[MIPS] Added missing cases for rdhwr emulation

[linux-2.6] / arch / mips / kernel / traps.c

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index fcae6675297273839812a4977c329ee6cb9e5899..79cf7e913b9971f32c90a074f31fae636bebca5d 100644 (file)
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -534,8 +534,7 @@ static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
 
 /*
  * Simulate trapping 'rdhwr' instructions to provide user accessible
- * registers not implemented in hardware.  The only current use of this
- * is the thread area pointer.
+ * registers not implemented in hardware.
  */
 static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
 {
@@ -545,11 +544,31 @@ static int simulate_rdhwr(struct pt_regs *regs, unsigned int opcode)
                int rd = (opcode & RD) >> 11;
                int rt = (opcode & RT) >> 16;
                switch (rd) {
-                       case 29:
-                               regs->regs[rt] = ti->tp_value;
-                               return 0;
+               case 0:         /* CPU number */
+                       regs->regs[rt] = smp_processor_id();
+                       return 0;
+               case 1:         /* SYNCI length */
+                       regs->regs[rt] = min(current_cpu_data.dcache.linesz,
+                                            current_cpu_data.icache.linesz);
+                       return 0;
+               case 2:         /* Read count register */
+                       regs->regs[rt] = read_c0_count();
+                       return 0;
+               case 3:         /* Count register resolution */
+                       switch (current_cpu_data.cputype) {
+                       case CPU_20KC:
+                       case CPU_25KF:
+                               regs->regs[rt] = 1;
+                               break;
                        default:
-                               return -1;
+                               regs->regs[rt] = 2;
+                       }
+                       return 0;
+               case 29:
+                       regs->regs[rt] = ti->tp_value;
+                       return 0;
+               default:
+                       return -1;
                }
        }