diff options
Diffstat (limited to 'kernel/drivers/xen/events')
| -rw-r--r-- | kernel/drivers/xen/events/Makefile | 5 | ||||
| -rw-r--r-- | kernel/drivers/xen/events/events_2l.c | 375 | ||||
| -rw-r--r-- | kernel/drivers/xen/events/events_base.c | 1705 | ||||
| -rw-r--r-- | kernel/drivers/xen/events/events_fifo.c | 450 | ||||
| -rw-r--r-- | kernel/drivers/xen/events/events_internal.h | 151 |
5 files changed, 2686 insertions, 0 deletions
diff --git a/kernel/drivers/xen/events/Makefile b/kernel/drivers/xen/events/Makefile new file mode 100644 index 000000000..62be55cd9 --- /dev/null +++ b/kernel/drivers/xen/events/Makefile @@ -0,0 +1,5 @@ +obj-y += events.o + +events-y += events_base.o +events-y += events_2l.o +events-y += events_fifo.o diff --git a/kernel/drivers/xen/events/events_2l.c b/kernel/drivers/xen/events/events_2l.c new file mode 100644 index 000000000..7dd46312c --- /dev/null +++ b/kernel/drivers/xen/events/events_2l.c @@ -0,0 +1,375 @@ +/* + * 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 <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 [EVTCHN_2L_NR_CHANNELS/BITS_PER_EVTCHN_WORD], + cpu_evtchn_mask); + +static unsigned evtchn_2l_max_channels(void) +{ + return EVTCHN_2L_NR_CHANNELS; +} + +static void evtchn_2l_bind_to_cpu(struct irq_info *info, unsigned cpu) +{ + clear_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, info->cpu))); + set_bit(info->evtchn, BM(per_cpu(cpu_evtchn_mask, cpu))); +} + +static void evtchn_2l_clear_pending(unsigned port) +{ + struct shared_info *s = HYPERVISOR_shared_info; + sync_clear_bit(port, BM(&s->evtchn_pending[0])); +} + +static void evtchn_2l_set_pending(unsigned port) +{ + struct shared_info *s = HYPERVISOR_shared_info; + sync_set_bit(port, BM(&s->evtchn_pending[0])); +} + +static bool evtchn_2l_is_pending(unsigned port) +{ + struct shared_info *s = HYPERVISOR_shared_info; + return sync_test_bit(port, BM(&s->evtchn_pending[0])); +} + +static bool evtchn_2l_test_and_set_mask(unsigned port) +{ + struct shared_info *s = HYPERVISOR_shared_info; + return sync_test_and_set_bit(port, BM(&s->evtchn_mask[0])); +} + +static void evtchn_2l_mask(unsigned port) +{ + struct shared_info *s = HYPERVISOR_shared_info; + sync_set_bit(port, BM(&s->evtchn_mask[0])); +} + +static void evtchn_2l_unmask(unsigned 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 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) +{ + 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) { + unsigned int 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; + 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 = get_evtchn_to_irq(port); + + if (irq != -1) + generic_handle_irq(irq); + + 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 const struct evtchn_ops evtchn_ops_2l = { + .max_channels = evtchn_2l_max_channels, + .nr_channels = evtchn_2l_max_channels, + .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, + .test_and_set_mask = evtchn_2l_test_and_set_mask, + .mask = evtchn_2l_mask, + .unmask = evtchn_2l_unmask, + .handle_events = evtchn_2l_handle_events, + .resume = evtchn_2l_resume, +}; + +void __init xen_evtchn_2l_init(void) +{ + pr_info("Using 2-level ABI\n"); + evtchn_ops = &evtchn_ops_2l; +} diff --git a/kernel/drivers/xen/events/events_base.c b/kernel/drivers/xen/events/events_base.c new file mode 100644 index 000000000..383879504 --- /dev/null +++ b/kernel/drivers/xen/events/events_base.c @@ -0,0 +1,1705 @@ +/* + * 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/module.h> +#include <linux/string.h> +#include <linux/bootmem.h> +#include <linux/slab.h> +#include <linux/irqnr.h> +#include <linux/pci.h> + +#ifdef CONFIG_X86 +#include <asm/desc.h> +#include <asm/ptrace.h> +#include <asm/irq.h> +#include <asm/idle.h> +#include <asm/io_apic.h> +#include <asm/xen/page.h> +#include <asm/xen/pci.h> +#endif +#include <asm/sync_bitops.h> +#include <asm/xen/hypercall.h> +#include <asm/xen/hypervisor.