mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-27 22:24:11 +08:00
4dec64c52e
Abstract the memory type from the page_pool so we can later add support for new memory types. Convert the page_pool to use the new netmem type abstraction, rather than use struct page directly. As of this patch the netmem type is a no-op abstraction: it's always a struct page underneath. All the page pool internals are converted to use struct netmem instead of struct page, and the page pool now exports 2 APIs: 1. The existing struct page API. 2. The new struct netmem API. Keeping the existing API is transitional; we do not want to refactor all the current drivers using the page pool at once. The netmem abstraction is currently a no-op. The page_pool uses page_to_netmem() to convert allocated pages to netmem, and uses netmem_to_page() to convert the netmem back to pages to pass to mm APIs, Follow up patches to this series add non-paged netmem support to the page_pool. This change is factored out on its own to limit the code churn to this 1 patch, for ease of code review. Signed-off-by: Mina Almasry <almasrymina@google.com> Reviewed-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://patch.msgid.link/20240628003253.1694510-6-almasrymina@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
57 lines
1.4 KiB
C
57 lines
1.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0
|
|
*
|
|
* Network memory
|
|
*
|
|
* Author: Mina Almasry <almasrymina@google.com>
|
|
*/
|
|
|
|
#ifndef _NET_NETMEM_H
|
|
#define _NET_NETMEM_H
|
|
|
|
/**
|
|
* typedef netmem_ref - a nonexistent type marking a reference to generic
|
|
* network memory.
|
|
*
|
|
* A netmem_ref currently is always a reference to a struct page. This
|
|
* abstraction is introduced so support for new memory types can be added.
|
|
*
|
|
* Use the supplied helpers to obtain the underlying memory pointer and fields.
|
|
*/
|
|
typedef unsigned long __bitwise netmem_ref;
|
|
|
|
/* This conversion fails (returns NULL) if the netmem_ref is not struct page
|
|
* backed.
|
|
*
|
|
* Currently struct page is the only possible netmem, and this helper never
|
|
* fails.
|
|
*/
|
|
static inline struct page *netmem_to_page(netmem_ref netmem)
|
|
{
|
|
return (__force struct page *)netmem;
|
|
}
|
|
|
|
/* Converting from page to netmem is always safe, because a page can always be
|
|
* a netmem.
|
|
*/
|
|
static inline netmem_ref page_to_netmem(struct page *page)
|
|
{
|
|
return (__force netmem_ref)page;
|
|
}
|
|
|
|
static inline int netmem_ref_count(netmem_ref netmem)
|
|
{
|
|
return page_ref_count(netmem_to_page(netmem));
|
|
}
|
|
|
|
static inline unsigned long netmem_to_pfn(netmem_ref netmem)
|
|
{
|
|
return page_to_pfn(netmem_to_page(netmem));
|
|
}
|
|
|
|
static inline netmem_ref netmem_compound_head(netmem_ref netmem)
|
|
{
|
|
return page_to_netmem(compound_head(netmem_to_page(netmem)));
|
|
}
|
|
|
|
#endif /* _NET_NETMEM_H */
|