diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index a43ebec3a7b92692f0cc970a075e2462b705e270..227c2a585e4f326a4e3355fc01f34a1eb4901b03 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -115,4 +115,10 @@ extern rwlock_t vmlist_lock;
extern struct vm_struct *vmlist;
extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);
+struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
+ const size_t *sizes, int nr_vms,
+ size_t align, gfp_t gfp_mask);
+
+void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);
+
#endif /* _LINUX_VMALLOC_H */
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 2eb461c3a46e9a9bc0095a769ee688466cab07ef..204b8243d8abb11cb9abd2f37dd8864ad0a346aa 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -265,6 +265,7 @@ struct vmap_area {
static DEFINE_SPINLOCK(vmap_area_lock);
static struct rb_root vmap_area_root = RB_ROOT;
static LIST_HEAD(vmap_area_list);
+static unsigned long vmap_area_pcpu_hole;
static struct vmap_area *__find_vmap_area(unsigned long addr)
{
@@ -431,6 +432,15 @@ static void __free_vmap_area(struct vmap_area *va)
RB_CLEAR_NODE(&va->rb_node);
list_del_rcu(&va->list);
+ /*
+ * Track the highest possible candidate for pcpu area
+ * allocation. Areas outside of vmalloc area can be returned
+ * here too, consider only end addresses which fall inside
+ * vmalloc area proper.
+ */
+ if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
+ vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);
+
call_rcu(&va->rcu_head, rcu_free_va);
}
@@ -1038,6 +1048,9 @@ void __init vmalloc_init(void)
va->va_end = va->va_start + tmp->size;
__insert_vmap_area(va);
}
+
+ vmap_area_pcpu_hole = VMALLOC_END;
+
vmap_initialized = true;
}
@@ -1821,6 +1834,286 @@ void free_vm_area(struct vm_struct *area)
}
EXPORT_SYMBOL_GPL(free_vm_area);
+static struct vmap_area *node_to_va(struct rb_node *n)
+{
+ return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
+}
+
+/**
+ * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
+ * @end: target address
+ * @pnext: out arg for the next vmap_area
+ * @pprev: out arg for the previous vmap_area
+ *
+ * Returns: %true if either or both of next and prev are found,
+ * %false if no vmap_area exists
+ *
+ * Find vmap_areas end addresses of which enclose @end. ie. if not
+ * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
+ */
+static bool pvm_find_next_prev(unsigned long end,
+ struct vmap_area **pnext,
+ struct vmap_area **pprev)
+{
+ struct rb_node *n = vmap_area_root.rb_node;
+ struct vmap_area *va = NULL;
+
+ while (n) {
+ va = rb_entry(n, struct vmap_area, rb_node);
+ if (end < va->va_end)
+ n = n->rb_left;
+ else if (end > va->va_end)
+ n = n->rb_right;
+ else
+ break;
+ }
+
+ if (!va)
+ return false;
+
+ if (va->va_end > end) {
+ *pnext = va;
+ *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+ } else {
+ *pprev = va;
+ *pnext = node_to_va(rb_next(&(*pprev)->rb_node));
+ }
+ return true;
+}
+
+/**
+ * pvm_determine_end - find the highest aligned address between two vmap_areas
+ * @pnext: in/out arg for the next vmap_area
+ * @pprev: in/out arg for the previous vmap_area
+ * @align: alignment
+ *
+ * Returns: determined end address
+ *
+ * Find the highest aligned address between *@pnext and *@pprev below
+ * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned
+ * down address is between the end addresses of the two vmap_areas.
+ *
+ * Please note that the address returned by this function may fall
+ * inside *@pnext vmap_area. The caller is responsible for checking
+ * that.
+ */
+static unsigned long pvm_determine_end(struct vmap_area **pnext,
+ struct vmap_area **pprev,
+ unsigned long align)
+{
+ const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+ unsigned long addr;
+
+ if (*pnext)
+ addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
+ else
+ addr = vmalloc_end;
+
+ while (*pprev && (*pprev)->va_end > addr) {
+ *pnext = *pprev;
+ *pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
+ }
+
+ return addr;
+}
+
+/**
+ * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
+ * @offsets: array containing offset of each area
+ * @sizes: array containing size of each area
+ * @nr_vms: the number of areas to allocate
+ * @align: alignment, all entries in @offsets and @sizes must be aligned to this
+ * @gfp_mask: allocation mask
+ *
+ * Returns: kmalloc'd vm_struct pointer array pointing to allocated
+ * vm_structs on success, %NULL on failure
+ *
+ * Percpu allocator wants to use congruent vm areas so that it can
+ * maintain the offsets among percpu areas. This function allocates
+ * congruent vmalloc areas for it. These areas tend to be scattered
+ * pretty far, distance between two areas easily going up to
+ * gigabytes. To avoid interacting with regular vmallocs, these areas
+ * are allocated from top.
+ *
+ * Despite its complicated look, this allocator is rather simple. It
+ * does everything top-down and scans areas from the end looking for
+ * matching slot. While scanning, if any of the areas overlaps with
+ * existing vmap_area, the base address is pulled down to fit the
+ * area. Scanning is repeated till all the areas fit and then all
+ * necessary data structres are inserted and the result is returned.
+ */
+struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
+ const size_t *sizes, int nr_vms,
+ size_t align, gfp_t gfp_mask)
+{
+ const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
+ const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+ struct vmap_area **vas, *prev, *next;
+ struct vm_struct **vms;
+ int area, area2, last_area, term_area;
+ unsigned long base, start, end, last_end;
+ bool purged = false;
+
+ gfp_mask &= GFP_RECLAIM_MASK;
+
+ /* verify parameters and allocate data structures */
+ BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
+ for (last_area = 0, area = 0; area < nr_vms; area++) {
+ start = offsets[area];
+ end = start + sizes[area];
+
+ /* is everything aligned properly? */
+ BUG_ON(!IS_ALIGNED(offsets[area], align));
+ BUG_ON(!IS_ALIGNED(sizes[area], align));
+
+ /* detect the area with the highest address */
+ if (start > offsets[last_area])
+ last_area = area;
+
+ for (area2 = 0; area2 < nr_vms; area2++) {
+ unsigned long start2 = offsets[area2];
+ unsigned long end2 = start2 + sizes[area2];
+
+ if (area2 == area)
+ continue;
+
+ BUG_ON(start2 >= start && start2 < end);
+ BUG_ON(end2 <= end && end2 > start);
+ }
+ }
+ last_end = offsets[last_area] + sizes[last_area];
+
+ if (vmalloc_end - vmalloc_start < last_end) {
+ WARN_ON(true);
+ return NULL;
+ }
+
+ vms = kzalloc(sizeof(vms[0]) * nr_vms, gfp_mask);
+ vas = kzalloc(sizeof(vas[0]) * nr_vms, gfp_mask);
+ if (!vas || !vms)
+ goto err_free;
+
+ for (area = 0; area < nr_vms; area++) {
+ vas[area] = kzalloc(sizeof(struct vmap_area), gfp_mask);
+ vms[area] = kzalloc(sizeof(struct vm_struct), gfp_mask);
+ if (!vas[area] || !vms[area])
+ goto err_free;
+ }
+retry:
+ spin_lock(&vmap_area_lock);
+
+ /* start scanning - we scan from the top, begin with the last area */
+ area = term_area = last_area;
+ start = offsets[area];
+ end = start + sizes[area];
+
+ if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
+ base = vmalloc_end - last_end;
+ goto found;
+ }
+ base = pvm_determine_end(&next, &prev, align) - end;
+
+ while (true) {
+ BUG_ON(next && next->va_end <= base + end);
+ BUG_ON(prev && prev->va_end > base + end);
+
+ /*
+ * base might have underflowed, add last_end before
+ * comparing.
+ */
+ if (base + last_end < vmalloc_start + last_end) {
+ spin_unlock(&vmap_area_lock);
+ if (!purged) {
+ purge_vmap_area_lazy();
+ purged = true;
+ goto retry;
+ }
+ goto err_free;
+ }
+
+ /*
+ * If next overlaps, move base downwards so that it's
+ * right below next and then recheck.
+ */
+ if (next && next->va_start < base + end) {
+ base = pvm_determine_end(&next, &prev, align) - end;
+ term_area = area;
+ continue;
+ }
+
+ /*
+ * If prev overlaps, shift down next and prev and move
+ * base so that it's right below new next and then
+ * recheck.
+ */
+ if (prev && prev->va_end > base + start) {
+ next = prev;
+ prev = node_to_va(rb_prev(&next->rb_node));
+ base = pvm_determine_end(&next, &prev, align) - end;
+ term_area = area;
+ continue;
+ }
+
+ /*
+ * This area fits, move on to the previous one. If
+ * the previous one is the terminal one, we're done.
+ */
+ area = (area + nr_vms - 1) % nr_vms;
+ if (area == term_area)
+ break;
+ start = offsets[area];
+ end = start + sizes[area];
+ pvm_find_next_prev(base + end, &next, &prev);
+ }
+found:
+ /* we've found a fitting base, insert all va's */
+ for (area = 0; area < nr_vms; area++) {
+ struct vmap_area *va = vas[area];
+
+ va->va_start = base + offsets[area];
+ va->va_end = va->va_start + sizes[area];
+ __insert_vmap_area(va);
+ }
+
+ vmap_area_pcpu_hole = base + offsets[last_area];
+
+ spin_unlock(&vmap_area_lock);
+
+ /* insert all vm's */
+ for (area = 0; area < nr_vms; area++)
+ insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
+ pcpu_get_vm_areas);
+
+ kfree(vas);
+ return vms;
+
+err_free:
+ for (area = 0; area < nr_vms; area++) {
+ if (vas)
+ kfree(vas[area]);
+ if (vms)
+ kfree(vms[area]);
+ }
+ kfree(vas);
+ kfree(vms);
+ return NULL;
+}
+
+/**
+ * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
+ * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
+ * @nr_vms: the number of allocated areas
+ *
+ * Free vm_structs and the array allocated by pcpu_get_vm_areas().
+ */
+void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
+{
+ int i;
+
+ for (i = 0; i < nr_vms; i++)
+ free_vm_area(vms[i]);
+ kfree(vms);
+}
#ifdef CONFIG_PROC_FS
static void *s_start(struct seq_file *m, loff_t *pos)