net: fec: Fix NAPI race

[cascardo/linux.git] / mm / zsmalloc.c

diff --git a/mm/zsmalloc.c b/mm/zsmalloc.c
index 5481c67..4d0a063 100644 (file)
--- a/mm/zsmalloc.c
+++ b/mm/zsmalloc.c
@@ -155,8 +155,6 @@
  *  (reason above)
  */
 #define ZS_SIZE_CLASS_DELTA    (PAGE_SIZE >> 8)
-#define ZS_SIZE_CLASSES                ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / \
-                                       ZS_SIZE_CLASS_DELTA + 1)
 
 /*
  * We do not maintain any list for completely empty or full pages
@@ -170,6 +168,11 @@ enum fullness_group {
        ZS_FULL
 };
 
+/*
+ * number of size_classes
+ */
+static int zs_size_classes;
+
 /*
  * We assign a page to ZS_ALMOST_EMPTY fullness group when:
  *     n <= N / f, where
@@ -214,7 +217,7 @@ struct link_free {
 };
 
 struct zs_pool {
-       struct size_class *size_class[ZS_SIZE_CLASSES];
+       struct size_class **size_class;
 
        gfp_t flags;    /* allocation flags used when growing pool */
        atomic_long_t pages_allocated;
@@ -629,6 +632,7 @@ static void init_zspage(struct page *first_page, struct size_class *class)
                struct page *next_page;
                struct link_free *link;
                unsigned int i = 1;
+               void *vaddr;
 
                /*
                 * page->index stores offset of first object starting
@@ -639,8 +643,8 @@ static void init_zspage(struct page *first_page, struct size_class *class)
                if (page != first_page)
                        page->index = off;
 
-               link = (struct link_free *)kmap_atomic(page) +
-                                               off / sizeof(*link);
+               vaddr = kmap_atomic(page);
+               link = (struct link_free *)vaddr + off / sizeof(*link);
 
                while ((off += class->size) < PAGE_SIZE) {
                        link->next = obj_location_to_handle(page, i++);
@@ -654,7 +658,7 @@ static void init_zspage(struct page *first_page, struct size_class *class)
                 */
                next_page = get_next_page(page);
                link->next = obj_location_to_handle(next_page, 0);
-               kunmap_atomic(link);
+               kunmap_atomic(vaddr);
                page = next_page;
                off %= PAGE_SIZE;
        }
@@ -784,7 +788,7 @@ static inline int __zs_cpu_up(struct mapping_area *area)
         */
        if (area->vm_buf)
                return 0;
-       area->vm_buf = (char *)__get_free_page(GFP_KERNEL);
+       area->vm_buf = kmalloc(ZS_MAX_ALLOC_SIZE, GFP_KERNEL);
        if (!area->vm_buf)
                return -ENOMEM;
        return 0;
@@ -792,8 +796,7 @@ static inline int __zs_cpu_up(struct mapping_area *area)
 
 static inline void __zs_cpu_down(struct mapping_area *area)
 {
-       if (area->vm_buf)
-               free_page((unsigned long)area->vm_buf);
+       kfree(area->vm_buf);
        area->vm_buf = NULL;
 }
 
@@ -911,6 +914,17 @@ static int zs_register_cpu_notifier(void)
        return notifier_to_errno(ret);
 }
 
+static void init_zs_size_classes(void)
+{
+       int nr;
+
+       nr = (ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) / ZS_SIZE_CLASS_DELTA + 1;
+       if ((ZS_MAX_ALLOC_SIZE - ZS_MIN_ALLOC_SIZE) % ZS_SIZE_CLASS_DELTA)
+               nr += 1;
+
+       zs_size_classes = nr;
+}
+
 static void __exit zs_exit(void)
 {
 #ifdef CONFIG_ZPOOL
@@ -928,6 +942,8 @@ static int __init zs_init(void)
                return ret;
        }
 
+       init_zs_size_classes();
+
 #ifdef CONFIG_ZPOOL
        zpool_register_driver(&zs_zpool_driver);
 #endif
@@ -963,23 +979,29 @@ static bool can_merge(struct size_class *prev, int size, int pages_per_zspage)
  */
 struct zs_pool *zs_create_pool(gfp_t flags)
 {
-       int i, ovhd_size;
+       int i;
        struct zs_pool *pool;
+       struct size_class *prev_class = NULL;
 
