diff options
Diffstat (limited to 'arch/arm/kernel/traps.c')
| -rw-r--r-- | arch/arm/kernel/traps.c | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index bc698383e822..cdefc69c656b 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -28,6 +28,7 @@ #include <linux/irq.h> #include <linux/atomic.h> +#include <asm/arch_timer.h> #include <asm/cacheflush.h> #include <asm/exception.h> #include <asm/unistd.h> @@ -697,6 +698,42 @@ late_initcall(arm_mrc_hook_init); #endif +static int get_pct_trap(struct pt_regs *regs, unsigned int instr) +{ + u64 cntpct; + unsigned int res; + int rd = (instr >> 12) & 0xF; + int rn = (instr >> 16) & 0xF; + + res = arm_check_condition(instr, regs->ARM_cpsr); + if (res == ARM_OPCODE_CONDTEST_FAIL) { + regs->ARM_pc += 4; + return 0; + } + + if (rd == 15 || rn == 15) + return 1; + cntpct = arch_counter_get_cntpct(); + regs->uregs[rd] = cntpct; + regs->uregs[rn] = cntpct >> 32; + regs->ARM_pc += 4; + return 0; +} + +static struct undef_hook get_pct_hook = { + .instr_mask = 0x0ff00fff, + .instr_val = 0x0c500f0e, + .cpsr_mask = MODE_MASK, + .cpsr_val = USR_MODE, + .fn = get_pct_trap, +}; + +void get_pct_hook_init(void) +{ + register_undef_hook(&get_pct_hook); +} +EXPORT_SYMBOL(get_pct_hook_init); + /* * A data abort trap was taken, but we did not handle the instruction. * Try to abort the user program, or panic if it was the kernel. |