From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tim Deegan Subject: [PATCH 4/4] x86/hvm: Centralize and simplify the RTC IRQ logic. Date: Thu, 28 Mar 2013 16:09:30 +0000 Message-ID: <1364486970-14990-5-git-send-email-tim@xen.org> References: <1364486970-14990-1-git-send-email-tim@xen.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1364486970-14990-1-git-send-email-tim@xen.org> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: xen-devel@lists.xen.org Cc: suravee.suthikulpanit@amd.com, JBeulich@suse.com List-Id: xen-devel@lists.xenproject.org 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 --- xen/arch/x86/hvm/rtc.c | 40 ++++++++++++++++++++-------------------- 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/xen/arch/x86/hvm/rtc.c b/xen/arch/x86/hvm/rtc.c index 88cacd1..26ab12c 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); -- 1.7.10.4