diff options
| author | David S. Miller <davem@davemloft.net> | 2010-03-03 09:06:03 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-04-01 15:58:16 -0700 |
| commit | a6c4c1c5057d956af87679861f5eeb80c72e3a5e (patch) | |
| tree | 6f98c62ed780865a8e2955240bc03399378f25fd /arch/sparc | |
| parent | 8c2b12e12010928b6c5dd06447eccb99b0629515 (diff) | |
sparc64: Make prom entry spinlock NMI safe.
[ Upstream commit 8a4fd1e4922413cfdfa6c51a59efb720d904a5eb ]
If we do something like try to print to the OF console from an NMI
while we're already in OpenFirmware, we'll deadlock on the spinlock.
Use a raw spinlock and disable NMIs when we take it.
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'arch/sparc')
| -rw-r--r-- | arch/sparc/prom/p1275.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/arch/sparc/prom/p1275.c b/arch/sparc/prom/p1275.c index 4b7c937bba61..815cab6be5a3 100644 --- a/arch/sparc/prom/p1275.c +++ b/arch/sparc/prom/p1275.c @@ -32,8 +32,7 @@ extern void prom_cif_interface(void); extern void prom_cif_callback(void); /* - * This provides SMP safety on the p1275buf. prom_callback() drops this lock - * to allow recursuve acquisition. + * This provides SMP safety on the p1275buf. */ DEFINE_SPINLOCK(prom_entry_lock); @@ -47,7 +46,9 @@ long p1275_cmd(const char *service, long fmt, ...) p = p1275buf.prom_buffer; - spin_lock_irqsave(&prom_entry_lock, flags); + raw_local_save_flags(flags); + raw_local_irq_restore(PIL_NMI); + spin_lock(&prom_entry_lock); p1275buf.prom_args[0] = (unsigned long)p; /* service */ strcpy (p, service); @@ -139,7 +140,8 @@ long p1275_cmd(const char *service, long fmt, ...) va_end(list); x = p1275buf.prom_args [nargs + 3]; - spin_unlock_irqrestore(&prom_entry_lock, flags); + spin_unlock(&prom_entry_lock); + raw_local_irq_restore(flags); return x; } |