PPC: Ignore writes to L2CR

The L2CR register contains a number of bits that either impose configuration
which we can't deal with or mean "something is in progress until the bit is
0 again".

Since we don't model the former and we do want to accomodate guests using the
latter semantics, let's just ignore writes to L2CR. That way guests always read
back 0 and are usually happy with that.
Signed-off-by: NAlexander Graf <agraf@suse.de>

target-ppc/translate_init.c

@@ -1381,7 +1381,7 @@ static void gen_spr_74xx (CPUPPCState *env)
     /* XXX : not implemented */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* Not strictly an SPR */
     vscr_init(env, 0x00010000);
@@ -5169,7 +5169,7 @@ static void init_proc_750 (CPUPPCState *env)
     /* XXX : not implemented */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* Time base */
     gen_tbl(env);
@@ -5232,7 +5232,7 @@ static void init_proc_750cl (CPUPPCState *env)
     /* XXX : not implemented */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* Time base */
     gen_tbl(env);
@@ -5418,7 +5418,7 @@ static void init_proc_750cx (CPUPPCState *env)
     /* XXX : not implemented */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* Time base */
     gen_tbl(env);
@@ -5485,7 +5485,7 @@ static void init_proc_750fx (CPUPPCState *env)
     /* XXX : not implemented */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* Time base */
     gen_tbl(env);
@@ -5557,7 +5557,7 @@ static void init_proc_750gx (CPUPPCState *env)
     /* XXX : not implemented (XXX: different from 750fx) */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* Time base */
     gen_tbl(env);
@@ -5693,7 +5693,7 @@ static void init_proc_755 (CPUPPCState *env)
     /* XXX : not implemented */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* XXX : not implemented */
     spr_register(env, SPR_L2PMCR, "L2PMCR",
@@ -6524,7 +6524,7 @@ static void init_proc_970 (CPUPPCState *env)
     /* XXX : not implemented */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* Memory management */
     /* XXX: not correct */
@@ -6624,7 +6624,7 @@ static void init_proc_970FX (CPUPPCState *env)
     /* XXX : not implemented */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* Memory management */
     /* XXX: not correct */
@@ -6736,7 +6736,7 @@ static void init_proc_970GX (CPUPPCState *env)
     /* XXX : not implemented */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* Memory management */
     /* XXX: not correct */
@@ -6836,7 +6836,7 @@ static void init_proc_970MP (CPUPPCState *env)
     /* XXX : not implemented */
     spr_register(env, SPR_L2CR, "L2CR",
                  SPR_NOACCESS, SPR_NOACCESS,
-                 &spr_read_generic, &spr_write_generic,
+                 &spr_read_generic, NULL,
                  0x00000000);
     /* Memory management */
     /* XXX: not correct */