[POWERPC] Add spinlock to request_phb_iospace()

request_phb_iospace() can be called from different CPUs at init
time (at least with my next patch) and thus needs a spinlock.
As for the next patch, this is a temporary workaround for 2.6.22
issues until my rewrite of IO mappings is ready (for 2.6.23)

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 1d443407423c..ad6e135bf212 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -322,6 +322,8 @@ EXPORT_SYMBOL(__ioremap);
 EXPORT_SYMBOL(iounmap);
 EXPORT_SYMBOL(__iounmap);
 
+static DEFINE_SPINLOCK(phb_io_lock);
+
 void __iomem * reserve_phb_iospace(unsigned long size)
 {
         void __iomem *virt_addr;
@@ -329,8 +331,10 @@ void __iomem * reserve_phb_iospace(unsigned long size)
         if (phbs_io_bot >= IMALLOC_BASE) 
                 panic("reserve_phb_iospace(): phb io space overflow\n");
                         
+        spin_lock(&phb_io_lock);
         virt_addr = (void __iomem *) phbs_io_bot;
         phbs_io_bot += size;
+        spin_unlock(&phb_io_lock);
 
         return virt_addr;
 }