| /* sunhv.c: Serial driver for SUN4V hypervisor console. |
| * |
| * Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net) |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/errno.h> |
| #include <linux/tty.h> |
| #include <linux/tty_flip.h> |
| #include <linux/major.h> |
| #include <linux/circ_buf.h> |
| #include <linux/serial.h> |
| #include <linux/sysrq.h> |
| #include <linux/console.h> |
| #include <linux/spinlock.h> |
| #include <linux/slab.h> |
| #include <linux/delay.h> |
| #include <linux/init.h> |
| #include <linux/of_device.h> |
| |
| #include <asm/hypervisor.h> |
| #include <asm/spitfire.h> |
| #include <asm/prom.h> |
| #include <asm/irq.h> |
| #include <asm/setup.h> |
| |
| #if defined(CONFIG_MAGIC_SYSRQ) |
| #define SUPPORT_SYSRQ |
| #endif |
| |
| #include <linux/serial_core.h> |
| #include <linux/sunserialcore.h> |
| |
| #define CON_BREAK ((long)-1) |
| #define CON_HUP ((long)-2) |
| |
| #define IGNORE_BREAK 0x1 |
| #define IGNORE_ALL 0x2 |
| |
| static char *con_write_page; |
| static char *con_read_page; |
| |
| static int hung_up = 0; |
| |
| static void transmit_chars_putchar(struct uart_port *port, struct circ_buf *xmit) |
| { |
| while (!uart_circ_empty(xmit)) { |
| long status = sun4v_con_putchar(xmit->buf[xmit->tail]); |
| |
| if (status != HV_EOK) |
| break; |
| |
| xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); |
| port->icount.tx++; |
| } |
| } |
| |
| static void transmit_chars_write(struct uart_port *port, struct circ_buf *xmit) |
| { |
| while (!uart_circ_empty(xmit)) { |
| unsigned long ra = __pa(xmit->buf + xmit->tail); |
| unsigned long len, status, sent; |
| |
| len = CIRC_CNT_TO_END(xmit->head, xmit->tail, |
| UART_XMIT_SIZE); |
| status = sun4v_con_write(ra, len, &sent); |
| if (status != HV_EOK) |
| break; |
| xmit->tail = (xmit->tail + sent) & (UART_XMIT_SIZE - 1); |
| port->icount.tx += sent; |
| } |
| } |
| |
| static int receive_chars_getchar(struct uart_port *port) |
| { |
| int saw_console_brk = 0; |
| int limit = 10000; |
| |
| while (limit-- > 0) { |
| long status; |
| long c = sun4v_con_getchar(&status); |
| |
| if (status == HV_EWOULDBLOCK) |
| break; |
| |
| if (c == CON_BREAK) { |
| if (uart_handle_break(port)) |
| continue; |
| saw_console_brk = 1; |
| c = 0; |
| } |
| |
| if (c == CON_HUP) { |
| hung_up = 1; |
| uart_handle_dcd_change(port, 0); |
| } else if (hung_up) { |
| hung_up = 0; |
| uart_handle_dcd_change(port, 1); |
| } |
| |
| if (port->state == NULL) { |
| uart_handle_sysrq_char(port, c); |
| continue; |
| } |
| |
| port->icount.rx++; |
| |
| if (uart_handle_sysrq_char(port, c)) |
| continue; |
| |
| tty_insert_flip_char(&port->state->port, c, TTY_NORMAL); |
| } |
| |
| return saw_console_brk; |
| } |
| |
| static int receive_chars_read(struct uart_port *port) |
| { |
| int saw_console_brk = 0; |
| int limit = 10000; |
| |
| while (limit-- > 0) { |
| unsigned long ra = __pa(con_read_page); |
| unsigned long bytes_read, i; |
| long stat = sun4v_con_read(ra, PAGE_SIZE, &bytes_read); |
| |
| if (stat != HV_EOK) { |
| bytes_read = 0; |
| |
| if (stat == CON_BREAK) { |
