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parisc: Convert PDC console to an early console
Rewrite the PDC console to become an early console. Beside the fact that now boot information is visible until another (text- or graphics) console takes over, this benefits as well machines with a yet-unsupported STI console and kgdb. Signed-off-by: Helge Deller <[email protected]>
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,46 +1,18 @@ | ||
| // SPDX-License-Identifier: GPL-2.0-or-later | ||
| /* | ||
| * PDC Console support - ie use firmware to dump text via boot console | ||
| * PDC early console support - use PDC firmware to dump text via boot console | ||
| * | ||
| * Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org> | ||
| * Copyright (C) 2000 Martin K Petersen <mkp at mkp.net> | ||
| * Copyright (C) 2000 John Marvin <jsm at parisc-linux.org> | ||
| * Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org> | ||
| * Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org> | ||
| * Copyright (C) 2000 Michael Ang <mang with subcarrier.org> | ||
| * Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org> | ||
| * Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org> | ||
| * Copyright (C) 2001 Helge Deller <deller at parisc-linux.org> | ||
| * Copyright (C) 2001 Thomas Bogendoerfer <tsbogend at parisc-linux.org> | ||
| * Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org> | ||
| * Copyright (C) 2010 Guy Martin <gmsoft at tuxicoman.be> | ||
| * Copyright (C) 2001-2022 Helge Deller <[email protected]> | ||
| */ | ||
|
|
||
| /* | ||
| * The PDC console is a simple console, which can be used for debugging | ||
| * boot related problems on HP PA-RISC machines. It is also useful when no | ||
| * other console works. | ||
| * | ||
| * This code uses the ROM (=PDC) based functions to read and write characters | ||
| * from and to PDC's boot path. | ||
| */ | ||
|
|
||
| /* Define EARLY_BOOTUP_DEBUG to debug kernel related boot problems. | ||
| * On production kernels EARLY_BOOTUP_DEBUG should be undefined. */ | ||
| #define EARLY_BOOTUP_DEBUG | ||
|
|
||
|
|
||
| #include <linux/kernel.h> | ||
| #include <linux/console.h> | ||
| #include <linux/string.h> | ||
| #include <linux/init.h> | ||
| #include <linux/major.h> | ||
| #include <linux/tty.h> | ||
| #include <linux/serial_core.h> | ||
| #include <linux/kgdb.h> | ||
| #include <asm/page.h> /* for PAGE0 */ | ||
| #include <asm/pdc.h> /* for iodc_call() proto and friends */ | ||
|
|
||
| static DEFINE_SPINLOCK(pdc_console_lock); | ||
| static struct console pdc_cons; | ||
|
|
||
| static void pdc_console_write(struct console *co, const char *s, unsigned count) | ||
| { | ||
|
|
@@ -54,7 +26,8 @@ static void pdc_console_write(struct console *co, const char *s, unsigned count) | |
| spin_unlock_irqrestore(&pdc_console_lock, flags); | ||
| } | ||
|
|
||
| int pdc_console_poll_key(struct console *co) | ||
| #ifdef CONFIG_KGDB | ||
| static int kgdb_pdc_read_char(void) | ||
| { | ||
| int c; | ||
| unsigned long flags; | ||
|
|
@@ -63,201 +36,40 @@ int pdc_console_poll_key(struct console *co) | |
| c = pdc_iodc_getc(); | ||
| spin_unlock_irqrestore(&pdc_console_lock, flags); | ||
|
|
||
| return c; | ||
| } | ||
|
|
||
| static int pdc_console_setup(struct console *co, char *options) | ||
| { | ||
| return 0; | ||
| } | ||
|
|
||
| #if defined(CONFIG_PDC_CONSOLE) | ||
| #include <linux/vt_kern.h> | ||
| #include <linux/tty_flip.h> | ||
|
|
||
