Input: elantech - fix detection of touchpads where the revision matches a known rate

[firefly-linux-kernel-4.4.55.git] / lib / idr.c

diff --git a/lib/idr.c b/lib/idr.c
index 322e2816f2fb6fe67b512bb4329c49e7377c1591..a3bfde8ad60e24c2e043c358048d18464705f072 100644 (file)
--- a/lib/idr.c
+++ b/lib/idr.c
@@ -250,7 +250,7 @@ static int sub_alloc(struct idr *idp, int *starting_id, struct idr_layer **pa,
                        id = (id | ((1 << (IDR_BITS * l)) - 1)) + 1;
 
                        /* if already at the top layer, we need to grow */
-                       if (id >= 1 << (idp->layers * IDR_BITS)) {
+                       if (id > idr_max(idp->layers)) {
                                *starting_id = id;
                                return -EAGAIN;
                        }
@@ -495,6 +495,33 @@ int idr_alloc(struct idr *idr, void *ptr, int start, int end, gfp_t gfp_mask)
 }
 EXPORT_SYMBOL_GPL(idr_alloc);
 
+/**
+ * idr_alloc_cyclic - allocate new idr entry in a cyclical fashion
+ * @idr: the (initialized) idr
+ * @ptr: pointer to be associated with the new id
+ * @start: the minimum id (inclusive)
+ * @end: the maximum id (exclusive, <= 0 for max)
+ * @gfp_mask: memory allocation flags
+ *
+ * Essentially the same as idr_alloc, but prefers to allocate progressively
+ * higher ids if it can. If the "cur" counter wraps, then it will start again
+ * at the "start" end of the range and allocate one that has already been used.
+ */
+int idr_alloc_cyclic(struct idr *idr, void *ptr, int start, int end,
+                       gfp_t gfp_mask)
+{
+       int id;
+
+       id = idr_alloc(idr, ptr, max(start, idr->cur), end, gfp_mask);
+       if (id == -ENOSPC)
+               id = idr_alloc(idr, ptr, start, end, gfp_mask);
+
+       if (likely(id >= 0))
+               idr->cur = id + 1;
+       return id;
+}
+EXPORT_SYMBOL(idr_alloc_cyclic);
+
 static void idr_remove_warning(int id)
 {
        printk(KERN_WARNING
@@ -802,12 +829,10 @@ void *idr_replace(struct idr *idp, void *ptr, int id)
        if (!p)
                return ERR_PTR(-EINVAL);
 
-       n = (p->layer+1) * IDR_BITS;
-
-       if (id >= (1 << n))
+       if (id > idr_max(p->layer + 1))
                return ERR_PTR(-EINVAL);
 
-       n -= IDR_BITS;
+       n = p->layer * IDR_BITS;
        while ((n > 0) && p) {
                p = p->ary[(id >> n) & IDR_MASK];
                n -= IDR_BITS;