Commit-ID: af5a1dadf3fcf673906af1a1129b2b7528494ee5 Gitweb: https://git.kernel.org/tip/af5a1dadf3fcf673906af1a1129b2b7528494ee5 Author: Thomas Gleixner <t...@linutronix.de> AuthorDate: Sun, 23 Jun 2019 15:24:01 +0200 Committer: Thomas Gleixner <t...@linutronix.de> CommitDate: Fri, 28 Jun 2019 00:57:23 +0200
x86/hpet: Add function to select a /dev/hpet channel If CONFIG_HPET=y is enabled the x86 specific HPET code should reserve at least one channel for the /dev/hpet character device, so that not all channels are absorbed for per CPU clockevent devices. Create a function to assign HPET_MODE_DEVICE so the rework of the clockevents allocation code can utilize the mode information instead of reducing the number of evaluated channels by #ifdef hackery. The function is not yet used, but provided as a separate patch for ease of review. It will be used when the rework of the clockevent selection takes place. Signed-off-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: Ingo Molnar <mi...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Ricardo Neri <ricardo.neri-calde...@linux.intel.com> Cc: Ashok Raj <ashok....@intel.com> Cc: Andi Kleen <andi.kl...@intel.com> Cc: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com> Cc: Stephane Eranian <eran...@google.com> Cc: Ravi Shankar <ravi.v.shan...@intel.com> Link: https://lkml.kernel.org/r/20190623132436.002758...@linutronix.de --- arch/x86/kernel/hpet.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c index 3a8ec363d569..640ff75cc523 100644 --- a/arch/x86/kernel/hpet.c +++ b/arch/x86/kernel/hpet.c @@ -228,8 +228,25 @@ static void __init hpet_reserve_platform_timers(void) hpet_alloc(&hd); } + +static void __init hpet_select_device_channel(void) +{ + int i; + + for (i = 0; i < hpet_base.nr_channels; i++) { + struct hpet_channel *hc = hpet_base.channels + i; + + /* Associate the first unused channel to /dev/hpet */ + if (hc->mode == HPET_MODE_UNUSED) { + hc->mode = HPET_MODE_DEVICE; + return; + } + } +} + #else static inline void hpet_reserve_platform_timers(void) { } +static inline void hpet_select_device_channel(void) {} #endif /* Common HPET functions */