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 <asm/hw_irq.h> + +#include "events_internal.h" + +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); + +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}; + +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_chip xen_dynamic_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 void clear_evtchn_to_irq_row(unsigned row) +{ + unsigned col; + + for (col = 0; col < EVTCHN_PER_ROW; col++) + evtchn_to_irq[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(row); + } +} + +static int set_evtchn_to_irq(unsigned evtchn, unsigned irq) +{ + unsigned row; + unsigned col; + + 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_to_irq[row] = (int *)get_zeroed_page(GFP_KERNEL); + if (evtchn_to_irq[row] == NULL) + return -ENOMEM; + + clear_evtchn_to_irq_row(row); + } + + evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)] = irq; + return 0; +} + +int get_evtchn_to_irq(unsigned evtchn) +{ + if (evtchn >= xen_evtchn_max_channels()) + return -1; + if (evtchn_to_irq[EVTCHN_ROW(evtchn)] == NULL) + return -1; + return evtchn_to_irq[EVTCHN_ROW(evtchn)][EVTCHN_COL(evtchn)]; +} + +/* Get info for IRQ */ +struct irq_info *info_for_irq(unsigned irq) +{ + return irq_get_handler_data(irq); +} + +/* Constructors for packed IRQ information. */ +static int xen_irq_info_common_setup(struct irq_info *info, + unsigned irq, + enum xen_irq_type type, + unsigned 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; + + 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(info); +} + +static int xen_irq_info_evtchn_setup(unsigned irq, + unsigned evtchn) +{ + struct irq_info *info = info_for_irq(irq); + + return xen_irq_info_common_setup(info, irq, IRQT_EVTCHN, evtchn, 0); +} + +static int xen_irq_info_ipi_setup(unsigned cpu, + unsigned irq, + unsigned 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, + unsigned 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, + unsigned 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); + info->evtchn = 0; +} + +/* + * Accessors for packed IRQ information. + */ +unsigned int evtchn_from_irq(unsigned irq) +{ + if (unlikely(WARN(irq >= nr_irqs, "Invalid irq %d!\n", irq))) + return 0; + + return info_for_irq(irq)->evtchn; +} + +unsigned irq_from_evtchn(unsigned int 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; +} + +unsigned cpu_from_irq(unsigned irq) +{ + return info_for_irq(irq)->cpu; +} + +unsigned int cpu_from_evtchn(unsigned int evtchn) +{ + int irq = get_evtchn_to_irq(evtchn); + unsigned ret = 0; + + if (irq != -1) + ret = cpu_from_irq(irq); + + return ret; +} + +#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(unsigned int chn, unsigned int cpu) +{ + int irq = get_evtchn_to_irq(chn); + struct irq_info *info = info_for_irq(irq); + + BUG_ON(irq == -1); +#ifdef CONFIG_SMP + cpumask_copy(irq_get_irq_data(irq)->affinity, cpumask_of(cpu)); +#endif + xen_evtchn_port_bind_to_cpu(info, cpu); + + info->cpu = cpu; +} + +static void xen_evtchn_mask_all(void) +{ + unsigned int evtchn; + + for (evtchn = 0; evtchn < xen_evtchn_nr_channels(); evtchn++) + mask_evtchn(evtchn); +} + +/** + * notify_remote_via_irq - send event to remote end of event channel via irq + * @irq: irq of event channel to send event to + * + * Unlike notify_remote_via_evtchn(), this is safe to use across + * save/restore. Notifications on a broken connection are silently + * dropped. + */ +void notify_remote_via_irq(int irq) +{ + int evtchn = evtchn_from_irq(irq); + + if (VALID_EVTCHN(evtchn)) + notify_remote_via_evtchn(evtchn); +} +EXPORT_SYMBOL_GPL(notify_remote_via_irq); + +static