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