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- /*
- * irq.c
- *
- * Copyright (C) 2013 Aleksandar Andrejevic <theflash@sdf.lonestar.org>
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as
- * published by the Free Software Foundation, either version 3 of the
- * License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
- #include <irq.h>
- #include <heap.h>
- #include <lock.h>
- #include <cpu.h>
- static list_entry_t irq_handlers[MAX_IRQ_COUNT];
- static dword_t irq_alloc_bitmap = 0xFFFFF3FF;
- static byte_t primary_pic_mask = 0xFF, secondary_pic_mask = 0xFF;
- static void irq_handler(registers_t *regs, byte_t int_num)
- {
- irq_handler_t *handler;
- byte_t irq_num = int_num - IRQ_INT_BASE;
- if (irq_num == 7)
- {
- cpu_write_port_byte(PRIMARY_PIC_CMD, 0x0B);
- byte_t isr = cpu_read_port_byte(PRIMARY_PIC_CMD);
- if (!(isr & 0x80)) return;
- }
- if (irq_num == 15)
- {
- cpu_write_port_byte(SECONDARY_PIC_CMD, 0x0B);
- byte_t isr = cpu_read_port_byte(SECONDARY_PIC_CMD);
- if (!(isr & 0x80))
- {
- cpu_write_port_byte(PRIMARY_PIC_CMD, 0x20);
- return;
- }
- }
- list_entry_t *ptr;
- for (ptr = irq_handlers[irq_num].next; ptr != &irq_handlers[irq_num]; ptr = ptr->next)
- {
- handler = CONTAINER_OF(ptr, irq_handler_t, list);
- cpu_enable_interrupts();
- handler->procedure(regs, irq_num);
- cpu_disable_interrupts();
- }
- if (irq_num >= 8) cpu_write_port_byte(SECONDARY_PIC_CMD, 0x20);
- cpu_write_port_byte(PRIMARY_PIC_CMD, 0x20);
- }
- dword_t register_irq_handler(byte_t irq_num, irq_handler_proc_t handler_proc, bool_t exclusive)
- {
- dword_t ret = ERR_SUCCESS;
- critical_t critical;
- if (irq_num >= MAX_IRQ_COUNT) return ERR_INVALID;
- irq_handler_t *handler = (irq_handler_t*)malloc(sizeof(irq_handler_t));
- if (handler == NULL) return ERR_NOMEMORY;
- handler->procedure = handler_proc;
- handler->exclusive = exclusive;
- enter_critical(&critical);
- if (irq_handlers[irq_num].next == &irq_handlers[irq_num])
- {
- if (irq_num >= 0 && irq_num < 8)
- {
- primary_pic_mask &= ~(1 << irq_num);
- cpu_write_port_byte(PRIMARY_PIC_DATA, primary_pic_mask);
- }
- else
- {
- secondary_pic_mask &= ~(1 << (irq_num - 8));
- cpu_write_port_byte(SECONDARY_PIC_DATA, secondary_pic_mask);
- }
- }
- else if (exclusive || CONTAINER_OF(irq_handlers[irq_num].next, irq_handler_t, list)->exclusive)
- {
- ret = ERR_EXISTS;
- }
- if (ret == ERR_SUCCESS) list_append(&irq_handlers[irq_num], &handler->list);
- leave_critical(&critical);
- return ret;
- }
- dword_t unregister_irq_handler(byte_t irq_num, irq_handler_proc_t handler_proc)
- {
- bool_t found = FALSE;
- critical_t critical;
- if (irq_num >= MAX_IRQ_COUNT) return ERR_INVALID;
- enter_critical(&critical);
- list_entry_t *ptr;
- for (ptr = irq_handlers[irq_num].next; ptr != &irq_handlers[irq_num]; ptr = ptr->next)
- {
- irq_handler_t *handler = CONTAINER_OF(ptr, irq_handler_t, list);
- if (handler->procedure == handler_proc)
- {
- list_remove(&handler->list);
- free(handler);
- found = TRUE;
- break;
- }
- }
- leave_critical(&critical);
- return found ? ERR_SUCCESS : ERR_NOTFOUND;
- }
- byte_t alloc_irq()
- {
- byte_t i;
- for (i = 0; i < MAX_IRQ_COUNT; i++) if (!test_bit(&irq_alloc_bitmap, i))
- {
- set_bit(&irq_alloc_bitmap, i);
- return i;
- }
- return 0xFF;
- }
- void free_irq(byte_t number)
- {
- clear_bit(&irq_alloc_bitmap, number);
- }
- void irq_init()
- {
- byte_t i;
- primary_pic_mask &= ~(1 << PRIMARY_PIC_CASCADE_IRQ);
- cpu_write_port_byte(PRIMARY_PIC_CMD, 0x11);
- cpu_write_port_byte(SECONDARY_PIC_CMD, 0x11);
- cpu_write_port_byte(PRIMARY_PIC_DATA, PRIMARY_IRQ_INT);
- cpu_write_port_byte(SECONDARY_PIC_DATA, SECONDARY_IRQ_INT);
- cpu_write_port_byte(PRIMARY_PIC_DATA, 1 << PRIMARY_PIC_CASCADE_IRQ);
- cpu_write_port_byte(SECONDARY_PIC_DATA, 1 << SECONDARY_PIC_CASCADE_IRQ);
- cpu_write_port_byte(PRIMARY_PIC_DATA, PIC_8086_MODE);
- cpu_write_port_byte(SECONDARY_PIC_DATA, PIC_8086_MODE);
- cpu_write_port_byte(PRIMARY_PIC_DATA, primary_pic_mask);
- cpu_write_port_byte(SECONDARY_PIC_DATA, secondary_pic_mask);
- for (i = 0; i < MAX_IRQ_COUNT; i++)
- {
- list_init(&irq_handlers[i]);
- set_int_handler(IRQ_INT_BASE + i, irq_handler, FALSE, FALSE);
- }
- }
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