[PATCH 2/4] target/hppa: Add instruction decoding for mfdiag and mtdiag

[deller@kernel.org]

From: Helge Deller <deller@gmx.de>

Add 32- and 64-bit instruction decoding of the mfdiag and mtdiag
instructions which modify the diagnose registers.

diag_getshadowregs_pa2() and diag_putshadowregs_pa2() were added in
commit 3bdf20819e68 based on some analysis of ODE code, but now they
conflict with the generic mfdiag/mtdiag instructions. I believe the
former analysis was wrong, so remove them again. Note that all diag
instructions are badly documented, so most things are based on reverse
engineering and thus may be wrong.

Signed-off-by: Helge Deller <deller@gmx.de>
Fixes: 3bdf20819e68 ("target/hppa: Add diag instructions to set/restore shadow registers")
---
 target/hppa/insns.decode |  6 ++++--
 target/hppa/translate.c  | 22 ++++++++++++++++------
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/target/hppa/insns.decode b/target/hppa/insns.decode
index 71074a64c1..4eaac750ea 100644
--- a/target/hppa/insns.decode
+++ b/target/hppa/insns.decode
@@ -644,10 +644,12 @@ xmpyu           001110 ..... ..... 010 .0111 .00 t:5    r1=%ra64 r2=%rb64
     # For 32-bit PA-7300LC (PCX-L2)
     diag_getshadowregs_pa1  000101 00 0000 0000 0001 1010 0000 0000
     diag_putshadowregs_pa1  000101 00 0000 0000 0001 1010 0100 0000
+    diag_mfdiag             000101 dr:5  rt:5   0000 0110 0000 0000
+    diag_mtdiag             000101 dr:5  r1:5   0001 0110 0000 0000
 
     # For 64-bit PA8700 (PCX-W2)
-    diag_getshadowregs_pa2  000101 00 0111 1000 0001 1000 0100 0000
-    diag_putshadowregs_pa2  000101 00 0111 0000 0001 1000 0100 0000
+    diag_mfdiag             000101 dr:5  0 0000 0000 1000 101  rt:5
+    diag_mtdiag             000101 dr:5  r1:5   0001 1000 0100 0000
   ]
   diag_unimp                000101 i:26
 }
diff --git a/target/hppa/translate.c b/target/hppa/translate.c
index dc04f9f3c0..7b9d3deb39 100644
--- a/target/hppa/translate.c
+++ b/target/hppa/translate.c
@@ -4593,19 +4593,29 @@ static bool trans_diag_getshadowregs_pa1(DisasContext *ctx, arg_empty *a)
     return !ctx->is_pa20 && do_getshadowregs(ctx);
 }
 
-static bool trans_diag_getshadowregs_pa2(DisasContext *ctx, arg_empty *a)
+static bool trans_diag_putshadowregs_pa1(DisasContext *ctx, arg_empty *a)
 {
-    return ctx->is_pa20 && do_getshadowregs(ctx);
+    return !ctx->is_pa20 && do_putshadowregs(ctx);
 }
 
-static bool trans_diag_putshadowregs_pa1(DisasContext *ctx, arg_empty *a)
+static bool trans_diag_mfdiag(DisasContext *ctx, arg_diag_mfdiag *a)
 {
-    return !ctx->is_pa20 && do_putshadowregs(ctx);
+    CHECK_MOST_PRIVILEGED(EXCP_PRIV_OPR);
+    nullify_over(ctx);
+    TCGv_i64 dest = dest_gpr(ctx, a->rt);
+    tcg_gen_ld_i64(dest, tcg_env,
+                       offsetof(CPUHPPAState, dr[a->dr]));
+    save_gpr(ctx, a->rt, dest);
+    return nullify_end(ctx);
 }
 
-static bool trans_diag_putshadowregs_pa2(DisasContext *ctx, arg_empty *a)
+static bool trans_diag_mtdiag(DisasContext *ctx, arg_diag_mtdiag *a)
 {
-    return ctx->is_pa20 && do_putshadowregs(ctx);
+    CHECK_MOST_PRIVILEGED(EXCP_PRIV_OPR);
+    nullify_over(ctx);
+    tcg_gen_st_i64(load_gpr(ctx, a->r1), tcg_env,
+                        offsetof(CPUHPPAState, dr[a->dr]));
+    return nullify_end(ctx);
 }
 
 static bool trans_diag_unimp(DisasContext *ctx, arg_diag_unimp *a)
-- 
2.47.0