xen: move events.c to drivers/xen for IA64/Xen support
authorIsaku Yamahata <yamahata@valinux.co.jp>
Wed, 2 Apr 2008 17:53:55 +0000 (10:53 -0700)
committerIngo Molnar <mingo@elte.hu>
Thu, 24 Apr 2008 21:57:32 +0000 (23:57 +0200)
move arch/x86/xen/events.c undedr drivers/xen to share codes
with x86 and ia64. And minor adjustment to compile.
ia64/xen also uses events.c

Signed-off-by: Yaozu (Eddie) Dong <eddie.dong@intel.com>
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/xen/Makefile
arch/x86/xen/events.c [deleted file]
arch/x86/xen/xen-ops.h
drivers/xen/Makefile
drivers/xen/events.c [new file with mode: 0644]
include/xen/xen-ops.h [new file with mode: 0644]

index c5e9aa4..95c5926 100644 (file)
@@ -1,4 +1,4 @@
 obj-y          := enlighten.o setup.o multicalls.o mmu.o \
-                       events.o time.o manage.o xen-asm.o
+                       time.o manage.o xen-asm.o
 
 obj-$(CONFIG_SMP)      += smp.o
diff --git a/arch/x86/xen/events.c b/arch/x86/xen/events.c
deleted file mode 100644 (file)
index 85bac29..0000000
+++ /dev/null
@@ -1,658 +0,0 @@
-/*
- * Xen event channels
- *
- * Xen models interrupts with abstract event channels.  Because each
- * domain gets 1024 event channels, but NR_IRQ is not that large, we
- * must dynamically map irqs<->event channels.  The event channels
- * interface with the rest of the kernel by defining a xen interrupt
- * chip.  When an event is recieved, it is mapped to an irq and sent
- * through the normal interrupt processing path.
- *
- * There are four kinds of events which can be mapped to an event
- * channel:
- *
- * 1. Inter-domain notifications.  This includes all the virtual
- *    device events, since they're driven by front-ends in another domain
- *    (typically dom0).
- * 2. VIRQs, typically used for timers.  These are per-cpu events.
- * 3. IPIs.
- * 4. Hardware interrupts. Not supported at present.
- *
- * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
- */
-
-#include <linux/linkage.h>
-#include <linux/interrupt.h>
-#include <linux/irq.h>
-#include <linux/module.h>
-#include <linux/string.h>
-
-#include <asm/ptrace.h>
-#include <asm/irq.h>
-#include <asm/sync_bitops.h>
-#include <asm/xen/hypercall.h>
-#include <asm/xen/hypervisor.h>
-
-#include <xen/events.h>
-#include <xen/interface/xen.h>
-#include <xen/interface/event_channel.h>
-
-#include "xen-ops.h"
-
-/*
- * This lock protects updates to the following mapping and reference-count
- * arrays. The lock does not need to be acquired to read the mapping tables.
- */
-static DEFINE_SPINLOCK(irq_mapping_update_lock);
-
-/* IRQ <-> VIRQ mapping. */
-static DEFINE_PER_CPU(int, virq_to_irq[NR_VIRQS]) = {[0 ... NR_VIRQS-1] = -1};
-
-/* IRQ <-> IPI mapping */
-static DEFINE_PER_CPU(int, ipi_to_irq[XEN_NR_IPIS]) = {[0 ... XEN_NR_IPIS-1] = -1};
-
-/* Packed IRQ information: binding type, sub-type index, and event channel. */
-struct packed_irq
-{
-       unsigned short evtchn;
-       unsigned char index;
-       unsigned char type;
-};
-
-static struct packed_irq irq_info[NR_IRQS];
-
-/* Binding types. */
-enum {
-       IRQT_UNBOUND,
-       IRQT_PIRQ,
-       IRQT_VIRQ,
-       IRQT_IPI,
-       IRQT_EVTCHN
-};
-
-/* Convenient shorthand for packed representation of an unbound IRQ. */
-#define IRQ_UNBOUND    mk_irq_info(IRQT_UNBOUND, 0, 0)
-
-static int evtchn_to_irq[NR_EVENT_CHANNELS] = {
-       [0 ... NR_EVENT_CHANNELS-1] = -1
-};
-static unsigned long cpu_evtchn_mask[NR_CPUS][NR_EVENT_CHANNELS/BITS_PER_LONG];
-static u8 cpu_evtchn[NR_EVENT_CHANNELS];
-
-/* Reference counts for bindings to IRQs. */
-static int irq_bindcount[NR_IRQS];
-
-/* Xen will never allocate port zero for any purpose. */
-#define VALID_EVTCHN(chn)      ((chn) != 0)
-
-/*
- * Force a proper event-channel callback from Xen after clearing the
- * callback mask. We do this in a very simple manner, by making a call
- * down into Xen. The pending flag will be checked by Xen on return.
- */
-void force_evtchn_callback(void)
-{
-       (void)HYPERVISOR_xen_version(0, NULL);
-}
-EXPORT_SYMBOL_GPL(force_evtchn_callback);
-
-static struct irq_chip xen_dynamic_chip;
-
-/* Constructor for packed IRQ information. */
-static inline struct packed_irq mk_irq_info(u32 type, u32 index, u32 evtchn)
-{
-       return (struct packed_irq) { evtchn, index, type };
-}
-
-/*
- * Accessors for packed IRQ information.
