mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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fc7f0dd381
Avoid overflow possibility. [ The overflow is purely theoretical, since this is used for memory ranges that aren't even close to using the full 64 bits, but this is the right thing to do regardless. - Linus ] Signed-off-by: Louis Langholtz <lou_langholtz@me.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Peter Anvin <hpa@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
164 lines
3.0 KiB
C
164 lines
3.0 KiB
C
/*
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* Range add and subtract
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*/
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/sort.h>
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#include <linux/string.h>
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#include <linux/range.h>
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int add_range(struct range *range, int az, int nr_range, u64 start, u64 end)
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{
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if (start >= end)
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return nr_range;
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/* Out of slots: */
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if (nr_range >= az)
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return nr_range;
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range[nr_range].start = start;
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range[nr_range].end = end;
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nr_range++;
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return nr_range;
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}
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int add_range_with_merge(struct range *range, int az, int nr_range,
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u64 start, u64 end)
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{
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int i;
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if (start >= end)
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return nr_range;
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/* get new start/end: */
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for (i = 0; i < nr_range; i++) {
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u64 common_start, common_end;
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if (!range[i].end)
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continue;
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common_start = max(range[i].start, start);
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common_end = min(range[i].end, end);
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if (common_start > common_end)
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continue;
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/* new start/end, will add it back at last */
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start = min(range[i].start, start);
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end = max(range[i].end, end);
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memmove(&range[i], &range[i + 1],
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(nr_range - (i + 1)) * sizeof(range[i]));
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range[nr_range - 1].start = 0;
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range[nr_range - 1].end = 0;
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nr_range--;
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i--;
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}
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/* Need to add it: */
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return add_range(range, az, nr_range, start, end);
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}
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void subtract_range(struct range *range, int az, u64 start, u64 end)
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{
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int i, j;
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if (start >= end)
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return;
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for (j = 0; j < az; j++) {
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if (!range[j].end)
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continue;
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if (start <= range[j].start && end >= range[j].end) {
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range[j].start = 0;
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range[j].end = 0;
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continue;
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}
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if (start <= range[j].start && end < range[j].end &&
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range[j].start < end) {
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range[j].start = end;
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continue;
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}
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if (start > range[j].start && end >= range[j].end &&
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range[j].end > start) {
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range[j].end = start;
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continue;
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}
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if (start > range[j].start && end < range[j].end) {
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/* Find the new spare: */
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for (i = 0; i < az; i++) {
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if (range[i].end == 0)
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break;
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}
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if (i < az) {
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range[i].end = range[j].end;
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range[i].start = end;
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} else {
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pr_err("%s: run out of slot in ranges\n",
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__func__);
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}
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range[j].end = start;
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continue;
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}
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}
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}
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static int cmp_range(const void *x1, const void *x2)
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{
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const struct range *r1 = x1;
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const struct range *r2 = x2;
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if (r1->start < r2->start)
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return -1;
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if (r1->start > r2->start)
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return 1;
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return 0;
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}
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int clean_sort_range(struct range *range, int az)
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{
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int i, j, k = az - 1, nr_range = az;
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for (i = 0; i < k; i++) {
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if (range[i].end)
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continue;
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for (j = k; j > i; j--) {
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if (range[j].end) {
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k = j;
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break;
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}
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}
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if (j == i)
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break;
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range[i].start = range[k].start;
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range[i].end = range[k].end;
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range[k].start = 0;
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range[k].end = 0;
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k--;
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}
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/* count it */
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for (i = 0; i < az; i++) {
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if (!range[i].end) {
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nr_range = i;
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break;
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}
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}
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/* sort them */
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sort(range, nr_range, sizeof(struct range), cmp_range, NULL);
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return nr_range;
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}
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void sort_range(struct range *range, int nr_range)
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{
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/* sort them */
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sort(range, nr_range, sizeof(struct range), cmp_range, NULL);
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}
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