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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/xen/events
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/xen/events')
-rw-r--r--drivers/xen/events/Makefile6
-rw-r--r--drivers/xen/events/events_2l.c384
-rw-r--r--drivers/xen/events/events_base.c2333
-rw-r--r--drivers/xen/events/events_fifo.c442
-rw-r--r--drivers/xen/events/events_internal.h111
5 files changed, 3276 insertions, 0 deletions
diff --git a/drivers/xen/events/Makefile b/drivers/xen/events/Makefile
new file mode 100644
index 000000000..92508d9a6
--- /dev/null
+++ b/drivers/xen/events/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-y += events.o
+
+events-y += events_base.o
+events-y += events_2l.o
+events-y += events_fifo.o
diff --git a/drivers/xen/events/events_2l.c b/drivers/xen/events/events_2l.c
new file mode 100644
index 000000000..b8f2f971c
--- /dev/null
+++ b/drivers/xen/events/events_2l.c
@@ -0,0 +1,384 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Xen event channels (2-level ABI)
+ *
+ * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
+ */
+
+#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
+
+#include <linux/linkage.h>
+#include <linux/interrupt.h>
+#include <linux/irq.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)
+
+#define EVTCHN_MASK_SIZE (EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD)
+
+static DEFINE_PER_CPU(xen_ulong_t [EVTCHN_MASK_SIZE], cpu_evtchn_mask);
+
+static unsigned evtchn_2l_max_channels(void)
+{
+ return EVTCHN_2L_NR_CHANNELS;
+}
+
+static void evtchn_2l_remove(evtchn_port_t evtchn, unsigned int cpu)
+{
+ clear_bit(evtchn, BM(per_cpu(cpu_evtchn_mask, cpu)));
+}
+
+static void evtchn_2l_bind_to_cpu(evtchn_port_t evtchn, unsigned int cpu,
+ unsigned int old_cpu)
+{
+ clear_bit(evtchn, BM(per_cpu(cpu_evtchn_mask, old_cpu)));
+ set_bit(evtchn, BM(per_cpu(cpu_evtchn_mask, cpu)));
+}
+
+static void evtchn_2l_clear_pending(evtchn_port_t port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ sync_clear_bit(port, BM(&s->evtchn_pending[0]));
+}
+
+static void evtchn_2l_set_pending(evtchn_port_t port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ sync_set_bit(port, BM(&s->evtchn_pending[0]));
+}
+
+static bool evtchn_2l_is_pending(evtchn_port_t port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ return sync_test_bit(port, BM(&s->evtchn_pending[0]));
+}
+
+static void evtchn_2l_mask(evtchn_port_t port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ sync_set_bit(port, BM(&s->evtchn_mask[0]));
+}
+
+static void evtchn_2l_unmask(evtchn_port_t port)
+{
+ struct shared_info *s = HYPERVISOR_shared_info;
+ unsigned int cpu = get_cpu();
+ int do_hypercall = 0, evtchn_pending = 0;
+
+ BUG_ON(!irqs_disabled());
+
+ smp_wmb(); /* All writes before unmask must be visible. */
+
+ 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 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.
+ */
+static void evtchn_2l_handle_events(unsigned cpu, struct evtchn_loop_ctrl *ctrl)
+{
+ int irq;
+ xen_ulong_t pending_words;
+ xen_ulong_t pending_bits;
+ 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);
+
+ /* Timer interrupt has highest priority. */
+ irq = irq_from_virq(cpu, VIRQ_TIMER);
+ if (irq != -1) {
+ evtchn_port_t evtchn = evtchn_from_irq(irq);
+ word_idx = evtchn / BITS_PER_LONG;
+ bit_idx = evtchn % BITS_PER_LONG;
+ if (active_evtchns(cpu, s, word_idx) & (1ULL << bit_idx))
+ generic_handle_irq(irq);
+ }
+
+ /*
+ * 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 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 */
+ /*
+ * We scan the starting word in two parts.
+ *
+ * 1st time: start in the middle, scanning the
+ * upper bits.
+ *
+ * 2nd time: scan the whole word (not just the
+ * parts skipped in the first pass) -- if an
+ * event in the previously scanned bits is
+ * pending again it would just be scanned on
+ * the next loop anyway.
+ */
+ if (word_idx == start_word_idx) {
+ if (i == 0)
+ bit_idx = start_bit_idx;
+ }
+
+ do {
+ xen_ulong_t bits;
+ evtchn_port_t 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;
+ handle_irq_for_port(port, ctrl);
+
+ 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 = (EVTCHN_2L_NR_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 < EVTCHN_2L_NR_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,
+ get_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 void evtchn_2l_resume(void)
+{
+ int i;
+
+ for_each_online_cpu(i)
+ memset(per_cpu(cpu_evtchn_mask, i), 0, sizeof(xen_ulong_t) *
+ EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD);
+}
+
+static int evtchn_2l_percpu_deinit(unsigned int cpu)
+{
+ memset(per_cpu(cpu_evtchn_mask, cpu), 0, sizeof(xen_ulong_t) *
+ EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD);
+
+ return 0;
+}
+
+static const struct evtchn_ops evtchn_ops_2l = {
+ .max_channels = evtchn_2l_max_channels,
+ .nr_channels = evtchn_2l_max_channels,
+ .remove = evtchn_2l_remove,
+ .bind_to_cpu = evtchn_2l_bind_to_cpu,
+ .clear_pending = evtchn_2l_clear_pending,
+ .set_pending = evtchn_2l_set_pending,
+ .is_pending = evtchn_2l_is_pending,
+ .mask = evtchn_2l_mask,
+ .unmask = evtchn_2l_unmask,
+ .handle_events = evtchn_2l_handle_events,
+ .resume = evtchn_2l_resume,
+ .percpu_deinit = evtchn_2l_percpu_deinit,
+};
+
+void __init xen_evtchn_2l_init(void)
+{
+ pr_info("Using 2-level ABI\n");
+ evtchn_ops = &evtchn_ops_2l;
+}
diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c
new file mode 100644
index 000000000..00f8e3499
--- /dev/null
+++ b/drivers/xen/events/events_base.c
@@ -0,0 +1,2333 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * 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 received, 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. PIRQs - Hardware interrupts.
+ *
+ * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007
+ */
+
+#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
+
+#include <linux/linkage.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/moduleparam.h>
+#include <linux/string.h>
+#include <linux/memblock.h>
+#include <linux/slab.h>
+#include <linux/irqnr.h>
+#include <linux/pci.h>
+#include <linux/rcupdate.h>
+#include <linux/spinlock.h>
+#include <linux/cpuhotplug.h>
+#include <linux/atomic.h>
+#include <linux/ktime.h>
+
+#ifdef CONFIG_X86
+#include <asm/desc.h>
+#include <asm/ptrace.h>
+#include <asm/idtentry.h>
+#include <asm/irq.h>
+#include <asm/io_apic.h>
+#include <asm/i8259.h>
+#include <asm/xen/cpuid.h>
+#include <asm/xen/pci.h>
+#endif
+#include <asm/sync_bitops.h>
+#include <asm/xen/hypercall.h>
+#include <asm/xen/hypervisor.h>
+#include <xen/page.h>
+
+#include <xen/xen.h>
+#include <xen/hvm.h>
+#include <xen/xen-ops.h>
+#include <xen/events.h>
+#include <xen/interface/xen.h>
+#include <xen/interface/event_channel.h>
+#include <xen/interface/hvm/hvm_op.h>
+#include <xen/interface/hvm/params.h>
+#include <xen/interface/physdev.h>
+#include <xen/interface/sched.h>
+#include <xen/interface/vcpu.h>
+#include <xen/xenbus.h>
+#include <asm/hw_irq.h>
+
+#include "events_internal.h"
+
+#undef MODULE_PARAM_PREFIX
+#define MODULE_PARAM_PREFIX "xen."
+
+/* 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;
+ struct list_head eoi_list;
+ struct rcu_work rwork;
+ short refcnt;
+ u8 spurious_cnt;
+ u8 is_accounted;
+ short type; /* type: IRQT_* */
+ u8 mask_reason; /* Why is event channel masked */
+#define EVT_MASK_REASON_EXPLICIT 0x01
+#define EVT_MASK_REASON_TEMPORARY 0x02
+#define EVT_MASK_REASON_EOI_PENDING 0x04
+ u8 is_active; /* Is event just being handled? */
+ unsigned irq;
+ evtchn_port_t evtchn; /* event channel */
+ unsigned short cpu; /* cpu bound */
+ unsigned short eoi_cpu; /* EOI must happen on this cpu-1 */
+ unsigned int irq_epoch; /* If eoi_cpu valid: irq_epoch of event */
+ u64 eoi_time; /* Time in jiffies when to EOI. */
+ raw_spinlock_t lock;
+
+ 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;
+ struct xenbus_device *interdomain;
+ } u;
+};
+
+#define PIRQ_NEEDS_EOI (1 << 0)
+#define PIRQ_SHAREABLE (1 << 1)
+#define PIRQ_MSI_GROUP (1 << 2)
+
+static uint __read_mostly event_loop_timeout = 2;
+module_param(event_loop_timeout, uint, 0644);
+
+static uint __read_mostly event_eoi_delay = 10;
+module_param(event_eoi_delay, uint, 0644);
+
+const struct evtchn_ops *evtchn_ops;
+
+/*
+ * 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_MUTEX(irq_mapping_update_lock);
+
+/*
+ * Lock hierarchy:
+ *
+ * irq_mapping_update_lock
+ * IRQ-desc lock
+ * percpu eoi_list_lock
+ * irq_info->lock
+ */
+
+static LIST_HEAD(xen_irq_list_head);
+
+/* IRQ <-> VIRQ mapping. */
+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};
+
+/* Event channel distribution data */
+static atomic_t channels_on_cpu[NR_CPUS];
+
+static int **evtchn_to_irq;
+#ifdef CONFIG_X86
+static unsigned long *pirq_eoi_map;
+#endif
+static bool (*pirq_needs_eoi)(unsigned irq);
+
+#define EVTCHN_ROW(e) (e / (PAGE_SIZE/sizeof(**evtchn_to_irq)))
+#define EVTCHN_COL(e) (e % (PAGE_SIZE/sizeof(**evtchn_to_irq)))
+#define EVTCHN_PER_ROW (PAGE_SIZE / sizeof(**evtchn_to_irq))
+
+/* Xen will never allocate port zero for any purpose. */
+#define VALID_EVTCHN(chn) ((chn) != 0)
+
+static struct irq_info *legacy_info_ptrs[NR_IRQS_LEGACY];
+
+static struct irq_chip xen_dynamic_chip;
+static struct irq_chip xen_lateeoi_chip;
+static struct irq_chip xen_percpu_chip;
+static struct irq_chip xen_pirq_chip;
+static void enable_dynirq(struct irq_data *data);
+static void disable_dynirq(struct irq_data *data);
+
+static DEFINE_PER_CPU(unsigned int, irq_epoch);
+
+static void clear_evtchn_to_irq_row(int *evtchn_row)
+{
+ unsigned col;
+
+ for (col = 0; col < EVTCHN_PER_ROW; col++)
+ WRITE_ONCE(evtchn_row[col], -1);
+}
+
+static void clear_evtchn_to_irq_all(void)
+{
+ unsigned row;
+
+ for (row = 0; row < EVTCHN_ROW(xen_evtchn_max_channels()); row++) {
+ if (evtchn_to_irq[row] == NULL)
+ continue;
+ clear_evtchn_to_irq_row(evtchn_to_irq[row]);
+ }
+}
+
+static int set_evtchn_to_irq(evtchn_port_t evtchn, unsigned int irq)
+{
+ unsigned row;
+ unsigned col;
+ int *evtchn_row;
+
+ if (evtchn >= xen_evtchn_max_channels())
+ return -EINVAL;
+
+ row = EVTCHN_ROW(evtchn);
+ col = EVTCHN_COL(evtchn);
+
+ if (evtchn_to_irq[row] == NULL) {
+ /* Unallocated irq entries return -1 anyway */
+ if (irq == -1)
+ return 0;
+
+ evtchn_row = (int *) __get_free_pages(GFP_KERNEL, 0);
+ if (evtchn_row == NULL)
+ return -ENOMEM;
+
+ clear_evtchn_to_irq_row(evtchn_row);
+
+ /*
+ * We've prepared an empty row for the mapping. If a different
+ * thread was faster inserting it, we can drop ours.
