#include <lunaix/timer.h>
#include <lunaix/common.h>
#include <lunaix/syslog.h>
-#include <lunaix/mm/kalloc.h>
-
-#include <hal/cpu.h>
+#include <hal/acpi/acpi.h>
#include <hal/ioapic.h>
+#include <hal/cpu.h>
#include <arch/x86/interrupts.h>
-#include <stdint.h>
#include <klibc/string.h>
+#include <stdint.h>
+
#define PS2_DEV_CMD_MAX_ATTEMPTS 5
LOG_MODULE("PS2KBD");
};
-#define KBD_STATE_WAIT_KEY 0
-#define KBD_STATE_SPECIAL 1
-#define KBD_STATE_RELEASED 2
+#define KBD_STATE_KWAIT 0x00
+#define KBD_STATE_KSPECIAL 0x01
+#define KBD_STATE_KRELEASED 0x02
+#define KBD_STATE_CMDPROCS 0x40
void intr_ps2_kbd_handler(const isr_param* param);
+static struct kdb_keyinfo_pkt* ps2_keybuffer_next_write();
+// TODO: Abstract the bounded buffer out.
void ps2_device_post_cmd(char cmd, char arg) {
- // 不需要任何的类似lock cmpxchgl的骚操作。
- // 这条赋值表达式最多涉及一个内存引用（e.g., movl $1, (cmd_q.lock)），因此是原子的。
- cmd_q.lock = 1;
+ mutex_lock(&cmd_q.mutex);
int index = (cmd_q.queue_ptr + cmd_q.queue_len) % PS2_CMD_QUEUE_SIZE;
- int diff = index - cmd_q.queue_ptr;
- if (diff > 0 && diff != cmd_q.queue_len) {
+ if (index == cmd_q.queue_ptr && cmd_q.queue_len) {
// 队列已满！
+ mutex_unlock(&cmd_q.mutex);
return;
}
cmd_q.queue_len++;
// 释放锁，同理。
- cmd_q.lock = 0;
+ mutex_unlock(&cmd_q.mutex);
}
void ps2_kbd_init() {
memset(&cmd_q, 0, sizeof(cmd_q));
memset(&key_buf, 0, sizeof(key_buf));
memset(&kbd_state, 0, sizeof(kbd_state));
- kbd_state.translation_table = scancode_set2;
- kbd_state.state = KBD_STATE_WAIT_KEY;
+
+ mutex_init(&cmd_q.mutex);
+ mutex_init(&key_buf.mutex);
- cpu_disable_interrupt();
- // XXX: 是否需要使用FADT探测PS/2控制器的存在？
+ kbd_state.translation_table = scancode_set2;
+ kbd_state.state = KBD_STATE_KWAIT;
+
+ acpi_context* acpi_ctx = acpi_get_context();
+ if (acpi_ctx->fadt.header.rev > 1) {
+ /*
+ * 只有当前ACPI版本大于1时，我们才使用FADT的IAPC_BOOT_ARCH去判断8042是否存在。
+ * 这是一个坑，在ACPI v1中，这个字段是reserved！而这及至APCI v2才出现。
+ * 需要注意：Bochs 和 QEMU 使用的是ACPI v1，而非 v2 （virtualbox好像是v4）
+ *
+ * 请看Bochs的bios源码（QEMU的BIOS其实是照抄bochs的，所以也是一个德行。。）：
+ * https://bochs.sourceforge.io/cgi-bin/lxr/source/bios/rombios32.c#L1314
+ */
+ if (!(acpi_ctx->fadt.boot_arch & IAPC_ARCH_8042)) {
+ kprintf(KERROR "No PS/2 controller detected.\n");
+ // FUTURE: Some alternative fallback on this? Check PCI bus for USB controller instead?
