''unsigned int'' is better suited as an array index on x86-64.
''u32'' produces better code than ''unsigned
long'' on x86-64, so use the
former for storing 32-bit values read from the hardware.
this_cpu() uses an implicit smp_processor_id(), and hence using
per_cpu() when the result of smp_processor_id() is already available
is more efficient.
Fold one case of cpu_isset()+cpu_clear() into cpu_test_and_clear().
Drop the unused return value of evt_do_broadcast().
Signed-off-by: Jan Beulich <jbeulich@novell.com>
--- 2011-03-09.orig/xen/arch/x86/hpet.c
+++ 2011-03-09/xen/arch/x86/hpet.c
@@ -50,7 +50,7 @@ struct hpet_event_channel
void (*event_handler)(struct hpet_event_channel *);
unsigned int idx; /* physical channel idx */
- int cpu; /* msi target */
+ unsigned int cpu; /* msi target */
int irq; /* msi irq */
unsigned int flags; /* HPET_EVT_x */
} __cacheline_aligned;
@@ -61,7 +61,7 @@ static unsigned int __read_mostly num_hp
DEFINE_PER_CPU(struct hpet_event_channel *, cpu_bc_channel);
-static int *__read_mostly irq_channel;
+static unsigned int *__read_mostly irq_channel;
#define irq_to_channel(irq) irq_channel[irq]
unsigned long __read_mostly hpet_address;
@@ -166,32 +166,24 @@ static int reprogram_hpet_evt_channel(
return ret;
}
-static int evt_do_broadcast(cpumask_t mask)
+static void evt_do_broadcast(cpumask_t mask)
{
- int ret = 0, cpu = smp_processor_id();
+ unsigned int cpu = smp_processor_id();
- if ( cpu_isset(cpu, mask) )
- {
- cpu_clear(cpu, mask);
+ if ( cpu_test_and_clear(cpu, mask) )
raise_softirq(TIMER_SOFTIRQ);
- ret = 1;
- }
cpuidle_wakeup_mwait(&mask);
if ( !cpus_empty(mask) )
- {
cpumask_raise_softirq(mask, TIMER_SOFTIRQ);
- ret = 1;
- }
- return ret;
}
static void handle_hpet_broadcast(struct hpet_event_channel *ch)
{
cpumask_t mask;
s_time_t now, next_event;
- int cpu;
+ unsigned int cpu;
spin_lock_irq(&ch->lock);
@@ -253,12 +245,11 @@ static void hpet_interrupt_handler(int i
static void hpet_msi_unmask(unsigned int irq)
{
- unsigned long cfg;
- int ch_idx = irq_to_channel(irq);
- struct hpet_event_channel *ch;
+ u32 cfg;
+ unsigned int ch_idx = irq_to_channel(irq);
+ struct hpet_event_channel *ch = hpet_events + ch_idx;
- BUG_ON(ch_idx < 0);
- ch = &hpet_events[ch_idx];
+ BUG_ON(ch_idx >= num_hpets_used);
cfg = hpet_read32(HPET_Tn_CFG(ch->idx));
cfg |= HPET_TN_FSB;
@@ -267,12 +258,11 @@ static void hpet_msi_unmask(unsigned int
static void hpet_msi_mask(unsigned int irq)
{
- unsigned long cfg;
- int ch_idx = irq_to_channel(irq);
- struct hpet_event_channel *ch;
+ u32 cfg;
+ unsigned int ch_idx = irq_to_channel(irq);
+ struct hpet_event_channel *ch = hpet_events + ch_idx;
- BUG_ON(ch_idx < 0);
- ch = &hpet_events[ch_idx];
+ BUG_ON(ch_idx >= num_hpets_used);
cfg = hpet_read32(HPET_Tn_CFG(ch->idx));
cfg &= ~HPET_TN_FSB;
@@ -281,11 +271,10 @@ static void hpet_msi_mask(unsigned int i
static void hpet_msi_write(unsigned int irq, struct msi_msg *msg)
{
- int ch_idx = irq_to_channel(irq);
- struct hpet_event_channel *ch;
+ unsigned int ch_idx = irq_to_channel(irq);
+ struct hpet_event_channel *ch = hpet_events + ch_idx;
- BUG_ON(ch_idx < 0);
- ch = &hpet_events[ch_idx];
+ BUG_ON(ch_idx >= num_hpets_used);
hpet_write32(msg->data, HPET_Tn_ROUTE(ch->idx));
hpet_write32(msg->address_lo, HPET_Tn_ROUTE(ch->idx) + 4);
@@ -293,11 +282,10 @@ static void hpet_msi_write(unsigned int
static void hpet_msi_read(unsigned int irq, struct msi_msg *msg)
{
- int ch_idx = irq_to_channel(irq);
- struct hpet_event_channel *ch;
+ unsigned int ch_idx = irq_to_channel(irq);
+ struct hpet_event_channel *ch = hpet_events + ch_idx;
- BUG_ON(ch_idx < 0);
- ch = &hpet_events[ch_idx];
+ BUG_ON(ch_idx >= num_hpets_used);
msg->data = hpet_read32(HPET_Tn_ROUTE(ch->idx));