- */
-static inline unsigned int evtchn_from_irq(int irq)
-{
-       return irq_info[irq].evtchn;
-}
-
-static inline unsigned int index_from_irq(int irq)
-{
-       return irq_info[irq].index;
-}
-
-static inline unsigned int type_from_irq(int irq)
-{
-       return irq_info[irq].type;
-}
-
-static inline unsigned long active_evtchns(unsigned int cpu,
-                                          struct shared_info *sh,
-                                          unsigned int idx)
-{
-       return (sh->evtchn_pending[idx] &
-               cpu_evtchn_mask[cpu][idx] &
-               ~sh->evtchn_mask[idx]);
-}
-
-static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
-{
-       int irq = evtchn_to_irq[chn];
-
-       BUG_ON(irq == -1);
-#ifdef CONFIG_SMP
-       irq_desc[irq].affinity = cpumask_of_cpu(cpu);
-#endif
-
-       __clear_bit(chn, cpu_evtchn_mask[cpu_evtchn[chn]]);
-       __set_bit(chn, cpu_evtchn_mask[cpu]);
-
-       cpu_evtchn[chn] = cpu;
-}
-
-static void init_evtchn_cpu_bindings(void)
-{
-#ifdef CONFIG_SMP
-       int i;
-       /* By default all event channels notify CPU#0. */
-       for (i = 0; i < NR_IRQS; i++)
-               irq_desc[i].affinity = cpumask_of_cpu(0);
-#endif
-
-       memset(cpu_evtchn, 0, sizeof(cpu_evtchn));
-       memset(cpu_evtchn_mask[0], ~0, sizeof(cpu_evtchn_mask[0]));
-}
-
-static inline unsigned int cpu_from_evtchn(unsigned int evtchn)
-{
-       return cpu_evtchn[evtchn];
-}
-
-static inline void clear_evtchn(int port)
-{
-       struct shared_info *s = HYPERVISOR_shared_info;
-       sync_clear_bit(port, &s->evtchn_pending[0]);
-}
-
-static inline void set_evtchn(int port)
-{
-       struct shared_info *s = HYPERVISOR_shared_info;
-       sync_set_bit(port, &s->evtchn_pending[0]);
-}
-
-
-/**
- * notify_remote_via_irq - send event to remote end of event channel via irq
- * @irq: irq of event channel to send event to
- *
- * Unlike notify_remote_via_evtchn(), this is safe to use across
- * save/restore. Notifications on a broken connection are silently
- * dropped.
- */
-void notify_remote_via_irq(int irq)
-{
-       int evtchn = evtchn_from_irq(irq);
-
-       if (VALID_EVTCHN(evtchn))
-               notify_remote_via_evtchn(evtchn);
-}
-EXPORT_SYMBOL_GPL(notify_remote_via_irq);
-
-static void mask_evtchn(int port)
-{
-       struct shared_info *s = HYPERVISOR_shared_info;
-       sync_set_bit(port, &s->evtchn_mask[0]);
-}
-
-static void unmask_evtchn(int port)
-{
-       struct shared_info *s = HYPERVISOR_shared_info;
-       unsigned int cpu = get_cpu();
-
-       BUG_ON(!irqs_disabled());
-
-       /* Slow path (hypercall) if this is a non-local port. */
-       if (unlikely(cpu != cpu_from_evtchn(port))) {
-               struct evtchn_unmask unmask = { .port = port };
-               (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
-       } else {
-               struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
-
-               sync_clear_bit(port, &s->evtchn_mask[0]);
-
-               /*
-                * The following is basically the equivalent of
-                * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
-                * the interrupt edge' if the channel is masked.
-                */
-               if (sync_test_bit(port, &s->evtchn_pending[0]) &&
-                   !sync_test_and_set_bit(port / BITS_PER_LONG,
-                                          &vcpu_info->evtchn_pending_sel))
-                       vcpu_info->evtchn_upcall_pending = 1;
-       }
-
-       put_cpu();
-}
-
-static int find_unbound_irq(void)
-{
-       int irq;
-
-       /* Only allocate from dynirq range */
-       for (irq = 0; irq < NR_IRQS; irq++)
-               if (irq_bindcount[irq] == 0)
-                       break;
-
-       if (irq == NR_IRQS)
-               panic("No available IRQ to bind to: increase NR_IRQS!\n");
-
-       return irq;
-}
-
-int bind_evtchn_to_irq(unsigned int evtchn)
-{
-       int irq;
-
-       spin_lock(&irq_mapping_update_lock);
-
-       irq = evtchn_to_irq[evtchn];
-
-       if (irq == -1) {
-               irq = find_unbound_irq();
-
-               dynamic_irq_init(irq);
-               set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
-                                             handle_level_irq, "event");
-
-               evtchn_to_irq[evtchn] = irq;
-               irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn);
-       }
-
-       irq_bindcount[irq]++;
-
-       spin_unlock(&irq_mapping_update_lock);
-
-       return irq;
-}
-EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
-
-static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
-{
-       struct evtchn_bind_ipi bind_ipi;
-       int evtchn, irq;
-
-       spin_lock(&irq_mapping_update_lock);
-
-       irq = per_cpu(ipi_to_irq, cpu)[ipi];
-       if (irq == -1) {
-               irq = find_unbound_irq();
-               if (irq < 0)
-                       goto out;
-
-               dynamic_irq_init(irq);
-               set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
-                                             handle_level_irq, "ipi");
-
-               bind_ipi.vcpu = cpu;
-               if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
-                                               &bind_ipi) != 0)
-                       BUG();
-               evtchn = bind_ipi.port;
-
-               evtchn_to_irq[evtchn] = irq;
-               irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
-
-               per_cpu(ipi_to_irq, cpu)[ipi] = irq;
-
-               bind_evtchn_to_cpu(evtchn, cpu);
-       }
-
-       irq_bindcount[irq]++;
-
- out:
-       spin_unlock(&irq_mapping_update_lock);
-       return irq;
-}
-
-
-static int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
-{
-       struct evtchn_bind_virq bind_virq;
-       int evtchn, irq;
-
-       spin_lock(&irq_mapping_update_lock);
-
-       irq = per_cpu(virq_to_irq, cpu)[virq];
-
-       if (irq == -1) {
-               bind_virq.virq = virq;
-               bind_virq.vcpu = cpu;
-               if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
-                                               &bind_virq) != 0)
-                       BUG();
-               evtchn = bind_virq.port;
-
-               irq = find_unbound_irq();
-
-               dynamic_irq_init(irq);
-               set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
-                                             handle_level_irq, "virq");
-
-               evtchn_to_irq[evtchn] = irq;
-               irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
-
-               per_cpu(virq_to_irq, cpu)[virq] = irq;
-
-               bind_evtchn_to_cpu(evtchn, cpu);
-       }
-
-       irq_bindcount[irq]++;
-
-       spin_unlock(&irq_mapping_update_lock);
-
-       return irq;
-}
-
-static void unbind_from_irq(unsigned int irq)
-{
-       struct evtchn_close close;
-       int evtchn = evtchn_from_irq(irq);
-
-       spin_lock(&irq_mapping_update_lock);
-
-       if (VALID_EVTCHN(evtchn) && (--irq_bindcount[irq] == 0)) {
-               close.port = evtchn;
-               if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
-                       BUG();
-
-               switch (type_from_irq(irq)) {
-               case IRQT_VIRQ:
-                       per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
-                               [index_from_irq(irq)] = -1;
-                       break;
-               default:
-                       break;
-               }
-
-               /* Closed ports are implicitly re-bound to VCPU0. */
-               bind_evtchn_to_cpu(evtchn, 0);
-
-               evtchn_to_irq[evtchn] = -1;
-               irq_info[irq] = IRQ_UNBOUND;
-
-               dynamic_irq_init(irq);
-       }
-
-       spin_unlock(&irq_mapping_update_lock);
-}
-
-int bind_evtchn_to_irqhandler(unsigned int evtchn,
-                             irq_handler_t handler,
-                             unsigned long irqflags,
-                             const char *devname, void *dev_id)
-{
-       unsigned int irq;
-       int retval;
-
-       irq = bind_evtchn_to_irq(evtchn);
-       retval = request_irq(irq, handler, irqflags, devname, dev_id);
-       if (retval != 0) {
-               unbind_from_irq(irq);
-               return retval;
-       }
-
-       return irq;
-}
-EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
-
-int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
-                           irq_handler_t handler,
-                           unsigned long irqflags, const char *devname, void *dev_id)
-{
-       unsigned int irq;
-       int retval;
-
-       irq = bind_virq_to_irq(virq, cpu);
-       retval = request_irq(irq, handler, irqflags, devname, dev_id);
-       if (retval != 0) {
-               unbind_from_irq(irq);
-               return retval;
-       }
-
-       return irq;
-}
-EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
-
-int bind_ipi_to_irqhandler(enum ipi_vector ipi,
-                          unsigned int cpu,
-                          irq_handler_t handler,
-                          unsigned long irqflags,
-                          const char *devname,
-                          void *dev_id)
-{
-       int irq, retval;
-
-       irq = bind_ipi_to_irq(ipi, cpu);
-       if (irq < 0)
-               return irq;
-
-       retval = request_irq(irq, handler, irqflags, devname, dev_id);
-       if (retval != 0) {
-               unbind_from_irq(irq);
-               return retval;
-       }
-
-       return irq;
-}
-
-void unbind_from_irqhandler(unsigned int irq, void *dev_id)
-{
-       free_irq(irq, dev_id);
-       unbind_from_irq(irq);
-}
-EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
-
-void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
-{
-       int irq = per_cpu(ipi_to_irq, cpu)[vector];
-       BUG_ON(irq < 0);
-       notify_remote_via_irq(irq);
-}
-
-irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
-{
-       struct shared_info *sh = HYPERVISOR_shared_info;
-       int cpu = smp_processor_id();
-       int i;
-       unsigned long flags;
-       static DEFINE_SPINLOCK(debug_lock);
-
-       spin_lock_irqsave(&debug_lock, flags);
-
-       printk("vcpu %d\n  ", cpu);
-
-       for_each_online_cpu(i) {
-               struct vcpu_info *v = per_cpu(xen_vcpu, i);
-               printk("%d: masked=%d pending=%d event_sel %08lx\n  ", i,
-                       (get_irq_regs() && i == cpu) ? !(get_irq_regs()->flags & X86_EFLAGS_IF) : v->evtchn_upcall_mask,
-                       v->evtchn_upcall_pending,
-                       v->evtchn_pending_sel);
-       }
-       printk("pending:\n   ");
-       for(i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
-               printk("%08lx%s", sh->evtchn_pending[i],
-                       i % 8 == 0 ? "\n   " : " ");
-       printk("\nmasks:\n   ");
-       for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
-               printk("%08lx%s", sh->evtchn_mask[i],
-                       i % 8 == 0 ? "\n   " : " ");
-
-       printk("\nunmasked:\n   ");
-       for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
-               printk("%08lx%s", sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
-                       i % 8 == 0 ? "\n   " : " ");
-
-       printk("\npending list:\n");
-       for(i = 0; i < NR_EVENT_CHANNELS; i++) {
-               if (sync_test_bit(i, sh->evtchn_pending)) {
-                       printk("  %d: event %d -> irq %d\n",
-                               cpu_evtchn[i], i,
-                               evtchn_to_irq[i]);
-               }
-       }
-
-       spin_unlock_irqrestore(&debug_lock, flags);
-
-       return IRQ_HANDLED;
-}
-
-
-/*
- * Search the CPUs pending events bitmasks.  For each one found, map
- * the event number to an irq, and feed it into do_IRQ() for
- * handling.
