summaryrefslogtreecommitdiff
path: root/drivers/tty/hvc
diff options
context:
space:
mode:
authorNicholas Piggin <npiggin@gmail.com>2018-05-01 00:55:51 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2018-07-24 22:09:57 +1000
commit17cc1dd4924391b54fb179d0868b89dc96f2ee80 (patch)
tree18aada7559529c711897037d94b316a6d26cfa63 /drivers/tty/hvc
parentac4ac788fdadc6b703ff3322de07dee442e08e1c (diff)
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 <benh@kernel.crashing.org> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'drivers/tty/hvc')
-rw-r--r--drivers/tty/hvc/hvc_opal.c18
1 files changed, 13 insertions, 5 deletions
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);
}