-#include "interrupt.h"
+#include "threads/interrupt.h"
+#include <debug.h>
#include <inttypes.h>
#include <stdint.h>
-#include "intr-stubs.h"
-#include "debug.h"
-#include "gdt.h"
-#include "io.h"
-#include "lib.h"
-#include "mmu.h"
-#include "thread.h"
-#include "timer.h"
+#include <stdio.h>
+#include "threads/flags.h"
+#include "threads/intr-stubs.h"
+#include "threads/io.h"
+#include "threads/mmu.h"
+#include "threads/thread.h"
+#include "devices/timer.h"
/* Number of x86 interrupts. */
#define INTR_CNT 256
/* Interrupt Descriptor Table helpers. */
static uint64_t make_intr_gate (void (*) (void), int dpl);
static uint64_t make_trap_gate (void (*) (void), int dpl);
+static inline uint64_t make_idtr_operand (uint16_t limit, void *base);
/* Interrupt handlers. */
void intr_handler (struct intr_frame *args);
-static intr_handler_func panic NO_RETURN;
-static intr_handler_func kill NO_RETURN;
\f
/* Returns the current interrupt status. */
enum intr_level
intr_get_level (void)
{
uint32_t flags;
-
- asm ("pushfl; popl %0" : "=g" (flags));
+
+ /* Push the flags register on the processor stack, then pop the
+ value off the stack into `flags'. See [IA32-v2b] "PUSHF"
+ and "POP" and [IA32-v3] 5.8.1. */
+ asm volatile ("pushfl; popl %0" : "=g" (flags));
return flags & FLAG_IF ? INTR_ON : INTR_OFF;
}
intr_enable (void)
{
enum intr_level old_level = intr_get_level ();
+ ASSERT (!intr_context ());
+
+ /* Enable interrupts by setting the interrupt flag.
+ See [IA32-v2b] "STI" and [IA32-v3] 5.8.1. */
asm volatile ("sti");
+
return old_level;
}
intr_disable (void)
{
enum intr_level old_level = intr_get_level ();
+
+ /* Disable interrupts by clearing the interrupt flag.
+ See [IA32-v2b] "CLI" and [IA32-v3] 5.8.1. */
asm volatile ("cli");
+
return old_level;
}
\f
uint64_t idtr_operand;
int i;
+ /* Initialize interrupt controller. */
pic_init ();
- /* Initialize intr_names. */
+ /* Initialize IDT. */
for (i = 0; i < INTR_CNT; i++)
- intr_names[i] = "unknown";
+ idt[i] = make_intr_gate (intr_stubs[i], 0);
- /* Most exceptions require ring 0.
- Exceptions 3, 4, and 5 can be caused by ring 3 directly. */
- intr_register (0, 0, INTR_ON, kill, "#DE Divide Error");
- intr_register (1, 0, INTR_ON, kill, "#DB Debug Exception");
- intr_register (2, 0, INTR_ON, panic, "NMI Interrupt");
- intr_register (3, 3, INTR_ON, kill, "#BP Breakpoint Exception");
- intr_register (4, 3, INTR_ON, kill, "#OF Overflow Exception");
- intr_register (5, 3, INTR_ON, kill, "#BR BOUND Range Exceeded Exception");
- intr_register (6, 0, INTR_ON, kill, "#UD Invalid Opcode Exception");
- intr_register (7, 0, INTR_ON, kill, "#NM Device Not Available Exception");
- intr_register (8, 0, INTR_ON, panic, "#DF Double Fault Exception");
- intr_register (9, 0, INTR_ON, panic, "Coprocessor Segment Overrun");
- intr_register (10, 0, INTR_ON, panic, "#TS Invalid TSS Exception");
- intr_register (11, 0, INTR_ON, kill, "#NP Segment Not Present");
- intr_register (12, 0, INTR_ON, kill, "#SS Stack Fault Exception");
- intr_register (13, 0, INTR_ON, kill, "#GP General Protection Exception");
- intr_register (16, 0, INTR_ON, kill, "#MF x87 FPU Floating-Point Error");
- intr_register (17, 0, INTR_ON, panic, "#AC Alignment Check Exception");
- intr_register (18, 0, INTR_ON, panic, "#MC Machine-Check Exception");
- intr_register (19, 0, INTR_ON, kill, "#XF SIMD Floating-Point Exception");
-
- /* Most exceptions can be handled with interrupts turned on.
