From 086ede32afc9c70de3d75c4fb91c63db790cbd5c Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Mon, 9 Jul 2018 14:51:34 +0100 Subject: 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 Reviewed-by: Richard Henderson Tested-by: Guenter Roeck Message-id: 20180703171044.9503-2-peter.maydell@linaro.org --- hw/core/ptimer.c | 22 +++++++++++++++++++++- include/hw/ptimer.h | 9 +++++++++ tests/ptimer-test.c | 25 +++++++++++++++++++------ 3 files changed, 49 insertions(+), 7 deletions(-) diff --git a/hw/core/ptimer.c b/hw/core/ptimer.c index 7221c68a98..170fd34d8b 100644 --- a/hw/core/ptimer.c +++ b/hw/core/ptimer.c @@ -45,8 +45,20 @@ static void ptimer_reload(ptimer_state *s, int delta_adjust) uint32_t period_frac = s->period_frac; uint64_t period = s->period; uint64_t delta = s->delta; + bool suppress_trigger = false; - if (delta == 0 && !(s->policy_mask & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER)) { + /* + * Note that if delta_adjust is 0 then we must be here because of + * a count register write or timer start, not because of timer expiry. + * In that case the policy might require us to suppress the timer trigger + * that we would otherwise generate for a zero delta. + */ + if (delta_adjust == 0 && + (s->policy_mask & PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT)) { + suppress_trigger = true; + } + if (delta == 0 && !(s->policy_mask & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER) + && !suppress_trigger) { ptimer_trigger(s); } @@ -353,6 +365,14 @@ ptimer_state *ptimer_init(QEMUBH *bh, uint8_t policy_mask) s->bh = bh; s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, ptimer_tick, s); s->policy_mask = policy_mask; + + /* + * These two policies are incompatible -- trigger-on-decrement implies + * a timer trigger when the count becomes 0, but no-immediate-trigger + * implies a trigger when the count stops being 0. + */ + assert(!((policy_mask & PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT) && + (policy_mask & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER))); return s; } diff --git a/include/hw/ptimer.h b/include/hw/ptimer.h index fc4ef5cc1d..0731d9aef1 100644 --- a/include/hw/ptimer.h +++ b/include/hw/ptimer.h @@ -69,6 +69,15 @@ * not the one less. */ #define PTIMER_POLICY_NO_COUNTER_ROUND_DOWN (1 << 4) +/* + * Starting to run with a zero counter, or setting the counter to "0" via + * ptimer_set_count() or ptimer_set_limit() will not trigger the timer + * (though it will cause a reload). Only a counter decrement to "0" + * will cause a trigger. Not compatible with NO_IMMEDIATE_TRIGGER; + * ptimer_init() will assert() that you don't set both. + */ +#define PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT (1 << 5) + /* ptimer.c */ typedef struct ptimer_state ptimer_state; typedef void (*ptimer_cb)(void *opaque); diff --git a/tests/ptimer-test.c b/tests/ptimer-test.c index 41488896f7..b30aad0737 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); } } -- cgit v1.2.3