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x86/irq: Get rid of the 'first_system_vector' indirection bogosity 

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 can be adjusted
accordingly.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064956.357109735@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Thomas Gleixner 2017-08-28 08:47:18 +02:00 committed by Ingo Molnar
parent fa4ab5774d
commit 05161b9cbe
5 changed files with 5 additions and 11 deletions
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5
arch/x86/include/asm/desc.h
View File

@ -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, unsigned type, void *addr,
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();
}

2
arch/x86/kernel/apic/apic.c
View File

@ -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
*/

2
arch/x86/kernel/apic/vector.c
View File

@ -166,7 +166,7 @@ static int __assign_irq_vector(int irq, struct apic_chip_data *d,
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;
}

2
arch/x86/kernel/irq.c
View File

@ -429,7 +429,7 @@ int check_irq_vectors_for_cpu_disable(void)
* 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)

5
arch/x86/kernel/irqinit.c
View File

@ -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));