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Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_rm_xics.c')
-rw-r--r--arch/powerpc/kvm/book3s_hv_rm_xics.c138
1 files changed, 91 insertions, 47 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_rm_xics.c b/arch/powerpc/kvm/book3s_hv_rm_xics.c
index 29f43ed6d5eb..e78542d99cd6 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_xics.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_xics.c
@@ -35,7 +35,7 @@ int kvm_irq_bypass = 1;
EXPORT_SYMBOL(kvm_irq_bypass);
static void icp_rm_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
- u32 new_irq);
+ u32 new_irq, bool check_resend);
static int xics_opal_set_server(unsigned int hw_irq, int server_cpu);
/* -- ICS routines -- */
@@ -44,20 +44,12 @@ 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)
- continue;
-
- arch_spin_unlock(&ics->lock);
- icp_rm_deliver_irq(xics, icp, state->number);
- arch_spin_lock(&ics->lock);
+ if (state->resend)
+ icp_rm_deliver_irq(xics, icp, state->number, true);
}
- arch_spin_unlock(&ics->lock);
}
/* -- ICP routines -- */
@@ -288,7 +280,7 @@ static bool icp_rm_try_to_deliver(struct kvmppc_icp *icp, u32 irq, u8 priority,
}
static void icp_rm_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
- u32 new_irq)
+ u32 new_irq, bool check_resend)
{
struct ics_irq_state *state;
struct kvmppc_ics *ics;
@@ -333,6 +325,10 @@ static void icp_rm_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
}
}
+ if (check_resend)
+ if (!state->resend)
+ goto out;
+
/* Clear the resend bit of that interrupt */
state->resend = 0;
@@ -378,7 +374,9 @@ static void icp_rm_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
*/
if (reject && reject != XICS_IPI) {
arch_spin_unlock(&ics->lock);
+ icp->n_reject++;
new_irq = reject;
+ check_resend = 0;
goto again;
}
} else {
@@ -386,10 +384,16 @@ static void icp_rm_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
* We failed to deliver the interrupt we need to set the
* resend map bit and mark the ICS state as needing a resend
*/
- set_bit(ics->icsid, icp->resend_map);
state->resend = 1;
/*
+ * Make sure when checking resend, we don't miss the resend
+ * if resend_map bit is seen and cleared.
+ */
+ smp_wmb();
+ set_bit(ics->icsid, icp->resend_map);
+
+ /*
* If the need_resend flag got cleared in the ICP some time
* between icp_rm_try_to_deliver() atomic update and now, then
* we know it might have missed the resend_map bit. So we
@@ -397,7 +401,9 @@ static void icp_rm_deliver_irq(struct kvmppc_xics *xics, struct kvmppc_icp *icp,
*/
smp_mb();
if (!icp->state.need_resend) {
+ state->resend = 0;
arch_spin_unlock(&ics->lock);
+ check_resend = 0;
goto again;
}
}
@@ -592,7 +598,7 @@ int kvmppc_rm_h_ipi(struct kvm_vcpu *vcpu, unsigned long server,
/* Handle reject in real mode */
if (reject && reject != XICS_IPI) {
this_icp->n_reject++;
- icp_rm_deliver_irq(xics, icp, reject);
+ icp_rm_deliver_irq(xics, icp, reject, false);
}
/* Handle resends in real mode */
@@ -660,59 +666,45 @@ int kvmppc_rm_h_cppr(struct kvm_vcpu *vcpu, unsigned long cppr)
*/
if (reject && reject != XICS_IPI) {
icp->n_reject++;
- icp_rm_deliver_irq(xics, icp, reject);
+ icp_rm_deliver_irq(xics, icp, reject, false);
}
bail:
return check_too_hard(xics, icp);
}
-int kvmppc_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
+static int ics_rm_eoi(struct kvm_vcpu *vcpu, u32 irq)
{
struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
struct kvmppc_icp *icp = vcpu->arch.icp;
struct kvmppc_ics *ics;
struct ics_irq_state *state;
- u32 irq = xirr & 0x00ffffff;
u16 src;
-
- if (!xics || !xics->real_mode)
- return H_TOO_HARD;
+ u32 pq_old, pq_new;
/*
- * ICP State: EOI
+ * ICS EOI handling: For LSI, if P bit is still set, we need to
+ * resend it.
*
- * Note: If EOI is incorrectly used by SW to lower the CPPR
- * value (ie more favored), we do not check for rejection of
- * a pending interrupt, this is a SW error and PAPR sepcifies
- * that we don't have to deal with it.
- *
- * The sending of an EOI to the ICS is handled after the
- * CPPR update
- *
- * ICP State: Down_CPPR which we handle
- * in a separate function as it's shared with H_CPPR.
+ * For MSI, we move Q bit into P (and clear Q). If it is set,
+ * resend it.
*/
- icp_rm_down_cppr(xics, icp, xirr >> 24);
- /* IPIs have no EOI */
- if (irq == XICS_IPI)
- goto bail;
- /*
- * EOI handling: If the interrupt is still asserted, we need to
- * resend it. We can take a lockless "peek" at the ICS state here.
- *
- * "Message" interrupts will never have "asserted" set
- */
ics = kvmppc_xics_find_ics(xics, irq, &src);
if (!ics)
goto bail;
+
state = &ics->irq_state[src];
- /* Still asserted, resend it */
- if (state->asserted) {
- icp->n_reject++;
- icp_rm_deliver_irq(xics, icp, irq);
- }
+ if (state->lsi)
+ pq_new = state->pq_state;
+ else
+ do {
+ pq_old = state->pq_state;
+ pq_new = pq_old >> 1;
+ } while (cmpxchg(&state->pq_state, pq_old, pq_new) != pq_old);
+
+ if (pq_new & PQ_PRESENTED)
+ icp_rm_deliver_irq(xics, NULL, irq, false);
if (!hlist_empty(&vcpu->kvm->irq_ack_notifier_list)) {
icp->rm_action |= XICS_RM_NOTIFY_EOI;
@@ -733,10 +725,43 @@ int kvmppc_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
state->intr_cpu = -1;
}
}
+
bail:
return check_too_hard(xics, icp);
}
+int kvmppc_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
+{
+ struct kvmppc_xics *xics = vcpu->kvm->arch.xics;
+ struct kvmppc_icp *icp = vcpu->arch.icp;
+ u32 irq = xirr & 0x00ffffff;
+
+ if (!xics || !xics->real_mode)
+ return H_TOO_HARD;
+
+ /*
+ * ICP State: EOI
+ *
+ * Note: If EOI is incorrectly used by SW to lower the CPPR
+ * value (ie more favored), we do not check for rejection of
+ * a pending interrupt, this is a SW error and PAPR specifies
+ * that we don't have to deal with it.
+ *
+ * The sending of an EOI to the ICS is handled after the
+ * CPPR update
+ *
+ * ICP State: Down_CPPR which we handle
+ * in a separate function as it's shared with H_CPPR.
+ */
+ icp_rm_down_cppr(xics, icp, xirr >> 24);
+
+ /* IPIs have no EOI */
+ if (irq == XICS_IPI)
+ return check_too_hard(xics, icp);
+
+ return ics_rm_eoi(vcpu, irq);
+}
+
unsigned long eoi_rc;
static void icp_eoi(struct irq_chip *c, u32 hwirq, __be32 xirr, bool *again)
@@ -823,14 +848,33 @@ long kvmppc_deliver_irq_passthru(struct kvm_vcpu *vcpu,
{
struct kvmppc_xics *xics;
struct kvmppc_icp *icp;
+ struct kvmppc_ics *ics;
+ struct ics_irq_state *state;
u32 irq;
+ u16 src;
+ u32 pq_old, pq_new;
irq = irq_map->v_hwirq;
xics = vcpu->kvm->arch.xics;
icp = vcpu->arch.icp;
kvmppc_rm_handle_irq_desc(irq_map->desc);
- icp_rm_deliver_irq(xics, icp, irq);
+
+ ics = kvmppc_xics_find_ics(xics, irq, &src);
+ if (!ics)
+ return 2;
+
+ state = &ics->irq_state[src];
+
+ /* only MSIs register bypass producers, so it must be MSI here */
+ do {
+ pq_old = state->pq_state;
+ pq_new = ((pq_old << 1) & 3) | PQ_PRESENTED;
+ } while (cmpxchg(&state->pq_state, pq_old, pq_new) != pq_old);
+
+ /* Test P=1, Q=0, this is the only case where we present */
+ if (pq_new == PQ_PRESENTED)
+ icp_rm_deliver_irq(xics, icp, irq, false);
/* EOI the interrupt */
icp_eoi(irq_desc_get_chip(irq_map->desc), irq_map->r_hwirq, xirr,

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