arm64: head.S: initialise mdcr_el2 in el2_setup

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / kernel / head.S

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index a055be6125cf592d06e957df0b1125d409c9a5cf..90d09eddd5b27368e358efd44ab552db8330d39c 100644 (file)
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S
@@ -523,6 +523,11 @@ CPU_LE(    movk    x0, #0x30d0, lsl #16    )       // Clear EE and E0E on LE systems
        msr     hstr_el2, xzr                   // Disable CP15 traps to EL2
 #endif
 
+       /* EL2 debug */
+       mrs     x0, pmcr_el0                    // Disable debug access traps
+       ubfx    x0, x0, #11, #5                 // to EL2 and allow access to
+       msr     mdcr_el2, x0                    // all PMU counters from EL1
+
        /* Stage-2 translation */
        msr     vttbr_el2, xzr