@@ -114,6 +114,7 @@ FIELD(CR_STATUS, CRS, 10, 6)
FIELD(CR_STATUS, PRS, 16, 6)
FIELD(CR_STATUS, NMI, 22, 1)
FIELD(CR_STATUS, RSIE, 23, 1)
+FIELD(CR_STATUS, SRS, 31, 1) /* only in sstatus */
#define CR_STATUS_PIE R_CR_STATUS_PIE_MASK
#define CR_STATUS_U R_CR_STATUS_U_MASK
@@ -121,6 +122,7 @@ FIELD(CR_STATUS, RSIE, 23, 1)
#define CR_STATUS_IH R_CR_STATUS_IH_MASK
#define CR_STATUS_NMI R_CR_STATUS_NMI_MASK
#define CR_STATUS_RSIE R_CR_STATUS_RSIE_MASK
+#define CR_STATUS_SRS R_CR_STATUS_SRS_MASK
FIELD(CR_EXCEPTION, CAUSE, 2, 5)
FIELD(CR_EXCEPTION, ECCFTL, 31, 1)
@@ -234,6 +236,12 @@ struct ArchCPU {
/* Bits within each control register which are reserved or readonly. */
ControlRegState cr_state[NUM_CR_REGS];
+
+ /* External Interrupt Controller Interface */
+ uint32_t rha; /* Requested handler address */
+ uint32_t ril; /* Requested interrupt level */
+ uint32_t rrs; /* Requested register set */
+ bool rnmi; /* Requested nonmaskable interrupt */
};
@@ -63,7 +63,19 @@ static void nios2_cpu_reset(DeviceState *dev)
}
#ifndef CONFIG_USER_ONLY
-static void nios2_cpu_set_irq(void *opaque, int irq, int level)
+static void eic_set_irq(void *opaque, int irq, int level)
+{
+ Nios2CPU *cpu = opaque;
+ CPUState *cs = CPU(cpu);
+
+ if (level) {
+ cpu_interrupt(cs, CPU_INTERRUPT_HARD);
+ } else {
+ cpu_reset_interrupt(cs, CPU_INTERRUPT_HARD);
+ }
+}
+
+static void iic_set_irq(void *opaque, int irq, int level)
{
Nios2CPU *cpu = opaque;
CPUNios2State *env = &cpu->env;
@@ -87,15 +99,6 @@ static void nios2_cpu_initfn(Object *obj)
#if !defined(CONFIG_USER_ONLY)
mmu_init(&cpu->env);
-
- /*
- * These interrupt lines model the IIC (internal interrupt
- * controller). QEMU does not currently support the EIC
- * (external interrupt controller) -- if we did it would be
- * a separate device in hw/intc with a custom interface to
- * the CPU, and boards using it would not wire up these IRQ lines.
- */
- qdev_init_gpio_in_named(DEVICE(cpu), nios2_cpu_set_irq, "IRQ", 32);
#endif
}
@@ -128,10 +131,18 @@ static void realize_cr_status(CPUState *cs)
RO_REG(CR_EXCEPTION);
WR_REG(CR_BADADDR);
- /* TODO: These control registers are not present with the EIC. */
- RO_FIELD(CR_STATUS, RSIE);
- WR_REG(CR_IENABLE);
- RO_REG(CR_IPENDING);
+ if (cpu->eic_present) {
+ WR_FIELD(CR_STATUS, RSIE);
+ RO_FIELD(CR_STATUS, NMI);
+ WR_FIELD(CR_STATUS, PRS);
+ RO_FIELD(CR_STATUS, CRS);
+ WR_FIELD(CR_STATUS, IL);
+ WR_FIELD(CR_STATUS, IH);
+ } else {
+ RO_FIELD(CR_STATUS, RSIE);
+ WR_REG(CR_IENABLE);
+ RO_REG(CR_IPENDING);
+ }
if (cpu->mmu_present) {
WR_FIELD(CR_STATUS, U);
@@ -170,6 +181,14 @@ static void nios2_cpu_realizefn(DeviceState *dev, Error **errp)
Nios2CPUClass *ncc = NIOS2_CPU_GET_CLASS(dev);
Error *local_err = NULL;
+#ifndef CONFIG_USER_ONLY
+ if (cpu->eic_present) {
+ qdev_init_gpio_in_named(DEVICE(cpu), eic_set_irq, "EIC", 1);
+ } else {
+ qdev_init_gpio_in_named(DEVICE(cpu), iic_set_irq, "IRQ", 32);
+ }
+#endif
+
cpu_exec_realizefn(cs, &local_err);
if (local_err != NULL) {
error_propagate(errp, local_err);
@@ -187,17 +206,48 @@ static void nios2_cpu_realizefn(DeviceState *dev, Error **errp)
}
#ifndef CONFIG_USER_ONLY
+static bool eic_take_interrupt(Nios2CPU *cpu)
+{
+ CPUNios2State *env = &cpu->env;
+ const uint32_t status = env->ctrl[CR_STATUS];
+
