[RFC 3/4] switch static system vector allocation to use vector_irq[]

Dean Nelson
2008-09-11T15:28:46Z

Replace the current use of system_vectors[] for the allocation of static
system vectors by also using the per_cpu variable vector_irq[].

Signed-off-by: Dean Nelson <dcn@sgi.com>

---

arch/x86/kernel/apic.c | 2 --
arch/x86/kernel/io_apic.c | 22 ++++++++++++----------
arch/x86/kernel/irq_32.c | 2 +-
arch/x86/kernel/irq_64.c | 2 +-
include/asm-x86/desc.h | 21 +++++++++++++--------
include/asm-x86/irq.h | 2 ++
include/linux/irq.h | 5 +++++
7 files changed, 34 insertions(+), 22 deletions(-)

Index: linux/arch/x86/kernel/apic.c
===================================================================
--- linux.orig/arch/x86/kernel/apic.c 2008-09-10 12:09:43.000000000 -0500
+++ linux/arch/x86/kernel/apic.c 2008-09-10 12:10:35.000000000 -0500
@@ -119,8 +119,6 @@ EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok
int first_static_system_vector = 0xfe;
int last_device_vector = 0xfd;

-char system_vectors[NR_VECTORS] = { [0 ... NR_VECTORS-1] = SYS_VECTOR_FREE};
-
/*
* Debug level, exported for io_apic.c
*/
Index: linux/include/asm-x86/desc.h
===================================================================
--- linux.orig/include/asm-x86/desc.h 2008-09-10 12:09:43.000000000 -0500
+++ linux/include/asm-x86/desc.h 2008-09-10 12:10:35.000000000 -0500
@@ -6,6 +6,7 @@
#include <asm/ldt.h>
#include <asm/mmu.h>
#include <linux/smp.h>
+#include <linux/irq.h>

static inline void fill_ldt(struct desc_struct *desc,
const struct user_desc *info)
@@ -329,14 +330,18 @@ extern char system_vectors[];

static inline void alloc_static_system_vector(int vector)
{
- if (system_vectors[vector] == SYS_VECTOR_FREE) {
- system_vectors[vector] = SYS_VECTOR_ALLOCED;
- if (first_static_system_vector > vector)
- first_static_system_vector = vector;
- if (last_device_vector > vector - 1)
- last_device_vector = vector - 1;
- } else
- BUG();
+ unsigned long flags;
+ bool ret;
+
+ spin_lock_irqsave(&vector_lock, flags);
+ ret = __grab_irq_vector(NON_IRQ_DESC, vector, &cpu_possible_map);
+ BUG_ON(ret == false);
+
+ if (first_static_system_vector > vector)
+ first_static_system_vector = vector;
+ if (last_device_vector > vector - 1)
+ last_device_vector = vector - 1;
+ spin_unlock_irqrestore(&vector_lock, flags);
}

static inline void alloc_intr_gate(unsigned int n, void *addr)
Index: linux/arch/x86/kernel/io_apic.c
===================================================================
--- linux.orig/arch/x86/kernel/io_apic.c 2008-09-10 12:09:43.000000000 -0500
+++ linux/arch/x86/kernel/io_apic.c 2008-09-10 14:17:12.000000000 -0500
@@ -70,7 +70,7 @@
int sis_apic_bug = -1;

static DEFINE_SPINLOCK(ioapic_lock);
-static DEFINE_SPINLOCK(vector_lock);
+DEFINE_SPINLOCK(vector_lock);

/*
* # of IRQ routing registers
@@ -1221,13 +1221,15 @@ bool __grab_irq_vector(struct irq_desc *
for_each_cpu_mask_nr(cpu, *new_domain_mask)
per_cpu(vector_irq, cpu)[vector] = desc;

