[linux-2.6-block.git] / drivers / tty / serial / sunhv.c

// SPDX-License-Identifier: GPL-2.0
/* 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)
{
	static int saw_console_brk;
	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 (saw_console_brk)
					sun_do_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]);
			saw_console_brk = 0;
		}

		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
Commit	Line	Data
e3b3d0f5	1	// SPDX-License-Identifier: GPL-2.0
02fd473b DM	2	/* sunhv.c: Serial driver for SUN4V hypervisor console.
02fd473b DM	3	*
c7754d46	4	* Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net)
02fd473b DM	5	*/
02fd473b DM	6
02fd473b DM	7	#include <linux/kernel.h>
	8	#include <linux/errno.h>
	9	#include <linux/tty.h>
	10	#include <linux/tty_flip.h>
	11	#include <linux/major.h>
	12	#include <linux/circ_buf.h>
	13	#include <linux/serial.h>
	14	#include <linux/sysrq.h>
	15	#include <linux/console.h>
	16	#include <linux/spinlock.h>
	17	#include <linux/slab.h>
	18	#include <linux/delay.h>
	19	#include <linux/init.h>
c6ed413d	20	#include <linux/of_device.h>
02fd473b DM	21
	22	#include <asm/hypervisor.h>
	23	#include <asm/spitfire.h>
93872ba2	24	#include <asm/prom.h>
f4266ab4	25	#include <asm/irq.h>
d550bbd4	26	#include <asm/setup.h>
02fd473b DM	27
	28	#if defined(CONFIG_MAGIC_SYSRQ)
	29	#define SUPPORT_SYSRQ
	30	#endif
	31
	32	#include <linux/serial_core.h>
6816383a	33	#include <linux/sunserialcore.h>
02fd473b DM	34
	35	#define CON_BREAK ((long)-1)
	36	#define CON_HUP ((long)-2)
	37
c7754d46 DM	38	#define IGNORE_BREAK 0x1
c7754d46 DM	39	#define IGNORE_ALL 0x2
02fd473b	40
c7754d46 DM	41	static char *con_write_page;
c7754d46 DM	42	static char *con_read_page;
02fd473b	43
c7754d46	44	static int hung_up = 0;
02fd473b	45
c7754d46	46	static void transmit_chars_putchar(struct uart_port port, struct circ_buf xmit)
02fd473b	47	{
c7754d46 DM	48	while (!uart_circ_empty(xmit)) {
c7754d46 DM	49	long status = sun4v_con_putchar(xmit->buf[xmit->tail]);
02fd473b	50
c7754d46 DM	51	if (status != HV_EOK)
c7754d46 DM	52	break;
02fd473b	53
c7754d46 DM	54	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
	55	port->icount.tx++;
	56	}
02fd473b DM	57	}
02fd473b DM	58
c7754d46 DM	59	static void transmit_chars_write(struct uart_port port, struct circ_buf xmit)
	60	{
	61	while (!uart_circ_empty(xmit)) {
	62	unsigned long ra = __pa(xmit->buf + xmit->tail);
	63	unsigned long len, status, sent;
02fd473b	64
c7754d46 DM	65	len = CIRC_CNT_TO_END(xmit->head, xmit->tail,
	66	UART_XMIT_SIZE);
	67	status = sun4v_con_write(ra, len, &sent);
	68	if (status != HV_EOK)
	69	break;
	70	xmit->tail = (xmit->tail + sent) & (UART_XMIT_SIZE - 1);
	71	port->icount.tx += sent;
	72	}
	73	}
02fd473b	74
05c7cd39	75	static int receive_chars_getchar(struct uart_port *port)
02fd473b	76	{
02fd473b DM	77	int saw_console_brk = 0;
	78	int limit = 10000;
	79
02fd473b DM	80	while (limit-- > 0) {
02fd473b DM	81	long status;
c7754d46	82	long c = sun4v_con_getchar(&status);
02fd473b DM	83
	84	if (status == HV_EWOULDBLOCK)
	85	break;
	86
