PPR32 provides access to the upper half of PPR.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
v3:
- Don't clobber lower half of PPR.
- Add spr_load_dump_spr (spr_store_dump_spr was already there).

 target/ppc/cpu.h        |  1 +
 target/ppc/spr_common.h |  2 ++
 target/ppc/cpu_init.c   | 12 ++++++++++++
 target/ppc/translate.c  | 24 ++++++++++++++++++++++++
 4 files changed, 39 insertions(+)

diff --git a/target/ppc/cpu.h b/target/ppc/cpu.h
index 2532408be0..141cbefb4c 100644
--- a/target/ppc/cpu.h
+++ b/target/ppc/cpu.h
@@ -2120,6 +2120,7 @@ void ppc_compat_add_property(Object *obj, const char *name,
 #define SPR_POWER_MMCRS       (0x37E)
 #define SPR_WORT              (0x37F)
 #define SPR_PPR               (0x380)
+#define SPR_PPR32             (0x382)
 #define SPR_750_GQR0          (0x390)
 #define SPR_440_DNV0          (0x390)
 #define SPR_750_GQR1          (0x391)
diff --git a/target/ppc/spr_common.h b/target/ppc/spr_common.h
index eb2561f593..9e40b3b608 100644
--- a/target/ppc/spr_common.h
+++ b/target/ppc/spr_common.h
@@ -203,6 +203,8 @@ 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);
+void spr_read_ppr32(DisasContext *ctx, int sprn, int gprn);
+void spr_write_ppr32(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 892fb6ce02..7684a59d75 100644
--- a/target/ppc/cpu_init.c
+++ b/target/ppc/cpu_init.c
@@ -5623,6 +5623,14 @@ static void register_HEIR64_spr(CPUPPCState *env)
                  0x00000000);
 }
 
+static void register_power7_common_sprs(CPUPPCState *env)
+{
+    spr_register(env, SPR_PPR32, "PPR32",
+                 &spr_read_ppr32, &spr_write_ppr32,
+                 &spr_read_ppr32, &spr_write_ppr32,
+                 0x00000000);
+}
+
 static void register_power8_tce_address_control_sprs(CPUPPCState *env)
 {
     spr_register_kvm(env, SPR_TAR, "TAR",
@@ -6118,6 +6126,7 @@ static void init_proc_POWER7(CPUPPCState *env)
     register_power6_common_sprs(env);
     register_HEIR32_spr(env);
     register_power6_dbg_sprs(env);
+    register_power7_common_sprs(env);
     register_power7_book4_sprs(env);
 
     /* env variables */
@@ -6264,6 +6273,7 @@ static void init_proc_POWER8(CPUPPCState *env)
     register_power6_common_sprs(env);
     register_HEIR32_spr(env);
     register_power6_dbg_sprs(env);
+    register_power7_common_sprs(env);
     register_power8_tce_address_control_sprs(env);
     register_power8_ids_sprs(env);
     register_power8_ebb_sprs(env);
@@ -6431,6 +6441,7 @@ static void init_proc_POWER9(CPUPPCState *env)
     register_power6_common_sprs(env);
     register_HEIR32_spr(env);
     register_power6_dbg_sprs(env);
+    register_power7_common_sprs(env);
     register_power8_tce_address_control_sprs(env);
     register_power8_ids_sprs(env);
     register_power8_ebb_sprs(env);
@@ -6625,6 +6636,7 @@ static void init_proc_POWER10(CPUPPCState *env)
     register_power6_common_sprs(env);
     register_HEIR64_spr(env);
     register_power6_dbg_sprs(env);
+    register_power7_common_sprs(env);
     register_power8_tce_address_control_sprs(env);
     register_power8_ids_sprs(env);
     register_power8_ebb_sprs(env);
diff --git a/target/ppc/translate.c b/target/ppc/translate.c
index 120858a188..44212192be 100644
--- a/target/ppc/translate.c
+++ b/target/ppc/translate.c
@@ -1411,6 +1411,30 @@ void spr_read_dexcr_ureg(DisasContext *ctx, int gprn, int sprn)
     gen_load_spr(t0, sprn + 16);
     tcg_gen_ext32u_tl(cpu_gpr[gprn], t0);
 }
+
+/* The PPR32 SPR accesses the upper 32-bits of PPR */
+void spr_read_ppr32(DisasContext *ctx, int gprn, int sprn)
+{
+    gen_load_spr(cpu_gpr[gprn], SPR_PPR);
+    tcg_gen_shri_tl(cpu_gpr[gprn], cpu_gpr[gprn], 32);
+    spr_load_dump_spr(SPR_PPR);
+}
+
+void spr_write_ppr32(DisasContext *ctx, int sprn, int gprn)
+{
+    TCGv t0 = tcg_temp_new();
+
+    /*
+     * Don't clobber the low 32-bits of the PPR. These are all reserved bits
+     * but TCG does implement them, so it would be surprising to zero them
+     * here. "Priority nops" are similarly careful not to clobber reserved
+     * bits.
+     */
+    gen_load_spr(t0, SPR_PPR);
+    tcg_gen_deposit_tl(t0, t0, cpu_gpr[gprn], 32, 32);
+    gen_store_spr(SPR_PPR, t0);
+    spr_store_dump_spr(SPR_PPR);
+}
 #endif
 
 #define GEN_HANDLER(name, opc1, opc2, opc3, inval, type)                      \
-- 
2.43.0

On 5/21/24 20:41, Nicholas Piggin wrote:
> PPR32 provides access to the upper half of PPR.
> 
> Signed-off-by: Nicholas Piggin<npiggin@gmail.com>
> ---
> v3:
> - Don't clobber lower half of PPR.
> - Add spr_load_dump_spr (spr_store_dump_spr was already there).
> 
>   target/ppc/cpu.h        |  1 +
>   target/ppc/spr_common.h |  2 ++
>   target/ppc/cpu_init.c   | 12 ++++++++++++
>   target/ppc/translate.c  | 24 ++++++++++++++++++++++++
>   4 files changed, 39 insertions(+)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

r~