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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH 06/12] xen/events: move 2-level specific code into its own file
From: David Vrabel <david.vrabel@xxxxxxxxxx>
In preparation for alternative event channel ABIs, move all the
functions accessing the shared data structures into their own file.
Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
---
drivers/xen/events/Makefile | 1 +
drivers/xen/events/events.c | 365 +---------------------------------
drivers/xen/events/events_internal.h | 74 +++++++
drivers/xen/events/n-level.c | 315 +++++++++++++++++++++++++++++
4 files changed, 401 insertions(+), 354 deletions(-)
create mode 100644 drivers/xen/events/events_internal.h
create mode 100644 drivers/xen/events/n-level.c
diff --git a/drivers/xen/events/Makefile b/drivers/xen/events/Makefile
index 86fd7c1..aea331e 100644
--- a/drivers/xen/events/Makefile
+++ b/drivers/xen/events/Makefile
@@ -1 +1,2 @@
obj-y += events.o
+obj-y += n-level.o
diff --git a/drivers/xen/events/events.c b/drivers/xen/events/events.c
index 13df85c..8d5a5cf 100644
--- a/drivers/xen/events/events.c
+++ b/drivers/xen/events/events.c
@@ -58,6 +58,8 @@
#include <xen/interface/sched.h>
#include <asm/hw_irq.h>
+#include "events_internal.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.
@@ -72,72 +74,12 @@ static DEFINE_PER_CPU(int [NR_VIRQS], virq_to_irq) = {[0
... NR_VIRQS-1] = -1};
/* IRQ <-> IPI mapping */
static DEFINE_PER_CPU(int [XEN_NR_IPIS], ipi_to_irq) = {[0 ... XEN_NR_IPIS-1]
= -1};
-/* Interrupt types. */
-enum xen_irq_type {
- IRQT_UNBOUND = 0,
- IRQT_PIRQ,
- IRQT_VIRQ,
- IRQT_IPI,
- IRQT_EVTCHN
-};
-
-/*
- * Packed IRQ information:
- * type - enum xen_irq_type
- * event channel - irq->event channel mapping
- * cpu - cpu this event channel is bound to
- * index - type-specific information:
- * PIRQ - physical IRQ, GSI, flags, and owner domain
- * VIRQ - virq number
- * IPI - IPI vector
- * EVTCHN -
- */
-struct irq_info {
- struct list_head list;
- int refcnt;
- enum xen_irq_type type; /* type */
- unsigned irq;
- unsigned short evtchn; /* event channel */
- unsigned short cpu; /* cpu bound */
-
- union {
- unsigned short virq;
- enum ipi_vector ipi;
- struct {
- unsigned short pirq;
- unsigned short gsi;
- unsigned char flags;
- uint16_t domid;
- } pirq;
- } u;
-};
-#define PIRQ_NEEDS_EOI (1 << 0)
-#define PIRQ_SHAREABLE (1 << 1)
-
-static int *evtchn_to_irq;
+int *evtchn_to_irq;
#ifdef CONFIG_X86
static unsigned long *pirq_eoi_map;
#endif
static bool (*pirq_needs_eoi)(unsigned irq);
-/*
- * Note sizeof(xen_ulong_t) can be more than sizeof(unsigned long). Be
- * careful to only use bitops which allow for this (e.g
- * test_bit/find_first_bit and friends but not __ffs) and to pass
- * BITS_PER_EVTCHN_WORD as the bitmask length.
- */
-#define BITS_PER_EVTCHN_WORD (sizeof(xen_ulong_t)*8)
-/*
- * Make a bitmask (i.e. unsigned long *) of a xen_ulong_t
- * array. Primarily to avoid long lines (hence the terse name).
