1 files changed, 107 insertions, 0 deletions

diff --git a/drivers/misc/ocxl/pasid.c b/drivers/misc/ocxl/pasid.c
new file mode 100644
index 000000000000..d14cb56e6920
--- /dev/null
+++ b/drivers/misc/ocxl/pasid.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2017 IBM Corp.
+#include "ocxl_internal.h"
+
+
+struct id_range {
+        struct list_head list;
+        u32 start;
+        u32 end;
+};
+
+#ifdef DEBUG
+static void dump_list(struct list_head *head, char *type_str)
+{
+        struct id_range *cur;
+
+        pr_debug("%s ranges allocated:\n", type_str);
+        list_for_each_entry(cur, head, list) {
+                pr_debug("Range %d->%d\n", cur->start, cur->end);
+        }
+}
+#endif
+
+static int range_alloc(struct list_head *head, u32 size, int max_id,
+                char *type_str)
+{
+        struct list_head *pos;
+        struct id_range *cur, *new;
+        int rc, last_end;
+
+        new = kmalloc(sizeof(struct id_range), GFP_KERNEL);
+        if (!new)
+                return -ENOMEM;
+
+        pos = head;
+        last_end = -1;
+        list_for_each_entry(cur, head, list) {
+                if ((cur->start - last_end) > size)
+                        break;
+                last_end = cur->end;
+                pos = &cur->list;
+        }
+
+        new->start = last_end + 1;
+        new->end = new->start + size - 1;
+
+        if (new->end > max_id) {
+                kfree(new);
+                rc = -ENOSPC;
+        } else {
+                list_add(&new->list, pos);
+                rc = new->start;
+        }
+
+#ifdef DEBUG
+        dump_list(head, type_str);
+#endif
+        return rc;
+}
+
+static void range_free(struct list_head *head, u32 start, u32 size,
+                char *type_str)
+{
+        bool found = false;
+        struct id_range *cur, *tmp;
+
+        list_for_each_entry_safe(cur, tmp, head, list) {
+                if (cur->start == start && cur->end == (start + size - 1)) {
+                        found = true;
+                        list_del(&cur->list);
+                        kfree(cur);
+                        break;
+                }
+        }
+        WARN_ON(!found);
+#ifdef DEBUG
+        dump_list(head, type_str);
+#endif
+}
+
+int ocxl_pasid_afu_alloc(struct ocxl_fn *fn, u32 size)
+{
+        int max_pasid;
+
+        if (fn->config.max_pasid_log < 0)
+                return -ENOSPC;
+        max_pasid = 1 << fn->config.max_pasid_log;
+        return range_alloc(&fn->pasid_list, size, max_pasid, "afu pasid");
+}
+
+void ocxl_pasid_afu_free(struct ocxl_fn *fn, u32 start, u32 size)
+{
+        return range_free(&fn->pasid_list, start, size, "afu pasid");
+}
+
+int ocxl_actag_afu_alloc(struct ocxl_fn *fn, u32 size)
+{
+        int max_actag;
+
+        max_actag = fn->actag_enabled;
+        return range_alloc(&fn->actag_list, size, max_actag, "afu actag");
+}
+
+void ocxl_actag_afu_free(struct ocxl_fn *fn, u32 start, u32 size)
+{
+        return range_free(&fn->actag_list, start, size, "afu actag");
+}