[PATCH 2/2] target/ppc: Add TFMR SPR implementation with read and write helpers

[Nicholas Piggin <npiggin@gmail.com>]

TFMR is the Time Facility Management Register which is specific to
POWER CPUs, and used for the purpose of timebase management (generally
by firmware, not the OS).

Add helpers for the TFMR register, which will form part of the core
timebase facility model in future but for now behaviour is unchanged.

Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 target/ppc/cpu_init.c        |  2 +-
 target/ppc/helper.h          |  2 ++
 target/ppc/spr_common.h      |  2 ++
 target/ppc/timebase_helper.c | 13 +++++++++++++
 target/ppc/translate.c       | 10 ++++++++++
 5 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/target/ppc/cpu_init.c b/target/ppc/cpu_init.c
index 21ff4861c3..7d1b148fd4 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -5658,7 +5658,7 @@ static void register_power_common_book4_sprs(CPUPPCState *env)
     spr_register_hv(env, SPR_TFMR, "TFMR",
                  SPR_NOACCESS, SPR_NOACCESS,
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_tfmr, &spr_write_tfmr,
                  0x00000000);
 #endif
 }
diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index fda40b8a60..eac5e7ab5d 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -745,6 +745,8 @@ DEF_HELPER_2(store_40x_dbcr0, void, env, tl)
 DEF_HELPER_2(store_40x_sler, void, env, tl)
 DEF_HELPER_FLAGS_2(store_booke_tcr, TCG_CALL_NO_RWG, void, env, tl)
 DEF_HELPER_FLAGS_2(store_booke_tsr, TCG_CALL_NO_RWG, void, env, tl)
+DEF_HELPER_1(load_tfmr, tl, env)
+DEF_HELPER_2(store_tfmr, void, env, tl)
 DEF_HELPER_3(store_ibatl, void, env, i32, tl)
 DEF_HELPER_3(store_ibatu, void, env, i32, tl)
 DEF_HELPER_3(store_dbatl, void, env, i32, tl)
diff --git a/target/ppc/spr_common.h b/target/ppc/spr_common.h
index 4c0f2bed77..fbf52123b5 100644
--- a/target/ppc/spr_common.h
+++ b/target/ppc/spr_common.h
@@ -194,6 +194,8 @@ void spr_write_ebb(DisasContext *ctx, int sprn, int gprn);
 void spr_read_ebb_upper32(DisasContext *ctx, int gprn, int sprn);
 void spr_write_ebb_upper32(DisasContext *ctx, int sprn, int gprn);
 void spr_write_hmer(DisasContext *ctx, int sprn, int gprn);
+void spr_read_tfmr(DisasContext *ctx, int gprn, int sprn);
+void spr_write_tfmr(DisasContext *ctx, int sprn, int gprn);
 void spr_write_lpcr(DisasContext *ctx, int sprn, int gprn);
 void spr_read_dexcr_ureg(DisasContext *ctx, int gprn, int sprn);
 #endif
diff --git a/target/ppc/timebase_helper.c b/target/ppc/timebase_helper.c
index b80f56af7e..08a6b47ee0 100644
--- a/target/ppc/timebase_helper.c
+++ b/target/ppc/timebase_helper.c
@@ -144,6 +144,19 @@ void helper_store_booke_tsr(CPUPPCState *env, target_ulong val)
     store_booke_tsr(env, val);
 }
 
+#if defined(TARGET_PPC64)
+/* POWER processor Timebase Facility */
+target_ulong helper_load_tfmr(CPUPPCState *env)
+{
+    return env->spr[SPR_TFMR];
+}
+
+void helper_store_tfmr(CPUPPCState *env, target_ulong val)
+{
+    env->spr[SPR_TFMR] = val;
+}
+#endif
+
 /*****************************************************************************/
 /* Embedded PowerPC specific helpers */
 
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index eb278c2683..9ce03344de 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -1175,6 +1175,16 @@ void spr_write_hmer(DisasContext *ctx, int sprn, int gprn)
     spr_store_dump_spr(sprn);
 }
 
+void spr_read_tfmr(DisasContext *ctx, int gprn, int sprn)
+{
+    gen_helper_load_tfmr(cpu_gpr[gprn], cpu_env);
+}
+
+void spr_write_tfmr(DisasContext *ctx, int sprn, int gprn)
+{
+    gen_helper_store_tfmr(cpu_env, cpu_gpr[gprn]);
+}
+
 void spr_write_lpcr(DisasContext *ctx, int sprn, int gprn)
 {
     gen_helper_store_lpcr(cpu_env, cpu_gpr[gprn]);
-- 
2.40.1