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clocksource/drivers/hyperv: add data structure for reference TSC MSR

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Add a data structure to represent the reference TSC MSR similar to
other MSRs. This simplifies the code for updating the MSR.

Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20221027095729.1676394-2-anrayabh@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
This commit is contained in:
Anirudh Rayabharam 2022-10-27 15:27:28 +05:30 committed by Wei Liu
parent 99632e3dbe
commit 4ad1aa5712
2 changed files with 24 additions and 14 deletions
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29
drivers/clocksource/hyperv_timer.c
View File

@ -21,6 +21,7 @@
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/acpi.h>
#include <linux/hyperv.h>
#include <clocksource/hyperv_timer.h>
#include <asm/hyperv-tlfs.h>
#include <asm/mshyperv.h>
@ -395,25 +396,25 @@ static u64 notrace read_hv_sched_clock_tsc(void)
static void suspend_hv_clock_tsc(struct clocksource *arg)
{
u64 tsc_msr;
union hv_reference_tsc_msr tsc_msr;
/* Disable the TSC page */
tsc_msr = hv_get_register(HV_REGISTER_REFERENCE_TSC);
tsc_msr &= ~BIT_ULL(0);
hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr);
tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
tsc_msr.enable = 0;
hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
}
static void resume_hv_clock_tsc(struct clocksource *arg)
{
phys_addr_t phys_addr = virt_to_phys(&tsc_pg);
u64 tsc_msr;
union hv_reference_tsc_msr tsc_msr;
/* Re-enable the TSC page */
tsc_msr = hv_get_register(HV_REGISTER_REFERENCE_TSC);
tsc_msr &= GENMASK_ULL(11, 0);
tsc_msr |= BIT_ULL(0) | (u64)phys_addr;
hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr);
tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
tsc_msr.enable = 1;
tsc_msr.pfn = HVPFN_DOWN(phys_addr);
hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
}
#ifdef HAVE_VDSO_CLOCKMODE_HVCLOCK
@ -495,7 +496,7 @@ static __always_inline void hv_setup_sched_clock(void *sched_clock) {}
static bool __init hv_init_tsc_clocksource(void)
{
u64 tsc_msr;
union hv_reference_tsc_msr tsc_msr;
phys_addr_t phys_addr;
if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE))
@ -530,10 +531,10 @@ static bool __init hv_init_tsc_clocksource(void)
* (which already has at least the low 12 bits set to zero since
* it is page aligned). Also set the "enable" bit, which is bit 0.
*/
tsc_msr = hv_get_register(HV_REGISTER_REFERENCE_TSC);
tsc_msr &= GENMASK_ULL(11, 0);
tsc_msr = tsc_msr | 0x1 | (u64)phys_addr;
hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr);
tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
tsc_msr.enable = 1;
tsc_msr.pfn = HVPFN_DOWN(phys_addr);
hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);

9
include/asm-generic/hyperv-tlfs.h
View File

@ -102,6 +102,15 @@ struct ms_hyperv_tsc_page {
volatile s64 tsc_offset;
} __packed;
union hv_reference_tsc_msr {
u64 as_uint64;
struct {
u64 enable:1;
u64 reserved:11;
u64 pfn:52;
} __packed;
};
/*
* The guest OS needs to register the guest ID with the hypervisor.
* The guest ID is a 64 bit entity and the structure of this ID is