diff options
Diffstat (limited to 'drivers/hv/hv.c')
| -rw-r--r-- | drivers/hv/hv.c | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index 3e4235c7a47f..50e51a51ff8b 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -28,7 +28,9 @@ #include <linux/hyperv.h> #include <linux/version.h> #include <linux/interrupt.h> +#include <linux/clockchips.h> #include <asm/hyperv.h> +#include <asm/mshyperv.h> #include "hyperv_vmbus.h" /* The one and only */ @@ -37,6 +39,10 @@ struct hv_context hv_context = { .hypercall_page = NULL, }; +#define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */ +#define HV_MAX_MAX_DELTA_TICKS 0xffffffff +#define HV_MIN_DELTA_TICKS 1 + /* * query_hypervisor_info - Get version info of the windows hypervisor */ @@ -144,6 +150,8 @@ int hv_init(void) sizeof(int) * NR_CPUS); memset(hv_context.event_dpc, 0, sizeof(void *) * NR_CPUS); + memset(hv_context.clk_evt, 0, + sizeof(void *) * NR_CPUS); max_leaf = query_hypervisor_info(); @@ -258,10 +266,63 @@ u16 hv_signal_event(void *con_id) return status; } +static int hv_ce_set_next_event(unsigned long delta, + struct clock_event_device *evt) +{ + cycle_t current_tick; + + WARN_ON(evt->mode != CLOCK_EVT_MODE_ONESHOT); + + rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick); + current_tick += delta; + wrmsrl(HV_X64_MSR_STIMER0_COUNT, current_tick); + return 0; +} + +static void hv_ce_setmode(enum clock_event_mode mode, + struct clock_event_device *evt) +{ + union hv_timer_config timer_cfg; + + switch (mode) { + case CLOCK_EVT_MODE_PERIODIC: + /* unsupported */ + break; + + case CLOCK_EVT_MODE_ONESHOT: + timer_cfg.enable = 1; + timer_cfg.auto_enable = 1; + timer_cfg.sintx = VMBUS_MESSAGE_SINT; + wrmsrl(HV_X64_MSR_STIMER0_CONFIG, timer_cfg.as_uint64); + break; + + case CLOCK_EVT_MODE_UNUSED: + case CLOCK_EVT_MODE_SHUTDOWN: + wrmsrl(HV_X64_MSR_STIMER0_COUNT, 0); + wrmsrl(HV_X64_MSR_STIMER0_CONFIG, 0); + break; + case CLOCK_EVT_MODE_RESUME: + break; + } +} + +static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu) +{ + dev->name = "Hyper-V clockevent"; + dev->features = CLOCK_EVT_FEAT_ONESHOT; + dev->cpumask = cpumask_of(cpu); + dev->rating = 1000; + dev->owner = THIS_MODULE; + + dev->set_mode = hv_ce_setmode; + dev->set_next_event = hv_ce_set_next_event; +} + int hv_synic_alloc(void) { size_t size = sizeof(struct tasklet_struct); + size_t ced_size = sizeof(struct clock_event_device); int cpu; for_each_online_cpu(cpu) { @@ -272,6 +333,13 @@ int hv_synic_alloc(void) } tasklet_init(hv_context.event_dpc[cpu], vmbus_on_event, cpu); + hv_context.clk_evt[cpu] = kzalloc(ced_size, GFP_ATOMIC); + if (hv_context.clk_evt[cpu] == NULL) { + pr_err("Unable to allocate clock event device\n"); + goto err; + } + hv_init_clockevent_device(hv_context.clk_evt[cpu], cpu); + hv_context.synic_message_page[cpu] = (void *)get_zeroed_page(GFP_ATOMIC); @@ -305,6 +373,7 @@ err: static void hv_synic_free_cpu(int cpu) { kfree(hv_context.event_dpc[cpu]); + kfree(hv_context.clk_evt[cpu]); if (hv_context.synic_event_page[cpu]) free_page((unsigned long)hv_context.synic_event_page[cpu]); if (hv_context.synic_message_page[cpu]) @@ -388,6 +457,15 @@ void hv_synic_init(void *arg) hv_context.vp_index[cpu] = (u32)vp_index; INIT_LIST_HEAD(&hv_context.percpu_list[cpu]); + + /* + * Register the per-cpu clockevent source. + */ + if (ms_hyperv.features & HV_X64_MSR_SYNTIMER_AVAILABLE) + clockevents_config_and_register(hv_context.clk_evt[cpu], + HV_TIMER_FREQUENCY, + HV_MIN_DELTA_TICKS, + HV_MAX_MAX_DELTA_TICKS); return; } |