[MIPS] vpe: handle halting TCs in an errata safe way.

Adds a JR.HB after halting a TC, to ensure that the TC has really halted.
only modifies the TCSTATUS register when the TC is safely halted.

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

1 files changed, 10 insertions, 4 deletions

diff --git a/arch/mips/kernel/vpe.c b/arch/mips/kernel/vpe.c
index 436a64ff3989..38bd33fa2a23 100644
--- a/arch/mips/kernel/vpe.c
+++ b/arch/mips/kernel/vpe.c
@@ -1003,6 +1003,7 @@ static void cleanup_tc(struct tc *tc)
         write_tc_c0_tcstatus(tmp);
 
         write_tc_c0_tchalt(TCHALT_H);
+        mips_ihb();
 
         /* bind it to anything other than VPE1 */
 //      write_tc_c0_tcbind(read_tc_c0_tcbind() & ~TCBIND_CURVPE); // | TCBIND_CURVPE
@@ -1235,9 +1236,12 @@ int vpe_free(vpe_handle vpe)
         settc(t->index);
         write_vpe_c0_vpeconf0(read_vpe_c0_vpeconf0() & ~VPECONF0_VPA);
 
-        /* mark the TC unallocated and halt'ed */
-        write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);
+        /* halt the TC */
         write_tc_c0_tchalt(TCHALT_H);
+        mips_ihb();
+
+        /* mark the TC unallocated */
+        write_tc_c0_tcstatus(read_tc_c0_tcstatus() & ~TCSTATUS_A);
 
         v->state = VPE_STATE_UNUSED;
 
@@ -1533,14 +1537,16 @@ static int __init vpe_module_init(void)
                                 t->pvpe = get_vpe(0);   /* set the parent vpe */
                         }
 
+                        /* halt the TC */
+                        write_tc_c0_tchalt(TCHALT_H);
+                        mips_ihb();
+
                         tmp = read_tc_c0_tcstatus();
 
                         /* mark not activated and not dynamically allocatable */
                         tmp &= ~(TCSTATUS_A | TCSTATUS_DA);
                         tmp |= TCSTATUS_IXMT;   /* interrupt exempt */
                         write_tc_c0_tcstatus(tmp);
-
-                        write_tc_c0_tchalt(TCHALT_H);
                 }
         }