[PATCH] x86: fix lguest used_vectors breakage -v2

Yinghai Lu
2008-12-19T23:24:53Z

Impact: fix lguest, clean up

32-bit lguest used used_vectors to record vectors, but that model of
allocating vectors changed and got broken, after we changed vector
allocation to a per_cpu array.

Try enable that for 64bit, and the array is used for all vectors that
are not managed by vector_irq per_cpu array.

Also kill system_vectors[], that is now a duplication of the
used_vectors bitmap.

[ merged in cpus4096 due to io_apic.c cpumask changes. ]

Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---
arch/x86/include/asm/desc.h | 10 ++++------
arch/x86/include/asm/irq.h | 1 +
arch/x86/kernel/apic.c | 2 --
arch/x86/kernel/io_apic.c | 9 +++------
arch/x86/kernel/irqinit_32.c | 16 +++++++++++++++-
arch/x86/kernel/irqinit_64.c | 13 +++++++++++++
arch/x86/kernel/traps.c | 12 +++++++-----
drivers/lguest/interrupts_and_traps.c | 13 +++++++++----
8 files changed, 52 insertions(+), 24 deletions(-)

Index: linux-2.6/arch/x86/include/asm/desc.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/desc.h
+++ linux-2.6/arch/x86/include/asm/desc.h
@@ -320,16 +320,14 @@ static inline void set_intr_gate(unsigne
_set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS);
}

-#define SYS_VECTOR_FREE 0
-#define SYS_VECTOR_ALLOCED 1
-
extern int first_system_vector;
-extern char system_vectors[];
+/* 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)
{
- if (system_vectors[vector] == SYS_VECTOR_FREE) {
- system_vectors[vector] = SYS_VECTOR_ALLOCED;
+ if (!test_bit(vector, used_vectors)) {
+ set_bit(vector, used_vectors);
if (first_system_vector > vector)
first_system_vector = vector;
} else
Index: linux-2.6/arch/x86/include/asm/irq.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/irq.h
+++ linux-2.6/arch/x86/include/asm/irq.h
@@ -42,5 +42,6 @@ extern void native_init_IRQ(void);

/* Interrupt vector management */
extern DECLARE_BITMAP(used_vectors, NR_VECTORS);
+extern int vector_used_by_percpu_irq(unsigned int vector);

#endif /* _ASM_X86_IRQ_H */
Index: linux-2.6/arch/x86/kernel/apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/apic.c
+++ linux-2.6/arch/x86/kernel/apic.c
@@ -120,8 +120,6 @@ EXPORT_SYMBOL_GPL(local_apic_timer_c2_ok

int first_system_vector = 0xfe;

-char system_vectors[NR_VECTORS] = { [0 ... NR_VECTORS-1] = SYS_VECTOR_FREE};
-
/*
* Debug level, exported for io_apic.c
*/
Index: linux-2.6/arch/x86/kernel/io_apic.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/io_apic.c
+++ linux-2.6/arch/x86/kernel/io_apic.c
@@ -1326,13 +1326,10 @@ next:
}
if (unlikely(current_vector == vector))
continue;
-#ifdef CONFIG_X86_64
- if (vector == IA32_SYSCALL_VECTOR)
+
+ if (test_bit(vector, used_vectors))
goto next;
-#else
- if (vector == SYSCALL_VECTOR)
- goto next;
-#endif
+
for_each_cpu_and(new_cpu, tmp_mask, cpu_online_mask)
if (per_cpu(vector_irq, new_cpu)[vector] != -1)
goto next;
Index: linux-2.6/arch/x86/kernel/irqinit_32.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/irqinit_32.c
+++ linux-2.6/arch/x86/kernel/irqinit_32.c
@@ -110,6 +110,18 @@ DEFINE_PER_CPU(vector_irq_t, vector_irq)
[IRQ15_VECTOR + 1 ... NR_VECTORS - 1] = -1
};

+int vector_used_by_percpu_irq(unsigned int vector)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu) {
+ if (per_cpu(vector_irq, cpu)[vector] != -1)
+ return 1;
+ }
+
+ return 0;
+}
+
/* Overridden in paravirt.c */
void init_IRQ(void) __attribute__((weak, alias("native_init_IRQ")));

