This patch tries to use smaller locks for each irq in the ics, instead
of a lock at the ics level, to provide better scalability.
Signed-off-by: Li Zhong <zh...@linux.vnet.ibm.com>
---
arch/powerpc/kvm/book3s_hv_rm_xics.c | 24 ++++++++++-----------
arch/powerpc/kvm/book3s_xics.c | 41 +++++++++++++++++++-----------------
arch/powerpc/kvm/book3s_xics.h | 2 +-
3 files changed, 34 insertions(+), 33 deletions(-)
diff --git a/arch/powerpc/kvm/book3s_hv_rm_xics.c
b/arch/powerpc/kvm/book3s_hv_rm_xics.c
index 980d8a6..c3f604e 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_xics.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_xics.c
@@ -36,20 +36,19 @@ static void ics_rm_check_resend(struct kvmppc_xics *xics,
{
int i;
- arch_spin_lock(&ics->lock);
-
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
struct ics_irq_state *state = &ics->irq_state[i];
- if (!state->resend)
+ arch_spin_lock(&state->lock);
+
+ if (!state->resend) {
+ arch_spin_unlock(&state->lock);
continue;
+ }
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&state->lock);
icp_rm_deliver_irq(xics, icp, state->number);
- arch_spin_lock(&ics->lock);
}
-
- arch_spin_unlock(&ics->lock);
}
/* -- ICP routines -- */
@@ -310,8 +309,7 @@ static void icp_rm_deliver_irq(struct kvmppc_xics *xics,
struct kvmppc_icp *icp,
}
state = &ics->irq_state[src];
- /* Get a lock on the ICS */
- arch_spin_lock(&ics->lock);
+ arch_spin_lock(&state->lock);
/* Get our server */
if (!icp || state->server != icp->server_num) {
@@ -367,7 +365,7 @@ static void icp_rm_deliver_irq(struct kvmppc_xics *xics,
struct kvmppc_icp *icp,
* Delivery was successful, did we reject somebody else ?
*/
if (reject && reject != XICS_IPI) {
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&state->lock);
new_irq = reject;
goto again;
}
@@ -387,12 +385,12 @@ static void icp_rm_deliver_irq(struct kvmppc_xics *xics,
struct kvmppc_icp *icp,
*/
smp_mb();
if (!icp->state.need_resend) {
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&state->lock);
goto again;
}
}
- out:
- arch_spin_unlock(&ics->lock);
+out:
+ arch_spin_unlock(&state->lock);
}
static void icp_rm_down_cppr(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
diff --git a/arch/powerpc/kvm/book3s_xics.c b/arch/powerpc/kvm/book3s_xics.c
index 46871d5..b9dbf75 100644
--- a/arch/powerpc/kvm/book3s_xics.c
+++ b/arch/powerpc/kvm/book3s_xics.c
@@ -113,25 +113,26 @@ static void ics_check_resend(struct kvmppc_xics *xics,
struct kvmppc_ics *ics,
unsigned long flags;
local_irq_save(flags);
- arch_spin_lock(&ics->lock);
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
struct ics_irq_state *state = &ics->irq_state[i];
- if (!state->resend)
+ arch_spin_lock(&state->lock);
+
+ if (!state->resend) {
+ arch_spin_unlock(&state->lock);
continue;
+ }
XICS_DBG("resend %#x prio %#x\n", state->number,
state->priority);
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&state->lock);
local_irq_restore(flags);
icp_deliver_irq(xics, icp, state->number);
local_irq_save(flags);
- arch_spin_lock(&ics->lock);
}
- arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
}
@@ -143,7 +144,7 @@ static bool write_xive(struct kvmppc_xics *xics, struct
kvmppc_ics *ics,
unsigned long flags;
local_irq_save(flags);
- arch_spin_lock(&ics->lock);
+ arch_spin_lock(&state->lock);
state->server = server;
state->priority = priority;
@@ -154,7 +155,7 @@ static bool write_xive(struct kvmppc_xics *xics, struct
kvmppc_ics *ics,
deliver = true;
}
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&state->lock);
local_irq_restore(flags);
return deliver;
@@ -207,10 +208,10 @@ int kvmppc_xics_get_xive(struct kvm *kvm, u32 irq, u32
*server, u32 *priority)
state = &ics->irq_state[src];
local_irq_save(flags);
- arch_spin_lock(&ics->lock);
+ arch_spin_lock(&state->lock);
*server = state->server;
*priority = state->priority;
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&state->lock);
local_irq_restore(flags);
return 0;
@@ -406,7 +407,7 @@ static void icp_deliver_irq(struct kvmppc_xics *xics,
struct kvmppc_icp *icp,
/* Get a lock on the ICS */
local_irq_save(flags);
- arch_spin_lock(&ics->lock);
+ arch_spin_lock(&state->lock);
/* Get our server */
if (!icp || state->server != icp->server_num) {
@@ -463,7 +464,7 @@ static void icp_deliver_irq(struct kvmppc_xics *xics,
struct kvmppc_icp *icp,
* Delivery was successful, did we reject somebody else ?
