Mailing List Archive

[RFC PATCH 1/3] Xen: generalized event channel operations.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
---
drivers/xen/events.c | 110 ++++++++++++++++++++++++++++++++++----------------
1 file changed, 76 insertions(+), 34 deletions(-)

diff --git a/drivers/xen/events.c b/drivers/xen/events.c
index 7595581..835101f 100644
--- a/drivers/xen/events.c
+++ b/drivers/xen/events.c
@@ -51,6 +51,23 @@
#include <xen/interface/hvm/hvm_op.h>
#include <xen/interface/hvm/params.h>

+/* N-level event channel, starting from 2 */
+static unsigned int evtchn_level = 2;
+
+struct evtchn_ops {
+ unsigned long (*active_evtchns)(unsigned int,
+ struct shared_info*, unsigned int);
+ void (*clear_evtchn)(int);
+ void (*set_evtchn)(int);
+ int (*test_evtchn)(int);
+ void (*mask_evtchn)(int);
+ void (*unmask_evtchn)(int);
+ int (*is_masked)(int);
+ void (*xen_evtchn_do_upcall)(void);
+ irqreturn_t (*xen_debug_interrupt)(int, void*);
+};
+static struct evtchn_ops *eops;
+
/*
* 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.
@@ -285,9 +302,9 @@ static bool pirq_needs_eoi_flag(unsigned irq)
return info->u.pirq.flags & PIRQ_NEEDS_EOI;
}

-static inline unsigned long active_evtchns(unsigned int cpu,
- struct shared_info *sh,
- unsigned int idx)
+static inline unsigned long __active_evtchns_l2(unsigned int cpu,
+ struct shared_info *sh,
+ unsigned int idx)
{
return sh->evtchn_pending[idx] &
per_cpu(cpu_evtchn_mask, cpu)[idx] &
@@ -309,6 +326,7 @@ static void bind_evtchn_to_cpu(unsigned int chn, unsigned int cpu)
info_for_irq(irq)->cpu = cpu;
}

+
static void init_evtchn_cpu_bindings(void)
{
int i;
@@ -327,25 +345,24 @@ static void init_evtchn_cpu_bindings(void)
(i == 0) ? ~0 : 0, sizeof(*per_cpu(cpu_evtchn_mask, i)));
}

-static inline void clear_evtchn(int port)
+static inline void __clear_evtchn_l2(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
sync_clear_bit(port, &s->evtchn_pending[0]);
}

-static inline void set_evtchn(int port)
+static inline void __set_evtchn_l2(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
sync_set_bit(port, &s->evtchn_pending[0]);
}

-static inline int test_evtchn(int port)
+static inline int __test_evtchn_l2(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
return sync_test_bit(port, &s->evtchn_pending[0]);
}

-
/**
* notify_remote_via_irq - send event to remote end of event channel via irq
* @irq: irq of event channel to send event to
@@ -363,13 +380,13 @@ void notify_remote_via_irq(int irq)
}
EXPORT_SYMBOL_GPL(notify_remote_via_irq);

-static void mask_evtchn(int port)
+static void __mask_evtchn_l2(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
sync_set_bit(port, &s->evtchn_mask[0]);
}

-static void unmask_evtchn(int port)
+static void __unmask_evtchn_l2(int port)
{
struct shared_info *s = HYPERVISOR_shared_info;
unsigned int cpu = get_cpu();
@@ -521,7 +538,7 @@ static void eoi_pirq(struct irq_data *data)
irq_move_irq(data);

if (VALID_EVTCHN(evtchn))
- clear_evtchn(evtchn);
+ eops->clear_evtchn(evtchn);

if (pirq_needs_eoi(data->irq)) {
rc = HYPERVISOR_physdev_op(PHYSDEVOP_eoi, &eoi);
@@ -567,7 +584,7 @@ static unsigned int __startup_pirq(unsigned int irq)
info->evtchn = evtchn;

out:
- unmask_evtchn(evtchn);
+ eops->unmask_evtchn(evtchn);
eoi_pirq(irq_get_irq_data(irq));

return 0;
@@ -590,7 +607,7 @@ static void shutdown_pirq(struct irq_data *data)
if (!VALID_EVTCHN(evtchn))
return;