- *
- * Xen uses a two-level bitmap to speed searching.  The first level is
- * a bitset of words which contain pending event bits.  The second
- * level is a bitset of pending events themselves.
- */
-void xen_evtchn_do_upcall(struct pt_regs *regs)
-{
-       int cpu = get_cpu();
-       struct shared_info *s = HYPERVISOR_shared_info;
-       struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
-       static DEFINE_PER_CPU(unsigned, nesting_count);
-       unsigned count;
-
-       do {
-               unsigned long pending_words;
-
-               vcpu_info->evtchn_upcall_pending = 0;
-
-               if (__get_cpu_var(nesting_count)++)
-                       goto out;
-
-               /* NB. No need for a barrier here -- XCHG is a barrier on x86. */
-               pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
-               while (pending_words != 0) {
-                       unsigned long pending_bits;
-                       int word_idx = __ffs(pending_words);
-                       pending_words &= ~(1UL << word_idx);
-
-                       while ((pending_bits = active_evtchns(cpu, s, word_idx)) != 0) {
-                               int bit_idx = __ffs(pending_bits);
-                               int port = (word_idx * BITS_PER_LONG) + bit_idx;
-                               int irq = evtchn_to_irq[port];
-
-                               if (irq != -1) {
-                                       regs->orig_ax = ~irq;
-                                       do_IRQ(regs);
-                               }
-                       }
-               }
-
-               BUG_ON(!irqs_disabled());
-
-               count = __get_cpu_var(nesting_count);
-               __get_cpu_var(nesting_count) = 0;
-       } while(count != 1);
-
-out:
-       put_cpu();
-}
-
-/* Rebind an evtchn so that it gets delivered to a specific cpu */
-static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
-{
-       struct evtchn_bind_vcpu bind_vcpu;
-       int evtchn = evtchn_from_irq(irq);
-
-       if (!VALID_EVTCHN(evtchn))
-               return;
-
-       /* Send future instances of this interrupt to other vcpu. */
-       bind_vcpu.port = evtchn;
-       bind_vcpu.vcpu = tcpu;
-
-       /*
-        * If this fails, it usually just indicates that we're dealing with a
-        * virq or IPI channel, which don't actually need to be rebound. Ignore
-        * it, but don't do the xenlinux-level rebind in that case.
-        */
-       if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
-               bind_evtchn_to_cpu(evtchn, tcpu);
-}
-
-
-static void set_affinity_irq(unsigned irq, cpumask_t dest)
-{
-       unsigned tcpu = first_cpu(dest);
-       rebind_irq_to_cpu(irq, tcpu);
-}
-
-static void enable_dynirq(unsigned int irq)
-{
-       int evtchn = evtchn_from_irq(irq);
-
-       if (VALID_EVTCHN(evtchn))
-               unmask_evtchn(evtchn);
-}
-
-static void disable_dynirq(unsigned int irq)
-{
-       int evtchn = evtchn_from_irq(irq);
-
-       if (VALID_EVTCHN(evtchn))
-               mask_evtchn(evtchn);
-}
-
-static void ack_dynirq(unsigned int irq)
-{
-       int evtchn = evtchn_from_irq(irq);
-
-       move_native_irq(irq);
-
-       if (VALID_EVTCHN(evtchn))
-               clear_evtchn(evtchn);
-}
-
-static int retrigger_dynirq(unsigned int irq)
-{
-       int evtchn = evtchn_from_irq(irq);
-       struct shared_info *sh = HYPERVISOR_shared_info;
-       int ret = 0;
-
-       if (VALID_EVTCHN(evtchn)) {
-               int masked;
-
-               masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
-               sync_set_bit(evtchn, sh->evtchn_pending);
-               if (!masked)
-                       unmask_evtchn(evtchn);
-               ret = 1;
-       }
-
-       return ret;
-}
-
-static struct irq_chip xen_dynamic_chip __read_mostly = {
-       .name           = "xen-dyn",
-       .mask           = disable_dynirq,
-       .unmask         = enable_dynirq,
-       .ack            = ack_dynirq,
-       .set_affinity   = set_affinity_irq,
-       .retrigger      = retrigger_dynirq,
-};
-
-void __init xen_init_IRQ(void)
-{
-       int i;
-
-       init_evtchn_cpu_bindings();
-
-       /* No event channels are 'live' right now. */
-       for (i = 0; i < NR_EVENT_CHANNELS; i++)
-               mask_evtchn(i);
-
-       /* Dynamic IRQ space is currently unbound. Zero the refcnts. */
-       for (i = 0; i < NR_IRQS; i++)
-               irq_bindcount[i] = 0;
-
-       irq_ctx_init(smp_processor_id());
-}
index 22395d2..f1063ae 100644 (file)
@@ -3,6 +3,7 @@
 
 #include <linux/init.h>
 #include <linux/irqreturn.h>
+#include <xen/xen-ops.h>
 
 /* These are code, but not functions.  Defined in entry.S */
 extern const char xen_hypervisor_callback[];
@@ -10,7 +11,6 @@ extern const char xen_failsafe_callback[];
 
 void xen_copy_trap_info(struct trap_info *traps);
 
-DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu);
 DECLARE_PER_CPU(unsigned long, xen_cr3);
 DECLARE_PER_CPU(unsigned long, xen_current_cr3);
 
index 609fdda..823ce78 100644 (file)
@@ -1,2 +1,2 @@
-obj-y  += grant-table.o features.o
+obj-y  += grant-table.o features.o events.o
 obj-y  += xenbus/
diff --git a/drivers/xen/events.c b/drivers/xen/events.c
new file mode 100644 (file)
index 0000000..c50d499
--- /dev/null
@@ -0,0 +1,657 @@
+/*
+ * Xen event channels
+ *
+ * Xen models interrupts with abstract event channels.  Because each
+ * domain gets 1024 event channels, but NR_IRQ is not that large, we
+ * must dynamically map irqs<->event channels.  The event channels
+ * interface with the rest of the kernel by defining a xen interrupt
+ * chip.  When an event is recieved, it is mapped to an irq and sent
+ * through the normal interrupt processing path.
