From: Elizabeth Oldham <beth@mips.com>
Date: Thu, 17 Aug 2006 11:39:21 +0000 (+0100)
Subject: [MIPS] MT: Fix setting of XTC.
X-Git-Tag: firefly_0821_release~33422
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a94d702049569401c65b579d0751ce282f962b41;p=firefly-linux-kernel-4.4.55.git

[MIPS] MT: Fix setting of XTC.

XTC can only be set if VPA is clear, which it may not be. There is
also the possibility of a back to back c0 register access hazard to
take care of.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---

diff --git a/arch/mips/kernel/vpe.c b/arch/mips/kernel/vpe.c
index 9ee0ec2cd067..51ddd2166898 100644
--- a/arch/mips/kernel/vpe.c
+++ b/arch/mips/kernel/vpe.c
@@ -768,10 +768,16 @@ int vpe_run(struct vpe * v)
 	 */
  	write_tc_c0_tcbind((read_tc_c0_tcbind() & ~TCBIND_CURVPE) | v->minor);
 
+	write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~(VPECONF0_VPA));
+
+	back_to_back_c0_hazard();
+
         /* Set up the XTC bit in vpeconf0 to point at our tc */
         write_vpe_c0_vpeconf0( (read_vpe_c0_vpeconf0() & ~(VPECONF0_XTC))
                                | (t->index << VPECONF0_XTC_SHIFT));
 
+	back_to_back_c0_hazard();
+
         /* enable this VPE */
         write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() | VPECONF0_VPA);