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fiq_debugger: tty write to tty fifo

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It means printf(user) write log to tty fifo, to reduce printf time.

Signed-off-by: Huibin Hong <huibin.hong@rock-chips.com>
Change-Id: Iaf55719e7089a7c3b3638e2976c97868eed3868e
This commit is contained in:
Huibin Hong
2023-06-20 09:57:49 +00:00
committed by Tao Huang
parent 6e3aaac428
commit eca6a53f7a
3 changed files with 129 additions and 22 deletions
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124
drivers/soc/rockchip/rk_fiq_debugger.c
View File

@ -229,22 +229,32 @@ static void debug_flush(struct platform_device *pdev)
#ifdef CONFIG_RK_CONSOLE_THREAD
#define FIFO_SIZE SZ_64K
#define LINE_MAX 1024
#define TTY_FIFO_SIZE SZ_64K
static DEFINE_KFIFO(fifo, unsigned char, FIFO_SIZE);
static char console_buf[LINE_MAX]; /* avoid FRAME WARN */
static bool console_thread_stop;
static DEFINE_KFIFO(tty_fifo, unsigned char, TTY_FIFO_SIZE);
static bool console_thread_stop; /* write on console_write */
static bool console_thread_running; /* write on console_thread */
static unsigned int console_dropped_messages;
static int write_room(struct platform_device *pdev)
{
return (TTY_FIFO_SIZE - kfifo_len(&tty_fifo));
}
static void console_putc(struct platform_device *pdev, unsigned int c)
{
struct rk_fiq_debugger *t;
unsigned int count = 500;
unsigned int count = 2; /* loop 2 times is enough */
unsigned long us = 400; /* the time to send 60 byte for baudrate 1500000 */
t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);
if (t->baudrate == 115200)
us = 5160; /* the time to send 60 byte for baudrate 115200 */
while (!(rk_fiq_read(t, UART_USR) & UART_USR_TX_FIFO_NOT_FULL) &&
count--)
usleep_range(200, 210);
usleep_range(us, us + us / 20);
rk_fiq_write(t, c, UART_TX);
}
@ -252,12 +262,16 @@ static void console_putc(struct platform_device *pdev, unsigned int c)
static void console_flush(struct platform_device *pdev)
{
struct rk_fiq_debugger *t;
unsigned int count = 500;
unsigned int count = 2; /* loop 2 times is enough */
unsigned long us = 428; /* the time to send 64 byte for baudrate 1500000 */
t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);
if (t->baudrate == 115200)
us = 5500; /* the time to send 64 byte for baudrate 115200 */
while (!(rk_fiq_read_lsr(t) & UART_LSR_TEMT) && count--)
usleep_range(200, 210);
usleep_range(us, us + us / 20);
}
static void console_put(struct platform_device *pdev,
@ -280,33 +294,79 @@ static void debug_put(struct platform_device *pdev,
}
}
static void wake_up_console_thread(struct task_struct *console_task)
{
/*
* Avoid dead lock on console_task->pi_lock and console_lock
* when call printk() in try_to_wake_up().
*
* cpu0 hold console_lock, then try lock pi_lock fail:
* printk()->vprintk_emit()->console_unlock()->try_to_wake_up()
* ->lock(pi_lock)->deadlock
*
* cpu1 hold pi_lock, then try lock console_lock fail:
* console_thread()->console_put()->usleep_range()->run_hrtimer()
* ->hrtimer_wakeup()->try_to_wake_up()[hold_pi_lock]->printk()
* ->vprintk_emit()->console_trylock_spining()->cpu_relax()->deadlock
*
* if cpu0 does not hold console_lock, cpu1 also deadlock on pi_lock:
* ...->hrtimer_wakeup()->try_to_wake_up()[hold_pi_lock]->printk()
* ->vprintk_emit()->console_unlock()->try_to_wake_up()
* ->lock(pi_lock)->deadlock
*
* so when console_task is running on usleep_range(), printk()
* should not wakeup console_task to avoid lock(pi_lock) again,
* as run_hrtimer() will wakeup console_task later.
* console_thread_running==false guarantee that console_task
* is not running on usleep_range().
*/
if (!READ_ONCE(console_thread_running))
wake_up_process(console_task);
}
static int console_thread(void *data)
{
struct platform_device *pdev = data;
char *buf = console_buf;
unsigned int len;
char buf[64], c = 0;
unsigned int len = 0, len_tty = 0;
while (1) {
unsigned int dropped;
set_current_state(TASK_INTERRUPTIBLE);
if (kfifo_is_empty(&fifo))
if (console_thread_stop || (kfifo_is_empty(&fifo) && kfifo_is_empty(&tty_fifo))) {
smp_store_mb(console_thread_running, false);
schedule();
smp_store_mb(console_thread_running, true);
}
if (kthread_should_stop())
break;
set_current_state(TASK_RUNNING);
while (!console_thread_stop) {
len = kfifo_out(&fifo, buf, LINE_MAX);
if (!len)
break;
console_put(pdev, buf, len);
while (!console_thread_stop && (!kfifo_is_empty(&fifo) || !kfifo_is_empty(&tty_fifo))) {
while (!console_thread_stop && kfifo_get(&fifo, &c)) {
console_put(pdev, &c, 1);
if (c == '\n')
break;
}
while (!console_thread_stop && kfifo_get(&tty_fifo, &c)) {
console_putc(pdev, c);
len_tty++;
if (c == '\n')
break;
}
}
if (len_tty > 0)
fiq_tty_wake_up(pdev);
len_tty = 0;
dropped = console_dropped_messages;
if (dropped && !console_thread_stop) {
console_dropped_messages = 0;
smp_wmb();
len = snprintf(buf, LINE_MAX,
"** %u console messages dropped **\n",
len = sprintf(buf, "** %u console messages dropped **\n",
dropped);
console_put(pdev, buf, len);
}
@ -342,18 +402,37 @@ static void console_write(struct platform_device *pdev, const char *s, unsigned
} else if (count) {
unsigned int ret = 0;
if (kfifo_len(&fifo) + count < FIFO_SIZE)
if (kfifo_len(&fifo) + count <= FIFO_SIZE)
ret = kfifo_in(&fifo, s, count);
if (!ret) {
console_dropped_messages++;
smp_wmb();
} else {
wake_up_process(t->console_task);
wake_up_console_thread(t->console_task);
}
}
}
#endif
static int tty_write(struct platform_device *pdev, const char *s, int count)
{
unsigned int ret = 0;
struct rk_fiq_debugger *t;
if (console_thread_stop)
return count;
t = container_of(dev_get_platdata(&pdev->dev), typeof(*t), pdata);
if (count > 0) {
if (kfifo_len(&tty_fifo) + count <= TTY_FIFO_SIZE)
ret = kfifo_in(&tty_fifo, s, count);
if (ret <= 0)
return 0;
wake_up_console_thread(t->console_task);
}
return count;
}
#endif
static void fiq_enable(struct platform_device *pdev, unsigned int irq, bool on)
{
@ -860,8 +939,11 @@ static void rk_serial_debug_init(void __iomem *base, phys_addr_t phy_base,
#ifdef CONFIG_RK_CONSOLE_THREAD
t->console_task = kthread_run(console_thread, pdev, "kconsole");
if (!IS_ERR(t->console_task))
if (!IS_ERR(t->console_task)) {
t->pdata.console_write = console_write;
t->pdata.tty_write = tty_write;
t->pdata.write_room = write_room;
}
#endif
pdev->name = "fiq_debugger";

