Re: [RFC PATCH v2 13/29] target/ppc: remove unused interrupts from p8_pending_interrupt

[Matheus K. Ferst]

On 27/09/2022 19:14, Fabiano Rosas wrote:

Matheus Ferst  writes:


Remove the following unused interrupts from the POWER8 interrupt masking
method:
- PPC_INTERRUPT_RESET: only raised for 6xx, 7xx, 970, and POWER5p;
- Debug Interrupt: removed in Power ISA v2.07;
- Hypervisor Virtualization: introduced in Power ISA v3.0;
- Critical Input, Watchdog Timer, and Fixed Interval Timer: only defined
   for embedded CPUs;
- Hypervisor Doorbell, Doorbell, and Critical Doorbell: processor does


We still need the first two.
0xe80 - Directed hypervisor doorbell
0xa00 - Directed privileged doorbell



It seems that on PowerISA v2.07, the category for msgsnd and msgclr 
became "Embedded Processor Control" or "Book S." That's certainly not 
what we are doing in code, both instructions are behind the PPC2_PRCNTL 
flag, so they are not available for -cpu POWER8. Also, we're not 
checking for ISA 3.00 on msgsync... I'll keep these interrupts in v3 and 
send a separate patch fixing the instruction flags.


Thanks,
Matheus K. Ferst
Instituto de Pesquisas ELDORADO 
Analista de Software
Aviso Legal - Disclaimer 

Re: [RFC PATCH v2 13/29] target/ppc: remove unused interrupts from p8_pending_interrupt

[Fabiano Rosas]

Matheus Ferst  writes:

> Remove the following unused interrupts from the POWER8 interrupt masking
> method:
> - PPC_INTERRUPT_RESET: only raised for 6xx, 7xx, 970, and POWER5p;
> - Debug Interrupt: removed in Power ISA v2.07;
> - Hypervisor Virtualization: introduced in Power ISA v3.0;
> - Critical Input, Watchdog Timer, and Fixed Interval Timer: only defined
>   for embedded CPUs;
> - Hypervisor Doorbell, Doorbell, and Critical Doorbell: processor does

We still need the first two.
0xe80 - Directed hypervisor doorbell
0xa00 - Directed privileged doorbell

>   not implement the "Embedded.Processor Control" category;
> - Programmable Interval Timer: 40x-only;
> - PPC_INTERRUPT_THERM: only raised for 970 and POWER5p;
>

[RFC PATCH v2 13/29] target/ppc: remove unused interrupts from p8_pending_interrupt

[Matheus Ferst]

Remove the following unused interrupts from the POWER8 interrupt masking
method:
- PPC_INTERRUPT_RESET: only raised for 6xx, 7xx, 970, and POWER5p;
- Debug Interrupt: removed in Power ISA v2.07;
- Hypervisor Virtualization: introduced in Power ISA v3.0;
- Critical Input, Watchdog Timer, and Fixed Interval Timer: only defined
  for embedded CPUs;
- Hypervisor Doorbell, Doorbell, and Critical Doorbell: processor does
  not implement the "Embedded.Processor Control" category;
- Programmable Interval Timer: 40x-only;
- PPC_INTERRUPT_THERM: only raised for 970 and POWER5p;

Signed-off-by: Matheus Ferst 
---
v2:
  - Remove CDOORBELL and THERM interrupts (farosas);
  - Also remove RESET, DEBUG, DOORBELL, and HDOORBELL interrupts;
  - Assert for the removed interrupts.
---
 target/ppc/excp_helper.c | 58 ++--
 1 file changed, 8 insertions(+), 50 deletions(-)

diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index f60d9826d8..6ab03b2e12 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -1679,24 +1679,22 @@ void ppc_cpu_do_interrupt(CPUState *cs)
 }
 
 #if defined(TARGET_PPC64)
+#define P8_UNUSED_INTERRUPTS \
+(PPC_INTERRUPT_RESET | PPC_INTERRUPT_DEBUG | PPC_INTERRUPT_HVIRT |  \
+PPC_INTERRUPT_CEXT | PPC_INTERRUPT_WDT | PPC_INTERRUPT_CDOORBELL |  \
+PPC_INTERRUPT_FIT | PPC_INTERRUPT_PIT | PPC_INTERRUPT_DOORBELL |\
+PPC_INTERRUPT_HDOORBELL | PPC_INTERRUPT_THERM)
+
 static int p8_next_unmasked_interrupt(CPUPPCState *env)
 {
 bool async_deliver;
 
-/* External reset */
-if (env->pending_interrupts & PPC_INTERRUPT_RESET) {
-return PPC_INTERRUPT_RESET;
-}
+assert((env->pending_interrupts & P8_UNUSED_INTERRUPTS) == 0);
+
 /* Machine check exception */
 if (env->pending_interrupts & PPC_INTERRUPT_MCK) {
 return PPC_INTERRUPT_MCK;
 }
-#if 0 /* TODO */
-/* External debug exception */
-if (env->pending_interrupts & PPC_INTERRUPT_DEBUG) {
-return PPC_INTERRUPT_DEBUG;
-}
-#endif
 
 /*
  * For interrupts that gate on MSR:EE, we need to do something a
@@ -1716,15 +1714,6 @@ static int p8_next_unmasked_interrupt(CPUPPCState *env)
 }
 }
 
-/* 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);
@@ -1736,45 +1725,14 @@ static int p8_next_unmasked_interrupt(CPUPPCState *env)
 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) {
 /*
-- 
2.25.1