/* SPDX-License-Identifier: GPL-2.0 */
/*
 *  linux/fs/ufs/util.h
 *
 * Copyright (C) 1998 
 * Daniel Pirkl <daniel.pirkl@email.cz>
 * Charles University, Faculty of Mathematics and Physics
 */

#include <linux/buffer_head.h>
#include <linux/fs.h>
#include "swab.h"

/*
 * functions used for retyping
 */
static inline struct ufs_buffer_head *UCPI_UBH(struct ufs_cg_private_info *cpi)
{
        return &cpi->c_ubh;
}
static inline struct ufs_buffer_head *USPI_UBH(struct ufs_sb_private_info *spi)
{
        return &spi->s_ubh;
}



/*
 * macros used for accessing structures
 */
static inline s32
ufs_get_fs_state(struct super_block *sb, struct ufs_super_block_first *usb1,
                 struct ufs_super_block_third *usb3)
{
        switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
        case UFS_ST_SUNOS:
                if (fs32_to_cpu(sb, usb3->fs_postblformat) == UFS_42POSTBLFMT)
                        return fs32_to_cpu(sb, usb1->fs_u0.fs_sun.fs_state);
                fallthrough;    /* to UFS_ST_SUN */
        case UFS_ST_SUN:
                return fs32_to_cpu(sb, usb3->fs_un2.fs_sun.fs_state);
        case UFS_ST_SUNx86:
                return fs32_to_cpu(sb, usb1->fs_u1.fs_sunx86.fs_state);
        case UFS_ST_44BSD:
        default:
                return fs32_to_cpu(sb, usb3->fs_un2.fs_44.fs_state);
        }
}

static inline void
ufs_set_fs_state(struct super_block *sb, struct ufs_super_block_first *usb1,
                 struct ufs_super_block_third *usb3, s32 value)
{
        switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
        case UFS_ST_SUNOS:
                if (fs32_to_cpu(sb, usb3->fs_postblformat) == UFS_42POSTBLFMT) {
                        usb1->fs_u0.fs_sun.fs_state = cpu_to_fs32(sb, value);
                        break;
                }
                fallthrough;    /* to UFS_ST_SUN */
        case UFS_ST_SUN:
                usb3->fs_un2.fs_sun.fs_state = cpu_to_fs32(sb, value);
                break;
        case UFS_ST_SUNx86:
                usb1->fs_u1.fs_sunx86.fs_state = cpu_to_fs32(sb, value);
                break;
        case UFS_ST_44BSD:
                usb3->fs_un2.fs_44.fs_state = cpu_to_fs32(sb, value);
                break;
        }
}

static inline u32
ufs_get_fs_npsect(struct super_block *sb, struct ufs_super_block_first *usb1,
                  struct ufs_super_block_third *usb3)
{
        if ((UFS_SB(sb)->s_flags & UFS_ST_MASK) == UFS_ST_SUNx86)
                return fs32_to_cpu(sb, usb3->fs_un2.fs_sunx86.fs_npsect);
        else
                return fs32_to_cpu(sb, usb1->fs_u1.fs_sun.fs_npsect);
}

static inline u64
ufs_get_fs_qbmask(struct super_block *sb, struct ufs_super_block_third *usb3)
{
        __fs64 tmp;

        switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
        case UFS_ST_SUNOS:
        case UFS_ST_SUN:
                ((__fs32 *)&tmp)[0] = usb3->fs_un2.fs_sun.fs_qbmask[0];
                ((__fs32 *)&tmp)[1] = usb3->fs_un2.fs_sun.fs_qbmask[1];
                break;
        case UFS_ST_SUNx86:
                ((__fs32 *)&tmp)[0] = usb3->fs_un2.fs_sunx86.fs_qbmask[0];
                ((__fs32 *)&tmp)[1] = usb3->fs_un2.fs_sunx86.fs_qbmask[1];
                break;
        case UFS_ST_44BSD:
                ((__fs32 *)&tmp)[0] = usb3->fs_un2.fs_44.fs_qbmask[0];
                ((__fs32 *)&tmp)[1] = usb3->fs_un2.fs_44.fs_qbmask[1];
                break;
        }