+ */
+ if (cmpxchg(&evtchn_to_irq[row], NULL, evtchn_row) != NULL)
+ free_page((unsigned long) evtchn_row);
+ }
+
+ WRITE_ONCE(evtchn_to_irq[row][col], irq);
+ return 0;
+}
+
+int get_evtchn_to_irq(evtchn_port_t evtchn)
+{
+ if (evtchn >= xen_evtchn_max_channels())
+ return -1;
+ if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL)
+ return -1;
+ return READ_ONCE(evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)]);
+}
+
+/* Get info for IRQ */
+static struct irq_info *info_for_irq(unsigned irq)
+{
+ if (irq < nr_legacy_irqs())
+ return legacy_info_ptrs[irq];
+ else
+ return irq_get_chip_data(irq);
+}
+
+static void set_info_for_irq(unsigned int irq, struct irq_info *info)
+{
+ if (irq < nr_legacy_irqs())
+ legacy_info_ptrs[irq] = info;
+ else
+ irq_set_chip_data(irq, info);
+}
+
+/* Per CPU channel accounting */
+static void channels_on_cpu_dec(struct irq_info *info)
+{
+ if (!info->is_accounted)
+ return;
+
+ info->is_accounted = 0;
+
+ if (WARN_ON_ONCE(info->cpu >= nr_cpu_ids))
+ return;
+
+ WARN_ON_ONCE(!atomic_add_unless(&channels_on_cpu[info->cpu], -1 , 0));
+}
+
+static void channels_on_cpu_inc(struct irq_info *info)
+{
+ if (WARN_ON_ONCE(info->cpu >= nr_cpu_ids))
+ return;
+
+ if (WARN_ON_ONCE(!atomic_add_unless(&channels_on_cpu[info->cpu], 1,
+ INT_MAX)))
+ return;
+
+ info->is_accounted = 1;
+}
+
+static void delayed_free_irq(struct work_struct *work)
+{
+ struct irq_info *info = container_of(to_rcu_work(work), struct irq_info,
+ rwork);
+ unsigned int irq = info->irq;
+
+ /* Remove the info pointer only now, with no potential users left. */
+ set_info_for_irq(irq, NULL);
+
+ kfree(info);
+
+ /* Legacy IRQ descriptors are managed by the arch. */
+ if (irq >= nr_legacy_irqs())
+ irq_free_desc(irq);
+}
+
+/* Constructors for packed IRQ information. */
+static int xen_irq_info_common_setup(struct irq_info *info,
+ unsigned irq,
+ enum xen_irq_type type,
+ evtchn_port_t evtchn,
+ unsigned short cpu)
+{
+ int ret;
+
+ BUG_ON(info->type != IRQT_UNBOUND && info->type != type);
+
+ info->type = type;
+ info->irq = irq;
+ info->evtchn = evtchn;
+ info->cpu = cpu;
+ info->mask_reason = EVT_MASK_REASON_EXPLICIT;
+ raw_spin_lock_init(&info->lock);
+
+ ret = set_evtchn_to_irq(evtchn, irq);
+ if (ret < 0)
+ return ret;
+
+ irq_clear_status_flags(irq, IRQ_NOREQUEST|IRQ_NOAUTOEN);
+
+ return xen_evtchn_port_setup(evtchn);
+}
+
+static int xen_irq_info_evtchn_setup(unsigned irq,
+ evtchn_port_t evtchn,
+ struct xenbus_device *dev)
+{
+ struct irq_info *info = info_for_irq(irq);
+ int ret;
+
+ ret = xen_irq_info_common_setup(info, irq, IRQT_EVTCHN, evtchn, 0);
+ info->u.interdomain = dev;
+ if (dev)
+ atomic_inc(&dev->event_channels);
+
+ return ret;
+}
+
+static int xen_irq_info_ipi_setup(unsigned cpu,
+ unsigned irq,
+ evtchn_port_t evtchn,
+ enum ipi_vector ipi)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ info->u.ipi = ipi;
+
+ per_cpu(ipi_to_irq, cpu)[ipi] = irq;
+
+ return xen_irq_info_common_setup(info, irq, IRQT_IPI, evtchn, 0);
+}
+
+static int xen_irq_info_virq_setup(unsigned cpu,
+ unsigned irq,
+ evtchn_port_t evtchn,
+ unsigned virq)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ info->u.virq = virq;
+
+ per_cpu(virq_to_irq, cpu)[virq] = irq;
+
+ return xen_irq_info_common_setup(info, irq, IRQT_VIRQ, evtchn, 0);
+}
+
+static int xen_irq_info_pirq_setup(unsigned irq,
+ evtchn_port_t evtchn,
+ unsigned pirq,
+ unsigned gsi,
+ uint16_t domid,
+ unsigned char flags)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ info->u.pirq.pirq = pirq;
+ info->u.pirq.gsi = gsi;
+ info->u.pirq.domid = domid;
+ info->u.pirq.flags = flags;
+
+ return xen_irq_info_common_setup(info, irq, IRQT_PIRQ, evtchn, 0);
+}
+
+static void xen_irq_info_cleanup(struct irq_info *info)
+{
+ set_evtchn_to_irq(info->evtchn, -1);
+ xen_evtchn_port_remove(info->evtchn, info->cpu);
+ info->evtchn = 0;
+ channels_on_cpu_dec(info);
+}
+
+/*
+ * Accessors for packed IRQ information.
+ */
+evtchn_port_t evtchn_from_irq(unsigned irq)
+{
+ const struct irq_info *info = NULL;
+
+ if (likely(irq < nr_irqs))
+ info = info_for_irq(irq);
+ if (!info)
+ return 0;
+
+ return info->evtchn;
+}
+
+unsigned int irq_from_evtchn(evtchn_port_t evtchn)
+{
+ return get_evtchn_to_irq(evtchn);
+}
+EXPORT_SYMBOL_GPL(irq_from_evtchn);
+
+int irq_from_virq(unsigned int cpu, unsigned int virq)
+{
+ return per_cpu(virq_to_irq, cpu)[virq];
+}
+
+static enum ipi_vector ipi_from_irq(unsigned irq)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ BUG_ON(info == NULL);
+ BUG_ON(info->type != IRQT_IPI);
+
+ return info->u.ipi;
+}
+
+static unsigned virq_from_irq(unsigned irq)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ BUG_ON(info == NULL);
+ BUG_ON(info->type != IRQT_VIRQ);
+
+ return info->u.virq;
+}
+
+static unsigned pirq_from_irq(unsigned irq)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ BUG_ON(info == NULL);
+ BUG_ON(info->type != IRQT_PIRQ);
+
+ return info->u.pirq.pirq;
+}
+
+static enum xen_irq_type type_from_irq(unsigned irq)
+{
+ return info_for_irq(irq)->type;
+}
+
+static unsigned cpu_from_irq(unsigned irq)
+{
+ return info_for_irq(irq)->cpu;
+}
+
+unsigned int cpu_from_evtchn(evtchn_port_t evtchn)
+{
+ int irq = get_evtchn_to_irq(evtchn);
+ unsigned ret = 0;
+
+ if (irq != -1)
+ ret = cpu_from_irq(irq);
+
+ return ret;
+}
+
+static void do_mask(struct irq_info *info, u8 reason)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&info->lock, flags);
+
+ if (!info->mask_reason)
+ mask_evtchn(info->evtchn);
+
+ info->mask_reason |= reason;
+
+ raw_spin_unlock_irqrestore(&info->lock, flags);
+}
+
+static void do_unmask(struct irq_info *info, u8 reason)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&info->lock, flags);
+
+ info->mask_reason &= ~reason;
+
+ if (!info->mask_reason)
+ unmask_evtchn(info->evtchn);
+
+ raw_spin_unlock_irqrestore(&info->lock, flags);
+}
+
+#ifdef CONFIG_X86
+static bool pirq_check_eoi_map(unsigned irq)
+{
+ return test_bit(pirq_from_irq(irq), pirq_eoi_map);
+}
+#endif
+
+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;
+}
+
+static void bind_evtchn_to_cpu(evtchn_port_t evtchn, unsigned int cpu,
+ bool force_affinity)
+{
+ int irq = get_evtchn_to_irq(evtchn);
+ struct irq_info *info = info_for_irq(irq);
+
+ BUG_ON(irq == -1);
+
+ if (IS_ENABLED(CONFIG_SMP) && force_affinity) {
+ struct irq_data *data = irq_get_irq_data(irq);
+
+ irq_data_update_affinity(data, cpumask_of(cpu));
+ irq_data_update_effective_affinity(data, cpumask_of(cpu));
+ }
+
+ xen_evtchn_port_bind_to_cpu(evtchn, cpu, info->cpu);
+
+ channels_on_cpu_dec(info);
+ info->cpu = cpu;
+ channels_on_cpu_inc(info);
+}
+
+/**
+ * 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)
+{
+ evtchn_port_t evtchn = evtchn_from_irq(irq);
+
+ if (VALID_EVTCHN(evtchn))
+ notify_remote_via_evtchn(evtchn);
+}
+EXPORT_SYMBOL_GPL(notify_remote_via_irq);
+
+struct lateeoi_work {
+ struct delayed_work delayed;
+ spinlock_t eoi_list_lock;
+ struct list_head eoi_list;
+};
+
+static DEFINE_PER_CPU(struct lateeoi_work, lateeoi);
+
+static void lateeoi_list_del(struct irq_info *info)
+{
+ struct lateeoi_work *eoi = &per_cpu(lateeoi, info->eoi_cpu);
+ unsigned long flags;
+
+ spin_lock_irqsave(&eoi->eoi_list_lock, flags);
+ list_del_init(&info->eoi_list);
+ spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
+}
+
+static void lateeoi_list_add(struct irq_info *info)
+{
+ struct lateeoi_work *eoi = &per_cpu(lateeoi, info->eoi_cpu);
+ struct irq_info *elem;
+ u64 now = get_jiffies_64();
+ unsigned long delay;
+ unsigned long flags;
+
+ if (now < info->eoi_time)
+ delay = info->eoi_time - now;
+ else
+ delay = 1;
+
+ spin_lock_irqsave(&eoi->eoi_list_lock, flags);
+
+ elem = list_first_entry_or_null(&eoi->eoi_list, struct irq_info,
+ eoi_list);
+ if (!elem || info->eoi_time < elem->eoi_time) {
+ list_add(&info->eoi_list, &eoi->eoi_list);
+ mod_delayed_work_on(info->eoi_cpu, system_wq,
+ &eoi->delayed, delay);
+ } else {
+ list_for_each_entry_reverse(elem, &eoi->eoi_list, eoi_list) {
+ if (elem->eoi_time <= info->eoi_time)
+ break;
+ }
+ list_add(&info->eoi_list, &elem->eoi_list);
+ }
+
+ spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
+}
+
+static void xen_irq_lateeoi_locked(struct irq_info *info, bool spurious)
+{
+ evtchn_port_t evtchn;
+ unsigned int cpu;
+ unsigned int delay = 0;
+
+ evtchn = info->evtchn;