- */
-#define BM(x) (unsigned long *)(x)
-/* Find the first set bit in a evtchn mask */
-#define EVTCHN_FIRST_BIT(w) find_first_bit(BM(&(w)), BITS_PER_EVTCHN_WORD)
-
-static DEFINE_PER_CPU(xen_ulong_t [NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD],
- cpu_evtchn_mask);
-
/* Xen will never allocate port zero for any purpose. */
#define VALID_EVTCHN(chn) ((chn) != 0)
@@ -148,7 +90,7 @@ static void enable_dynirq(struct irq_data *data);
static void disable_dynirq(struct irq_data *data);
/* Get info for IRQ */
-static struct irq_info *info_for_irq(unsigned irq)
+struct irq_info *info_for_irq(unsigned irq)
{
return irq_get_handler_data(irq);
}
@@ -278,12 +220,12 @@ static enum xen_irq_type type_from_irq(unsigned irq)
return info_for_irq(irq)->type;
}
-static unsigned cpu_from_irq(unsigned irq)
+unsigned cpu_from_irq(unsigned irq)
{
return info_for_irq(irq)->cpu;
}
-static unsigned int cpu_from_evtchn(unsigned int evtchn)
+unsigned int cpu_from_evtchn(unsigned int evtchn)
{
int irq = evtchn_to_irq[evtchn];
unsigned ret = 0;
@@ -309,55 +251,21 @@ static bool pirq_needs_eoi_flag(unsigned irq)
return info->u.pirq.flags & PIRQ_NEEDS_EOI;
}
-static inline xen_ulong_t active_evtchns(unsigned int cpu,
- struct shared_info *sh,
- unsigned int idx)
-{
- return sh->evtchn_pending[idx] &
- per_cpu(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];
+ struct irq_info *info = info_for_irq(irq);
BUG_ON(irq == -1);
#ifdef CONFIG_SMP
cpumask_copy(irq_to_desc(irq)->irq_data.affinity, cpumask_of(cpu));
#endif
- clear_bit(chn, BM(per_cpu(cpu_evtchn_mask, cpu_from_irq(irq))));
- set_bit(chn, BM(per_cpu(cpu_evtchn_mask, cpu)));
+ xen_evtchn_port_bind_to_cpu(info, cpu);
- info_for_irq(irq)->cpu = cpu;
-}
-
-static inline void clear_evtchn(int port)
-{
- struct shared_info *s = HYPERVISOR_shared_info;
- sync_clear_bit(port, BM(&s->evtchn_pending[0]));
-}
-
-static inline void set_evtchn(int port)
-{
- struct shared_info *s = HYPERVISOR_shared_info;
- sync_set_bit(port, BM(&s->evtchn_pending[0]));
-}
-
-static inline int test_evtchn(int port)
-{
- struct shared_info *s = HYPERVISOR_shared_info;
- return sync_test_bit(port, BM(&s->evtchn_pending[0]));
-}
-
-static inline int test_and_set_mask(int port)
-{
- struct shared_info *s = HYPERVISOR_shared_info;
- return sync_test_and_set_bit(port, BM(&s->evtchn_mask[0]));
+ info->cpu = cpu;
}
-
/**
* notify_remote_via_irq - send event to remote end of event channel via irq
* @irq: irq of event channel to send event to
@@ -375,63 +283,6 @@ void notify_remote_via_irq(int irq)
}
EXPORT_SYMBOL_GPL(notify_remote_via_irq);
-static void mask_evtchn(int port)
-{
- struct shared_info *s = HYPERVISOR_shared_info;
- sync_set_bit(port, BM(&s->evtchn_mask[0]));
-}
-
-static void unmask_evtchn(int port)
-{
- struct shared_info *s = HYPERVISOR_shared_info;
- unsigned int cpu = get_cpu();
- int do_hypercall = 0, evtchn_pending = 0;
-
- BUG_ON(!irqs_disabled());
-
- if (unlikely((cpu != cpu_from_evtchn(port))))
- do_hypercall = 1;
- else {
- /*
- * Need to clear the mask before checking pending to
- * avoid a race with an event becoming pending.
- *
- * EVTCHNOP_unmask will only trigger an upcall if the
- * mask bit was set, so if a hypercall is needed
- * remask the event.
