From a9bf5c8a271b9a954709b7ada1bd258f5cadf7ff Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 1 May 2018 00:55:53 +1000 Subject: tty: hvc: use mutex instead of spinlock for hvc_structs lock This allows hvc operations to sleep under the lock. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- drivers/tty/hvc/hvc_console.c | 23 +++++++++++------------ 1 file changed, 11 insertions(+), 12 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index 7709fcc707f4..fddb63322c67 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -73,7 +73,7 @@ static LIST_HEAD(hvc_structs); * Protect the list of hvc_struct instances from inserts and removals during * list traversal. */ -static DEFINE_SPINLOCK(hvc_structs_lock); +static DEFINE_MUTEX(hvc_structs_mutex); /* * This value is used to assign a tty->index value to a hvc_struct based @@ -83,7 +83,7 @@ static DEFINE_SPINLOCK(hvc_structs_lock); static int last_hvc = -1; /* - * Do not call this function with either the hvc_structs_lock or the hvc_struct + * Do not call this function with either the hvc_structs_mutex or the hvc_struct * lock held. If successful, this function increments the kref reference * count against the target hvc_struct so it should be released when finished. */ @@ -92,25 +92,24 @@ static struct hvc_struct *hvc_get_by_index(int index) struct hvc_struct *hp; unsigned long flags; - spin_lock(&hvc_structs_lock); + mutex_lock(&hvc_structs_mutex); list_for_each_entry(hp, &hvc_structs, next) { spin_lock_irqsave(&hp->lock, flags); if (hp->index == index) { tty_port_get(&hp->port); spin_unlock_irqrestore(&hp->lock, flags); - spin_unlock(&hvc_structs_lock); + mutex_unlock(&hvc_structs_mutex); return hp; } spin_unlock_irqrestore(&hp->lock, flags); } hp = NULL; + mutex_unlock(&hvc_structs_mutex); - spin_unlock(&hvc_structs_lock); return hp; } - /* * Initial console vtermnos for console API usage prior to full console * initialization. Any vty adapter outside this range will not have usable @@ -224,13 +223,13 @@ static void hvc_port_destruct(struct tty_port *port) struct hvc_struct *hp = container_of(port, struct hvc_struct, port); unsigned long flags; - spin_lock(&hvc_structs_lock); + mutex_lock(&hvc_structs_mutex); spin_lock_irqsave(&hp->lock, flags); list_del(&(hp->next)); spin_unlock_irqrestore(&hp->lock, flags); - spin_unlock(&hvc_structs_lock); + mutex_unlock(&hvc_structs_mutex); kfree(hp); } @@ -733,11 +732,11 @@ static int khvcd(void *unused) try_to_freeze(); wmb(); if (!cpus_are_in_xmon()) { - spin_lock(&hvc_structs_lock); + mutex_lock(&hvc_structs_mutex); list_for_each_entry(hp, &hvc_structs, next) { poll_mask |= hvc_poll(hp); } - spin_unlock(&hvc_structs_lock); + mutex_unlock(&hvc_structs_mutex); } else poll_mask |= HVC_POLL_READ; if (hvc_kicked) @@ -871,7 +870,7 @@ struct hvc_struct *hvc_alloc(uint32_t vtermno, int data, INIT_WORK(&hp->tty_resize, hvc_set_winsz); spin_lock_init(&hp->lock); - spin_lock(&hvc_structs_lock); + mutex_lock(&hvc_structs_mutex); /* * find index to use: @@ -891,7 +890,7 @@ struct hvc_struct *hvc_alloc(uint32_t vtermno, int data, vtermnos[i] = vtermno; list_add_tail(&(hp->next), &hvc_structs); - spin_unlock(&hvc_structs_lock); + mutex_unlock(&hvc_structs_mutex); /* check if we need to re-register the kernel console */ hvc_check_console(i); -- cgit v1.2.3-70-g09d2 From ec97eaad1383ab2500fcf9a07ade6044fbcc67f5 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 1 May 2018 00:55:54 +1000 Subject: tty: hvc: hvc_poll() break hv read loop Avoid looping with the spinlock held while there is read data being returned from the hv driver. Instead note if the entire size returned by tty_buffer_request_room was read, and request another read poll. This limits the critical section lengths, and provides more even service to other consoles in case there is a pathological condition. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- drivers/tty/hvc/hvc_console.c | 88 ++++++++++++++++++++++--------------------- 1 file changed, 45 insertions(+), 43 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index fddb63322c67..745ac220fce8 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -592,7 +592,7 @@ static u32 timeout = MIN_TIMEOUT; int hvc_poll(struct hvc_struct *hp) { struct tty_struct *tty; - int i, n, poll_mask = 0; + int i, n, count, poll_mask = 0; char buf[N_INBUF] __ALIGNED__; unsigned long flags; int read_total = 0; @@ -618,7 +618,7 @@ int hvc_poll(struct hvc_struct *hp) /* Now check if we can get data (are we throttled ?) */ if (tty_throttled(tty)) - goto throttled; + goto out; /* If we aren't notifier driven and aren't throttled, we always * request a reschedule @@ -627,56 +627,58 @@ int hvc_poll(struct hvc_struct *hp) poll_mask |= HVC_POLL_READ; /* Read data if any */ - for (;;) { - int count = tty_buffer_request_room(&hp->port, N_INBUF); - /* If flip is full, just reschedule a later read */ - if (count == 0) { + count = tty_buffer_request_room(&hp->port, N_INBUF); + + /* If flip is full, just reschedule a later read */ + if (count == 0) { + poll_mask |= HVC_POLL_READ; + goto out; + } + + n = hp->ops->get_chars(hp->vtermno, buf, count); + if (n <= 0) { + /* Hangup the tty when disconnected from host */ + if (n == -EPIPE) { + spin_unlock_irqrestore(&hp->lock, flags); + tty_hangup(tty); + spin_lock_irqsave(&hp->lock, flags); + } else if ( n == -EAGAIN ) { + /* + * Some back-ends can only ensure a certain min + * num of bytes read, which may be > 'count'. + * Let the tty clear the flip buff to make room. + */ poll_mask |= HVC_POLL_READ; - break; } + goto out; + } - n = hp->ops->get_chars(hp->vtermno, buf, count); - if (n <= 0) { - /* Hangup the tty when disconnected from host */ - if (n == -EPIPE) { - spin_unlock_irqrestore(&hp->lock, flags); - tty_hangup(tty); - spin_lock_irqsave(&hp->lock, flags); - } else if ( n == -EAGAIN ) { - /* - * Some back-ends can only ensure a certain min - * num of bytes read, which may be > 'count'. - * Let the tty clear the flip buff to make room. - */ - poll_mask |= HVC_POLL_READ; - } - break; - } - for (i = 0; i < n; ++i) { + for (i = 0; i < n; ++i) { #ifdef CONFIG_MAGIC_SYSRQ - if (hp->index == hvc_console.index) { - /* Handle the SysRq Hack */ - /* XXX should support a sequence */ - if (buf[i] == '\x0f') { /* ^O */ - /* if ^O is pressed again, reset - * sysrq_pressed and flip ^O char */ - sysrq_pressed = !sysrq_pressed; - if (sysrq_pressed) - continue; - } else if (sysrq_pressed) { - handle_sysrq(buf[i]); - sysrq_pressed = 0; + if (hp->index == hvc_console.index) { + /* Handle the SysRq Hack */ + /* XXX should support a sequence */ + if (buf[i] == '\x0f') { /* ^O */ + /* if ^O is pressed again, reset + * sysrq_pressed and flip ^O char */ + sysrq_pressed = !sysrq_pressed; + if (sysrq_pressed) continue; - } + } else if (sysrq_pressed) { + handle_sysrq(buf[i]); + sysrq_pressed = 0; + continue; } -#endif /* CONFIG_MAGIC_SYSRQ */ - tty_insert_flip_char(&hp->port, buf[i], 0); } - - read_total += n; +#endif /* CONFIG_MAGIC_SYSRQ */ + tty_insert_flip_char(&hp->port, buf[i], 0); } - throttled: + if (n == count) + poll_mask |= HVC_POLL_READ; + read_total = n; + + out: /* Wakeup write queue if necessary */ if (hp->do_wakeup) { hp->do_wakeup = 0; -- cgit v1.2.3-70-g09d2 From cfb5946b55f1dfd19e042feae1fbff6041e25a98 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 1 May 2018 00:55:55 +1000 Subject: tty: hvc: hvc_poll() may sleep Introduce points where hvc_poll drops the lock, enables interrupts, and reschedules. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- drivers/tty/hvc/hvc_console.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index 745ac220fce8..2abfc0b15fbb 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -589,7 +589,7 @@ static u32 timeout = MIN_TIMEOUT; #define HVC_POLL_READ 0x00000001 #define HVC_POLL_WRITE 0x00000002 -int hvc_poll(struct hvc_struct *hp) +static int __hvc_poll(struct hvc_struct *hp, bool may_sleep) { struct tty_struct *tty; int i, n, count, poll_mask = 0; @@ -611,6 +611,12 @@ int hvc_poll(struct hvc_struct *hp) timeout = (written_total) ? 0 : MIN_TIMEOUT; } + if (may_sleep) { + spin_unlock_irqrestore(&hp->lock, flags); + cond_resched(); + spin_lock_irqsave(&hp->lock, flags); + } + /* No tty attached, just skip */ tty = tty_port_tty_get(&hp->port); if (tty == NULL) @@ -698,6 +704,11 @@ int hvc_poll(struct hvc_struct *hp) return poll_mask; } + +int hvc_poll(struct hvc_struct *hp) +{ + return __hvc_poll(hp, false); +} EXPORT_SYMBOL_GPL(hvc_poll); /** @@ -736,7 +747,8 @@ static int khvcd(void *unused) if (!cpus_are_in_xmon()) { mutex_lock(&hvc_structs_mutex); list_for_each_entry(hp, &hvc_structs, next) { - poll_mask |= hvc_poll(hp); + poll_mask |= __hvc_poll(hp, true); + cond_resched(); } mutex_unlock(&hvc_structs_mutex); } else -- cgit v1.2.3-70-g09d2 From 550ddadcc7580ec2a6c22d4ed04291bc6e2428fb Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 1 May 2018 00:55:56 +1000 Subject: tty: hvc: hvc_write() may sleep Rework the hvc_write loop to drop and re-take the spinlock on each iteration, add a cond_resched. Don't bother with an initial hvc_push initially, which makes the logic simpler -- just do a hvc_push on each time around the loop. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- drivers/tty/hvc/hvc_console.c | 36 +++++++++++++++++++++--------------- 1 file changed, 21 insertions(+), 15 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index 2abfc0b15fbb..6131d5084c42 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -493,23 +493,29 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count if (hp->port.count <= 0) return -EIO; - spin_lock_irqsave(&hp->lock, flags); + while (count > 0) { + spin_lock_irqsave(&hp->lock, flags); - /* Push pending writes */ - if (hp->n_outbuf > 0) - hvc_push(hp); - - while (count > 0 && (rsize = hp->outbuf_size - hp->n_outbuf) > 0) { - if (rsize > count) - rsize = count; - memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); - count -= rsize; - buf += rsize; - hp->n_outbuf += rsize; - written += rsize; - hvc_push(hp); + rsize = hp->outbuf_size - hp->n_outbuf; + + if (rsize) { + if (rsize > count) + rsize = count; + memcpy(hp->outbuf + hp->n_outbuf, buf, rsize); + count -= rsize; + buf += rsize; + hp->n_outbuf += rsize; + written += rsize; + } + + if (hp->n_outbuf > 0) + hvc_push(hp); + + spin_unlock_irqrestore(&hp->lock, flags); + + if (count) + cond_resched(); } - spin_unlock_irqrestore(&hp->lock, flags); /* * Racy, but harmless, kick thread if there is still pending data. -- cgit v1.2.3-70-g09d2 From 9f65b81f36e31563c5a5e4df3b3b8bc7550b6030 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 1 May 2018 00:55:57 +1000 Subject: tty: hvc: introduce the hv_ops.flush operation for hvc drivers Use .flush to wait for drivers to flush their console outside of the spinlock, to reduce lock/irq latencies. Flush the hvc console driver after each write, which can help messages make it out to the console after a crash. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- drivers/tty/hvc/hvc_console.c | 35 +++++++++++++++++++++++++++++++++-- drivers/tty/hvc/hvc_console.h | 1 + 2 files changed, 34 insertions(+), 2 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/hvc/hvc_console.c b/drivers/tty/hvc/hvc_console.c index 6131d5084c42..5414c4a87bea 100644 --- a/drivers/tty/hvc/hvc_console.c +++ b/drivers/tty/hvc/hvc_console.c @@ -110,6 +110,29 @@ static struct hvc_struct *hvc_get_by_index(int index) return hp; } +static int __hvc_flush(const struct hv_ops *ops, uint32_t vtermno, bool wait) +{ + if (wait) + might_sleep(); + + if (ops->flush) + return ops->flush(vtermno, wait); + return 0; +} + +static int hvc_console_flush(const struct hv_ops *ops, uint32_t vtermno) +{ + return __hvc_flush(ops, vtermno, false); +} + +/* + * Wait for the console to flush before writing more to it. This sleeps. + */ +static int hvc_flush(struct hvc_struct *hp) +{ + return __hvc_flush(hp->ops, hp->vtermno, true); +} + /* * Initial console vtermnos for console API usage prior to full console * initialization. Any vty adapter outside this range will not have usable @@ -155,8 +178,12 @@ static void hvc_console_print(struct console *co, const char *b, if (r <= 0) { /* throw away characters on error * but spin in case of -EAGAIN */ - if (r != -EAGAIN) + if (r != -EAGAIN) { i = 0; + } else { + hvc_console_flush(cons_ops[index], + vtermnos[index]); + } } else if (r > 0) { i -= r; if (i > 0) @@ -164,6 +191,7 @@ static void hvc_console_print(struct console *co, const char *b, } } } + hvc_console_flush(cons_ops[index], vtermnos[index]); } static struct tty_driver *hvc_console_device(struct console *c, int *index) @@ -513,8 +541,11 @@ static int hvc_write(struct tty_struct *tty, const unsigned char *buf, int count spin_unlock_irqrestore(&hp->lock, flags); - if (count) + if (count) { + if (hp->n_outbuf > 0) + hvc_flush(hp); cond_resched(); + } } /* diff --git a/drivers/tty/hvc/hvc_console.h b/drivers/tty/hvc/hvc_console.h index ea63090e013f..e9319954c832 100644 --- a/drivers/tty/hvc/hvc_console.h +++ b/drivers/tty/hvc/hvc_console.h @@ -54,6 +54,7 @@ struct hvc_struct { struct hv_ops { int (*get_chars)(uint32_t vtermno, char *buf, int count); int (*put_chars)(uint32_t vtermno, const char *buf, int count); + int (*flush)(uint32_t vtermno, bool wait); /* Callbacks for notification. Called in open, close and hangup */ int (*notifier_add)(struct hvc_struct *hp, int irq); -- cgit v1.2.3-70-g09d2 From ac4ac788fdadc6b703ff3322de07dee442e08e1c Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 1 May 2018 00:55:50 +1000 Subject: powerpc/powernv: move opal console flushing to udbg OPAL console writes do not have to synchronously flush firmware / hardware buffers unless they are going through the udbg path. Remove the unconditional flushing from opal_put_chars. Flush if there was no space in the buffer as an optimisation (callers loop waiting for success in that case). udbg flushing is moved to udbg_opal_putc. Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/powernv/opal.c | 12 +++++++----- drivers/tty/hvc/hvc_opal.c | 5 +++++ 2 files changed, 12 insertions(+), 5 deletions(-) (limited to 'drivers/tty') diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index e18472757617..cf02e602237a 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -400,12 +400,14 @@ int opal_put_chars(uint32_t vtermno, const char *data, int total_len) out: spin_unlock_irqrestore(&opal_write_lock, flags); - /* This is a bit nasty but we need that for the console to - * flush when there aren't any interrupts. We will clean - * things a bit later to limit that