+ if (!VALID_EVTCHN(evtchn) || !list_empty(&info->eoi_list))
+ return;
+
+ if (spurious) {
+ struct xenbus_device *dev = info->u.interdomain;
+ unsigned int threshold = 1;
+
+ if (dev && dev->spurious_threshold)
+ threshold = dev->spurious_threshold;
+
+ if ((1 << info->spurious_cnt) < (HZ << 2)) {
+ if (info->spurious_cnt != 0xFF)
+ info->spurious_cnt++;
+ }
+ if (info->spurious_cnt > threshold) {
+ delay = 1 << (info->spurious_cnt - 1 - threshold);
+ if (delay > HZ)
+ delay = HZ;
+ if (!info->eoi_time)
+ info->eoi_cpu = smp_processor_id();
+ info->eoi_time = get_jiffies_64() + delay;
+ if (dev)
+ atomic_add(delay, &dev->jiffies_eoi_delayed);
+ }
+ if (dev)
+ atomic_inc(&dev->spurious_events);
+ } else {
+ info->spurious_cnt = 0;
+ }
+
+ cpu = info->eoi_cpu;
+ if (info->eoi_time &&
+ (info->irq_epoch == per_cpu(irq_epoch, cpu) || delay)) {
+ lateeoi_list_add(info);
+ return;
+ }
+
+ info->eoi_time = 0;
+
+ /* is_active hasn't been reset yet, do it now. */
+ smp_store_release(&info->is_active, 0);
+ do_unmask(info, EVT_MASK_REASON_EOI_PENDING);
+}
+
+static void xen_irq_lateeoi_worker(struct work_struct *work)
+{
+ struct lateeoi_work *eoi;
+ struct irq_info *info;
+ u64 now = get_jiffies_64();
+ unsigned long flags;
+
+ eoi = container_of(to_delayed_work(work), struct lateeoi_work, delayed);
+
+ rcu_read_lock();
+
+ while (true) {
+ spin_lock_irqsave(&eoi->eoi_list_lock, flags);
+
+ info = list_first_entry_or_null(&eoi->eoi_list, struct irq_info,
+ eoi_list);
+
+ if (info == NULL)
+ break;
+
+ if (now < info->eoi_time) {
+ mod_delayed_work_on(info->eoi_cpu, system_wq,
+ &eoi->delayed,
+ info->eoi_time - now);
+ break;
+ }
+
+ list_del_init(&info->eoi_list);
+
+ spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
+
+ info->eoi_time = 0;
+
+ xen_irq_lateeoi_locked(info, false);
+ }
+
+ spin_unlock_irqrestore(&eoi->eoi_list_lock, flags);
+
+ rcu_read_unlock();
+}
+
+static void xen_cpu_init_eoi(unsigned int cpu)
+{
+ struct lateeoi_work *eoi = &per_cpu(lateeoi, cpu);
+
+ INIT_DELAYED_WORK(&eoi->delayed, xen_irq_lateeoi_worker);
+ spin_lock_init(&eoi->eoi_list_lock);
+ INIT_LIST_HEAD(&eoi->eoi_list);
+}
+
+void xen_irq_lateeoi(unsigned int irq, unsigned int eoi_flags)
+{
+ struct irq_info *info;
+
+ rcu_read_lock();
+
+ info = info_for_irq(irq);
+
+ if (info)
+ xen_irq_lateeoi_locked(info, eoi_flags & XEN_EOI_FLAG_SPURIOUS);
+
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(xen_irq_lateeoi);
+
+static void xen_irq_init(unsigned irq)
+{
+ struct irq_info *info;
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (info == NULL)
+ panic("Unable to allocate metadata for IRQ%d\n", irq);
+
+ info->type = IRQT_UNBOUND;
+ info->refcnt = -1;
+ INIT_RCU_WORK(&info->rwork, delayed_free_irq);
+
+ set_info_for_irq(irq, info);
+ /*
+ * Interrupt affinity setting can be immediate. No point
+ * in delaying it until an interrupt is handled.
+ */
+ irq_set_status_flags(irq, IRQ_MOVE_PCNTXT);
+
+ INIT_LIST_HEAD(&info->eoi_list);
+ list_add_tail(&info->list, &xen_irq_list_head);
+}
+
+static int __must_check xen_allocate_irqs_dynamic(int nvec)
+{
+ int i, irq = irq_alloc_descs(-1, 0, nvec, -1);
+
+ if (irq >= 0) {
+ for (i = 0; i < nvec; i++)
+ xen_irq_init(irq + i);
+ }
+
+ return irq;
+}
+
+static inline int __must_check xen_allocate_irq_dynamic(void)
+{
+
+ return xen_allocate_irqs_dynamic(1);
+}
+
+static int __must_check xen_allocate_irq_gsi(unsigned gsi)
+{
+ int irq;
+
+ /*
+ * A PV guest has no concept of a GSI (since it has no ACPI
+ * nor access to/knowledge of the physical APICs). Therefore
+ * all IRQs are dynamically allocated from the entire IRQ
+ * space.
+ */
+ if (xen_pv_domain() && !xen_initial_domain())
+ return xen_allocate_irq_dynamic();
+
+ /* Legacy IRQ descriptors are already allocated by the arch. */
+ if (gsi < nr_legacy_irqs())
+ irq = gsi;
+ else
+ irq = irq_alloc_desc_at(gsi, -1);
+
+ xen_irq_init(irq);
+
+ return irq;
+}
+
+static void xen_free_irq(unsigned irq)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ if (WARN_ON(!info))
+ return;
+
+ if (!list_empty(&info->eoi_list))
+ lateeoi_list_del(info);
+
+ list_del(&info->list);
+
+ WARN_ON(info->refcnt > 0);
+
+ queue_rcu_work(system_wq, &info->rwork);
+}
+
+static void xen_evtchn_close(evtchn_port_t port)
+{
+ struct evtchn_close close;
+
+ close.port = port;
+ if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
+ BUG();
+}
+
+/* Not called for lateeoi events. */
+static void event_handler_exit(struct irq_info *info)
+{
+ smp_store_release(&info->is_active, 0);
+ clear_evtchn(info->evtchn);
+}
+
+static void pirq_query_unmask(int irq)
+{
+ struct physdev_irq_status_query irq_status;
+ struct irq_info *info = info_for_irq(irq);
+
+ BUG_ON(info->type != IRQT_PIRQ);
+
+ irq_status.irq = pirq_from_irq(irq);
+ if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
+ irq_status.flags = 0;
+
+ info->u.pirq.flags &= ~PIRQ_NEEDS_EOI;
+ if (irq_status.flags & XENIRQSTAT_needs_eoi)
+ info->u.pirq.flags |= PIRQ_NEEDS_EOI;
+}
+
+static void eoi_pirq(struct irq_data *data)
+{
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+ struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) };
+ int rc = 0;
+
+ if (!VALID_EVTCHN(evtchn))
+ return;
+
+ event_handler_exit(info);
+
+ if (pirq_needs_eoi(data->irq)) {
+ rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
+ WARN_ON(rc);
+ }
+}
+
+static void mask_ack_pirq(struct irq_data *data)
+{
+ disable_dynirq(data);
+ eoi_pirq(data);
+}
+
+static unsigned int __startup_pirq(unsigned int irq)
+{
+ struct evtchn_bind_pirq bind_pirq;
+ struct irq_info *info = info_for_irq(irq);
+ evtchn_port_t evtchn = evtchn_from_irq(irq);
+ int rc;
+
+ BUG_ON(info->type != IRQT_PIRQ);
+
+ if (VALID_EVTCHN(evtchn))
+ goto out;
+
+ bind_pirq.pirq = pirq_from_irq(irq);
+ /* NB. We are happy to share unless we are probing. */
+ bind_pirq.flags = info->u.pirq.flags & PIRQ_SHAREABLE ?
+ BIND_PIRQ__WILL_SHARE : 0;
+ rc = HYPERVISOR_event_channel_op(EVTCHNOP_bind_pirq, &bind_pirq);
+ if (rc != 0) {
+ pr_warn("Failed to obtain physical IRQ %d\n", irq);
+ return 0;
+ }
+ evtchn = bind_pirq.port;
+
+ pirq_query_unmask(irq);
+
+ rc = set_evtchn_to_irq(evtchn, irq);
+ if (rc)
+ goto err;
+
+ info->evtchn = evtchn;
+ bind_evtchn_to_cpu(evtchn, 0, false);
+
+ rc = xen_evtchn_port_setup(evtchn);
+ if (rc)
+ goto err;
+
+out:
+ do_unmask(info, EVT_MASK_REASON_EXPLICIT);
+
+ eoi_pirq(irq_get_irq_data(irq));
+
+ return 0;
+
+err:
+ pr_err("irq%d: Failed to set port to irq mapping (%d)\n", irq, rc);
+ xen_evtchn_close(evtchn);
+ return 0;
+}
+
+static unsigned int startup_pirq(struct irq_data *data)
+{
+ return __startup_pirq(data->irq);
+}
+
+static void shutdown_pirq(struct irq_data *data)
+{
+ unsigned int irq = data->irq;
+ struct irq_info *info = info_for_irq(irq);
+ evtchn_port_t evtchn = evtchn_from_irq(irq);
+
+ BUG_ON(info->type != IRQT_PIRQ);
+
+ if (!VALID_EVTCHN(evtchn))
+ return;
+
+ do_mask(info, EVT_MASK_REASON_EXPLICIT);
+ xen_evtchn_close(evtchn);
+ xen_irq_info_cleanup(info);
+}
+
+static void enable_pirq(struct irq_data *data)
+{
+ enable_dynirq(data);
+}
+
+static void disable_pirq(struct irq_data *data)
+{
+ disable_dynirq(data);
+}
+
+int xen_irq_from_gsi(unsigned gsi)
+{
+ struct irq_info *info;
+
+ list_for_each_entry(info, &xen_irq_list_head, list) {
+ if (info->type != IRQT_PIRQ)
+ continue;
+
+ if (info->u.pirq.gsi == gsi)
+ return info->irq;
+ }
+
+ return -1;
+}
+EXPORT_SYMBOL_GPL(xen_irq_from_gsi);
+
+static void __unbind_from_irq(unsigned int irq)
+{
+ evtchn_port_t evtchn = evtchn_from_irq(irq);
+ struct irq_info *info = info_for_irq(irq);
+
+ if (info->refcnt > 0) {
+ info->refcnt--;
+ if (info->refcnt != 0)
+ return;
+ }
+
+ if (VALID_EVTCHN(evtchn)) {
+ unsigned int cpu = cpu_from_irq(irq);
+ struct xenbus_device *dev;
+
+ xen_evtchn_close(evtchn);
+
+ switch (type_from_irq(irq)) {
+ case IRQT_VIRQ:
+ per_cpu(virq_to_irq, cpu)[virq_from_irq(irq)] = -1;
+ break;
+ case IRQT_IPI:
+ per_cpu(ipi_to_irq, cpu)[ipi_from_irq(irq)] = -1;
+ break;
+ case IRQT_EVTCHN:
+ dev = info->u.interdomain;
+ if (dev)
+ atomic_dec(&dev->event_channels);
+ break;
+ default:
+ break;
+ }
+
+ xen_irq_info_cleanup(info);
+ }
+
+ xen_free_irq(irq);
+}
+
+/*
+ * Do not make any assumptions regarding the relationship between the
+ * IRQ number returned here and the Xen pirq argument.
