target/ppc: Introduce prot_for_access_type

Use this in the three places we currently have a local array
indexed by rwx (which happens to have the same values).
The types will match up correctly with additional changes.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210518201146.794854-2-richard.henderson@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

target/ppc/internal.h

@@ -228,4 +228,23 @@ void destroy_ppc_opcodes(PowerPCCPU *cpu);
 void ppc_gdb_init(CPUState *cs, PowerPCCPUClass *ppc);
 gchar *ppc_gdb_arch_name(CPUState *cs);
 
+/**
+ * prot_for_access_type:
+ * @access_type: Access type
+ *
+ * Return the protection bit required for the given access type.
+ */
+static inline int prot_for_access_type(MMUAccessType access_type)
+{
+    switch (access_type) {
+    case MMU_INST_FETCH:
+        return PAGE_EXEC;
+    case MMU_DATA_LOAD:
+        return PAGE_READ;
+    case MMU_DATA_STORE:
+        return PAGE_WRITE;
+    }
+    g_assert_not_reached();
+}
+
 #endif /* PPC_INTERNAL_H */

target/ppc/mmu-hash32.c

@@ -24,6 +24,7 @@
 #include "exec/helper-proto.h"
 #include "sysemu/kvm.h"
 #include "kvm_ppc.h"
+#include "internal.h"
 #include "mmu-hash32.h"
 #include "exec/log.h"
 
@@ -421,10 +422,11 @@ int ppc_hash32_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
     hwaddr pte_offset;
     ppc_hash_pte32_t pte;
     int prot;
-    const int need_prot[] = {PAGE_READ, PAGE_WRITE, PAGE_EXEC};
+    int need_prot;
     hwaddr raddr;
 
     assert((rwx == 0) || (rwx == 1) || (rwx == 2));
+    need_prot = prot_for_access_type(rwx);
 
     /* 1. Handle real mode accesses */
     if (((rwx == 2) && (msr_ir == 0)) || ((rwx != 2) && (msr_dr == 0))) {
@@ -440,7 +442,7 @@ int ppc_hash32_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
     if (env->nb_BATs != 0) {
         raddr = ppc_hash32_bat_lookup(cpu, eaddr, rwx, &prot);
         if (raddr != -1) {
-            if (need_prot[rwx] & ~prot) {
+            if (need_prot & ~prot) {
                 if (rwx == 2) {
                     cs->exception_index = POWERPC_EXCP_ISI;
                     env->error_code = 0x08000000;
@@ -513,7 +515,7 @@ int ppc_hash32_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
 
     prot = ppc_hash32_pte_prot(cpu, sr, pte);
 
-    if (need_prot[rwx] & ~prot) {
+    if (need_prot & ~prot) {
         /* Access right violation */
         qemu_log_mask(CPU_LOG_MMU, "PTE access rejected\n");
         if (rwx == 2) {

target/ppc/mmu-hash64.c

@@ -29,6 +29,7 @@
 #include "mmu-hash64.h"
 #include "exec/log.h"
 #include "hw/hw.h"
+#include "internal.h"
 #include "mmu-book3s-v3.h"
 #include "helper_regs.h"
 
@@ -876,7 +877,7 @@ int ppc_hash64_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr,
     hwaddr ptex;
     ppc_hash_pte64_t pte;
     int exec_prot, pp_prot, amr_prot, prot;
-    const int need_prot[] = {PAGE_READ, PAGE_WRITE, PAGE_EXEC};
+    int need_prot;
     hwaddr raddr;
 
     assert((rwx == 0) || (rwx == 1) || (rwx == 2));
@@ -996,7 +997,8 @@ skip_slb_search:
     amr_prot = ppc_hash64_amr_prot(cpu, pte);
     prot = exec_prot & pp_prot & amr_prot;
 
-    if ((need_prot[rwx] & ~prot) != 0) {
+    need_prot = prot_for_access_type(rwx);
+    if (need_prot & ~prot) {
         /* Access right violation */
         qemu_log_mask(CPU_LOG_MMU, "PTE access rejected\n");
         if (rwx == 2) {
@@ -1012,13 +1014,13 @@ skip_slb_search:
             ppc_hash64_set_isi(cs, srr1);
         } else {
             int dsisr = 0;
-            if (need_prot[rwx] & ~pp_prot) {
+            if (need_prot & ~pp_prot) {
                 dsisr |= DSISR_PROTFAULT;
             }
             if (rwx == 1) {
                 dsisr |= DSISR_ISSTORE;
             }
-            if (need_prot[rwx] & ~amr_prot) {
+            if (need_prot & ~amr_prot) {
                 dsisr |= DSISR_AMR;
             }
             ppc_hash64_set_dsi(cs, eaddr, dsisr);

target/ppc/mmu-radix64.c

@@ -25,6 +25,7 @@
 #include "sysemu/kvm.h"
 #include "kvm_ppc.h"
 #include "exec/log.h"
+#include "internal.h"
 #include "mmu-radix64.h"
 #include "mmu-book3s-v3.h"
 
@@ -135,7 +136,7 @@ static bool ppc_radix64_check_prot(PowerPCCPU *cpu, int rwx, uint64_t pte,
                                    bool partition_scoped)
 {
     CPUPPCState *env = &cpu->env;
-    const int need_prot[] = { PAGE_READ, PAGE_WRITE, PAGE_EXEC };
+    int need_prot;
 
     /* Check Page Attributes (pte58:59) */
     if (((pte & R_PTE_ATT) == R_PTE_ATT_NI_IO) && (rwx == 2)) {
@@ -158,7 +159,8 @@ static bool ppc_radix64_check_prot(PowerPCCPU *cpu, int rwx, uint64_t pte,
     }
 
     /* Check if requested access type is allowed */
-    if (need_prot[rwx] & ~(*prot)) { /* Page Protected for that Access */
+    need_prot = prot_for_access_type(rwx);
+    if (need_prot & ~*prot) { /* Page Protected for that Access */
         *fault_cause |= DSISR_PROTFAULT;
         return true;
     }