to synchronous path - * such as the kernel console and xmon/udbg + /* In the -EAGAIN case, callers loop, so we have to flush the console + * here in case they have interrupts off (and we don't want to wait + * for async flushing if we can make immediate progress here). If + * necessary the API could be made entirely non-flushing if the + * callers had a ->flush API to use. */ - opal_flush_console(vtermno); + if (written == -EAGAIN) + opal_flush_console(vtermno); return written; } diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c index 9645c0062a90..958c61c8f35a 100644 --- a/drivers/tty/hvc/hvc_opal.c +++ b/drivers/tty/hvc/hvc_opal.c @@ -275,6 +275,11 @@ static void udbg_opal_putc(char c) count = hvc_opal_hvsi_put_chars(termno, &c, 1); break; } + + /* This is needed for the cosole to flush + * when there aren't any interrupts. + */ + opal_flush_console(termno); } while(count == 0 || count == -EAGAIN); } -- cgit v1.2.3-70-g09d2 From 17cc1dd4924391b54fb179d0868b89dc96f2ee80 Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 1 May 2018 00:55:51 +1000 Subject: powerpc/powernv: implement opal_put_chars_atomic The RAW console does not need writes to be atomic, so relax opal_put_chars to be able to do partial writes, and implement an _atomic variant which does not take a spinlock. This API is used in xmon, so the less locking that is used, the better chance there is that a crash can be debugged. Cc: Benjamin Herrenschmidt Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/opal.h | 1 + arch/powerpc/platforms/powernv/opal.c | 37 +++++++++++++++++++++++++---------- drivers/tty/hvc/hvc_opal.c | 18 ++++++++++++----- 3 files changed, 41 insertions(+), 15 deletions(-) (limited to 'drivers/tty') diff --git a/arch/powerpc/include/asm/opal.h b/arch/powerpc/include/asm/opal.h index 33ab95a4ac0f..cd1acc8be8ee 100644 --- a/arch/powerpc/include/asm/opal.h +++ b/arch/powerpc/include/asm/opal.h @@ -305,6 +305,7 @@ extern void opal_configure_cores(void); extern int opal_get_chars(uint32_t vtermno, char *buf, int count); extern int opal_put_chars(uint32_t vtermno, const char *buf, int total_len); +extern int opal_put_chars_atomic(uint32_t vtermno, const char *buf, int total_len); extern int opal_flush_console(uint32_t vtermno); extern void hvc_opal_init_early(void); diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c index cf02e602237a..6405b6f20193 100644 --- a/arch/powerpc/platforms/powernv/opal.c +++ b/arch/powerpc/platforms/powernv/opal.c @@ -344,9 +344,9 @@ int opal_get_chars(uint32_t vtermno, char *buf, int count) return 0; } -int opal_put_chars(uint32_t vtermno, const char *data, int total_len) +static int __opal_put_chars(uint32_t vtermno, const char *data, int total_len, bool atomic) { - unsigned long flags; + unsigned long flags = 0 /* shut up gcc */; int written; __be64 olen; s64 rc; @@ -354,11 +354,8 @@ int opal_put_chars(uint32_t vtermno, const char *data, int total_len) if (!opal.entry) return -ENODEV; - /* We want put_chars to be atomic to avoid mangling of hvsi - * packets. To do that, we first test for room and return - * -EAGAIN if there isn't enough. - */ - spin_lock_irqsave(&opal_write_lock, flags); + if (atomic) + spin_lock_irqsave(&opal_write_lock, flags); rc = opal_console_write_buffer_space(vtermno, &olen); if (rc || be64_to_cpu(olen) < total_len) { /* Closed -> drop characters */ @@ -391,14 +388,18 @@ int opal_put_chars(uint32_t vtermno, const char *data, int total_len) written = be64_to_cpu(olen); if (written < total_len) { - /* Should not happen */ - pr_warn("atomic console write returned partial len=%d written=%d\n", total_len, written); + if (atomic) { + /* Should