diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/tty/serial/8250/8250_early.c | 23 | ||||
| -rw-r--r-- | drivers/tty/serial/amba-pl011.c | 32 | ||||
| -rw-r--r-- | drivers/tty/serial/kgdboc.c | 318 | ||||
| -rw-r--r-- | drivers/tty/serial/qcom_geni_serial.c | 32 |
4 files changed, 374 insertions, 31 deletions
diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c index 5cd8c36c8fcc..70d7826788f5 100644 --- a/drivers/tty/serial/8250/8250_early.c +++ b/drivers/tty/serial/8250/8250_early.c @@ -109,6 +109,28 @@ static void early_serial8250_write(struct console *console, uart_console_write(port, s, count, serial_putc); } +#ifdef CONFIG_CONSOLE_POLL +static int early_serial8250_read(struct console *console, + char *s, unsigned int count) +{ + struct earlycon_device *device = console->data; + struct uart_port *port = &device->port; + unsigned int status; + int num_read = 0; + + while (num_read < count) { + status = serial8250_early_in(port, UART_LSR); + if (!(status & UART_LSR_DR)) + break; + s[num_read++] = serial8250_early_in(port, UART_RX); + } + + return num_read; +} +#else +#define early_serial8250_read NULL +#endif + static void __init init_port(struct earlycon_device *device) { struct uart_port *port = &device->port; @@ -149,6 +171,7 @@ int __init early_serial8250_setup(struct earlycon_device *device, init_port(device); device->con->write = early_serial8250_write; + device->con->read = early_serial8250_read; return 0; } EARLYCON_DECLARE(uart8250, early_serial8250_setup); diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c index 2296bb0f9578..c010f639298d 100644 --- a/drivers/tty/serial/amba-pl011.c +++ b/drivers/tty/serial/amba-pl011.c @@ -2435,6 +2435,37 @@ static void pl011_early_write(struct console *con, const char *s, unsigned n) uart_console_write(&dev->port, s, n, pl011_putc); } +#ifdef CONFIG_CONSOLE_POLL +static int pl011_getc(struct uart_port *port) +{ + if (readl(port->membase + UART01x_FR) & UART01x_FR_RXFE) + return NO_POLL_CHAR; + + if (port->iotype == UPIO_MEM32) + return readl(port->membase + UART01x_DR); + else + return readb(port->membase + UART01x_DR); +} + +static int pl011_early_read(struct console *con, char *s, unsigned int n) +{ + struct earlycon_device *dev = con->data; + int ch, num_read = 0; + + while (num_read < n) { + ch = pl011_getc(&dev->port); + if (ch == NO_POLL_CHAR) + break; + + s[num_read++] = ch; + } + + return num_read; +} +#else +#define pl011_early_read NULL +#endif + /* * On non-ACPI systems, earlycon is enabled by specifying * "earlycon=pl011,<address>" on the kernel command line. @@ -2454,6 +2485,7 @@ static int __init pl011_early_console_setup(struct earlycon_device *device, return -ENODEV; device->con->write = pl011_early_write; + device->con->read = pl011_early_read; return 0; } diff --git a/drivers/tty/serial/kgdboc.c b/drivers/tty/serial/kgdboc.c index c9f94fa82be4..41396982e9e0 100644 --- a/drivers/tty/serial/kgdboc.c +++ b/drivers/tty/serial/kgdboc.c @@ -20,6 +20,8 @@ #include <linux/vt_kern.h> #include <linux/input.h> #include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/serial_core.h> #define MAX_CONFIG_LEN 40 @@ -27,6 +29,7 @@ static struct kgdb_io kgdboc_io_ops; /* -1 = init not run yet, 0 = unconfigured, 1 = configured. */ static int configured = -1; +static DEFINE_MUTEX(config_mutex); static char config[MAX_CONFIG_LEN]; static struct kparam_string kps = { @@ -38,6 +41,14 @@ static int kgdboc_use_kms; /* 1 if we use kernel mode switching */ static struct tty_driver *kgdb_tty_driver; static int kgdb_tty_line; +static struct platform_device *kgdboc_pdev; + +#if IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) +static struct kgdb_io kgdboc_earlycon_io_ops; +static struct console *earlycon; +static int (*earlycon_orig_exit)(struct console *con); +#endif /* IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */ + #ifdef CONFIG_KDB_KEYBOARD static int kgdboc_reset_connect(struct input_handler *handler, struct input_dev *dev, @@ -131,13 +142,27 @@ static void kgdboc_unregister_kbd(void) #define kgdboc_restore_input() #endif /* ! CONFIG_KDB_KEYBOARD */ +#if IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) +static void cleanup_earlycon(void) +{ + if (earlycon) + kgdb_unregister_io_module(&kgdboc_earlycon_io_ops); +} +#else /* !IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */ +static inline void cleanup_earlycon(void) { } +#endif /* !IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */ + static void cleanup_kgdboc(void) { + cleanup_earlycon(); + + if (configured != 1) + return; + if (kgdb_unregister_nmi_console()) return; kgdboc_unregister_kbd(); - if (configured == 1) - kgdb_unregister_io_module(&kgdboc_io_ops); + kgdb_unregister_io_module(&kgdboc_io_ops); } static int configure_kgdboc(void) @@ -198,20 +223,79 @@ nmi_con_failed: kgdb_unregister_io_module(&kgdboc_io_ops); noconfig: kgdboc_unregister_kbd(); - config[0] = 0; configured = 0; - cleanup_kgdboc(); return err; } +static int kgdboc_probe(struct platform_device *pdev) +{ + int ret = 0; + + mutex_lock(&config_mutex); + if (configured != 1) { + ret = configure_kgdboc(); + + /* Convert "no device" to "defer" so we'll keep trying */ + if (ret == -ENODEV) + ret = -EPROBE_DEFER; + } + mutex_unlock(&config_mutex); + + return ret; +} + +static struct platform_driver kgdboc_platform_driver = { + .probe = kgdboc_probe, + .driver = { + .name = "kgdboc", + .suppress_bind_attrs = true, + }, +}; + static int __init init_kgdboc(void) { - /* Already configured? */ - if (configured == 1) + int ret; + + /* + * kgdboc is a little bit of an odd "platform_driver". It can be + * up and running long before the platform_driver object is + * created and thus doesn't actually store anything in it. There's + * only one instance of kgdb so anything is stored as global state. + * The platform_driver is only created so that we can leverage the + * kernel's mechanisms (like -EPROBE_DEFER) to call us when our + * underlying tty is ready. Here we init our platform driver and + * then create the single kgdboc instance. + */ + ret = platform_driver_register(&kgdboc_platform_driver); + if (ret) + return ret; + + kgdboc_pdev = platform_device_alloc("kgdboc", PLATFORM_DEVID_NONE); + if (!kgdboc_pdev) { + ret = -ENOMEM; + goto err_did_register; + } + + ret = platform_device_add(kgdboc_pdev); + if (!ret) return 0; - return configure_kgdboc(); + platform_device_put(kgdboc_pdev); + +err_did_register: + platform_driver_unregister(&kgdboc_platform_driver); + return ret; +} + +static void exit_kgdboc(void) +{ + mutex_lock(&config_mutex); + cleanup_kgdboc(); + mutex_unlock(&config_mutex); + + platform_device_unregister(kgdboc_pdev); + platform_driver_unregister(&kgdboc_platform_driver); } static int kgdboc_get_char(void) @@ -234,24 +318,20 @@ static int param_set_kgdboc_var(const char *kmessage, const struct kernel_param *kp) { size_t len = strlen(kmessage); + int ret = 0; if (len >= MAX_CONFIG_LEN) { pr_err("config string too long\n"); return -ENOSPC; } - /* Only copy in the string if the init function has not run yet */ - if (configured < 0) { - strcpy(config, kmessage); - return 0; - } - if (kgdb_connected) { pr_err("Cannot reconfigure while KGDB is connected.\n"); - return -EBUSY; } + mutex_lock(&config_mutex); + strcpy(config, kmessage); /* Chop out \n char as a result of echo */ if (len && config[len - 1] == '\n') @@ -260,8 +340,30 @@ static int param_set_kgdboc_var(const char *kmessage, if (configured == 1) cleanup_kgdboc(); - /* Go and configure with the new params. */ - return configure_kgdboc(); + /* + * Configure with the new params as long as init already ran. + * Note that we can get called before init if someone loads us + * with "modprobe kgdboc kgdboc=..." or if they happen to use the + * the odd syntax of "kgdboc.kgdboc=..." on the kernel command. + */ + if (configured >= 0) + ret = configure_kgdboc(); + + /* + * If we couldn't configure then clear out the config. Note