1 files changed, 661 insertions, 0 deletions

diff --git a/drivers/tty/serial/sunhv.c b/drivers/tty/serial/sunhv.c
new file mode 100644
index 000000000000..c9014868297d
--- /dev/null
+++ b/drivers/tty/serial/sunhv.c
@@ -0,0 +1,661 @@
+/* sunhv.c: Serial driver for SUN4V hypervisor console.
+ *
+ * Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net)
+ */
+
+#include <linux/module.h>
+#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>
+
+#if defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/serial_core.h>
+
+#include "suncore.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, struct tty_struct *tty)
+{
+        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 (tty == NULL) {
+                        uart_handle_sysrq_char(port, c);
+                        continue;
+                }
+
+                port->icount.rx++;
+
+                if (uart_handle_sysrq_char(port, c))
+                        continue;
+
+                tty_insert_flip_char(tty, c, TTY_NORMAL);
+        }
+
+        return saw_console_brk;
+}
+
+static int receive_chars_read(struct uart_port *port, struct tty_struct *tty)
+{
+        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);
+                }
+
+                for (i = 0; i < bytes_read; i++)
+                        uart_handle_sysrq_char(port, con_read_page[i]);
+
+                if (tty == NULL)
+                        continue;
+
+                port->icount.rx += bytes_read;
+
+                tty_insert_flip_string(tty, 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, struct tty_struct *tty);
+};
+
+static struct sunhv_ops bychar_ops = {
+        .transmit_chars = transmit_chars_putchar,
+        .receive_chars = receive_chars_getchar,
+};
+
+static struct sunhv_ops bywrite_ops = {
+        .transmit_chars = transmit_chars_write,
+        .receive_chars = receive_chars_read,
+};
+
+static struct sunhv_ops *sunhv_ops = &bychar_ops;
+
+static struct tty_struct *receive_chars(struct uart_port *port)
+{
+        struct tty_struct *tty = NULL;
+
+        if (port->state != NULL)                /* Unopened serial console */
+                tty = port->state->port.tty;
+
+        if (sunhv_ops->receive_chars(port, tty))
+                sun_do_break();
+
+        return tty;
+}
+
+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_struct *tty;
+        unsigned long flags;
+
+        spin_lock_irqsave(&port->lock, flags);
+        tty = receive_chars(port);
+        transmit_chars(port);
+        spin_unlock_irqrestore(&port->lock, flags);
+
+        if (tty)
+                tty_flip_buffer_push(tty);
+
+        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;
+
+        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 held by caller.  */
+static void sunhv_enable_ms(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 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,
+        .enable_ms      = sunhv_enable_ms,
+        .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;
+
+/* 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;
+
+        local_irq_save(flags);
+        if (port->sysrq) {
+                locked = 0;
+        } else if (oops_in_progress) {
+                locked = spin_trylock(&port->lock);
+        } else
+                spin_lock(&port->lock);
+
+        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(&port->lock);
+        local_irq_restore(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;
+
+        local_irq_save(flags);
+        if (port->sysrq) {
+                locked = 0;
+        } else if (oops_in_progress) {
+                locked = spin_trylock(&port->lock);
+        } else
+                spin_lock(&port->lock);
+
+        for (i = 0; i < n; i++) {
+                if (*s == '\n')
+                        sunhv_console_putchar(port, '\r');
+                sunhv_console_putchar(port, *s++);
+        }
+
+        if (locked)
+                spin_unlock(&port->lock);
+        local_irq_restore(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 __devinit hv_probe(struct platform_device *op, const struct of_device_id *match)
+{
+        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;
+
+        dev_set_drvdata(&op->dev, 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 __devexit hv_remove(struct platform_device *dev)
+{
+        struct uart_port *port = dev_get_drvdata(&dev->dev);
+
+        free_irq(port->irq, port);
+
+        uart_remove_one_port(&sunhv_reg, port);
+
+        sunserial_unregister_minors(&sunhv_reg, 1);
+
+        kfree(port);
+        sunhv_port = NULL;
+
+        dev_set_drvdata(&dev->dev, NULL);
+
+        return 0;
+}
+
+static const struct of_device_id hv_match[] = {
+        {
+                .name = "console",
+                .compatible = "qcn",
+        },
+        {
+                .name = "console",
+                .compatible = "SUNW,sun4v-console",
+        },
+        {},
+};
+MODULE_DEVICE_TABLE(of, hv_match);
+
+static struct of_platform_driver hv_driver = {
+        .driver = {
+                .name = "hv",
+                .owner = THIS_MODULE,
+                .of_match_table = hv_match,
+        },
+        .probe          = hv_probe,
+        .remove         = __devexit_p(hv_remove),
+};
+
+static int __init sunhv_init(void)
+{
+        if (tlb_type != hypervisor)
+                return -ENODEV;
+
+        return of_register_platform_driver(&hv_driver);
+}
+
+static void __exit sunhv_exit(void)
+{
+        of_unregister_platform_driver(&hv_driver);
+}
+
+module_init(sunhv_init);
+module_exit(sunhv_exit);
+
+MODULE_AUTHOR("David S. Miller");
+MODULE_DESCRIPTION("SUN4V Hypervisor console driver");
+MODULE_VERSION("2.0");
+MODULE_LICENSE("GPL");