        return fs64_to_cpu(sb, tmp);
}

static inline u64
ufs_get_fs_qfmask(struct super_block *sb, struct ufs_super_block_third *usb3)
{
        __fs64 tmp;

        switch (UFS_SB(sb)->s_flags & UFS_ST_MASK) {
        case UFS_ST_SUNOS:
        case UFS_ST_SUN:
                ((__fs32 *)&tmp)[0] = usb3->fs_un2.fs_sun.fs_qfmask[0];
                ((__fs32 *)&tmp)[1] = usb3->fs_un2.fs_sun.fs_qfmask[1];
                break;
        case UFS_ST_SUNx86:
                ((__fs32 *)&tmp)[0] = usb3->fs_un2.fs_sunx86.fs_qfmask[0];
                ((__fs32 *)&tmp)[1] = usb3->fs_un2.fs_sunx86.fs_qfmask[1];
                break;
        case UFS_ST_44BSD:
                ((__fs32 *)&tmp)[0] = usb3->fs_un2.fs_44.fs_qfmask[0];
                ((__fs32 *)&tmp)[1] = usb3->fs_un2.fs_44.fs_qfmask[1];
                break;
        }

        return fs64_to_cpu(sb, tmp);
}

static inline u16
ufs_get_de_namlen(struct super_block *sb, struct ufs_dir_entry *de)
{
        if ((UFS_SB(sb)->s_flags & UFS_DE_MASK) == UFS_DE_OLD)
                return fs16_to_cpu(sb, de->d_u.d_namlen);
        else
                return de->d_u.d_44.d_namlen; /* XXX this seems wrong */
}

static inline void
ufs_set_de_namlen(struct super_block *sb, struct ufs_dir_entry *de, u16 value)
{
        if ((UFS_SB(sb)->s_flags & UFS_DE_MASK) == UFS_DE_OLD)
                de->d_u.d_namlen = cpu_to_fs16(sb, value);
        else
                de->d_u.d_44.d_namlen = value; /* XXX this seems wrong */
}

static inline void
ufs_set_de_type(struct super_block *sb, struct ufs_dir_entry *de, int mode)
{
        if ((UFS_SB(sb)->s_flags & UFS_DE_MASK) != UFS_DE_44BSD)
                return;

        /*
         * TODO turn this into a table lookup
         */
        switch (mode & S_IFMT) {
        case S_IFSOCK:
                de->d_u.d_44.d_type = DT_SOCK;
                break;
        case S_IFLNK:
                de->d_u.d_44.d_type = DT_LNK;
                break;
        case S_IFREG:
                de->d_u.d_44.d_type = DT_REG;
                break;
        case S_IFBLK:
                de->d_u.d_44.d_type = DT_BLK;
                break;
        case S_IFDIR:
                de->d_u.d_44.d_type = DT_DIR;
                break;
        case S_IFCHR:
                de->d_u.d_44.d_type = DT_CHR;
                break;
        case S_IFIFO:
                de->d_u.d_44.d_type = DT_FIFO;
                break;
        default:
                de->d_u.d_44.d_type = DT_UNKNOWN;
        }
}

static inline u32
ufs_get_inode_uid(struct super_block *sb, struct ufs_inode *inode)
{
        switch (UFS_SB(sb)->s_flags & UFS_UID_MASK) {
        case UFS_UID_44BSD:
                return fs32_to_cpu(sb, inode->ui_u3.ui_44.ui_uid);
        case UFS_UID_EFT:
                if (inode->ui_u1.oldids.ui_suid == 0xFFFF)
                        return fs32_to_cpu(sb, inode->ui_u3.ui_sun.ui_uid);
                fallthrough;
        default:
                return fs16_to_cpu(sb, inode->ui_u1.oldids.ui_suid);
        }
}

