On 15/08/2022 19:39, Fabiano Rosas wrote:
Matheus Ferst <matheus.fe...@eldorado.org.br> writes:
Create an interrupt masking method for the POWER9 and POWER10
processors. The new method is based on cpu_has_work_POWER{9,10} and
ppc_pending_interrupt_legacy.
Signed-off-by: Matheus Ferst <matheus.fe...@eldorado.org.br>
---
target/ppc/excp_helper.c | 160 +++++++++++++++++++++++++++++++++++++++
1 file changed, 160 insertions(+)
diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index 59981efd16..2ca6a917b2 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -1678,6 +1678,163 @@ void ppc_cpu_do_interrupt(CPUState *cs)
powerpc_excp(cpu, cs->exception_index);
}
+static int ppc_pending_interrupt_p9(CPUPPCState *env)
+{
+ CPUState *cs = env_cpu(env);
+ bool async_deliver = false;
I would suggest this to disentangle the PM stuff from MSR_EE:
if (cs->halted) {
if (env->spr[SPR_PSSCR] & PSSCR_EC) {
return p9_interrupt_powersave();
} else {
/*
* If EC is clear, any system-caused exception exits
* power-saving mode.
*/
ignore_msr_ee = true;
}
}
RESET (keep it duplicated)
MCHECK
if (!MSR_EE && !ignore_msr_ee) {
return 0;
}
MSR_EE interrupts
---
+
+ /* External reset */
+ if (env->pending_interrupts & PPC_INTERRUPT_RESET) {
+ return PPC_INTERRUPT_RESET;
+ }
+
+ if (cs->halted) {
+ uint64_t psscr = env->spr[SPR_PSSCR];
+
+ if (!(psscr & PSSCR_EC)) {
+ /* If EC is clear, return any system-caused interrupt */
+ async_deliver = true;
This doesn't look correct, look at what the ISA says:
EC=0
Hardware will exit power-saving mode when the exception corresponding
to any system-caused interrupt occurs. Power-saving mode is exited
either at the instruction following the stop (if MSR_EE=0) or in the
corresponding interrupt handler (if MSR_EE=1).
So with MSR_EE=0 we should *not* deliver any interrupts, but return to NIP+4.
At first, I thought the powerpc_excp would handle that but looking again
at the code, that's not how we return to NIP+4. We want to return true
in cs->has_work even if no interrupt can be delivered, so
cpu_thread_is_idle returns false, and we return from qemu_wait_io_event
to another iteration of the loop in mttcg_cpu_thread_fn.
I think we have two options here:
i) Keep ignoring MSR[EE] here when !PSSCR[EC] and prevent the delivery
in ppc_hw_interrupt if !MSR[EE]. That way, we can still use
ppc_pending_interrupt to set CPU_INTERRUPT_HARD in ppc_set_irq in patch 12.
ii) Don't return interrupts that require MSR[EE] set and ignore
CPU_INTERRUPT_HARD if cs->halted==1 in cpu_has_work_POWER*. In this
case, we wouldn't be able to merge the cpu_has_work_* implementations in
patch 13.
+ } else {
+ /* External Exception */
+ if ((env->pending_interrupts & PPC_INTERRUPT_EXT) &&
+ (env->spr[SPR_LPCR] & LPCR_EEE)) {
+ bool heic = !!(env->spr[SPR_LPCR] & LPCR_HEIC);
+ if (!heic || !FIELD_EX64_HV(env->msr) ||
+ FIELD_EX64(env->msr, MSR, PR)) {
+ return PPC_INTERRUPT_EXT;
+ }
+ }
+ /* Decrementer Exception */
+ if ((env->pending_interrupts & PPC_INTERRUPT_DECR) &&
+ (env->spr[SPR_LPCR] & LPCR_DEE)) {
+ return PPC_INTERRUPT_DECR;
+ }
+ /* Machine Check or Hypervisor Maintenance Exception */
+ if (env->spr[SPR_LPCR] & LPCR_OEE) {
+ if (env->pending_interrupts & PPC_INTERRUPT_MCK) {
+ return PPC_INTERRUPT_MCK;
+ }
+ if (env->pending_interrupts & PPC_INTERRUPT_HMI) {
+ return PPC_INTERRUPT_HMI;
+ }
+ }
+ /* Privileged Doorbell Exception */
+ if ((env->pending_interrupts & PPC_INTERRUPT_DOORBELL) &&
+ (env->spr[SPR_LPCR] & LPCR_PDEE)) {
+ return PPC_INTERRUPT_DOORBELL;
+ }
+ /* Hypervisor Doorbell Exception */
+ if ((env->pending_interrupts & PPC_INTERRUPT_HDOORBELL) &&
+ (env->spr[SPR_LPCR] & LPCR_HDEE)) {
+ return PPC_INTERRUPT_HDOORBELL;
+ }
+ /* Hypervisor virtualization exception */
+ if ((env->pending_interrupts & PPC_INTERRUPT_HVIRT) &&
+ (env->spr[SPR_LPCR] & LPCR_HVEE)) {
+ return PPC_INTERRUPT_HVIRT;
+ }
+ return 0;
+ }
+ }
+
+ /* Machine check exception */
+ if (env->pending_interrupts & PPC_INTERRUPT_MCK) {
+ return PPC_INTERRUPT_MCK;
+ }
+
+ /*
+ * For interrupts that gate on MSR:EE, we need to do something a
+ * bit more subtle, as we need to let them through even when EE is
+ * clear when coming out of some power management states (in order
+ * for them to become a 0x100).
