The CPU hotplugging code might re-trigger a vector. In that case the
vector is in the VECTOR_RETRIGGERED state. With this patch applied ipipe
does no longer call BUG() for such vectors.
This is a backport from the 4.19 and 5.4 ipipe branches handling the
VECTOR_SHUTDOWN state. The VECTOR_SHUTDOWN case itself does not exist in
4.4, but the VECTOR_RETRIGGERED case does.
__ipipe_handle_irq() is now synchronized with do_IRQ().
Signed-off-by: Florian Bezdeka <florian.bezd...@siemens.com>
---
arch/x86/kernel/ipipe.c | 44 +++++++++++++++++++++++++++++++----------
1 file changed, 34 insertions(+), 10 deletions(-)
diff --git a/arch/x86/kernel/ipipe.c b/arch/x86/kernel/ipipe.c
index 739b5c37ec7b..6020739256f9 100644
--- a/arch/x86/kernel/ipipe.c
+++ b/arch/x86/kernel/ipipe.c
@@ -33,6 +33,7 @@
#include <linux/mm.h>
#include <linux/kgdb.h>
#include <linux/ipipe_tickdev.h>
+#include <linux/ratelimit.h>
#include <asm/asm-offsets.h>
#include <asm/unistd.h>
#include <asm/processor.h>
@@ -428,22 +429,44 @@ skip_kgdb:
return 0;
}
+static inline int __ipipe_irq_from_vector(int vector, int *irq)
+{
+ struct irq_desc *desc;
+
+ if (vector >= FIRST_SYSTEM_VECTOR) {
+ *irq = ipipe_apic_vector_irq(vector);
+ return 0;
+ }
+
+ desc = __this_cpu_read(vector_irq[vector]);
+ if (likely(!IS_ERR_OR_NULL(desc))) {
+ *irq = irq_desc_get_irq(desc);
+ return 0;
+ }
+
+#ifdef CONFIG_X86_LOCAL_APIC
+ __ack_APIC_irq();
+#endif
+
+ if (desc == VECTOR_UNUSED) {
+ pr_emerg_ratelimited("%s: %d.%d Unexpected IRQ trap\n",
+ __func__, smp_processor_id(), vector);
+ } else {
+ __this_cpu_write(vector_irq[vector], VECTOR_UNUSED);
+ }
+
+ return -1;
+}
+
int __ipipe_handle_irq(struct pt_regs *regs)
{
struct ipipe_percpu_data *p = __ipipe_raw_cpu_ptr(&ipipe_percpu);
int irq, vector = regs->orig_ax, flags = 0;
struct pt_regs *tick_regs;
- struct irq_desc *desc;
if (likely(vector < 0)) {
- vector = ~vector;
- if (vector >= FIRST_SYSTEM_VECTOR)
- irq = ipipe_apic_vector_irq(vector);
- else {
- desc = __this_cpu_read(vector_irq[vector]);
- BUG_ON(IS_ERR_OR_NULL(desc));
- irq = irq_desc_get_irq(desc);
- }
+ if (__ipipe_irq_from_vector(~vector, &irq) < 0)
+ goto out;
} else { /* Software-generated. */
irq = vector;
flags = IPIPE_IRQF_NOACK;
@@ -477,7 +500,8 @@ int __ipipe_handle_irq(struct pt_regs *regs)
__ipipe_call_mayday(regs);
ipipe_trace_irqend(irq, regs);
-
+
+out:
if (!__ipipe_root_p ||
test_bit(IPIPE_STALL_FLAG, &__ipipe_root_status))
return 0;
--
2.30.2
