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linux
netmem: fix netmem comments
Trivial fix to a couple of outdated netmem comments. No code changes,
just more accurately describing current code.
Signed-off-by: Mina Almasry <almasrymina@google.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250615203511.591438-1-almasrymina@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
authored by
Mina Almasry
and committed by
Jakub Kicinski
0f66b616
e74058f5
+16
-5
+16
-5
include/net/netmem.h
+16
-5
include/net/netmem.h
···
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* typedef netmem_ref - a nonexistent type marking a reference to generic
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* network memory.
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*
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* A netmem_ref currently is always a reference to a struct page. This
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* abstraction is introduced so support for new memory types can be added.
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* A netmem_ref can be a struct page* or a struct net_iov* underneath.
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*
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* Use the supplied helpers to obtain the underlying memory pointer and fields.
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*/
···
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return (__force struct page *)netmem;
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}
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/* This conversion fails (returns NULL) if the netmem_ref is not struct page
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* backed.
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*/
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static inline struct page *netmem_to_page(netmem_ref netmem)
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{
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if (WARN_ON_ONCE(netmem_is_net_iov(netmem)))
···
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return page_to_pfn(netmem_to_page(netmem));
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}
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/* __netmem_clear_lsb - convert netmem_ref to struct net_iov * for access to
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* common fields.
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* @netmem: netmem reference to extract as net_iov.
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*
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* All the sub types of netmem_ref (page, net_iov) have the same pp, pp_magic,
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* dma_addr, and pp_ref_count fields at the same offsets. Thus, we can access
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* these fields without a type check to make sure that the underlying mem is
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* net_iov or page.
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*
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* The resulting value of this function can only be used to access the fields
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* that are NET_IOV_ASSERT_OFFSET'd. Accessing any other fields will result in
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* undefined behavior.
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*
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* Return: the netmem_ref cast to net_iov* regardless of its underlying type.
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*/
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static inline struct net_iov *__netmem_clear_lsb(netmem_ref netmem)
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{
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return (struct net_iov *)((__force unsigned long)netmem & ~NET_IOV);