+ */
+ async_deliver |= FIELD_EX64(env->msr, MSR, EE) || env->resume_as_sreset;
+
+ /* Hypervisor decrementer exception */
+ if (env->pending_interrupts & PPC_INTERRUPT_HDECR) {
+ /* LPCR will be clear when not supported so this will work */
+ bool hdice = !!(env->spr[SPR_LPCR] & LPCR_HDICE);
+ if ((async_deliver || !FIELD_EX64_HV(env->msr)) && hdice) {
+ /* HDEC clears on delivery */
+ return PPC_INTERRUPT_HDECR;
+ }
+ }
+
+ /* Hypervisor virtualization interrupt */
+ if (env->pending_interrupts & PPC_INTERRUPT_HVIRT) {
+ /* LPCR will be clear when not supported so this will work */
+ bool hvice = !!(env->spr[SPR_LPCR] & LPCR_HVICE);
+ if ((async_deliver || !FIELD_EX64_HV(env->msr)) && hvice) {
+ return PPC_INTERRUPT_HVIRT;
+ }
+ }
+
+ /* External interrupt can ignore MSR:EE under some circumstances */
+ if (env->pending_interrupts & PPC_INTERRUPT_EXT) {
+ bool lpes0 = !!(env->spr[SPR_LPCR] & LPCR_LPES0);
+ bool heic = !!(env->spr[SPR_LPCR] & LPCR_HEIC);
+ /* HEIC blocks delivery to the hypervisor */
+ if ((async_deliver && !(heic && FIELD_EX64_HV(env->msr) &&
+ !FIELD_EX64(env->msr, MSR, PR))) ||
+ (env->has_hv_mode && !FIELD_EX64_HV(env->msr) && !lpes0)) {
+ return PPC_INTERRUPT_EXT;
+ }
+ }
+ if (FIELD_EX64(env->msr, MSR, CE)) {
+ /* External critical interrupt */
+ if (env->pending_interrupts & PPC_INTERRUPT_CEXT) {
+ return PPC_INTERRUPT_CEXT;
+ }
+ }
+ if (async_deliver != 0) {
+ /* Watchdog timer on embedded PowerPC */
+ if (env->pending_interrupts & PPC_INTERRUPT_WDT) {
+ return PPC_INTERRUPT_WDT;
+ }
+ if (env->pending_interrupts & PPC_INTERRUPT_CDOORBELL) {
+ return PPC_INTERRUPT_CDOORBELL;
+ }
+ /* Fixed interval timer on embedded PowerPC */
+ if (env->pending_interrupts & PPC_INTERRUPT_FIT) {
+ return PPC_INTERRUPT_FIT;
+ }
+ /* Programmable interval timer on embedded PowerPC */
+ if (env->pending_interrupts & PPC_INTERRUPT_PIT) {
+ return PPC_INTERRUPT_PIT;
+ }
+ /* Decrementer exception */
+ if (env->pending_interrupts & PPC_INTERRUPT_DECR) {
+ return PPC_INTERRUPT_DECR;
+ }
+ if (env->pending_interrupts & PPC_INTERRUPT_DOORBELL) {
+ return PPC_INTERRUPT_DOORBELL;
+ }
+ if (env->pending_interrupts & PPC_INTERRUPT_HDOORBELL) {
+ return PPC_INTERRUPT_HDOORBELL;
+ }
+ if (env->pending_interrupts & PPC_INTERRUPT_PERFM) {
+ return PPC_INTERRUPT_PERFM;
+ }
+ /* Thermal interrupt */
+ if (env->pending_interrupts & PPC_INTERRUPT_THERM) {
+ return PPC_INTERRUPT_THERM;
+ }
+ /* EBB exception */
+ if (env->pending_interrupts & PPC_INTERRUPT_EBB) {
+ /*
+ * EBB exception must be taken in problem state and
+ * with BESCR_GE set.
+ */
+ if (FIELD_EX64(env->msr, MSR, PR) &&
+ (env->spr[SPR_BESCR] & BESCR_GE)) {
+ return PPC_INTERRUPT_EBB;
+ }
+ }
+ }
+
+ return 0;
+}
+
static int ppc_pending_interrupt_legacy(CPUPPCState *env)
{
bool async_deliver;
@@ -1793,6 +1950,9 @@ static int ppc_pending_interrupt_legacy(CPUPPCState *env)
static int ppc_pending_interrupt(CPUPPCState *env)
{
switch (env->excp_model) {
+ case POWERPC_EXCP_POWER9:
+ case POWERPC_EXCP_POWER10:
+ return ppc_pending_interrupt_p9(env);
default:
return ppc_pending_interrupt_legacy(env);
}
Thanks,
Matheus K. Ferst
Instituto de Pesquisas ELDORADO <http://www.eldorado.org.br/>
Analista de Software
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