Subject: [PATCH 3/3] [v2] hvc_dcc: disable user-space access to DCC

From: [email-masked] (Will Deacon)
Date: Thu, 20 Aug 2015 11:46:45 +0100

On Thu, Aug 20, 2015 at 12:02:50AM +0100, Timur Tabi wrote:
> If the DCC driver loads, then disable user-space access to the DCC so that
> we don't have two entities trying to access the DCC at the same time.

In the interests of making some headway with this, just drop this patch
and I'll queue the diff below via the arm64 tree.

Will

--->8

diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 39139a3aa16d..4c922ecce600 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -156,7 +156,7 @@ ENTRY(__cpu_setup)
 
 	mov	x0, #3 << 20
 	msr	cpacr_el1, x0			// Enable FP/ASIMD
-	msr	mdscr_el1, xzr			// Reset mdscr_el1
+	msr	mdscr_el1, #1 << 12		// Reset mdscr_el1
 	/*
 	 * Memory region attributes for LPAE:
 	 *