static inline void
ufs_set_inode_uid(struct super_block *sb, struct ufs_inode *inode, u32 value)
{
        switch (UFS_SB(sb)->s_flags & UFS_UID_MASK) {
        case UFS_UID_44BSD:
                inode->ui_u3.ui_44.ui_uid = cpu_to_fs32(sb, value);
                inode->ui_u1.oldids.ui_suid = cpu_to_fs16(sb, value);
                break;
        case UFS_UID_EFT:
                inode->ui_u3.ui_sun.ui_uid = cpu_to_fs32(sb, value);
                if (value > 0xFFFF)
                        value = 0xFFFF;
                fallthrough;
        default:
                inode->ui_u1.oldids.ui_suid = cpu_to_fs16(sb, value);
                break;
        }
}

static inline u32
ufs_get_inode_gid(struct super_block *sb, struct ufs_inode *inode)
{
        switch (UFS_SB(sb)->s_flags & UFS_UID_MASK) {
        case UFS_UID_44BSD:
                return fs32_to_cpu(sb, inode->ui_u3.ui_44.ui_gid);
        case UFS_UID_EFT:
                if (inode->ui_u1.oldids.ui_sgid == 0xFFFF)
                        return fs32_to_cpu(sb, inode->ui_u3.ui_sun.ui_gid);
                fallthrough;
        default:
                return fs16_to_cpu(sb, inode->ui_u1.oldids.ui_sgid);
        }
}

static inline void
ufs_set_inode_gid(struct super_block *sb, struct ufs_inode *inode, u32 value)
{
        switch (UFS_SB(sb)->s_flags & UFS_UID_MASK) {
        case UFS_UID_44BSD:
                inode->ui_u3.ui_44.ui_gid = cpu_to_fs32(sb, value);
                inode->ui_u1.oldids.ui_sgid =  cpu_to_fs16(sb, value);
                break;
        case UFS_UID_EFT:
                inode->ui_u3.ui_sun.ui_gid = cpu_to_fs32(sb, value);
                if (value > 0xFFFF)
                        value = 0xFFFF;
                fallthrough;
        default:
                inode->ui_u1.oldids.ui_sgid =  cpu_to_fs16(sb, value);
                break;
        }
}

dev_t ufs_get_inode_dev(struct super_block *, struct ufs_inode_info *);
void ufs_set_inode_dev(struct super_block *, struct ufs_inode_info *, dev_t);
int ufs_prepare_chunk(struct folio *folio, loff_t pos, unsigned len);

/*
 * These functions manipulate ufs buffers
 */
#define ubh_bread(sb,fragment,size) _ubh_bread_(uspi,sb,fragment,size)  
extern struct ufs_buffer_head * _ubh_bread_(struct ufs_sb_private_info *, struct super_block *, u64 , u64);
extern struct ufs_buffer_head * ubh_bread_uspi(struct ufs_sb_private_info *, struct super_block *, u64, u64);
extern void ubh_brelse (struct ufs_buffer_head *);
extern void ubh_brelse_uspi (struct ufs_sb_private_info *);
extern void ubh_mark_buffer_dirty (struct ufs_buffer_head *);
extern void ubh_sync_block(struct ufs_buffer_head *);
extern void ubh_bforget (struct ufs_buffer_head *);
extern int  ubh_buffer_dirty (struct ufs_buffer_head *);

/* This functions works with cache pages*/
struct folio *ufs_get_locked_folio(struct address_space *mapping, pgoff_t index);
static inline void ufs_put_locked_folio(struct folio *folio)
{
       folio_unlock(folio);
       folio_put(folio);
}

/*
 * macros and inline function to get important structures from ufs_sb_private_info
 */

static inline void *get_usb_offset(struct ufs_sb_private_info *uspi,
                                   unsigned int offset)
{
        unsigned int index;
        
        index = offset >> uspi->s_fshift;
        offset &= ~uspi->s_fmask;
        return uspi->s_ubh.bh[index]->b_data + offset;
}

#define ubh_get_usb_first(uspi) \
        ((struct ufs_super_block_first *)get_usb_offset((uspi), 0))

#define ubh_get_usb_second(uspi) \
        ((struct ufs_super_block_second *)get_usb_offset((uspi), UFS_SECTOR_SIZE))

