On 3/17/21 11:10 PM, Qiaowei Ren wrote:
> From: Coly Li <colyli@xxxxxxx>
>
> This patch initializes the prototype data structures for nvm pages
> allocator,
>
> - struct bch_nvm_pages_sb
> This is the super block allocated on each nvdimm namespace. A nvdimm
> set may have multiple namespaces, bch_nvm_pages_sb->set_uuid is used
> to mark which nvdimm set this name space belongs to. Normally we will
> use the bcache's cache set UUID to initialize this uuid, to connect this
> nvdimm set to a specified bcache cache set.
>
> - struct bch_owner_list_head
> This is a table for all heads of all owner lists. A owner list records
> which page(s) allocated to which owner. After reboot from power failure,
> the ownwer may find all its requested and allocated pages from the owner
> list by a handler which is converted by a UUID.
>
> - struct bch_nvm_pages_owner_head
> This is a head of an owner list. Each owner only has one owner list,
> and a nvm page only belongs to an specific owner. uuid[] will be set to
> owner's uuid, for bcache it is the bcache's cache set uuid. label is not
> mandatory, it is a human-readable string for debug purpose. The pointer
> *recs references to separated nvm page which hold the table of struct
> bch_nvm_pgalloc_rec.
>
> - struct bch_nvm_pgalloc_recs
> This struct occupies a whole page, owner_uuid should match the uuid
> in struct bch_nvm_pages_owner_head. recs[] is the real table contains all
> allocated records.
>
> - struct bch_nvm_pgalloc_rec
> Each structure records a range of allocated nvm pages. pgoff is offset
> in unit of page size of this allocated nvm page range. The adjoint page
> ranges of same owner can be merged into a larger one, therefore pages_nr
> is NOT always power of 2.
>
> Signed-off-by: Coly Li <colyli@xxxxxxx>
With comments from Jens, I update this header. Also I add helper
routines to get and set the allocated rec pgoff and order, which may fix
the improper bit field definiation in this series.
I will post this patch with other bcache part change soon.
Thanks.
Coly Li
> ---
> include/uapi/linux/bcache-nvm.h | 195 ++++++++++++++++++++++++++++++++
> 1 file changed, 195 insertions(+)
> create mode 100644 include/uapi/linux/bcache-nvm.h
>
> diff --git a/include/uapi/linux/bcache-nvm.h b/include/uapi/linux/bcache-nvm.h
> new file mode 100644
> index 000000000000..01370f4e12d4
> --- /dev/null
> +++ b/include/uapi/linux/bcache-nvm.h
> @@ -0,0 +1,195 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +
> +#ifndef _UAPI_BCACHE_NVM_H
> +#define _UAPI_BCACHE_NVM_H
> +
> +/*
> + * Bcache on NVDIMM data structures
> + */
> +
> +/*
> + * - struct bch_nvm_pages_sb
> + * This is the super block allocated on each nvdimm namespace. A nvdimm
> + * set may have multiple namespaces, bch_nvm_pages_sb->set_uuid is used to mark
> + * which nvdimm set this name space belongs to. Normally we will use the
> + * bcache's cache set UUID to initialize this uuid, to connect this nvdimm
> + * set to a specified bcache cache set.
> + *
> + * - struct bch_owner_list_head
> + * This is a table for all heads of all owner lists. A owner list records
> + * which page(s) allocated to which owner. After reboot from power failure,
> + * the ownwer may find all its requested and allocated pages from the owner
> + * list by a handler which is converted by a UUID.
> + *
> + * - struct bch_nvm_pages_owner_head
> + * This is a head of an owner list. Each owner only has one owner list,
> + * and a nvm page only belongs to an specific owner. uuid[] will be set to
> + * owner's uuid, for bcache it is the bcache's cache set uuid. label is not
> + * mandatory, it is a human-readable string for debug purpose. The pointer
> + * recs references to separated nvm page which hold the table of struct
> + * bch_pgalloc_rec.
> + *
> + *- struct bch_nvm_pgalloc_recs
> + * This structure occupies a whole page, owner_uuid should match the uuid
> + * in struct bch_nvm_pages_owner_head. recs[] is the real table contains all
> + * allocated records.
> + *
> + * - struct bch_pgalloc_rec
> + * Each structure records a range of allocated nvm pages. pgoff is offset
> + * in unit of page size of this allocated nvm page range. The adjoint page
> + * ranges of same owner can be merged into a larger one, therefore pages_nr
> + * is NOT always power of 2.
