target/hppa: Implement Fast TLB Insert instructions

These instructions are present on pcxl and pcxl2 machines,
and are used by NetBSD and OpenBSD.  See

     https://parisc.wiki.kernel.org/images-parisc/a/a9/Pcxl2_ers.pdf
     page 13-9 (195/206)

Signed-off-by: Nick Hudson <skrll@netbsd.org>
Message-Id: <20190423063621.8203-2-nick.hudson@gmx.co.uk>
[rth: Use extending loads, locally managed temporaries.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

target/hppa/insns.decode

@@ -133,6 +133,9 @@ ixtlbx          000001 b:5 r:5 sp:2 0100000 addr:1 0 00000      data=1
 ixtlbx          000001 b:5 r:5 ... 000000 addr:1 0 00000        \
                 sp=%assemble_sr3x data=0
 
+# pcxl and pcxl2 Fast TLB Insert instructions
+ixtlbxf         000001 00000 r:5 00 0 data:1 01000 addr:1 0 00000
+
 pxtlbx          000001 b:5 x:5 sp:2 0100100 local:1 m:1 -----   data=1
 pxtlbx          000001 b:5 x:5 ... 000100 local:1 m:1 -----     \
                 sp=%assemble_sr3x data=0

target/hppa/translate.c

@@ -2518,6 +2518,60 @@ static bool trans_pxtlbx(DisasContext *ctx, arg_pxtlbx *a)
 #endif
 }
 
+/*
+ * Implement the pcxl and pcxl2 Fast TLB Insert instructions.
+ * See
+ *     https://parisc.wiki.kernel.org/images-parisc/a/a9/Pcxl2_ers.pdf
+ *     page 13-9 (195/206)
+ */
+static bool trans_ixtlbxf(DisasContext *ctx, arg_ixtlbxf *a)
+{
+    CHECK_MOST_PRIVILEGED(EXCP_PRIV_OPR);
+#ifndef CONFIG_USER_ONLY
+    TCGv_tl addr, atl, stl;
+    TCGv_reg reg;
+
+    nullify_over(ctx);
+
+    /*
+     * FIXME:
+     *  if (not (pcxl or pcxl2))
+     *    return gen_illegal(ctx);
+     *
+     * Note for future: these are 32-bit systems; no hppa64.
+     */
+
+    atl = tcg_temp_new_tl();
+    stl = tcg_temp_new_tl();
+    addr = tcg_temp_new_tl();
+
+    tcg_gen_ld32u_i64(stl, cpu_env,
+                      a->data ? offsetof(CPUHPPAState, cr[CR_ISR])
+                      : offsetof(CPUHPPAState, cr[CR_IIASQ]));
+    tcg_gen_ld32u_i64(atl, cpu_env,
+                      a->data ? offsetof(CPUHPPAState, cr[CR_IOR])
+                      : offsetof(CPUHPPAState, cr[CR_IIAOQ]));
+    tcg_gen_shli_i64(stl, stl, 32);
+    tcg_gen_or_tl(addr, atl, stl);
+    tcg_temp_free_tl(atl);
+    tcg_temp_free_tl(stl);
+
+    reg = load_gpr(ctx, a->r);
+    if (a->addr) {
+        gen_helper_itlba(cpu_env, addr, reg);
+    } else {
+        gen_helper_itlbp(cpu_env, addr, reg);
+    }
+    tcg_temp_free_tl(addr);
+
+    /* Exit TB for TLB change if mmu is enabled.  */
+    if (ctx->tb_flags & PSW_C) {
+        ctx->base.is_jmp = DISAS_IAQ_N_STALE;
+    }
+    return nullify_end(ctx);
+#endif
+}
+
 static bool trans_lpa(DisasContext *ctx, arg_ldst *a)
 {
     CHECK_MOST_PRIVILEGED(EXCP_PRIV_OPR);