+ *
+ * Note: We don't assign an event channel until the irq actually started
+ * up. Return an existing irq if we've already got one for the gsi.
+ *
+ * Shareable implies level triggered, not shareable implies edge
+ * triggered here.
+ */
+int xen_bind_pirq_gsi_to_irq(unsigned gsi,
+ unsigned pirq, int shareable, char *name)
+{
+ int irq;
+ struct physdev_irq irq_op;
+ int ret;
+
+ mutex_lock(&irq_mapping_update_lock);
+
+ irq = xen_irq_from_gsi(gsi);
+ if (irq != -1) {
+ pr_info("%s: returning irq %d for gsi %u\n",
+ __func__, irq, gsi);
+ goto out;
+ }
+
+ irq = xen_allocate_irq_gsi(gsi);
+ if (irq < 0)
+ goto out;
+
+ irq_op.irq = irq;
+ irq_op.vector = 0;
+
+ /* Only the privileged domain can do this. For non-priv, the pcifront
+ * driver provides a PCI bus that does the call to do exactly
+ * this in the priv domain. */
+ if (xen_initial_domain() &&
+ HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op)) {
+ xen_free_irq(irq);
+ irq = -ENOSPC;
+ goto out;
+ }
+
+ ret = xen_irq_info_pirq_setup(irq, 0, pirq, gsi, DOMID_SELF,
+ shareable ? PIRQ_SHAREABLE : 0);
+ if (ret < 0) {
+ __unbind_from_irq(irq);
+ irq = ret;
+ goto out;
+ }
+
+ pirq_query_unmask(irq);
+ /* We try to use the handler with the appropriate semantic for the
+ * type of interrupt: if the interrupt is an edge triggered
+ * interrupt we use handle_edge_irq.
+ *
+ * On the other hand if the interrupt is level triggered we use
+ * handle_fasteoi_irq like the native code does for this kind of
+ * interrupts.
+ *
+ * Depending on the Xen version, pirq_needs_eoi might return true
+ * not only for level triggered interrupts but for edge triggered
+ * interrupts too. In any case Xen always honors the eoi mechanism,
+ * not injecting any more pirqs of the same kind if the first one
+ * hasn't received an eoi yet. Therefore using the fasteoi handler
+ * is the right choice either way.
+ */
+ if (shareable)
+ irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
+ handle_fasteoi_irq, name);
+ else
+ irq_set_chip_and_handler_name(irq, &xen_pirq_chip,
+ handle_edge_irq, name);
+
+out:
+ mutex_unlock(&irq_mapping_update_lock);
+
+ return irq;
+}
+
+#ifdef CONFIG_PCI_MSI
+int xen_allocate_pirq_msi(struct pci_dev *dev, struct msi_desc *msidesc)
+{
+ int rc;
+ struct physdev_get_free_pirq op_get_free_pirq;
+
+ op_get_free_pirq.type = MAP_PIRQ_TYPE_MSI;
+ rc = HYPERVISOR_physdev_op(PHYSDEVOP_get_free_pirq, &op_get_free_pirq);
+
+ WARN_ONCE(rc == -ENOSYS,
+ "hypervisor does not support the PHYSDEVOP_get_free_pirq interface\n");
+
+ return rc ? -1 : op_get_free_pirq.pirq;
+}
+
+int xen_bind_pirq_msi_to_irq(struct pci_dev *dev, struct msi_desc *msidesc,
+ int pirq, int nvec, const char *name, domid_t domid)
+{
+ int i, irq, ret;
+
+ mutex_lock(&irq_mapping_update_lock);
+
+ irq = xen_allocate_irqs_dynamic(nvec);
+ if (irq < 0)
+ goto out;
+
+ for (i = 0; i < nvec; i++) {
+ irq_set_chip_and_handler_name(irq + i, &xen_pirq_chip, handle_edge_irq, name);
+
+ ret = xen_irq_info_pirq_setup(irq + i, 0, pirq + i, 0, domid,
+ i == 0 ? 0 : PIRQ_MSI_GROUP);
+ if (ret < 0)
+ goto error_irq;
+ }
+
+ ret = irq_set_msi_desc(irq, msidesc);
+ if (ret < 0)
+ goto error_irq;
+out:
+ mutex_unlock(&irq_mapping_update_lock);
+ return irq;
+error_irq:
+ while (nvec--)
+ __unbind_from_irq(irq + nvec);
+ mutex_unlock(&irq_mapping_update_lock);
+ return ret;
+}
+#endif
+
+int xen_destroy_irq(int irq)
+{
+ struct physdev_unmap_pirq unmap_irq;
+ struct irq_info *info = info_for_irq(irq);
+ int rc = -ENOENT;
+
+ mutex_lock(&irq_mapping_update_lock);
+
+ /*
+ * If trying to remove a vector in a MSI group different
+ * than the first one skip the PIRQ unmap unless this vector
+ * is the first one in the group.
+ */
+ if (xen_initial_domain() && !(info->u.pirq.flags & PIRQ_MSI_GROUP)) {
+ unmap_irq.pirq = info->u.pirq.pirq;
+ unmap_irq.domid = info->u.pirq.domid;
+ rc = HYPERVISOR_physdev_op(PHYSDEVOP_unmap_pirq, &unmap_irq);
+ /* If another domain quits without making the pci_disable_msix
+ * call, the Xen hypervisor takes care of freeing the PIRQs
+ * (free_domain_pirqs).
+ */
+ if ((rc == -ESRCH && info->u.pirq.domid != DOMID_SELF))
+ pr_info("domain %d does not have %d anymore\n",
+ info->u.pirq.domid, info->u.pirq.pirq);
+ else if (rc) {
+ pr_warn("unmap irq failed %d\n", rc);
+ goto out;
+ }
+ }
+
+ xen_free_irq(irq);
+
+out:
+ mutex_unlock(&irq_mapping_update_lock);
+ return rc;
+}
+
+int xen_irq_from_pirq(unsigned pirq)
+{
+ int irq;
+
+ struct irq_info *info;
+
+ mutex_lock(&irq_mapping_update_lock);
+
+ list_for_each_entry(info, &xen_irq_list_head, list) {
+ if (info->type != IRQT_PIRQ)
+ continue;
+ irq = info->irq;
+ if (info->u.pirq.pirq == pirq)
+ goto out;
+ }
+ irq = -1;
+out:
+ mutex_unlock(&irq_mapping_update_lock);
+
+ return irq;
+}
+
+
+int xen_pirq_from_irq(unsigned irq)
+{
+ return pirq_from_irq(irq);
+}
+EXPORT_SYMBOL_GPL(xen_pirq_from_irq);
+
+static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip,
+ struct xenbus_device *dev)
+{
+ int irq;
+ int ret;
+
+ if (evtchn >= xen_evtchn_max_channels())
+ return -ENOMEM;
+
+ mutex_lock(&irq_mapping_update_lock);
+
+ irq = get_evtchn_to_irq(evtchn);
+
+ if (irq == -1) {
+ irq = xen_allocate_irq_dynamic();
+ if (irq < 0)
+ goto out;
+
+ irq_set_chip_and_handler_name(irq, chip,
+ handle_edge_irq, "event");
+
+ ret = xen_irq_info_evtchn_setup(irq, evtchn, dev);
+ if (ret < 0) {
+ __unbind_from_irq(irq);
+ irq = ret;
+ goto out;
+ }
+ /*
+ * New interdomain events are initially bound to vCPU0 This
+ * is required to setup the event channel in the first
+ * place and also important for UP guests because the
+ * affinity setting is not invoked on them so nothing would
+ * bind the channel.
+ */
+ bind_evtchn_to_cpu(evtchn, 0, false);
+ } else {
+ struct irq_info *info = info_for_irq(irq);
+ WARN_ON(info == NULL || info->type != IRQT_EVTCHN);
+ }
+
+out:
+ mutex_unlock(&irq_mapping_update_lock);
+
+ return irq;
+}
+
+int bind_evtchn_to_irq(evtchn_port_t evtchn)
+{
+ return bind_evtchn_to_irq_chip(evtchn, &xen_dynamic_chip, NULL);
+}
+EXPORT_SYMBOL_GPL(bind_evtchn_to_irq);
+
+int bind_evtchn_to_irq_lateeoi(evtchn_port_t evtchn)
+{
+ return bind_evtchn_to_irq_chip(evtchn, &xen_lateeoi_chip, NULL);
+}
+EXPORT_SYMBOL_GPL(bind_evtchn_to_irq_lateeoi);
+
+static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu)
+{
+ struct evtchn_bind_ipi bind_ipi;
+ evtchn_port_t evtchn;
+ int ret, irq;
+
+ mutex_lock(&irq_mapping_update_lock);
+
+ irq = per_cpu(ipi_to_irq, cpu)[ipi];
+
+ if (irq == -1) {
+ irq = xen_allocate_irq_dynamic();
+ if (irq < 0)
+ goto out;
+
+ irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
+ handle_percpu_irq, "ipi");
+
+ bind_ipi.vcpu = xen_vcpu_nr(cpu);
+ if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
+ &bind_ipi) != 0)
+ BUG();
+ evtchn = bind_ipi.port;
+
+ ret = xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
+ if (ret < 0) {
+ __unbind_from_irq(irq);
+ irq = ret;
+ goto out;
+ }
+ /*
+ * Force the affinity mask to the target CPU so proc shows
+ * the correct target.
+ */
+ bind_evtchn_to_cpu(evtchn, cpu, true);
+ } else {
+ struct irq_info *info = info_for_irq(irq);
+ WARN_ON(info == NULL || info->type != IRQT_IPI);
+ }
+
+ out:
+ mutex_unlock(&irq_mapping_update_lock);
+ return irq;
+}
+
+static int bind_interdomain_evtchn_to_irq_chip(struct xenbus_device *dev,
+ evtchn_port_t remote_port,
+ struct irq_chip *chip)
+{
+ struct evtchn_bind_interdomain bind_interdomain;
+ int err;
+
+ bind_interdomain.remote_dom = dev->otherend_id;
+ bind_interdomain.remote_port = remote_port;
+
+ err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain,
+ &bind_interdomain);
+
+ return err ? : bind_evtchn_to_irq_chip(bind_interdomain.local_port,
+ chip, dev);
+}
+
+int bind_interdomain_evtchn_to_irq_lateeoi(struct xenbus_device *dev,
+ evtchn_port_t remote_port)
+{
+ return bind_interdomain_evtchn_to_irq_chip(dev, remote_port,
+ &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq_lateeoi);
+
+static int find_virq(unsigned int virq, unsigned int cpu, evtchn_port_t *evtchn)
+{
+ struct evtchn_status status;
+ evtchn_port_t port;
+ int rc = -ENOENT;
+
+ memset(&status, 0, sizeof(status));
+ for (port = 0; port < xen_evtchn_max_channels(); port++) {
+ status.dom = DOMID_SELF;
+ status.port = port;
+ rc = HYPERVISOR_event_channel_op(EVTCHNOP_status, &status);
+ if (rc < 0)
+ continue;
+ if (status.status != EVTCHNSTAT_virq)
+ continue;
+ if (status.u.virq == virq && status.vcpu == xen_vcpu_nr(cpu)) {
+ *evtchn = port;
+ break;
+ }
+ }
+ return rc;
+}
+
+/**
+ * xen_evtchn_nr_channels - number of usable event channel ports
+ *
+ * This may be less than the maximum supported by the current
+ * hypervisor ABI. Use xen_evtchn_max_channels() for the maximum
+ * supported.
