From: http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/d545a95fca73 # HG changeset 746+749 patch # User Keir Fraser # Date 1227879027 0 # Node ID d545a95fca739d0b1963b73a9eb64ea64a244e76 # Parent 2268be46c75ec6eddb7cd387af8a236a565f6140 Subject: linux/x86: use shared page indicating the need for an EOI notification Patch-mainline: obsolete Signed-off-by: Jan Beulich From: http://xenbits.xensource.com/linux-2.6.18-xen.hg?rev/cdc6729dc702 Subject: evtchn: Fix the build. Signed-off-by: Keir Fraser Index: head-2008-12-01/drivers/xen/core/evtchn.c =================================================================== --- head-2008-12-01.orig/drivers/xen/core/evtchn.c 2008-12-01 11:22:35.000000000 +0100 +++ head-2008-12-01/drivers/xen/core/evtchn.c 2008-12-01 11:23:06.000000000 +0100 @@ -123,9 +123,6 @@ DEFINE_PER_CPU(int, ipi_to_irq[NR_IPIS]) /* Reference counts for bindings to IRQs. */ static int irq_bindcount[NR_IRQS]; -/* Bitmap indicating which PIRQs require Xen to be notified on unmask. */ -static DECLARE_BITMAP(pirq_needs_eoi, NR_PIRQS); - #ifdef CONFIG_SMP static u8 cpu_evtchn[NR_EVENT_CHANNELS]; @@ -756,16 +753,48 @@ static struct hw_interrupt_type dynirq_t .retrigger = resend_irq_on_evtchn, }; -static inline void pirq_unmask_notify(int irq) +/* Bitmap indicating which PIRQs require Xen to be notified on unmask. */ +static int pirq_eoi_does_unmask; +static DECLARE_BITMAP(pirq_needs_eoi, ALIGN(NR_PIRQS, PAGE_SIZE * 8)) + __attribute__ ((__section__(".bss.page_aligned"), __aligned__(PAGE_SIZE))); + +static void pirq_unmask_and_notify(unsigned int evtchn, unsigned int irq) { struct physdev_eoi eoi = { .irq = evtchn_get_xen_pirq(irq) }; - if (unlikely(test_bit(irq - PIRQ_BASE, pirq_needs_eoi))) - VOID(HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi)); + + if (pirq_eoi_does_unmask) { + if (test_bit(eoi.irq, pirq_needs_eoi)) + VOID(HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi)); + else + unmask_evtchn(evtchn); + } else if (test_bit(irq - PIRQ_BASE, pirq_needs_eoi)) { + if (smp_processor_id() != cpu_from_evtchn(evtchn)) { + struct evtchn_unmask unmask = { .port = evtchn }; + struct multicall_entry mcl[2]; + + mcl[0].op = __HYPERVISOR_event_channel_op; + mcl[0].args[0] = EVTCHNOP_unmask; + mcl[0].args[1] = (unsigned long)&unmask; + mcl[1].op = __HYPERVISOR_physdev_op; + mcl[1].args[0] = PHYSDEVOP_eoi; + mcl[1].args[1] = (unsigned long)&eoi; + + if (HYPERVISOR_multicall(mcl, 2)) + BUG(); + } else { + unmask_evtchn(evtchn); + VOID(HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi)); + } + } else + unmask_evtchn(evtchn); } static inline void pirq_query_unmask(int irq) { struct physdev_irq_status_query irq_status; + + if (pirq_eoi_does_unmask) + return; irq_status.irq = evtchn_get_xen_pirq(irq); if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status)) irq_status.flags = 0; @@ -806,8 +835,7 @@ static unsigned int startup_pirq(unsigne irq_info[irq] = mk_irq_info(IRQT_PIRQ, bind_pirq.pirq, evtchn); out: - unmask_evtchn(evtchn); - pirq_unmask_notify(irq); + pirq_unmask_and_notify(evtchn, irq); return 0; } @@ -859,10 +887,8 @@ static void end_pirq(unsigned int irq) if ((irq_desc[irq].status & (IRQ_DISABLED|IRQ_PENDING)) == (IRQ_DISABLED|IRQ_PENDING)) { shutdown_pirq(irq); - } else if (VALID_EVTCHN(evtchn)) { - unmask_evtchn(evtchn); - pirq_unmask_notify(irq); - } + } else if (VALID_EVTCHN(evtchn)) + pirq_unmask_and_notify(evtchn, irq); } static struct hw_interrupt_type pirq_type = { @@ -1012,6 +1038,14 @@ void irq_resume(void) init_evtchn_cpu_bindings(); + if (pirq_eoi_does_unmask) { + struct physdev_pirq_eoi_mfn eoi_mfn; + + eoi_mfn.mfn = virt_to_bus(pirq_needs_eoi) >> PAGE_SHIFT; + if (HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_mfn, &eoi_mfn)) + BUG(); + } + /* New event-channel space is not 'live' yet. */ for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++) mask_evtchn(evtchn); @@ -1098,9 +1132,15 @@ int evtchn_get_xen_pirq(int irq) void __init xen_init_IRQ(void) { unsigned int i; + struct physdev_pirq_eoi_mfn eoi_mfn; init_evtchn_cpu_bindings(); + BUG_ON(!bitmap_empty(pirq_needs_eoi, PAGE_SIZE * 8)); + eoi_mfn.mfn = virt_to_bus(pirq_needs_eoi) >> PAGE_SHIFT; + if (HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_mfn, &eoi_mfn) == 0) + pirq_eoi_does_unmask = 1; + /* No event channels are 'live' right now. */ for (i = 0; i < NR_EVENT_CHANNELS; i++) mask_evtchn(i); Index: head-2008-12-01/include/xen/interface/physdev.h =================================================================== --- head-2008-12-01.orig/include/xen/interface/physdev.h 2008-12-01 11:22:59.000000000 +0100 +++ head-2008-12-01/include/xen/interface/physdev.h 2008-12-01 11:23:06.000000000 +0100 @@ -41,6 +41,21 @@ typedef struct physdev_eoi physdev_eoi_t DEFINE_XEN_GUEST_HANDLE(physdev_eoi_t); /* + * Register a shared page for the hypervisor to indicate whether the guest + * must issue PHYSDEVOP_eoi. The semantics of PHYSDEVOP_eoi change slightly + * once the guest used this function in that the associated event channel + * will automatically get unmasked. The page registered is used as a bit + * array indexed by Xen's PIRQ value. + */ +#define PHYSDEVOP_pirq_eoi_mfn 17 +struct physdev_pirq_eoi_mfn { + /* IN */ + xen_pfn_t mfn; +}; +typedef struct physdev_pirq_eoi_mfn physdev_pirq_eoi_mfn_t; +DEFINE_XEN_GUEST_HANDLE(physdev_pirq_eoi_mfn_t); + +/* * Query the status of an IRQ line. * @arg == pointer to physdev_irq_status_query structure. */