void xen_irq_init(unsigned irq) +{ + struct irq_info *info; +#ifdef CONFIG_SMP + /* By default all event channels notify CPU#0. */ + cpumask_copy(irq_get_irq_data(irq)->affinity, cpumask_of(0)); +#endif + + 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; + + irq_set_handler_data(irq, info); + + 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_IRQS_LEGACY) + 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 = irq_get_handler_data(irq); + + if (WARN_ON(!info)) + return; + + list_del(&info->list); + + irq_set_handler_data(irq, NULL); + + WARN_ON(info->refcnt > 0); + + kfree(info); + + /* Legacy IRQ descriptors are managed by the arch. */ + if (irq < NR_IRQS_LEGACY) + return; + + irq_free_desc(irq); +} + +static void xen_evtchn_close(unsigned int port) +{ + struct evtchn_close close; + + close.port = port; + if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0) + BUG(); +} + +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) +{ + int evtchn = evtchn_from_irq(data->irq); + struct physdev_eoi eoi = { .irq = pirq_from_irq(data->irq) }; + int rc = 0; + + irq_move_irq(data); + + if (VALID_EVTCHN(evtchn)) + clear_evtchn(evtchn); + + 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); + int 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); + + rc = xen_evtchn_port_setup(info); + if (rc) + goto err; + +out: + unmask_evtchn(evtchn); + 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); + unsigned evtchn = evtchn_from_irq(irq); + + BUG_ON(info->type != IRQT_PIRQ); + + if (!VALID_EVTCHN(evtchn)) + return; + + mask_evtchn(evtchn); + xen_evtchn_close(evtchn); + xen_irq_info_cleanup(info); +} + +static void enable_pirq(struct irq_data *data) +{ + startup_pirq(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) +{ + int evtchn = evtchn_from_irq(irq); + struct irq_info *info = irq_get_handler_data(irq); + + if (info->refcnt > 0) { + info->refcnt--; + if (info->refcnt != 0) + return; + } + + if (VALID_EVTCHN(evtchn)) { + unsigned int cpu = cpu_from_irq(irq); + + 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; + default: + break; + } + + xen_irq_info_cleanup(info); + } + + BUG_ON(info_for_irq(irq)->type == IRQT_UNBOUND); + + 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 = -1; + 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: + for (; i >= 0; i--) + __unbind_from_irq(irq + i); + 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); + +int bind_evtchn_to_irq(unsigned int evtchn) +{ + 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, &xen_dynamic_chip, + handle_edge_irq, "event"); + + ret = xen_irq_info_evtchn_setup(irq, evtchn); + if (ret < 0) { + __unbind_from_irq(irq); + irq = ret; + goto out; + } + /* New interdomain events are bound to VCPU 0. */ + bind_evtchn_to_cpu(evtchn, 0); + } 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; +} +EXPORT_SYMBOL_GPL(bind_evtchn_to_irq); + +static int bind_ipi_to_irq(unsigned int ipi, unsigned int cpu) +{ + struct evtchn_bind_ipi bind_ipi; + int evtchn, irq; + int ret; + + 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 = 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; + } + bind_evtchn_to_cpu(evtchn, cpu); + } 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; +} + +int bind_interdomain_evtchn_to_irq(unsigned int remote_domain, + unsigned int remote_port) +{ + struct evtchn_bind_interdomain bind_interdomain; + int err; + + bind_interdomain.remote_dom = remote_domain; + bind_interdomain.remote_port = remote_port; + + err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain, + &bind_interdomain); + + return err ? : bind_evtchn_to_irq(bind_interdomain.local_port); +} +EXPORT_SYMBOL_GPL(bind_interdomain_evtchn_to_irq); + +static int