+ */
+unsigned xen_evtchn_nr_channels(void)
+{
+ return evtchn_ops->nr_channels();
+}
+EXPORT_SYMBOL_GPL(xen_evtchn_nr_channels);
+
+int bind_virq_to_irq(unsigned int virq, unsigned int cpu, bool percpu)
+{
+ struct evtchn_bind_virq bind_virq;
+ evtchn_port_t evtchn = 0;
+ int irq, ret;
+
+ mutex_lock(&irq_mapping_update_lock);
+
+ irq = per_cpu(virq_to_irq, cpu)[virq];
+
+ if (irq == -1) {
+ irq = xen_allocate_irq_dynamic();
+ if (irq < 0)
+ goto out;
+
+ if (percpu)
+ irq_set_chip_and_handler_name(irq, &xen_percpu_chip,
+ handle_percpu_irq, "virq");
+ else
+ irq_set_chip_and_handler_name(irq, &xen_dynamic_chip,
+ handle_edge_irq, "virq");
+
+ bind_virq.virq = virq;
+ bind_virq.vcpu = xen_vcpu_nr(cpu);
+ ret = HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
+ &bind_virq);
+ if (ret == 0)
+ evtchn = bind_virq.port;
+ else {
+ if (ret == -EEXIST)
+ ret = find_virq(virq, cpu, &evtchn);
+ BUG_ON(ret < 0);
+ }
+
+ ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
+ if (ret < 0) {
+ __unbind_from_irq(irq);
+ irq = ret;
+ goto out;
+ }
+
+ /*
+ * Force the affinity mask for percpu interrupts so proc
+ * shows the correct target.
+ */
+ bind_evtchn_to_cpu(evtchn, cpu, percpu);
+ } else {
+ struct irq_info *info = info_for_irq(irq);
+ WARN_ON(info == NULL || info->type != IRQT_VIRQ);
+ }
+
+out:
+ mutex_unlock(&irq_mapping_update_lock);
+
+ return irq;
+}
+
+static void unbind_from_irq(unsigned int irq)
+{
+ mutex_lock(&irq_mapping_update_lock);
+ __unbind_from_irq(irq);
+ mutex_unlock(&irq_mapping_update_lock);
+}
+
+static int bind_evtchn_to_irqhandler_chip(evtchn_port_t evtchn,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname, void *dev_id,
+ struct irq_chip *chip)
+{
+ int irq, retval;
+
+ irq = bind_evtchn_to_irq_chip(evtchn, chip, NULL);
+ 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;
+}
+
+int bind_evtchn_to_irqhandler(evtchn_port_t evtchn,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname, void *dev_id)
+{
+ return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags,
+ devname, dev_id,
+ &xen_dynamic_chip);
+}
+EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler);
+
+int bind_evtchn_to_irqhandler_lateeoi(evtchn_port_t evtchn,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname, void *dev_id)
+{
+ return bind_evtchn_to_irqhandler_chip(evtchn, handler, irqflags,
+ devname, dev_id,
+ &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_evtchn_to_irqhandler_lateeoi);
+
+static int bind_interdomain_evtchn_to_irqhandler_chip(
+ struct xenbus_device *dev, evtchn_port_t remote_port,
+ irq_handler_t handler, unsigned long irqflags,
+ const char *devname, void *dev_id, struct irq_chip *chip)
+{
+ int irq, retval;
+
+ irq = bind_interdomain_evtchn_to_irq_chip(dev, remote_port, chip);
+ 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;
+}
+
+int bind_interdomain_evtchn_to_irqhandler_lateeoi(struct xenbus_device *dev,
+ evtchn_port_t remote_port,
+ irq_handler_t handler,
+ unsigned long irqflags,
+ const char *devname,
+ void *dev_id)
+{
+ return bind_interdomain_evtchn_to_irqhandler_chip(dev,
+ remote_port, handler, irqflags, devname,
+ dev_id, &xen_lateeoi_chip);
+}
+EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irqhandler_lateeoi);
+
+int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu,
+ irq_handler_t handler,
+ unsigned long irqflags, const char *devname, void *dev_id)
+{
+ int irq, retval;
+
+ irq = bind_virq_to_irq(virq, cpu, irqflags & IRQF_PERCPU);
+ 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;
+}
+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;
+
+ irqflags |= IRQF_NO_SUSPEND | IRQF_FORCE_RESUME | IRQF_EARLY_RESUME;
+ 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)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ if (WARN_ON(!info))
+ return;
+ free_irq(irq, dev_id);
+ unbind_from_irq(irq);
+}
+EXPORT_SYMBOL_GPL(unbind_from_irqhandler);
+
+/**
+ * xen_set_irq_priority() - set an event channel priority.
+ * @irq:irq bound to an event channel.
+ * @priority: priority between XEN_IRQ_PRIORITY_MAX and XEN_IRQ_PRIORITY_MIN.
+ */
+int xen_set_irq_priority(unsigned irq, unsigned priority)
+{
+ struct evtchn_set_priority set_priority;
+
+ set_priority.port = evtchn_from_irq(irq);
+ set_priority.priority = priority;
+
+ return HYPERVISOR_event_channel_op(EVTCHNOP_set_priority,
+ &set_priority);
+}
+EXPORT_SYMBOL_GPL(xen_set_irq_priority);
+
+int evtchn_make_refcounted(evtchn_port_t evtchn)
+{
+ int irq = get_evtchn_to_irq(evtchn);
+ struct irq_info *info;
+
+ if (irq == -1)
+ return -ENOENT;
+
+ info = info_for_irq(irq);
+
+ if (!info)
+ return -ENOENT;
+
+ WARN_ON(info->refcnt != -1);
+
+ info->refcnt = 1;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(evtchn_make_refcounted);
+
+int evtchn_get(evtchn_port_t evtchn)
+{
+ int irq;
+ struct irq_info *info;
+ int err = -ENOENT;
+
+ if (evtchn >= xen_evtchn_max_channels())
+ return -EINVAL;
+
+ mutex_lock(&irq_mapping_update_lock);
+
+ irq = get_evtchn_to_irq(evtchn);
+ if (irq == -1)
+ goto done;
+
+ info = info_for_irq(irq);
+
+ if (!info)
+ goto done;
+
+ err = -EINVAL;
+ if (info->refcnt <= 0 || info->refcnt == SHRT_MAX)
+ goto done;
+
+ info->refcnt++;
+ err = 0;
+ done:
+ mutex_unlock(&irq_mapping_update_lock);
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(evtchn_get);
+
+void evtchn_put(evtchn_port_t evtchn)
+{
+ int irq = get_evtchn_to_irq(evtchn);
+ if (WARN_ON(irq == -1))
+ return;
+ unbind_from_irq(irq);
+}
+EXPORT_SYMBOL_GPL(evtchn_put);
+
+void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
+{
+ int irq;
+
+#ifdef CONFIG_X86
+ if (unlikely(vector == XEN_NMI_VECTOR)) {
+ int rc = HYPERVISOR_vcpu_op(VCPUOP_send_nmi, xen_vcpu_nr(cpu),
+ NULL);
+ if (rc < 0)
+ printk(KERN_WARNING "Sending nmi to CPU%d failed (rc:%d)\n", cpu, rc);
+ return;
+ }
+#endif
+ irq = per_cpu(ipi_to_irq, cpu)[vector];
+ BUG_ON(irq < 0);
+ notify_remote_via_irq(irq);
+}
+
+struct evtchn_loop_ctrl {
+ ktime_t timeout;
+ unsigned count;
+ bool defer_eoi;
+};
+
+void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl)
+{
+ int irq;
+ struct irq_info *info;
+ struct xenbus_device *dev;
+
+ irq = get_evtchn_to_irq(port);
+ if (irq == -1)
+ return;
+
+ /*
+ * Check for timeout every 256 events.
+ * We are setting the timeout value only after the first 256
+ * events in order to not hurt the common case of few loop
+ * iterations. The 256 is basically an arbitrary value.
+ *
+ * In case we are hitting the timeout we need to defer all further
+ * EOIs in order to ensure to leave the event handling loop rather
+ * sooner than later.
+ */
+ if (!ctrl->defer_eoi && !(++ctrl->count & 0xff)) {
+ ktime_t kt = ktime_get();
+
+ if (!ctrl->timeout) {
+ kt = ktime_add_ms(kt,
+ jiffies_to_msecs(event_loop_timeout));
+ ctrl->timeout = kt;
+ } else if (kt > ctrl->timeout) {
+ ctrl->defer_eoi = true;
+ }
+ }
+
+ info = info_for_irq(irq);
+ if (xchg_acquire(&info->is_active, 1))
+ return;
+
+ dev = (info->type == IRQT_EVTCHN) ? info->u.interdomain : NULL;
+ if (dev)
+ atomic_inc(&dev->events);
+
+ if (ctrl->defer_eoi) {
+ info->eoi_cpu = smp_processor_id();
+ info->irq_epoch = __this_cpu_read(irq_epoch);
+ info->eoi_time = get_jiffies_64() + event_eoi_delay;
+ }
+
+ generic_handle_irq(irq);
+}
+
+int xen_evtchn_do_upcall(void)
+{
+ struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu);
+ int ret = vcpu_info->evtchn_upcall_pending ? IRQ_HANDLED : IRQ_NONE;
+ int cpu = smp_processor_id();
+ struct evtchn_loop_ctrl ctrl = { 0 };
+
+ /*
+ * When closing an event channel the associated IRQ must not be freed
+ * until all cpus have left the event handling loop. This is ensured
+ * by taking the rcu_read_lock() while handling events, as freeing of
+ * the IRQ is handled via queue_rcu_work() _after_ closing the event
+ * channel.
+ */
+ rcu_read_lock();
+
+ do {
+ vcpu_info->evtchn_upcall_pending = 0;
+
+ xen_evtchn_handle_events(cpu, &ctrl);
+
+ BUG_ON(!irqs_disabled());
+
+ virt_rmb(); /* Hypervisor can set upcall pending. */
+
+ } while (vcpu_info->evtchn_upcall_pending);
+
+ rcu_read_unlock();
+
+ /*
+ * Increment irq_epoch only now to defer EOIs only for
+ * xen_irq_lateeoi() invocations occurring from inside the loop
+ * above.
+ */
+ __this_cpu_inc(irq_epoch);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(xen_evtchn_do_upcall);
+
+/* Rebind a new event channel to an existing irq. */
+void rebind_evtchn_irq(evtchn_port_t evtchn, int irq)
+{
+ struct irq_info *info = info_for_irq(irq);
+
+ if (WARN_ON(!info))
+ return;
+
+ /* Make sure the irq is masked, since the new event channel
+ will also be masked. */
+ disable_irq(irq);
+
+ mutex_lock(&irq_mapping_update_lock);
+
+ /* After resume the irq<->evtchn mappings are all cleared out */
+ BUG_ON(get_evtchn_to_irq(evtchn) != -1);
+ /* Expect irq to have been bound before,
+ so there should be a proper type */
+ BUG_ON(info->type == IRQT_UNBOUND);
+
+ (void)xen_irq_info_evtchn_setup(irq, evtchn, NULL);
+
+ mutex_unlock(&irq_mapping_update_lock);
+
+ bind_evtchn_to_cpu(evtchn, info->cpu, false);
+
+ /* Unmask the event channel. */
+ enable_irq(irq);
+}
+
+/* Rebind an evtchn so that it gets delivered to a specific cpu */
+static int xen_rebind_evtchn_to_cpu(struct irq_info *info, unsigned int tcpu)
+{
+ struct evtchn_bind_vcpu bind_vcpu;
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+ if (!VALID_EVTCHN(evtchn))
+ return -1;
+
+ if (!xen_support_evtchn_rebind())
+ return -1;
+
+ /* Send future instances of this interrupt to other vcpu. */
+ bind_vcpu.port = evtchn;
+ bind_vcpu.vcpu = xen_vcpu_nr(tcpu);
+
+ /*
+ * Mask the event while changing the VCPU binding to prevent
+ * it being delivered on an unexpected VCPU.