- */
- sync_clear_bit(port, BM(&s->evtchn_mask[0]));
- evtchn_pending = sync_test_bit(port, BM(&s->evtchn_pending[0]));
-
- if (unlikely(evtchn_pending && xen_hvm_domain())) {
- sync_set_bit(port, BM(&s->evtchn_mask[0]));
- do_hypercall = 1;
- }
- }
-
- /* Slow path (hypercall) if this is a non-local port or if this is
- * an hvm domain and an event is pending (hvm domains don't have
- * their own implementation of irq_enable). */
- if (do_hypercall) {
- struct evtchn_unmask unmask = { .port = port };
- (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
- } else {
- struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
-
- /*
- * 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 (evtchn_pending &&
- !sync_test_and_set_bit(port / BITS_PER_EVTCHN_WORD,
- BM(&vcpu_info->evtchn_pending_sel)))
- vcpu_info->evtchn_upcall_pending = 1;
- }
-
- put_cpu();
-}
-
static void xen_irq_init(unsigned irq)
{
struct irq_info *info;
@@ -1205,215 +1056,21 @@ void xen_send_IPI_one(unsigned int cpu, enum
ipi_vector vector)
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();
- xen_ulong_t *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
- int i;
- unsigned long flags;
- static DEFINE_SPINLOCK(debug_lock);
- struct vcpu_info *v;
-
- spin_lock_irqsave(&debug_lock, flags);
-
- printk("\nvcpu %d\n ", cpu);
-
- for_each_online_cpu(i) {
- int pending;
- v = per_cpu(xen_vcpu, i);
- pending = (get_irq_regs() && i == cpu)
- ? xen_irqs_disabled(get_irq_regs())
- : v->evtchn_upcall_mask;
- printk("%d: masked=%d pending=%d event_sel %0*"PRI_xen_ulong"\n
", i,
- pending, v->evtchn_upcall_pending,
- (int)(sizeof(v->evtchn_pending_sel)*2),
- v->evtchn_pending_sel);
- }
- v = per_cpu(xen_vcpu, cpu);
-
- printk("\npending:\n ");
- for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
- printk("%0*"PRI_xen_ulong"%s",
- (int)sizeof(sh->evtchn_pending[0])*2,
- sh->evtchn_pending[i],
- i % 8 == 0 ? "\n " : " ");
- printk("\nglobal mask:\n ");
- for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
- printk("%0*"PRI_xen_ulong"%s",
- (int)(sizeof(sh->evtchn_mask[0])*2),
- sh->evtchn_mask[i],
- i % 8 == 0 ? "\n " : " ");
-
- printk("\nglobally unmasked:\n ");
- for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
- printk("%0*"PRI_xen_ulong"%s",
- (int)(sizeof(sh->evtchn_mask[0])*2),
- sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
- i % 8 == 0 ? "\n " : " ");
-
- printk("\nlocal cpu%d mask:\n ", cpu);
- for (i = (NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD)-1; i >= 0; i--)
- printk("%0*"PRI_xen_ulong"%s", (int)(sizeof(cpu_evtchn[0])*2),
- cpu_evtchn[i],
- i % 8 == 0 ? "\n " : " ");
-
- printk("\nlocally unmasked:\n ");
- for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
- xen_ulong_t pending = sh->evtchn_pending[i]
- & ~sh->evtchn_mask[i]
- & cpu_evtchn[i];
- printk("%0*"PRI_xen_ulong"%s",
- (int)(sizeof(sh->evtchn_mask[0])*2),
- pending, i % 8 == 0 ? "\n " : " ");
- }
-
- printk("\npending list:\n");
- for (i = 0; i < NR_EVENT_CHANNELS; i++) {
- if (sync_test_bit(i, BM(sh->evtchn_pending))) {
- int word_idx = i / BITS_PER_EVTCHN_WORD;
- printk(" %d: event %d -> irq %d%s%s%s\n",
- cpu_from_evtchn(i), i,
- evtchn_to_irq[i],
- sync_test_bit(word_idx,
BM(&v->evtchn_pending_sel))
- ? "" : " l2-clear",
- !sync_test_bit(i, BM(sh->evtchn_mask))
- ? "" : " globally-masked",
- sync_test_bit(i, BM(cpu_evtchn))
- ? "" : " locally-masked");
- }
- }
-
- spin_unlock_irqrestore(&debug_lock, flags);
-
- return IRQ_HANDLED;
-}
-
static DEFINE_PER_CPU(unsigned, xed_nesting_count);
-static DEFINE_PER_CPU(unsigned int, current_word_idx);
-static DEFINE_PER_CPU(unsigned int, current_bit_idx);
-/*
- * Mask out the i least significant bits of w
- */
-#define MASK_LSBS(w, i) (w & ((~((xen_ulong_t)0UL)) << i))
-
-/*
- * 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.
