unsigned long pp_magic;
struct page_pool *pp;
unsigned long _pp_mapping_pad;
- /**
- * @dma_addr: might require a 64-bit value on
- * 32-bit architectures.
- */
- unsigned long dma_addr[2];
+ unsigned long dma_addr;
+ union {
+ /**
+ * dma_addr_upper: might require a 64-bit
+ * value on 32-bit architectures.
+ */
+ unsigned long dma_addr_upper;
+ /**
+ * For frag page support, not supported in
+ * 32-bit architectures with 64-bit DMA.
+ */
+ atomic_long_t pp_frag_count;
+ };
};
struct { /* slab, slob and slub */
union {
* Please note DMA-sync-for-CPU is still
* device driver responsibility
*/
-#define PP_FLAG_ALL (PP_FLAG_DMA_MAP | PP_FLAG_DMA_SYNC_DEV)
+#define PP_FLAG_PAGE_FRAG BIT(2) /* for page frag feature */
+#define PP_FLAG_ALL (PP_FLAG_DMA_MAP |\
+ PP_FLAG_DMA_SYNC_DEV |\
+ PP_FLAG_PAGE_FRAG)
/*
* Fast allocation side cache array/stack
page_pool_put_full_page(pool, page, true);
}
+#define PAGE_POOL_DMA_USE_PP_FRAG_COUNT \
+ (sizeof(dma_addr_t) > sizeof(unsigned long))
+
static inline dma_addr_t page_pool_get_dma_addr(struct page *page)
{
- dma_addr_t ret = page->dma_addr[0];
- if (sizeof(dma_addr_t) > sizeof(unsigned long))
- ret |= (dma_addr_t)page->dma_addr[1] << 16 << 16;
+ dma_addr_t ret = page->dma_addr;
+
+ if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT)
+ ret |= (dma_addr_t)page->dma_addr_upper << 16 << 16;
+
return ret;
}
static inline void page_pool_set_dma_addr(struct page *page, dma_addr_t addr)
{
- page->dma_addr[0] = addr;
- if (sizeof(dma_addr_t) > sizeof(unsigned long))
- page->dma_addr[1] = upper_32_bits(addr);
+ page->dma_addr = addr;
+ if (PAGE_POOL_DMA_USE_PP_FRAG_COUNT)
+ page->dma_addr_upper = upper_32_bits(addr);
+}
+
+static inline void page_pool_set_frag_count(struct page *page, long nr)
+{
+ atomic_long_set(&page->pp_frag_count, nr);
+}
+
+static inline long page_pool_atomic_sub_frag_count_return(struct page *page,
+ long nr)
+{
+ long ret;
+
+ /* As suggested by Alexander, atomic_long_read() may cover up the
+ * reference count errors, so avoid calling atomic_long_read() in
+ * the cases of freeing or draining the page_frags, where we would
+ * not expect it to match or that are slowpath anyway.
+ */
+ if (__builtin_constant_p(nr) &&
+ atomic_long_read(&page->pp_frag_count) == nr)
+ return 0;
+
+ ret = atomic_long_sub_return(nr, &page->pp_frag_count);
+ WARN_ON(ret < 0);
+ return ret;
}
static inline bool is_page_pool_compiled_in(void)