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-rw-r--r--arch/ppc64/kernel/pmc.c21
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/ppc64/kernel/pmc.c b/arch/ppc64/kernel/pmc.c
index 67be773f9c0..cdfec7438d0 100644
--- a/arch/ppc64/kernel/pmc.c
+++ b/arch/ppc64/kernel/pmc.c
@@ -65,3 +65,24 @@ void release_pmc_hardware(void)
spin_unlock(&pmc_owner_lock);
}
EXPORT_SYMBOL_GPL(release_pmc_hardware);
+
+void power4_enable_pmcs(void)
+{
+ unsigned long hid0;
+
+ hid0 = mfspr(HID0);
+ hid0 |= 1UL << (63 - 20);
+
+ /* POWER4 requires the following sequence */
+ asm volatile(
+ "sync\n"
+ "mtspr %1, %0\n"
+ "mfspr %0, %1\n"
+ "mfspr %0, %1\n"
+ "mfspr %0, %1\n"
+ "mfspr %0, %1\n"
+ "mfspr %0, %1\n"
+ "mfspr %0, %1\n"
+ "isync" : "=&r" (hid0) : "i" (HID0), "0" (hid0):
+ "memory");
+}