-       ovhd_size = roundup(sizeof(*pool), PAGE_SIZE);
-       pool = kzalloc(ovhd_size, GFP_KERNEL);
+       pool = kzalloc(sizeof(*pool), GFP_KERNEL);
        if (!pool)
                return NULL;
 
+       pool->size_class = kcalloc(zs_size_classes, sizeof(struct size_class *),
+                       GFP_KERNEL);
+       if (!pool->size_class) {
+               kfree(pool);
+               return NULL;
+       }
+
        /*
         * Iterate reversly, because, size of size_class that we want to use
         * for merging should be larger or equal to current size.
         */
-       for (i = ZS_SIZE_CLASSES - 1; i >= 0; i--) {
+       for (i = zs_size_classes - 1; i >= 0; i--) {
                int size;
                int pages_per_zspage;
                struct size_class *class;
-               struct size_class *prev_class;
 
                size = ZS_MIN_ALLOC_SIZE + i * ZS_SIZE_CLASS_DELTA;
                if (size > ZS_MAX_ALLOC_SIZE)
@@ -995,8 +1017,7 @@ struct zs_pool *zs_create_pool(gfp_t flags)
                 * characteristics. So, we makes size_class point to
                 * previous size_class if possible.
                 */
-               if (i < ZS_SIZE_CLASSES - 1) {
-                       prev_class = pool->size_class[i + 1];
+               if (prev_class) {
                        if (can_merge(prev_class, size, pages_per_zspage)) {
                                pool->size_class[i] = prev_class;
                                continue;
@@ -1012,6 +1033,8 @@ struct zs_pool *zs_create_pool(gfp_t flags)
                class->pages_per_zspage = pages_per_zspage;
                spin_lock_init(&class->lock);
                pool->size_class[i] = class;
+
+               prev_class = class;
        }
 
        pool->flags = flags;
@@ -1028,7 +1051,7 @@ void zs_destroy_pool(struct zs_pool *pool)
 {
        int i;
 
-       for (i = 0; i < ZS_SIZE_CLASSES; i++) {
+       for (i = 0; i < zs_size_classes; i++) {
                int fg;
                struct size_class *class = pool->size_class[i];
 
@@ -1046,6 +1069,8 @@ void zs_destroy_pool(struct zs_pool *pool)
                }
                kfree(class);
        }
+
+       kfree(pool->size_class);
        kfree(pool);
 }
 EXPORT_SYMBOL_GPL(zs_destroy_pool);
@@ -1064,6 +1089,7 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size)
        unsigned long obj;
        struct link_free *link;
        struct size_class *class;
+       void *vaddr;
 
        struct page *first_page, *m_page;
        unsigned long m_objidx, m_offset;
@@ -1092,11 +1118,11 @@ unsigned long zs_malloc(struct zs_pool *pool, size_t size)
        obj_handle_to_location(obj, &m_page, &m_objidx);
        m_offset = obj_idx_to_offset(m_page, m_objidx, class->size);
 
-       link = (struct link_free *)kmap_atomic(m_page) +
-                                       m_offset / sizeof(*link);
+       vaddr = kmap_atomic(m_page);
+       link = (struct link_free *)vaddr + m_offset / sizeof(*link);
        first_page->freelist = link->next;
        memset(link, POISON_INUSE, sizeof(*link));
-       kunmap_atomic(link);
+       kunmap_atomic(vaddr);
 
        first_page->inuse++;
        /* Now move the zspage to another fullness group, if required */
@@ -1112,6 +1138,7 @@ void zs_free(struct zs_pool *pool, unsigned long obj)
        struct link_free *link;
        struct page *first_page, *f_page;
        unsigned long f_objidx, f_offset;
+       void *vaddr;
 
        int class_idx;
        struct size_class *class;
@@ -1130,10 +1157,10 @@ void zs_free(struct zs_pool *pool, unsigned long obj)
        spin_lock(&class->lock);
 
        /* Insert this object in containing zspage's freelist */
-       link = (struct link_free *)((unsigned char *)kmap_atomic(f_page)
-                                                       + f_offset);
+       vaddr = kmap_atomic(f_page);
+       link = (struct link_free *)(vaddr + f_offset);
        link->next = first_page->freelist;
-       kunmap_atomic(link);
+       kunmap_atomic(vaddr);
        first_page->freelist = (void *)obj;
 
        first_page->inuse--;