[PATCH net-next 8/9] netmem: introduce a netmem API, virt_to_head_netmem()

[Byungchul Park]

To eliminate the use of struct page in page pool, the page pool code
should use netmem descriptor and APIs instead.

As part of the work, introduce a netmem API to convert a virtual address
to a head netmem allowing the code to use it rather than the existing
API, virt_to_head_page() for struct page.

Signed-off-by: Byungchul Park <byungchul@xxxxxx>
Reviewed-by: Toke Høiland-Jørgensen <toke@xxxxxxxxxx>
Reviewed-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Reviewed-by: Mina Almasry <almasrymina@xxxxxxxxxx>
---
 include/net/netmem.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/include/net/netmem.h b/include/net/netmem.h
index d4066fcb1fee..d84ab624b489 100644
--- a/include/net/netmem.h
+++ b/include/net/netmem.h
@@ -265,6 +265,13 @@ static inline netmem_ref netmem_compound_head(netmem_ref netmem)
 	return page_to_netmem(compound_head(netmem_to_page(netmem)));
 }
 
+static inline netmem_ref virt_to_head_netmem(const void *x)
+{
+	netmem_ref netmem = virt_to_netmem(x);
+
+	return netmem_compound_head(netmem);
+}
+
 /**
  * __netmem_address - unsafely get pointer to the memory backing @netmem
  * @netmem: netmem reference to get the pointer for
-- 
2.17.1