+ if (cpu->rnmi) {
+ return !(status & CR_STATUS_NMI);
+ }
+ if (!(status & CR_STATUS_PIE)) {
+ return false;
+ }
+ if (cpu->ril <= FIELD_EX32(status, CR_STATUS, IL)) {
+ return false;
+ }
+ if (cpu->rrs != FIELD_EX32(status, CR_STATUS, CRS)) {
+ return true;
+ }
+ return status & CR_STATUS_RSIE;
+}
+
+static bool iic_take_interrupt(Nios2CPU *cpu)
+{
+ CPUNios2State *env = &cpu->env;
+
+ if (!(env->ctrl[CR_STATUS] & CR_STATUS_PIE)) {
+ return false;
+ }
+ return env->ctrl[CR_IPENDING] & env->ctrl[CR_IENABLE];
+}
+
static bool nios2_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
- CPUNios2State *env = &cpu->env;
- if ((interrupt_request & CPU_INTERRUPT_HARD) &&
- (env->ctrl[CR_STATUS] & CR_STATUS_PIE) &&
- (env->ctrl[CR_IPENDING] & env->ctrl[CR_IENABLE])) {
- cs->exception_index = EXCP_IRQ;
- nios2_cpu_do_interrupt(cs);
- return true;
+ if (interrupt_request & CPU_INTERRUPT_HARD) {
+ if (cpu->eic_present
+ ? eic_take_interrupt(cpu)
+ : iic_take_interrupt(cpu)) {
+ cs->exception_index = EXCP_IRQ;
+ nios2_cpu_do_interrupt(cs);
+ return true;
+ }
}
return false;
}
@@ -37,6 +37,10 @@ static void do_exception(Nios2CPU *cpu, uint32_t exception_addr,
uint32_t old_status = env->ctrl[CR_STATUS];
uint32_t new_status = old_status;
+ /* With shadow regs, exceptions are always taken into CRS 0. */
+ new_status &= ~R_CR_STATUS_CRS_MASK;
+ env->regs = env->shadow_regs[0];
+
if ((old_status & CR_STATUS_EH) == 0) {
int r_ea = R_EA, cr_es = CR_ESTATUS;
@@ -60,6 +64,14 @@ static void do_exception(Nios2CPU *cpu, uint32_t exception_addr,
CR_TLBMISC_DBL);
env->ctrl[CR_TLBMISC] |= tlbmisc_set;
}
+
+ /*
+ * With shadow regs, and EH == 0, PRS is set from CRS.
+ * At least, so says Table 3-9, and some other text,
+ * though Table 3-38 says otherwise.
+ */
+ new_status = FIELD_DP32(new_status, CR_STATUS, PRS,
+ FIELD_EX32(old_status, CR_STATUS, CRS));
}
new_status &= ~(CR_STATUS_PIE | CR_STATUS_U);
@@ -77,6 +89,39 @@ static void do_iic_irq(Nios2CPU *cpu)
do_exception(cpu, cpu->exception_addr, 0, false);
}
+static void do_eic_irq(Nios2CPU *cpu)
+{
+ CPUNios2State *env = &cpu->env;
+ uint32_t old_status = env->ctrl[CR_STATUS];
+ uint32_t new_status = old_status;
+ uint32_t old_rs = FIELD_EX32(old_status, CR_STATUS, CRS);
+ uint32_t new_rs = cpu->rrs;
+
+ new_status = FIELD_DP32(new_status, CR_STATUS, CRS, new_rs);
+ new_status = FIELD_DP32(new_status, CR_STATUS, IL, cpu->ril);
+ new_status = FIELD_DP32(new_status, CR_STATUS, NMI, cpu->rnmi);
+ new_status &= ~(CR_STATUS_RSIE | CR_STATUS_U);
+ new_status |= CR_STATUS_IH;
+
+ if (!(new_status & CR_STATUS_EH)) {
+ new_status = FIELD_DP32(new_status, CR_STATUS, PRS, old_rs);
+ if (new_rs == 0) {
+ env->ctrl[CR_ESTATUS] = old_status;
+ } else {
+ if (new_rs != old_rs) {
+ old_status |= CR_STATUS_SRS;
+ }
+ env->shadow_regs[new_rs][R_SSTATUS] = old_status;
+ }
+ env->shadow_regs[new_rs][R_EA] = env->pc + 4;
+ }
+
+ env->ctrl[CR_STATUS] = new_status;
+ nios2_update_crs(env);
+
+ env->pc = cpu->rha;
+}
+
void nios2_cpu_do_interrupt(CPUState *cs)
{
Nios2CPU *cpu = NIOS2_CPU(cs);
@@ -142,7 +187,11 @@ void nios2_cpu_do_interrupt(CPUState *cs)
switch (cs->exception_index) {
case EXCP_IRQ:
- do_iic_irq(cpu);
+ if (cpu->eic_present) {
+ do_eic_irq(cpu);
+ } else {
+ do_iic_irq(cpu);
+ }
break;
case EXCP_TLB_D: