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Diffstat (limited to 'arch/mips/kernel/traps.c')
-rw-r--r--arch/mips/kernel/traps.c31
1 files changed, 25 insertions, 6 deletions
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index fcae6675297..79cf7e913b9 100644
--- 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;
}
}