From c7754d465b1feade85b5f1c4492781a30f6652a2 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Tue, 15 May 2007 17:03:54 -0700 Subject: [SPARC64]: Add hypervisor API negotiation and fix console bugs. Hypervisor interfaces need to be negotiated in order to use some API calls reliably. So add a small set of interfaces to request API versions and query current settings. This allows us to fix some bugs in the hypervisor console: 1) If we can negotiate API group CORE of at least major 1 minor 1 we can use con_read and con_write which can improve console performance quite a bit. 2) When we do a console write request, we should hold the spinlock around the whole request, not a byte at a time. What would happen is that it's easy for output from different cpus to get mixed with each other. 3) Use consistent udelay() based polling, udelay(1) each loop with a limit of 1000 polls to handle stuck hypervisor console. Signed-off-by: David S. Miller --- drivers/serial/sunhv.c | 276 ++++++++++++++++++++++++++++++++++++------------- 1 file changed, 205 insertions(+), 71 deletions(-) (limited to 'drivers') diff --git a/drivers/serial/sunhv.c b/drivers/serial/sunhv.c index c3a6bd2e795..96557e6dba6 100644 --- a/drivers/serial/sunhv.c +++ b/drivers/serial/sunhv.c @@ -1,6 +1,6 @@ /* sunhv.c: Serial driver for SUN4V hypervisor console. * - * Copyright (C) 2006 David S. Miller (davem@davemloft.net) + * Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net) */ #include @@ -35,57 +35,51 @@ #define CON_BREAK ((long)-1) #define CON_HUP ((long)-2) -static inline long hypervisor_con_getchar(long *status) -{ - register unsigned long func asm("%o5"); - register unsigned long arg0 asm("%o0"); - register unsigned long arg1 asm("%o1"); - - func = HV_FAST_CONS_GETCHAR; - arg0 = 0; - arg1 = 0; - __asm__ __volatile__("ta %6" - : "=&r" (func), "=&r" (arg0), "=&r" (arg1) - : "0" (func), "1" (arg0), "2" (arg1), - "i" (HV_FAST_TRAP)); +#define IGNORE_BREAK 0x1 +#define IGNORE_ALL 0x2 - *status = arg0; +static char *con_write_page; +static char *con_read_page; - return (long) arg1; -} +static int hung_up = 0; -static inline long hypervisor_con_putchar(long ch) +static void transmit_chars_putchar(struct uart_port *port, struct circ_buf *xmit) { - register unsigned long func asm("%o5"); - register unsigned long arg0 asm("%o0"); + while (!uart_circ_empty(xmit)) { + long status = sun4v_con_putchar(xmit->buf[xmit->tail]); - func = HV_FAST_CONS_PUTCHAR; - arg0 = ch; - __asm__ __volatile__("ta %4" - : "=&r" (func), "=&r" (arg0) - : "0" (func), "1" (arg0), "i" (HV_FAST_TRAP)); + if (status != HV_EOK) + break; - return (long) arg0; + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + } } -#define IGNORE_BREAK 0x1 -#define IGNORE_ALL 0x2 +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; -static int hung_up = 0; + 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 struct tty_struct *receive_chars(struct uart_port *port) +static int receive_chars_getchar(struct uart_port *port, struct tty_struct *tty) { - struct tty_struct *tty = NULL; int saw_console_brk = 0; int limit = 10000; - if (port->info != NULL) /* Unopened serial console */ - tty = port->info->tty; - while (limit-- > 0) { long status; - long c = hypervisor_con_getchar(&status); - unsigned char flag; + long c = sun4v_con_getchar(&status); if (status == HV_EWOULDBLOCK) break; @@ -110,27 +104,90 @@ static struct tty_struct *receive_chars(struct uart_port *port) continue; } - flag = TTY_NORMAL; port->icount.rx++; - if (c == CON_BREAK) { - port->icount.brk++; - if (uart_handle_break(port)) - continue; - flag = TTY_BREAK; - } if (uart_handle_sysrq_char(port, c)) continue; - if ((port->ignore_status_mask & IGNORE_ALL) || - ((port->ignore_status_mask & IGNORE_BREAK) && - (c == CON_BREAK))) + 