- */
static void __xen_evtchn_do_upcall(void)
{
- int start_word_idx, start_bit_idx;
- int word_idx, bit_idx;
- int i, irq;
- int cpu = get_cpu();
- struct shared_info *s = HYPERVISOR_shared_info;
struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
+ int cpu = get_cpu();
unsigned count;
do {
- xen_ulong_t pending_words;
- xen_ulong_t pending_bits;
- struct irq_desc *desc;
-
vcpu_info->evtchn_upcall_pending = 0;
if (__this_cpu_inc_return(xed_nesting_count) - 1)
goto out;
- /*
- * Master flag must be cleared /before/ clearing
- * selector flag. xchg_xen_ulong must contain an
- * appropriate barrier.
- */
- if ((irq = per_cpu(virq_to_irq, cpu)[VIRQ_TIMER]) != -1) {
- int evtchn = evtchn_from_irq(irq);
- word_idx = evtchn / BITS_PER_LONG;
- pending_bits = evtchn % BITS_PER_LONG;
- if (active_evtchns(cpu, s, word_idx) & (1ULL <<
pending_bits)) {
- desc = irq_to_desc(irq);
- if (desc)
- generic_handle_irq_desc(irq, desc);
- }
- }
-
- pending_words = xchg_xen_ulong(&vcpu_info->evtchn_pending_sel,
0);
-
- start_word_idx = __this_cpu_read(current_word_idx);
- start_bit_idx = __this_cpu_read(current_bit_idx);
-
- word_idx = start_word_idx;
-
- for (i = 0; pending_words != 0; i++) {
- xen_ulong_t words;
-
- words = MASK_LSBS(pending_words, word_idx);
-
- /*
- * If we masked out all events, wrap to beginning.
- */
- if (words == 0) {
- word_idx = 0;
- bit_idx = 0;
- continue;
- }
- word_idx = EVTCHN_FIRST_BIT(words);
-
- pending_bits = active_evtchns(cpu, s, word_idx);
- bit_idx = 0; /* usually scan entire word from start */
- if (word_idx == start_word_idx) {
- /* We scan the starting word in two parts */
- if (i == 0)
- /* 1st time: start in the middle */
- bit_idx = start_bit_idx;
- else
- /* 2nd time: mask bits done already */
- bit_idx &= (1UL << start_bit_idx) - 1;
- }
-
- do {
- xen_ulong_t bits;
- int port;
-
- bits = MASK_LSBS(pending_bits, bit_idx);
-
- /* If we masked out all events, move on. */
- if (bits == 0)
- break;
-
- bit_idx = EVTCHN_FIRST_BIT(bits);
-
- /* Process port. */
- port = (word_idx * BITS_PER_EVTCHN_WORD) +
bit_idx;
- irq = evtchn_to_irq[port];
-
- if (irq != -1) {
- desc = irq_to_desc(irq);
- if (desc)
- generic_handle_irq_desc(irq,
desc);
- }
-
- bit_idx = (bit_idx + 1) % BITS_PER_EVTCHN_WORD;
-
- /* Next caller starts at last processed + 1 */
- __this_cpu_write(current_word_idx,
- bit_idx ? word_idx :
- (word_idx+1) %
BITS_PER_EVTCHN_WORD);
- __this_cpu_write(current_bit_idx, bit_idx);
- } while (bit_idx != 0);
-
- /* Scan start_l1i twice; all others once. */
- if ((word_idx != start_word_idx) || (i != 0))
- pending_words &= ~(1UL << word_idx);
-
- word_idx = (word_idx + 1) % BITS_PER_EVTCHN_WORD;
- }
+ xen_evtchn_handle_events(cpu);
BUG_ON(!irqs_disabled());
diff --git a/drivers/xen/events/events_internal.h
b/drivers/xen/events/events_internal.h
new file mode 100644
index 0000000..79ac70b
--- /dev/null
+++ b/drivers/xen/events/events_internal.h
@@ -0,0 +1,74 @@
+/*
+ * Xen Event Channels (internal header)
+ *
+ * Copyright (C) 2013 Citrix Systems R&D Ltd.
+ *
+ * This source code is licensed under the GNU General Public License,
+ * Version 2 or later. See the file COPYING for more details.
+ */
+#ifndef __EVENTS_INTERNAL_H__
+#define __EVENTS_INTERNAL_H__
+
+/* Interrupt types. */
+enum xen_irq_type {
+ IRQT_UNBOUND = 0,
+ IRQT_PIRQ,
+ IRQT_VIRQ,
+ IRQT_IPI,
+ IRQT_EVTCHN
+};
+
+/*
+ * Packed IRQ information:
+ * type - enum xen_irq_type
+ * event channel - irq->event channel mapping
+ * cpu - cpu this event channel is bound to
+ * index - type-specific information:
+ * PIRQ - vector, with MSB being "needs EIO", or physical IRQ of the HVM
+ * guest, or GSI (real passthrough IRQ) of the device.
