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authorTianyu Lan <Tianyu.Lan@microsoft.com>2019-08-14 14:32:15 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-08-23 16:59:53 +0200
commitadb87ff4f96c9700718e09c97a804124d5cd61ff (patch)
tree477a173e4b350b879c369d07e2af20f9bdfefff7 /drivers/clocksource
parentposix-cpu-timers: Remove tsk argument from run_posix_cpu_timers() (diff)
downloadlinux-adb87ff4f96c9700718e09c97a804124d5cd61ff.tar.xz
linux-adb87ff4f96c9700718e09c97a804124d5cd61ff.zip
clocksource/drivers/hyperv: Allocate Hyper-V TSC page statically
Prepare to add Hyper-V sched clock callback and move Hyper-V Reference TSC initialization much earlier in the boot process. Earlier initialization is needed so that it happens while the timestamp value is still 0 and no discontinuity in the timestamp will occur when pv_ops.time.sched_clock calculates its offset. The earlier initialization requires that the Hyper-V TSC page be allocated statically instead of with vmalloc(), so fixup the references to the TSC page and the method of getting its physical address. Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lkml.kernel.org/r/20190814123216.32245-2-Tianyu.Lan@microsoft.com
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/hyperv_timer.c12
1 files changed, 4 insertions, 8 deletions
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index ba2c79e6a0ee..432aa331df04 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -214,17 +214,17 @@ EXPORT_SYMBOL_GPL(hyperv_cs);
#ifdef CONFIG_HYPERV_TSCPAGE
-static struct ms_hyperv_tsc_page *tsc_pg;
+static struct ms_hyperv_tsc_page tsc_pg __aligned(PAGE_SIZE);
struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
{
- return tsc_pg;
+ return &tsc_pg;
}
EXPORT_SYMBOL_GPL(hv_get_tsc_page);
static u64 notrace read_hv_sched_clock_tsc(void)
{
- u64 current_tick = hv_read_tsc_page(tsc_pg);
+ u64 current_tick = hv_read_tsc_page(&tsc_pg);
if (current_tick == U64_MAX)
hv_get_time_ref_count(current_tick);
@@ -280,12 +280,8 @@ static bool __init hv_init_tsc_clocksource(void)
if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE))
return false;
- tsc_pg = vmalloc(PAGE_SIZE);
- if (!tsc_pg)
- return false;
-
hyperv_cs = &hyperv_cs_tsc;
- phys_addr = page_to_phys(vmalloc_to_page(tsc_pg));
+ phys_addr = virt_to_phys(&tsc_pg);
/*
* The Hyper-V TLFS specifies to preserve the value of reserved