@@ -146,10 +158,12 @@ void __init native_init_IRQ(void)
alloc_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);

/* IPI for single call function */
- set_intr_gate(CALL_FUNCTION_SINGLE_VECTOR, call_function_single_interrupt);
+ alloc_intr_gate(CALL_FUNCTION_SINGLE_VECTOR,
+ call_function_single_interrupt);

/* Low priority IPI to cleanup after moving an irq */
set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt);
+ set_bit(IRQ_MOVE_CLEANUP_VECTOR, used_vectors);
#endif

#ifdef CONFIG_X86_LOCAL_APIC
Index: linux-2.6/arch/x86/kernel/irqinit_64.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/irqinit_64.c
+++ linux-2.6/arch/x86/kernel/irqinit_64.c
@@ -69,6 +69,18 @@ DEFINE_PER_CPU(vector_irq_t, vector_irq)
[IRQ15_VECTOR + 1 ... NR_VECTORS - 1] = -1
};

+int vector_used_by_percpu_irq(unsigned int vector)
+{
+ int cpu;
+
+ for_each_online_cpu(cpu) {
+ if (per_cpu(vector_irq, cpu)[vector] != -1)
+ return 1;
+ }
+
+ return 0;
+}
+
void __init init_ISA_irqs(void)
{
int i;
@@ -121,6 +133,7 @@ static void __init smp_intr_init(void)

/* Low priority IPI to cleanup after moving an irq */
set_intr_gate(IRQ_MOVE_CLEANUP_VECTOR, irq_move_cleanup_interrupt);
+ set_bit(IRQ_MOVE_CLEANUP_VECTOR, used_vectors);
#endif
}

Index: linux-2.6/arch/x86/kernel/traps.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/traps.c
+++ linux-2.6/arch/x86/kernel/traps.c
@@ -73,9 +73,6 @@

#include "cpu/mcheck/mce.h"

-DECLARE_BITMAP(used_vectors, NR_VECTORS);
-EXPORT_SYMBOL_GPL(used_vectors);
-
asmlinkage int system_call(void);

/* Do we ignore FPU interrupts ? */
@@ -90,6 +87,9 @@ gate_desc idt_table[256]
__attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
#endif

+DECLARE_BITMAP(used_vectors, NR_VECTORS);
+EXPORT_SYMBOL_GPL(used_vectors);
+
static int ignore_nmis;

static inline void conditional_sti(struct pt_regs *regs)
@@ -950,9 +950,7 @@ dotraplinkage void do_iret_error(struct

void __init trap_init(void)
{
-#ifdef CONFIG_X86_32
int i;
-#endif

#ifdef CONFIG_EISA
void __iomem *p = early_ioremap(0x0FFFD9, 4);
@@ -1009,11 +1007,15 @@ void __init trap_init(void)
}

set_system_trap_gate(SYSCALL_VECTOR, &system_call);
+#endif

/* Reserve all the builtin and the syscall vector: */
for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
set_bit(i, used_vectors);

+#ifdef CONFIG_X86_64
+ set_bit(IA32_SYSCALL_VECTOR, used_vectors);
+#else
set_bit(SYSCALL_VECTOR, used_vectors);
#endif
/*
Index: linux-2.6/drivers/lguest/interrupts_and_traps.c
===================================================================
--- linux-2.6.orig/drivers/lguest/interrupts_and_traps.c
+++ linux-2.6/drivers/lguest/interrupts_and_traps.c
@@ -222,11 +222,16 @@ bool check_syscall_vector(struct lguest
int init_interrupts(void)
{
/* If they want some strange system call vector, reserve it now */
- if (syscall_vector != SYSCALL_VECTOR
- && test_and_set_bit(syscall_vector, used_vectors)) {
- printk("lg: couldn't reserve syscall %u\n", syscall_vector);
- return -EBUSY;
+ if (syscall_vector != SYSCALL_VECTOR) {
+ if (test_bit(syscall_vector, used_vectors) ||
+ vector_used_by_percpu_irq(syscall_vector)) {
+ printk(KERN_ERR "lg: couldn't reserve syscall %u\n",
+ syscall_vector);
+ return -EBUSY;
+ }
+ set_bit(syscall_vector, used_vectors);
}
+
return 0;
}