+ return;
+ }
+ }
+ else {
+ kprintf(KWARN "Outdated FADT used, assuming 8042 always exist.\n");
+ }
+
+
+ cpu_disable_interrupt();
// 1、禁用任何的PS/2设备
ps2_post_cmd(PS2_PORT_CTRL_CMDREG, PS2_CMD_PORT1_DISABLE, PS2_NO_ARG);
// 因为我们需要保证isr尽量的简短，运行起来快速。而发送这些命令非常的耗时。
timer_run_ms(5, ps2_process_cmd, NULL, TIMER_MODE_PERIODIC);
+ /*
+ * 一切准备就绪后，我们才教ioapic去启用IRQ#1。
+ * 至于为什么要在这里，原因是：初始化所使用的一些指令可能会导致IRQ#1的触发（因为返回码），或者是一些什么
+ * 情况导致IRQ#1的误触发（可能是未初始化导致IRQ#1线上不稳定）。于是这些IRQ#1会堆积在APIC的队列里（因为此时我们正在
+ * 初始化8042，屏蔽了所有中断，IF=0）。
+ * 当sti后，这些堆积的中断会紧跟着递送进CPU里，导致我们的键盘handler误认为由按键按下，从而将这个毫无意义的数值加入
+ * 我们的队列中，以供上层读取。
+ *
+ * 所以，保险的方法是：在初始化后才去设置ioapic，这样一来我们就能有一个稳定的IRQ#1以放心使用。
+ */
+ uint8_t irq_kbd = ioapic_get_irq(acpi_ctx, PC_AT_IRQ_KBD);
+ ioapic_redirect(irq_kbd, PC_KBD_IV, 0, IOAPIC_DELMOD_FIXED);
+
done:
cpu_enable_interrupt();
}
// 因此，我们这里仅仅进行判断。
// 会不会产生指令堆积？不会，因为指令发送的频率远远低于指令队列清空的频率。在目前，我们发送的唯一指令
// 就只是用来开关键盘上的LED灯（如CAPSLOCK）。
- if (!cmd_q.queue_len || cmd_q.lock) {
+ if (mutex_on_hold(&cmd_q.mutex) || !cmd_q.queue_len) {
return;
}
-
+
// 处理队列排头的指令
struct ps2_cmd *pending_cmd = &cmd_q.cmd_queue[cmd_q.queue_ptr];
char result;
// 则尝试最多五次
do {
result = ps2_issue_dev_cmd(pending_cmd->cmd, pending_cmd->arg);
+ kbd_state.state += KBD_STATE_CMDPROCS;
attempts++;
} while(result == PS2_RESULT_NAK && attempts < PS2_DEV_CMD_MAX_ATTEMPTS);
cmd_q.queue_len--;
}
-static struct kdb_keyinfo_pkt* ps2_keybuffer_next_write() {
- int index = (key_buf.read_ptr + key_buf.buffered_len) % PS2_KBD_RECV_BUFFER_SIZE;
- if (index == key_buf.read_ptr && key_buf.buffered_len) {
- // the reader lagged so much. It is suggested to read from beginning.
- key_buf.read_ptr = 0;
- key_buf.buffered_len = index;
- }
- else {
- key_buf.buffered_len++;
- }
- return &key_buf.buffer[index];
-}
-
void kbd_buffer_key_event(kbd_keycode_t key, uint8_t scancode, kbd_kstate_t state) {
// forgive me on these ugly bit-level tricks,
// I really hate doing branching on these "fliping switch" things
}
state = state | kbd_state.key_state;
key = key & (0xffdf | -('a' > key || key > 'z' || !(state & KBD_KEY_FCAPSLKED)));
- time_t timestamp = clock_systime();
- // TODO: Construct the packet.
- if (!key_buf.lock) {
+
+ if (!mutex_on_hold(&key_buf.mutex)) {
struct kdb_keyinfo_pkt* keyevent_pkt = ps2_keybuffer_next_write();
- keyevent_pkt->keycode = key;
- keyevent_pkt->scancode = scancode;
- keyevent_pkt->state = state;
- keyevent_pkt->timestamp = timestamp;
+ *keyevent_pkt = (struct kdb_keyinfo_pkt) {
+ .keycode = key,
+ .scancode = scancode,
+ .state = state,
+ .timestamp = clock_systime()
+ };
}
// kprintf(KDEBUG "%c (t=%d, s=%x, c=%d)\n", key & 0x00ff, timestamp, state, key >> 8);
}
void intr_ps2_kbd_handler(const isr_param* param) {
- uint8_t scancode = io_inb(PS2_PORT_ENC_DATA) & 0xff;
+
+ // Do not move this line. It is in the right place and right order.
+ // This is to ensure we've cleared the output buffer everytime, so it won't pile up across irqs.
