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Wait for IO on IRQ remap.

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This commit is contained in:
Dale Weiler 2015-05-20 23:08:58 -04:00
parent 5ddbbf8199
commit 6e1a594adc
2 changed files with 104 additions and 69 deletions
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159
kernel/cpu/irq.c
View File

@ -10,6 +10,71 @@
#include <system.h>
#include <logging.h>
/* Programmable interrupt controller */
#define PIC1 0x20
#define PIC1_COMMAND PIC1
#define PIC1_OFFSET 0x20
#define PIC1_DATA (PIC1+1)
#define PIC2 0xA0
#define PIC2_COMMAND PIC2
#define PIC2_OFFSET 0x28
#define PIC2_DATA (PIC2+1)
#define PIC_EOI 0x20
#define ICW1_ICW4 0x01
#define ICW1_INIT 0x10
#define PIC_WAIT() \
do { \
/* Port 0x80 is used for 'checkpoints' during POST */ \
asm volatile("outb %%al, $0x80" : : "a"(0)); \
} while (0)
/* Interrupts */
static volatile int sync_depth = 0;
#define SYNC_CLI() asm volatile("cli")
#define SYNC_STI() asm volatile("sti")
void int_disable(void) {
/* Check if interrupts are enabled */
uint32_t flags;
asm volatile("pushf\n\t"
"pop %%eax\n\t"
"movl %%eax, %0\n\t"
: "=r"(flags)
:
: "%eax");
/* Disable interrupts */
SYNC_CLI();
/* If interrupts were enabled, then this is the first call depth */
if (flags & (1 << 9)) {
sync_depth = 1;
} else {
/* Otherwise there is now an additional call depth */
sync_depth++;
}
}
void int_resume(void) {
/* If there is one or no call depths, reenable interrupts */
if (sync_depth == 0 || sync_depth == 1) {
SYNC_STI();
} else {
sync_depth--;
}
}
void int_enable(void) {
sync_depth = 0;
SYNC_STI();
}
/* Interrupt Requests */
extern void _irq0(void);
extern void _irq1(void);
extern void _irq2(void);
@ -35,9 +100,6 @@ static void (*irqs[])(void) = {
#define IRQ_CHAIN_SIZE (sizeof(irqs)/sizeof(*irqs))
#define IRQ_CHAIN_DEPTH 4
#define SYNC_CLI() asm volatile("cli")
#define SYNC_STI() asm volatile("sti")
static irq_handler_chain_t irq_routines[IRQ_CHAIN_SIZE * IRQ_CHAIN_DEPTH] = { NULL };
void irq_install_handler(size_t irq, irq_handler_chain_t handler) {
@ -52,7 +114,6 @@ void irq_install_handler(size_t irq, irq_handler_chain_t handler) {
SYNC_STI();
}
void irq_uninstall_handler(size_t irq) {
/* Disable interrupts when changing handlers */
SYNC_CLI();
@ -61,18 +122,26 @@ void irq_uninstall_handler(size_t irq) {
SYNC_STI();
}
static void irq_remap(void) {
/* Send EOI on each PIC just in case the boot loader messed up */
outportb(PIC1_COMMAND, PIC_EOI); PIC_WAIT();
outportb(PIC2_COMMAND, PIC_EOI); PIC_WAIT();
void irq_remap(void) {
outportb(0x20, 0x11);
outportb(0xA0, 0x11);
outportb(0x21, 0x20);
outportb(0xA1, 0x28);
outportb(0x21, 0x04);
outportb(0xA1, 0x02);
outportb(0x21, 0x01);
outportb(0xA1, 0x01);
outportb(0x21, 0x0);
outportb(0xA1, 0x0);
/* Cascade initialization */
outportb(PIC1_COMMAND, ICW1_INIT|ICW1_ICW4); PIC_WAIT();
outportb(PIC2_COMMAND, ICW1_INIT|ICW1_ICW4); PIC_WAIT();
/* Remap */
outportb(PIC1_DATA, PIC1_OFFSET); PIC_WAIT();
outportb(PIC2_DATA, PIC2_OFFSET); PIC_WAIT();
/* Cascade identity with slave PIC at IRQ2 */
outportb(PIC1_DATA, 0x04); PIC_WAIT();
outportb(PIC2_DATA, 0x02); PIC_WAIT();
/* Request 8086 mode on each PIC */
outportb(PIC1_DATA, 0x01); PIC_WAIT();
outportb(PIC2_DATA, 0x01); PIC_WAIT();
}
static void irq_setup_gates(void) {
@ -85,59 +154,25 @@ void irq_install(void) {
irq_setup_gates();
}
/* TODO: Clean up everything below */
void irq_ack(size_t irq_no) {
if (irq_no >= 8) {
outportb(0xA0, 0x20);
outportb(PIC2_COMMAND, PIC_EOI);
}
outportb(0x20, 0x20);
outportb(PIC1_COMMAND, PIC_EOI);
}
void irq_handler(struct regs *r) {
IRQ_OFF;
if (r->int_no > 47 || r->int_no < 32) {
IRQ_RES;
return;
}
for (size_t i = 0; i < IRQ_CHAIN_DEPTH; i++) {
irq_handler_chain_t handler = irq_routines[i * IRQ_CHAIN_SIZE + (r->int_no - 32)];
if (handler && handler(r)) {
goto _done;
/* Disable interrupts when handling */
SYNC_CLI();
if (r->int_no <= 47 && r->int_no >= 32) {
for (size_t i = 0; i < IRQ_CHAIN_DEPTH; i++) {
irq_handler_chain_t handler = irq_routines[i * IRQ_CHAIN_SIZE + (r->int_no - 32)];
if (handler && handler(r)) {
goto done;
}
}
irq_ack(r->int_no - 32);
}
irq_ack(r->int_no - 32);
_done:
IRQ_RES;
}
static int _irq_sem = 0;
void irq_off(void) {
uint32_t eflags;
asm volatile(
"pushf\n"
"pop %0\n"
"cli"
: "=r" (eflags));
if (eflags & (1 << 9)) {
_irq_sem = 1;
} else {
_irq_sem++;
}
}
void irq_res(void) {
if (_irq_sem == 0) {
asm volatile ("sti");
return;
}
_irq_sem--;
if (_irq_sem == 0) {
asm volatile ("sti");
}
}
void irq_on(void) {
_irq_sem = 0;
asm volatile ("sti");
done:
SYNC_STI();
}

14
kernel/include/system.h
View File

@ -15,15 +15,15 @@
#define asm __asm__
#define volatile __volatile__
extern unsigned int __irq_sem;
//extern unsigned int __irq_sem;
void irq_off(void);
void irq_res(void);
void irq_on(void);
void int_disable(void);
void int_resume(void);
void int_enable(void);
#define IRQ_OFF irq_off()
#define IRQ_RES irq_res()
#define IRQ_ON irq_on()
#define IRQ_OFF int_disable()
#define IRQ_RES int_resume()
#define IRQ_ON int_enable()
#define PAUSE { asm volatile ("hlt"); }
#define STOP while (1) { PAUSE; }