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-rw-r--r--hw/ppc/ppc.c92
-rw-r--r--include/hw/ppc/ppc.h3
-rw-r--r--target-ppc/cpu.h1
-rw-r--r--target-ppc/excp_helper.c5
4 files changed, 71 insertions, 30 deletions
diff --git a/hw/ppc/ppc.c b/hw/ppc/ppc.c
index 9c2a13280b..71df471746 100644
--- a/hw/ppc/ppc.c
+++ b/hw/ppc/ppc.c
@@ -620,6 +620,13 @@ static void cpu_ppc_tb_start (CPUPPCState *env)
}
}
+bool ppc_decr_clear_on_delivery(CPUPPCState *env)
+{
+ ppc_tb_t *tb_env = env->tb_env;
+ int flags = PPC_DECR_UNDERFLOW_TRIGGERED | PPC_DECR_UNDERFLOW_LEVEL;
+ return ((tb_env->flags & flags) == PPC_DECR_UNDERFLOW_TRIGGERED);
+}
+
static inline uint32_t _cpu_ppc_load_decr(CPUPPCState *env, uint64_t next)
{
ppc_tb_t *tb_env = env->tb_env;
@@ -677,6 +684,11 @@ static inline void cpu_ppc_decr_excp(PowerPCCPU *cpu)
ppc_set_irq(cpu, PPC_INTERRUPT_DECR, 1);
}
+static inline void cpu_ppc_decr_lower(PowerPCCPU *cpu)
+{
+ ppc_set_irq(cpu, PPC_INTERRUPT_DECR, 0);
+}
+
static inline void cpu_ppc_hdecr_excp(PowerPCCPU *cpu)
{
/* Raise it */
@@ -684,11 +696,16 @@ static inline void cpu_ppc_hdecr_excp(PowerPCCPU *cpu)
ppc_set_irq(cpu, PPC_INTERRUPT_HDECR, 1);
}
+static inline void cpu_ppc_hdecr_lower(PowerPCCPU *cpu)
+{
+ ppc_set_irq(cpu, PPC_INTERRUPT_HDECR, 0);
+}
+
static void __cpu_ppc_store_decr(PowerPCCPU *cpu, uint64_t *nextp,
QEMUTimer *timer,
- void (*raise_excp)(PowerPCCPU *),
- uint32_t decr, uint32_t value,
- int is_excp)
+ void (*raise_excp)(void *),
+ void (*lower_excp)(PowerPCCPU *),
+ uint32_t decr, uint32_t value)
{
CPUPPCState *env = &cpu->env;
ppc_tb_t *tb_env = env->tb_env;
@@ -702,59 +719,74 @@ static void __cpu_ppc_store_decr(PowerPCCPU *cpu, uint64_t *nextp,
return;
}
- now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
- next = now + muldiv64(value, get_ticks_per_sec(), tb_env->decr_freq);
- if (is_excp) {
- next += *nextp - now;
+ /*
+ * Going from 2 -> 1, 1 -> 0 or 0 -> -1 is the event to generate a DEC
+ * interrupt.
+ *
+ * If we get a really small DEC value, we can assume that by the time we
+ * handled it we should inject an interrupt already.
+ *
+ * On MSB level based DEC implementations the MSB always means the interrupt
+ * is pending, so raise it on those.
+ *
+ * On MSB edge based DEC implementations the MSB going from 0 -> 1 triggers
+ * an edge interrupt, so raise it here too.