+ *
+ * There are four kinds of events which can be mapped to an event
+ * channel:
+ *
+ * 1. Inter-domain notifications.  This includes all the virtual
+ *    device events, since they're driven by front-ends in another domain
+ *    (typically dom0).
+ * 2. VIRQs, typically used for timers.  These are per-cpu events.
+ * 3. IPIs.
+ * 4. Hardware interrupts. Not supported at present.
+ *
+ * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
+ */
+
+#include <linux/linkage.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/string.h>
+
+#include <asm/ptrace.h>
+#include <asm/irq.h>
+#include <asm/sync_bitops.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/hypervisor.h>
+
+#include <xen/xen-ops.h>
+#include <xen/events.h>
+#include <xen/interface/xen.h>
+#include <xen/interface/event_channel.h>
+
+/*
+ * This lock protects updates to the following mapping and reference-count
+ * arrays. The lock does not need to be acquired to read the mapping tables.
+ */
+static DEFINE_SPINLOCK(irq_mapping_update_lock);
+
+/* IRQ <-> VIRQ mapping. */
+static DEFINE_PER_CPU(int, virq_to_irq[NR_VIRQS]) = {[0 ... NR_VIRQS-1] = -1};
+
+/* IRQ <-> IPI mapping */
+static DEFINE_PER_CPU(int, ipi_to_irq[XEN_NR_IPIS]) = {[0 ... XEN_NR_IPIS-1] = -1};
+
+/* Packed IRQ information: binding type, sub-type index, and event channel. */
+struct packed_irq
+{
+       unsigned short evtchn;
+       unsigned char index;
+       unsigned char type;
+};
+
+static struct packed_irq irq_info[NR_IRQS];
+
+/* Binding types. */
+enum {
+       IRQT_UNBOUND,
+       IRQT_PIRQ,
+       IRQT_VIRQ,
+       IRQT_IPI,
+       IRQT_EVTCHN
+};
+
+/* Convenient shorthand for packed representation of an unbound IRQ. */
+#define IRQ_UNBOUND    mk_irq_info(IRQT_UNBOUND, 0, 0)
+
+static int evtchn_to_irq[NR_EVENT_CHANNELS] = {
+       [0 ... NR_EVENT_CHANNELS-1] = -1
+};
+static unsigned long cpu_evtchn_mask[NR_CPUS][NR_EVENT_CHANNELS/BITS_PER_LONG];
+static u8 cpu_evtchn[NR_EVENT_CHANNELS];
+
+/* Reference counts for bindings to IRQs. */
+static int irq_bindcount[NR_IRQS];
+
+/* Xen will never allocate port zero for any purpose. */
+#define VALID_EVTCHN(chn)      ((chn) != 0)
+
+/*
+ * Force a proper event-channel callback from Xen after clearing the
+ * callback mask. We do this in a very simple manner, by making a call
+ * down into Xen. The pending flag will be checked by Xen on return.
+ */
+void force_evtchn_callback(void)
+{
+       (void)HYPERVISOR_xen_version(0, NULL);
+}
+EXPORT_SYMBOL_GPL(force_evtchn_callback);
+
+static struct irq_chip xen_dynamic_chip;
+
+/* Constructor for packed IRQ information. */
+static inline struct packed_irq mk_irq_info(u32 type, u32 index, u32 evtchn)
+{
+       return (struct packed_irq) { evtchn, index, type };
+}
+
+/*
+ * Accessors for packed IRQ information.
