X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=arch%2Farm64%2Fmm%2Fproc-macros.S;h=d69dffffaa8993bc7260c1df035b92c3b3867b48;hb=f4a65209ddfce90381787859b97034f405820d63;hp=4c4d93c4bf65b154fd0df25c4b8165593ff044be;hpb=8ea3a7c0df05b2cb33e2d63aa1c964308724b1c4;p=firefly-linux-kernel-4.4.55.git

diff --git a/arch/arm64/mm/proc-macros.S b/arch/arm64/mm/proc-macros.S
index 4c4d93c4bf65..d69dffffaa89 100644
--- a/arch/arm64/mm/proc-macros.S
+++ b/arch/arm64/mm/proc-macros.S
@@ -62,3 +62,15 @@
 	bfi	\valreg, \tmpreg, #TCR_T0SZ_OFFSET, #TCR_TxSZ_WIDTH
 #endif
 	.endm
+
+/*
+ * reset_pmuserenr_el0 - reset PMUSERENR_EL0 if PMUv3 present
+ */
+	.macro	reset_pmuserenr_el0, tmpreg
+	mrs	\tmpreg, id_aa64dfr0_el1	// Check ID_AA64DFR0_EL1 PMUVer
+	sbfx	\tmpreg, \tmpreg, #8, #4
+	cmp	\tmpreg, #1			// Skip if no PMU present
+	b.lt	9000f
+	msr	pmuserenr_el0, xzr		// Disable PMU access from EL0
+9000:
+	.endm