diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2019-06-23 15:24:01 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2019-06-28 00:57:23 +0200 |
| commit | af5a1dadf3fcf673906af1a1129b2b7528494ee5 (patch) | |
| tree | be1ada03a31b6772eb5688f61c9297dc76ca3abb /arch/x86/kernel/hpet.c | |
| parent | 9e16e4933e48819a259b8967e72e5765349953b1 (diff) | |
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 <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/20190623132436.002758910@linutronix.de
Diffstat (limited to 'arch/x86/kernel/hpet.c')
| -rw-r--r-- | arch/x86/kernel/hpet.c | 17 |
1 files changed, 17 insertions, 0 deletions
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 */ |