	87	if (c == CON_BREAK) {
135066a2 DM	88	if (uart_handle_break(port))
135066a2 DM	89	continue;
02fd473b DM	90	saw_console_brk = 1;
	91	c = 0;
	92	}
	93
	94	if (c == CON_HUP) {
	95	hung_up = 1;
	96	uart_handle_dcd_change(port, 0);
	97	} else if (hung_up) {
	98	hung_up = 0;
	99	uart_handle_dcd_change(port, 1);
	100	}
	101
92a19f9c	102	if (port->state == NULL) {
7d12e780	103	uart_handle_sysrq_char(port, c);
02fd473b DM	104	continue;
	105	}
	106
02fd473b	107	port->icount.rx++;
02fd473b	108
7d12e780	109	if (uart_handle_sysrq_char(port, c))
02fd473b DM	110	continue;
02fd473b DM	111
92a19f9c	112	tty_insert_flip_char(&port->state->port, c, TTY_NORMAL);
c7754d46 DM	113	}
	114
	115	return saw_console_brk;
	116	}
	117
05c7cd39	118	static int receive_chars_read(struct uart_port *port)
c7754d46	119	{
7db60d05	120	static int saw_console_brk;
c7754d46 DM	121	int limit = 10000;
	122
	123	while (limit-- > 0) {
	124	unsigned long ra = __pa(con_read_page);
	125	unsigned long bytes_read, i;
	126	long stat = sun4v_con_read(ra, PAGE_SIZE, &bytes_read);
	127
	128	if (stat != HV_EOK) {
	129	bytes_read = 0;
	130
	131	if (stat == CON_BREAK) {
7db60d05 VK	132	if (saw_console_brk)
	133	sun_do_break();
	134
c7754d46 DM	135	if (uart_handle_break(port))
	136	continue;
	137	saw_console_brk = 1;
	138	*con_read_page = 0;
	139	bytes_read = 1;
	140	} else if (stat == CON_HUP) {
	141	hung_up = 1;
	142	uart_handle_dcd_change(port, 0);
	143	continue;
	144	} else {
	145	/* HV_EWOULDBLOCK, etc. */
	146	break;
	147	}
	148	}
	149
	150	if (hung_up) {
	151	hung_up = 0;
	152	uart_handle_dcd_change(port, 1);
	153	}
	154
079317a6 VK	155	if (port->sysrq != 0 && *con_read_page) {
	156	for (i = 0; i < bytes_read; i++)
	157	uart_handle_sysrq_char(port, con_read_page[i]);
7db60d05	158	saw_console_brk = 0;
079317a6	159	}
c7754d46	160
05c7cd39	161	if (port->state == NULL)
02fd473b DM	162	continue;
02fd473b DM	163
c7754d46 DM	164	port->icount.rx += bytes_read;
c7754d46 DM	165
05c7cd39 JS	166	tty_insert_flip_string(&port->state->port, con_read_page,
05c7cd39 JS	167	bytes_read);
02fd473b DM	168	}
02fd473b DM	169
c7754d46 DM	170	return saw_console_brk;
	171	}
	172
	173	struct sunhv_ops {
	174	void (transmit_chars)(struct uart_port port, struct circ_buf *xmit);
05c7cd39	175	int (receive_chars)(struct uart_port port);
c7754d46 DM	176	};
c7754d46 DM	177
01fd3c27	178	static const struct sunhv_ops bychar_ops = {
c7754d46 DM	179	.transmit_chars = transmit_chars_putchar,
	180	.receive_chars = receive_chars_getchar,
	181	};
	182
01fd3c27	183	static const struct sunhv_ops bywrite_ops = {
c7754d46 DM	184	.transmit_chars = transmit_chars_write,
	185	.receive_chars = receive_chars_read,
	186	};
	187
01fd3c27	188	static const struct sunhv_ops *sunhv_ops = &bychar_ops;
c7754d46	189
2e124b4a	190	static struct tty_port receive_chars(struct uart_port port)
c7754d46	191	{
2e124b4a	192	struct tty_port *tport = NULL;
c7754d46	193
ebd2c8f6	194	if (port->state != NULL) /* Unopened serial console */
2e124b4a	195	tport = &port->state->port;
c7754d46	196
05c7cd39	197	if (sunhv_ops->receive_chars(port))