find_virq(unsigned int virq, unsigned int cpu) +{ + struct evtchn_status status; + int port, 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 == cpu) { + rc = 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; + int evtchn, 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 = 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); + BUG_ON(ret < 0); + evtchn = ret; + } + + ret = xen_irq_info_virq_setup(cpu, irq, evtchn, virq); + if (ret < 0) { + __unbind_from_irq(irq); + irq = ret; + goto out; + } + + bind_evtchn_to_cpu(evtchn, cpu); + } 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); +} + +int bind_evtchn_to_irqhandler(unsigned int evtchn, + irq_handler_t handler, + unsigned long irqflags, + const char *devname, void *dev_id) +{ + int irq, retval; + + irq = bind_evtchn_to_irq(evtchn); + 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_evtchn_to_irqhandler); + +int bind_interdomain_evtchn_to_irqhandler(unsigned int remote_domain, + unsigned int remote_port, + irq_handler_t handler, + unsigned long irqflags, + const char *devname, + void *dev_id) +{ + int irq, retval; + + irq = bind_interdomain_evtchn_to_irq(remote_domain, remote_port); + 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_interdomain_evtchn_to_irqhandler); + +int bind_virq_to_irqhandler(unsigned int virq, unsigned int cpu, + irq_handler_t handler, + unsigned long irqflags, const char *devname, void *dev_id) +{ + 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 = irq_get_handler_data(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(unsigned int evtchn) +{ + int irq = get_evtchn_to_irq(evtchn); + struct irq_info *info; + + if (irq == -1) + return -ENOENT; + + info = irq_get_handler_data(irq); + + if (!info) + return -ENOENT; + + WARN_ON(info->refcnt != -1); + + info->refcnt = 1; + + return 0; +} +EXPORT_SYMBOL_GPL(evtchn_make_refcounted); + +int evtchn_get(unsigned int 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 = irq_get_handler_data(irq); + + if (!info) + goto done; + + err = -EINVAL; + if (info->refcnt <= 0) + goto done; + + info->refcnt++; + err = 0; + done: + mutex_unlock(&irq_mapping_update_lock); + + return err; +} +EXPORT_SYMBOL_GPL(evtchn_get); + +void evtchn_put(unsigned int 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, 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); +} + +static DEFINE_PER_CPU(unsigned, xed_nesting_count); + +static void __xen_evtchn_do_upcall(void) +{ + struct vcpu_info *vcpu_info = __this_cpu_read(xen_vcpu); + int cpu = get_cpu(); + unsigned count; + + do { + vcpu_info->evtchn_upcall_pending = 0; + + if (__this_cpu_inc_return(xed_nesting_count) - 1) + goto out; + + xen_evtchn_handle_events(cpu); + + BUG_ON(!irqs_disabled()); + + count = __this_cpu_read(xed_nesting_count); + __this_cpu_write(xed_nesting_count, 0); + } while (count != 1 || vcpu_info->evtchn_upcall_pending); + +out: + + put_cpu(); +} + +void xen_evtchn_do_upcall(struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + + irq_enter(); +#ifdef CONFIG_X86 + exit_idle(); + inc_irq_stat(irq_hv_callback_count); +#endif + + __xen_evtchn_do_upcall(); + + irq_exit(); + set_irq_regs(old_regs); +} + +void xen_hvm_evtchn_do_upcall(void) +{ + __xen_evtchn_do_upcall(); +} +EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall); + +/* Rebind a new event channel to an existing irq. */ +void rebind_evtchn_irq(int 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); + + mutex_unlock(&irq_mapping_update_lock); + + bind_evtchn_to_cpu(evtchn, info->cpu); + /* This will be deferred until interrupt is processed */ + irq_set_affinity(irq, cpumask_of(info->cpu)); + + /* Unmask the event channel. */ + enable_irq(irq); +} + +/* Rebind an evtchn so that it gets delivered to a specific