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authorDavid S. Miller <davem@davemloft.net>2010-03-03 09:06:03 -0800
committerDavid S. Miller <davem@davemloft.net>2010-03-03 09:06:03 -0800
commit8a4fd1e4922413cfdfa6c51a59efb720d904a5eb (patch)
tree3e46821fac9d3de604466b55345c2b267d157355 /arch/sparc/prom
parentsparc64: Kill off old sys_perfctr system call and state. (diff)
downloadlinux-dev-8a4fd1e4922413cfdfa6c51a59efb720d904a5eb.tar.xz
linux-dev-8a4fd1e4922413cfdfa6c51a59efb720d904a5eb.zip
sparc64: Make prom entry spinlock NMI safe.
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>
Diffstat (limited to '')
-rw-r--r--arch/sparc/prom/p1275.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/arch/sparc/prom/p1275.c b/arch/sparc/prom/p1275.c
index 4b7c937bba61..2d8b70d397f1 100644
--- a/arch/sparc/prom/p1275.c
+++ b/arch/sparc/prom/p1275.c
@@ -32,10 +32,9 @@ 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);
+DEFINE_RAW_SPINLOCK(prom_entry_lock);
long p1275_cmd(const char *service, long fmt, ...)
{
@@ -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);
+ raw_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);
+ raw_spin_unlock(&prom_entry_lock);
+ raw_local_irq_restore(flags);
return x;
}