target/ppc: SMT support for the HID SPR

HID is a per-core shared register, skiboot sets this (e.g., setting
HILE) on one thread and that must affect all threads of the core.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Message-ID: <20230705120631.27670-3-npiggin@gmail.com>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>

target/ppc/cpu_init.c

@@ -5638,7 +5638,7 @@ static void register_power_common_book4_sprs(CPUPPCState *env)
     spr_register_hv(env, SPR_HID0, "HID0",
                  SPR_NOACCESS, SPR_NOACCESS,
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, &spr_core_write_generic,
                  0x00000000);
     spr_register_hv(env, SPR_TSCR, "TSCR",
                  SPR_NOACCESS, SPR_NOACCESS,

target/ppc/helper.h

@@ -704,6 +704,7 @@ DEF_HELPER_3(store_dcr, void, env, tl, tl)
 
 DEF_HELPER_2(load_dump_spr, void, env, i32)
 DEF_HELPER_2(store_dump_spr, void, env, i32)
+DEF_HELPER_3(spr_core_write_generic, void, env, i32, tl)
 DEF_HELPER_3(spr_write_CTRL, void, env, i32, tl)
 
 DEF_HELPER_4(fscr_facility_check, void, env, i32, i32, i32)

target/ppc/misc_helper.c

@@ -43,6 +43,27 @@ void helper_store_dump_spr(CPUPPCState *env, uint32_t sprn)
              env->spr[sprn]);
 }
 
+void helper_spr_core_write_generic(CPUPPCState *env, uint32_t sprn,
+                                   target_ulong val)
+{
+    CPUState *cs = env_cpu(env);
+    CPUState *ccs;
+    uint32_t nr_threads = cs->nr_threads;
+    uint32_t core_id = env->spr[SPR_PIR] & ~(nr_threads - 1);
+
+    assert(core_id == env->spr[SPR_PIR] - env->spr[SPR_TIR]);
+
+    if (nr_threads == 1) {
+        env->spr[sprn] = val;
+        return;
+    }
+
+    THREAD_SIBLING_FOREACH(cs, ccs) {
+        CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
+        cenv->spr[sprn] = val;
+    }
+}
+
 void helper_spr_write_CTRL(CPUPPCState *env, uint32_t sprn,
                            target_ulong val)
 {

target/ppc/spr_common.h

@@ -82,6 +82,7 @@ void spr_noaccess(DisasContext *ctx, int gprn, int sprn);
 void spr_read_generic(DisasContext *ctx, int gprn, int sprn);
 void spr_write_generic(DisasContext *ctx, int sprn, int gprn);
 void spr_write_generic32(DisasContext *ctx, int sprn, int gprn);
+void spr_core_write_generic(DisasContext *ctx, int sprn, int gprn);
 void spr_write_MMCR0(DisasContext *ctx, int sprn, int gprn);
 void spr_write_MMCR1(DisasContext *ctx, int sprn, int gprn);
 void spr_write_PMC(DisasContext *ctx, int sprn, int gprn);

target/ppc/translate.c

@@ -438,6 +438,22 @@ void spr_write_generic32(DisasContext *ctx, int sprn, int gprn)
 #endif
 }
 
+void spr_core_write_generic(DisasContext *ctx, int sprn, int gprn)
+{
+    if (!(ctx->flags & POWERPC_FLAG_SMT)) {
+        spr_write_generic(ctx, sprn, gprn);
+        return;
+    }
+
+    if (!gen_serialize(ctx)) {
+        return;
+    }
+
+    gen_helper_spr_core_write_generic(cpu_env, tcg_constant_i32(sprn),
+                                      cpu_gpr[gprn]);
+    spr_store_dump_spr(sprn);
+}
+
 static void spr_write_CTRL_ST(DisasContext *ctx, int sprn, int gprn)
 {
     /* This does not implement >1 thread */