msg->address_lo = hpet_read32(HPET_Tn_ROUTE(ch->idx) + 4);
@@ -404,11 +392,10 @@ static int __init hpet_assign_irq(unsign
return irq;
}
-static int __init hpet_fsb_cap_lookup(void)
+static unsigned int __init hpet_fsb_cap_lookup(void)
{
- unsigned int id;
- unsigned int num_chs, num_chs_used;
- int i;
+ u32 id;
+ unsigned int i, num_chs, num_chs_used;
/* TODO. */
if ( iommu_intremap )
@@ -432,7 +419,7 @@ static int __init hpet_fsb_cap_lookup(vo
for ( i = 0; i < num_chs; i++ )
{
struct hpet_event_channel *ch = &hpet_events[num_chs_used];
- unsigned long cfg = hpet_read32(HPET_Tn_CFG(i));
+ u32 cfg = hpet_read32(HPET_Tn_CFG(i));
/* Only consider HPET timer with MSI support */
if ( !(cfg & HPET_TN_FSB_CAP) )
@@ -447,20 +434,17 @@ static int __init hpet_fsb_cap_lookup(vo
num_chs_used++;
}
- printk(XENLOG_INFO
- "HPET: %d timers in total, %d timers will be used for
broadcast\n",
+ printk(XENLOG_INFO "HPET: %u timers (%u will be used for
broadcast)\n",
num_chs, num_chs_used);
return num_chs_used;
}
-static int next_channel;
-static spinlock_t next_lock = SPIN_LOCK_UNLOCKED;
-
-static struct hpet_event_channel *hpet_get_channel(int cpu)
+static struct hpet_event_channel *hpet_get_channel(unsigned int cpu)
{
- int i;
- int next;
+ static unsigned int next_channel;
+ static spinlock_t next_lock = SPIN_LOCK_UNLOCKED;
+ unsigned int i, next;
struct hpet_event_channel *ch;
if ( num_hpets_used == 0 )
@@ -489,7 +473,8 @@ static struct hpet_event_channel *hpet_g
return ch;
}
-static void hpet_attach_channel(int cpu, struct hpet_event_channel *ch)
+static void hpet_attach_channel(unsigned int cpu,
+ struct hpet_event_channel *ch)
{
ASSERT(spin_is_locked(&ch->lock));
@@ -507,7 +492,8 @@ static void hpet_attach_channel(int cpu,
set_affinity(ch->irq, cpumask_of_cpu(ch->cpu));
}
-static void hpet_detach_channel(int cpu, struct hpet_event_channel *ch)
+static void hpet_detach_channel(unsigned int cpu,
+ struct hpet_event_channel *ch)
{
ASSERT(spin_is_locked(&ch->lock));
ASSERT(ch == per_cpu(cpu_bc_channel, cpu));
@@ -564,7 +550,7 @@ void __init hpet_broadcast_init(void)
if ( hpet_rate == 0 )
return;
- irq_channel = xmalloc_array(int, nr_irqs);
+ irq_channel = xmalloc_array(unsigned int, nr_irqs);
BUG_ON(irq_channel == NULL);
for ( i = 0; i < nr_irqs; i++ )
irq_channel[i] = -1;
@@ -703,10 +689,10 @@ void hpet_disable_legacy_broadcast(void)
void hpet_broadcast_enter(void)
{
- int cpu = smp_processor_id();
+ unsigned int cpu = smp_processor_id();
struct hpet_event_channel *ch = per_cpu(cpu_bc_channel, cpu);
- if ( this_cpu(timer_deadline) == 0 )
+ if ( per_cpu(timer_deadline, cpu) == 0 )
return;
if ( !ch )
@@ -727,17 +713,17 @@ void hpet_broadcast_enter(void)
spin_lock(&ch->lock);
/* reprogram if current cpu expire time is nearer */
- if ( this_cpu(timer_deadline) < ch->next_event )
- reprogram_hpet_evt_channel(ch, this_cpu(timer_deadline), NOW(), 1);
+ if ( per_cpu(timer_deadline, cpu) < ch->next_event )
+ reprogram_hpet_evt_channel(ch, per_cpu(timer_deadline, cpu), NOW(), 1);
spin_unlock(&ch->lock);
}
void hpet_broadcast_exit(void)
{
- int cpu = smp_processor_id();
+ unsigned int cpu = smp_processor_id();
struct hpet_event_channel *ch = per_cpu(cpu_bc_channel, cpu);
- if ( this_cpu(timer_deadline) == 0 )
+ if ( per_cpu(timer_deadline, cpu) == 0 )
return;
if ( !ch )
@@ -745,7 +731,7 @@ void hpet_broadcast_exit(void)
/* Reprogram the deadline; trigger timer work now if it has passed. */
enable_APIC_timer();
- if ( !reprogram_timer(this_cpu(timer_deadline)) )
+ if ( !reprogram_timer(per_cpu(timer_deadline, cpu)) )
raise_softirq(TIMER_SOFTIRQ);
read_lock_irq(&ch->cpumask_lock);
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel