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authorMichael Ellerman <mpe@ellerman.id.au>2019-08-19 13:19:43 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2019-08-19 13:19:43 +1000
commit1a47908e0f81803115d679271a64d84351c91870 (patch)
tree26f23189be6a11ea245f5ce033511e6801d67739 /arch/powerpc/sysdev
parent4215fa2d7d3a872c4f6f383dc52961215b0ce2d6 (diff)
parentda15c03b047dca891d37b9f4ef9ca14d84a6484f (diff)
downloadlinux-1a47908e0f81803115d679271a64d84351c91870.tar.bz2
Merge branch 'topic/ppc-kvm' into next
Merge our ppc-kvm topic branch. This contains several fixes for the XIVE interrupt controller that we are sharing with the KVM tree.
Diffstat (limited to 'arch/powerpc/sysdev')
-rw-r--r--arch/powerpc/sysdev/xive/common.c87
1 files changed, 64 insertions, 23 deletions
diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index 083f657091d7..6b973b7cdd8a 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -135,7 +135,7 @@ static u32 xive_read_eq(struct xive_q *q, bool just_peek)
static u32 xive_scan_interrupts(struct xive_cpu *xc, bool just_peek)
{
u32 irq = 0;
- u8 prio;
+ u8 prio = 0;
/* Find highest pending priority */
while (xc->pending_prio != 0) {
@@ -148,8 +148,19 @@ static u32 xive_scan_interrupts(struct xive_cpu *xc, bool just_peek)
irq = xive_read_eq(&xc->queue[prio], just_peek);
/* Found something ? That's it */
- if (irq)
- break;
+ if (irq) {
+ if (just_peek || irq_to_desc(irq))
+ break;
+ /*
+ * We should never get here; if we do then we must
+ * have failed to synchronize the interrupt properly
+ * when shutting it down.
+ */
+ pr_crit("xive: got interrupt %d without descriptor, dropping\n",
+ irq);
+ WARN_ON(1);
+ continue;
+ }
/* Clear pending bits */
xc->pending_prio &= ~(1 << prio);
@@ -307,6 +318,7 @@ static void xive_do_queue_eoi(struct xive_cpu *xc)
*/
static void xive_do_source_eoi(u32 hw_irq, struct xive_irq_data *xd)
{
+ xd->stale_p = false;
/* If the XIVE supports the new "store EOI facility, use it */
if (xd->flags & XIVE_IRQ_FLAG_STORE_EOI)
xive_esb_write(xd, XIVE_ESB_STORE_EOI, 0);
@@ -350,7 +362,7 @@ static void xive_do_source_eoi(u32 hw_irq, struct xive_irq_data *xd)
}
}
-/* irq_chip eoi callback */
+/* irq_chip eoi callback, called with irq descriptor lock held */
static void xive_irq_eoi(struct irq_data *d)
{
struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
@@ -366,6 +378,8 @@ static void xive_irq_eoi(struct irq_data *d)
if (!irqd_irq_disabled(d) && !irqd_is_forwarded_to_vcpu(d) &&
!(xd->flags & XIVE_IRQ_NO_EOI))
xive_do_source_eoi(irqd_to_hwirq(d), xd);
+ else
+ xd->stale_p = true;
/*
* Clear saved_p to indicate that it's no longer occupying
@@ -397,11 +411,16 @@ static void xive_do_source_set_mask(struct xive_irq_data *xd,
*/
if (mask) {
val = xive_esb_read(xd, XIVE_ESB_SET_PQ_01);
- xd->saved_p = !!(val & XIVE_ESB_VAL_P);
- } else if (xd->saved_p)
+ if (!xd->stale_p && !!(val & XIVE_ESB_VAL_P))
+ xd->saved_p = true;
+ xd->stale_p = false;
+ } else if (xd->saved_p) {
xive_esb_read(xd, XIVE_ESB_SET_PQ_10);
- else
+ xd->saved_p = false;
+ } else {
xive_esb_read(xd, XIVE_ESB_SET_PQ_00);
+ xd->stale_p = false;
+ }
}
/*
@@ -541,6 +560,8 @@ static unsigned int xive_irq_startup(struct irq_data *d)
unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
int target, rc;
+ xd->saved_p = false;
+ xd->stale_p = false;
pr_devel("xive_irq_startup: irq %d [0x%x] data @%p\n",
d->irq, hw_irq, d);
@@ -587,6 +608,7 @@ static unsigned int xive_irq_startup(struct irq_data *d)
return 0;
}
+/* called with irq descriptor lock held */
static void xive_irq_shutdown(struct irq_data *d)
{
struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
@@ -602,16 +624,6 @@ static void xive_irq_shutdown(struct irq_data *d)
xive_do_source_set_mask(xd, true);
/*
- * The above may have set saved_p. We clear it otherwise it
- * will prevent re-enabling later on. It is ok to forget the
- * fact that the interrupt might be in a queue because we are
- * accounting that already in xive_dec_target_count() and will
- * be re-routing it to a new queue with proper accounting when
- * it's started up again
- */
- xd->saved_p = false;
-
- /*
* Mask the interrupt in HW in the IVT/EAS and set the number
* to be the "bad" IRQ number
*/
@@ -797,6 +809,10 @@ static int xive_irq_retrigger(struct irq_data *d)
return 1;
}
+/*
+ * Caller holds the irq descriptor lock, so this won't be called
+ * concurrently with xive_get_irqchip_state on the same interrupt.
