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Drivers: hv: vmbus: Consolidate all Hyper-V specific clocksource code

Browse source 
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 <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
K. Y. Srinivasan 2017-01-19 11:51:46 -07:00 committed by Greg Kroah-Hartman
parent 669c256cb9
commit 63ed4e0c67
5 changed files with 117 additions and 126 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

105
arch/x86/hyperv/hv_init.c
View file

@ -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 @@ static void *hypercall_pg;
* hypervisor has been detected.
*
* 1. Setup the hypercall page.
* 2. Register Hyper-V specific clocksource.
*/
void hyperv_init(void)
{
@ -58,6 +132,37 @@ 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;
}
rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
tsc_msr.enable = 1;
tsc_msr.guest_physical_address = vmalloc_to_pfn(tsc_pg);
wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
return;
}
#endif
/*
* For 32 bit guests just use the MSR based mechanism for reading
* the partition counter.
*/
if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
}
/*

12
arch/x86/include/asm/mshyperv.h
View file

@ -25,6 +25,18 @@ union hv_x64_msr_hypercall_contents {
};
};
/*
* TSC page layout.
*/
struct ms_hyperv_tsc_page {
volatile u32 tsc_sequence;
u32 reserved1;
volatile u64 tsc_scale;
volatile s64 tsc_offset;
u64 reserved2[509];
};
/*
* 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

23
arch/x86/kernel/cpu/mshyperv.c
View file

@ -133,26 +133,6 @@ static uint32_t __init ms_hyperv_platform(void)
return 0;
}
static u64 read_hv_clock(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 = {
.name = "hyperv_clocksource",
.rating = 400, /* use this when running on Hyperv*/
.read = read_hv_clock,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static unsigned char hv_get_nmi_reason(void)
{
return 0;
@ -208,9 +188,6 @@ static void __init ms_hyperv_init_platform(void)
"hv_nmi_unknown");
#endif
if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
#ifdef CONFIG_X86_IO_APIC
no_timer_check = 1;
#endif

95
drivers/hv/hv.c
View file

@ -87,56 +87,6 @@ static int query_hypervisor_info(void)
return max_leaf;
}
#ifdef CONFIG_X86_64
static u64 read_hv_clock_tsc(struct clocksource *arg)
{
u64 current_tick;
struct ms_hyperv_tsc_page *tsc_pg = hv_context.tsc_page;
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 = 425,
.read = read_hv_clock_tsc,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
#endif
/*
* hv_init - Main initialization routine.
*
@ -171,29 +121,7 @@ int hv_init(void)
if (!hypercall_msr.enable)
return -ENOTSUPP;
#ifdef CONFIG_X86_64
if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
union hv_x64_msr_hypercall_contents tsc_msr;
void *va_tsc;
va_tsc = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
if (!va_tsc)
goto cleanup;
hv_context.tsc_page = va_tsc;
rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
tsc_msr.enable = 1;
tsc_msr.guest_physical_address = vmalloc_to_pfn(va_tsc);
wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
}
#endif
return 0;
cleanup:
return -ENOTSUPP;
}
/*
@ -204,29 +132,6 @@ int hv_init(void)
void hv_cleanup(bool crash)
{
#ifdef CONFIG_X86_64
union hv_x64_msr_hypercall_contents hypercall_msr;
/*
* Cleanup the TSC page based CS.
*/
if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
/*
* Crash can happen in an interrupt context and unregistering
* a clocksource is impossible and redundant in this case.
*/
if (!oops_in_progress) {
clocksource_change_rating(&hyperv_cs_tsc, 10);
clocksource_unregister(&hyperv_cs_tsc);
}
hypercall_msr.as_uint64 = 0;
wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
if (!crash) {
vfree(hv_context.tsc_page);
hv_context.tsc_page = NULL;
}
}
#endif
}
/*

8
drivers/hv/hyperv_vmbus.h
View file

@ -416,14 +416,6 @@ struct hv_context {
extern struct hv_context hv_context;
struct ms_hyperv_tsc_page {
volatile u32 tsc_sequence;
u32 reserved1;
volatile u64 tsc_scale;
volatile s64 tsc_offset;
u64 reserved2[509];
};
struct hv_ring_buffer_debug_info {
u32 current_interrupt_mask;
u32 current_read_index;