02fd473b DM	198	sun_do_break();
02fd473b DM	199
2e124b4a	200	return tport;
02fd473b DM	201	}
	202
	203	static void transmit_chars(struct uart_port *port)
	204	{
db33f9bc DM	205	struct circ_buf *xmit;
db33f9bc DM	206
ebd2c8f6	207	if (!port->state)
db33f9bc	208	return;
02fd473b	209
ebd2c8f6	210	xmit = &port->state->xmit;
02fd473b DM	211	if (uart_circ_empty(xmit) \|\| uart_tx_stopped(port))
	212	return;
	213
c7754d46	214	sunhv_ops->transmit_chars(port, xmit);
02fd473b DM	215
	216	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
	217	uart_write_wakeup(port);
	218	}
	219
7d12e780	220	static irqreturn_t sunhv_interrupt(int irq, void *dev_id)
02fd473b DM	221	{
02fd473b DM	222	struct uart_port *port = dev_id;
2e124b4a	223	struct tty_port *tport;
02fd473b DM	224	unsigned long flags;
	225
	226	spin_lock_irqsave(&port->lock, flags);
2e124b4a	227	tport = receive_chars(port);
02fd473b DM	228	transmit_chars(port);
	229	spin_unlock_irqrestore(&port->lock, flags);
	230
2e124b4a JS	231	if (tport)
2e124b4a JS	232	tty_flip_buffer_push(tport);
02fd473b DM	233
	234	return IRQ_HANDLED;
	235	}
	236
	237	/* port->lock is not held. */
	238	static unsigned int sunhv_tx_empty(struct uart_port *port)
	239	{
	240	/* Transmitter is always empty for us. If the circ buffer
	241	* is non-empty or there is an x_char pending, our caller
	242	* will do the right thing and ignore what we return here.
	243	*/
	244	return TIOCSER_TEMT;
	245	}
	246
	247	/* port->lock held by caller. */
	248	static void sunhv_set_mctrl(struct uart_port *port, unsigned int mctrl)
	249	{
	250	return;
	251	}
	252
	253	/* port->lock is held by caller and interrupts are disabled. */
	254	static unsigned int sunhv_get_mctrl(struct uart_port *port)
	255	{
	256	return TIOCM_DSR \| TIOCM_CAR \| TIOCM_CTS;
	257	}
	258
	259	/* port->lock held by caller. */
	260	static void sunhv_stop_tx(struct uart_port *port)
	261	{
	262	return;
	263	}
	264
	265	/* port->lock held by caller. */
	266	static void sunhv_start_tx(struct uart_port *port)
	267	{
f798634d	268	transmit_chars(port);
02fd473b DM	269	}
	270
	271	/* port->lock is not held. */
	272	static void sunhv_send_xchar(struct uart_port *port, char ch)
	273	{
	274	unsigned long flags;
	275	int limit = 10000;
	276
db106df3 PH	277	if (ch == __DISABLED_CHAR)
	278	return;
	279
02fd473b DM	280	spin_lock_irqsave(&port->lock, flags);
	281
	282	while (limit-- > 0) {
c7754d46	283	long status = sun4v_con_putchar(ch);
02fd473b DM	284	if (status == HV_EOK)
02fd473b DM	285	break;
c7754d46	286	udelay(1);
02fd473b DM	287	}
	288
	289	spin_unlock_irqrestore(&port->lock, flags);
	290	}
	291
	292	/* port->lock held by caller. */
	293	static void sunhv_stop_rx(struct uart_port *port)
	294	{
	295	}
	296
02fd473b DM	297	/* port->lock is not held. */
	298	static void sunhv_break_ctl(struct uart_port *port, int break_state)
	299	{
	300	if (break_state) {
	301	unsigned long flags;
c7754d46	302	int limit = 10000;
02fd473b DM	303
	304	spin_lock_irqsave(&port->lock, flags);
	305
	306	while (limit-- > 0) {
c7754d46	307	long status = sun4v_con_putchar(CON_BREAK);