+ */
+static inline unsigned int evtchn_from_irq(int irq)
+{
+       return irq_info[irq].evtchn;
+}
+
+static inline unsigned int index_from_irq(int irq)
+{
+       return irq_info[irq].index;
+}
+
+static inline unsigned int type_from_irq(int irq)
+{
+       return irq_info[irq].type;
+}
+
+static inline unsigned long active_evtchns(unsigned int cpu,
+                                          struct shared_info *sh,
+                                          unsigned int idx)
+{
+       return (sh->evtchn_pending[idx] &
+               cpu_evtchn_mask[cpu][idx] &
+               ~sh->evtchn_mask[idx]);
+}
+
+static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
+{
+       int irq = evtchn_to_irq[chn];
+
+       BUG_ON(irq == -1);
+#ifdef CONFIG_SMP
+       irq_desc[irq].affinity = cpumask_of_cpu(cpu);
+#endif
+
+       __clear_bit(chn, cpu_evtchn_mask[cpu_evtchn[chn]]);
+       __set_bit(chn, cpu_evtchn_mask[cpu]);
+
+       cpu_evtchn[chn] = cpu;
+}
+
+static void init_evtchn_cpu_bindings(void)
+{
+#ifdef CONFIG_SMP
+       int i;
+       /* By default all event channels notify CPU#0. */
+       for (i = 0; i < NR_IRQS; i++)
+               irq_desc[i].affinity = cpumask_of_cpu(0);
+#endif
+
+       memset(cpu_evtchn, 0, sizeof(cpu_evtchn));
+       memset(cpu_evtchn_mask[0], ~0, sizeof(cpu_evtchn_mask[0]));
+}
+
+static inline unsigned int cpu_from_evtchn(unsigned int evtchn)
+{
+       return cpu_evtchn[evtchn];
+}
+
+static inline void clear_evtchn(int port)
+{
+       struct shared_info *s = HYPERVISOR_shared_info;
+       sync_clear_bit(port, &s->evtchn_pending[0]);
+}
+
+static inline void set_evtchn(int port)
+{
+       struct shared_info *s = HYPERVISOR_shared_info;
+       sync_set_bit(port, &s->evtchn_pending[0]);
+}
+
+
+/**
+ * notify_remote_via_irq - send event to remote end of event channel via irq
+ * @irq: irq of event channel to send event to
+ *
+ * Unlike notify_remote_via_evtchn(), this is safe to use across
+ * save/restore. Notifications on a broken connection are silently
+ * dropped.
+ */
+void notify_remote_via_irq(int irq)
+{
+       int evtchn = evtchn_from_irq(irq);
+
+       if (VALID_EVTCHN(evtchn))
+               notify_remote_via_evtchn(evtchn);
+}
+EXPORT_SYMBOL_GPL(notify_remote_via_irq);
+
+static void mask_evtchn(int port)
+{
+       struct shared_info *s = HYPERVISOR_shared_info;
+       sync_set_bit(port, &s->evtchn_mask[0]);
+}
+
+static void unmask_evtchn(int port)
+{
+       struct shared_info *s = HYPERVISOR_shared_info;
+       unsigned int cpu = get_cpu();
+
+       BUG_ON(!irqs_disabled());
+
+       /* Slow path (hypercall) if this is a non-local port. */
+       if (unlikely(cpu != cpu_from_evtchn(port))) {
+               struct evtchn_unmask unmask = { .port = port };
+               (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
+       } else {
+               struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
+
+               sync_clear_bit(port, &s->evtchn_mask[0]);
+
+               /*
+                * The following is basically the equivalent of
+                * 'hw_resend_irq'. Just like a real IO-APIC we 'lose
+                * the interrupt edge' if the channel is masked.
+                */
+               if (sync_test_bit(port, &s->evtchn_pending[0]) &&
+                   !sync_test_and_set_bit(port / BITS_PER_LONG,
+                                          &vcpu_info->evtchn_pending_sel))
+                       vcpu_info->evtchn_upcall_pending = 1;
+       }
+
+       put_cpu();
+}
+
+static int find_unbound_irq(void)
+{
+       int irq;
+
+       /* Only allocate from dynirq range */
+       for (irq = 0; irq < NR_IRQS; irq++)
+               if (irq_bindcount[irq] == 0)
+                       break;
+
+       if (irq == NR_IRQS)
+               panic("No available IRQ to bind to: increase NR_IRQS!\n");
+
+       return irq;
+}
+
+int bind_evtchn_to_irq(unsigned int evtchn)
+{
+       int irq;
+
+       spin_lock(&irq_mapping_update_lock);
+
+       irq = evtchn_to_irq[evtchn];
+
+       if (irq == -1) {
+               irq = find_unbound_irq();
+
+               dynamic_irq_init(irq);
+               set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
+                                             handle_level_irq, "event");
+
+               evtchn_to_irq[evtchn] = irq;
+               irq_info[irq] = mk_irq_info(IRQT_EVTCHN, 0, evtchn);
+       }
+
+       irq_bindcount[irq]++;
+
+       spin_unlock(&irq_mapping_update_lock);
+
+       return irq;
+}
+EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
+
+static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
+{
+       struct evtchn_bind_ipi bind_ipi;
+       int evtchn, irq;
+
+       spin_lock(&irq_mapping_update_lock);
+
+       irq = per_cpu(ipi_to_irq, cpu)[ipi];
+       if (irq == -1) {
+               irq = find_unbound_irq();
+               if (irq < 0)
+                       goto out;
+
+               dynamic_irq_init(irq);
+               set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
+                                             handle_level_irq, "ipi");
+
+               bind_ipi.vcpu = cpu;
+               if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
+                                               &bind_ipi) != 0)
+                       BUG();
+               evtchn = bind_ipi.port;
+
+               evtchn_to_irq[evtchn] = irq;
+               irq_info[irq] = mk_irq_info(IRQT_IPI, ipi, evtchn);
+
+               per_cpu(ipi_to_irq, cpu)[ipi] = irq;
+
+               bind_evtchn_to_cpu(evtchn, cpu);
+       }
+
+       irq_bindcount[irq]++;
+
+ out:
+       spin_unlock(&irq_mapping_update_lock);
+       return irq;
+}
+
+
+static int bind_virq_to_irq(unsigned int virq, unsigned int cpu)
+{
+       struct evtchn_bind_virq bind_virq;
+       int evtchn, irq;
+
+       spin_lock(&irq_mapping_update_lock);
+
+       irq = per_cpu(virq_to_irq, cpu)[virq];
