[tip: x86/irq] x86/irq: Factor out common code for checking pending interrupts

From: tip-bot2 for Jacob Pan
Date: Tue Apr 30 2024 - 09:28:56 EST


The following commit has been merged into the x86/irq branch of tip:

Commit-ID: fef05a078b6fa1e9047e0486f1f6daf70664fd12
Gitweb: https://git.kernel.org/tip/fef05a078b6fa1e9047e0486f1f6daf70664fd12
Author: Jacob Pan <jacob.jun.pan@xxxxxxxxxxxxxxx>
AuthorDate: Tue, 23 Apr 2024 10:41:11 -07:00
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Tue, 30 Apr 2024 00:54:43 +02:00

x86/irq: Factor out common code for checking pending interrupts

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@xxxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20240423174114.526704-10-jacob.jun.pan@xxxxxxxxxxxxxxx

---
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 e6ab0cf..50f9781 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 185738c..9eec529 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 578e4f6..385e3a5 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);