[PATCH v3 09/12] x86/irq: Factor out common code for checking pending interrupts

Jacob Pan
2024-04-23T17:36:57Z

Use a common function for checking pending interrupt vector in APIC IRR
instead of duplicated open coding them.

Additional checks for posted MSI vectors can then be contained in this
function.

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
arch/x86/include/asm/apic.h | 11 +++++++++++
arch/x86/kernel/apic/vector.c | 5 ++---
arch/x86/kernel/irq.c | 5 ++---
3 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index e6ab0cf15ed5..50f9781fa3ed 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -500,6 +500,17 @@ static inline bool lapic_vector_set_in_irr(unsigned int vector)
return !!(irr & (1U << (vector % 32)));
}

+static inline bool is_vector_pending(unsigned int vector)
+{
+ unsigned int irr;
+
+ irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
+ if (irr & (1 << (vector % 32)))
+ return true;
+
+ return false;
+}
+
/*
* Warm reset vector position:
*/
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 185738c72766..9eec52925fa3 100644
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -965,7 +965,7 @@ static void __vector_cleanup(struct vector_cleanup *cl, bool check_irr)
lockdep_assert_held(&vector_lock);

hlist_for_each_entry_safe(apicd, tmp, &cl->head, clist) {
- unsigned int irr, vector = apicd->prev_vector;
+ unsigned int vector = apicd->prev_vector;

/*
* Paranoia: Check if the vector that needs to be cleaned
@@ -979,8 +979,7 @@ static void __vector_cleanup(struct vector_cleanup *cl, bool check_irr)
* fixup_irqs() was just called to scan IRR for set bits and
* forward them to new destination CPUs via IPIs.
*/
- irr = check_irr ? apic_read(APIC_IRR + (vector / 32 * 0x10)) : 0;
- if (irr & (1U << (vector % 32))) {
+ if (check_irr && is_vector_pending(vector)) {
pr_warn_once("Moved interrupt pending in old target APIC %u\n", apicd->irq);
rearm = true;
continue;
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 578e4f6a5080..385e3a5fc304 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -484,7 +484,7 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_posted_msi_notification)
/* A cpu has been removed from cpu_online_mask. Reset irq affinities. */
void fixup_irqs(void)
{
- unsigned int irr, vector;
+ unsigned int vector;
struct irq_desc *desc;
struct irq_data *data;
struct irq_chip *chip;
@@ -511,8 +511,7 @@ void fixup_irqs(void)
if (IS_ERR_OR_NULL(__this_cpu_read(vector_irq[vector])))
continue;

- irr = apic_read(APIC_IRR + (vector / 32 * 0x10));
- if (irr & (1 << (vector % 32))) {
+ if (is_vector_pending(vector)) {
desc = __this_cpu_read(vector_irq[vector]);

raw_spin_lock(&desc->lock);
--
2.25.1