02fd473b DM	308	if (status == HV_EOK)
02fd473b DM	309	break;
c7754d46	310	udelay(1);
02fd473b DM	311	}
	312
	313	spin_unlock_irqrestore(&port->lock, flags);
	314	}
	315	}
	316
	317	/* port->lock is not held. */
	318	static int sunhv_startup(struct uart_port *port)
	319	{
	320	return 0;
	321	}
	322
	323	/* port->lock is not held. */
	324	static void sunhv_shutdown(struct uart_port *port)
	325	{
	326	}
	327
	328	/* port->lock is not held. */
606d099c AC	329	static void sunhv_set_termios(struct uart_port port, struct ktermios termios,
606d099c AC	330	struct ktermios *old)
02fd473b DM	331	{
	332	unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
	333	unsigned int quot = uart_get_divisor(port, baud);
	334	unsigned int iflag, cflag;
	335	unsigned long flags;
	336
	337	spin_lock_irqsave(&port->lock, flags);
	338
	339	iflag = termios->c_iflag;
	340	cflag = termios->c_cflag;
	341
	342	port->ignore_status_mask = 0;
	343	if (iflag & IGNBRK)
	344	port->ignore_status_mask \|= IGNORE_BREAK;
	345	if ((cflag & CREAD) == 0)
	346	port->ignore_status_mask \|= IGNORE_ALL;
	347
	348	/* XXX */
	349	uart_update_timeout(port, cflag,
	350	(port->uartclk / (16 * quot)));
	351
	352	spin_unlock_irqrestore(&port->lock, flags);
	353	}
	354
	355	static const char sunhv_type(struct uart_port port)
	356	{
	357	return "SUN4V HCONS";
	358	}
	359
	360	static void sunhv_release_port(struct uart_port *port)
	361	{
	362	}
	363
	364	static int sunhv_request_port(struct uart_port *port)
	365	{
	366	return 0;
	367	}
	368
	369	static void sunhv_config_port(struct uart_port *port, int flags)
	370	{
	371	}
	372
	373	static int sunhv_verify_port(struct uart_port port, struct serial_struct ser)
	374	{
	375	return -EINVAL;
	376	}
	377
2331e068	378	static const struct uart_ops sunhv_pops = {
02fd473b DM	379	.tx_empty = sunhv_tx_empty,
	380	.set_mctrl = sunhv_set_mctrl,
	381	.get_mctrl = sunhv_get_mctrl,
	382	.stop_tx = sunhv_stop_tx,
	383	.start_tx = sunhv_start_tx,
	384	.send_xchar = sunhv_send_xchar,
	385	.stop_rx = sunhv_stop_rx,
02fd473b DM	386	.break_ctl = sunhv_break_ctl,
	387	.startup = sunhv_startup,
	388	.shutdown = sunhv_shutdown,
	389	.set_termios = sunhv_set_termios,
	390	.type = sunhv_type,
	391	.release_port = sunhv_release_port,
	392	.request_port = sunhv_request_port,
	393	.config_port = sunhv_config_port,
	394	.verify_port = sunhv_verify_port,
	395	};
	396
	397	static struct uart_driver sunhv_reg = {
	398	.owner = THIS_MODULE,
32039f49	399	.driver_name = "sunhv",
02fd473b DM	400	.dev_name = "ttyS",
	401	.major = TTY_MAJOR,
	402	};
	403
	404	static struct uart_port *sunhv_port;
	405
7dd4fcf5 VK	406	void sunhv_migrate_hvcons_irq(int cpu)
	407	{
	408	/* Migrate hvcons irq to param cpu */
	409	irq_force_affinity(sunhv_port->irq, cpumask_of(cpu));
	410	}
	411
c7754d46 DM	412	/* Copy 's' into the con_write_page, decoding "\n" into
	413	* "\r\n" along the way. We have to return two lengths
	414	* because the caller needs to know how much to advance
	415	* 's' and also how many bytes to output via con_write_page.
