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| author | Nicholas Piggin <npiggin@gmail.com> | 2018-05-01 00:55:51 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-07-24 22:09:57 +1000 |
| commit | 17cc1dd4924391b54fb179d0868b89dc96f2ee80 (patch) | |
| tree | 18aada7559529c711897037d94b316a6d26cfa63 /drivers/tty/hvc/hvc_opal.c | |
| parent | ac4ac788fdadc6b703ff3322de07dee442e08e1c (diff) | |
| download | linux-17cc1dd4924391b54fb179d0868b89dc96f2ee80.tar.gz linux-17cc1dd4924391b54fb179d0868b89dc96f2ee80.tar.bz2 linux-17cc1dd4924391b54fb179d0868b89dc96f2ee80.zip | |
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/hvc_opal.c')
| -rw-r--r-- | drivers/tty/hvc/hvc_opal.c | 18 |
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); } |