[PATCH v4 3/3] x86/apic: Drop APIC_EILVT_NR_MAX
From: Naveen N Rao (AMD)
Date: Thu Jul 23 2026 - 01:54:43 EST
Switch to using apic->eilvt_regs_count as the maximum EILVT register
count. Since this value is no longer a compile-time constant, update
eilvt_offsets to be dynamically allocated.
Signed-off-by: Naveen N Rao (AMD) <naveen@xxxxxxxxxx>
Tested-by: Manali Shukla <manali.shukla@xxxxxxx>
---
arch/x86/include/asm/apicdef.h | 1 -
arch/x86/kernel/apic/apic.c | 7 +++++--
2 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/x86/include/asm/apicdef.h b/arch/x86/include/asm/apicdef.h
index ba7657e75ad1..32a242ae0455 100644
--- a/arch/x86/include/asm/apicdef.h
+++ b/arch/x86/include/asm/apicdef.h
@@ -140,7 +140,6 @@
#define APIC_IER 0x480
#define APIC_EILVTn(n) (0x500 + 0x10 * n)
#define APIC_EILVT_NR_AMD_10H 4
-#define APIC_EILVT_NR_MAX APIC_EILVT_NR_AMD_10H
#define APIC_BASE (fix_to_virt(FIX_APIC_BASE))
#define APIC_BASE_MSR 0x800
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index c990f403ec7f..dd734c58b780 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -341,7 +341,7 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
* necessarily a BIOS bug.
*/
-static atomic_t eilvt_offsets[APIC_EILVT_NR_MAX];
+static atomic_t *eilvt_offsets;
static inline int eilvt_entry_is_changeable(unsigned int old, unsigned int new)
{
@@ -354,7 +354,7 @@ static unsigned int reserve_eilvt_offset(int offset, unsigned int new)
{
unsigned int rsvd, vector;
- if (offset >= APIC_EILVT_NR_MAX)
+ if (!eilvt_offsets || offset >= apic->eilvt_regs_count)
return ~0;
rsvd = atomic_read(&eilvt_offsets[offset]);
@@ -417,6 +417,9 @@ static __init void init_eilvt(void)
if (!apic->eilvt_regs_count && boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
apic->eilvt_regs_count = APIC_EILVT_NR_AMD_10H;
+
+ if (apic->eilvt_regs_count)
+ eilvt_offsets = kzalloc_objs(atomic_t, apic->eilvt_regs_count);
}
/*
--
2.54.0