dmabuf dma-addresses should not be dma_sync'd for CPU/device. Typically
its the driver responsibility to dma_sync for CPU, but the driver should
not dma_sync for CPU if the netmem is actually coming from a dmabuf
memory provider.
The page_pool already exposes a helper for dma_sync_for_cpu:
page_pool_dma_sync_for_cpu. Upgrade this existing helper to handle
netmem, and have it skip dma_sync if the memory is from a dmabuf memory
provider. Drivers should migrate to using this helper when adding
support for netmem.
Cc: Jason Gunthorpe <jgg@xxxxxxxx>
Signed-off-by: Mina Almasry <almasrymina@xxxxxxxxxx>
---
include/net/page_pool/helpers.h | 25 +++++++++++++++++++------
1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/include/net/page_pool/helpers.h b/include/net/page_pool/helpers.h
index 8e548ff3044c..ad4fed4a791c 100644
--- a/include/net/page_pool/helpers.h
+++ b/include/net/page_pool/helpers.h
@@ -429,9 +429,10 @@ static inline dma_addr_t page_pool_get_dma_addr(const struct page *page)
}
/**
- * page_pool_dma_sync_for_cpu - sync Rx page for CPU after it's written by HW
+ * page_pool_dma_sync_netmem_for_cpu - sync Rx page for CPU after it's written
+ * by HW
* @pool: &page_pool the @page belongs to
- * @page: page to sync
+ * @netmem: netmem to sync
* @offset: offset from page start to "hard" start if using PP frags
* @dma_sync_size: size of the data written to the page
*
@@ -440,16 +441,28 @@ static inline dma_addr_t page_pool_get_dma_addr(const struct page *page)
* Note that this version performs DMA sync unconditionally, even if the
* associated PP doesn't perform sync-for-device.
*/
-static inline void page_pool_dma_sync_for_cpu(const struct page_pool *pool,
- const struct page *page,
- u32 offset, u32 dma_sync_size)
+static inline void
+page_pool_dma_sync_netmem_for_cpu(const struct page_pool *pool,
+ const netmem_ref netmem, u32 offset,
+ u32 dma_sync_size)
{
+ if (pool->mp_priv)
+ return;
+
dma_sync_single_range_for_cpu(pool->p.dev,
- page_pool_get_dma_addr(page),
+ page_pool_get_dma_addr_netmem(netmem),
offset + pool->p.offset, dma_sync_size,
page_pool_get_dma_dir(pool));
}
+static inline void page_pool_dma_sync_for_cpu(const struct page_pool *pool,
+ struct page *page, u32 offset,
+ u32 dma_sync_size)
+{
+ page_pool_dma_sync_netmem_for_cpu(pool, page_to_netmem(page), offset,
+ dma_sync_size);
+}
+
static inline bool page_pool_put(struct page_pool *pool)
{
return refcount_dec_and_test(&pool->user_cnt);
--
2.47.0.338.g60cca15819-goog
