[PATCH 4/8] squash target/ppc: Introduce powerpc_excp_40x

From: Fabiano Rosas <farosas@linux.ibm.com>
To: qemu-devel@nongnu.org
Cc: richard.henderson@linaro.org, danielhb413@gmail.com,
	qemu-ppc@nongnu.org, clg@kaod.org, david@gibson.dropbear.id.au
Subject: [PATCH 4/8] squash target/ppc: Introduce powerpc_excp_40x
Date: Mon, 10 Jan 2022 15:15:42 -0300	[thread overview]
Message-ID: <20220110181546.4131853-5-farosas@linux.ibm.com> (raw)
In-Reply-To: <20220110181546.4131853-1-farosas@linux.ibm.com>

Introduce a new exception dispatcher for 40x CPUs.

Differences from the generic powerpc_excp code:

- Not BookE, so some MSR bits are cleared at interrupt dispatch;
- No MSR_HV or MSR_LE;
- No power saving states;
- No Hypervisor Emulation Assistance;
- Not 64 bits;
- No System call vectored;
- No Interrupts Little Endian;
- No Alternate Interrupt Location.

Exceptions used:

POWERPC_EXCP_ALIGN
POWERPC_EXCP_APU
POWERPC_EXCP_CRITICAL
POWERPC_EXCP_DEBUG
POWERPC_EXCP_DSI
POWERPC_EXCP_DTLB
POWERPC_EXCP_EXTERNAL
POWERPC_EXCP_FIT
POWERPC_EXCP_FPU
POWERPC_EXCP_ISI
POWERPC_EXCP_ITLB
POWERPC_EXCP_MCHECK
POWERPC_EXCP_PIT
POWERPC_EXCP_PROGRAM
POWERPC_EXCP_SYSCALL
POWERPC_EXCP_WDT

Signed-off-by: Fabiano Rosas <farosas@linux.ibm.com>
---
 target/ppc/excp_helper.c | 165 +++------------------------------------
 1 file changed, 13 insertions(+), 152 deletions(-)

diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c
index 12ab5e1b34..1d997c4d6b 100644
--- a/target/ppc/excp_helper.c
+++ b/target/ppc/excp_helper.c
@@ -409,54 +409,18 @@ static void powerpc_excp_40x(PowerPCCPU *cpu, int excp)
                   excp, env->error_code);
 
     /* new srr1 value excluding must-be-zero bits */
-    if (excp_model == POWERPC_EXCP_BOOKE) {
-        msr = env->msr;
-    } else {
-        msr = env->msr & ~0x783f0000ULL;
-    }
+    msr = env->msr & ~0x783f0000ULL;
 
     /*
-     * new interrupt handler msr preserves existing HV and ME unless
-     * explicitly overriden
+     * new interrupt handler msr preserves existing ME unless
+     * explicitly overriden.
      */
-    new_msr = env->msr & (((target_ulong)1 << MSR_ME) | MSR_HVB);
+    new_msr = env->msr & (((target_ulong)1 << MSR_ME));
 
     /* target registers */
     srr0 = SPR_SRR0;
     srr1 = SPR_SRR1;
 
