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/* SPDX-License-Identifier: GPL-2.0-or-later */
#ifndef _BACKING_DEV_H
#define _BACKING_DEV_H
#include <linux/device-mapper.h>
#include "pcache_internal.h"
struct pcache_backing_dev_req;
typedef void (*backing_req_end_fn_t)(struct pcache_backing_dev_req *backing_req, int ret);
#define BACKING_DEV_REQ_TYPE_REQ 1
#define BACKING_DEV_REQ_TYPE_KMEM 2
#define BACKING_DEV_REQ_INLINE_BVECS 4
struct pcache_request;
struct pcache_backing_dev_req {
u8 type;
struct bio bio;
struct pcache_backing_dev *backing_dev;
void *priv_data;
backing_req_end_fn_t end_req;
struct list_head node;
int ret;
union {
struct {
struct pcache_request *upper_req;
u32 bio_off;
} req;
struct {
struct bio_vec inline_bvecs[BACKING_DEV_REQ_INLINE_BVECS];
struct bio_vec *bvecs;
u32 n_vecs;
} kmem;
};
};
struct pcache_backing_dev {
struct pcache_cache *cache;
struct dm_dev *dm_dev;
mempool_t req_pool;
mempool_t bvec_pool;
struct list_head submit_list;
spinlock_t submit_lock;
struct work_struct req_submit_work;
struct list_head complete_list;
spinlock_t complete_lock;
struct work_struct req_complete_work;
atomic_t inflight_reqs;
wait_queue_head_t inflight_wq;
u64 dev_size;
};
struct dm_pcache;
int backing_dev_start(struct dm_pcache *pcache);
void backing_dev_stop(struct dm_pcache *pcache);
struct pcache_backing_dev_req_opts {
u32 type;
union {
struct {
struct pcache_request *upper_req;
u32 req_off;
u32 len;
} req;
struct {
void *data;
blk_opf_t opf;
u32 len;
u64 backing_off;
} kmem;
};
gfp_t gfp_mask;
backing_req_end_fn_t end_fn;
void *priv_data;
};
static inline u32 backing_dev_req_coalesced_max_len(const void *data, u32 len)
{
const void *p = data;
u32 done = 0, in_page, to_advance;
struct page *first_page, *next_page;
if (!is_vmalloc_addr(data))
return len;
first_page = vmalloc_to_page(p);
advance:
in_page = PAGE_SIZE - offset_in_page(p);
to_advance = min_t(u32, in_page, len - done);
done += to_advance;
p += to_advance;
if (done == len)
return done;
next_page = vmalloc_to_page(p);
if (zone_device_pages_have_same_pgmap(first_page, next_page))
goto advance;
return done;
}
void backing_dev_req_submit(struct pcache_backing_dev_req *backing_req, bool direct);
void backing_dev_req_end(struct pcache_backing_dev_req *backing_req);
struct pcache_backing_dev_req *backing_dev_req_create(struct pcache_backing_dev *backing_dev,
struct pcache_backing_dev_req_opts *opts);
struct pcache_backing_dev_req *backing_dev_req_alloc(struct pcache_backing_dev *backing_dev,
struct pcache_backing_dev_req_opts *opts);
void backing_dev_req_init(struct pcache_backing_dev_req *backing_req,
struct pcache_backing_dev_req_opts *opts);
void backing_dev_flush(struct pcache_backing_dev *backing_dev);
int pcache_backing_init(void);
void pcache_backing_exit(void);
#endif /* _BACKING_DEV_H */
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