	416	*/
	417	static int fill_con_write_page(const char *s, unsigned int n,
	418	unsigned long *page_bytes)
	419	{
	420	const char *orig_s = s;
	421	char *p = con_write_page;
	422	int left = PAGE_SIZE;
	423
	424	while (n--) {
	425	if (*s == '\n') {
	426	if (left < 2)
	427	break;
	428	*p++ = '\r';
	429	left--;
	430	} else if (left < 1)
	431	break;
	432	p++ = s++;
	433	left--;
	434	}
	435	*page_bytes = p - con_write_page;
	436	return s - orig_s;
	437	}
	438
	439	static void sunhv_console_write_paged(struct console con, const char s, unsigned n)
02fd473b	440	{
c7754d46	441	struct uart_port *port = sunhv_port;
02fd473b	442	unsigned long flags;
f3c681c0 DM	443	int locked = 1;
f3c681c0 DM	444
e58e241c DM	445	if (port->sysrq \|\| oops_in_progress)
	446	locked = spin_trylock_irqsave(&port->lock, flags);
	447	else
	448	spin_lock_irqsave(&port->lock, flags);
02fd473b	449
c7754d46 DM	450	while (n > 0) {
	451	unsigned long ra = __pa(con_write_page);
	452	unsigned long page_bytes;
	453	unsigned int cpy = fill_con_write_page(s, n,
	454	&page_bytes);
	455
	456	n -= cpy;
	457	s += cpy;
	458	while (page_bytes > 0) {
	459	unsigned long written;
	460	int limit = 1000000;
	461
	462	while (limit--) {
	463	unsigned long stat;
	464
	465	stat = sun4v_con_write(ra, page_bytes,
	466	&written);
	467	if (stat == HV_EOK)
	468	break;
	469	udelay(1);
	470	}
52e3632e	471	if (limit < 0)
c7754d46 DM	472	break;
	473	page_bytes -= written;
	474	ra += written;
	475	}
	476	}
f3c681c0 DM	477
f3c681c0 DM	478	if (locked)
e58e241c	479	spin_unlock_irqrestore(&port->lock, flags);
c7754d46 DM	480	}
	481
	482	static inline void sunhv_console_putchar(struct uart_port *port, char c)
	483	{
	484	int limit = 1000000;
02fd473b DM	485
02fd473b DM	486	while (limit-- > 0) {
c7754d46	487	long status = sun4v_con_putchar(c);
02fd473b DM	488	if (status == HV_EOK)
02fd473b DM	489	break;
c7754d46	490	udelay(1);
02fd473b	491	}
02fd473b DM	492	}
02fd473b DM	493
c7754d46	494	static void sunhv_console_write_bychar(struct console con, const char s, unsigned n)
02fd473b DM	495	{
02fd473b DM	496	struct uart_port *port = sunhv_port;
c7754d46	497	unsigned long flags;
f3c681c0 DM	498	int i, locked = 1;
f3c681c0 DM	499
e58e241c DM	500	if (port->sysrq \|\| oops_in_progress)
	501	locked = spin_trylock_irqsave(&port->lock, flags);
	502	else
	503	spin_lock_irqsave(&port->lock, flags);
02fd473b DM	504
	505	for (i = 0; i < n; i++) {
	506	if (*s == '\n')
	507	sunhv_console_putchar(port, '\r');
	508	sunhv_console_putchar(port, *s++);
	509	}
f3c681c0 DM	510
f3c681c0 DM	511	if (locked)
e58e241c	512	spin_unlock_irqrestore(&port->lock, flags);
02fd473b DM	513	}
02fd473b DM	514
02fd473b	515	static struct console sunhv_console = {
d5a2aa24	516	.name = "ttyHV",
c7754d46	517	.write = sunhv_console_write_bychar,
02fd473b	518	.device = uart_console_device,
02fd473b DM	519	.flags = CON_PRINTBUFFER,
	520	.index = -1,
	521	.data = &sunhv_reg,
	522	};
	523
9671f099	524	static int hv_probe(struct platform_device *op)
02fd473b DM	525	{
02fd473b DM	526	struct uart_port *port;
c7754d46	527	unsigned long minor;
93872ba2	528	int err;
02fd473b	529
1636f8ac	530	if (op->archdata.irqs[0] == 0xffffffff)
02fd473b DM	531	return -ENODEV;
02fd473b DM	532
93872ba2	533	port = kzalloc(sizeof(struct uart_port), GFP_KERNEL);
02fd473b DM	534	if (unlikely(!port))
	535	return -ENOMEM;
	536
c7754d46 DM	537	minor = 1;
	538	if (sun4v_hvapi_register(HV_GRP_CORE, 1, &minor) == 0 &&
