[patch V2 03/44] x86/irq: Get rid of the first_system_vector bogisity

Thomas Gleixner
2017-08-25T22:09:16Z

[-- Attachment #1: x86-irq--Get-rid-of-the-first_system_vector-bogisity.patch --]
[-- Type: text/plain, Size: 2996 bytes --]

This variable is beyond pointless. Nothing allocates a vector via
alloc_gate() below FIRST_SYSTEM_VECTOR. So nothing can change
first_system_vector.

If there is a need for a gate below FIRST_SYSTEM_VECTOR then it can be
added to the vector defines and FIRST_SYSTEM_VECTOR adjusted accordingly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/include/asm/desc.h | 5 ++---
arch/x86/kernel/apic/apic.c | 2 --
arch/x86/kernel/apic/vector.c | 2 +-
arch/x86/kernel/irq.c | 2 +-
arch/x86/kernel/irqinit.c | 5 +----
5 files changed, 5 insertions(+), 11 deletions(-)

--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -5,6 +5,7 @@
#include <asm/ldt.h>
#include <asm/mmu.h>
#include <asm/fixmap.h>
+#include <asm/irq_vectors.h>

#include <linux/smp.h>
#include <linux/percpu.h>
@@ -482,16 +483,14 @@ static inline void _set_gate(int gate, u
0, 0, __KERNEL_CS); \
} while (0)

-extern int first_system_vector;
/* used_vectors is BITMAP for irq is not managed by percpu vector_irq */
extern unsigned long used_vectors[];

static inline void alloc_system_vector(int vector)
{
+ BUG_ON(vector < FIRST_SYSTEM_VECTOR);
if (!test_bit(vector, used_vectors)) {
set_bit(vector, used_vectors);
- if (first_system_vector > vector)
- first_system_vector = vector;
} else {
BUG();
}
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -177,8 +177,6 @@ static int disable_apic_timer __initdata
int local_apic_timer_c2_ok;
EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok);

-int first_system_vector = FIRST_SYSTEM_VECTOR;
-
/*
* Debug level, exported for io_apic.c
*/
--- a/arch/x86/kernel/apic/vector.c
+++ b/arch/x86/kernel/apic/vector.c
@@ -166,7 +166,7 @@ static int __assign_irq_vector(int irq,
offset = current_offset;
next:
vector += 16;
- if (vector >= first_system_vector) {
+ if (vector >= FIRST_SYSTEM_VECTOR) {
offset = (offset + 1) % 16;
vector = FIRST_EXTERNAL_VECTOR + offset;
}
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -429,7 +429,7 @@ int check_irq_vectors_for_cpu_disable(vo
* this w/o holding vector_lock.
*/
for (vector = FIRST_EXTERNAL_VECTOR;
- vector < first_system_vector; vector++) {
+ vector < FIRST_SYSTEM_VECTOR; vector++) {
if (!test_bit(vector, used_vectors) &&
IS_ERR_OR_NULL(per_cpu(vector_irq, cpu)[vector])) {
if (++count == this_count)
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -169,10 +169,7 @@ void __init native_init_IRQ(void)
* 'special' SMP interrupts)
*/
i = FIRST_EXTERNAL_VECTOR;
-#ifndef CONFIG_X86_LOCAL_APIC
-#define first_system_vector NR_VECTORS
-#endif
- for_each_clear_bit_from(i, used_vectors, first_system_vector) {
+ for_each_clear_bit_from(i, used_vectors, FIRST_SYSTEM_VECTOR) {
/* IA32_SYSCALL_VECTOR could be used in trap_init already. */
set_intr_gate(i, irq_entries_start +
8 * (i - FIRST_EXTERNAL_VECTOR));