- mask_evtchn(evtchn);
+ eops->mask_evtchn(evtchn);

close.port = evtchn;
if (HYPERVISOR_event_channel_op(EVTCHNOP_close, &close) != 0)
@@ -1164,7 +1181,7 @@ void xen_send_IPI_one(unsigned int cpu, enum ipi_vector vector)
notify_remote_via_irq(irq);
}

-irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
+static irqreturn_t __xen_debug_interrupt_l2(int irq, void *dev_id)
{
struct shared_info *sh = HYPERVISOR_shared_info;
int cpu = smp_processor_id();
@@ -1245,6 +1262,11 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
return IRQ_HANDLED;
}

+irqreturn_t xen_debug_interrupt(int irq, void *dev_id)
+{
+ return eops->xen_debug_interrupt(irq, dev_id);
+}
+
static DEFINE_PER_CPU(unsigned, xed_nesting_count);
static DEFINE_PER_CPU(unsigned int, current_word_idx);
static DEFINE_PER_CPU(unsigned int, current_bit_idx);
@@ -1263,7 +1285,7 @@ static DEFINE_PER_CPU(unsigned int, current_bit_idx);
* a bitset of words which contain pending event bits. The second
* level is a bitset of pending events themselves.
*/
-static void __xen_evtchn_do_upcall(void)
+static void __xen_evtchn_do_upcall_l2(void)
{
int start_word_idx, start_bit_idx;
int word_idx, bit_idx;
@@ -1308,7 +1330,7 @@ static void __xen_evtchn_do_upcall(void)
}
word_idx = __ffs(words);

- pending_bits = active_evtchns(cpu, s, word_idx);
+ pending_bits = eops->active_evtchns(cpu, s, word_idx);
bit_idx = 0; /* usually scan entire word from start */
if (word_idx == start_word_idx) {
/* We scan the starting word in two parts */
@@ -1377,7 +1399,7 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)
exit_idle();
irq_enter();

- __xen_evtchn_do_upcall();
+ eops->xen_evtchn_do_upcall();

irq_exit();
set_irq_regs(old_regs);
@@ -1385,7 +1407,7 @@ void xen_evtchn_do_upcall(struct pt_regs *regs)

void xen_hvm_evtchn_do_upcall(void)
{
- __xen_evtchn_do_upcall();
+ eops->xen_evtchn_do_upcall();
}
EXPORT_SYMBOL_GPL(xen_hvm_evtchn_do_upcall);

@@ -1459,15 +1481,14 @@ static int set_affinity_irq(struct irq_data *data, const struct cpumask *dest,
int resend_irq_on_evtchn(unsigned int irq)
{
int masked, evtchn = evtchn_from_irq(irq);
- struct shared_info *s = HYPERVISOR_shared_info;

if (!VALID_EVTCHN(evtchn))
return 1;

- masked = sync_test_and_set_bit(evtchn, s->evtchn_mask);
- sync_set_bit(evtchn, s->evtchn_pending);
+ masked = eops->is_masked(evtchn);
+ eops->set_evtchn(evtchn);
if (!masked)
- unmask_evtchn(evtchn);
+ eops->unmask_evtchn(evtchn);

return 1;
}
@@ -1477,7 +1498,7 @@ static void enable_dynirq(struct irq_data *data)
int evtchn = evtchn_from_irq(data->irq);

if (VALID_EVTCHN(evtchn))
- unmask_evtchn(evtchn);
+ eops->unmask_evtchn(evtchn);
}

static void disable_dynirq(struct irq_data *data)
@@ -1485,7 +1506,7 @@ static void disable_dynirq(struct irq_data *data)
int evtchn = evtchn_from_irq(data->irq);

if (VALID_EVTCHN(evtchn))
- mask_evtchn(evtchn);
+ eops->mask_evtchn(evtchn);
}

static void ack_dynirq(struct irq_data *data)
@@ -1495,7 +1516,7 @@ static void ack_dynirq(struct irq_data *data)
irq_move_irq(data);

if (VALID_EVTCHN(evtchn))
- clear_evtchn(evtchn);
+ eops->clear_evtchn(evtchn);
}

static void mask_ack_dynirq(struct irq_data *data)
@@ -1504,19 +1525,24 @@ static void mask_ack_dynirq(struct irq_data *data)
ack_dynirq(data);
}

