target/ppc: Move 601 hflags adjustment to hreg_compute_hflags

Keep all hflags computation in one place, as this will be
especially important later.

Introduce a new POWERPC_FLAG_HID0_LE bit to indicate when
LE should be taken from HID0.  This appears to be set if
and only if POWERPC_FLAG_RTC_CLK is set, but we're not
short of bits and having both names will avoid confusion.

Note that this was the only user of hflags_nmsr, so we can
perform a straight assignment rather than mask and set.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20210315184615.1985590-3-richard.henderson@linaro.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

4 files changed, 18 insertions, 9 deletions

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index e73416da68..061d2eed1b 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -581,6 +581,8 @@ enum {
     POWERPC_FLAG_TM       = 0x00100000,
     /* Has SCV (ISA 3.00)                                                    */
     POWERPC_FLAG_SCV      = 0x00200000,
+    /* Has HID0 for LE bit (601)                                             */
+    POWERPC_FLAG_HID0_LE  = 0x00400000,
 };
 
 /*****************************************************************************/
diff --git a/target/ppc/helper_regs.c b/target/ppc/helper_regs.c
index 5e18232b84..95b9aca61f 100644
--- a/target/ppc/helper_regs.c
+++ b/target/ppc/helper_regs.c
@@ -96,8 +96,17 @@ void hreg_compute_hflags(CPUPPCState *env)
     hflags_mask |= (1ULL << MSR_CM) | (1ULL << MSR_SF) | MSR_HVB;
     hreg_compute_mem_idx(env);
     env->hflags = env->msr & hflags_mask;
-    /* Merge with hflags coming from other registers */
-    env->hflags |= env->hflags_nmsr;
+
+    if (env->flags & POWERPC_FLAG_HID0_LE) {
+        /*
+         * Note that MSR_LE is not set in env->msr_mask for this cpu,
+         * and so will never be set in msr or hflags at this point.
+         */
+        uint32_t le = extract32(env->spr[SPR_HID0], 3, 1);
+        env->hflags |= le << MSR_LE;
+        /* Retain for backward compatibility with migration. */
+        env->hflags_nmsr = le << MSR_LE;
+    }
 }
 
 void cpu_interrupt_exittb(CPUState *cs)
diff --git a/target/ppc/misc_helper.c b/target/ppc/misc_helper.c
index 5d6e0de396..63e3147eb4 100644
--- a/target/ppc/misc_helper.c
+++ b/target/ppc/misc_helper.c
@@ -194,16 +194,14 @@ void helper_store_hid0_601(CPUPPCState *env, target_ulong val)
     target_ulong hid0;
 
     hid0 = env->spr[SPR_HID0];
+    env->spr[SPR_HID0] = (uint32_t)val;
+
     if ((val ^ hid0) & 0x00000008) {
         /* Change current endianness */
-        env->hflags &= ~(1 << MSR_LE);
-        env->hflags_nmsr &= ~(1 << MSR_LE);
-        env->hflags_nmsr |= (1 << MSR_LE) & (((val >> 3) & 1) << MSR_LE);
-        env->hflags |= env->hflags_nmsr;
+        hreg_compute_hflags(env);
         qemu_log("%s: set endianness to %c => " TARGET_FMT_lx "\n", __func__,
                  val & 0x8 ? 'l' : 'b', env->hflags);
     }
-    env->spr[SPR_HID0] = (uint32_t)val;
 }
 
 void helper_store_403_pbr(CPUPPCState *env, uint32_t num, target_ulong value)
diff --git a/target/ppc/translate_init.c.inc b/target/ppc/translate_init.c.inc
index c03a7c4f52..049d76cfd1 100644
--- a/target/ppc/translate_init.c.inc
+++ b/target/ppc/translate_init.c.inc
@@ -5441,7 +5441,7 @@ POWERPC_FAMILY(601)(ObjectClass *oc, void *data)
     pcc->excp_model = POWERPC_EXCP_601;
     pcc->bus_model = PPC_FLAGS_INPUT_6xx;
     pcc->bfd_mach = bfd_mach_ppc_601;
-    pcc->flags = POWERPC_FLAG_SE | POWERPC_FLAG_RTC_CLK;
+    pcc->flags = POWERPC_FLAG_SE | POWERPC_FLAG_RTC_CLK | POWERPC_FLAG_HID0_LE;
 }
 
 #define POWERPC_MSRR_601v    (0x0000000000001040ULL)
@@ -5485,7 +5485,7 @@ POWERPC_FAMILY(601v)(ObjectClass *oc, void *data)
 #endif
     pcc->bus_model = PPC_FLAGS_INPUT_6xx;
     pcc->bfd_mach = bfd_mach_ppc_601;
-    pcc->flags = POWERPC_FLAG_SE | POWERPC_FLAG_RTC_CLK;
+    pcc->flags = POWERPC_FLAG_SE | POWERPC_FLAG_RTC_CLK | POWERPC_FLAG_HID0_LE;
 }
 
 static void init_proc_602(CPUPPCState *env)