+ */
+ do_mask(info, EVT_MASK_REASON_TEMPORARY);
+
+ /*
+ * 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, false);
+
+ do_unmask(info, EVT_MASK_REASON_TEMPORARY);
+
+ return 0;
+}
+
+/*
+ * Find the CPU within @dest mask which has the least number of channels
+ * assigned. This is not precise as the per cpu counts can be modified
+ * concurrently.
+ */
+static unsigned int select_target_cpu(const struct cpumask *dest)
+{
+ unsigned int cpu, best_cpu = UINT_MAX, minch = UINT_MAX;
+
+ for_each_cpu_and(cpu, dest, cpu_online_mask) {
+ unsigned int curch = atomic_read(&channels_on_cpu[cpu]);
+
+ if (curch < minch) {
+ minch = curch;
+ best_cpu = cpu;
+ }
+ }
+
+ /*
+ * Catch the unlikely case that dest contains no online CPUs. Can't
+ * recurse.
+ */
+ if (best_cpu == UINT_MAX)
+ return select_target_cpu(cpu_online_mask);
+
+ return best_cpu;
+}
+
+static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
+ bool force)
+{
+ unsigned int tcpu = select_target_cpu(dest);
+ int ret;
+
+ ret = xen_rebind_evtchn_to_cpu(info_for_irq(data->irq), tcpu);
+ if (!ret)
+ irq_data_update_effective_affinity(data, cpumask_of(tcpu));
+
+ return ret;
+}
+
+static void enable_dynirq(struct irq_data *data)
+{
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+ if (VALID_EVTCHN(evtchn))
+ do_unmask(info, EVT_MASK_REASON_EXPLICIT);
+}
+
+static void disable_dynirq(struct irq_data *data)
+{
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+ if (VALID_EVTCHN(evtchn))
+ do_mask(info, EVT_MASK_REASON_EXPLICIT);
+}
+
+static void ack_dynirq(struct irq_data *data)
+{
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+ if (VALID_EVTCHN(evtchn))
+ event_handler_exit(info);
+}
+
+static void mask_ack_dynirq(struct irq_data *data)
+{
+ disable_dynirq(data);
+ ack_dynirq(data);
+}
+
+static void lateeoi_ack_dynirq(struct irq_data *data)
+{
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+ if (VALID_EVTCHN(evtchn)) {
+ do_mask(info, EVT_MASK_REASON_EOI_PENDING);
+ /*
+ * Don't call event_handler_exit().
+ * Need to keep is_active non-zero in order to ignore re-raised
+ * events after cpu affinity changes while a lateeoi is pending.
+ */
+ clear_evtchn(evtchn);
+ }
+}
+
+static void lateeoi_mask_ack_dynirq(struct irq_data *data)
+{
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+ if (VALID_EVTCHN(evtchn)) {
+ do_mask(info, EVT_MASK_REASON_EXPLICIT);
+ event_handler_exit(info);
+ }
+}
+
+static int retrigger_dynirq(struct irq_data *data)
+{
+ struct irq_info *info = info_for_irq(data->irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+ if (!VALID_EVTCHN(evtchn))
+ return 0;
+
+ do_mask(info, EVT_MASK_REASON_TEMPORARY);
+ set_evtchn(evtchn);
+ do_unmask(info, EVT_MASK_REASON_TEMPORARY);
+
+ return 1;
+}
+
+static void restore_pirqs(void)
+{
+ int pirq, rc, irq, gsi;
+ struct physdev_map_pirq map_irq;
+ struct irq_info *info;
+
+ list_for_each_entry(info, &xen_irq_list_head, list) {
+ if (info->type != IRQT_PIRQ)
+ continue;
+
+ pirq = info->u.pirq.pirq;
+ gsi = info->u.pirq.gsi;
+ irq = info->irq;
+
+ /* save/restore of PT devices doesn't work, so at this point the
+ * only devices present are GSI based emulated devices */
+ if (!gsi)
+ continue;
+
+ map_irq.domid = DOMID_SELF;
+ map_irq.type = MAP_PIRQ_TYPE_GSI;
+ map_irq.index = gsi;
+ map_irq.pirq = pirq;
+
+ rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
+ if (rc) {
+ pr_warn("xen map irq failed gsi=%d irq=%d pirq=%d rc=%d\n",
+ gsi, irq, pirq, rc);
+ xen_free_irq(irq);
+ continue;
+ }
+
+ printk(KERN_DEBUG "xen: --> irq=%d, pirq=%d\n", irq, map_irq.pirq);
+
+ __startup_pirq(irq);
+ }
+}
+
+static void restore_cpu_virqs(unsigned int cpu)
+{
+ struct evtchn_bind_virq bind_virq;
+ evtchn_port_t evtchn;
+ int virq, irq;
+
+ for (virq = 0; virq < NR_VIRQS; virq++) {
+ if ((irq = per_cpu(virq_to_irq, cpu)[virq]) == -1)
+ continue;
+
+ BUG_ON(virq_from_irq(irq) != virq);
+
+ /* Get a new binding from Xen. */
+ bind_virq.virq = virq;
+ bind_virq.vcpu = xen_vcpu_nr(cpu);
+ if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_virq,
+ &bind_virq) != 0)
+ BUG();
+ evtchn = bind_virq.port;
+
+ /* Record the new mapping. */
+ (void)xen_irq_info_virq_setup(cpu, irq, evtchn, virq);
+ /* The affinity mask is still valid */
+ bind_evtchn_to_cpu(evtchn, cpu, false);
+ }
+}
+
+static void restore_cpu_ipis(unsigned int cpu)
+{
+ struct evtchn_bind_ipi bind_ipi;
+ evtchn_port_t evtchn;
+ int ipi, irq;
+
+ for (ipi = 0; ipi < XEN_NR_IPIS; ipi++) {
+ if ((irq = per_cpu(ipi_to_irq, cpu)[ipi]) == -1)
+ continue;
+
+ BUG_ON(ipi_from_irq(irq) != ipi);
+
+ /* Get a new binding from Xen. */
+ bind_ipi.vcpu = xen_vcpu_nr(cpu);
+ if (HYPERVISOR_event_channel_op(EVTCHNOP_bind_ipi,
+ &bind_ipi) != 0)
+ BUG();
+ evtchn = bind_ipi.port;
+
+ /* Record the new mapping. */
+ (void)xen_irq_info_ipi_setup(cpu, irq, evtchn, ipi);
+ /* The affinity mask is still valid */
+ bind_evtchn_to_cpu(evtchn, cpu, false);
+ }
+}
+
+/* Clear an irq's pending state, in preparation for polling on it */
+void xen_clear_irq_pending(int irq)
+{
+ struct irq_info *info = info_for_irq(irq);
+ evtchn_port_t evtchn = info ? info->evtchn : 0;
+
+ if (VALID_EVTCHN(evtchn))
+ event_handler_exit(info);
+}
+EXPORT_SYMBOL(xen_clear_irq_pending);
+void xen_set_irq_pending(int irq)
+{
+ evtchn_port_t evtchn = evtchn_from_irq(irq);
+
+ if (VALID_EVTCHN(evtchn))
+ set_evtchn(evtchn);
+}
+
+bool xen_test_irq_pending(int irq)
+{
+ evtchn_port_t evtchn = evtchn_from_irq(irq);
+ bool ret = false;
+
+ if (VALID_EVTCHN(evtchn))
+ ret = test_evtchn(evtchn);
+
+ return ret;
+}
+
+/* Poll waiting for an irq to become pending with timeout. In the usual case,
+ * the irq will be disabled so it won't deliver an interrupt. */
+void xen_poll_irq_timeout(int irq, u64 timeout)
+{
+ evtchn_port_t evtchn = evtchn_from_irq(irq);
+
+ if (VALID_EVTCHN(evtchn)) {
+ struct sched_poll poll;
+
+ poll.nr_ports = 1;
+ poll.timeout = timeout;
+ set_xen_guest_handle(poll.ports, &evtchn);
+
+ if (HYPERVISOR_sched_op(SCHEDOP_poll, &poll) != 0)
+ BUG();
+ }
+}
+EXPORT_SYMBOL(xen_poll_irq_timeout);
+/* Poll waiting for an irq to become pending. In the usual case, the
+ * irq will be disabled so it won't deliver an interrupt. */
+void xen_poll_irq(int irq)
+{
+ xen_poll_irq_timeout(irq, 0 /* no timeout */);
+}
+
+/* Check whether the IRQ line is shared with other guests. */
+int xen_test_irq_shared(int irq)
+{
+ struct irq_info *info = info_for_irq(irq);
+ struct physdev_irq_status_query irq_status;
+
+ if (WARN_ON(!info))
+ return -ENOENT;
+
+ irq_status.irq = info->u.pirq.pirq;
+
+ if (HYPERVISOR_physdev_op(PHYSDEVOP_irq_status_query, &irq_status))
+ return 0;
+ return !(irq_status.flags & XENIRQSTAT_shared);
+}
+EXPORT_SYMBOL_GPL(xen_test_irq_shared);
+
+void xen_irq_resume(void)
+{
+ unsigned int cpu;
+ struct irq_info *info;
+
+ /* New event-channel space is not 'live' yet. */
+ xen_evtchn_resume();
+
+ /* No IRQ <-> event-channel mappings. */
+ list_for_each_entry(info, &xen_irq_list_head, list) {
+ /* Zap event-channel binding */
+ info->evtchn = 0;
+ /* Adjust accounting */
+ channels_on_cpu_dec(info);
+ }
+
+ clear_evtchn_to_irq_all();
+
+ for_each_possible_cpu(cpu) {
+ restore_cpu_virqs(cpu);
+ restore_cpu_ipis(cpu);
+ }
+
+ restore_pirqs();
+}
+
+static struct irq_chip xen_dynamic_chip __read_mostly = {
+ .name = "xen-dyn",
+
+ .irq_disable = disable_dynirq,
+ .irq_mask = disable_dynirq,
+ .irq_unmask = enable_dynirq,
+
+ .irq_ack = ack_dynirq,
+ .irq_mask_ack = mask_ack_dynirq,
+
+ .irq_set_affinity = set_affinity_irq,
+ .irq_retrigger = retrigger_dynirq,
+};
+
+static struct irq_chip xen_lateeoi_chip __read_mostly = {
+ /* The chip name needs to contain "xen-dyn" for irqbalance to work. */
+ .name = "xen-dyn-lateeoi",
+
+ .irq_disable = disable_dynirq,
+ .irq_mask = disable_dynirq,
+ .irq_unmask = enable_dynirq,
+
+ .irq_ack = lateeoi_ack_dynirq,
+ .irq_mask_ack = lateeoi_mask_ack_dynirq,
+
+ .irq_set_affinity = set_affinity_irq,
+ .irq_retrigger = retrigger_dynirq,
+};
+
+static struct irq_chip xen_pirq_chip __read_mostly = {
+ .name = "xen-pirq",
+
+ .irq_startup = startup_pirq,
+ .irq_shutdown = shutdown_pirq,
+ .irq_enable = enable_pirq,
+ .irq_disable = disable_pirq,
+
+ .irq_mask = disable_dynirq,
+ .irq_unmask = enable_dynirq,
+
+ .irq_ack = eoi_pirq,
+ .irq_eoi = eoi_pirq,
+ .irq_mask_ack = mask_ack_pirq,
+
+ .irq_set_affinity = set_affinity_irq,
+
+ .irq_retrigger = retrigger_dynirq,
+};
+
+static struct irq_chip xen_percpu_chip __read_mostly = {
+ .name = "xen-percpu",
+
+ .irq_disable = disable_dynirq,
+ .irq_mask = disable_dynirq,
+ .irq_unmask = enable_dynirq,
+
+ .irq_ack = ack_dynirq,
+};
+
+#ifdef CONFIG_X86
+#ifdef CONFIG_XEN_PVHVM
+/* Vector callbacks are better than PCI interrupts to receive event
+ * channel notifications because we can receive vector callbacks on any
+ * vcpu and we don't need PCI support or APIC interactions. */
+void xen_setup_callback_vector(void)
+{
+ uint64_t callback_via;
+
+ if (xen_have_vector_callback) {
+ callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR);
+ if (xen_set_callback_via(callback_via)) {
+ pr_err("Request for Xen HVM callback vector failed\n");
+ xen_have_vector_callback = false;
+ }
+ }
+}
+
+/*
+ * Setup per-vCPU vector-type callbacks. If this setup is unavailable,
+ * fallback to the global vector-type callback.