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; - tty_insert_flip_char(tty, c, flag); + port->icount.rx += bytes_read; + + tty_insert_flip_string(tty, con_read_page, bytes_read); } - if (saw_console_brk) + 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->info != NULL) /* Unopened serial console */ + tty = port->info->tty; + + if (sunhv_ops->receive_chars(port, tty)) sun_do_break(); return tty; @@ -147,15 +204,7 @@ static void transmit_chars(struct uart_port *port) if (uart_circ_empty(xmit) || uart_tx_stopped(port)) return; - while (!uart_circ_empty(xmit)) { - long status = hypervisor_con_putchar(xmit->buf[xmit->tail]); - - if (status != HV_EOK) - break; - - xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); - port->icount.tx++; - } + sunhv_ops->transmit_chars(port, xmit); if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) uart_write_wakeup(port); @@ -212,7 +261,7 @@ static void sunhv_start_tx(struct uart_port *port) struct circ_buf *xmit = &port->info->xmit; while (!uart_circ_empty(xmit)) { - long status = hypervisor_con_putchar(xmit->buf[xmit->tail]); + long status = sun4v_con_putchar(xmit->buf[xmit->tail]); if (status != HV_EOK) break; @@ -231,9 +280,10 @@ static void sunhv_send_xchar(struct uart_port *port, char ch) spin_lock_irqsave(&port->lock, flags); while (limit-- > 0) { - long status = hypervisor_con_putchar(ch); + long status = sun4v_con_putchar(ch); if (status == HV_EOK) break; + udelay(1); } spin_unlock_irqrestore(&port->lock, flags); @@ -254,15 +304,15 @@ static void sunhv_break_ctl(struct uart_port *port, int break_state) { if (break_state) { unsigned long flags; - int limit = 1000000; + int limit = 10000; spin_lock_irqsave(&port->lock, flags); while (limit-- > 0) { - long status = hypervisor_con_putchar(CON_BREAK); + long status = sun4v_con_putchar(CON_BREAK); if (status == HV_EOK) break; - udelay(2); + udelay(1); } spin_unlock_irqrestore(&port->lock, flags); @@ -359,38 +409,99 @@ static struct uart_driver sunhv_reg = { static struct uart_port *sunhv_port; -static inline void sunhv_console_putchar(struct uart_port *port, char c) +/* 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 limit = 1000000; 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; + } + } + 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 = hypervisor_con_putchar(c); + long status = sun4v_con_putchar(c); if (status == HV_EOK) break; - udelay(2); + udelay(1); } - - spin_unlock_irqrestore(&port->lock, flags); } -static void sunhv_console_write(struct console *con, const char *s, unsigned n) +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; + 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++); } + spin_unlock_irqrestore(&port->lock, flags); } static struct console sunhv_console = { .name = "ttyHV", - .write = sunhv_console_write, + .write = sunhv_console_write_bychar, .device = uart_console_device, .flags = CON_PRINTBUFFER, .index = -1, @@ -410,6 +521,7 @@ static inline struct console *SUNHV_CONSOLE(void) static int __devinit hv_probe(struct of_device *op, const struct of_device_id *match) { struct uart_port *port; + unsigned long minor; int err; if (op->irqs[0] == 0xffffffff) @@ -419,6 +531,22 @@ static int __devinit hv_probe(struct of_device *op, const struct of_device_id *m 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; @@ -437,7 +565,7 @@ static int __devinit hv_probe(struct of_device *op, const struct of_device_id *m err = uart_register_driver(&sunhv_reg); if (err) - goto out_free_port; + goto out_free_con_read_page; sunhv_reg.tty_driver->name_base = sunhv_reg.minor - 64; sunserial_current_minor += 1; @@ -463,6 +591,12 @@ out_unregister_driver: sunserial_current_minor -= 1; uart_unregister_driver(&sunhv_reg); +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; -- cgit v1.2.3