ptimer: Add TRIGGER_ONLY_ON_DECREMENT policy option

The CMSDK timer behaviour is that an interrupt is triggered when the
counter counts down from 1 to 0; however one is not triggered if the
counter is manually set to 0 by a guest write to the counter register.
Currently ptimer can't handle this; add a policy option to allow
a ptimer user to request this behaviour.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Message-id: 20180703171044.9503-2-peter.maydell@linaro.org

1 files changed, 19 insertions, 6 deletions

diff --git a/tests/ptimer-test.c b/tests/ptimer-test.c
index 4148889..b30aad0 100644
--- a/tests/ptimer-test.c
+++ b/tests/ptimer-test.c
@@ -208,6 +208,7 @@ static void check_periodic(gconstpointer arg)
     bool no_immediate_trigger = (*policy & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER);
     bool no_immediate_reload = (*policy & PTIMER_POLICY_NO_IMMEDIATE_RELOAD);
     bool no_round_down = (*policy & PTIMER_POLICY_NO_COUNTER_ROUND_DOWN);
+    bool trig_only_on_dec = (*policy & PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT);
 
     triggered = false;
 
@@ -311,7 +312,7 @@ static void check_periodic(gconstpointer arg)
     g_assert_cmpuint(ptimer_get_count(ptimer), ==,
                      no_immediate_reload ? 0 : 10);
 
-    if (no_immediate_trigger) {
+    if (no_immediate_trigger || trig_only_on_dec) {
         g_assert_false(triggered);
     } else {
         g_assert_true(triggered);
@@ -506,6 +507,7 @@ static void check_run_with_delta_0(gconstpointer arg)
     bool no_immediate_trigger = (*policy & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER);
     bool no_immediate_reload = (*policy & PTIMER_POLICY_NO_IMMEDIATE_RELOAD);
     bool no_round_down = (*policy & PTIMER_POLICY_NO_COUNTER_ROUND_DOWN);
+    bool trig_only_on_dec = (*policy & PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT);
 
     triggered = false;
 
@@ -515,7 +517,7 @@ static void check_run_with_delta_0(gconstpointer arg)
     g_assert_cmpuint(ptimer_get_count(ptimer), ==,
                      no_immediate_reload ? 0 : 99);
 
-    if (no_immediate_trigger) {
+    if (no_immediate_trigger || trig_only_on_dec) {
         g_assert_false(triggered);
     } else {
         g_assert_true(triggered);
@@ -563,7 +565,7 @@ static void check_run_with_delta_0(gconstpointer arg)
     g_assert_cmpuint(ptimer_get_count(ptimer), ==,
                      no_immediate_reload ? 0 : 99);
 
-    if (no_immediate_trigger) {
+    if (no_immediate_trigger || trig_only_on_dec) {
         g_assert_false(triggered);
     } else {
         g_assert_true(triggered);
@@ -609,6 +611,7 @@ static void check_periodic_with_load_0(gconstpointer arg)
     ptimer_state *ptimer = ptimer_init(bh, *policy);
     bool continuous_trigger = (*policy & PTIMER_POLICY_CONTINUOUS_TRIGGER);
     bool no_immediate_trigger = (*policy & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER);
+    bool trig_only_on_dec = (*policy & PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT);
 
     triggered = false;
 
@@ -617,7 +620,7 @@ static void check_periodic_with_load_0(gconstpointer arg)
 
     g_assert_cmpuint(ptimer_get_count(ptimer), ==, 0);
 
-    if (no_immediate_trigger) {
+    if (no_immediate_trigger || trig_only_on_dec) {
         g_assert_false(triggered);
     } else {
         g_assert_true(triggered);
@@ -667,6 +670,7 @@ static void check_oneshot_with_load_0(gconstpointer arg)
     QEMUBH *bh = qemu_bh_new(ptimer_trigger, NULL);
     ptimer_state *ptimer = ptimer_init(bh, *policy);
     bool no_immediate_trigger = (*policy & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER);
+    bool trig_only_on_dec = (*policy & PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT);
 
     triggered = false;
 
@@ -675,7 +679,7 @@ static void check_oneshot_with_load_0(gconstpointer arg)
 
     g_assert_cmpuint(ptimer_get_count(ptimer), ==, 0);
 
-    if (no_immediate_trigger) {
+    if (no_immediate_trigger || trig_only_on_dec) {
         g_assert_false(triggered);
     } else {
         g_assert_true(triggered);
@@ -725,6 +729,10 @@ static void add_ptimer_tests(uint8_t policy)
         g_strlcat(policy_name, "no_counter_rounddown,", 256);
     }
 
+    if (policy & PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT) {
+        g_strlcat(policy_name, "trigger_only_on_decrement,", 256);
+    }
+
     g_test_add_data_func_full(
         tmp = g_strdup_printf("/ptimer/set_count policy=%s", policy_name),
         g_memdup(&policy, 1), check_set_count, g_free);
@@ -790,10 +798,15 @@ static void add_ptimer_tests(uint8_t policy)
 
 static void add_all_ptimer_policies_comb_tests(void)
 {
-    int last_policy = PTIMER_POLICY_NO_COUNTER_ROUND_DOWN;
+    int last_policy = PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT;
     int policy = PTIMER_POLICY_DEFAULT;
 
     for (; policy < (last_policy << 1); policy++) {
+        if ((policy & PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT) &&
+            (policy & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER)) {
+            /* Incompatible policy flag settings -- don't try to test them */
+            continue;
+        }
         add_ptimer_tests(policy);
     }
 }