[PATCH v4 6/9] target/ppc: optimize p7 exception handling routines

[Harsh Prateek Bora <harshpb@linux.ibm.com>]

Like p8 and p9, simplifying p7 exception handling rotuines to avoid
un-necessary multiple indirect accesses to env->pending_interrupts and
env->spr[SPR_LPCR].

Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
---
 target/ppc/excp_helper.c | 46 ++++++++++++++++++++++------------------
 1 file changed, 25 insertions(+), 21 deletions(-)

diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index c0828aac88..d0e0f609a0 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -1683,51 +1683,54 @@ void ppc_cpu_do_interrupt(CPUState *cs)
      PPC_INTERRUPT_PIT | PPC_INTERRUPT_DOORBELL | PPC_INTERRUPT_HDOORBELL | \
      PPC_INTERRUPT_THERM | PPC_INTERRUPT_EBB)
 
-static int p7_interrupt_powersave(CPUPPCState *env)
+static int p7_interrupt_powersave(uint32_t pending_interrupts,
+                                  target_ulong lpcr)
 {
-    if ((env->pending_interrupts & PPC_INTERRUPT_EXT) &&
-        (env->spr[SPR_LPCR] & LPCR_P7_PECE0)) {
+    if ((pending_interrupts & PPC_INTERRUPT_EXT) &&
+        (lpcr & LPCR_P7_PECE0)) {
         return PPC_INTERRUPT_EXT;
     }
-    if ((env->pending_interrupts & PPC_INTERRUPT_DECR) &&
-        (env->spr[SPR_LPCR] & LPCR_P7_PECE1)) {
+    if ((pending_interrupts & PPC_INTERRUPT_DECR) &&
+        (lpcr & LPCR_P7_PECE1)) {
         return PPC_INTERRUPT_DECR;
     }
-    if ((env->pending_interrupts & PPC_INTERRUPT_MCK) &&
-        (env->spr[SPR_LPCR] & LPCR_P7_PECE2)) {
+    if ((pending_interrupts & PPC_INTERRUPT_MCK) &&
+        (lpcr & LPCR_P7_PECE2)) {
         return PPC_INTERRUPT_MCK;
     }
-    if ((env->pending_interrupts & PPC_INTERRUPT_HMI) &&
-        (env->spr[SPR_LPCR] & LPCR_P7_PECE2)) {
+    if ((pending_interrupts & PPC_INTERRUPT_HMI) &&
+        (lpcr & LPCR_P7_PECE2)) {
         return PPC_INTERRUPT_HMI;
     }
-    if (env->pending_interrupts & PPC_INTERRUPT_RESET) {
+    if (pending_interrupts & PPC_INTERRUPT_RESET) {
         return PPC_INTERRUPT_RESET;
     }
     return 0;
 }
 
-static int p7_next_unmasked_interrupt(CPUPPCState *env)
+static int p7_next_unmasked_interrupt(CPUPPCState *env,
+                                      uint32_t pending_interrupts,
+                                      target_ulong lpcr)
 {
     CPUState *cs = env_cpu(env);
 
     /* Ignore MSR[EE] when coming out of some power management states */
     bool msr_ee = FIELD_EX64(env->msr, MSR, EE) || env->resume_as_sreset;
 
-    assert((env->pending_interrupts & P7_UNUSED_INTERRUPTS) == 0);
+    assert((pending_interrupts & P7_UNUSED_INTERRUPTS) == 0);
 
     if (cs->halted) {
         /* LPCR[PECE] controls which interrupts can exit power-saving mode */
-        return p7_interrupt_powersave(env);
+        return p7_interrupt_powersave(pending_interrupts, lpcr);
     }
 
     /* Machine check exception */
-    if (env->pending_interrupts & PPC_INTERRUPT_MCK) {
+    if (pending_interrupts & PPC_INTERRUPT_MCK) {
         return PPC_INTERRUPT_MCK;
     }
 
     /* Hypervisor decrementer exception */
-    if (env->pending_interrupts & PPC_INTERRUPT_HDECR) {
+    if (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 ((msr_ee || !FIELD_EX64_HV(env->msr)) && hdice) {
@@ -1737,9 +1740,9 @@ static int p7_next_unmasked_interrupt(CPUPPCState *env)
     }
 
     /* 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);
+    if (pending_interrupts & PPC_INTERRUPT_EXT) {
+        bool lpes0 = !!(lpcr & LPCR_LPES0);
+        bool heic = !!(lpcr & LPCR_HEIC);
         /* HEIC blocks delivery to the hypervisor */
         if ((msr_ee && !(heic && FIELD_EX64_HV(env->msr) &&
             !FIELD_EX64(env->msr, MSR, PR))) ||
@@ -1749,10 +1752,10 @@ static int p7_next_unmasked_interrupt(CPUPPCState *env)
     }
     if (msr_ee != 0) {
         /* Decrementer exception */
-        if (env->pending_interrupts & PPC_INTERRUPT_DECR) {
+        if (pending_interrupts & PPC_INTERRUPT_DECR) {
             return PPC_INTERRUPT_DECR;
         }
-        if (env->pending_interrupts & PPC_INTERRUPT_PERFM) {
+        if (pending_interrupts & PPC_INTERRUPT_PERFM) {
             return PPC_INTERRUPT_PERFM;
         }
     }
@@ -2022,7 +2025,8 @@ static int ppc_next_unmasked_interrupt(CPUPPCState *env)
 #ifdef TARGET_PPC64
     switch (env->excp_model) {
     case POWERPC_EXCP_POWER7:
-        return p7_next_unmasked_interrupt(env);
+        return p7_next_unmasked_interrupt(env, env->pending_interrupts,
+                                          env->spr[SPR_LPCR]);
     case POWERPC_EXCP_POWER8:
         return p8_next_unmasked_interrupt(env, env->pending_interrupts,
                                           env->spr[SPR_LPCR]);
-- 
2.45.2