-    /*
-     * check for special resume at 0x100 from doze/nap/sleep/winkle on
-     * P7/P8/P9
-     */
-    if (env->resume_as_sreset) {
-        excp = powerpc_reset_wakeup(cs, env, excp, &msr);
-    }
-
-    /*
-     * Hypervisor emulation assistance interrupt only exists on server
-     * arch 2.05 server or later. We also don't want to generate it if
-     * we don't have HVB in msr_mask (PAPR mode).
-     */
-    if (excp == POWERPC_EXCP_HV_EMU
-#if defined(TARGET_PPC64)
-        && !(mmu_is_64bit(env->mmu_model) && (env->msr_mask & MSR_HVB))
-#endif /* defined(TARGET_PPC64) */
-
-    ) {
-        excp = POWERPC_EXCP_PROGRAM;
-    }
-
-#ifdef TARGET_PPC64
-    /*
-     * SPEU and VPU share the same IVOR but they exist in different
-     * processors. SPEU is e500v1/2 only and VPU is e6500 only.
-     */
-    if (excp_model == POWERPC_EXCP_BOOKE && excp == POWERPC_EXCP_VPU) {
-        excp = POWERPC_EXCP_SPEU;
-    }
-#endif
-
     vector = env->excp_vectors[excp];
     if (vector == (target_ulong)-1ULL) {
         cpu_abort(cs, "Raised an exception without defined vector %d\n",
@@ -581,6 +545,11 @@ static void powerpc_excp_40x(PowerPCCPU *cpu, int excp)
          */
         env->spr[SPR_DSISR] |= (env->error_code & 0x03FF0000) >> 16;
         break;
+    case POWERPC_EXCP_HV_EMU:
+        /*
+         * Hypervisor emulation assistance interrupt only exists on server
+         * arch 2.05 server or later.
+         */
     case POWERPC_EXCP_PROGRAM:   /* Program exception                        */
         switch (env->error_code & ~0xF) {
         case POWERPC_EXCP_FP:
@@ -645,22 +614,8 @@ static void powerpc_excp_40x(PowerPCCPU *cpu, int excp)
             new_msr |= (target_ulong)MSR_HVB;
         }
         break;
-    case POWERPC_EXCP_SYSCALL_VECTORED: /* scv exception                     */
-        lev = env->error_code;
-        dump_syscall(env);
-        env->nip += 4;
-        new_msr |= env->msr & ((target_ulong)1 << MSR_EE);
-        new_msr |= env->msr & ((target_ulong)1 << MSR_RI);
-
-        vector += lev * 0x20;
-
-        env->lr = env->nip;
-        env->ctr = msr;
-        break;
     case POWERPC_EXCP_FPU:       /* Floating-point unavailable exception     */
     case POWERPC_EXCP_APU:       /* Auxiliary processor unavailable          */
-    case POWERPC_EXCP_DECR:      /* Decrementer exception                    */
-        break;
     case POWERPC_EXCP_FIT:       /* Fixed-interval timer interrupt           */
         /* FIT on 4xx */
         trace_ppc_excp_print("FIT");
@@ -693,70 +648,6 @@ static void powerpc_excp_40x(PowerPCCPU *cpu, int excp)
             cpu_abort(cs, "Debug exception triggered on unsupported model\n");
         }
         break;
-    case POWERPC_EXCP_SPEU:   /* SPE/embedded floating-point unavailable/VPU  */
-        env->spr[SPR_BOOKE_ESR] = ESR_SPV;
-        break;
-    case POWERPC_EXCP_DOORI:     /* Embedded doorbell interrupt              */
-        break;
-    case POWERPC_EXCP_DOORCI:    /* Embedded doorbell critical interrupt     */
-        srr0 = SPR_BOOKE_CSRR0;
-        srr1 = SPR_BOOKE_CSRR1;
-        break;
-    case POWERPC_EXCP_RESET:     /* System reset exception                   */
-        /* A power-saving exception sets ME, otherwise it is unchanged */
-        if (msr_pow) {
-            /* indicate that we resumed from power save mode */
-            msr |= 0x10000;
-            new_msr |= ((target_ulong)1 << MSR_ME);
-        }
-        if (env->msr_mask & MSR_HVB) {
-            /*
-             * ISA specifies HV, but can be delivered to guest with HV
-             * clear (e.g., see FWNMI in PAPR, NMI injection in QEMU).
-             */
-            new_msr |= (target_ulong)MSR_HVB;
-        } else {
-            if (msr_pow) {
-                cpu_abort(cs, "Trying to deliver power-saving system reset "
-                          "exception %d with no HV support\n", excp);
-            }
-        }
-        break;
-    case POWERPC_EXCP_DSEG:      /* Data segment exception                   */
-    case POWERPC_EXCP_ISEG:      /* Instruction segment exception            */
-    case POWERPC_EXCP_TRACE:     /* Trace exception                          */
-        break;
-    case POWERPC_EXCP_HISI:      /* Hypervisor instruction storage exception */
-        msr |= env->error_code;
-        /* fall through */
-    case POWERPC_EXCP_HDECR:     /* Hypervisor decrementer exception         */
-    case POWERPC_EXCP_HDSI:      /* Hypervisor data storage exception        */
-    case POWERPC_EXCP_HDSEG:     /* Hypervisor data segment exception        */
-    case POWERPC_EXCP_HISEG:     /* Hypervisor instruction segment exception */
-    case POWERPC_EXCP_SDOOR_HV:  /* Hypervisor Doorbell interrupt            */
-    case POWERPC_EXCP_HV_EMU:
-    case POWERPC_EXCP_HVIRT:     /* Hypervisor virtualization                */
-        srr0 = SPR_HSRR0;
-        srr1 = SPR_HSRR1;
-        new_msr |= (target_ulong)MSR_HVB;
-        new_msr |= env->msr & ((target_ulong)1 << MSR_RI);
-        break;
-    case POWERPC_EXCP_VPU:       /* Vector unavailable exception             */
-    case POWERPC_EXCP_VSXU:       /* VSX unavailable exception               */
-    case POWERPC_EXCP_FU:         /* Facility unavailable exception          */
-#ifdef TARGET_PPC64
-        env->spr[SPR_FSCR] |= ((target_ulong)env->error_code << 56);
-#endif
-        break;
-    case POWERPC_EXCP_HV_FU:     /* Hypervisor Facility Unavailable Exception */
-#ifdef TARGET_PPC64
-        env->spr[SPR_HFSCR] |= ((target_ulong)env->error_code << FSCR_IC_POS);
-        srr0 = SPR_HSRR0;
-        srr1 = SPR_HSRR1;
-        new_msr |= (target_ulong)MSR_HVB;
-        new_msr |= env->msr & ((target_ulong)1 << MSR_RI);
-#endif
-        break;
     case POWERPC_EXCP_PIT:       /* Programmable interval timer interrupt    */
         trace_ppc_excp_print("PIT");
         break;
@@ -824,41 +715,11 @@ static void powerpc_excp_40x(PowerPCCPU *cpu, int excp)
         }
     }
 