- cfg = irq_cfg(desc->irq);
- if (cfg->vector) {
- cfg->move_in_progress = 1;
- cfg->old_domain = cfg->domain;
+ if (desc != NON_IRQ_DESC) {
+ cfg = irq_cfg(desc->irq);
+ if (cfg->vector) {
+ cfg->move_in_progress = 1;
+ cfg->old_domain = cfg->domain;
+ }
+ cfg->vector = vector;
+ cfg->domain = *new_domain_mask;
}
- cfg->vector = vector;
- cfg->domain = *new_domain_mask;

return true;
}
@@ -1387,13 +1389,13 @@ void __setup_vector_irq(int cpu)
continue;
vector = cfg->vector;
desc = irq_to_desc(irq);
- BUG_ON(desc == NULL);
+ BUG_ON(desc == NULL || desc == NON_IRQ_DESC);
per_cpu(vector_irq, cpu)[vector] = desc;
}
/* Mark the free vectors */
for (vector = 0; vector < NR_VECTORS; ++vector) {
desc = per_cpu(vector_irq, cpu)[vector];
- if (desc == NULL)
+ if (desc == NULL || desc == NON_IRQ_DESC)
continue;

cfg = irq_cfg(desc->irq);
@@ -2437,7 +2439,7 @@ asmlinkage void smp_irq_move_cleanup_int
struct irq_cfg *cfg;

desc = __get_cpu_var(vector_irq)[vector];
- if (desc == NULL)
+ if (desc == NULL || desc == NON_IRQ_DESC)
continue;

cfg = irq_cfg(desc->irq);
Index: linux/include/linux/irq.h
===================================================================
--- linux.orig/include/linux/irq.h 2008-09-10 12:09:43.000000000 -0500
+++ linux/include/linux/irq.h 2008-09-10 12:10:35.000000000 -0500
@@ -390,6 +390,11 @@ set_irq_chained_handler(unsigned int irq
extern void set_irq_noprobe(unsigned int irq);
extern void set_irq_probe(unsigned int irq);

+extern bool __grab_irq_vector(struct irq_desc *desc, unsigned int vector,
+ cpumask_t *new_domain_mask);
+
+#define NON_IRQ_DESC ((struct irq_desc *)-1UL)
+
/* Handle dynamic irq device vector allocation and deallocation */
extern unsigned int create_irq_nr(unsigned int irq_want);
extern int create_irq(void);
Index: linux/arch/x86/kernel/irq_32.c
===================================================================
--- linux.orig/arch/x86/kernel/irq_32.c 2008-09-10 12:08:37.000000000 -0500
+++ linux/arch/x86/kernel/irq_32.c 2008-09-10 12:10:35.000000000 -0500
@@ -234,7 +234,7 @@ unsigned int do_IRQ(struct pt_regs *regs
overflow = check_stack_overflow();

desc = __get_cpu_var(vector_irq)[vector];
- if (unlikely(desc == NULL)) {
+ if (unlikely(desc == NULL || desc == NON_IRQ_DESC)) {
printk(KERN_EMERG "%s: cannot handle IRQ vector %#x cpu %d\n",
__func__, vector, smp_processor_id());
BUG();
Index: linux/arch/x86/kernel/irq_64.c
===================================================================
--- linux.orig/arch/x86/kernel/irq_64.c 2008-09-10 12:08:37.000000000 -0500
+++ linux/arch/x86/kernel/irq_64.c 2008-09-10 12:10:35.000000000 -0500
@@ -222,7 +222,7 @@ asmlinkage unsigned int do_IRQ(struct pt
#endif

desc = __get_cpu_var(vector_irq)[vector];
- if (likely(desc != NULL)) {
+ if (likely(desc != NULL && desc != NON_IRQ_DESC)) {
generic_handle_irq_desc(desc->irq, desc);
} else {
if (!disable_apic)
Index: linux/include/asm-x86/irq.h
===================================================================
--- linux.orig/include/asm-x86/irq.h 2008-09-10 12:07:29.000000000 -0500
+++ linux/include/asm-x86/irq.h 2008-09-10 14:22:12.000000000 -0500
@@ -47,4 +47,6 @@ extern void native_init_IRQ(void);
/* Interrupt vector management */
extern DECLARE_BITMAP(used_vectors, NR_VECTORS);

+extern spinlock_t vector_lock;
+
#endif /* ASM_X86__IRQ_H */