+ uint8_t scancode = io_inb(PS2_PORT_ENC_DATA);
kbd_keycode_t key;
- // 用于区分0xfe,0xfa等指令返回码。
- if (scancode >= 0xFA) {
+ /*
+ * 判断键盘是否处在指令发送状态，防止误触发。（伪输入中断）
+ * 这是因为我们需要向ps/2设备发送指令（比如控制led灯），而指令会有返回码。
+ * 这就会有可能导致ps/2控制器在受到我们的命令后（在ps2_process_cmd中），
+ * 产生IRQ#1中断（虽然说这种情况取决于底层BIOS实现，但还是会发生，比如QEMU和bochs）。
+ * 所以这就是说，当IRQ#1中断产生时，我们的CPU正处在另一个ISR中。这样就会导致所有的外部中断被缓存在APIC内部的
+ * FIFO队列里，进行排队等待（APIC长度为二的队列 {IRR, TMR}；参考 Intel Manual Vol.3A 10.8.4）
+ * 那么当ps2_process_cmd执行完后（内嵌在#APIC_TIMER_IV），CPU返回EOI给APIC，APIC紧接着将排在队里的IRQ#1发送给CPU
+ * 造成误触发。也就是说，我们此时读入的scancode实则上是上一个指令的返回代码。
+ *
+ * Problem 1 (Fixed):
+ * 但是这种方法有个问题，那就是，假若我们的某一个命令失败了一次，ps/2给出0xfe，我们重传，ps/2收到指令并给出0xfa。
+ * 那么这样一来，将会由两个连续的IRQ#1产生。而APIC是最多可以缓存两个IRQ，于是我们就会漏掉一个IRQ，依然会误触发。
+ * Solution:
+ * 累加掩码 ;)
+ */
+ if ((kbd_state.state & 0xc0)) {
+ kbd_state.state -= KBD_STATE_CMDPROCS;
return;
}
- //kprintf(KINFO "%x\n", scancode & 0xff);
+ //kprintf(KDEBUG "%x\n", scancode & 0xff);
switch (kbd_state.state)
{
- case KBD_STATE_WAIT_KEY:
+ case KBD_STATE_KWAIT:
if (scancode == 0xf0) { // release code
- kbd_state.state = KBD_STATE_RELEASED;
+ kbd_state.state = KBD_STATE_KRELEASED;
} else if (scancode == 0xe0) {
- kbd_state.state = KBD_STATE_SPECIAL;
+ kbd_state.state = KBD_STATE_KSPECIAL;
kbd_state.translation_table = scancode_set2_ex;
} else {
key = kbd_state.translation_table[scancode];
kbd_buffer_key_event(key, scancode, KBD_KEY_FPRESSED);
}
break;
- case KBD_STATE_SPECIAL:
+ case KBD_STATE_KSPECIAL:
if (scancode == 0xf0) { //release code
- kbd_state.state = KBD_STATE_RELEASED;
+ kbd_state.state = KBD_STATE_KRELEASED;
} else {
key = kbd_state.translation_table[scancode];
kbd_buffer_key_event(key, scancode, KBD_KEY_FPRESSED);
- kbd_state.state = KBD_STATE_WAIT_KEY;
+ kbd_state.state = KBD_STATE_KWAIT;
kbd_state.translation_table = scancode_set2;
}
break;
- case KBD_STATE_RELEASED:
+ case KBD_STATE_KRELEASED:
key = kbd_state.translation_table[scancode];
kbd_buffer_key_event(key, scancode, KBD_KEY_FRELEASED);
// reset the translation table to scancode_set2
- kbd_state.state = KBD_STATE_WAIT_KEY;
+ kbd_state.state = KBD_STATE_KWAIT;
kbd_state.translation_table = scancode_set2;
break;
while((result = io_inb(PS2_PORT_CTRL_STATUS)) & PS2_STATUS_IFULL);
io_outb(port, cmd);
+ io_delay(PS2_DELAY);
+
if (!(arg & PS2_NO_ARG)) {
// 所有参数一律通过0x60传入。
io_outb(PS2_PORT_ENC_CMDREG, (uint8_t)(arg & 0x00ff));
+ io_delay(PS2_DELAY);
}
}
-struct kdb_keyinfo_pkt* kbd_try_read_one() {
+int kbd_recv_key(struct kdb_keyinfo_pkt* key_event) {
if (!key_buf.buffered_len) {
- return NULL;
+ return 0;
}
- key_buf.lock = 1;
- struct kdb_keyinfo_pkt* pkt_copy =
- (struct kdb_keyinfo_pkt*) lxmalloc(sizeof(struct kdb_keyinfo_pkt));
+ mutex_lock(&key_buf.mutex);
struct kdb_keyinfo_pkt* pkt_current = &key_buf.buffer[key_buf.read_ptr];
- pkt_copy->keycode = pkt_current->keycode;
- pkt_copy->scancode = pkt_current->scancode;
- pkt_copy->state = pkt_current->state;
- pkt_copy->timestamp = pkt_current->timestamp;
+ *key_event = *pkt_current;
key_buf.buffered_len--;
key_buf.read_ptr = (key_buf.read_ptr + 1) % PS2_KBD_RECV_BUFFER_SIZE;
- key_buf.lock = 0;
- return pkt_copy;
+ mutex_unlock(&key_buf.mutex);
+ return 1;
+}
+
+static struct kdb_keyinfo_pkt* ps2_keybuffer_next_write() {
+ int index = (key_buf.read_ptr + key_buf.buffered_len) % PS2_KBD_RECV_BUFFER_SIZE;
+ if (index == key_buf.read_ptr && key_buf.buffered_len) {
+ // the reader is lagged so much such that the buffer is full.
+ // It is suggested to read from beginning for nearly up-to-date readings.
+ key_buf.read_ptr = 0;
+ key_buf.buffered_len = index;
+ }
+ else {
+ key_buf.buffered_len++;
+ }
+ return &key_buf.buffer[index];
}
\ No newline at end of file
git://scm.lunaixsky.com / lunaix-os.git / blobdiff