24
drivers/staging/android/fiq_debugger/fiq_debugger.c
View File

@ -1164,6 +1164,15 @@ void fiq_tty_close(struct tty_struct *tty, struct file *filp)
tty_port_close(tty->port, tty, filp);
}
void fiq_tty_wake_up(struct platform_device *pdev)
{
struct fiq_debugger_state *state = platform_get_drvdata(pdev);
if (tty_port_initialized(&state->tty_port))
tty_port_tty_wakeup(&state->tty_port);
}
EXPORT_SYMBOL_GPL(fiq_tty_wake_up);
int fiq_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
int i;
@ -1174,6 +1183,11 @@ int fiq_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
if (!state->console_enable)
return count;
#ifdef CONFIG_RK_CONSOLE_THREAD
if (state->pdata->tty_write)
return state->pdata->tty_write(state->pdev, buf, count);
#endif
fiq_debugger_uart_enable(state);
spin_lock_irq(&state->console_lock);
for (i = 0; i < count; i++)
@ -1186,7 +1200,15 @@ int fiq_tty_write(struct tty_struct *tty, const unsigned char *buf, int count)
int fiq_tty_write_room(struct tty_struct *tty)
{
return 16;
#ifdef CONFIG_RK_CONSOLE_THREAD
int line = tty->index;
struct fiq_debugger_state **states = tty->driver->driver_state;
struct fiq_debugger_state *state = states[line];
if (state->pdata->write_room)
return state->pdata->write_room(state->pdev);
#endif
return 2048;
}
#ifdef CONFIG_CONSOLE_POLL

3
drivers/staging/android/fiq_debugger/fiq_debugger.h
View File

@ -63,6 +63,8 @@ struct fiq_debugger_pdata {
#ifdef CONFIG_RK_CONSOLE_THREAD
void (*console_write)(struct platform_device *pdev, const char *s,
unsigned int count);
int (*tty_write)(struct platform_device *pdev, const char *s, int count);
int (*write_room)(struct platform_device *pdev);
#endif
#ifdef CONFIG_FIQ_DEBUGGER_TRUST_ZONE
void (*switch_cpu)(struct platform_device *pdev, u32 cpu);
@ -70,4 +72,5 @@ struct fiq_debugger_pdata {
#endif
};
void fiq_tty_wake_up(struct platform_device *pdev);
#endif