commit 4b236b621bf090509c4a0be372edfd31d13b289a
author Benjamin Herrenschmidt <benh@kernel.crashing.org> Mon Jun 27 08:55:19 2016 +0200
committer David Gibson <david@gibson.dropbear.id.au> Fri Jul 01 09:57:01 2016 +1000
tree 6a68f8e5a2f3dafbc1762427efc37abd3855219a
parent b378bb0948277d71c78bc6d0c1ef80a253aafc80

ppc: Initial HDEC support

The current behaviour isn't completely right, as for the DEC, we
don't properly re-arm when wrapping around, but I will fix this
in a separate patch.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[clg: fixed checkpatch.pl errors ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

target-ppc/excp_helper.c

diff --git a/target-ppc/excp_helper.c b/target-ppc/excp_helper.c
index 26adda4..d6e1678 100644
--- a/target-ppc/excp_helper.c
+++ b/target-ppc/excp_helper.c
@@ -753,7 +753,6 @@
 static void ppc_hw_interrupt(CPUPPCState *env)
 {
     PowerPCCPU *cpu = ppc_env_get_cpu(env);
-    int hdice;
 #if 0
     CPUState *cs = CPU(cpu);
 
@@ -781,15 +780,13 @@
         return;
     }
 #endif
-    if (0) {
-        /* XXX: find a suitable condition to enable the hypervisor mode */
-        hdice = env->spr[SPR_LPCR] & 1;
-    } else {
-        hdice = 0;
-    }
-    if ((msr_ee != 0 || msr_hv == 0 || msr_pr != 0) && hdice != 0) {
-        /* Hypervisor decrementer exception */
-        if (env->pending_interrupts & (1 << PPC_INTERRUPT_HDECR)) {
+    /* Hypervisor decrementer exception */
+    if (env->pending_interrupts & (1 << PPC_INTERRUPT_HDECR)) {
+        /* LPCR will be clear when not supported so this will work */
+        bool hdice = !!(env->spr[SPR_LPCR] & LPCR_HDICE);
+        if ((msr_ee != 0 || msr_hv == 0) && hdice) {
+            /* HDEC clears on delivery */
+            env->pending_interrupts &= ~(1 << PPC_INTERRUPT_HDECR);
             powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_HDECR);
             return;
         }
@@ -941,6 +938,11 @@
     cs->halted = 1;
     env->in_pm_state = true;
 
+    /* The architecture specifies that HDEC interrupts are
+     * discarded in PM states
+     */
+    env->pending_interrupts &= ~(1 << PPC_INTERRUPT_HDECR);
+
     /* Technically, nap doesn't set EE, but if we don't set it
      * then ppc_hw_interrupt() won't deliver. We could add some
      * other tests there based on LPCR but it's simpler to just