that + * specifying an invalid config on the kernel command line vs. + * through sysfs have slightly different behaviors. If we fail + * to configure what was specified on the kernel command line + * we'll leave it in the 'config' and return -EPROBE_DEFER from + * our probe. When specified through sysfs userspace is + * responsible for loading the tty driver before setting up. + */ + if (ret) + config[0] = '\0'; + + mutex_unlock(&config_mutex); + + return ret; } static int dbg_restore_graphics; @@ -275,14 +377,10 @@ static void kgdboc_pre_exp_handler(void) /* Increment the module count when the debugger is active */ if (!kgdb_connected) try_module_get(THIS_MODULE); - - atomic_inc(&ignore_console_lock_warning); } static void kgdboc_post_exp_handler(void) { - atomic_dec(&ignore_console_lock_warning); - /* decrement the module count when the debugger detaches */ if (!kgdb_connected) module_put(THIS_MODULE); @@ -301,7 +399,7 @@ static struct kgdb_io kgdboc_io_ops = { .post_exception = kgdboc_post_exp_handler, }; -#ifdef CONFIG_KGDB_SERIAL_CONSOLE +#if IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) static int kgdboc_option_setup(char *opt) { if (!opt) { @@ -324,23 +422,181 @@ __setup("kgdboc=", kgdboc_option_setup); /* This is only available if kgdboc is a built in for early debugging */ static int __init kgdboc_early_init(char *opt) { - /* save the first character of the config string because the - * init routine can destroy it. - */ - char save_ch; - kgdboc_option_setup(opt); - save_ch = config[0]; - init_kgdboc(); - config[0] = save_ch; + configure_kgdboc(); return 0; } early_param("ekgdboc", kgdboc_early_init); -#endif /* CONFIG_KGDB_SERIAL_CONSOLE */ + +static int kgdboc_earlycon_get_char(void) +{ + char c; + + if (!earlycon->read(earlycon, &c, 1)) + return NO_POLL_CHAR; + + return c; +} + +static void kgdboc_earlycon_put_char(u8 chr) +{ + earlycon->write(earlycon, &chr, 1); +} + +static void kgdboc_earlycon_pre_exp_handler(void) +{ + struct console *con; + static bool already_warned; + + if (already_warned) + return; + + /* + * When the first normal console comes up the kernel will take all + * the boot consoles out of the list. Really, we should stop using + * the boot console when it does that but until a TTY is registered + * we have no other choice so we keep using it. Since not all + * serial drivers might be OK with this, print a warning once per + * boot if we detect this case. + */ + for_each_console(con) + if (con == earlycon) + return; + + already_warned = true; + pr_warn("kgdboc_earlycon is still using bootconsole\n"); +} + +static int kgdboc_earlycon_deferred_exit(struct console *con) +{ + /* + * If we get here it means the boot console is going away but we + * don't yet have a suitable replacement. Don't pass through to + * the original exit routine. We'll call it later in our deinit() + * function. For now, restore the original exit() function pointer + * as a sentinal that we've hit this point. + */ + con->exit = earlycon_orig_exit; + + return 0; +} + +static void kgdboc_earlycon_deinit(void) +{ + if (!earlycon) + return; + + if (earlycon->exit == kgdboc_earlycon_deferred_exit) + /* + * kgdboc_earlycon is exiting but original boot console exit + * was never called (AKA kgdboc_earlycon_deferred_exit() + * didn't ever run). Undo our trap. + */ + earlycon->exit = earlycon_orig_exit; + else if (earlycon->exit) + /* + * We skipped calling the exit() routine so we could try to + * keep using the boot console even after it went away. We're + * finally done so call the function now. + */ + earlycon->exit(earlycon); + + earlycon = NULL; +} + +static struct kgdb_io kgdboc_earlycon_io_ops = { + .name = "kgdboc_earlycon", + .read_char = kgdboc_earlycon_get_char, + .write_char = kgdboc_earlycon_put_char, + .pre_exception = kgdboc_earlycon_pre_exp_handler, + .deinit = kgdboc_earlycon_deinit, + .is_console = true, +}; + +#define MAX_CONSOLE_NAME_LEN (sizeof((struct console *) 