| if (uart_handle_break(port)) |
| continue; |
| saw_console_brk = 1; |
| *con_read_page = 0; |
| bytes_read = 1; |
| } else if (stat == CON_HUP) { |
| hung_up = 1; |
| uart_handle_dcd_change(port, 0); |
| continue; |
| } else { |
| /* HV_EWOULDBLOCK, etc. */ |
| break; |
| } |
| } |
| |
| if (hung_up) { |
| hung_up = 0; |
| uart_handle_dcd_change(port, 1); |
| } |
| |
| if (port->sysrq != 0 && *con_read_page) { |
| for (i = 0; i < bytes_read; i++) |
| uart_handle_sysrq_char(port, con_read_page[i]); |
| } |
| |
| if (port->state == NULL) |
| continue; |
| |
| port->icount.rx += bytes_read; |
| |
| tty_insert_flip_string(&port->state->port, con_read_page, |
| bytes_read); |
| } |
| |
| return saw_console_brk; |
| } |
| |
| struct sunhv_ops { |
| void (*transmit_chars)(struct uart_port *port, struct circ_buf *xmit); |
| int (*receive_chars)(struct uart_port *port); |
| }; |
| |
| static const struct sunhv_ops bychar_ops = { |
| .transmit_chars = transmit_chars_putchar, |
| .receive_chars = receive_chars_getchar, |
| }; |
| |
| static const struct sunhv_ops bywrite_ops = { |
| .transmit_chars = transmit_chars_write, |
| .receive_chars = receive_chars_read, |
| }; |
| |
| static const struct sunhv_ops *sunhv_ops = &bychar_ops; |
| |
| static struct tty_port *receive_chars(struct uart_port *port) |
| { |
| struct tty_port *tport = NULL; |
| |
| if (port->state != NULL) /* Unopened serial console */ |
| tport = &port->state->port; |
| |
| if (sunhv_ops->receive_chars(port)) |
| sun_do_break(); |
| |
| return tport; |
| } |
| |
| static void transmit_chars(struct uart_port *port) |
| { |
| struct circ_buf *xmit; |
| |
| if (!port->state) |
| return; |
| |
| xmit = &port->state->xmit; |
| if (uart_circ_empty(xmit) || uart_tx_stopped(port)) |
| return; |
| |
| sunhv_ops->transmit_chars(port, xmit); |
| |
| if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) |
| uart_write_wakeup(port); |
| } |
| |
| static irqreturn_t sunhv_interrupt(int irq, void *dev_id) |
| { |
| struct uart_port *port = dev_id; |
| struct tty_port *tport; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&port->lock, flags); |
| tport = receive_chars(port); |
| transmit_chars(port); |
| spin_unlock_irqrestore(&port->lock, flags); |
| |
| if (tport) |
| tty_flip_buffer_push(tport); |
| |
| return IRQ_HANDLED; |
| } |
| |
| /* port->lock is not held. */ |
| static unsigned int sunhv_tx_empty(struct uart_port *port) |
| { |
| /* Transmitter is always empty for us. If the circ buffer |
| * is non-empty or there is an x_char pending, our caller |
| * will do the right thing and ignore what we return here. |
| */ |
| return TIOCSER_TEMT; |
| } |
| |
| /* port->lock held by caller. */ |
| static void sunhv_set_mctrl(struct uart_port *port, unsigned int mctrl) |
| { |
| return; |
| } |
| |
| /* port->lock is held by caller and interrupts are disabled. */ |
| static unsigned int sunhv_get_mctrl(struct uart_port *port) |
| { |
| return TIOCM_DSR | TIOCM_CAR | TIOCM_CTS; |
| } |
| |
| /* port->lock held by caller. */ |
| static void sunhv_stop_tx(struct uart_port *port) |
