Merge branch 'devmem-tcp-fixes'

Mina Almasry says:

====================
devmem TCP fixes

Couple unrelated devmem TCP fixes bundled in a series for some
convenience.

- fix naming and provide page_pool_alloc_netmem for fragged
netmem.

- fix issues with dma-buf dma addresses being potentially
passed to dma_sync_for_* helpers.
====================

Link: https://patch.msgid.link/20241211212033.1684197-1-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/page_pool/helpers.h

@@ -115,22 +115,22 @@ static inline struct page *page_pool_dev_alloc_frag(struct page_pool *pool,
 	return page_pool_alloc_frag(pool, offset, size, gfp);
 }
 
-static inline struct page *page_pool_alloc(struct page_pool *pool,
-					   unsigned int *offset,
-					   unsigned int *size, gfp_t gfp)
+static inline netmem_ref page_pool_alloc_netmem(struct page_pool *pool,
+						unsigned int *offset,
+						unsigned int *size, gfp_t gfp)
 {
 	unsigned int max_size = PAGE_SIZE << pool->p.order;
-	struct page *page;
+	netmem_ref netmem;
 
 	if ((*size << 1) > max_size) {
 		*size = max_size;
 		*offset = 0;
-		return page_pool_alloc_pages(pool, gfp);
+		return page_pool_alloc_netmems(pool, gfp);
 	}
 
-	page = page_pool_alloc_frag(pool, offset, *size, gfp);
-	if (unlikely(!page))
-		return NULL;
+	netmem = page_pool_alloc_frag_netmem(pool, offset, *size, gfp);
+	if (unlikely(!netmem))
+		return 0;
 
 	/* There is very likely not enough space for another fragment, so append
 	 * the remaining size to the current fragment to avoid truesize
@@ -141,7 +141,14 @@ static inline struct page *page_pool_alloc(struct page_pool *pool,
 		pool->frag_offset = max_size;
 	}
 
-	return page;
+	return netmem;
+}
+
+static inline struct page *page_pool_alloc(struct page_pool *pool,
+					   unsigned int *offset,
+					   unsigned int *size, gfp_t gfp)
+{
+	return netmem_to_page(page_pool_alloc_netmem(pool, offset, size, gfp));
 }
 
 /**
@@ -415,7 +422,21 @@ static inline dma_addr_t page_pool_get_dma_addr_netmem(netmem_ref netmem)
  */
 static inline dma_addr_t page_pool_get_dma_addr(const struct page *page)
 {
-	return page_pool_get_dma_addr_netmem(page_to_netmem((struct page *)page));
+	dma_addr_t ret = page->dma_addr;
+
+	if (PAGE_POOL_32BIT_ARCH_WITH_64BIT_DMA)
+		ret <<= PAGE_SHIFT;
+
+	return ret;
+}
+
+static inline void __page_pool_dma_sync_for_cpu(const struct page_pool *pool,
+						const dma_addr_t dma_addr,
+						u32 offset, u32 dma_sync_size)
+{
+	dma_sync_single_range_for_cpu(pool->p.dev, dma_addr,
+				      offset + pool->p.offset, dma_sync_size,
+				      page_pool_get_dma_dir(pool));
 }
 
 /**
@@ -434,10 +455,21 @@ static inline void page_pool_dma_sync_for_cpu(const struct page_pool *pool,
 					      const struct page *page,
 					      u32 offset, u32 dma_sync_size)
 {
-	dma_sync_single_range_for_cpu(pool->p.dev,
-				      page_pool_get_dma_addr(page),
-				      offset + pool->p.offset, dma_sync_size,
-				      page_pool_get_dma_dir(pool));
+	__page_pool_dma_sync_for_cpu(pool, page_pool_get_dma_addr(page), offset,
+				     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->dma_sync_for_cpu)
+		return;
+
+	__page_pool_dma_sync_for_cpu(pool,
+				     page_pool_get_dma_addr_netmem(netmem),
+				     offset, dma_sync_size);
 }
 
 static inline bool page_pool_put(struct page_pool *pool)

