[PATCH 25/26] target/ppc: Implement SPRC/SPRD SPRs

[Nicholas Piggin]

This implements SPRC/SPRD SPRs, and SCRATCH0-7 registers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 target/ppc/cpu.h         |  7 +++--
 target/ppc/helper.h      |  3 ++
 target/ppc/spr_common.h  |  3 ++
 target/ppc/cpu_init.c    | 10 ++++++
 target/ppc/misc_helper.c | 66 ++++++++++++++++++++++++++++++++++++++++
 target/ppc/translate.c   | 18 +++++++++++
 6 files changed, 105 insertions(+), 2 deletions(-)

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index b6a955b9b7..a50440ea51 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1266,6 +1266,9 @@ struct CPUArchState {
     ppc_slb_t slb[MAX_SLB_ENTRIES]; /* PowerPC 64 SLB area */
     struct CPUBreakpoint *ciabr_breakpoint;
     struct CPUWatchpoint *dawr0_watchpoint;
+
+    /* POWER CPU regs/state */
+    target_ulong scratch[8]; /* SCRATCH registers (shared across core) */
 #endif
     target_ulong sr[32];   /* segment registers */
     uint32_t nb_BATs;      /* number of BATs */
@@ -1802,9 +1805,9 @@ void ppc_compat_add_property(Object *obj, const char 
*name,
 #define SPR_SPRG2             (0x112)
 #define SPR_SPRG3             (0x113)
 #define SPR_SPRG4             (0x114)
-#define SPR_SCOMC             (0x114)
+#define SPR_POWER_SPRC        (0x114)
 #define SPR_SPRG5             (0x115)
-#define SPR_SCOMD             (0x115)
+#define SPR_POWER_SPRD        (0x115)
 #define SPR_SPRG6             (0x116)
 #define SPR_SPRG7             (0x117)
 #define SPR_ASR               (0x118)
diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index 8cdb322ed6..43333b4d5e 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -730,6 +730,9 @@ DEF_HELPER_2(book3s_msgsndp, void, env, tl)
 DEF_HELPER_2(book3s_msgclrp, void, env, tl)
 DEF_HELPER_1(load_tfmr, tl, env)
 DEF_HELPER_2(store_tfmr, void, env, tl)
+DEF_HELPER_FLAGS_2(store_sprc, TCG_CALL_NO_RWG, void, env, tl)
+DEF_HELPER_FLAGS_1(load_sprd, TCG_CALL_NO_RWG_SE, tl, env)
+DEF_HELPER_FLAGS_2(store_sprd, TCG_CALL_NO_RWG, void, env, tl)
 #endif
 DEF_HELPER_2(store_sdr1, void, env, tl)
 DEF_HELPER_2(store_pidr, void, env, tl)
diff --git a/target/ppc/spr_common.h b/target/ppc/spr_common.h
index 85f73b860b..01aff449bc 100644
--- a/target/ppc/spr_common.h
+++ b/target/ppc/spr_common.h
@@ -207,6 +207,9 @@ void spr_write_lpcr(DisasContext *ctx, int sprn, int gprn);
 void spr_read_dexcr_ureg(DisasContext *ctx, int gprn, int sprn);
 void spr_read_ppr32(DisasContext *ctx, int sprn, int gprn);
 void spr_write_ppr32(DisasContext *ctx, int sprn, int gprn);
+void spr_write_sprc(DisasContext *ctx, int sprn, int gprn);
+void spr_read_sprd(DisasContext *ctx, int sprn, int gprn);
+void spr_write_sprd(DisasContext *ctx, int sprn, int gprn);
 #endif
 
 void register_low_BATs(CPUPPCState *env);
diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index 31d535d501..d42996bbb0 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -5705,6 +5705,16 @@ static void register_power_common_book4_sprs(CPUPPCState 
*env)
                  SPR_NOACCESS, SPR_NOACCESS,
                  &spr_read_generic, &spr_core_write_generic,
                  0x00000000);
+    spr_register_hv(env, SPR_POWER_SPRC, "SPRC",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_generic, &spr_write_sprc,
+                 0x00000000);
+    spr_register_hv(env, SPR_POWER_SPRD, "SPRD",
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 SPR_NOACCESS, SPR_NOACCESS,
+                 &spr_read_sprd, &spr_write_sprd,
+                 0x00000000);
 #endif
 }
 
