linux-user: MIPS set cpu to r6 CPU if binary is R6

So here we need to detect the version of binaries and set
cpu_model for it.

Signed-off-by: YunQiang Su <syq@debian.org>
[lv: original patch modified to move code into cpu_get_model()]
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20180220173307.25125-5-laurent@vivier.eu>

include/elf.h

@@ -33,6 +33,9 @@ typedef int64_t  Elf64_Sxword;
 
 /* Flags in the e_flags field of the header */
 /* MIPS architecture level. */
+#define EF_MIPS_ARCH            0xf0000000
+
+/* Legal values for MIPS architecture level.  */
 #define EF_MIPS_ARCH_1		0x00000000	/* -mips1 code.  */
 #define EF_MIPS_ARCH_2		0x10000000	/* -mips2 code.  */
 #define EF_MIPS_ARCH_3		0x20000000	/* -mips3 code.  */
@@ -40,6 +43,10 @@ typedef int64_t  Elf64_Sxword;
 #define EF_MIPS_ARCH_5		0x40000000	/* -mips5 code.  */
 #define EF_MIPS_ARCH_32		0x50000000	/* MIPS32 code.  */
 #define EF_MIPS_ARCH_64		0x60000000	/* MIPS64 code.  */
+#define EF_MIPS_ARCH_32R2       0x70000000      /* MIPS32r2 code.  */
+#define EF_MIPS_ARCH_64R2       0x80000000      /* MIPS64r2 code.  */
+#define EF_MIPS_ARCH_32R6       0x90000000      /* MIPS32r6 code.  */
+#define EF_MIPS_ARCH_64R6       0xa0000000      /* MIPS64r6 code.  */
 
 /* The ABI of a file. */
 #define EF_MIPS_ABI_O32		0x00001000	/* O32 ABI.  */

linux-user/mips/target_elf.h

@@ -9,6 +9,9 @@
 #define MIPS_TARGET_ELF_H
 static inline const char *cpu_get_model(uint32_t eflags)
 {
+    if ((eflags & EF_MIPS_ARCH) == EF_MIPS_ARCH_32R6) {
+        return "mips32r6-generic";
+    }
     return "24Kf";
 }
 #endif

linux-user/mips64/target_elf.h

@@ -9,6 +9,9 @@
 #define MIPS64_TARGET_ELF_H
 static inline const char *cpu_get_model(uint32_t eflags)
 {
+    if ((eflags & EF_MIPS_ARCH) == EF_MIPS_ARCH_64R6) {
+        return "I6400";
+    }
     return "5KEf";
 }
 #endif