From 9846ff10af12f9e7caac696737db6c990592a74a Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Mon, 30 Jan 2012 16:21:48 +0000 Subject: [PATCH] xen: support pirq_eoi_map The pirq_eoi_map is a bitmap offered by Xen to check which pirqs need to be EOI'd without having to issue an hypercall every time. We use PHYSDEVOP_pirq_eoi_gmfn_v2 to map the bitmap, then if we succeed we use pirq_eoi_map to check whether pirqs need eoi. Changes in v3: - explicitly use PHYSDEVOP_pirq_eoi_gmfn_v2 rather than PHYSDEVOP_pirq_eoi_gmfn; - introduce pirq_check_eoi_map, a function to check if a pirq needs an eoi using the map; -rename pirq_needs_eoi into pirq_needs_eoi_flag; - introduce a function pointer called pirq_needs_eoi that is going to be set to the right implementation depending on the availability of PHYSDEVOP_pirq_eoi_gmfn_v2. Signed-off-by: Stefano Stabellini Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/events.c | 26 +++++++++++++++++++++++--- include/xen/interface/physdev.h | 21 +++++++++++++++++++++ 2 files changed, 44 insertions(+), 3 deletions(-) diff --git a/drivers/xen/events.c b/drivers/xen/events.c index e5e5812a1014..4b33acd8ed4e 100644 --- a/drivers/xen/events.c +++ b/drivers/xen/events.c @@ -37,6 +37,7 @@ #include #include #include +#include #include #include #include @@ -109,6 +110,8 @@ struct irq_info { #define PIRQ_SHAREABLE (1 << 1) static int *evtchn_to_irq; +static unsigned long *pirq_eoi_map; +static bool (*pirq_needs_eoi)(unsigned irq); static DEFINE_PER_CPU(unsigned long [NR_EVENT_CHANNELS/BITS_PER_LONG], cpu_evtchn_mask); @@ -269,10 +272,14 @@ static unsigned int cpu_from_evtchn(unsigned int evtchn) return ret; } -static bool pirq_needs_eoi(unsigned irq) +static bool pirq_check_eoi_map(unsigned irq) { - struct irq_info *info = info_for_irq(irq); + return test_bit(irq, pirq_eoi_map); +} +static bool pirq_needs_eoi_flag(unsigned irq) +{ + struct irq_info *info = info_for_irq(irq); BUG_ON(info->type != IRQT_PIRQ); return info->u.pirq.flags & PIRQ_NEEDS_EOI; @@ -1768,7 +1775,7 @@ void xen_callback_vector(void) {} void __init xen_init_IRQ(void) { - int i; + int i, rc; evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq), GFP_KERNEL); @@ -1782,6 +1789,8 @@ void __init xen_init_IRQ(void) for (i = 0; i < NR_EVENT_CHANNELS; i++) mask_evtchn(i); + pirq_needs_eoi = pirq_needs_eoi_flag; + if (xen_hvm_domain()) { xen_callback_vector(); native_init_IRQ(); @@ -1789,8 +1798,19 @@ void __init xen_init_IRQ(void) * __acpi_register_gsi can point at the right function */ pci_xen_hvm_init(); } else { + struct physdev_pirq_eoi_gmfn eoi_gmfn; + irq_ctx_init(smp_processor_id()); if (xen_initial_domain()) pci_xen_initial_domain(); + + pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO); + eoi_gmfn.gmfn = virt_to_mfn(pirq_eoi_map); + rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn); + if (rc != 0) { + free_page((unsigned long) pirq_eoi_map); + pirq_eoi_map = NULL; + } else + pirq_needs_eoi = pirq_check_eoi_map; } } diff --git a/include/xen/interface/physdev.h b/include/xen/interface/physdev.h index 0c28989007fb..9ce788d8cf49 100644 --- a/include/xen/interface/physdev.h +++ b/include/xen/interface/physdev.h @@ -38,6 +38,27 @@ struct physdev_eoi { uint32_t irq; }; +/* + * 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_gmfn_v1 17 +/* + * Register a shared page for the hypervisor to indicate whether the + * guest must issue PHYSDEVOP_eoi. This hypercall is very similar to + * PHYSDEVOP_pirq_eoi_gmfn_v1 but it doesn't change the semantics of + * PHYSDEVOP_eoi. The page registered is used as a bit array indexed by + * Xen's PIRQ value. + */ +#define PHYSDEVOP_pirq_eoi_gmfn_v2 28 +struct physdev_pirq_eoi_gmfn { + /* IN */ + unsigned long gmfn; +}; + /* * Query the status of an IRQ line. * @arg == pointer to physdev_irq_status_query structure. -- 2.39.5