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ppc: Improve emulation of THRM registers

PATCH In review Benjamin Herrenschmidt 3 participants 3 messages Jun 19, 2016 – Jun 20, 2016

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Benjamin Herrenschmidt

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#0 lore raw

PATCH 1/1 ppc: Improve emulation of THRM registers

The 75x and 74xx processors have some thermal monitoring SPRs that some OSes such as MacOS do use. Our current "dumb" implementation isn't good enough and will cause some versions of MacOS to hang during boot.

This lifts an improved emulation from MacOnLinux and adapts it to qemu, thus fixing the problem.

Signed-off-by Benjamin Herrenschmidt <[email protected]>
---
 target-ppc/helper.h         |  1 +
 target-ppc/misc_helper.c    | 41 +++++++++++++++++++++++++++++++++++++++++
 target-ppc/translate_init.c | 13 ++++++++++---
 3 files changed, 52 insertions(+), 3 deletions(-)
target-ppc/helper.h +1 -0
index f4410a8..18eb52f 100644
@@ -670,3 +670,4 @@ DEF_HELPER_4(dscli, void, env, fprp, fprp, i32)
 DEF_HELPER_4(dscliq, void, env, fprp, fprp, i32)
 
 DEF_HELPER_1(tbegin, void, env)
+DEF_HELPER_1(fixup_thrm, void, env)
target-ppc/misc_helper.c +41 -0

44 lines not on this page · raw message

target-ppc/translate_init.c +10 -3
index ca894ff..0f18abf 100644
@@ -1179,23 +1179,30 @@ static void gen_spr_amr(CPUPPCState *env, bool has_iamr)
 }
 #endif /* TARGET_PPC64 */
 
+static void spr_read_thrm(DisasContext *ctx, int gprn, int sprn)
+{
+    gen_helper_fixup_thrm(cpu_env);
+    gen_load_spr(cpu_gpr[gprn], sprn);
+    spr_load_dump_spr(sprn);
+}
+
 static void gen_spr_thrm (CPUPPCState *env)
 {
     /* Thermal management */
     /* XXX : not implemented */
     spr_register(env, SPR_THRM1, "THRM1",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_thrm, &spr_write_generic,
                  0x00000000);
     /* XXX : not implemented */
     spr_register(env, SPR_THRM2, "THRM2",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_thrm, &spr_write_generic,
                  0x00000000);
     /* XXX : not implemented */
     spr_register(env, SPR_THRM3, "THRM3",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_thrm, &spr_write_generic,
                  0x00000000);
 }
#1 lore raw
Quoted 29 lines · Benjamin Herrenschmidt

The 75x and 74xx processors have some thermal monitoring SPRs that some OSes such as MacOS do use. Our current "dumb" implementation isn't good enough and will cause some versions of MacOS to hang during boot.

This lifts an improved emulation from MacOnLinux and adapts it to qemu, thus fixing the problem.

Signed-off-by Benjamin Herrenschmidt <[email protected]>

---

target-ppc/helper.h         |  1 +
target-ppc/misc_helper.c    | 41 +++++++++++++++++++++++++++++++++++++++++
target-ppc/translate_init.c | 13 ++++++++++---
3 files changed, 52 insertions(+), 3 deletions(-)
target-ppc/helper.h +1 -0
index f4410a8..18eb52f 100644
@@ -670,3 +670,4 @@ DEF_HELPER_4(dscli, void, env, fprp, fprp, i32)
 DEF_HELPER_4(dscliq, void, env, fprp, fprp, i32)
 
 DEF_HELPER_1(tbegin, void, env)
+DEF_HELPER_1(fixup_thrm, void, env)
target-ppc/misc_helper.c +0 -0
index 7d41b01..4315778 100644

target-ppc/misc_helper.c void ppc_store_msr(CPUPPCState *env, target_ulong value) · line 172

Quoted 7 lines
target-ppc/misc_helper.c +4 -0
@@ -166,3 +166,44 @@ void ppc_store_msr(CPUPPCState *env, target_ulong value)
 {
    hreg_store_msr(env, value, 0);
 }
+
+/* This code is lifted from MacOnLinux. It is called whenever
+ * THRM1,2 or 3 is read an fixes up the values in such a way
+ * that will mac MacOS not hang. These registers exist on some

Typo: mac -> make?

#2 lore raw
Quoted 23 lines · BALATON Zoltan
Quoted 22 lines · Benjamin Herrenschmidt

The 75x and 74xx processors have some thermal monitoring SPRs that some OSes such as MacOS do use. Our current "dumb" implementation isn't good enough and will cause some versions of MacOS to hang during boot.

This lifts an improved emulation from MacOnLinux and adapts it to qemu, thus fixing the problem.

Signed-off-by Benjamin Herrenschmidt <[email protected]>

---

target-ppc/helper.h         |  1 +
target-ppc/misc_helper.c    | 41 +++++++++++++++++++++++++++++++++++++++++
target-ppc/translate_init.c | 13 ++++++++++---
3 files changed, 52 insertions(+), 3 deletions(-)
target-ppc/helper.h +0 -0
index f4410a8..18eb52f 100644
@@ -670,3 +670,4 @@ DEF_HELPER_4(dscli, void, env, fprp, fprp, i32)
 DEF_HELPER_4(dscliq, void, env, fprp, fprp, i32)
Quoted 16 lines
Quoted 7 lines
target-ppc/helper.h +1 -0
 DEF_HELPER_1(tbegin, void, env)
+DEF_HELPER_1(fixup_thrm, void, env)
target-ppc/misc_helper.c +0 -0
index 7d41b01..4315778 100644

target-ppc/misc_helper.c void ppc_store_msr(CPUPPCState *env, target_ulong value) · line 172

Quoted 7 lines
target-ppc/misc_helper.c +4 -0
@@ -166,3 +166,44 @@ void ppc_store_msr(CPUPPCState *env, target_ulong value)
 {
    hreg_store_msr(env, value, 0);
 }
+
+/* This code is lifted from MacOnLinux. It is called whenever
+ * THRM1,2 or 3 is read an fixes up the values in such a way
+ * that will mac MacOS not hang. These registers exist on some

Typo: mac -> make?

I've made this change, along with a number of checkpatch fixes as I've merged this into my tree.

Signature · 4 lines
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david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
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