- We need to disable interrupts for page faults because the
- fault address is stored in CR2 and needs to be preserved. */
- intr_register (14, 0, INTR_OFF, kill, "#PF Page-Fault Exception");
-
- idtr_operand = make_dtr_operand (sizeof idt - 1, idt);
+ /* Load IDT register.
+ See [IA32-v2a] "LIDT" and [IA32-v3] 5.10. */
+ idtr_operand = make_idtr_operand (sizeof idt - 1, idt);
asm volatile ("lidt %0" :: "m" (idtr_operand));
+
+ /* Initialize intr_names. */
+ for (i = 0; i < INTR_CNT; i++)
+ intr_names[i] = "unknown";
+ intr_names[0] = "#DE Divide Error";
+ intr_names[1] = "#DB Debug Exception";
+ intr_names[2] = "NMI Interrupt";
+ intr_names[3] = "#BP Breakpoint Exception";
+ intr_names[4] = "#OF Overflow Exception";
+ intr_names[5] = "#BR BOUND Range Exceeded Exception";
+ intr_names[6] = "#UD Invalid Opcode Exception";
+ intr_names[7] = "#NM Device Not Available Exception";
+ intr_names[8] = "#DF Double Fault Exception";
+ intr_names[9] = "Coprocessor Segment Overrun";
+ intr_names[10] = "#TS Invalid TSS Exception";
+ intr_names[11] = "#NP Segment Not Present";
+ intr_names[12] = "#SS Stack Fault Exception";
+ intr_names[13] = "#GP General Protection Exception";
+ intr_names[14] = "#PF Page-Fault Exception";
+ intr_names[16] = "#MF x87 FPU Floating-Point Error";
+ intr_names[17] = "#AC Alignment Check Exception";
+ intr_names[18] = "#MC Machine-Check Exception";
+ intr_names[19] = "#XF SIMD Floating-Point Exception";
}
/* Registers interrupt VEC_NO to invoke HANDLER, which is named
{
return make_gate (function, dpl, 15);
}
+
+/* Returns a descriptor that yields the given LIMIT and BASE when
+ used as an operand for the LIDT instruction. */
+static inline uint64_t
+make_idtr_operand (uint16_t limit, void *base)
+{
+ return limit | ((uint64_t) (uint32_t) base << 16);
+}
\f
/* Interrupt handlers. */
-static void dump_intr_frame (struct intr_frame *);
-
/* Handler for all interrupts, faults, and exceptions. This
function is called by the assembly language interrupt stubs in
- intr-stubs.S (see intr-stubs.pl). ARGS describes the
+ intr-stubs.S (see intr-stubs.pl). FRAME describes the
interrupt and the interrupted thread's registers. */
void
-intr_handler (struct intr_frame *args)
+intr_handler (struct intr_frame *frame)
{
bool external;
intr_handler_func *handler;
- external = args->vec_no >= 0x20 && args->vec_no < 0x30;
+ /* External interrupts are special.
+ We only handle one at a time (so interrupts must be off)
+ and they need to be acknowledged on the PIC (see below).
+ An external interrupt handler cannot sleep. */
+ external = frame->vec_no >= 0x20 && frame->vec_no < 0x30;
if (external)
{
ASSERT (intr_get_level () == INTR_OFF);
/* Invoke the interrupt's handler.
If there is no handler, invoke the unexpected interrupt
handler. */
- handler = intr_handlers[args->vec_no];
+ handler = intr_handlers[frame->vec_no];
if (handler == NULL)
- handler = panic;
- handler (args);
+ {
+ intr_dump_frame (frame);
+ PANIC ("Unexpected interrupt");
+ }
+ handler (frame);
/* Complete the processing of an external interrupt. */
if (external)
ASSERT (intr_context ());
in_external_intr = false;
- pic_end_of_interrupt (args->vec_no);
+ pic_end_of_interrupt (frame->vec_no);
if (yield_on_return)
thread_yield ();
}
}
-/* Handler for an interrupt that should not have been invoked. */
-static void
-panic (struct intr_frame *regs)
-{
- dump_intr_frame (regs);
- PANIC ("Panic!");
-}
-
-/* Handler for an exception (probably) caused by a user process. */
-static void
-kill (struct intr_frame *f)
-{
- /* This interrupt is one (probably) caused by a user process.
