Lines Matching +full:error +full:- +full:counter

1 // SPDX-License-Identifier: GPL-2.0
13  * It's implemented as an unsigned 32-bit value. The low order bits are
14  * designated to hold an error code (between 0 and -MAX_ERRNO). The upper bits
15  * are used as a counter. This is done with atomics instead of locking so that
23  * frequently, since we have so few bits to use as a counter.
27  * the counter if no one has sampled it since the last time an error was
31  * is the special (but common) case where there has never been an error. An all
33  * has ever been an error set since it was first initialized.
36 /* The low bits are designated for error code (max of MAX_ERRNO) */
43 #define ERRNO_MASK		(ERRSEQ_SEEN - 1)
45 /* The lowest bit of the counter */
49  * errseq_set - set a errseq_t for later reporting
51  * @err: error to set (must be between -1 and -MAX_ERRNO)
53  * This function sets the error in @eseq, and increments the sequence counter
56  * Any error set will always overwrite an existing error.
68 	 * Ensure the error code actually fits where we want it to go. If it  in errseq_set()
71 	 * previous error.  in errseq_set()
75 	if (WARN(unlikely(err == 0 || (unsigned int)-err > MAX_ERRNO),  in errseq_set()
82 		/* Clear out error bits and set new error */  in errseq_set()
83 		new = (old & ~(ERRNO_MASK | ERRSEQ_SEEN)) | -err;  in errseq_set()
113  * errseq_sample() - Grab current errseq_t value.
117  * If the error has been "seen", new callers will not see an old error.
118  * If there is an unseen error in @eseq, the caller of this function will
119  * see it the next time it checks for an error.
128 	/* If nobody has seen this error yet, then we can be the first. */  in errseq_sample()
136  * errseq_check() - Has an error occurred since a particular sample point?
138  * @since: Previously-sampled errseq_t from which to check.
144  * Return: The latest error set in the errseq_t or 0 if it hasn't changed.
152 	return -(cur & ERRNO_MASK);  in errseq_check()
157  * errseq_check_and_advance() - Check an errseq_t and advance to current value.
159  * @since: Pointer to previously-sampled errseq_t to check against and advance.
166  * "since" value, and return whatever the error portion is set to.
173  * Return: Negative errno if one has been stored, or 0 if no new error has
183 	 * so that the common case of no error is handled without needing  in errseq_check_and_advance()
195 		 * counter or resetting the error), or another reader who is  in errseq_check_and_advance()
197 		 * can advance "since" and return an error based on what we  in errseq_check_and_advance()
204 		err = -(new & ERRNO_MASK);  in errseq_check_and_advance()