0)->name) +static char kgdboc_earlycon_param[MAX_CONSOLE_NAME_LEN] __initdata; +static bool kgdboc_earlycon_late_enable __initdata; + +static int __init kgdboc_earlycon_init(char *opt) +{ + struct console *con; + + kdb_init(KDB_INIT_EARLY); + + /* + * Look for a matching console, or if the name was left blank just + * pick the first one we find. + */ + console_lock(); + for_each_console(con) { + if (con->write && con->read && + (con->flags & (CON_BOOT | CON_ENABLED)) && + (!opt || !opt[0] || strcmp(con->name, opt) == 0)) + break; + } + + if (!con) { + /* + * Both earlycon and kgdboc_earlycon are initialized during * early parameter parsing. We cannot guarantee earlycon gets + * in first and, in any case, on ACPI systems earlycon may + * defer its own initialization (usually to somewhere within + * setup_arch() ). To cope with either of these situations + * we can defer our own initialization to a little later in + * the boot. + */ + if (!kgdboc_earlycon_late_enable) { + pr_info("No suitable earlycon yet, will try later\n"); + if (opt) + strscpy(kgdboc_earlycon_param, opt, + sizeof(kgdboc_earlycon_param)); + kgdboc_earlycon_late_enable = true; + } else { + pr_info("Couldn't find kgdb earlycon\n"); + } + goto unlock; + } + + earlycon = con; + pr_info("Going to register kgdb with earlycon '%s'\n", con->name); + if (kgdb_register_io_module(&kgdboc_earlycon_io_ops) != 0) { + earlycon = NULL; + pr_info("Failed to register kgdb with earlycon\n"); + } else { + /* Trap exit so we can keep earlycon longer if needed. */ + earlycon_orig_exit = con->exit; + con->exit = kgdboc_earlycon_deferred_exit; + } + +unlock: + console_unlock(); + + /* Non-zero means malformed option so we always return zero */ + return 0; +} + +early_param("kgdboc_earlycon", kgdboc_earlycon_init); + +/* + * This is only intended for the late adoption of an early console. + * + * It is not a reliable way to adopt regular consoles because we can not + * control what order console initcalls are made and, in any case, many + * regular consoles are registered much later in the boot process than + * the console initcalls! + */ +static int __init kgdboc_earlycon_late_init(void) +{ + if (kgdboc_earlycon_late_enable) + kgdboc_earlycon_init(kgdboc_earlycon_param); + return 0; +} +console_initcall(kgdboc_earlycon_late_init); + +#endif /* IS_BUILTIN(CONFIG_KGDB_SERIAL_CONSOLE) */ module_init(init_kgdboc); -module_exit(cleanup_kgdboc); +module_exit(exit_kgdboc); module_param_call(kgdboc, param_set_kgdboc_var, param_get_string, &kps, 0644); MODULE_PARM_DESC(kgdboc, "<serial_device>[,baud]"); MODULE_DESCRIPTION("KGDB Console TTY Driver"); diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 6119090ce045..6bace1c6bb09 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1090,6 +1090,36 @@ static void qcom_geni_serial_earlycon_write(struct console *con, __qcom_geni_serial_console_write(&dev->port, s, n); } +#ifdef CONFIG_CONSOLE_POLL +static int qcom_geni_serial_earlycon_read(struct console *con, + char *s, unsigned int n) +{ + struct earlycon_device *dev = con->data; + struct uart_port *uport = &dev->port; + int num_read = 0; + int ch; + + while (num_read < n) { + ch = qcom_geni_serial_get_char(uport); + if (ch == NO_POLL_CHAR) + break; + s[num_read++] = ch; + } + + return num_read; +} + +static void __init qcom_geni_serial_enable_early_read(struct geni_se *se, + struct console *con) +{ + geni_se_setup_s_cmd(se, UART_START_READ, 0); + con->read = qcom_geni_serial_earlycon_read; +} +#else +static inline void qcom_geni_serial_enable_early_read(struct geni_se *se, + struct console *con) { } +#endif + static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev, const char *opt) { @@ -1136,6 +1166,8 @@ static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev, dev->con->write = qcom_geni_serial_earlycon_write; dev->con->setup = NULL; + qcom_geni_serial_enable_early_read(&se, dev->con); + return 0; } OF_EARLYCON_DECLARE(qcom_geni, "qcom,geni-debug-uart", |