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authorScott Wood <oss@buserror.net>2016-03-03 05:51:04 +0100
committerScott Wood <oss@buserror.net>2016-03-04 06:43:05 +0100
commit37c5e942bb2eedd98c1cd1fa1f94d79f6b830c38 (patch)
tree2d846e3812b414f352d91779c311e4b08f1cd069 /arch/powerpc/mm/hugetlbpage-book3e.c
parentpowerpc/hw_breakpoint: Fix oops when destroying hw_breakpoint event (diff)
downloadlinux-37c5e942bb2eedd98c1cd1fa1f94d79f6b830c38.tar.xz
linux-37c5e942bb2eedd98c1cd1fa1f94d79f6b830c38.zip
powerpc/fsl-book3e: Avoid lbarx on e5500
lbarx/stbcx. are implemented on e6500, but not on e5500. Likewise, SMT is on e6500, but not on e5500. So, avoid executing an unimplemented instruction by only locking when needed (i.e. in the presence of SMT). Signed-off-by: Scott Wood <oss@buserror.net>
Diffstat (limited to 'arch/powerpc/mm/hugetlbpage-book3e.c')
-rw-r--r--arch/powerpc/mm/hugetlbpage-book3e.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hugetlbpage-book3e.c b/arch/powerpc/mm/hugetlbpage-book3e.c
index 7e6d0880813f..83a8be791e06 100644
--- a/arch/powerpc/mm/hugetlbpage-book3e.c
+++ b/arch/powerpc/mm/hugetlbpage-book3e.c
@@ -8,6 +8,8 @@
#include <linux/mm.h>
#include <linux/hugetlb.h>
+#include <asm/mmu.h>
+
#ifdef CONFIG_PPC_FSL_BOOK3E
#ifdef CONFIG_PPC64
static inline int tlb1_next(void)
@@ -60,6 +62,14 @@ static inline void book3e_tlb_lock(void)
unsigned long tmp;
int token = smp_processor_id() + 1;
+ /*
+ * Besides being unnecessary in the absence of SMT, this
+ * check prevents trying to do lbarx/stbcx. on e5500 which
+ * doesn't implement either feature.
+ */
+ if (!cpu_has_feature(CPU_FTR_SMT))
+ return;
+
asm volatile("1: lbarx %0, 0, %1;"
"cmpwi %0, 0;"
"bne 2f;"
@@ -80,6 +90,9 @@ static inline void book3e_tlb_unlock(void)
{
struct paca_struct *paca = get_paca();
+ if (!cpu_has_feature(CPU_FTR_SMT))
+ return;
+
isync();
paca->tcd_ptr->lock = 0;
}