+ */
static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state)
{
struct xive_irq_data *xd = irq_data_get_irq_handler_data(d);
@@ -820,6 +836,10 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state)
/* Set it to PQ=10 state to prevent further sends */
pq = xive_esb_read(xd, XIVE_ESB_SET_PQ_10);
+ if (!xd->stale_p) {
+ xd->saved_p = !!(pq & XIVE_ESB_VAL_P);
+ xd->stale_p = !xd->saved_p;
+ }
/* No target ? nothing to do */
if (xd->target == XIVE_INVALID_TARGET) {
@@ -827,7 +847,7 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state)
* An untargetted interrupt should have been
* also masked at the source
*/
- WARN_ON(pq & 2);
+ WARN_ON(xd->saved_p);
return 0;
}
@@ -847,9 +867,8 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state)
* This saved_p is cleared by the host EOI, when we know
* for sure the queue slot is no longer in use.
*/
- if (pq & 2) {
- pq = xive_esb_read(xd, XIVE_ESB_SET_PQ_11);
- xd->saved_p = true;
+ if (xd->saved_p) {
+ xive_esb_read(xd, XIVE_ESB_SET_PQ_11);
/*
* Sync the XIVE source HW to ensure the interrupt
@@ -862,8 +881,7 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state)
*/
if (xive_ops->sync_source)
xive_ops->sync_source(hw_irq);
- } else
- xd->saved_p = false;
+ }
} else {
irqd_clr_forwarded_to_vcpu(d);
@@ -914,6 +932,23 @@ static int xive_irq_set_vcpu_affinity(struct irq_data *d, void *state)
return 0;
}
+/* Called with irq descriptor lock held. */
+static int xive_get_irqchip_state(struct irq_data *data,
+ enum irqchip_irq_state which, bool *state)
+{
+ struct xive_irq_data *xd = irq_data_get_irq_handler_data(data);
+
+ switch (which) {
+ case IRQCHIP_STATE_ACTIVE:
+ *state = !xd->stale_p &&
+ (xd->saved_p ||
+ !!(xive_esb_read(xd, XIVE_ESB_GET) & XIVE_ESB_VAL_P));
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
static struct irq_chip xive_irq_chip = {
.name = "XIVE-IRQ",
.irq_startup = xive_irq_startup,
@@ -925,6 +960,7 @@ static struct irq_chip xive_irq_chip = {
.irq_set_type = xive_irq_set_type,
.irq_retrigger = xive_irq_retrigger,
.irq_set_vcpu_affinity = xive_irq_set_vcpu_affinity,
+ .irq_get_irqchip_state = xive_get_irqchip_state,
};
bool is_xive_irq(struct irq_chip *chip)
@@ -1338,6 +1374,11 @@ static void xive_flush_cpu_queue(unsigned int cpu, struct xive_cpu *xc)
xd = irq_desc_get_handler_data(desc);
/*
+ * Clear saved_p to indicate that it's no longer pending
+ */
+ xd->saved_p = false;
+
+ /*
* For LSIs, we EOI, this will cause a resend if it's
* still asserted. Otherwise do an MSI retrigger.
*/