diff --git a/[refs] b/[refs] index 91aa98440c67..be58bd3c2a72 100644 --- a/[refs] +++ b/[refs] @@ -1,2 +1,2 @@ --- -refs/heads/master: 64683da6643e8c6c93f1f99548399b08c029fd13 +refs/heads/master: f125be1469303f7b9324447f251d74a0da24952f diff --git a/trunk/arch/x86/oprofile/op_model_amd.c b/trunk/arch/x86/oprofile/op_model_amd.c index 6557683c190e..97c84ebe3f24 100644 --- a/trunk/arch/x86/oprofile/op_model_amd.c +++ b/trunk/arch/x86/oprofile/op_model_amd.c @@ -218,6 +218,29 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model, } } +/* + * 16-bit Linear Feedback Shift Register (LFSR) + * + * 16 14 13 11 + * Feedback polynomial = X + X + X + X + 1 + */ +static unsigned int lfsr_random(void) +{ + static unsigned int lfsr_value = 0xF00D; + unsigned int bit; + + /* Compute next bit to shift in */ + bit = ((lfsr_value >> 0) ^ + (lfsr_value >> 2) ^ + (lfsr_value >> 3) ^ + (lfsr_value >> 5)) & 0x0001; + + /* Advance to next register value */ + lfsr_value = (lfsr_value >> 1) | (bit << 15); + + return lfsr_value; +} + static inline void op_amd_handle_ibs(struct pt_regs * const regs, struct op_msrs const * const msrs)