diff options
Diffstat (limited to 'drivers/char')
| -rw-r--r-- | drivers/char/uv_mmtimer.c | 18 |
1 files changed, 11 insertions, 7 deletions
diff --git a/drivers/char/uv_mmtimer.c b/drivers/char/uv_mmtimer.c index 867b67be9f0a..c7072ba14f48 100644 --- a/drivers/char/uv_mmtimer.c +++ b/drivers/char/uv_mmtimer.c @@ -89,13 +89,17 @@ static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd, switch (cmd) { case MMTIMER_GETOFFSET: /* offset of the counter */ /* - * UV RTC register is on its own page + * Starting with HUB rev 2.0, the UV RTC register is + * replicated across all cachelines of it's own page. + * This allows faster simultaneous reads from a given socket. + * + * The offset returned is in 64 bit units. */ - if (PAGE_SIZE <= (1 << 16)) - ret = ((UV_LOCAL_MMR_BASE | UVH_RTC) & (PAGE_SIZE-1)) - / 8; + if (uv_get_min_hub_revision_id() == 1) + ret = 0; else - ret = -ENOSYS; + ret = ((uv_blade_processor_id() * L1_CACHE_BYTES) % + PAGE_SIZE) / 8; break; case MMTIMER_GETRES: /* resolution of the clock in 10^-15 s */ @@ -115,8 +119,8 @@ static long uv_mmtimer_ioctl(struct file *file, unsigned int cmd, ret = hweight64(UVH_RTC_REAL_TIME_CLOCK_MASK); break; - case MMTIMER_MMAPAVAIL: /* can we mmap the clock into userspace? */ - ret = (PAGE_SIZE <= (1 << 16)) ? 1 : 0; + case MMTIMER_MMAPAVAIL: + ret = 1; break; case MMTIMER_GETCOUNTER: |