cpu */ +static int rebind_irq_to_cpu(unsigned irq, unsigned tcpu) +{ + struct evtchn_bind_vcpu bind_vcpu; + int evtchn = evtchn_from_irq(irq); + int masked; + + if (!VALID_EVTCHN(evtchn)) + return -1; + + /* + * Events delivered via platform PCI interrupts are always + * routed to vcpu 0 and hence cannot be rebound. + */ + if (xen_hvm_domain() && !xen_have_vector_callback) + return -1; + + /* Send future instances of this interrupt to other vcpu. */ + bind_vcpu.port = evtchn; + bind_vcpu.vcpu = tcpu; + + /* + * Mask the event while changing the VCPU binding to prevent + * it being delivered on an unexpected VCPU. + */ + masked = test_and_set_mask(evtchn); + + /* + * 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); + + if (!masked) + unmask_evtchn(evtchn); + + return 0; +} + +static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest, + bool force) +{ + unsigned tcpu = cpumask_first_and(dest, cpu_online_mask); + + return rebind_irq_to_cpu(data->irq, tcpu); +} + +static void enable_dynirq(struct irq_data *data) +{ + int evtchn = evtchn_from_irq(data->irq); + + if (VALID_EVTCHN(evtchn)) + unmask_evtchn(evtchn); +} + +static void disable_dynirq(struct irq_data *data) +{ + int evtchn = evtchn_from_irq(data->irq); + + if (VALID_EVTCHN(evtchn)) + mask_evtchn(evtchn); +} + +static void ack_dynirq(struct irq_data *data) +{ + int evtchn = evtchn_from_irq(data->irq); + + irq_move_irq(data); + + if (VALID_EVTCHN(evtchn)) + clear_evtchn(evtchn); +} + +static void mask_ack_dynirq(struct irq_data *data) +{ + disable_dynirq(data); + ack_dynirq(data); +} + +static int retrigger_dynirq(struct irq_data *data) +{ + unsigned int evtchn = evtchn_from_irq(data->irq); + int masked; + + if (!VALID_EVTCHN(evtchn)) + return 0; + + masked = test_and_set_mask(evtchn); + set_evtchn(evtchn); + if (!masked) + unmask_evtchn(evtchn); + + 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; + int virq, irq, evtchn; + + 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 = 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); + bind_evtchn_to_cpu(evtchn, cpu); + } +} + +static void restore_cpu_ipis(unsigned int cpu) +{ + struct evtchn_bind_ipi bind_ipi; + int ipi, irq, evtchn; + + 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 = 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); + bind_evtchn_to_cpu(evtchn, cpu); + } +} + +/* Clear an irq's pending state, in preparation for polling on it */ +void xen_clear_irq_pending(int irq) +{ + int evtchn = evtchn_from_irq(irq); + + if (VALID_EVTCHN(evtchn)) + clear_evtchn(evtchn); +} +EXPORT_SYMBOL(xen_clear_irq_pending); +void xen_set_irq_pending(int irq) +{ + int evtchn = evtchn_from_irq(irq); + + if (VALID_EVTCHN(evtchn)) + set_evtchn(evtchn); +} + +bool xen_test_irq_pending(int irq) +{ + int 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_mask_all(); + xen_evtchn_resume(); + + /* No IRQ <-> event-channel mappings. */ + list_for_each_entry(info, &xen_irq_list_head, list) + info->evtchn = 0; /* zap event-channel binding */ + + 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_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, +}; + +int xen_set_callback_via(uint64_t via) +{ + struct xen_hvm_param a; + a.domid = DOMID_SELF; + a.index = HVM_PARAM_CALLBACK_IRQ; + a.value = via; + return HYPERVISOR_hvm_op(HVMOP_set_param, &a); +} +EXPORT_SYMBOL_GPL(xen_set_callback_via); + +#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_callback_vector(void) +{ + int rc; + uint64_t callback_via; + if (xen_have_vector_callback) { + callback_via = HVM_CALLBACK_VECTOR(HYPERVISOR_CALLBACK_VECTOR); + rc = xen_set_callback_via(callback_via); + if (rc) { + pr_err("Request for Xen HVM callback vector failed\n"); + xen_have_vector_callback = 