x86: 32 bit: interrupt stub consistency with 64 bit

Don't generate interrupt stubs for interrupt vectors below
FIRST_EXTERNAL_VECTOR, and make the table of interrupt vectors
(interrupt[]) __initconst.  Both of these changes both conserve memory
and improve consistency with 64 bits.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

4 files changed, 7 insertions, 6 deletions

diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index b97aecb0b61d..27d33f92afe2 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -110,7 +110,7 @@ extern asmlinkage void smp_invalidate_interrupt(struct pt_regs *);
 #endif
 
 #ifdef CONFIG_X86_32
-extern void (*const interrupt[NR_VECTORS])(void);
+extern void (*__initconst interrupt[NR_VECTORS-FIRST_EXTERNAL_VECTOR])(void);
 #endif
 
 typedef int vector_irq_t[NR_VECTORS];
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 28b597ef9ca1..4aea95652cff 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -622,16 +622,16 @@ END(syscall_badsys)
  * Build the entry stubs and pointer table with
  * some assembler magic.
  */
-.section .rodata,"a"
+.section .init.rodata,"a"
 ENTRY(interrupt)
 .text
 
 ENTRY(irq_entries_start)
         RING0_INT_FRAME
-vector=0
+vector=FIRST_EXTERNAL_VECTOR
 .rept NR_VECTORS
         ALIGN
- .if vector
+ .if vector != FIRST_EXTERNAL_VECTOR
         CFI_ADJUST_CFA_OFFSET -4
  .endif
 1:      pushl $~(vector)
diff --git a/arch/x86/kernel/irqinit_32.c b/arch/x86/kernel/irqinit_32.c
index 845aa9803e80..607db63044a5 100644
--- a/arch/x86/kernel/irqinit_32.c
+++ b/arch/x86/kernel/irqinit_32.c
@@ -129,7 +129,7 @@ void __init native_init_IRQ(void)
         for (i =  FIRST_EXTERNAL_VECTOR; i < NR_VECTORS; i++) {
                 /* SYSCALL_VECTOR was reserved in trap_init. */
                 if (i != SYSCALL_VECTOR)
-                        set_intr_gate(i, interrupt[i]);
+                        set_intr_gate(i, interrupt[i-FIRST_EXTERNAL_VECTOR]);
         }
 
 
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index a5d8e1ace1cf..50a779264bb1 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -590,7 +590,8 @@ static void __init lguest_init_IRQ(void)
                  * a straightforward 1 to 1 mapping, so force that here. */
                 __get_cpu_var(vector_irq)[vector] = i;
                 if (vector != SYSCALL_VECTOR) {
-                        set_intr_gate(vector, interrupt[vector]);
+                        set_intr_gate(vector,
+                                      interrupt[vector-FIRST_EXTERNAL_VECTOR]);
                         set_irq_chip_and_handler_name(i, &lguest_irq_controller,
                                                       handle_level_irq,
                                                       "level");