+ */
+ if ((value < 3) ||
+ ((tb_env->flags & PPC_DECR_UNDERFLOW_LEVEL) && (value & 0x80000000)) ||
+ ((tb_env->flags & PPC_DECR_UNDERFLOW_TRIGGERED) && (value & 0x80000000)
+ && !(decr & 0x80000000))) {
+ (*raise_excp)(cpu);
+ return;
}
- if (next == now) {
- next++;
+
+ /* On MSB level based systems a 0 for the MSB stops interrupt delivery */
+ if (!(value & 0x80000000) && (tb_env->flags & PPC_DECR_UNDERFLOW_LEVEL)) {
+ (*lower_excp)(cpu);
}
+
+ /* Calculate the next timer event */
+ now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+ next = now + muldiv64(value, get_ticks_per_sec(), tb_env->decr_freq);
*nextp = next;
+
/* Adjust timer */
timer_mod(timer, next);
-
- /* If we set a negative value and the decrementer was positive, raise an
- * exception.
- */
- if ((tb_env->flags & PPC_DECR_UNDERFLOW_TRIGGERED)
- && (value & 0x80000000)
- && !(decr & 0x80000000)) {
- (*raise_excp)(cpu);
- }
}
static inline void _cpu_ppc_store_decr(PowerPCCPU *cpu, uint32_t decr,
- uint32_t value, int is_excp)
+ uint32_t value)
{
ppc_tb_t *tb_env = cpu->env.tb_env;
__cpu_ppc_store_decr(cpu, &tb_env->decr_next, tb_env->decr_timer,
- &cpu_ppc_decr_excp, decr, value, is_excp);
+ tb_env->decr_timer->cb, &cpu_ppc_decr_lower, decr,
+ value);
}
void cpu_ppc_store_decr (CPUPPCState *env, uint32_t value)
{
PowerPCCPU *cpu = ppc_env_get_cpu(env);
- _cpu_ppc_store_decr(cpu, cpu_ppc_load_decr(env), value, 0);
+ _cpu_ppc_store_decr(cpu, cpu_ppc_load_decr(env), value);
}
static void cpu_ppc_decr_cb(void *opaque)
{
PowerPCCPU *cpu = opaque;
- _cpu_ppc_store_decr(cpu, 0x00000000, 0xFFFFFFFF, 1);
+ cpu_ppc_decr_excp(cpu);
}
static inline void _cpu_ppc_store_hdecr(PowerPCCPU *cpu, uint32_t hdecr,
- uint32_t value, int is_excp)
+ uint32_t value)
{
ppc_tb_t *tb_env = cpu->env.tb_env;
if (tb_env->hdecr_timer != NULL) {
__cpu_ppc_store_decr(cpu, &tb_env->hdecr_next, tb_env->hdecr_timer,
- &cpu_ppc_hdecr_excp, hdecr, value, is_excp);
+ tb_env->hdecr_timer->cb, &cpu_ppc_hdecr_lower,
+ hdecr, value);
}
}
@@ -762,14 +794,14 @@ void cpu_ppc_store_hdecr (CPUPPCState *env, uint32_t value)
{
PowerPCCPU *cpu = ppc_env_get_cpu(env);
- _cpu_ppc_store_hdecr(cpu, cpu_ppc_load_hdecr(env), value, 0);
+ _cpu_ppc_store_hdecr(cpu, cpu_ppc_load_hdecr(env), value);
}
static void cpu_ppc_hdecr_cb(void *opaque)
{
PowerPCCPU *cpu = opaque;
- _cpu_ppc_store_hdecr(cpu, 0x00000000, 0xFFFFFFFF, 1);
+ cpu_ppc_hdecr_excp(cpu);
}
static void cpu_ppc_store_purr(PowerPCCPU *cpu, uint64_t value)
@@ -792,8 +824,8 @@ static void cpu_ppc_set_tb_clk (void *opaque, uint32_t freq)
* if a decrementer exception is pending when it enables msr_ee at startup,
* it's not ready to handle it...