| { |
| return; |
| } |
| |
| /* port->lock held by caller. */ |
| static void sunhv_start_tx(struct uart_port *port) |
| { |
| transmit_chars(port); |
| } |
| |
| /* port->lock is not held. */ |
| static void sunhv_send_xchar(struct uart_port *port, char ch) |
| { |
| unsigned long flags; |
| int limit = 10000; |
| |
| if (ch == __DISABLED_CHAR) |
| return; |
| |
| spin_lock_irqsave(&port->lock, flags); |
| |
| while (limit-- > 0) { |
| long status = sun4v_con_putchar(ch); |
| if (status == HV_EOK) |
| break; |
| udelay(1); |
| } |
| |
| spin_unlock_irqrestore(&port->lock, flags); |
| } |
| |
| /* port->lock held by caller. */ |
| static void sunhv_stop_rx(struct uart_port *port) |
| { |
| } |
| |
| /* port->lock is not held. */ |
| static void sunhv_break_ctl(struct uart_port *port, int break_state) |
| { |
| if (break_state) { |
| unsigned long flags; |
| int limit = 10000; |
| |
| spin_lock_irqsave(&port->lock, flags); |
| |
| while (limit-- > 0) { |
| long status = sun4v_con_putchar(CON_BREAK); |
| if (status == HV_EOK) |
| break; |
| udelay(1); |
| } |
| |
| spin_unlock_irqrestore(&port->lock, flags); |
| } |
| } |
| |
| /* port->lock is not held. */ |
| static int sunhv_startup(struct uart_port *port) |
| { |
| return 0; |
| } |
| |
| /* port->lock is not held. */ |
| static void sunhv_shutdown(struct uart_port *port) |
| { |
| } |
| |
| /* port->lock is not held. */ |
| static void sunhv_set_termios(struct uart_port *port, struct ktermios *termios, |
| struct ktermios *old) |
| { |
| unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000); |
| unsigned int quot = uart_get_divisor(port, baud); |
| unsigned int iflag, cflag; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&port->lock, flags); |
| |
| iflag = termios->c_iflag; |
| cflag = termios->c_cflag; |
| |
| port->ignore_status_mask = 0; |
| if (iflag & IGNBRK) |
| port->ignore_status_mask |= IGNORE_BREAK; |
| if ((cflag & CREAD) == 0) |
| port->ignore_status_mask |= IGNORE_ALL; |
| |
| /* XXX */ |
| uart_update_timeout(port, cflag, |
| (port->uartclk / (16 * quot))); |
| |
| spin_unlock_irqrestore(&port->lock, flags); |
| } |
| |
| static const char *sunhv_type(struct uart_port *port) |
| { |
| return "SUN4V HCONS"; |
| } |
| |
| static void sunhv_release_port(struct uart_port *port) |
| { |
| } |
| |
| static int sunhv_request_port(struct uart_port *port) |
| { |
| return 0; |
| } |
| |
| static void sunhv_config_port(struct uart_port *port, int flags) |
| { |
| } |
| |
| static int sunhv_verify_port(struct uart_port *port, struct serial_struct *ser) |
| { |
| return -EINVAL; |
| } |
| |
| static const struct uart_ops sunhv_pops = { |
| .tx_empty = sunhv_tx_empty, |
| .set_mctrl = sunhv_set_mctrl, |
| .get_mctrl = sunhv_get_mctrl, |
| .stop_tx = sunhv_stop_tx, |
| .start_tx = sunhv_start_tx, |
| .send_xchar = sunhv_send_xchar, |
| .stop_rx = sunhv_stop_rx, |
| .break_ctl = sunhv_break_ctl, |
| .startup = sunhv_startup, |
| .shutdown = sunhv_shutdown, |
| .set_termios = sunhv_set_termios, |
| .type = sunhv_type, |
| .release_port = sunhv_release_port, |