+ */
+static __init void xen_init_setup_upcall_vector(void)
+{
+ if (!xen_have_vector_callback)
+ return;
+
+ if ((cpuid_eax(xen_cpuid_base() + 4) & XEN_HVM_CPUID_UPCALL_VECTOR) &&
+ !xen_set_upcall_vector(0))
+ xen_percpu_upcall = true;
+ else if (xen_feature(XENFEAT_hvm_callback_vector))
+ xen_setup_callback_vector();
+ else
+ xen_have_vector_callback = false;
+}
+
+int xen_set_upcall_vector(unsigned int cpu)
+{
+ int rc;
+ xen_hvm_evtchn_upcall_vector_t op = {
+ .vector = HYPERVISOR_CALLBACK_VECTOR,
+ .vcpu = per_cpu(xen_vcpu_id, cpu),
+ };
+
+ rc = HYPERVISOR_hvm_op(HVMOP_set_evtchn_upcall_vector, &op);
+ if (rc)
+ return rc;
+
+ /* Trick toolstack to think we are enlightened. */
+ if (!cpu)
+ rc = xen_set_callback_via(1);
+
+ return rc;
+}
+
+static __init void xen_alloc_callback_vector(void)
+{
+ if (!xen_have_vector_callback)
+ return;
+
+ pr_info("Xen HVM callback vector for event delivery is enabled\n");
+ alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, asm_sysvec_xen_hvm_callback);
+}
+#else
+void xen_setup_callback_vector(void) {}
+static inline void xen_init_setup_upcall_vector(void) {}
+int xen_set_upcall_vector(unsigned int cpu) {}
+static inline void xen_alloc_callback_vector(void) {}
+#endif /* CONFIG_XEN_PVHVM */
+#endif /* CONFIG_X86 */
+
+bool xen_fifo_events = true;
+module_param_named(fifo_events, xen_fifo_events, bool, 0);
+
+static int xen_evtchn_cpu_prepare(unsigned int cpu)
+{
+ int ret = 0;
+
+ xen_cpu_init_eoi(cpu);
+
+ if (evtchn_ops->percpu_init)
+ ret = evtchn_ops->percpu_init(cpu);
+
+ return ret;
+}
+
+static int xen_evtchn_cpu_dead(unsigned int cpu)
+{
+ int ret = 0;
+
+ if (evtchn_ops->percpu_deinit)
+ ret = evtchn_ops->percpu_deinit(cpu);
+
+ return ret;
+}
+
+void __init xen_init_IRQ(void)
+{
+ int ret = -EINVAL;
+ evtchn_port_t evtchn;
+
+ if (xen_fifo_events)
+ ret = xen_evtchn_fifo_init();
+ if (ret < 0) {
+ xen_evtchn_2l_init();
+ xen_fifo_events = false;
+ }
+
+ xen_cpu_init_eoi(smp_processor_id());
+
+ cpuhp_setup_state_nocalls(CPUHP_XEN_EVTCHN_PREPARE,
+ "xen/evtchn:prepare",
+ xen_evtchn_cpu_prepare, xen_evtchn_cpu_dead);
+
+ evtchn_to_irq = kcalloc(EVTCHN_ROW(xen_evtchn_max_channels()),
+ sizeof(*evtchn_to_irq), GFP_KERNEL);
+ BUG_ON(!evtchn_to_irq);
+
+ /* No event channels are 'live' right now. */
+ for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++)
+ mask_evtchn(evtchn);
+
+ pirq_needs_eoi = pirq_needs_eoi_flag;
+
+#ifdef CONFIG_X86
+ if (xen_pv_domain()) {
+ if (xen_initial_domain())
+ pci_xen_initial_domain();
+ }
+ xen_init_setup_upcall_vector();
+ xen_alloc_callback_vector();
+
+
+ if (xen_hvm_domain()) {
+ native_init_IRQ();
+ /* pci_xen_hvm_init must be called after native_init_IRQ so that
+ * __acpi_register_gsi can point at the right function */
+ pci_xen_hvm_init();
+ } else {
+ int rc;
+ struct physdev_pirq_eoi_gmfn eoi_gmfn;
+
+ pirq_eoi_map = (void *)__get_free_page(GFP_KERNEL|__GFP_ZERO);
+ eoi_gmfn.gmfn = virt_to_gfn(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;
+ }
+#endif
+}
diff --git a/drivers/xen/events/events_fifo.c b/drivers/xen/events/events_fifo.c
new file mode 100644
index 000000000..ad9fe51d3
--- /dev/null
+++ b/drivers/xen/events/events_fifo.c
@@ -0,0 +1,442 @@
+/*
+ * Xen event channels (FIFO-based ABI)
+ *
+ * Copyright (C) 2013 Citrix Systems R&D ltd.
+ *
+ * This source code is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * Or, when distributed separately from the Linux kernel or
+ * incorporated into other software packages, subject to the following
+ * license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
+
+#include <linux/linkage.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/smp.h>
+#include <linux/percpu.h>
+#include <linux/cpu.h>
+
+#include <asm/barrier.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 <xen/page.h>
+
+#include "events_internal.h"
+
+#define EVENT_WORDS_PER_PAGE (XEN_PAGE_SIZE / sizeof(event_word_t))
+#define MAX_EVENT_ARRAY_PAGES (EVTCHN_FIFO_NR_CHANNELS / EVENT_WORDS_PER_PAGE)
+
+struct evtchn_fifo_queue {
+ uint32_t head[EVTCHN_FIFO_MAX_QUEUES];
+};
+
+static DEFINE_PER_CPU(struct evtchn_fifo_control_block *, cpu_control_block);
+static DEFINE_PER_CPU(struct evtchn_fifo_queue, cpu_queue);
+static event_word_t *event_array[MAX_EVENT_ARRAY_PAGES] __read_mostly;
+static unsigned event_array_pages __read_mostly;
+
+/*
+ * sync_set_bit() and friends must be unsigned long aligned.
+ */
+#if BITS_PER_LONG > 32
+
+#define BM(w) (unsigned long *)((unsigned long)w & ~0x7UL)
+#define EVTCHN_FIFO_BIT(b, w) \
+ (((unsigned long)w & 0x4UL) ? (EVTCHN_FIFO_ ##b + 32) : EVTCHN_FIFO_ ##b)
+
+#else
+
+#define BM(w) ((unsigned long *)(w))
+#define EVTCHN_FIFO_BIT(b, w) EVTCHN_FIFO_ ##b
+
+#endif
+
+static inline event_word_t *event_word_from_port(evtchn_port_t port)
+{
+ unsigned i = port / EVENT_WORDS_PER_PAGE;
+
+ return event_array[i] + port % EVENT_WORDS_PER_PAGE;
+}
+
+static unsigned evtchn_fifo_max_channels(void)
+{
+ return EVTCHN_FIFO_NR_CHANNELS;
+}
+
+static unsigned evtchn_fifo_nr_channels(void)
+{
+ return event_array_pages * EVENT_WORDS_PER_PAGE;
+}
+
+static int init_control_block(int cpu,
+ struct evtchn_fifo_control_block *control_block)
+{
+ struct evtchn_fifo_queue *q = &per_cpu(cpu_queue, cpu);
+ struct evtchn_init_control init_control;
+ unsigned int i;
+
+ /* Reset the control block and the local HEADs. */
+ clear_page(control_block);
+ for (i = 0; i < EVTCHN_FIFO_MAX_QUEUES; i++)
+ q->head[i] = 0;
+
+ init_control.control_gfn = virt_to_gfn(control_block);
+ init_control.offset = 0;
+ init_control.vcpu = xen_vcpu_nr(cpu);
+
+ return HYPERVISOR_event_channel_op(EVTCHNOP_init_control, &init_control);
+}
+
+static void free_unused_array_pages(void)
+{
+ unsigned i;
+
+ for (i = event_array_pages; i < MAX_EVENT_ARRAY_PAGES; i++) {
+ if (!event_array[i])
+ break;
+ free_page((unsigned long)event_array[i]);
+ event_array[i] = NULL;
+ }
+}
+
+static void init_array_page(event_word_t *array_page)
+{
+ unsigned i;
+
+ for (i = 0; i < EVENT_WORDS_PER_PAGE; i++)
+ array_page[i] = 1 << EVTCHN_FIFO_MASKED;
+}
+
+static int evtchn_fifo_setup(evtchn_port_t port)
+{
+ unsigned new_array_pages;
+ int ret;
+
+ new_array_pages = port / EVENT_WORDS_PER_PAGE + 1;
+
+ if (new_array_pages > MAX_EVENT_ARRAY_PAGES)
+ return -EINVAL;
+
+ while (event_array_pages < new_array_pages) {
+ void *array_page;
+ struct evtchn_expand_array expand_array;
+
+ /* Might already have a page if we've resumed. */
+ array_page = event_array[event_array_pages];
+ if (!array_page) {
+ array_page = (void *)__get_free_page(GFP_KERNEL);
+ if (array_page == NULL) {
+ ret = -ENOMEM;
+ goto error;
+ }
+ event_array[event_array_pages] = array_page;
+ }
+
+ /* Mask all events in this page before adding it. */
+ init_array_page(array_page);
+
+ expand_array.array_gfn = virt_to_gfn(array_page);
+
+ ret = HYPERVISOR_event_channel_op(EVTCHNOP_expand_array, &expand_array);
+ if (ret < 0)
+ goto error;
+
+ event_array_pages++;
+ }
+ return 0;
+
+ error:
+ if (event_array_pages == 0)
+ panic("xen: unable to expand event array with initial page (%d)\n", ret);
+ else
+ pr_err("unable to expand event array (%d)\n", ret);
+ free_unused_array_pages();
+ return ret;
+}
+
+static void evtchn_fifo_bind_to_cpu(evtchn_port_t evtchn, unsigned int cpu,
+ unsigned int old_cpu)
+{
+ /* no-op */
+}
+
+static void evtchn_fifo_clear_pending(evtchn_port_t port)
+{
+ event_word_t *word = event_word_from_port(port);
+ sync_clear_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
+}
+
+static void evtchn_fifo_set_pending(evtchn_port_t port)
+{
+ event_word_t *word = event_word_from_port(port);
+ sync_set_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
+}
+
+static bool evtchn_fifo_is_pending(evtchn_port_t port)
+{
+ event_word_t *word = event_word_from_port(port);
+ return sync_test_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word));
+}
+
+static void evtchn_fifo_mask(evtchn_port_t port)
+{
+ event_word_t *word = event_word_from_port(port);
+ sync_set_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
+}
+
+static bool evtchn_fifo_is_masked(evtchn_port_t port)
+{
+ event_word_t *word = event_word_from_port(port);
+ return sync_test_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word));
+}
+/*
+ * Clear MASKED if not PENDING, spinning if BUSY is set.