0; + return; + } + pr_info("Xen HVM callback vector for event delivery is enabled\n"); + /* in the restore case the vector has already been allocated */ + if (!test_bit(HYPERVISOR_CALLBACK_VECTOR, used_vectors)) + alloc_intr_gate(HYPERVISOR_CALLBACK_VECTOR, + xen_hvm_callback_vector); + } +} +#else +void xen_callback_vector(void) {} +#endif + +#undef MODULE_PARAM_PREFIX +#define MODULE_PARAM_PREFIX "xen." + +static bool fifo_events = true; +module_param(fifo_events, bool, 0); + +void __init xen_init_IRQ(void) +{ + int ret = -EINVAL; + + if (fifo_events) + ret = xen_evtchn_fifo_init(); + if (ret < 0) + xen_evtchn_2l_init(); + + 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. */ + xen_evtchn_mask_all(); + + pirq_needs_eoi = pirq_needs_eoi_flag; + +#ifdef CONFIG_X86 + if (xen_pv_domain()) { + irq_ctx_init(smp_processor_id()); + if (xen_initial_domain()) + pci_xen_initial_domain(); + } + if (xen_feature(XENFEAT_hvm_callback_vector)) + xen_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_mfn(pirq_eoi_map); + rc = HYPERVISOR_physdev_op(PHYSDEVOP_pirq_eoi_gmfn_v2, &eoi_gmfn); + /* TODO: No PVH support for PIRQ EOI */ + 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/kernel/drivers/xen/events/events_fifo.c b/kernel/drivers/xen/events/events_fifo.c new file mode 100644 index 000000000..417415d73 --- /dev/null +++ b/kernel/drivers/xen/events/events_fifo.c @@ -0,0 +1,450 @@ +/* + * 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/module.h> +#include <linux/smp.h> +#include <linux/percpu.h> +#include <linux/cpu.h> + +#include <asm/sync_bitops.h> +#include <asm/xen/hypercall.h> +#include <asm/xen/hypervisor.h> +#include <asm/xen/page.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" + +#define EVENT_WORDS_PER_PAGE (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(unsigned 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_mfn(control_block); + init_control.offset = 0; + init_control.vcpu = 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(struct irq_info *info) +{ + unsigned port = info->evtchn; + 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_mfn(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(struct irq_info *info, unsigned cpu) +{ + /* no-op */ +} + +static void evtchn_fifo_clear_pending(unsigned 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(unsigned 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(unsigned port) +{ + event_word_t *word = event_word_from_port(port); + return sync_test_bit(EVTCHN_FIFO_BIT(PENDING, word), BM(word)); +} + +static bool evtchn_fifo_test_and_set_mask(unsigned port) +{ + event_word_t *word = event_word_from_port(port); + return sync_test_and_set_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word)); +} + +static void evtchn_fifo_mask(unsigned 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(unsigned port) +{ + event_word_t *word = event_word_from_port(port); + return sync_test_bit(EVTCHN_FIFO_BIT(MASKED, word), BM(word)); +} +/* + * Clear MASKED, spinning if BUSY is set. + */ +static void clear_masked(volatile event_word_t *word) +{ + event_word_t new, old, w; + + w = *word; + + do { + old = w & ~(1 << EVTCHN_FIFO_BUSY); + new = old & ~(1 << EVTCHN_FIFO_MASKED); + w = sync_cmpxchg(word, old, new); + } while (w != old); +} + +static void evtchn_fifo_unmask(unsigned port) +{ + event_word_t *word = event_word_from_port(port); + + BUG_ON(!irqs_disabled()); + + clear_masked(word); + if (evtchn_fifo_is_pending(port)) { + 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 handle_irq_for_port(unsigned port) +{ + int irq; + + irq = get_evtchn_to_irq(port); + if (irq != -1) + generic_handle_irq(irq); +} + +static void consume_one_event(unsigned cpu, + 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; + unsigned 