diff options
author | Tim Deegan <tim@xen.org> | 2013-03-28 11:27:31 +0000 |
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committer | Tim Deegan <tim@xen.org> | 2013-03-29 09:43:25 +0000 |
commit | 527824f41f5fac9cba3d4441b2e73d3118d98837 (patch) | |
tree | 598827e17c7aa6201833e7b52ed6e49a6c271fc9 /xen/arch/x86/hvm/rtc.c | |
parent | ecaa2629f2eb90048a18bcc1df430328cc0371be (diff) | |
download | xen-527824f41f5fac9cba3d4441b2e73d3118d98837.tar.gz xen-527824f41f5fac9cba3d4441b2e73d3118d98837.tar.bz2 xen-527824f41f5fac9cba3d4441b2e73d3118d98837.zip |
x86/hvm: Centralize and simplify the RTC IRQ logic.
This keeps the behaviour of strobing the IRQ line every time any RTC
interrupt source is raised. I rather suspect (based on the behaviour
of the MC146818A RTC) that we ought to be suppressing all subsequent
interrupts whenever RTC_IRQF is set, but this way avoids making
guest-visible changes.
Signed-off-by: Tim Deegan <tim@xen.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>
Diffstat (limited to 'xen/arch/x86/hvm/rtc.c')
-rw-r--r-- | xen/arch/x86/hvm/rtc.c | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/xen/arch/x86/hvm/rtc.c b/xen/arch/x86/hvm/rtc.c index 88cacd1caf..26ab12c7f3 100644 --- a/xen/arch/x86/hvm/rtc.c +++ b/xen/arch/x86/hvm/rtc.c @@ -50,14 +50,25 @@ static void rtc_set_time(RTCState *s); static inline int from_bcd(RTCState *s, int a); static inline int convert_hour(RTCState *s, int hour); -static void rtc_toggle_irq(RTCState *s) +static void rtc_update_irq(RTCState *s) { struct domain *d = vrtc_domain(s); + uint8_t irqf; ASSERT(spin_is_locked(&s->lock)); - s->hw.cmos_data[RTC_REG_C] |= RTC_IRQF; + + /* IRQ is raised if any source is both raised & enabled */ + irqf = (s->hw.cmos_data[RTC_REG_B] + & s->hw.cmos_data[RTC_REG_C] + & (RTC_PF|RTC_AF|RTC_UF)) + ? RTC_IRQF : 0; + + s->hw.cmos_data[RTC_REG_C] &= ~RTC_IRQF; + s->hw.cmos_data[RTC_REG_C] |= irqf; + hvm_isa_irq_deassert(d, RTC_IRQ); - hvm_isa_irq_assert(d, RTC_IRQ); + if ( irqf ) + hvm_isa_irq_assert(d, RTC_IRQ); } void rtc_periodic_interrupt(void *opaque) @@ -68,8 +79,7 @@ void rtc_periodic_interrupt(void *opaque) if ( !(s->hw.cmos_data[RTC_REG_C] & RTC_PF) ) { s->hw.cmos_data[RTC_REG_C] |= RTC_PF; - if ( s->hw.cmos_data[RTC_REG_B] & RTC_PIE ) - rtc_toggle_irq(s); + rtc_update_irq(s); } else if ( ++(s->pt_dead_ticks) >= 10 ) { @@ -187,8 +197,7 @@ static void rtc_update_timer2(void *opaque) { s->hw.cmos_data[RTC_REG_C] |= RTC_UF; s->hw.cmos_data[RTC_REG_A] &= ~RTC_UIP; - if ((s->hw.cmos_data[RTC_REG_B] & RTC_UIE)) - rtc_toggle_irq(s); + rtc_update_irq(s); check_update_timer(s); } spin_unlock(&s->lock); @@ -378,9 +387,7 @@ static void rtc_alarm_cb(void *opaque) if (!(s->hw.cmos_data[RTC_REG_B] & RTC_SET)) { s->hw.cmos_data[RTC_REG_C] |= RTC_AF; - /* alarm interrupt */ - if (s->hw.cmos_data[RTC_REG_B] & RTC_AIE) - rtc_toggle_irq(s); + rtc_update_irq(s); alarm_timer_update(s); } spin_unlock(&s->lock); @@ -390,7 +397,7 @@ static int rtc_ioport_write(void *opaque, uint32_t addr, uint32_t data) { RTCState *s = opaque; struct domain *d = vrtc_domain(s); - uint32_t orig, mask; + uint32_t orig; spin_lock(&s->lock); @@ -464,15 +471,8 @@ static int rtc_ioport_write(void *opaque, uint32_t addr, uint32_t data) /* * If the interrupt is already set when the interrupt becomes * enabled, raise an interrupt immediately. - * NB: RTC_{A,P,U}IE == RTC_{A,P,U}F respectively. */ - for ( mask = RTC_UIE; mask <= RTC_PIE; mask <<= 1 ) - if ( (data & mask) && !(orig & mask) && - (s->hw.cmos_data[RTC_REG_C] & mask) ) - { - rtc_toggle_irq(s); - break; - } + rtc_update_irq(s); s->hw.cmos_data[RTC_REG_B] = data; if ( (data ^ orig) & RTC_SET ) check_update_timer(s); @@ -628,8 +628,8 @@ static uint32_t rtc_ioport_read(RTCState *s, uint32_t addr) break; case RTC_REG_C: ret = s->hw.cmos_data[s->hw.cmos_index]; - hvm_isa_irq_deassert(vrtc_domain(s), RTC_IRQ); s->hw.cmos_data[RTC_REG_C] = 0x00; + rtc_update_irq(s); check_update_timer(s); alarm_timer_update(s); rtc_timer_update(s); |