+ * VIRQ - virq number
+ * IPI - IPI vector
+ * EVTCHN -
+ */
+struct irq_info {
+ struct list_head list;
+ int refcnt;
+ enum xen_irq_type type; /* type */
+ unsigned irq;
+ unsigned short evtchn; /* event channel */
+ unsigned short cpu; /* cpu bound */
+
+ union {
+ unsigned short virq;
+ enum ipi_vector ipi;
+ struct {
+ unsigned short pirq;
+ unsigned short gsi;
+ unsigned char vector;
+ unsigned char flags;
+ uint16_t domid;
+ } pirq;
+ } u;
+};
+
+#define PIRQ_NEEDS_EOI (1 << 0)
+#define PIRQ_SHAREABLE (1 << 1)
+
+extern int *evtchn_to_irq;
+
+struct irq_info *info_for_irq(unsigned irq);
+unsigned cpu_from_irq(unsigned irq);
+unsigned cpu_from_evtchn(unsigned int evtchn);
+
+void xen_evtchn_port_bind_to_cpu(struct irq_info *info, int cpu);
+
+void clear_evtchn(int port);
+void set_evtchn(int port);
+int test_evtchn(int port);
+int test_and_set_mask(int port);
+void mask_evtchn(int port);
+void unmask_evtchn(int port);
+
+void xen_evtchn_handle_events(int cpu);
+
+#endif /* #ifndef __EVENTS_INTERNAL_H__ */
diff --git a/drivers/xen/events/n-level.c b/drivers/xen/events/n-level.c
new file mode 100644
index 0000000..05762d5
--- /dev/null
+++ b/drivers/xen/events/n-level.c
@@ -0,0 +1,315 @@
+/*
+ * Xen event channels (N-level ABI)
+ *
+ * Jeremy Fitzhardinge <jeremy@xxxxxxxxxxxxx>, XenSource Inc, 2007
+ */
+
+#include <linux/linkage.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+
+#include <asm/sync_bitops.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/hypervisor.h>
+
+#include <xen/xen.h>
+#include <xen/xen-ops.h>
+#include <xen/events.h>
+#include <xen/interface/xen.h>
+#include <xen/interface/event_channel.h>
+
+#include "events_internal.h"
+
+/*
+ * Note sizeof(xen_ulong_t) can be more than sizeof(unsigned long). Be
+ * careful to only use bitops which allow for this (e.g
+ * test_bit/find_first_bit and friends but not __ffs) and to pass
+ * BITS_PER_EVTCHN_WORD as the bitmask length.
+ */
+#define BITS_PER_EVTCHN_WORD (sizeof(xen_ulong_t)*8)
+/*
+ * Make a bitmask (i.e. unsigned long *) of a xen_ulong_t
+ * array. Primarily to avoid long lines (hence the terse name).
+ */
+#define BM(x) (unsigned long *)(x)
+/* Find the first set bit in a evtchn mask */
+#define EVTCHN_FIRST_BIT(w) find_first_bit(BM(&(w)), BITS_PER_EVTCHN_WORD)
+
+static DEFINE_PER_CPU(xen_ulong_t [NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD],
+ cpu_evtchn_mask);
+
+void xen_evtchn_port_bind_to_cpu(struct irq_info *info, int cpu)
+{
+ clear_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, info->cpu)));
+ set_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, cpu)));
+}
+
+void clear_evtchn(int port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ sync_clear_bit(port, BM(&s->evtchn_pending[0]));
+}
+
+void set_evtchn(int port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ sync_set_bit(port, BM(&s->evtchn_pending[0]));
+}
+
+int test_evtchn(int port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ return sync_test_bit(port, BM(&s->evtchn_pending[0]));
+}
+
+int test_and_set_mask(int port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ return sync_test_and_set_bit(port, BM(&s->evtchn_mask[0]));
+}
+