diff --git a/target/ppc/misc_helper.c b/target/ppc/misc_helper.c
index 5317713fc3..68620f19cd 100644
--- a/target/ppc/misc_helper.c
+++ b/target/ppc/misc_helper.c
@@ -310,6 +310,72 @@ void helper_store_dpdes(CPUPPCState *env, target_ulong val)
     }
     bql_unlock();
 }
+
+/* Indirect SCOM (SPRC/SPRD) access to SCRATCH0-7 are implemented. */
+void helper_store_sprc(CPUPPCState *env, target_ulong val)
+{
+    if (val & ~0x3f8ULL) {
+        qemu_log_mask(LOG_GUEST_ERROR, "Invalid SPRC register value "
+                      TARGET_FMT_lx"\n", val);
+        return;
+    }
+    env->spr[SPR_POWER_SPRC] = val;
+}
+
+target_ulong helper_load_sprd(CPUPPCState *env)
+{
+    target_ulong sprc = env->spr[SPR_POWER_SPRC];
+
+    switch (sprc & 0x3c0) {
+    case 0: /* SCRATCH0-7 */
+        return env->scratch[(sprc >> 3) & 0x7];
+    default:
+        qemu_log_mask(LOG_UNIMP, "mfSPRD: Unimplemented SPRC:0x"
+                                  TARGET_FMT_lx"\n", sprc);
+        break;
+    }
+    return 0;
+}
+
+static void do_store_scratch(CPUPPCState *env, int nr, target_ulong val)
+{
+    CPUState *cs = env_cpu(env);
+    CPUState *ccs;
+    uint32_t nr_threads = cs->nr_threads;
+
+    /*
+     * Log stores to SCRATCH, because some firmware uses these for debugging
+     * and logging, but they would normally be read by the BMC, which is
+     * not implemented in QEMU yet. This gives a way to get at the information.
+     * Could also dump these upon checkstop.
+     */
+    qemu_log("SPRD write 0x%016lx to SCRATCH%d\n", val, nr);
+
+    if (nr_threads == 1) {
+        env->scratch[nr] = val;
+        return;
+    }
+
+    THREAD_SIBLING_FOREACH(cs, ccs) {
+        CPUPPCState *cenv = &POWERPC_CPU(ccs)->env;
+        cenv->scratch[nr] = val;
+    }
+}
+
+void helper_store_sprd(CPUPPCState *env, target_ulong val)
+{
+    target_ulong sprc = env->spr[SPR_POWER_SPRC];
+
+    switch (sprc & 0x3c0) {
+    case 0: /* SCRATCH0-7 */
+        do_store_scratch(env, (sprc >> 3) & 0x7, val);
+        break;
+    default:
+        qemu_log_mask(LOG_UNIMP, "mfSPRD: Unimplemented SPRC:0x"
+                                  TARGET_FMT_lx"\n", sprc);
+        break;
+    }
+}
 #endif /* defined(TARGET_PPC64) */
 
 void helper_store_pidr(CPUPPCState *env, target_ulong val)
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 41aeb2d06e..bdd39c89e0 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -1298,6 +1298,24 @@ void spr_write_tfmr(DisasContext *ctx, int sprn, int 
gprn)
     gen_helper_store_tfmr(tcg_env, cpu_gpr[gprn]);
 }
 
+void spr_write_sprc(DisasContext *ctx, int sprn, int gprn)
+{
+    gen_helper_store_sprc(tcg_env, cpu_gpr[gprn]);
+}
+
+void spr_read_sprd(DisasContext *ctx, int gprn, int sprn)
+{
+    gen_helper_load_sprd(cpu_gpr[gprn], tcg_env);
+}
+
+void spr_write_sprd(DisasContext *ctx, int sprn, int gprn)
+{
+    if (!gen_serialize_core(ctx)) {
+        return;
+    }
+    gen_helper_store_sprd(tcg_env, cpu_gpr[gprn]);
+}
+
 void spr_write_lpcr(DisasContext *ctx, int sprn, int gprn)
 {
     translator_io_start(&ctx->base);
-- 
2.42.0