*/
if (reject && reject != XICS_IPI) {
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&state->lock);
local_irq_restore(flags);
new_irq = reject;
goto again;
@@ -484,13 +485,13 @@ static void icp_deliver_irq(struct kvmppc_xics *xics,
struct kvmppc_icp *icp,
*/
smp_mb();
if (!icp->state.need_resend) {
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&state->lock);
local_irq_restore(flags);
goto again;
}
}
out:
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&state->lock);
local_irq_restore(flags);
}
@@ -950,18 +951,18 @@ static int xics_debug_show(struct seq_file *m, void
*private)
icsid);
local_irq_save(flags);
- arch_spin_lock(&ics->lock);
for (i = 0; i < KVMPPC_XICS_IRQ_PER_ICS; i++) {
struct ics_irq_state *irq = &ics->irq_state[i];
+ arch_spin_lock(&irq->lock);
seq_printf(m, "irq 0x%06x: server %#x prio %#x save
prio %#x asserted %d resend %d masked pending %d\n",
irq->number, irq->server, irq->priority,
irq->saved_priority, irq->asserted,
irq->resend, irq->masked_pending);
+ arch_spin_unlock(&irq->lock);
}
- arch_spin_unlock(&ics->lock);
local_irq_restore(flags);
}
return 0;
@@ -1021,6 +1022,8 @@ static struct kvmppc_ics *kvmppc_xics_create_ics(struct
kvm *kvm,
ics->irq_state[i].number = (icsid << KVMPPC_XICS_ICS_SHIFT) | i;
ics->irq_state[i].priority = MASKED;
ics->irq_state[i].saved_priority = MASKED;
+ ics->irq_state[i].lock =
+ (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
}
smp_wmb();
xics->ics[icsid] = ics;
@@ -1164,7 +1167,7 @@ static int xics_get_source(struct kvmppc_xics *xics, long
irq, u64 addr)
irqp = &ics->irq_state[idx];
local_irq_save(flags);
- arch_spin_lock(&ics->lock);
+ arch_spin_lock(&irqp->lock);
ret = -ENOENT;
if (irqp->exists) {
val = irqp->server;
@@ -1180,7 +1183,7 @@ static int xics_get_source(struct kvmppc_xics *xics, long
irq, u64 addr)
val |= KVM_XICS_PENDING;
ret = 0;
}
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&irqp->lock);
local_irq_restore(flags);
if (!ret && put_user(val, ubufp))
@@ -1220,7 +1223,7 @@ static int xics_set_source(struct kvmppc_xics *xics, long
irq, u64 addr)
return -EINVAL;
local_irq_save(flags);
- arch_spin_lock(&ics->lock);
+ arch_spin_lock(&irqp->lock);
irqp->server = server;
irqp->saved_priority = prio;
if (val & KVM_XICS_MASKED)
@@ -1232,7 +1235,7 @@ static int xics_set_source(struct kvmppc_xics *xics, long
irq, u64 addr)
if ((val & KVM_XICS_PENDING) && (val & KVM_XICS_LEVEL_SENSITIVE))
irqp->asserted = 1;
irqp->exists = 1;
- arch_spin_unlock(&ics->lock);
+ arch_spin_unlock(&irqp->lock);
local_irq_restore(flags);
if (val & KVM_XICS_PENDING)
diff --git a/arch/powerpc/kvm/book3s_xics.h b/arch/powerpc/kvm/book3s_xics.h
index 56ea44f..d30564b 100644
--- a/arch/powerpc/kvm/book3s_xics.h
+++ b/arch/powerpc/kvm/book3s_xics.h
@@ -33,6 +33,7 @@
/* State for one irq source */
struct ics_irq_state {
+ arch_spinlock_t lock;
u32 number;
u32 server;
u8 priority;
@@ -93,7 +94,6 @@ struct kvmppc_icp {
};
struct kvmppc_ics {
- arch_spinlock_t lock;
u16 icsid;
struct ics_irq_state irq_state[KVMPPC_XICS_IRQ_PER_ICS];
};
--
1.8.3.1
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