x86: Move range related operation to one file

[mirror_ubuntu-bionic-kernel.git] / kernel / range.c

diff --git a/kernel/range.c b/kernel/range.c
new file mode 100644 (file)
index 0000000..71e0021
--- /dev/null
+++ b/kernel/range.c
@@ -0,0 +1,163 @@
+/*
+ * Range add and subtract
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sort.h>
+
+#include <linux/range.h>
+
+#ifndef ARRAY_SIZE
+#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
+#endif
+
+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;
+
+       /* Try to merge it with old one: */
+       for (i = 0; i < nr_range; i++) {
+               u64 final_start, final_end;
+               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 + 1)
+                       continue;
+
+               final_start = min(range[i].start, start);
+               final_end = max(range[i].end, end);
+
+               range[i].start = final_start;
+               range[i].end =  final_end;
+               return nr_range;
+       }
+
+       /* 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 + 1) {
+                       range[j].start = end + 1;
+                       continue;
+               }
+
+
+               if (start > range[j].start && end >= range[j].end &&
+                   range[j].end > start - 1) {
+                       range[j].end = start - 1;
+                       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 + 1;
+                       } else {
+                               printk(KERN_ERR "run of slot in ranges\n");
+                       }
+                       range[j].end = start - 1;
+                       continue;
+               }
+       }
+}
+
+static int cmp_range(const void *x1, const void *x2)
+{
+       const struct range *r1 = x1;
+       const struct range *r2 = x2;
+       s64 start1, start2;
+
+       start1 = r1->start;
+       start2 = r2->start;
+
+       return start1 - start2;
+}
+
+int clean_sort_range(struct range *range, int az)
+{
+       int i, j, k = az - 1, nr_range = 0;
+
+       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);
+}