| .request_port = sunhv_request_port, |
| .config_port = sunhv_config_port, |
| .verify_port = sunhv_verify_port, |
| }; |
| |
| static struct uart_driver sunhv_reg = { |
| .owner = THIS_MODULE, |
| .driver_name = "sunhv", |
| .dev_name = "ttyS", |
| .major = TTY_MAJOR, |
| }; |
| |
| static struct uart_port *sunhv_port; |
| |
| void sunhv_migrate_hvcons_irq(int cpu) |
| { |
| /* Migrate hvcons irq to param cpu */ |
| irq_force_affinity(sunhv_port->irq, cpumask_of(cpu)); |
| } |
| |
| /* Copy 's' into the con_write_page, decoding "\n" into |
| * "\r\n" along the way. We have to return two lengths |
| * because the caller needs to know how much to advance |
| * 's' and also how many bytes to output via con_write_page. |
| */ |
| static int fill_con_write_page(const char *s, unsigned int n, |
| unsigned long *page_bytes) |
| { |
| const char *orig_s = s; |
| char *p = con_write_page; |
| int left = PAGE_SIZE; |
| |
| while (n--) { |
| if (*s == '\n') { |
| if (left < 2) |
| break; |
| *p++ = '\r'; |
| left--; |
| } else if (left < 1) |
| break; |
| *p++ = *s++; |
| left--; |
| } |
| *page_bytes = p - con_write_page; |
| return s - orig_s; |
| } |
| |
| static void sunhv_console_write_paged(struct console *con, const char *s, unsigned n) |
| { |
| struct uart_port *port = sunhv_port; |
| unsigned long flags; |
| int locked = 1; |
| |
| if (port->sysrq || oops_in_progress) |
| locked = spin_trylock_irqsave(&port->lock, flags); |
| else |
| spin_lock_irqsave(&port->lock, flags); |
| |
| while (n > 0) { |
| unsigned long ra = __pa(con_write_page); |
| unsigned long page_bytes; |
| unsigned int cpy = fill_con_write_page(s, n, |
| &page_bytes); |
| |
| n -= cpy; |
| s += cpy; |
| while (page_bytes > 0) { |
| unsigned long written; |
| int limit = 1000000; |
| |
| while (limit--) { |
| unsigned long stat; |
| |
| stat = sun4v_con_write(ra, page_bytes, |
| &written); |
| if (stat == HV_EOK) |
| break; |
| udelay(1); |
| } |
| if (limit < 0) |
| break; |
| page_bytes -= written; |
| ra += written; |
| } |
| } |
| |
| if (locked) |
| spin_unlock_irqrestore(&port->lock, flags); |
| } |
| |
| static inline void sunhv_console_putchar(struct uart_port *port, char c) |
| { |
| int limit = 1000000; |
| |
| while (limit-- > 0) { |
| long status = sun4v_con_putchar(c); |
| if (status == HV_EOK) |
| break; |
| udelay(1); |
| } |
| } |
| |
| static void sunhv_console_write_bychar(struct console *con, const char *s, unsigned n) |
| { |
| struct uart_port *port = sunhv_port; |
| unsigned long flags; |
| int i, locked = 1; |
| |
| if (port->sysrq || oops_in_progress) |
| locked = spin_trylock_irqsave(&port->lock, flags); |
| else |
| spin_lock_irqsave(&port->lock, flags); |
| |
| for (i = 0; i < n; i++) { |
| if (*s == '\n') |
| sunhv_console_putchar(port, '\r'); |
| sunhv_console_putchar(port, *s++); |
| } |
| |
| if (locked) |
| spin_unlock_irqrestore(&port->lock, flags); |
| } |
| |
| static struct console sunhv_console = { |
| .name = "ttyHV", |
| .write = sunhv_console_write_bychar, |
| .device = uart_console_device, |
| .flags = CON_PRINTBUFFER, |
