As we're about to enable trapping of some of the userspace-visible timer registers, let's add a handler for CNTFRQ.
Signed-off-by: Marc Zyngier <[email protected]> --- arch/arm/kernel/traps.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index bda12a243b40..1c1b86af20e9 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -755,9 +755,26 @@ static struct undef_hook cntvct_hook = { .fn = read_cntvct_trap, }; +static int read_cntfrq_trap(struct pt_regs *regs, unsigned int instr) +{ + int reg = (instr >> 12) & 15; + if (reg == 15) + return 1; + regs->uregs[reg] = arch_timer_get_rate(); + regs->ARM_pc += 4; + return 0; +} + +static struct undef_hook cntfrq_hook = { + .instr_mask = 0x0fff0fff, + .instr_val = 0x0e1e0f10, + .fn = read_cntfrq_trap, +}; + static int __init arch_timer_hook_init(void) { register_undef_hook(&cntvct_hook); + register_undef_hook(&cntfrq_hook); return 0; } -- 2.11.0