not happen */ + pr_warn("atomic console write returned partial " + "len=%d written=%d\n", total_len, written); + } if (!written) written = -EAGAIN; } out: - spin_unlock_irqrestore(&opal_write_lock, flags); + if (atomic) + spin_unlock_irqrestore(&opal_write_lock, flags); /* In the -EAGAIN case, callers loop, so we have to flush the console * here in case they have interrupts off (and we don't want to wait @@ -412,6 +413,22 @@ out: return written; } +int opal_put_chars(uint32_t vtermno, const char *data, int total_len) +{ + return __opal_put_chars(vtermno, data, total_len, false); +} + +/* + * opal_put_chars_atomic will not perform partial-writes. Data will be + * atomically written to the terminal or not at all. This is not strictly + * true at the moment because console space can race with OPAL's console + * writes. + */ +int opal_put_chars_atomic(uint32_t vtermno, const char *data, int total_len) +{ + return __opal_put_chars(vtermno, data, total_len, true); +} + int opal_flush_console(uint32_t vtermno) { s64 rc; diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c index 958c61c8f35a..810fd42904c3 100644 --- a/drivers/tty/hvc/hvc_opal.c +++ b/drivers/tty/hvc/hvc_opal.c @@ -183,9 +183,15 @@ static int hvc_opal_probe(struct platform_device *dev) return -ENOMEM; pv->proto = proto; hvc_opal_privs[termno] = pv; - if (proto == HV_PROTOCOL_HVSI) - hvsilib_init(&pv->hvsi, opal_get_chars, opal_put_chars, + if (proto == HV_PROTOCOL_HVSI) { + /* + * We want put_chars to be atomic to avoid mangling of + * hvsi packets. + */ + hvsilib_init(&pv->hvsi, + opal_get_chars, opal_put_chars_atomic, termno, 0); + } /* Instanciate now to establish a mapping index==vtermno */ hvc_instantiate(termno, termno, ops); @@ -375,8 +381,9 @@ void __init hvc_opal_init_early(void) else if (of_device_is_compatible(stdout_node,"ibm,opal-console-hvsi")) { hvc_opal_boot_priv.proto = HV_PROTOCOL_HVSI; ops = &hvc_opal_hvsi_ops; - hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars, - opal_put_chars, index, 1); + hvsilib_init(&hvc_opal_boot_priv.hvsi, + opal_get_chars, opal_put_chars_atomic, + index, 1); /* HVSI, perform the handshake now */ hvsilib_establish(&hvc_opal_boot_priv.hvsi); pr_devel("hvc_opal: Found HVSI console\n"); @@ -408,7 +415,8 @@ void __init udbg_init_debug_opal_hvsi(void) hvc_opal_privs[index] = &hvc_opal_boot_priv; hvc_opal_boot_termno = index; udbg_init_opal_common(); - hvsilib_init(&hvc_opal_boot_priv.hvsi, opal_get_chars, opal_put_chars, + hvsilib_init(&hvc_opal_boot_priv.hvsi, + opal_get_chars, opal_put_chars_atomic, index, 1); hvsilib_establish(&hvc_opal_boot_priv.hvsi); } -- cgit v1.2.3-70-g09d2 From cca3d5290ede73b01144aa522910c88b1e02fcef Mon Sep 17 00:00:00 2001 From: Nicholas Piggin Date: Tue, 1 May 2018 00:55:52 +1000 Subject: tty: hvc: remove unexplained "just in case" spin delay This delay was in the very first OPAL console commit 6.5 years ago, and came from the vio hvc driver. The firmware console has hardened sufficiently to remove it. Reviewed-by: Benjamin Herrenschmidt Signed-off-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- drivers/tty/hvc/hvc_opal.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/hvc/hvc_opal.c b/drivers/tty/hvc/hvc_opal.c index 810fd42904c3..f631f8bee308 100644 --- a/drivers/tty/hvc/hvc_opal.c +++ b/drivers/tty/hvc/hvc_opal.c @@ -313,14 +313,8 @@ static int udbg_opal_getc(void) int ch; for (;;) { ch = udbg_opal_getc_poll(); - if (ch == -1) { - /* This shouldn't be needed...but... */ - volatile unsigned long delay; - for (delay=0; delay < 2000000; delay++) - ; - } else { + if (ch != -1) return ch; - } } } -- cgit v1.2.3-70-g09d2