patch)
tree2a7e5cc33c8938ec82604a99c3797a3132fd91ec /arch/powerpc/kernel/time.c
parentd3bf80bff13597004b5724ee4549cd68eb0badf0 (diff)
parentbc47ab0241c7c86da4f5e5f82fbca7d45387c18d (diff)
Merge branch 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (103 commits) powerpc: Fix bug in move of altivec code to vector.S powerpc: Add support for swiotlb on 32-bit powerpc/spufs: Remove unused error path powerpc: Fix warning when printing a resource_size_t powerpc/xmon: Remove unused variable in xmon.c powerpc/pseries: Fix warnings when printing resource_size_t powerpc: Shield code specific to 64-bit server processors powerpc: Separate PACA fields for server CPUs powerpc: Split exception handling out of head_64.S powerpc: Introduce CONFIG_PPC_BOOK3S powerpc: Move VMX and VSX asm code to vector.S powerpc: Set init_bootmem_done on NUMA platforms as well powerpc/mm: Fix a AB->BA deadlock scenario with nohash MMU context lock powerpc/mm: Fix some SMP issues with MMU context handling powerpc: Add PTRACE_SINGLEBLOCK support fbdev: Add PLB support and cleanup DCR in xilinxfb driver. powerpc/virtex: Add ml510 reference design device tree powerpc/virtex: Add Xilinx ML510 reference design support powerpc/virtex: refactor intc driver and add support for i8259 cascading powerpc/virtex: Add support for Xilinx PCI host bridge ...
Diffstat (limited to 'arch/powerpc/kernel/time.c')
-rw-r--r--arch/powerpc/kernel/time.c21
1 files changed, 18 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 48571ac56fb..bee1443da76 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -109,7 +109,7 @@ static void decrementer_set_mode(enum clock_event_mode mode,
static struct clock_event_device decrementer_clockevent = {
.name = "decrementer",
.rating = 200,
- .shift = 16,
+ .shift = 0, /* To be filled in */
.mult = 0, /* To be filled in */
.irq = 0,
.set_next_event = decrementer_set_next_event,
@@ -843,6 +843,22 @@ static void decrementer_set_mode(enum clock_event_mode mode,
decrementer_set_next_event(DECREMENTER_MAX, dev);
}
+static void __init setup_clockevent_multiplier(unsigned long hz)
+{
+ u64 mult, shift = 32;
+
+ while (1) {
+ mult = div_sc(hz, NSEC_PER_SEC, shift);
+ if (mult && (mult >> 32UL) == 0UL)
+ break;
+
+ shift--;
+ }
+
+ decrementer_clockevent.shift = shift;
+ decrementer_clockevent.mult = mult;
+}
+
static void register_decrementer_clockevent(int cpu)
{
struct clock_event_device *dec = &per_cpu(decrementers, cpu).event;
@@ -860,8 +876,7 @@ static void __init init_decrementer_clockevent(void)
{
int cpu = smp_processor_id();
- decrementer_clockevent.mult = div_sc(ppc_tb_freq, NSEC_PER_SEC,
- decrementer_clockevent.shift);
+ setup_clockevent_multiplier(ppc_tb_freq);
decrementer_clockevent.max_delta_ns =
clockevent_delta2ns(DECREMENTER_MAX, &decrementer_clockevent);
decrementer_clockevent.min_delta_ns =