On Wed, Jan 18, 2017 at 04:45:04PM -0700, k...@exchange.microsoft.com wrote:
> From: K. Y. Srinivasan <k...@microsoft.com>
>
> As part of the effort to separate out architecture specific code,
> consolidate all Hyper-V specific clocksource code to an architecture
> specific code.
>
> Signed-off-by: K. Y. Srinivasan <k...@microsoft.com>
> ---
> arch/x86/hyperv/hv_init.c | 104
> +++++++++++++++++++++++++++++++++++++++
> arch/x86/include/asm/mshyperv.h | 12 +++++
> arch/x86/kernel/cpu/mshyperv.c | 23 ---------
> drivers/hv/hv.c | 95 -----------------------------------
> drivers/hv/hyperv_vmbus.h | 8 ---
> 5 files changed, 116 insertions(+), 126 deletions(-)
>
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index b5c8e04..691dfaf 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -24,6 +24,79 @@
> #include <linux/version.h>
> #include <linux/vmalloc.h>
> #include <linux/mm.h>
> +#include <linux/clockchips.h>
> +
> +
> +#ifdef CONFIG_X86_64
> +
> +static struct ms_hyperv_tsc_page *tsc_pg;
> +
> +static u64 read_hv_clock_tsc(struct clocksource *arg)
> +{
> + u64 current_tick;
> +
> + if (tsc_pg->tsc_sequence != 0) {
> + /*
> + * Use the tsc page to compute the value.
> + */
> +
> + while (1) {
> + u64 tmp;
> + u32 sequence = tsc_pg->tsc_sequence;
> + u64 cur_tsc;
> + u64 scale = tsc_pg->tsc_scale;
> + s64 offset = tsc_pg->tsc_offset;
> +
> + rdtscll(cur_tsc);
> + /* current_tick = ((cur_tsc *scale) >> 64) + offset */
> + asm("mulq %3"
> + : "=d" (current_tick), "=a" (tmp)
> + : "a" (cur_tsc), "r" (scale));
> +
> + current_tick += offset;
> + if (tsc_pg->tsc_sequence == sequence)
> + return current_tick;
> +
> + if (tsc_pg->tsc_sequence != 0)
> + continue;
> + /*
> + * Fallback using MSR method.
> + */
> + break;
> + }
> + }
> + rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
> + return current_tick;
> +}
> +
> +static struct clocksource hyperv_cs_tsc = {
> + .name = "hyperv_clocksource_tsc_page",
> + .rating = 400,
> + .read = read_hv_clock_tsc,
> + .mask = CLOCKSOURCE_MASK(64),
> + .flags = CLOCK_SOURCE_IS_CONTINUOUS,
> +};
> +#endif
> +
> +static u64 read_hv_clock_msr(struct clocksource *arg)
> +{
> + u64 current_tick;
> + /*
> + * Read the partition counter to get the current tick count. This count
> + * is set to 0 when the partition is created and is incremented in
> + * 100 nanosecond units.
> + */
> + rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
> + return current_tick;
> +}
> +
> +static struct clocksource hyperv_cs_msr = {
> + .name = "hyperv_clocksource_msr",
> + .rating = 400,
> + .read = read_hv_clock_msr,
> + .mask = CLOCKSOURCE_MASK(64),
> + .flags = CLOCK_SOURCE_IS_CONTINUOUS,
> +};
>
> static void *hypercall_pg;
> /*
> @@ -31,6 +104,7 @@
> * hypervisor has been detected.
> *
> * 1. Setup the hypercall page.
> + * 2. Register Hyper-V specific clocksource.
> */
> void hyperv_init(void)
> {
> @@ -58,6 +132,36 @@ void hyperv_init(void)
> hypercall_msr.enable = 1;
> hypercall_msr.guest_physical_address = vmalloc_to_pfn(hypercall_pg);
> wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
> +
> + /*
> + * Register Hyper-V specific clocksource.
> + */
> +#ifdef CONFIG_X86_64
> + if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
> + union hv_x64_msr_hypercall_contents tsc_msr;
> +
> + tsc_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
> + if (!tsc_pg)
> + clocksource_register_hz(&hyperv_cs_msr,
> NSEC_PER_SEC/100);
> + return;
There's a reason you always test-build your patches and pay attention to
the warnings!
How did this pass your tests?
I've stopped applying patches here.
greg k-h
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