+
+       if (irq == -1) {
+               bind_virq.virq = virq;
+               bind_virq.vcpu = cpu;
+               if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
+                                               &bind_virq) != 0)
+                       BUG();
+               evtchn = bind_virq.port;
+
+               irq = find_unbound_irq();
+
+               dynamic_irq_init(irq);
+               set_irq_chip_and_handler_name(irq, &xen_dynamic_chip,
+                                             handle_level_irq, "virq");
+
+               evtchn_to_irq[evtchn] = irq;
+               irq_info[irq] = mk_irq_info(IRQT_VIRQ, virq, evtchn);
+
+               per_cpu(virq_to_irq, cpu)[virq] = irq;
+
+               bind_evtchn_to_cpu(evtchn, cpu);
+       }
+
+       irq_bindcount[irq]++;
+
+       spin_unlock(&irq_mapping_update_lock);
+
+       return irq;
+}
+
+static void unbind_from_irq(unsigned int irq)
+{
+       struct evtchn_close close;
+       int evtchn = evtchn_from_irq(irq);
+
+       spin_lock(&irq_mapping_update_lock);
+
+       if (VALID_EVTCHN(evtchn) && (--irq_bindcount[irq] == 0)) {
+               close.port = evtchn;
+               if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
+                       BUG();
+
+               switch (type_from_irq(irq)) {
+               case IRQT_VIRQ:
+                       per_cpu(virq_to_irq, cpu_from_evtchn(evtchn))
+                               [index_from_irq(irq)] = -1;
+                       break;
+               default:
+                       break;
+               }
+
+               /* Closed ports are implicitly re-bound to VCPU0. */
+               bind_evtchn_to_cpu(evtchn, 0);
+
+               evtchn_to_irq[evtchn] = -1;
+               irq_info[irq] = IRQ_UNBOUND;
+
+               dynamic_irq_init(irq);
+       }
+
+       spin_unlock(&irq_mapping_update_lock);
+}
+
+int bind_evtchn_to_irqhandler(unsigned int evtchn,
+                             irq_handler_t handler,
+                             unsigned long irqflags,
+                             const char *devname, void *dev_id)
+{
+       unsigned int irq;
+       int retval;
+
+       irq = bind_evtchn_to_irq(evtchn);
+       retval = request_irq(irq, handler, irqflags, devname, dev_id);
+       if (retval != 0) {
+               unbind_from_irq(irq);
+               return retval;
+       }
+
+       return irq;
+}
+EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
+
+int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
+                           irq_handler_t handler,
+                           unsigned long irqflags, const char *devname, void *dev_id)
+{
+       unsigned int irq;
+       int retval;
+
+       irq = bind_virq_to_irq(virq, cpu);
+       retval = request_irq(irq, handler, irqflags, devname, dev_id);
+       if (retval != 0) {
+               unbind_from_irq(irq);
+               return retval;
+       }
+
+       return irq;
+}
+EXPORT_SYMBOL_GPL(bind_virq_to_irqhandler);
+
+int bind_ipi_to_irqhandler(enum ipi_vector ipi,
+                          unsigned int cpu,
+                          irq_handler_t handler,
+                          unsigned long irqflags,
+                          const char *devname,
+                          void *dev_id)
+{
+       int irq, retval;
+
+       irq = bind_ipi_to_irq(ipi, cpu);
+       if (irq < 0)
+               return irq;
+
+       retval = request_irq(irq, handler, irqflags, devname, dev_id);
+       if (retval != 0) {
+               unbind_from_irq(irq);
+               return retval;
+       }
+
+       return irq;
+}
+
+void unbind_from_irqhandler(unsigned int irq, void *dev_id)
+{
+       free_irq(irq, dev_id);
+       unbind_from_irq(irq);
+}
+EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
+
+void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
+{
+       int irq = per_cpu(ipi_to_irq, cpu)[vector];
+       BUG_ON(irq < 0);
+       notify_remote_via_irq(irq);
+}
+
+irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
+{
+       struct shared_info *sh = HYPERVISOR_shared_info;
+       int cpu = smp_processor_id();
+       int i;
+       unsigned long flags;
+       static DEFINE_SPINLOCK(debug_lock);
+
+       spin_lock_irqsave(&debug_lock, flags);
+
+       printk("vcpu %d\n  ", cpu);
+
+       for_each_online_cpu(i) {
+               struct vcpu_info *v = per_cpu(xen_vcpu, i);
+               printk("%d: masked=%d pending=%d event_sel %08lx\n  ", i,
+                       (get_irq_regs() && i == cpu) ? !(get_irq_regs()->flags & X86_EFLAGS_IF) : v->evtchn_upcall_mask,
+                       v->evtchn_upcall_pending,
+                       v->evtchn_pending_sel);
+       }
+       printk("pending:\n   ");
+       for(i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
+               printk("%08lx%s", sh->evtchn_pending[i],
+                       i % 8 == 0 ? "\n   " : " ");
+       printk("\nmasks:\n   ");
+       for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
+               printk("%08lx%s", sh->evtchn_mask[i],
+                       i % 8 == 0 ? "\n   " : " ");
+
+       printk("\nunmasked:\n   ");
+       for(i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
+               printk("%08lx%s", sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
+                       i % 8 == 0 ? "\n   " : " ");
+
+       printk("\npending list:\n");
+       for(i = 0; i < NR_EVENT_CHANNELS; i++) {
+               if (sync_test_bit(i, sh->evtchn_pending)) {
+                       printk("  %d: event %d -> irq %d\n",
+                               cpu_evtchn[i], i,
+                               evtchn_to_irq[i]);
+               }
+       }
+
+       spin_unlock_irqrestore(&debug_lock, flags);
+
+       return IRQ_HANDLED;
+}
+
+
+/*
+ * Search the CPUs pending events bitmasks.  For each one found, map
+ * the event number to an irq, and feed it into do_IRQ() for
+ * handling.