| #define PDC_CONS_POLL_DELAY (30 * HZ / 1000) | ||
|
|
||
| static void pdc_console_poll(struct timer_list *unused); | ||
| static DEFINE_TIMER(pdc_console_timer, pdc_console_poll); | ||
| static struct tty_port tty_port; | ||
|
|
||
| static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp) | ||
| { | ||
| tty_port_tty_set(&tty_port, tty); | ||
| mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY); | ||
|
|
||
| return 0; | ||
| return (c <= 0) ? NO_POLL_CHAR : c; | ||
| } | ||
|
|
||
| static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp) | ||
| static void kgdb_pdc_write_char(u8 chr) | ||
| { | ||
| if (tty->count == 1) { | ||
| del_timer_sync(&pdc_console_timer); | ||
| tty_port_tty_set(&tty_port, NULL); | ||
| } | ||
| if (PAGE0->mem_cons.cl_class != CL_DUPLEX) | ||
| pdc_console_write(NULL, &chr, 1); | ||
| } | ||
|
|
||
| static int pdc_console_tty_write(struct tty_struct *tty, const unsigned char *buf, int count) | ||
| { | ||
| pdc_console_write(NULL, buf, count); | ||
| return count; | ||
| } | ||
|
|
||
| static unsigned int pdc_console_tty_write_room(struct tty_struct *tty) | ||
| { | ||
| return 32768; /* no limit, no buffer used */ | ||
| } | ||
|
|
||
| static const struct tty_operations pdc_console_tty_ops = { | ||
| .open = pdc_console_tty_open, | ||
| .close = pdc_console_tty_close, | ||
| .write = pdc_console_tty_write, | ||
| .write_room = pdc_console_tty_write_room, | ||
| static struct kgdb_io kgdb_pdc_io_ops = { | ||
| .name = "kgdb_pdc", | ||
| .read_char = kgdb_pdc_read_char, | ||
| .write_char = kgdb_pdc_write_char, | ||
| }; | ||
|
|
||
| static void pdc_console_poll(struct timer_list *unused) | ||
| { | ||
| int data, count = 0; | ||
|
|
||
| while (1) { | ||
| data = pdc_console_poll_key(NULL); | ||
| if (data == -1) | ||
| break; | ||
| tty_insert_flip_char(&tty_port, data & 0xFF, TTY_NORMAL); | ||
| count ++; | ||
| } | ||
|
|
||
| if (count) | ||
| tty_flip_buffer_push(&tty_port); | ||
|
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||
| if (pdc_cons.flags & CON_ENABLED) | ||
| mod_timer(&pdc_console_timer, jiffies + PDC_CONS_POLL_DELAY); | ||
| } | ||
|
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||
| static struct tty_driver *pdc_console_tty_driver; | ||
|
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||
| static int __init pdc_console_tty_driver_init(void) | ||
| { | ||
| struct tty_driver *driver; | ||
| int err; | ||
|
|
||
| /* Check if the console driver is still registered. | ||
| * It is unregistered if the pdc console was not selected as the | ||
| * primary console. */ | ||
|
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||
| struct console *tmp; | ||
|
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| console_lock(); | ||
| for_each_console(tmp) | ||
| if (tmp == &pdc_cons) | ||
| break; | ||
| console_unlock(); | ||
|
|
||
| if (!tmp) { | ||
| printk(KERN_INFO "PDC console driver not registered anymore, not creating %s\n", pdc_cons.name); | ||
| return -ENODEV; | ||
| } | ||
|
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||
| printk(KERN_INFO "The PDC console driver is still registered, removing CON_BOOT flag\n"); | ||
| pdc_cons.flags &= ~CON_BOOT; | ||
|
|
||
| driver = tty_alloc_driver(1, TTY_DRIVER_REAL_RAW | | ||
| TTY_DRIVER_RESET_TERMIOS); | ||
| if (IS_ERR(driver)) | ||
| return PTR_ERR(driver); | ||
|
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||
| tty_port_init(&tty_port); | ||
|
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||
| driver->driver_name = "pdc_cons"; | ||
| driver->name = "ttyB"; | ||
| driver->major = MUX_MAJOR; | ||
| driver->minor_start = 0; | ||
| driver->type = TTY_DRIVER_TYPE_SYSTEM; | ||
| driver->init_termios = tty_std_termios; | ||
| tty_set_operations(driver, &pdc_console_tty_ops); | ||
| tty_port_link_device(&tty_port, driver, 0); | ||
|
|
||
| err = tty_register_driver(driver); | ||
| if (err) { | ||
| printk(KERN_ERR "Unable to register the PDC console TTY driver\n"); | ||
| tty_port_destroy(&tty_port); | ||
| tty_driver_kref_put(driver); | ||
| return err; | ||
| } | ||
|
|
||
| pdc_console_tty_driver = driver; | ||
|
|
||
| return 0; | ||
| } | ||
| device_initcall(pdc_console_tty_driver_init); | ||
|
|
||
| static struct tty_driver * pdc_console_device (struct console *c, int *index) | ||
| { | ||
| *index = c->index; | ||
| return pdc_console_tty_driver; | ||
| } | ||
| #else | ||
| #define pdc_console_device NULL | ||
| #endif | ||
|
|
||
| static struct console pdc_cons = { | ||
| .name = "ttyB", | ||
| .write = pdc_console_write, | ||
| .device = pdc_console_device, | ||
| .setup = pdc_console_setup, | ||
| .flags = CON_BOOT | CON_PRINTBUFFER, | ||
| .index = -1, | ||
| }; | ||
|
|
||
| static int pdc_console_initialized; | ||
|
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||
| static void pdc_console_init_force(void) | ||
| static int __init pdc_earlycon_setup(struct earlycon_device *device, | ||
| const char *opt) | ||
| { | ||
| if (pdc_console_initialized) | ||
| return; | ||
| ++pdc_console_initialized; | ||
|
|
||
| struct console *earlycon_console; | ||
|
|
||
| /* If the console is duplex then copy the COUT parameters to CIN. */ | ||
| if (PAGE0->mem_cons.cl_class == CL_DUPLEX) | ||
| memcpy(&PAGE0->mem_kbd, &PAGE0->mem_cons, sizeof(PAGE0->mem_cons)); | ||
|
|
||
| /* register the pdc console */ | ||
| register_console(&pdc_cons); | ||
| } | ||
| earlycon_console = device->con; | ||
| earlycon_console->write = pdc_console_write; | ||
| device->port.iotype = UPIO_MEM32BE; | ||
|
|
||
| void __init pdc_console_init(void) | ||
| { | ||
| #if defined(EARLY_BOOTUP_DEBUG) || defined(CONFIG_PDC_CONSOLE) | ||
| pdc_console_init_force(); | ||
| #ifdef CONFIG_KGDB | ||
| kgdb_register_io_module(&kgdb_pdc_io_ops); | ||
| #endif | ||
| #ifdef EARLY_BOOTUP_DEBUG | ||
| printk(KERN_INFO "Initialized PDC Console for debugging.\n"); | ||
| #endif | ||
| } | ||
|
|
||
|
|
||
| /* | ||
| * Used for emergencies. Currently only used if an HPMC occurs. If an | ||
| * HPMC occurs, it is possible that the current console may not be | ||
| * properly initialised after the PDC IO reset. This routine unregisters | ||
| * all of the current consoles, reinitializes the pdc console and | ||
| * registers it. | ||
| */ | ||
|
|
||
| void pdc_console_restart(void) | ||
| { | ||
| struct console *console; | ||
|
|
||
| if (pdc_console_initialized) | ||
| return; | ||
|
|
||
| /* If we've already seen the output, don't bother to print it again */ | ||
| if (console_drivers != NULL) | ||
| pdc_cons.flags &= ~CON_PRINTBUFFER; | ||
|
|
||
| while ((console = console_drivers) != NULL) | ||
| unregister_console(console_drivers); | ||
|
|
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| /* force registering the pdc console */ | ||
| pdc_console_init_force(); | ||
| return 0; | ||
| } | ||
|
|
||
| EARLYCON_DECLARE(pdc, pdc_earlycon_setup); | ||
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