mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-11-11 21:38:32 +08:00
c5fcb51111
- Remove my outdated misleading email address; - Get rid of all unnecessary trailing newline by accident. Link: https://lore.kernel.org/r/20210602160634.10757-1-xiang@kernel.org Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
153 lines
3.4 KiB
C
153 lines
3.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* Copyright (C) 2018 HUAWEI, Inc.
|
|
* https://www.huawei.com/
|
|
*/
|
|
#ifndef __EROFS_FS_ZPVEC_H
|
|
#define __EROFS_FS_ZPVEC_H
|
|
|
|
#include "tagptr.h"
|
|
|
|
/* page type in pagevec for decompress subsystem */
|
|
enum z_erofs_page_type {
|
|
/* including Z_EROFS_VLE_PAGE_TAIL_EXCLUSIVE */
|
|
Z_EROFS_PAGE_TYPE_EXCLUSIVE,
|
|
|
|
Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED,
|
|
|
|
Z_EROFS_VLE_PAGE_TYPE_HEAD,
|
|
Z_EROFS_VLE_PAGE_TYPE_MAX
|
|
};
|
|
|
|
extern void __compiletime_error("Z_EROFS_PAGE_TYPE_EXCLUSIVE != 0")
|
|
__bad_page_type_exclusive(void);
|
|
|
|
/* pagevec tagged pointer */
|
|
typedef tagptr2_t erofs_vtptr_t;
|
|
|
|
/* pagevec collector */
|
|
struct z_erofs_pagevec_ctor {
|
|
struct page *curr, *next;
|
|
erofs_vtptr_t *pages;
|
|
|
|
unsigned int nr, index;
|
|
};
|
|
|
|
static inline void z_erofs_pagevec_ctor_exit(struct z_erofs_pagevec_ctor *ctor,
|
|
bool atomic)
|
|
{
|
|
if (!ctor->curr)
|
|
return;
|
|
|
|
if (atomic)
|
|
kunmap_atomic(ctor->pages);
|
|
else
|
|
kunmap(ctor->curr);
|
|
}
|
|
|
|
static inline struct page *
|
|
z_erofs_pagevec_ctor_next_page(struct z_erofs_pagevec_ctor *ctor,
|
|
unsigned int nr)
|
|
{
|
|
unsigned int index;
|
|
|
|
/* keep away from occupied pages */
|
|
if (ctor->next)
|
|
return ctor->next;
|
|
|
|
for (index = 0; index < nr; ++index) {
|
|
const erofs_vtptr_t t = ctor->pages[index];
|
|
const unsigned int tags = tagptr_unfold_tags(t);
|
|
|
|
if (tags == Z_EROFS_PAGE_TYPE_EXCLUSIVE)
|
|
return tagptr_unfold_ptr(t);
|
|
}
|
|
DBG_BUGON(nr >= ctor->nr);
|
|
return NULL;
|
|
}
|
|
|
|
static inline void
|
|
z_erofs_pagevec_ctor_pagedown(struct z_erofs_pagevec_ctor *ctor,
|
|
bool atomic)
|
|
{
|
|
struct page *next = z_erofs_pagevec_ctor_next_page(ctor, ctor->nr);
|
|
|
|
z_erofs_pagevec_ctor_exit(ctor, atomic);
|
|
|
|
ctor->curr = next;
|
|
ctor->next = NULL;
|
|
ctor->pages = atomic ?
|
|
kmap_atomic(ctor->curr) : kmap(ctor->curr);
|
|
|
|
ctor->nr = PAGE_SIZE / sizeof(struct page *);
|
|
ctor->index = 0;
|
|
}
|
|
|
|
static inline void z_erofs_pagevec_ctor_init(struct z_erofs_pagevec_ctor *ctor,
|
|
unsigned int nr,
|
|
erofs_vtptr_t *pages,
|
|
unsigned int i)
|
|
{
|
|
ctor->nr = nr;
|
|
ctor->curr = ctor->next = NULL;
|
|
ctor->pages = pages;
|
|
|
|
if (i >= nr) {
|
|
i -= nr;
|
|
z_erofs_pagevec_ctor_pagedown(ctor, false);
|
|
while (i > ctor->nr) {
|
|
i -= ctor->nr;
|
|
z_erofs_pagevec_ctor_pagedown(ctor, false);
|
|
}
|
|
}
|
|
ctor->next = z_erofs_pagevec_ctor_next_page(ctor, i);
|
|
ctor->index = i;
|
|
}
|
|
|
|
static inline bool z_erofs_pagevec_enqueue(struct z_erofs_pagevec_ctor *ctor,
|
|
struct page *page,
|
|
enum z_erofs_page_type type)
|
|
{
|
|
if (!ctor->next && type)
|
|
if (ctor->index + 1 == ctor->nr)
|
|
return false;
|
|
|
|
if (ctor->index >= ctor->nr)
|
|
z_erofs_pagevec_ctor_pagedown(ctor, false);
|
|
|
|
/* exclusive page type must be 0 */
|
|
if (Z_EROFS_PAGE_TYPE_EXCLUSIVE != (uintptr_t)NULL)
|
|
__bad_page_type_exclusive();
|
|
|
|
/* should remind that collector->next never equal to 1, 2 */
|
|
if (type == (uintptr_t)ctor->next) {
|
|
ctor->next = page;
|
|
}
|
|
ctor->pages[ctor->index++] = tagptr_fold(erofs_vtptr_t, page, type);
|
|
return true;
|
|
}
|
|
|
|
static inline struct page *
|
|
z_erofs_pagevec_dequeue(struct z_erofs_pagevec_ctor *ctor,
|
|
enum z_erofs_page_type *type)
|
|
{
|
|
erofs_vtptr_t t;
|
|
|
|
if (ctor->index >= ctor->nr) {
|
|
DBG_BUGON(!ctor->next);
|
|
z_erofs_pagevec_ctor_pagedown(ctor, true);
|
|
}
|
|
|
|
t = ctor->pages[ctor->index];
|
|
|
|
*type = tagptr_unfold_tags(t);
|
|
|
|
/* should remind that collector->next never equal to 1, 2 */
|
|
if (*type == (uintptr_t)ctor->next)
|
|
ctor->next = tagptr_unfold_ptr(t);
|
|
|
|
ctor->pages[ctor->index++] = tagptr_fold(erofs_vtptr_t, NULL, 0);
|
|
return tagptr_unfold_ptr(t);
|
|
}
|
|
#endif
|