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) { + 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)) + handle_irq_for_port(port); + + q->head[priority] = head; +} + +static void evtchn_fifo_handle_events(unsigned cpu) +{ + 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, control_block, q, &ready); + ready |= xchg(&control_block->ready, 0); + } +} + +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); + if (ret < 0) + BUG(); + } + + /* + * 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 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, + .test_and_set_mask = evtchn_fifo_test_and_set_mask, + .mask = evtchn_fifo_mask, + .unmask = evtchn_fifo_unmask, + .handle_events = evtchn_fifo_handle_events, + .resume = evtchn_fifo_resume, +}; + +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_cpu_notification(struct notifier_block *self, + unsigned long action, + void *hcpu) +{ + int cpu = (long)hcpu; + int ret = 0; + + switch (action) { + case CPU_UP_PREPARE: + if (!per_cpu(cpu_control_block, cpu)) + ret = evtchn_fifo_alloc_control_block(cpu); + break; + default: + break; + } + return ret < 0 ? NOTIFY_BAD : NOTIFY_OK; +} + +static struct notifier_block evtchn_fifo_cpu_notifier = { + .notifier_call = evtchn_fifo_cpu_notification, +}; + +int __init xen_evtchn_fifo_init(void) +{ + int cpu = get_cpu(); + int ret; + + ret = evtchn_fifo_alloc_control_block(cpu); + if (ret < 0) + goto out; + + pr_info("Using FIFO-based ABI\n"); + + evtchn_ops = &evtchn_ops_fifo; + + register_cpu_notifier(&evtchn_fifo_cpu_notifier); +out: + put_cpu(); + return ret; +} diff --git a/kernel/drivers/xen/events/events_internal.h b/kernel/drivers/xen/events/events_internal.h new file mode 100644 index 000000000..50c2050a1 --- /dev/null +++ b/kernel/drivers/xen/events/events_internal.h @@ -0,0 +1,151 @@ +/* + * 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 int 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) +#define PIRQ_MSI_GROUP (1 << 2) + +struct evtchn_ops { + unsigned (*max_channels)(void); + unsigned (*nr_channels)(void); + + int (*setup)(struct irq_info *info); + void (*bind_to_cpu)(struct irq_info *info, unsigned cpu); + + void (*clear_pending)(unsigned port); + void (*set_pending)(unsigned port); + bool (*is_pending)(unsigned port); + bool (*test_and_set_mask)(unsigned port); + void (*mask)(unsigned port); + void (*unmask)(unsigned port); + + void (*handle_events)(unsigned cpu); + void (*resume)(void); +}; + +extern const struct evtchn_ops *evtchn_ops; + +extern int **evtchn_to_irq; +int get_evtchn_to_irq(unsigned int evtchn); + +struct irq_info *info_for_irq(unsigned irq); +unsigned cpu_from_irq(unsigned irq); +unsigned cpu_from_evtchn(unsigned int 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(struct irq_info *info) +{ + if (evtchn_ops->setup) + return evtchn_ops->setup(info); + return 0; +} + +static inline void xen_evtchn_port_bind_to_cpu(struct irq_info *info, + unsigned cpu) +{ + evtchn_ops->bind_to_cpu(info, cpu); +} + +static inline void clear_evtchn(unsigned port) +{ + evtchn_ops->clear_pending(port); +} + +static inline void set_evtchn(unsigned port) +{ + evtchn_ops->set_pending(port); +} + +static inline bool test_evtchn(unsigned port) +{ + return evtchn_ops->is_pending(port); +} + +static inline bool test_and_set_mask(unsigned port) +{ + return evtchn_ops->test_and_set_mask(port); +} + +static inline void mask_evtchn(unsigned port) +{ + return evtchn_ops->mask(port); +} + +static inline void unmask_evtchn(unsigned port) +{ + return evtchn_ops->unmask(port); +} + +static inline void xen_evtchn_handle_events(unsigned cpu) +{ + return evtchn_ops->handle_events(cpu); +} + +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__ */ |