Import of Linus's Linux 1.1.68

1 files changed, 165 insertions, 0 deletions

diff --git a/include/asm-i386/irq.h b/include/asm-i386/irq.h
new file mode 100644
index 000000000..d9a45530c
--- /dev/null
+++ b/include/asm-i386/irq.h
@@ -0,0 +1,165 @@
+#ifndef _ASM_IRQ_H
+#define _ASM_IRQ_H
+
+/*
+ *	linux/include/asm/irq.h
+ *
+ *	(C) 1992, 1993 Linus Torvalds
+ */
+
+#include <linux/linkage.h>
+#include <asm/segment.h>
+
+extern void disable_irq(unsigned int);
+extern void enable_irq(unsigned int);
+
+#define __STR(x) #x
+#define STR(x) __STR(x)
+ 
+#define SAVE_ALL \
+	"cld\n\t" \
+	"push %gs\n\t" \
+	"push %fs\n\t" \
+	"push %es\n\t" \
+	"push %ds\n\t" \
+	"pushl %eax\n\t" \
+	"pushl %ebp\n\t" \
+	"pushl %edi\n\t" \
+	"pushl %esi\n\t" \
+	"pushl %edx\n\t" \
+	"pushl %ecx\n\t" \
+	"pushl %ebx\n\t" \
+	"movl $" STR(KERNEL_DS) ",%edx\n\t" \
+	"mov %dx,%ds\n\t" \
+	"mov %dx,%es\n\t" \
+	"movl $" STR(USER_DS) ",%edx\n\t" \
+	"mov %dx,%fs\n\t"   \
+	"movl $0,%edx\n\t"  \
+	"movl %edx,%db7\n\t"
+
+/*
+ * SAVE_MOST/RESTORE_MOST is used for the faster version of IRQ handlers,
+ * installed by using the SA_INTERRUPT flag. These kinds of IRQ's don't
+ * call the routines that do signal handling etc on return, and can have
+ * more relaxed register-saving etc. They are also atomic, and are thus
+ * suited for small, fast interrupts like the serial lines or the harddisk
+ * drivers, which don't actually need signal handling etc.
+ *
+ * Also note that we actually save only those registers that are used in
+ * C subroutines (%eax, %edx and %ecx), so if you do something weird,
+ * you're on your own. The only segments that are saved (not counting the
+ * automatic stack and code segment handling) are %ds and %es, and they
+ * point to kernel space. No messing around with %fs here.
+ */
+#define SAVE_MOST \
+	"cld\n\t" \
+	"push %es\n\t" \
+	"push %ds\n\t" \
+	"pushl %eax\n\t" \
+	"pushl %edx\n\t" \
+	"pushl %ecx\n\t" \
+	"movl $" STR(KERNEL_DS) ",%edx\n\t" \
+	"mov %dx,%ds\n\t" \
+	"mov %dx,%es\n\t"
+
+#define RESTORE_MOST \
+	"popl %ecx\n\t" \
+	"popl %edx\n\t" \
+	"popl %eax\n\t" \
+	"pop %ds\n\t" \
+	"pop %es\n\t" \
+	"iret"
+
+/*
+ * The "inb" instructions are not needed, but seem to change the timings
+ * a bit - without them it seems that the harddisk driver won't work on
+ * all hardware. Arghh.
+ */
+#define ACK_FIRST(mask) \
+	"inb $0x21,%al\n\t" \
+	"jmp 1f\n" \
+	"1:\tjmp 1f\n" \
+	"1:\torb $" #mask ",_cache_21\n\t" \
+	"movb _cache_21,%al\n\t" \
+	"outb %al,$0x21\n\t" \
+	"jmp 1f\n" \
+	"1:\tjmp 1f\n" \
+	"1:\tmovb $0x20,%al\n\t" \
+	"outb %al,$0x20\n\t"
+
+#define ACK_SECOND(mask) \
+	"inb $0xA1,%al\n\t" \
+	"jmp 1f\n" \
+	"1:\tjmp 1f\n" \
+	"1:\torb $" #mask ",_cache_A1\n\t" \
+	"movb _cache_A1,%al\n\t" \
+	"outb %al,$0xA1\n\t" \
+	"jmp 1f\n" \
+	"1:\tjmp 1f\n" \
+	"1:\tmovb $0x20,%al\n\t" \
+	"outb %al,$0xA0\n\t" \
+	"jmp 1f\n" \
+	"1:\tjmp 1f\n" \
+	"1:\toutb %al,$0x20\n\t"
+
+#define UNBLK_FIRST(mask) \
+	"inb $0x21,%al\n\t" \
+	"jmp 1f\n" \
+	"1:\tjmp 1f\n" \
+	"1:\tandb $~(" #mask "),_cache_21\n\t" \
+	"movb _cache_21,%al\n\t" \
+	"outb %al,$0x21\n\t"
+
+#define UNBLK_SECOND(mask) \
+	"inb $0xA1,%al\n\t" \
+	"jmp 1f\n" \
+	"1:\tjmp 1f\n" \
+	"1:\tandb $~(" #mask "),_cache_A1\n\t" \
+	"movb _cache_A1,%al\n\t" \
+	"outb %al,$0xA1\n\t"
+
+#define IRQ_NAME2(nr) nr##_interrupt(void)
+#define IRQ_NAME(nr) IRQ_NAME2(IRQ##nr)
+#define FAST_IRQ_NAME(nr) IRQ_NAME2(fast_IRQ##nr)
+#define BAD_IRQ_NAME(nr) IRQ_NAME2(bad_IRQ##nr)
+	
+#define BUILD_IRQ(chip,nr,mask) \
+asmlinkage void IRQ_NAME(nr); \
+asmlinkage void FAST_IRQ_NAME(nr); \
+asmlinkage void BAD_IRQ_NAME(nr); \
+__asm__( \
+"\n.align 4\n" \
+"_IRQ" #nr "_interrupt:\n\t" \
+	"pushl $-"#nr"-2\n\t" \
+	SAVE_ALL \
+	ACK_##chip(mask) \
+	"incl _intr_count\n\t"\
+	"sti\n\t" \
+	"movl %esp,%ebx\n\t" \
+	"pushl %ebx\n\t" \
+	"pushl $" #nr "\n\t" \
+	"call _do_IRQ\n\t" \
+	"addl $8,%esp\n\t" \
+	"cli\n\t" \
+	UNBLK_##chip(mask) \
+	"decl _intr_count\n\t" \
+	"jmp ret_from_sys_call\n" \
+"\n.align 4\n" \
+"_fast_IRQ" #nr "_interrupt:\n\t" \
+	SAVE_MOST \
+	ACK_##chip(mask) \
+	"incl _intr_count\n\t" \
+	"pushl $" #nr "\n\t" \
+	"call _do_fast_IRQ\n\t" \
+	"addl $4,%esp\n\t" \
+	"cli\n\t" \
+	UNBLK_##chip(mask) \
+	"decl _intr_count\n\t" \
+	RESTORE_MOST \
+"\n\n.align 4\n" \
+"_bad_IRQ" #nr "_interrupt:\n\t" \
+	SAVE_MOST \
+	ACK_##chip(mask) \
+	RESTORE_MOST);
+
+#endif