-    /*
-     * Sort out endianness of interrupt, this differs depending on the
-     * CPU, the HV mode, etc...
-     */
-    if (ppc_interrupts_little_endian(cpu, !!(new_msr & MSR_HVB))) {
-        new_msr |= (target_ulong)1 << MSR_LE;
-    }
+    /* Save PC */
+    env->spr[srr0] = env->nip;
 
-#if defined(TARGET_PPC64)
-    if (excp_model == POWERPC_EXCP_BOOKE) {
-        if (env->spr[SPR_BOOKE_EPCR] & EPCR_ICM) {
-            /* Cat.64-bit: EPCR.ICM is copied to MSR.CM */
-            new_msr |= (target_ulong)1 << MSR_CM;
-        } else {
-            vector = (uint32_t)vector;
-        }
-    } else {
-        if (!msr_isf && !mmu_is_64bit(env->mmu_model)) {
-            vector = (uint32_t)vector;
-        } else {
-            new_msr |= (target_ulong)1 << MSR_SF;
-        }
-    }
-#endif
-
-    if (excp != POWERPC_EXCP_SYSCALL_VECTORED) {
-        /* Save PC */
-        env->spr[srr0] = env->nip;
-
-        /* Save MSR */
-        env->spr[srr1] = msr;
-    }
-
-    /* This can update new_msr and vector if AIL applies */
-    ppc_excp_apply_ail(cpu, excp_model, excp, msr, &new_msr, &vector);
+    /* Save MSR */
+    env->spr[srr1] = msr;
 
     powerpc_set_excp_state(cpu, vector, new_msr);
 }
-- 
2.33.1