| .index = -1, |
| .data = &sunhv_reg, |
| }; |
| |
| static int hv_probe(struct platform_device *op) |
| { |
| struct uart_port *port; |
| unsigned long minor; |
| int err; |
| |
| if (op->archdata.irqs[0] == 0xffffffff) |
| return -ENODEV; |
| |
| port = kzalloc(sizeof(struct uart_port), GFP_KERNEL); |
| if (unlikely(!port)) |
| return -ENOMEM; |
| |
| minor = 1; |
| if (sun4v_hvapi_register(HV_GRP_CORE, 1, &minor) == 0 && |
| minor >= 1) { |
| err = -ENOMEM; |
| con_write_page = kzalloc(PAGE_SIZE, GFP_KERNEL); |
| if (!con_write_page) |
| goto out_free_port; |
| |
| con_read_page = kzalloc(PAGE_SIZE, GFP_KERNEL); |
| if (!con_read_page) |
| goto out_free_con_write_page; |
| |
| sunhv_console.write = sunhv_console_write_paged; |
| sunhv_ops = &bywrite_ops; |
| } |
| |
| sunhv_port = port; |
| |
| port->line = 0; |
| port->ops = &sunhv_pops; |
| port->type = PORT_SUNHV; |
| port->uartclk = ( 29491200 / 16 ); /* arbitrary */ |
| |
| port->membase = (unsigned char __iomem *) __pa(port); |
| |
| port->irq = op->archdata.irqs[0]; |
| |
| port->dev = &op->dev; |
| |
| err = sunserial_register_minors(&sunhv_reg, 1); |
| if (err) |
| goto out_free_con_read_page; |
| |
| sunserial_console_match(&sunhv_console, op->dev.of_node, |
| &sunhv_reg, port->line, false); |
| |
| err = uart_add_one_port(&sunhv_reg, port); |
| if (err) |
| goto out_unregister_driver; |
| |
| err = request_irq(port->irq, sunhv_interrupt, 0, "hvcons", port); |
| if (err) |
| goto out_remove_port; |
| |
| platform_set_drvdata(op, port); |
| |
| return 0; |
| |
| out_remove_port: |
| uart_remove_one_port(&sunhv_reg, port); |
| |
| out_unregister_driver: |
| sunserial_unregister_minors(&sunhv_reg, 1); |
| |
| out_free_con_read_page: |
| kfree(con_read_page); |
| |
| out_free_con_write_page: |
| kfree(con_write_page); |
| |
| out_free_port: |
| kfree(port); |
| sunhv_port = NULL; |
| return err; |
| } |
| |
| static int hv_remove(struct platform_device *dev) |
| { |
| struct uart_port *port = platform_get_drvdata(dev); |
| |
| free_irq(port->irq, port); |
| |
| uart_remove_one_port(&sunhv_reg, port); |
| |
| sunserial_unregister_minors(&sunhv_reg, 1); |
| kfree(con_read_page); |
| kfree(con_write_page); |
| kfree(port); |
| sunhv_port = NULL; |
| |
| return 0; |
| } |
| |
| static const struct of_device_id hv_match[] = { |
| { |
| .name = "console", |
| .compatible = "qcn", |
| }, |
| { |
| .name = "console", |
| .compatible = "SUNW,sun4v-console", |
| }, |
| {}, |
| }; |
| |
| static struct platform_driver hv_driver = { |
| .driver = { |
| .name = "hv", |
| .of_match_table = hv_match, |
| }, |
| .probe = hv_probe, |
| .remove = hv_remove, |
| }; |
| |
| static int __init sunhv_init(void) |
| { |
| if (tlb_type != hypervisor) |
| return -ENODEV; |
| |
| return platform_driver_register(&hv_driver); |
| } |
| device_initcall(sunhv_init); |
| |
| #if 0 /* ...def MODULE ; never supported as such */ |
| MODULE_AUTHOR("David S. Miller"); |
| MODULE_DESCRIPTION("SUN4V Hypervisor console driver"); |
| MODULE_VERSION("2.0"); |
| MODULE_LICENSE("GPL"); |
| #endif |