linux/kernel/range.c
Andy Shevchenko b296a6d533 kernel.h: split out min()/max() et al. helpers
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt to start cleaning it up by splitting out min()/max()
et al.  helpers.

At the same time convert users in header and lib folder to use new header.
Though for time being include new header back to kernel.h to avoid
twisted indirected includes for other existing users.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Joe Perches <joe@perches.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20200910164152.GA1891694@smile.fi.intel.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-10-16 11:11:19 -07:00

166 lines
3.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Range add and subtract
*/
#include <linux/init.h>
#include <linux/minmax.h>
#include <linux/printk.h>
#include <linux/sort.h>
#include <linux/string.h>
#include <linux/range.h>
int add_range(struct range *range, int az, int nr_range, u64 start, u64 end)
{
if (start >= end)
return nr_range;
/* Out of slots: */
if (nr_range >= az)
return nr_range;
range[nr_range].start = start;
range[nr_range].end = end;
nr_range++;
return nr_range;
}
int add_range_with_merge(struct range *range, int az, int nr_range,
u64 start, u64 end)
{
int i;
if (start >= end)
return nr_range;
/* get new start/end: */
for (i = 0; i < nr_range; i++) {
u64 common_start, common_end;
if (!range[i].end)
continue;
common_start = max(range[i].start, start);
common_end = min(range[i].end, end);
if (common_start > common_end)
continue;
/* new start/end, will add it back at last */
start = min(range[i].start, start);
end = max(range[i].end, end);
memmove(&range[i], &range[i + 1],
(nr_range - (i + 1)) * sizeof(range[i]));
range[nr_range - 1].start = 0;
range[nr_range - 1].end = 0;
nr_range--;
i--;
}
/* Need to add it: */
return add_range(range, az, nr_range, start, end);
}
void subtract_range(struct range *range, int az, u64 start, u64 end)
{
int i, j;
if (start >= end)
return;
for (j = 0; j < az; j++) {
if (!range[j].end)
continue;
if (start <= range[j].start && end >= range[j].end) {
range[j].start = 0;
range[j].end = 0;
continue;
}
if (start <= range[j].start && end < range[j].end &&
range[j].start < end) {
range[j].start = end;
continue;
}
if (start > range[j].start && end >= range[j].end &&
range[j].end > start) {
range[j].end = start;
continue;
}
if (start > range[j].start && end < range[j].end) {
/* Find the new spare: */
for (i = 0; i < az; i++) {
if (range[i].end == 0)
break;
}
if (i < az) {
range[i].end = range[j].end;
range[i].start = end;
} else {
pr_err("%s: run out of slot in ranges\n",
__func__);
}
range[j].end = start;
continue;
}
}
}
static int cmp_range(const void *x1, const void *x2)
{
const struct range *r1 = x1;
const struct range *r2 = x2;
if (r1->start < r2->start)
return -1;
if (r1->start > r2->start)
return 1;
return 0;
}
int clean_sort_range(struct range *range, int az)
{
int i, j, k = az - 1, nr_range = az;
for (i = 0; i < k; i++) {
if (range[i].end)
continue;
for (j = k; j > i; j--) {
if (range[j].end) {
k = j;
break;
}
}
if (j == i)
break;
range[i].start = range[k].start;
range[i].end = range[k].end;
range[k].start = 0;
range[k].end = 0;
k--;
}
/* count it */
for (i = 0; i < az; i++) {
if (!range[i].end) {
nr_range = i;
break;
}
}
/* sort them */
sort(range, nr_range, sizeof(struct range), cmp_range, NULL);
return nr_range;
}
void sort_range(struct range *range, int nr_range)
{
/* sort them */
sort(range, nr_range, sizeof(struct range), cmp_range, NULL);
}