[PATCH net-next v4 2/3] page_pool: Turn dma_sync into a full-width bool field

["Toke Høiland-Jørgensen" <toke@redhat.com>]

Change the single-bit boolean for dma_sync into a full-width bool, so we
can read it as volatile with READ_ONCE(). A subsequent patch will add
writing with WRITE_ONCE() on teardown.

Reviewed-by: Mina Almasry <almasrymina@google.com>
Tested-by: Yonglong Liu <liuyonglong@huawei.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
---
 include/net/page_pool/types.h | 6 +++---
 net/core/page_pool.c          | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/include/net/page_pool/types.h b/include/net/page_pool/types.h
index df0d3c1608929605224feb26173135ff37951ef8..d6c93150384fbc4579bb0d0afb357ebb26c564a3 100644
--- a/include/net/page_pool/types.h
+++ b/include/net/page_pool/types.h
@@ -173,10 +173,10 @@ struct page_pool {
 	int cpuid;
 	u32 pages_state_hold_cnt;
 
-	bool has_init_callback:1;	/* slow::init_callback is set */
+	bool dma_sync;				/* Perform DMA sync for device */
+	bool dma_sync_for_cpu:1;		/* Perform DMA sync for cpu */
 	bool dma_map:1;			/* Perform DMA mapping */
-	bool dma_sync:1;		/* Perform DMA sync for device */
-	bool dma_sync_for_cpu:1;	/* Perform DMA sync for cpu */
+	bool has_init_callback:1;	/* slow::init_callback is set */
 #ifdef CONFIG_PAGE_POOL_STATS
 	bool system:1;			/* This is a global percpu pool */
 #endif
diff --git a/net/core/page_pool.c b/net/core/page_pool.c
index 7745ad924ae2d801580a6760eba9393e1cf67b01..c75d2add42b887f9a3a74e3fb1b3b8dc34ea72b1 100644
--- a/net/core/page_pool.c
+++ b/net/core/page_pool.c
@@ -463,7 +463,7 @@ page_pool_dma_sync_for_device(const struct page_pool *pool,
 			      netmem_ref netmem,
 			      u32 dma_sync_size)
 {
-	if (pool->dma_sync && dma_dev_need_sync(pool->p.dev))
+	if (READ_ONCE(pool->dma_sync) && dma_dev_need_sync(pool->p.dev))
 		__page_pool_dma_sync_for_device(pool, netmem, dma_sync_size);
 }
 

-- 
2.48.1