+ *
+ * Xen uses a two-level bitmap to speed searching.  The first level is
+ * a bitset of words which contain pending event bits.  The second
+ * level is a bitset of pending events themselves.
+ */
+void xen_evtchn_do_upcall(struct pt_regs *regs)
+{
+       int cpu = get_cpu();
+       struct shared_info *s = HYPERVISOR_shared_info;
+       struct vcpu_info *vcpu_info = __get_cpu_var(xen_vcpu);
+       static DEFINE_PER_CPU(unsigned, nesting_count);
+       unsigned count;
+
+       do {
+               unsigned long pending_words;
+
+               vcpu_info->evtchn_upcall_pending = 0;
+
+               if (__get_cpu_var(nesting_count)++)
+                       goto out;
+
+               /* NB. No need for a barrier here -- XCHG is a barrier on x86. */
+               pending_words = xchg(&vcpu_info->evtchn_pending_sel, 0);
+               while (pending_words != 0) {
+                       unsigned long pending_bits;
+                       int word_idx = __ffs(pending_words);
+                       pending_words &= ~(1UL << word_idx);
+
+                       while ((pending_bits = active_evtchns(cpu, s, word_idx)) != 0) {
+                               int bit_idx = __ffs(pending_bits);
+                               int port = (word_idx * BITS_PER_LONG) + bit_idx;
+                               int irq = evtchn_to_irq[port];
+
+                               if (irq != -1) {
+                                       regs->orig_ax = ~irq;
+                                       do_IRQ(regs);
+                               }
+                       }
+               }
+
+               BUG_ON(!irqs_disabled());
+
+               count = __get_cpu_var(nesting_count);
+               __get_cpu_var(nesting_count) = 0;
+       } while(count != 1);
+
+out:
+       put_cpu();
+}
+
+/* Rebind an evtchn so that it gets delivered to a specific cpu */
+static void rebind_irq_to_cpu(unsigned irq, unsigned tcpu)
+{
+       struct evtchn_bind_vcpu bind_vcpu;
+       int evtchn = evtchn_from_irq(irq);
+
+       if (!VALID_EVTCHN(evtchn))
+               return;
+
+       /* Send future instances of this interrupt to other vcpu. */
+       bind_vcpu.port = evtchn;
+       bind_vcpu.vcpu = tcpu;
+
+       /*
+        * If this fails, it usually just indicates that we're dealing with a
+        * virq or IPI channel, which don't actually need to be rebound. Ignore
+        * it, but don't do the xenlinux-level rebind in that case.
+        */
+       if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_vcpu, &bind_vcpu) >= 0)
+               bind_evtchn_to_cpu(evtchn, tcpu);
+}
+
+
+static void set_affinity_irq(unsigned irq, cpumask_t dest)
+{
+       unsigned tcpu = first_cpu(dest);
+       rebind_irq_to_cpu(irq, tcpu);
+}
+
+static void enable_dynirq(unsigned int irq)
+{
+       int evtchn = evtchn_from_irq(irq);
+
+       if (VALID_EVTCHN(evtchn))
+               unmask_evtchn(evtchn);
+}
+
+static void disable_dynirq(unsigned int irq)
+{
+       int evtchn = evtchn_from_irq(irq);
+
+       if (VALID_EVTCHN(evtchn))
+               mask_evtchn(evtchn);
+}
+
+static void ack_dynirq(unsigned int irq)
+{
+       int evtchn = evtchn_from_irq(irq);
+
+       move_native_irq(irq);
+
+       if (VALID_EVTCHN(evtchn))
+               clear_evtchn(evtchn);
+}
+
+static int retrigger_dynirq(unsigned int irq)
+{
+       int evtchn = evtchn_from_irq(irq);
+       struct shared_info *sh = HYPERVISOR_shared_info;
+       int ret = 0;
+
+       if (VALID_EVTCHN(evtchn)) {
+               int masked;
+
+               masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
+               sync_set_bit(evtchn, sh->evtchn_pending);
+               if (!masked)
+                       unmask_evtchn(evtchn);
+               ret = 1;
+       }
+
+       return ret;
+}
+
+static struct irq_chip xen_dynamic_chip __read_mostly = {
+       .name           = "xen-dyn",
+       .mask           = disable_dynirq,
+       .unmask         = enable_dynirq,
+       .ack            = ack_dynirq,
+       .set_affinity   = set_affinity_irq,
+       .retrigger      = retrigger_dynirq,
+};
+
+void __init xen_init_IRQ(void)
+{
+       int i;
+
+       init_evtchn_cpu_bindings();
+
+       /* No event channels are 'live' right now. */
+       for (i = 0; i < NR_EVENT_CHANNELS; i++)
+               mask_evtchn(i);
+
+       /* Dynamic IRQ space is currently unbound. Zero the refcnts. */
+       for (i = 0; i < NR_IRQS; i++)
+               irq_bindcount[i] = 0;
+
+       irq_ctx_init(smp_processor_id());
+}
diff --git a/include/xen/xen-ops.h b/include/xen/xen-ops.h
new file mode 100644 (file)
index 0000000..10ddfe0
--- /dev/null
@@ -0,0 +1,8 @@
+#ifndef INCLUDE_XEN_OPS_H
+#define INCLUDE_XEN_OPS_H
+
+#include <linux/percpu.h>
+
+DECLARE_PER_CPU(struct vcpu_info *, xen_vcpu);
+
+#endif /* INCLUDE_XEN_OPS_H */