From 1284ba2380b32bf62789b738dbac4d99da463ea1 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Tue, 5 Aug 2014 15:23:23 +0100 Subject: [PATCH] Wallclock time support. Needs much refactoring etc --- arch/arm/include/asm/xen/hypercall.h | 9 +++ arch/arm/xen/enlighten.c | 121 ++++++++++++++++++++++++++++++++++ arch/arm/xen/hypercall.S | 4 +- 3 files changed, 133 insertions(+), 1 deletion(-) diff --git a/arch/arm/include/asm/xen/hypercall.h b/arch/arm/include/asm/xen/hypercall.h index 712b50e..055399a 100644 --- a/arch/arm/include/asm/xen/hypercall.h +++ b/arch/arm/include/asm/xen/hypercall.h @@ -35,6 +35,7 @@ #include #include +#include long privcmd_call(unsigned call, unsigned long a1, unsigned long a2, unsigned long a3, @@ -49,6 +50,14 @@ int HYPERVISOR_memory_op(unsigned int cmd, void *arg); int HYPERVISOR_physdev_op(int cmd, void *arg); int HYPERVISOR_vcpu_op(int cmd, int vcpuid, void *extra_args); int HYPERVISOR_tmem_op(void *arg); +int HYPERVISOR_dom0_op_raw(struct xen_platform_op *platform_op); +static inline int +HYPERVISOR_dom0_op(struct xen_platform_op *platform_op) +{ + platform_op->interface_version = XENPF_INTERFACE_VERSION; + return HYPERVISOR_dom0_op_raw(platform_op); +} + int HYPERVISOR_multicall(struct multicall_entry *calls, uint32_t nr); static inline int diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 1e63243..0364987 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include #include @@ -24,6 +25,7 @@ #include #include #include +#include #include @@ -219,6 +221,122 @@ static irqreturn_t xen_arm_callback(int irq, void *arg) return IRQ_HANDLED; } +unsigned long xen_clocksource_read(void) +{ + unsigned long val = 0; + /* XXX arch timer? Error handling etc etc */ + if (read_current_timer(&val) < 0) + printk("read_current_timer failed?\n"); + return val; +} + +void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock, + struct pvclock_vcpu_time_info *vcpu_time, + struct timespec *ts) +{ + u32 version; + u64 delta; + struct timespec now; + + /* get wallclock at system boot */ + do { + version = wall_clock->version; + rmb(); /* fetch version before time */ + now.tv_sec = wall_clock->sec; + now.tv_nsec = wall_clock->nsec; + rmb(); /* fetch time before checking version */ + } while ((wall_clock->version & 1) || (version != wall_clock->version)); + + //delta = pvclock_clocksource_read(vcpu_time); /* time since system boot */ + delta = xen_clocksource_read(); + delta += now.tv_sec * (u64)NSEC_PER_SEC + now.tv_nsec; + + now.tv_nsec = do_div(delta, NSEC_PER_SEC); + now.tv_sec = delta; + + set_normalized_timespec(ts, now.tv_sec, now.tv_nsec); +} + +static void xen_read_wallclock(struct timespec *ts) +{ + struct shared_info *s = HYPERVISOR_shared_info; + struct pvclock_wall_clock *wall_clock = &(s->wc); + struct pvclock_vcpu_time_info *vcpu_time; + + vcpu_time = &get_cpu_var(xen_vcpu)->time; + pvclock_read_wallclock(wall_clock, vcpu_time, ts); + put_cpu_var(xen_vcpu); +} + +/* Parts could be common with x86? */ +static int xen_pvclock_gtod_notify(struct notifier_block *nb, + unsigned long was_set, void *priv) +{ + /* Protected by the calling core code serialization */ + static struct timespec next_sync; + + struct xen_platform_op op; + struct timespec now; + + now = __current_kernel_time(); + + /* + * We only take the expensive HV call when the clock was set + * or when the 11 minutes RTC synchronization time elapsed. + */ + if (!was_set && timespec_compare(&now, &next_sync) < 0) + return NOTIFY_OK; + + op.cmd = XENPF_settime; + op.u.settime.secs = now.tv_sec; + op.u.settime.nsecs = now.tv_nsec; + op.u.settime.system_time = xen_clocksource_read(); + printk("GTOD: Setting to %ld.%ld at %lld\n", + (long)op.u.settime.secs, + (long)op.u.settime.nsecs, + (long long)op.u.settime.system_time); + (void)HYPERVISOR_dom0_op(&op); + + /* + * Move the next drift compensation time 11 minutes + * ahead. That's emulating the sync_cmos_clock() update for + * the hardware RTC. + */ + next_sync = now; + next_sync.tv_sec += 11 * 60; + + return NOTIFY_OK; +} + +static struct notifier_block xen_pvclock_gtod_notifier = { + .notifier_call = xen_pvclock_gtod_notify, +}; + +static void __init xen_time_init(void) +{ + //int cpu = smp_processor_id(); + struct timespec tp; + + /* Set initial system time with full resolution */ + xen_read_wallclock(&tp); + do_settimeofday(&tp); + + printk("INITIAL TIME %ld.%ld\n", + (long)tp.tv_sec, + (long)tp.tv_nsec); + { + struct shared_info *s = HYPERVISOR_shared_info; + struct pvclock_wall_clock *wall_clock = &(s->wc); + struct pvclock_vcpu_time_info *vcpu_time; + printk("SHARED INFO TIME %ld.%ld\n", + (long)wall_clock->sec, + (long)wall_clock->nsec); + } + + if (xen_initial_domain()) + pvclock_gtod_register_notifier(&xen_pvclock_gtod_notifier); +} + /* * see Documentation/devicetree/bindings/arm/xen.txt for the * documentation of the Xen Device Tree format. @@ -323,6 +441,8 @@ static int __init xen_guest_init(void) register_cpu_notifier(&xen_cpu_notifier); + xen_time_init(); + return 0; } early_initcall(xen_guest_init); @@ -359,4 +479,5 @@ EXPORT_SYMBOL_GPL(HYPERVISOR_physdev_op); EXPORT_SYMBOL_GPL(HYPERVISOR_vcpu_op); EXPORT_SYMBOL_GPL(HYPERVISOR_tmem_op); EXPORT_SYMBOL_GPL(HYPERVISOR_multicall); +EXPORT_SYMBOL_GPL(HYPERVISOR_dom0_op_raw); EXPORT_SYMBOL_GPL(privcmd_call); diff --git a/arch/arm/xen/hypercall.S b/arch/arm/xen/hypercall.S index 44e3a5f..d3bf35e 100644 --- a/arch/arm/xen/hypercall.S +++ b/arch/arm/xen/hypercall.S @@ -78,7 +78,6 @@ ENTRY(HYPERVISOR_##hypercall) \ ENDPROC(HYPERVISOR_##hypercall) .text - HYPERCALL2(xen_version); HYPERCALL3(console_io); HYPERCALL3(grant_table_op); @@ -91,6 +90,9 @@ HYPERCALL3(vcpu_op); HYPERCALL1(tmem_op); HYPERCALL2(multicall); +#define __HYPERVISOR_dom0_op_raw __HYPERVISOR_dom0_op /* Hack to allow setting interface version from C wrapper */ +HYPERCALL1(dom0_op_raw);/*XXX legacy name for what is now platform_op, used by x86 too*/ + ENTRY(privcmd_call) stmdb sp!, {r4} mov r12, r0 -- 1.7.10.4