include/net/page_pool/types.h

@@ -164,7 +164,8 @@ struct page_pool {
 
 	bool has_init_callback:1;	/* slow::init_callback is set */
 	bool dma_map:1;			/* Perform DMA mapping */
-	bool dma_sync:1;		/* Perform DMA sync */
+	bool dma_sync:1;		/* Perform DMA sync for device */
+	bool dma_sync_for_cpu:1;	/* Perform DMA sync for cpu */
 #ifdef CONFIG_PAGE_POOL_STATS
 	bool system:1;			/* This is a global percpu pool */
 #endif
@@ -242,7 +243,7 @@ struct page_pool {
 };
 
 struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp);
-netmem_ref page_pool_alloc_netmem(struct page_pool *pool, gfp_t gfp);
+netmem_ref page_pool_alloc_netmems(struct page_pool *pool, gfp_t gfp);
 struct page *page_pool_alloc_frag(struct page_pool *pool, unsigned int *offset,
 				  unsigned int size, gfp_t gfp);
 netmem_ref page_pool_alloc_frag_netmem(struct page_pool *pool,

net/core/devmem.c

@@ -331,11 +331,11 @@ int mp_dmabuf_devmem_init(struct page_pool *pool)
 	if (!binding)
 		return -EINVAL;
 
-	if (!pool->dma_map)
-		return -EOPNOTSUPP;
-
-	if (pool->dma_sync)
-		return -EOPNOTSUPP;
+	/* dma-buf dma addresses do not need and should not be used with
+	 * dma_sync_for_cpu/device. Force disable dma_sync.
+	 */
+	pool->dma_sync = false;
+	pool->dma_sync_for_cpu = false;
 
 	if (pool->p.order != 0)
 		return -E2BIG;

net/core/page_pool.c

@@ -201,6 +201,7 @@ static int page_pool_init(struct page_pool *pool,
 	memcpy(&pool->slow, &params->slow, sizeof(pool->slow));
 
 	pool->cpuid = cpuid;
+	pool->dma_sync_for_cpu = true;
 
 	/* Validate only known flags were used */
 	if (pool->slow.flags & ~PP_FLAG_ALL)
@@ -287,6 +288,9 @@ static int page_pool_init(struct page_pool *pool,
 	}
 
 	if (pool->mp_priv) {
+		if (!pool->dma_map || !pool->dma_sync)
+			return -EOPNOTSUPP;
+
 		err = mp_dmabuf_devmem_init(pool);
 		if (err) {
 			pr_warn("%s() mem-provider init failed %d\n", __func__,
@@ -574,7 +578,7 @@ static noinline netmem_ref __page_pool_alloc_pages_slow(struct page_pool *pool,
 /* For using page_pool replace: alloc_pages() API calls, but provide
  * synchronization guarantee for allocation side.
  */
-netmem_ref page_pool_alloc_netmem(struct page_pool *pool, gfp_t gfp)
+netmem_ref page_pool_alloc_netmems(struct page_pool *pool, gfp_t gfp)
 {
 	netmem_ref netmem;
 
@@ -590,11 +594,11 @@ netmem_ref page_pool_alloc_netmem(struct page_pool *pool, gfp_t gfp)
 		netmem = __page_pool_alloc_pages_slow(pool, gfp);
 	return netmem;
 }
-EXPORT_SYMBOL(page_pool_alloc_netmem);
+EXPORT_SYMBOL(page_pool_alloc_netmems);
 
 struct page *page_pool_alloc_pages(struct page_pool *pool, gfp_t gfp)
 {
-	return netmem_to_page(page_pool_alloc_netmem(pool, gfp));
+	return netmem_to_page(page_pool_alloc_netmems(pool, gfp));
 }
 EXPORT_SYMBOL(page_pool_alloc_pages);
 ALLOW_ERROR_INJECTION(page_pool_alloc_pages, NULL);
@@ -992,7 +996,7 @@ netmem_ref page_pool_alloc_frag_netmem(struct page_pool *pool,
 	}
 
 	if (!netmem) {
-		netmem = page_pool_alloc_netmem(pool, gfp);
+		netmem = page_pool_alloc_netmems(pool, gfp);
 		if (unlikely(!netmem)) {
 			pool->frag_page = 0;
 			return 0;