28 lines · c
1#include "fbnic.h"2 3u64 fbnic_stat_rd64(struct fbnic_dev *fbd, u32 reg, u32 offset)4{5 u32 prev_upper, upper, lower, diff;6 7 prev_upper = rd32(fbd, reg + offset);8 lower = rd32(fbd, reg);9 upper = rd32(fbd, reg + offset);10 11 diff = upper - prev_upper;12 if (!diff)13 return ((u64)upper << 32) | lower;14 15 if (diff > 1)16 dev_warn_once(fbd->dev,17 "Stats inconsistent, upper 32b of %#010x updating too quickly\n",18 reg * 4);19 20 /* Return only the upper bits as we cannot guarantee21 * the accuracy of the lower bits. We will add them in22 * when the counter slows down enough that we can get23 * a snapshot with both upper values being the same24 * between reads.25 */26 return ((u64)upper << 32);27}28