+void mask_evtchn(int port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ sync_set_bit(port, BM(&s->evtchn_mask[0]));
+}
+
+void unmask_evtchn(int port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ unsigned int cpu = get_cpu();
+ int do_hypercall = 0, evtchn_pending = 0;
+
+ BUG_ON(!irqs_disabled());
+
+ if (unlikely((cpu != cpu_from_evtchn(port))))
+ do_hypercall = 1;
+ else {
+ sync_clear_bit(port, BM(&s->evtchn_mask[0]));
+ evtchn_pending = sync_test_bit(port, BM(&s->evtchn_pending[0]));
+
+ if (unlikely(evtchn_pending && xen_hvm_domain()))
+ do_hypercall = 1;
+ }
+
+ /* Slow path (hypercall) if this is a non-local port or if this is
+ * an hvm domain and an event is pending (hvm domains don't have
+ * their own implementation of irq_enable). */
+ if (do_hypercall) {
+ struct evtchn_unmask unmask = { .port = port };
+ (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
+ } else {
+ struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
+
+ /*
+ * 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 (evtchn_pending &&
+ !sync_test_and_set_bit(port / BITS_PER_EVTCHN_WORD,
+ BM(&vcpu_info->evtchn_pending_sel)))
+ vcpu_info->evtchn_upcall_pending = 1;
+ }
+
+ put_cpu();
+}
+
+static DEFINE_PER_CPU(unsigned int, current_word_idx);
+static DEFINE_PER_CPU(unsigned int, current_bit_idx);
+
+/*
+ * Mask out the i least significant bits of w
+ */
+#define MASK_LSBS(w, i) (w & ((~((xen_ulong_t)0UL)) << i))
+
+static inline xen_ulong_t active_evtchns(unsigned int cpu,
+ struct shared_info *sh,
+ unsigned int idx)
+{
+ return sh->evtchn_pending[idx] &
+ per_cpu(cpu_evtchn_mask, cpu)[idx] &
+ ~sh->evtchn_mask[idx];
+}
+
+/*
+ * Search the CPU's 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_handle_events(int cpu)
+{
+ xen_ulong_t pending_words;
+ int start_word_idx, start_bit_idx;
+ int word_idx, bit_idx;
+ int i;
+ struct shared_info *s = HYPERVISOR_shared_info;
+ struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
+
+ /*
+ * Master flag must be cleared /before/ clearing
+ * selector flag. xchg_xen_ulong must contain an
+ * appropriate barrier.
+ */
+ pending_words = xchg_xen_ulong(&vcpu_info->evtchn_pending_sel, 0);
+
+ start_word_idx = __this_cpu_read(current_word_idx);
+ start_bit_idx = __this_cpu_read(current_bit_idx);
+
+ word_idx = start_word_idx;
+
+ for (i = 0; pending_words != 0; i++) {
+ xen_ulong_t pending_bits;
+ xen_ulong_t words;
+
+ words = MASK_LSBS(pending_words, word_idx);
+
+ /*
+ * If we masked out all events, wrap to beginning.
+ */
+ if (words == 0) {
+ word_idx = 0;
+ bit_idx = 0;
+ continue;
+ }
+ word_idx = EVTCHN_FIRST_BIT(words);
+
+ pending_bits = active_evtchns(cpu, s, word_idx);
+ bit_idx = 0; /* usually scan entire word from start */
+ if (word_idx == start_word_idx) {
+ /* We scan the starting word in two parts */
+ if (i == 0)
+ /* 1st time: start in the middle */
+ bit_idx = start_bit_idx;
+ else
+ /* 2nd time: mask bits done already */
+ bit_idx &= (1UL << start_bit_idx) - 1;
+ }
+
+ do {
+ xen_ulong_t bits;
+ int port, irq;
+ struct irq_desc *desc;
+
+ bits = MASK_LSBS(pending_bits, bit_idx);
+
+ /* If we masked out all events, move on. */
+ if (bits == 0)
+ break;
+
+ bit_idx = EVTCHN_FIRST_BIT(bits);
+
+ /* Process port. */