+static inline int __is_masked_l2(int chn)
+{
+ struct shared_info *sh = HYPERVISOR_shared_info;
+ return sync_test_and_set_bit(chn, sh->evtchn_mask);
+}
+
static int retrigger_dynirq(struct irq_data *data)
{
int evtchn = evtchn_from_irq(data->irq);
- struct shared_info *sh = HYPERVISOR_shared_info;
int ret = 0;

if (VALID_EVTCHN(evtchn)) {
int masked;

- masked = sync_test_and_set_bit(evtchn, sh->evtchn_mask);
- sync_set_bit(evtchn, sh->evtchn_pending);
+ masked = eops->is_masked(evtchn);
+ eops->set_evtchn(evtchn);
if (!masked)
- unmask_evtchn(evtchn);
+ eops->unmask_evtchn(evtchn);
ret = 1;
}

@@ -1616,7 +1642,7 @@ void xen_clear_irq_pending(int irq)
int evtchn = evtchn_from_irq(irq);

if (VALID_EVTCHN(evtchn))
- clear_evtchn(evtchn);
+ eops->clear_evtchn(evtchn);
}
EXPORT_SYMBOL(xen_clear_irq_pending);
void xen_set_irq_pending(int irq)
@@ -1624,7 +1650,7 @@ void xen_set_irq_pending(int irq)
int evtchn = evtchn_from_irq(irq);

if (VALID_EVTCHN(evtchn))
- set_evtchn(evtchn);
+ eops->set_evtchn(evtchn);
}

bool xen_test_irq_pending(int irq)
@@ -1633,7 +1659,7 @@ bool xen_test_irq_pending(int irq)
bool ret = false;

if (VALID_EVTCHN(evtchn))
- ret = test_evtchn(evtchn);
+ ret = eops->test_evtchn(evtchn);

return ret;
}
@@ -1684,7 +1710,7 @@ void xen_irq_resume(void)

/* New event-channel space is not 'live' yet. */
for (evtchn = 0; evtchn < NR_EVENT_CHANNELS; evtchn++)
- mask_evtchn(evtchn);
+ eops->mask_evtchn(evtchn);

/* No IRQ <-> event-channel mappings. */
list_for_each_entry(info, &xen_irq_list_head, list)
@@ -1783,12 +1809,28 @@ void xen_callback_vector(void)
void xen_callback_vector(void) {}
#endif

+static struct evtchn_ops evtchn_ops_l2 __read_mostly = {
+ .active_evtchns = __active_evtchns_l2,
+ .clear_evtchn = __clear_evtchn_l2,
+ .set_evtchn = __set_evtchn_l2,
+ .test_evtchn = __test_evtchn_l2,
+ .mask_evtchn = __mask_evtchn_l2,
+ .unmask_evtchn = __unmask_evtchn_l2,
+ .is_masked = __is_masked_l2,
+ .xen_evtchn_do_upcall = __xen_evtchn_do_upcall_l2,
+ .xen_debug_interrupt = __xen_debug_interrupt_l2,
+};
+
void __init xen_init_IRQ(void)
{
int i, rc;

+ evtchn_level = 2;
+ eops = &evtchn_ops_l2;
+
+ /* Setup 2-level event channel */
evtchn_to_irq = kcalloc(NR_EVENT_CHANNELS, sizeof(*evtchn_to_irq),
- GFP_KERNEL);
+ GFP_KERNEL);
BUG_ON(!evtchn_to_irq);
for (i = 0; i < NR_EVENT_CHANNELS; i++)
evtchn_to_irq[i] = -1;
@@ -1797,7 +1839,7 @@ void __init xen_init_IRQ(void)

/* No event channels are 'live' right now. */
for (i = 0; i < NR_EVENT_CHANNELS; i++)
- mask_evtchn(i);
+ eops->mask_evtchn(i);

pirq_needs_eoi = pirq_needs_eoi_flag;

--
1.7.10.4


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