Files
my-kern/kernel/fs/blockdev.c
2021-03-07 14:43:35 +01:00

118 lines
3.6 KiB
C

//
// Created by rick on 06-02-21.
//
#include <libc/libc.h>
#include <libk/libk.h>
#include <libc/kprintf.h>
#include <mem/malloc.h>
#include <tasks/task.h>
#include <tasks/locking.h>
#include <attributes.h>
#include <libc/sort.h>
#include "blockdev.h"
#define MAX_BLOCK_DEVS 64
int last_block_dev = 0;
block_device block_devices[MAX_BLOCK_DEVS] = {0};
extern struct block_dev_driver __start_block_dev_driver[];
extern struct block_dev_driver __stop_block_dev_driver[];
#define NUM_DRIVERS ((size_t)(__stop_block_dev_driver - __start_block_dev_driver))
#define DRIVER(i) ((__start_block_dev_driver) + (i))
semaphore_t *block_semaphore;
bool blockdev_task_running = false;
uint8_t block_dev_register(block_device *device) {
if (last_block_dev >= MAX_BLOCK_DEVS - 1) {
return BLOCK_DEV_REGISTER_FULL;
}
memcpy((uint8_t *) &block_devices[last_block_dev++], (const uint8_t *) device, sizeof(block_device));
if (blockdev_task_running) {
semaphore_signal(block_semaphore);
}
return BLOCK_DEV_REGISTER_OK;
}
void block_dev_free(block_device *device) {
//todo
k_panics("block dev free not supported");
}
int block_dev_num_not_scanned() {
int not_scanned = 0;
for (int i = 0; i < last_block_dev; ++i) {
if (block_devices[i].flags.present && !block_devices[i].flags.scanned) not_scanned++;
}
return not_scanned;
}
void block_dev_scan() {
int c_last_block_dev = last_block_dev;
for (int i = 0; i < c_last_block_dev; ++i) {
if (block_devices[i].flags.scanned || !block_devices[i].flags.present) continue;
uint8_t *lba0 = malloc(block_devices[i].block_size);
uint8_t read_result = block_devices[i].access(&block_devices[i], BLOCK_DEV_DIRECTION_READ, 0, 1, lba0);
if (read_result != BLOCK_DEV_ACCESS_OK) {
block_devices[i].flags.unreadable = 1;
goto _block_dev_scan_free;
}
for (size_t j = 0; j < NUM_DRIVERS; ++j) {
// validate if driver is appropriate at all
// don't use a root device driver (i.e. mbr) for a non-root device
if (DRIVER(j)->flags.root_only && !block_devices[i].flags.root_device) continue;
// let the driver test the disk
uint8_t driver_result = DRIVER(j)->check_device(&block_devices[i], lba0);
if (driver_result == BLOCK_DEV_DRIVER_CHECK_OK) {
block_devices[i].driver = DRIVER(j);
block_devices[i].flags.driver_installed = 1;
break;
}
}
_block_dev_scan_free:
free(lba0);
block_devices[i].flags.scanned = 1;
}
}
int block_dev_driver_comp(const void *a, const void *b) {
int rank_a = ((struct block_dev_driver *) a)->rank;
int rank_b = ((struct block_dev_driver *) b)->rank;
if (rank_a > rank_b) {
return 1;
} else if (rank_a < rank_b) {
return -1;
}
return 0;
}
void block_dev_pre_init() {
qsort(DRIVER(0), NUM_DRIVERS, sizeof(struct block_dev_driver), block_dev_driver_comp);
}
void noreturn block_dev_task(void *data) {
while (true) {
semaphore_wait(block_semaphore);
block_dev_scan();
}
}
void block_dev_start_task() {
block_semaphore = semaphore_create(1);
blockdev_task_running = true;
task_spawn(block_dev_task, NULL);
}
void block_dev_print_info() {
printf("Block devices:\n");
for (int i = 0; i < last_block_dev; ++i) {
printf("-%s driver: %s\n",
block_devices[i].identifier,
block_devices[i].flags.driver_installed ? block_devices[i].driver->name : "n/a");
}
}