- For example, the process might have tried to access unmapped
- virtual memory (a page fault). For now, we simply kill the
- user process. Later, we'll want to handle page faults in
- the kernel. Real Unix-like operating systems pass most
- exceptions back to the process via signals, but we don't
- implement them. */
-
- /* The interrupt frame's code segment value tells us where the
- exception originated. */
- switch (f->cs)
- {
- case SEL_UCSEG:
- /* User's code segment, so it's a user exception, as we
- expected. */
- printk ("%s: dying due to interrupt %#04x (%s).\n",
- thread_name (thread_current ()),
- f->vec_no, intr_names[f->vec_no]);
- dump_intr_frame (f);
- thread_exit ();
-
- case SEL_KCSEG:
- /* Kernel's code segment, which indicates a kernel bug.
- Kernel code shouldn't throw exceptions. (Page faults
- may cause kernel exceptions--but they shouldn't arrive
- here.) */
- printk ("Kernel bug - unexpected interrupt in kernel\n");
- panic (f);
-
- default:
- /* Some other code segment? Shouldn't happen. */
- printk ("Interrupt %#04x (%s) in unknown segment %04x\n",
- f->vec_no, intr_names[f->vec_no], f->cs);
- thread_exit ();
- }
-}
-
/* Dumps interrupt frame F to the console, for debugging. */
-static void
-dump_intr_frame (struct intr_frame *f)
+void
+intr_dump_frame (const struct intr_frame *f)
{
- uint32_t cr2, ss;
+ uint32_t cr2;
+
+ /* Store current value of CR2 into `cr2'.
+ CR2 is the linear address of the last page fault.
+ See [IA32-v2a] "MOV--Move to/from Control Registers" and
+ [IA32-v3] 5.14 "Interrupt 14--Page Fault Exception
+ (#PF)". */
asm ("movl %%cr2, %0" : "=r" (cr2));
- asm ("movl %%ss, %0" : "=r" (ss));
- printk ("Interrupt %#04x (%s) at eip=%p\n",
+ printf ("Interrupt %#04x (%s) at eip=%p\n",
f->vec_no, intr_names[f->vec_no], f->eip);
- printk (" cr2=%08"PRIx32" error=%08"PRIx32"\n", cr2, f->error_code);
- printk (" eax=%08"PRIx32" ebx=%08"PRIx32" ecx=%08"PRIx32" edx=%08"PRIx32"\n",
+ printf (" cr2=%08"PRIx32" error=%08"PRIx32"\n", cr2, f->error_code);
+ printf (" eax=%08"PRIx32" ebx=%08"PRIx32" ecx=%08"PRIx32" edx=%08"PRIx32"\n",
f->eax, f->ebx, f->ecx, f->edx);
- printk (" esi=%08"PRIx32" edi=%08"PRIx32" esp=%08"PRIx32" ebp=%08"PRIx32"\n",
+ printf (" esi=%08"PRIx32" edi=%08"PRIx32" esp=%08"PRIx32" ebp=%08"PRIx32"\n",
f->esi, f->edi, (uint32_t) f->esp, f->ebp);
- printk (" cs=%04"PRIx16" ds=%04"PRIx16" es=%04"PRIx16" ss=%04"PRIx16"\n",
- f->cs, f->ds, f->es, f->cs != SEL_KCSEG ? f->ss : ss);
+ printf (" cs=%04"PRIx16" ds=%04"PRIx16" es=%04"PRIx16" ss=%04"PRIx16"\n",
+ f->cs, f->ds, f->es, f->ss);
}
+/* Returns the name of interrupt VEC. */
+const char *
+intr_name (uint8_t vec)
+{
+ return intr_names[vec];
+}
projects / pintos-anon / blobdiff