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[Qemu-devel] [PATCH] apic: Implement low-priority arbitration for IRQ de
From: |
James Sullivan |
Subject: |
[Qemu-devel] [PATCH] apic: Implement low-priority arbitration for IRQ delivery |
Date: |
Mon, 23 Mar 2015 16:26:12 -0600 |
Currently, there is no arbitration among processors for low priority IRQ
delivery. Implemented apic_get_arb_pri(), and added two new functions
apic_compare_prio() and apic_lowest_prio() to support arbitration in
apic_bus_deliver().
Signed-off-by: James Sullivan <address@hidden>
---
hw/intc/apic.c | 67 ++++++++++++++++++++++++++++++++++++++++++----------------
1 file changed, 49 insertions(+), 18 deletions(-)
diff --git a/hw/intc/apic.c b/hw/intc/apic.c
index 0f97b47..47d2fb1 100644
--- a/hw/intc/apic.c
+++ b/hw/intc/apic.c
@@ -38,6 +38,7 @@ static void apic_set_irq(APICCommonState *s, int vector_num,
int trigger_mode);
static void apic_update_irq(APICCommonState *s);
static void apic_get_delivery_bitmask(uint32_t *deliver_bitmask,
uint8_t dest, uint8_t dest_mode);
+static int apic_get_arb_pri(APICCommonState *s);
/* Find first bit starting from msb */
static int apic_fls_bit(uint32_t value)
@@ -199,6 +200,29 @@ static void apic_external_nmi(APICCommonState *s)
apic_local_deliver(s, APIC_LVT_LINT1);
}
+static int apic_compare_prio(struct APICCommonState *cpu1,
+ struct APICCommonState *cpu2)
+{
+ return apic_get_arb_pri(cpu1) - apic_get_arb_pri(cpu2);
+}
+
+static struct APICCommonState *apic_lowest_prio(const uint32_t
+ *deliver_bitmask)
+{
+ APICCommonState *lowest = NULL;
+ int i, d;
+
+ for (i = 0; i < MAX_APIC_WORDS; i++) {
+ if (deliver_bitmask[i]) {
+ d = i * 32 + apic_ffs_bit(deliver_bitmask[i]);
+ if (!lowest || apic_compare_prio(local_apics[d], lowest) < 0) {
+ lowest = local_apics[d];
+ }
+ }
+ }
+ return lowest;
+}
+
#define foreach_apic(apic, deliver_bitmask, code) \
{\
int __i, __j;\
@@ -225,22 +249,10 @@ static void apic_bus_deliver(const uint32_t
*deliver_bitmask,
switch (delivery_mode) {
case APIC_DM_LOWPRI:
- /* XXX: search for focus processor, arbitration */
- {
- int i, d;
- d = -1;
- for(i = 0; i < MAX_APIC_WORDS; i++) {
- if (deliver_bitmask[i]) {
- d = i * 32 + apic_ffs_bit(deliver_bitmask[i]);
- break;
- }
- }
- if (d >= 0) {
- apic_iter = local_apics[d];
- if (apic_iter) {
- apic_set_irq(apic_iter, vector_num, trigger_mode);
- }
- }
+ /* XXX: search for focus processor */
+ apic_iter = apic_lowest_prio(deliver_bitmask);
+ if (apic_iter) {
+ apic_set_irq(apic_iter , vector_num, trigger_mode);
}
return;
@@ -336,8 +348,27 @@ static int apic_get_ppr(APICCommonState *s)
static int apic_get_arb_pri(APICCommonState *s)
{
- /* XXX: arbitration */
- return 0;
+ int tpr, isrv, irrv, apr;
+
+ tpr = apic_get_tpr(s);
+ isrv = get_highest_priority_int(s->isr);
+ if (isrv < 0) {
+ isrv = 0;
+ }
+ isrv >>= 4;
+ irrv = get_highest_priority_int(s->irr);
+ if (irrv < 0) {
+ irrv = 0;
+ }
+ irrv >>= 4;
+
+ if ((tpr >= irrv) && (tpr > isrv)) {
+ apr = s->tpr & 0xff;
+ } else {
+ apr = ((tpr & isrv) > irrv) ? (tpr & isrv) : irrv;
+ apr <<= 4;
+ }
+ return apr;
}
--
2.3.3
- [Qemu-devel] [PATCH] apic: Implement low-priority arbitration for IRQ delivery,
James Sullivan <=