+ port = (word_idx * BITS_PER_EVTCHN_WORD) + bit_idx;
+ irq = evtchn_to_irq[port];
+
+ if (irq != -1) {
+ desc = irq_to_desc(irq);
+ if (desc)
+ generic_handle_irq_desc(irq, desc);
+ }
+
+ bit_idx = (bit_idx + 1) % BITS_PER_EVTCHN_WORD;
+
+ /* Next caller starts at last processed + 1 */
+ __this_cpu_write(current_word_idx,
+ bit_idx ? word_idx :
+ (word_idx+1) % BITS_PER_EVTCHN_WORD);
+ __this_cpu_write(current_bit_idx, bit_idx);
+ } while (bit_idx != 0);
+
+ /* Scan start_l1i twice; all others once. */
+ if ((word_idx != start_word_idx) || (i != 0))
+ pending_words &= ~(1UL << word_idx);
+
+ word_idx = (word_idx + 1) % BITS_PER_EVTCHN_WORD;
+ }
+}
+
+irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
+{
+ struct shared_info *sh = HYPERVISOR_shared_info;
+ int cpu = smp_processor_id();
+ xen_ulong_t *cpu_evtchn = per_cpu(cpu_evtchn_mask, cpu);
+ int i;
+ unsigned long flags;
+ static DEFINE_SPINLOCK(debug_lock);
+ struct vcpu_info *v;
+
+ spin_lock_irqsave(&debug_lock, flags);
+
+ printk("\nvcpu %d\n ", cpu);
+
+ for_each_online_cpu(i) {
+ int pending;
+ v = per_cpu(xen_vcpu, i);
+ pending = (get_irq_regs() && i == cpu)
+ ? xen_irqs_disabled(get_irq_regs())
+ : v->evtchn_upcall_mask;
+ printk("%d: masked=%d pending=%d event_sel %0*"PRI_xen_ulong"\n
", i,
+ pending, v->evtchn_upcall_pending,
+ (int)(sizeof(v->evtchn_pending_sel)*2),
+ v->evtchn_pending_sel);
+ }
+ v = per_cpu(xen_vcpu, cpu);
+
+ printk("\npending:\n ");
+ for (i = ARRAY_SIZE(sh->evtchn_pending)-1; i >= 0; i--)
+ printk("%0*"PRI_xen_ulong"%s",
+ (int)sizeof(sh->evtchn_pending[0])*2,
+ sh->evtchn_pending[i],
+ i % 8 == 0 ? "\n " : " ");
+ printk("\nglobal mask:\n ");
+ for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
+ printk("%0*"PRI_xen_ulong"%s",
+ (int)(sizeof(sh->evtchn_mask[0])*2),
+ sh->evtchn_mask[i],
+ i % 8 == 0 ? "\n " : " ");
+
+ printk("\nglobally unmasked:\n ");
+ for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--)
+ printk("%0*"PRI_xen_ulong"%s",
+ (int)(sizeof(sh->evtchn_mask[0])*2),
+ sh->evtchn_pending[i] & ~sh->evtchn_mask[i],
+ i % 8 == 0 ? "\n " : " ");
+
+ printk("\nlocal cpu%d mask:\n ", cpu);
+ for (i = (NR_EVENT_CHANNELS/BITS_PER_EVTCHN_WORD)-1; i >= 0; i--)
+ printk("%0*"PRI_xen_ulong"%s", (int)(sizeof(cpu_evtchn[0])*2),
+ cpu_evtchn[i],
+ i % 8 == 0 ? "\n " : " ");
+
+ printk("\nlocally unmasked:\n ");
+ for (i = ARRAY_SIZE(sh->evtchn_mask)-1; i >= 0; i--) {
+ xen_ulong_t pending = sh->evtchn_pending[i]
+ & ~sh->evtchn_mask[i]
+ & cpu_evtchn[i];
+ printk("%0*"PRI_xen_ulong"%s",
+ (int)(sizeof(sh->evtchn_mask[0])*2),
+ pending, i % 8 == 0 ? "\n " : " ");
+ }
+
+ printk("\npending list:\n");
+ for (i = 0; i < NR_EVENT_CHANNELS; i++) {
+ if (sync_test_bit(i, BM(sh->evtchn_pending))) {
+ int word_idx = i / BITS_PER_EVTCHN_WORD;
+ printk(" %d: event %d -> irq %d%s%s%s\n",
+ cpu_from_evtchn(i), i,
+ evtchn_to_irq[i],
+ sync_test_bit(word_idx,
BM(&v->evtchn_pending_sel))
+ ? "" : " l2-clear",
+ !sync_test_bit(i, BM(sh->evtchn_mask))
+ ? "" : " globally-masked",
+ sync_test_bit(i, BM(cpu_evtchn))
+ ? "" : " locally-masked");
+ }
+ }
+
+ spin_unlock_irqrestore(&debug_lock, flags);
+
+ return IRQ_HANDLED;
+}
--
1.7.2.5
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