	539	minor >= 1) {
	540	err = -ENOMEM;
	541	con_write_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
	542	if (!con_write_page)
	543	goto out_free_port;
	544
	545	con_read_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
	546	if (!con_read_page)
	547	goto out_free_con_write_page;
	548
	549	sunhv_console.write = sunhv_console_write_paged;
	550	sunhv_ops = &bywrite_ops;
	551	}
	552
93872ba2	553	sunhv_port = port;
db33f9bc	554
02fd473b DM	555	port->line = 0;
	556	port->ops = &sunhv_pops;
	557	port->type = PORT_SUNHV;
	558	port->uartclk = ( 29491200 / 16 ); /* arbitrary */
	559
db33f9bc DM	560	port->membase = (unsigned char __iomem *) __pa(port);
db33f9bc DM	561
1636f8ac	562	port->irq = op->archdata.irqs[0];
93872ba2 DM	563
93872ba2 DM	564	port->dev = &op->dev;
02fd473b	565
58d784a5	566	err = sunserial_register_minors(&sunhv_reg, 1);
93872ba2	567	if (err)
c7754d46	568	goto out_free_con_read_page;
02fd473b	569
61c7a080	570	sunserial_console_match(&sunhv_console, op->dev.of_node,
457931de	571	&sunhv_reg, port->line, false);
d5a2aa24	572
93872ba2 DM	573	err = uart_add_one_port(&sunhv_reg, port);
	574	if (err)
	575	goto out_unregister_driver;
02fd473b	576
93872ba2 DM	577	err = request_irq(port->irq, sunhv_interrupt, 0, "hvcons", port);
	578	if (err)
	579	goto out_remove_port;
db33f9bc	580
696faedd	581	platform_set_drvdata(op, port);
02fd473b DM	582
02fd473b DM	583	return 0;
93872ba2 DM	584
	585	out_remove_port:
	586	uart_remove_one_port(&sunhv_reg, port);
	587
	588	out_unregister_driver:
58d784a5	589	sunserial_unregister_minors(&sunhv_reg, 1);
93872ba2	590
c7754d46 DM	591	out_free_con_read_page:
	592	kfree(con_read_page);
	593
	594	out_free_con_write_page:
	595	kfree(con_write_page);
	596
93872ba2 DM	597	out_free_port:
	598	kfree(port);
	599	sunhv_port = NULL;
	600	return err;
02fd473b DM	601	}
02fd473b DM	602
ae8d8a14	603	static int hv_remove(struct platform_device *dev)
02fd473b	604	{
696faedd	605	struct uart_port *port = platform_get_drvdata(dev);
02fd473b	606
db33f9bc DM	607	free_irq(port->irq, port);
db33f9bc DM	608
02fd473b	609	uart_remove_one_port(&sunhv_reg, port);
02fd473b	610
58d784a5	611	sunserial_unregister_minors(&sunhv_reg, 1);
fbb7d2e3 SJ	612	kfree(con_read_page);
fbb7d2e3 SJ	613	kfree(con_write_page);
93872ba2	614	kfree(port);
02fd473b	615	sunhv_port = NULL;
93872ba2	616
93872ba2 DM	617	return 0;
	618	}
	619
fd098316	620	static const struct of_device_id hv_match[] = {
93872ba2 DM	621	{
	622	.name = "console",
	623	.compatible = "qcn",
	624	},
7a05b591 DM	625	{
	626	.name = "console",
	627	.compatible = "SUNW,sun4v-console",
	628	},
93872ba2 DM	629	{},
93872ba2 DM	630	};
93872ba2	631
793218df	632	static struct platform_driver hv_driver = {
4018294b GL	633	.driver = {
4018294b GL	634	.name = "hv",
4018294b GL	635	.of_match_table = hv_match,
4018294b GL	636	},
93872ba2	637	.probe = hv_probe,
2d47b716	638	.remove = hv_remove,
93872ba2 DM	639	};
	640
	641	static int __init sunhv_init(void)
	642	{
	643	if (tlb_type != hypervisor)
	644	return -ENODEV;
	645
793218df	646	return platform_driver_register(&hv_driver);
93872ba2	647	}
4fef5351	648	device_initcall(sunhv_init);
93872ba2	649
4fef5351	650	#if 0 /* ...def MODULE ; never supported as such */
02fd473b	651	MODULE_AUTHOR("David S. Miller");
93872ba2 DM	652	MODULE_DESCRIPTION("SUN4V Hypervisor console driver");
93872ba2 DM	653	MODULE_VERSION("2.0");
02fd473b	654	MODULE_LICENSE("GPL");
4fef5351	655	#endif