*/
- _cpu_ppc_store_decr(cpu, 0xFFFFFFFF, 0xFFFFFFFF, 0);
- _cpu_ppc_store_hdecr(cpu, 0xFFFFFFFF, 0xFFFFFFFF, 0);
+ _cpu_ppc_store_decr(cpu, 0xFFFFFFFF, 0xFFFFFFFF);
+ _cpu_ppc_store_hdecr(cpu, 0xFFFFFFFF, 0xFFFFFFFF);
cpu_ppc_store_purr(cpu, 0x0000000000000000ULL);
}
@@ -806,6 +838,10 @@ clk_setup_cb cpu_ppc_tb_init (CPUPPCState *env, uint32_t freq)
tb_env = g_malloc0(sizeof(ppc_tb_t));
env->tb_env = tb_env;
tb_env->flags = PPC_DECR_UNDERFLOW_TRIGGERED;
+ if (env->insns_flags & PPC_SEGMENT_64B) {
+ /* All Book3S 64bit CPUs implement level based DEC logic */
+ tb_env->flags |= PPC_DECR_UNDERFLOW_LEVEL;
+ }
/* Create new timer */
tb_env->decr_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &cpu_ppc_decr_cb, cpu);
if (0) {
diff --git a/include/hw/ppc/ppc.h b/include/hw/ppc/ppc.h
index 835418aeb0..d71bd07497 100644
--- a/include/hw/ppc/ppc.h
+++ b/include/hw/ppc/ppc.h
@@ -44,6 +44,9 @@ struct ppc_tb_t {
#define PPC_DECR_ZERO_TRIGGERED (1 << 3) /* Decr interrupt triggered when
* the decrementer reaches zero.
*/
+#define PPC_DECR_UNDERFLOW_LEVEL (1 << 4) /* Decr interrupt active when
+ * the most significant bit is 1.
+ */
uint64_t cpu_ppc_get_tb(ppc_tb_t *tb_env, uint64_t vmclk, int64_t tb_offset);
clk_setup_cb cpu_ppc_tb_init (CPUPPCState *env, uint32_t freq);
diff --git a/target-ppc/cpu.h b/target-ppc/cpu.h
index 2719c08323..d4983405a2 100644
--- a/target-ppc/cpu.h
+++ b/target-ppc/cpu.h
@@ -1133,6 +1133,7 @@ uint64_t cpu_ppc_load_atbl (CPUPPCState *env);
uint32_t cpu_ppc_load_atbu (CPUPPCState *env);
void cpu_ppc_store_atbl (CPUPPCState *env, uint32_t value);
void cpu_ppc_store_atbu (CPUPPCState *env, uint32_t value);
+bool ppc_decr_clear_on_delivery(CPUPPCState *env);
uint32_t cpu_ppc_load_decr (CPUPPCState *env);
void cpu_ppc_store_decr (CPUPPCState *env, uint32_t value);
uint32_t cpu_ppc_load_hdecr (CPUPPCState *env);
diff --git a/target-ppc/excp_helper.c b/target-ppc/excp_helper.c
index 19bc6b66ba..4fa297d7dd 100644
--- a/target-ppc/excp_helper.c
+++ b/target-ppc/excp_helper.c
@@ -723,7 +723,6 @@ void ppc_hw_interrupt(CPUPPCState *env)
if ((msr_ee != 0 || msr_hv == 0 || msr_pr != 0) && hdice != 0) {
/* Hypervisor decrementer exception */
if (env->pending_interrupts & (1 << PPC_INTERRUPT_HDECR)) {
- env->pending_interrupts &= ~(1 << PPC_INTERRUPT_HDECR);
powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_HDECR);
return;
}
@@ -767,7 +766,9 @@ void ppc_hw_interrupt(CPUPPCState *env)
}
/* Decrementer exception */
if (env->pending_interrupts & (1 << PPC_INTERRUPT_DECR)) {
- env->pending_interrupts &= ~(1 << PPC_INTERRUPT_DECR);
+ if (ppc_decr_clear_on_delivery(env)) {
+ env->pending_interrupts &= ~(1 << PPC_INTERRUPT_DECR);
+ }
powerpc_excp(cpu, env->excp_model, POWERPC_EXCP_DECR);
return;
}