> + *
> + *
> + * Memory layout on nvdimm namespace 0
> + *
> + * 0 +---------------------------------+
> + * | |
> + * 4KB +---------------------------------+
> + * | bch_nvm_pages_sb |
> + * 8KB +---------------------------------+ <--- bch_nvm_pages_sb.bch_owner_list_head
> + * | bch_owner_list_head |
> + * | |
> + * 16KB +---------------------------------+ <--- bch_owner_list_head.heads[0].recs[0]
> + * | bch_nvm_pgalloc_recs |
> + * | (nvm pages internal usage) |
> + * 24KB +---------------------------------+
> + * | |
> + * | |
> + * 16MB +---------------------------------+
> + * | allocable nvm pages |
> + * | for buddy allocator |
> + * end +---------------------------------+
> + *
> + *
> + *
> + * Memory layout on nvdimm namespace N
> + * (doesn't have owner list)
> + *
> + * 0 +---------------------------------+
> + * | |
> + * 4KB +---------------------------------+
> + * | bch_nvm_pages_sb |
> + * 8KB +---------------------------------+
> + * | |
> + * | |
> + * | |
> + * | |
> + * | |
> + * | |
> + * 16MB +---------------------------------+
> + * | allocable nvm pages |
> + * | for buddy allocator |
> + * end +---------------------------------+
> + *
> + */
> +
> +#include <linux/types.h>
> +
> +/* In sectors */
> +#define BCH_NVM_PAGES_SB_OFFSET 4096
> +#define BCH_NVM_PAGES_OFFSET (16 << 20)
> +
> +#define BCH_NVM_PAGES_LABEL_SIZE 32
> +#define BCH_NVM_PAGES_NAMESPACES_MAX 8
> +
> +#define BCH_NVM_PAGES_OWNER_LIST_HEAD_OFFSET (8<<10)
> +#define BCH_NVM_PAGES_SYS_RECS_HEAD_OFFSET (16<<10)
> +
> +#define BCH_NVM_PAGES_SB_VERSION 0
> +#define BCH_NVM_PAGES_SB_VERSION_MAX 0
> +
> +static const char bch_nvm_pages_magic[] = {
> + 0x17, 0xbd, 0x53, 0x7f, 0x1b, 0x23, 0xd6, 0x83,
> + 0x46, 0xa4, 0xf8, 0x28, 0x17, 0xda, 0xec, 0xa9 };
> +static const char bch_nvm_pages_pgalloc_magic[] = {
> + 0x39, 0x25, 0x3f, 0xf7, 0x27, 0x17, 0xd0, 0xb9,
> + 0x10, 0xe6, 0xd2, 0xda, 0x38, 0x68, 0x26, 0xae };
> +
> +struct bch_pgalloc_rec {
> + __u64 pgoff:52;
> + __u64 order:12;
> +};
> +
> +struct bch_nvm_pgalloc_recs {
> +union {
> + struct {
> + struct bch_nvm_pages_owner_head *owner;
> + struct bch_nvm_pgalloc_recs *next;
> + __u8 magic[16];
> + __u8 owner_uuid[16];
> + __u32 size;
> + __u32 used;
> + __u64 _pad[4];
> + struct bch_pgalloc_rec recs[];
> + };
> + __u8 pad[8192];
> +};
> +};
> +#define BCH_MAX_REC \
> + ((sizeof(struct bch_nvm_pgalloc_recs) - \
> + offsetof(struct bch_nvm_pgalloc_recs, recs)) / \
> + sizeof(struct bch_pgalloc_rec))
> +
> +struct bch_nvm_pages_owner_head {
> + __u8 uuid[16];
> + char label[BCH_NVM_PAGES_LABEL_SIZE];
> + /* Per-namespace own lists */
> + struct bch_nvm_pgalloc_recs *recs[BCH_NVM_PAGES_NAMESPACES_MAX];
> +};
> +
> +/* heads[0] is always for nvm_pages internal usage */
> +struct bch_owner_list_head {
> +union {
> + struct {
> + __u32 size;
> + __u32 used;
> + __u64 _pad[4];
> + struct bch_nvm_pages_owner_head heads[];
> + };
> + __u8 pad[8192];
> +};
> +};
> +#define BCH_MAX_OWNER_HEAD \
> + ((sizeof(struct bch_owner_list_head) - \
> + offsetof(struct bch_owner_list_head, heads)) / \
> + sizeof(struct bch_nvm_pages_owner_head))
> +
> +/* The on-media bit order is local CPU order */
> +struct bch_nvm_pages_sb {
> + __u64 csum;
> + __u64 ns_start;
> + __u64 sb_offset;
> + __u64 version;
> + __u8 magic[16];
> + __u8 uuid[16];
> + __u32 page_size;
> + __u32 total_namespaces_nr;
> + __u32 this_namespace_nr;
> + union {
> + __u8 set_uuid[16];
> + __u64 set_magic;
> + };
> +
> + __u64 flags;
> + __u64 seq;
> +
> + __u64 feature_compat;
> + __u64 feature_incompat;
> + __u64 feature_ro_compat;
> +
> + /* For allocable nvm pages from buddy systems */
> + __u64 pages_offset;
> + __u64 pages_total;
> +
> + __u64 pad[8];
> +
> + /* Only on the first name space */
> + struct bch_owner_list_head *owner_list_head;
> +
> + /* Just for csum_set() */
> + __u32 keys;
> + __u64 d[0];
> +};
> +
> +#endif /* _UAPI_BCACHE_NVM_H */
>