+ * Return true if mask was cleared.
+ */
+static bool clear_masked_cond(volatile event_word_t *word)
+{
+ event_word_t new, old, w;
+
+ w = *word;
+
+ do {
+ if (!(w & (1 << EVTCHN_FIFO_MASKED)))
+ return true;
+
+ if (w & (1 << EVTCHN_FIFO_PENDING))
+ return false;
+
+ old = w & ~(1 << EVTCHN_FIFO_BUSY);
+ new = old & ~(1 << EVTCHN_FIFO_MASKED);
+ w = sync_cmpxchg(word, old, new);
+ } while (w != old);
+
+ return true;
+}
+
+static void evtchn_fifo_unmask(evtchn_port_t port)
+{
+ event_word_t *word = event_word_from_port(port);
+
+ BUG_ON(!irqs_disabled());
+
+ if (!clear_masked_cond(word)) {
+ struct evtchn_unmask unmask = { .port = port };
+ (void)HYPERVISOR_event_channel_op(EVTCHNOP_unmask, &unmask);
+ }
+}
+
+static uint32_t clear_linked(volatile event_word_t *word)
+{
+ event_word_t new, old, w;
+
+ w = *word;
+
+ do {
+ old = w;
+ new = (w & ~((1 << EVTCHN_FIFO_LINKED)
+ | EVTCHN_FIFO_LINK_MASK));
+ } while ((w = sync_cmpxchg(word, old, new)) != old);
+
+ return w & EVTCHN_FIFO_LINK_MASK;
+}
+
+static void consume_one_event(unsigned cpu, struct evtchn_loop_ctrl *ctrl,
+ struct evtchn_fifo_control_block *control_block,
+ unsigned priority, unsigned long *ready)
+{
+ struct evtchn_fifo_queue *q = &per_cpu(cpu_queue, cpu);
+ uint32_t head;
+ evtchn_port_t port;
+ event_word_t *word;
+
+ head = q->head[priority];
+
+ /*
+ * Reached the tail last time? Read the new HEAD from the
+ * control block.
+ */
+ if (head == 0) {
+ virt_rmb(); /* Ensure word is up-to-date before reading head. */
+ head = control_block->head[priority];
+ }
+
+ port = head;
+ word = event_word_from_port(port);
+ head = clear_linked(word);
+
+ /*
+ * If the link is non-zero, there are more events in the
+ * queue, otherwise the queue is empty.
+ *
+ * If the queue is empty, clear this priority from our local
+ * copy of the ready word.
+ */
+ if (head == 0)
+ clear_bit(priority, ready);
+
+ if (evtchn_fifo_is_pending(port) && !evtchn_fifo_is_masked(port)) {
+ if (unlikely(!ctrl))
+ pr_warn("Dropping pending event for port %u\n", port);
+ else
+ handle_irq_for_port(port, ctrl);
+ }
+
+ q->head[priority] = head;
+}
+
+static void __evtchn_fifo_handle_events(unsigned cpu,
+ struct evtchn_loop_ctrl *ctrl)
+{
+ struct evtchn_fifo_control_block *control_block;
+ unsigned long ready;
+ unsigned q;
+
+ control_block = per_cpu(cpu_control_block, cpu);
+
+ ready = xchg(&control_block->ready, 0);
+
+ while (ready) {
+ q = find_first_bit(&ready, EVTCHN_FIFO_MAX_QUEUES);
+ consume_one_event(cpu, ctrl, control_block, q, &ready);
+ ready |= xchg(&control_block->ready, 0);
+ }
+}
+
+static void evtchn_fifo_handle_events(unsigned cpu,
+ struct evtchn_loop_ctrl *ctrl)
+{
+ __evtchn_fifo_handle_events(cpu, ctrl);
+}
+
+static void evtchn_fifo_resume(void)
+{
+ unsigned cpu;
+
+ for_each_possible_cpu(cpu) {
+ void *control_block = per_cpu(cpu_control_block, cpu);
+ int ret;
+
+ if (!control_block)
+ continue;
+
+ /*
+ * If this CPU is offline, take the opportunity to
+ * free the control block while it is not being
+ * used.
+ */
+ if (!cpu_online(cpu)) {
+ free_page((unsigned long)control_block);
+ per_cpu(cpu_control_block, cpu) = NULL;
+ continue;
+ }
+
+ ret = init_control_block(cpu, control_block);
+ BUG_ON(ret < 0);
+ }
+
+ /*
+ * The event array starts out as empty again and is extended
+ * as normal when events are bound. The existing pages will
+ * be reused.
+ */
+ event_array_pages = 0;
+}
+
+static int evtchn_fifo_alloc_control_block(unsigned cpu)
+{
+ void *control_block = NULL;
+ int ret = -ENOMEM;
+
+ control_block = (void *)__get_free_page(GFP_KERNEL);
+ if (control_block == NULL)
+ goto error;
+
+ ret = init_control_block(cpu, control_block);
+ if (ret < 0)
+ goto error;
+
+ per_cpu(cpu_control_block, cpu) = control_block;
+
+ return 0;
+
+ error:
+ free_page((unsigned long)control_block);
+ return ret;
+}
+
+static int evtchn_fifo_percpu_init(unsigned int cpu)
+{
+ if (!per_cpu(cpu_control_block, cpu))
+ return evtchn_fifo_alloc_control_block(cpu);
+ return 0;
+}
+
+static int evtchn_fifo_percpu_deinit(unsigned int cpu)
+{
+ __evtchn_fifo_handle_events(cpu, NULL);
+ return 0;
+}
+
+static const struct evtchn_ops evtchn_ops_fifo = {
+ .max_channels = evtchn_fifo_max_channels,
+ .nr_channels = evtchn_fifo_nr_channels,
+ .setup = evtchn_fifo_setup,
+ .bind_to_cpu = evtchn_fifo_bind_to_cpu,
+ .clear_pending = evtchn_fifo_clear_pending,
+ .set_pending = evtchn_fifo_set_pending,
+ .is_pending = evtchn_fifo_is_pending,
+ .mask = evtchn_fifo_mask,
+ .unmask = evtchn_fifo_unmask,
+ .handle_events = evtchn_fifo_handle_events,
+ .resume = evtchn_fifo_resume,
+ .percpu_init = evtchn_fifo_percpu_init,
+ .percpu_deinit = evtchn_fifo_percpu_deinit,
+};
+
+int __init xen_evtchn_fifo_init(void)
+{
+ int cpu = smp_processor_id();
+ int ret;
+
+ ret = evtchn_fifo_alloc_control_block(cpu);
+ if (ret < 0)
+ return ret;
+
+ pr_info("Using FIFO-based ABI\n");
+
+ evtchn_ops = &evtchn_ops_fifo;
+
+ return ret;
+}
diff --git a/drivers/xen/events/events_internal.h b/drivers/xen/events/events_internal.h
new file mode 100644
index 000000000..4d3398eff
--- /dev/null
+++ b/drivers/xen/events/events_internal.h
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Xen Event Channels (internal header)
+ *
+ * Copyright (C) 2013 Citrix Systems R&D Ltd.
+ */
+#ifndef __EVENTS_INTERNAL_H__
+#define __EVENTS_INTERNAL_H__
+
+struct evtchn_loop_ctrl;
+
+struct evtchn_ops {
+ unsigned (*max_channels)(void);
+ unsigned (*nr_channels)(void);
+
+ int (*setup)(evtchn_port_t port);
+ void (*remove)(evtchn_port_t port, unsigned int cpu);
+ void (*bind_to_cpu)(evtchn_port_t evtchn, unsigned int cpu,
+ unsigned int old_cpu);
+
+ void (*clear_pending)(evtchn_port_t port);
+ void (*set_pending)(evtchn_port_t port);
+ bool (*is_pending)(evtchn_port_t port);
+ void (*mask)(evtchn_port_t port);
+ void (*unmask)(evtchn_port_t port);
+
+ void (*handle_events)(unsigned cpu, struct evtchn_loop_ctrl *ctrl);
+ void (*resume)(void);
+
+ int (*percpu_init)(unsigned int cpu);
+ int (*percpu_deinit)(unsigned int cpu);
+};
+
+extern const struct evtchn_ops *evtchn_ops;
+
+int get_evtchn_to_irq(evtchn_port_t evtchn);
+void handle_irq_for_port(evtchn_port_t port, struct evtchn_loop_ctrl *ctrl);
+
+unsigned int cpu_from_evtchn(evtchn_port_t evtchn);
+
+static inline unsigned xen_evtchn_max_channels(void)
+{
+ return evtchn_ops->max_channels();
+}
+
+/*
+ * Do any ABI specific setup for a bound event channel before it can
+ * be unmasked and used.
+ */
+static inline int xen_evtchn_port_setup(evtchn_port_t evtchn)
+{
+ if (evtchn_ops->setup)
+ return evtchn_ops->setup(evtchn);
+ return 0;
+}
+
+static inline void xen_evtchn_port_remove(evtchn_port_t evtchn,
+ unsigned int cpu)
+{
+ if (evtchn_ops->remove)
+ evtchn_ops->remove(evtchn, cpu);
+}
+
+static inline void xen_evtchn_port_bind_to_cpu(evtchn_port_t evtchn,
+ unsigned int cpu,
+ unsigned int old_cpu)
+{
+ evtchn_ops->bind_to_cpu(evtchn, cpu, old_cpu);
+}
+
+static inline void clear_evtchn(evtchn_port_t port)
+{
+ evtchn_ops->clear_pending(port);
+}
+
+static inline void set_evtchn(evtchn_port_t port)
+{
+ evtchn_ops->set_pending(port);
+}
+
+static inline bool test_evtchn(evtchn_port_t port)
+{
+ return evtchn_ops->is_pending(port);
+}
+
+static inline void mask_evtchn(evtchn_port_t port)
+{
+ return evtchn_ops->mask(port);
+}
+
+static inline void unmask_evtchn(evtchn_port_t port)
+{
+ return evtchn_ops->unmask(port);
+}
+
+static inline void xen_evtchn_handle_events(unsigned cpu,
+ struct evtchn_loop_ctrl *ctrl)
+{
+ return evtchn_ops->handle_events(cpu, ctrl);
+}
+
+static inline void xen_evtchn_resume(void)
+{
+ if (evtchn_ops->resume)
+ evtchn_ops->resume();
+}
+
+void xen_evtchn_2l_init(void);
+int xen_evtchn_fifo_init(void);
+
+#endif /* #ifndef __EVENTS_INTERNAL_H__ */