target/ppc: Work [S]PURR implementation and add HV support

The Processor Utilisation of Resources Register (PURR) and Scaled
Processor Utilisation of Resources Register (SPURR) provide an estimate
of the resources used by the thread, present on POWER7 and later
processors.

Currently the [S]PURR registers simply count at the rate of the
timebase.

Preserve this behaviour but rework the implementation to store an offset
like the timebase rather than doing the calculation manually. Also allow
hypervisor write access to the register along with the currently
available read access.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
[ clg: rebased on current ppc tree ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20191128134700.16091-3-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

4 files changed, 22 insertions, 8 deletions

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index eb7d2c7..da44cc8 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -1311,6 +1311,7 @@ void cpu_ppc_store_decr(CPUPPCState *env, target_ulong value);
 target_ulong cpu_ppc_load_hdecr(CPUPPCState *env);
 void cpu_ppc_store_hdecr(CPUPPCState *env, target_ulong value);
 uint64_t cpu_ppc_load_purr(CPUPPCState *env);
+void cpu_ppc_store_purr(CPUPPCState *env, uint64_t value);
 uint32_t cpu_ppc601_load_rtcl(CPUPPCState *env);
 uint32_t cpu_ppc601_load_rtcu(CPUPPCState *env);
 #if !defined(CONFIG_USER_ONLY)
diff --git a/target/ppc/helper.h b/target/ppc/helper.h
index a5f53bb..356a14d 100644
--- a/target/ppc/helper.h
+++ b/target/ppc/helper.h
@@ -655,6 +655,7 @@ DEF_HELPER_FLAGS_1(load_601_rtcu, TCG_CALL_NO_RWG, tl, env)
 #if !defined(CONFIG_USER_ONLY)
 #if defined(TARGET_PPC64)
 DEF_HELPER_FLAGS_1(load_purr, TCG_CALL_NO_RWG, tl, env)
+DEF_HELPER_FLAGS_2(store_purr, TCG_CALL_NO_RWG, void, env, tl)
 DEF_HELPER_2(store_ptcr, void, env, tl)
 #endif
 DEF_HELPER_2(store_sdr1, void, env, tl)
diff --git a/target/ppc/timebase_helper.c b/target/ppc/timebase_helper.c
index 8c3c2fe..2395295 100644
--- a/target/ppc/timebase_helper.c
+++ b/target/ppc/timebase_helper.c
@@ -55,6 +55,11 @@ target_ulong helper_load_purr(CPUPPCState *env)
 {
     return (target_ulong)cpu_ppc_load_purr(env);
 }
+
+void helper_store_purr(CPUPPCState *env, target_ulong val)
+{
+    cpu_ppc_store_purr(env, val);
+}
 #endif
 
 target_ulong helper_load_601_rtcl(CPUPPCState *env)
diff --git a/target/ppc/translate_init.inc.c b/target/ppc/translate_init.inc.c
index 226aecf..c5e4d45 100644
--- a/target/ppc/translate_init.inc.c
+++ b/target/ppc/translate_init.inc.c
@@ -287,6 +287,11 @@ static void spr_read_purr(DisasContext *ctx, int gprn, int sprn)
     gen_helper_load_purr(cpu_gpr[gprn], cpu_env);
 }
 
+static void spr_write_purr(DisasContext *ctx, int sprn, int gprn)
+{
+    gen_helper_store_purr(cpu_env, cpu_gpr[gprn]);
+}
+
 /* HDECR */
 static void spr_read_hdecr(DisasContext *ctx, int gprn, int sprn)
 {
@@ -8013,14 +8018,16 @@ static void gen_spr_book3s_purr(CPUPPCState *env)
 {
 #if !defined(CONFIG_USER_ONLY)
     /* PURR & SPURR: Hack - treat these as aliases for the TB for now */
-    spr_register_kvm(env, SPR_PURR,   "PURR",
-                     &spr_read_purr, SPR_NOACCESS,
-                     &spr_read_purr, SPR_NOACCESS,
-                     KVM_REG_PPC_PURR, 0x00000000);
-    spr_register_kvm(env, SPR_SPURR,   "SPURR",
-                     &spr_read_purr, SPR_NOACCESS,
-                     &spr_read_purr, SPR_NOACCESS,
-                     KVM_REG_PPC_SPURR, 0x00000000);
+    spr_register_kvm_hv(env, SPR_PURR,   "PURR",
+                        &spr_read_purr, SPR_NOACCESS,
+                        &spr_read_purr, SPR_NOACCESS,
+                        &spr_read_purr, &spr_write_purr,
+                        KVM_REG_PPC_PURR, 0x00000000);
+    spr_register_kvm_hv(env, SPR_SPURR,   "SPURR",
+                        &spr_read_purr, SPR_NOACCESS,
+                        &spr_read_purr, SPR_NOACCESS,
+                        &spr_read_purr, &spr_write_purr,
+                        KVM_REG_PPC_SPURR, 0x00000000);
 #endif
 }