diff options
| -rw-r--r-- | drivers/tty/hvc/hvc_vio.c | 58 |
1 files changed, 37 insertions, 21 deletions
diff --git a/drivers/tty/hvc/hvc_vio.c b/drivers/tty/hvc/hvc_vio.c index 710c06ca70f4..ae659a4596b0 100644 --- a/drivers/tty/hvc/hvc_vio.c +++ b/drivers/tty/hvc/hvc_vio.c @@ -71,41 +71,53 @@ struct hvterm_priv { u32 termno; /* HV term number */ hv_protocol_t proto; /* Raw data or HVSI packets */ struct hvsi_priv hvsi; /* HVSI specific data */ + spinlock_t buf_lock; + char buf[SIZE_VIO_GET_CHARS]; + int left; + int offset; }; static struct hvterm_priv *hvterm_privs[MAX_NR_HVC_CONSOLES]; - /* For early boot console */ static struct hvterm_priv hvterm_priv0; static int hvterm_raw_get_chars(uint32_t vtermno, char *buf, int count) { struct hvterm_priv *pv = hvterm_privs[vtermno]; - unsigned long got, i; + unsigned long i; + unsigned long flags; + int got; if (WARN_ON(!pv)) return 0; - /* - * Vio firmware will read up to SIZE_VIO_GET_CHARS at its own discretion - * so we play safe and avoid the situation where got > count which could - * overload the flip buffer. - */ - if (count < SIZE_VIO_GET_CHARS) - return -EAGAIN; - - got = hvc_get_chars(pv->termno, buf, count); - - /* - * Work around a HV bug where it gives us a null - * after every \r. -- paulus - */ - for (i = 1; i < got; ++i) { - if (buf[i] == 0 && buf[i-1] == '\r') { - --got; - if (i < got) - memmove(&buf[i], &buf[i+1], got - i); + spin_lock_irqsave(&pv->buf_lock, flags); + + if (pv->left == 0) { + pv->offset = 0; + pv->left = hvc_get_chars(pv->termno, pv->buf, count); + + /* + * Work around a HV bug where it gives us a null + * after every \r. -- paulus + */ + for (i = 1; i < pv->left; ++i) { + if (pv->buf[i] == 0 && pv->buf[i-1] == '\r') { + --pv->left; + if (i < pv->left) { + memmove(&pv->buf[i], &pv->buf[i+1], + pv->left - i); + } + } } } + + got = min(count, pv->left); + memcpy(buf, &pv->buf[pv->offset], got); + pv->offset += got; + pv->left -= got; + + spin_unlock_irqrestore(&pv->buf_lock, flags); + return got; } @@ -266,6 +278,7 @@ static int __devinit hvc_vio_probe(struct vio_dev *vdev, return -ENOMEM; pv->termno = vdev->unit_address; pv->proto = proto; + spin_lock_init(&pv->buf_lock); hvterm_privs[termno] = pv; hvsilib_init(&pv->hvsi, hvc_get_chars, hvc_put_chars, pv->termno, 0); @@ -406,6 +419,7 @@ void __init hvc_vio_init_early(void) if (termno == NULL) goto out; hvterm_priv0.termno = *termno; + spin_lock_init(&hvterm_priv0.buf_lock); hvterm_privs[0] = &hvterm_priv0; /* Check the protocol */ @@ -447,6 +461,7 @@ void __init udbg_init_debug_lpar(void) hvterm_privs[0] = &hvterm_priv0; hvterm_priv0.termno = 0; hvterm_priv0.proto = HV_PROTOCOL_RAW; + spin_lock_init(&hvterm_priv0.buf_lock) udbg_putc = udbg_hvc_putc; udbg_getc = udbg_hvc_getc; udbg_getc_poll = udbg_hvc_getc_poll; @@ -459,6 +474,7 @@ void __init udbg_init_debug_lpar_hvsi(void) hvterm_privs[0] = &hvterm_priv0; hvterm_priv0.termno = CONFIG_PPC_EARLY_DEBUG_HVSI_VTERMNO; hvterm_priv0.proto = HV_PROTOCOL_HVSI; + spin_lock_init(&hvterm_priv0.buf_lock) udbg_putc = udbg_hvc_putc; udbg_getc = udbg_hvc_getc; udbg_getc_poll = udbg_hvc_getc_poll; |