target/mips: Fix Loongson-3A4000 MSAIR config register

When using the Loongson-3A4000 CPU, the MSAIR is returned with a
zero value (because unimplemented). Checking on real hardware,
this value appears incorrect:

  $ cat /proc/cpuinfo
  system type     : generic-loongson-machine
  machine         : loongson,generic
  cpu model       : Loongson-3 V0.4  FPU V0.1
  model name      : Loongson-3A R4 (Loongson-3A4000) @ 1800MHz
  isa             : mips1 mips2 mips3 mips4 mips5 mips32r1 mips32r2 mips64r1 mips64r2
  ASEs implemented        : vz msa loongson-mmi loongson-cam loongson-ext loongson-ext2
  ...

Checking the CFCMSA opcode result with gdb we get 0x60140:

  Breakpoint 1, 0x00000001200037c4 in main ()
  1: x/i $pc
  => 0x1200037c4 <main+52>:  cfcmsa       v0,msa_ir
  (gdb) si
  0x00000001200037c8 in main ()
  (gdb) i r v0
  v0: 0x60140

MSAIR bits 17 and 18 are "reserved" per the spec revision 1.12,
so mask them out, and set MSAIR=0x0140 for the Loongson-3A4000
CPU model added in commit af868995e1b.

Cc: Huacai Chen <chenhuacai@kernel.org>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20211026180920.1085516-1-f4bug@amsat.org>

diff --git a/target/mips/cpu-defs.c.inc b/target/mips/cpu-defs.c.inc
index cbc45fc..ee8b322 100644 (file)
--- a/target/mips/cpu-defs.c.inc
+++ b/target/mips/cpu-defs.c.inc
@@ -886,6 +886,7 @@ const mips_def_t mips_defs[] =
                     (0x1 << FCR0_D) | (0x1 << FCR0_S),
         .CP1_fcr31 = 0,
         .CP1_fcr31_rw_bitmask = 0xFF83FFFF,
+        .MSAIR = (0x01 << MSAIR_ProcID) | (0x40 << MSAIR_Rev),
         .SEGBITS = 48,
         .PABITS = 48,
         .insn_flags = CPU_MIPS64R2 | INSN_LOONGSON3A |