#define ubh_get_usb_third(uspi) \
        ((struct ufs_super_block_third *)get_usb_offset((uspi), 2*UFS_SECTOR_SIZE))


#define ubh_get_ucg(ubh) \
        ((struct ufs_cylinder_group *)((ubh)->bh[0]->b_data))


/*
 * Extract byte from ufs_buffer_head
 * Extract the bits for a block from a map inside ufs_buffer_head
 */
#define ubh_get_addr8(ubh,begin) \
        ((u8*)(ubh)->bh[(begin) >> uspi->s_fshift]->b_data + \
        ((begin) & ~uspi->s_fmask))

#define ubh_get_addr16(ubh,begin) \
        (((__fs16*)((ubh)->bh[(begin) >> (uspi->s_fshift-1)]->b_data)) + \
        ((begin) & ((uspi->fsize>>1) - 1)))

#define ubh_get_addr32(ubh,begin) \
        (((__fs32*)((ubh)->bh[(begin) >> (uspi->s_fshift-2)]->b_data)) + \
        ((begin) & ((uspi->s_fsize>>2) - 1)))

#define ubh_get_addr64(ubh,begin) \
        (((__fs64*)((ubh)->bh[(begin) >> (uspi->s_fshift-3)]->b_data)) + \
        ((begin) & ((uspi->s_fsize>>3) - 1)))

#define ubh_get_addr ubh_get_addr8

static inline void *ubh_get_data_ptr(struct ufs_sb_private_info *uspi,
                                     struct ufs_buffer_head *ubh,
                                     u64 blk)
{
        if (uspi->fs_magic == UFS2_MAGIC)
                return ubh_get_addr64(ubh, blk);
        else
                return ubh_get_addr32(ubh, blk);
}

#define ubh_blkmap(ubh,begin,bit) \
        ((*ubh_get_addr(ubh, (begin) + ((bit) >> 3)) >> ((bit) & 7)) & (0xff >> (UFS_MAXFRAG - uspi->s_fpb)))

static inline u64
ufs_freefrags(struct ufs_sb_private_info *uspi)
{
        return ufs_blkstofrags(uspi->cs_total.cs_nbfree) +
                uspi->cs_total.cs_nffree;
}

/*
 * Macros to access cylinder group array structures
 */
#define ubh_cg_blktot(ucpi,cylno) \
        (*((__fs32*)ubh_get_addr(UCPI_UBH(ucpi), (ucpi)->c_btotoff + ((cylno) << 2))))

#define ubh_cg_blks(ucpi,cylno,rpos) \
        (*((__fs16*)ubh_get_addr(UCPI_UBH(ucpi), \
        (ucpi)->c_boff + (((cylno) * uspi->s_nrpos + (rpos)) << 1 ))))

/*
 * Bitmap operations
 * These functions work like classical bitmap operations.
 * The difference is that we don't have the whole bitmap
 * in one contiguous chunk of memory, but in several buffers.
 * The parameters of each function are super_block, ufs_buffer_head and
 * position of the beginning of the bitmap.
 */
#define ubh_setbit(ubh,begin,bit) \
        (*ubh_get_addr(ubh, (begin) + ((bit) >> 3)) |= (1 << ((bit) & 7)))

#define ubh_clrbit(ubh,begin,bit) \
        (*ubh_get_addr (ubh, (begin) + ((bit) >> 3)) &= ~(1 << ((bit) & 7)))

#define ubh_isset(ubh,begin,bit) \
        (*ubh_get_addr (ubh, (begin) + ((bit) >> 3)) & (1 << ((bit) & 7)))

#define ubh_isclr(ubh,begin,bit) (!ubh_isset(ubh,begin,bit))

#define ubh_find_first_zero_bit(ubh,begin,size) _ubh_find_next_zero_bit_(uspi,ubh,begin,size,0)

#define ubh_find_next_zero_bit(ubh,begin,size,offset) _ubh_find_next_zero_bit_(uspi,ubh,begin,size,offset)
static inline unsigned _ubh_find_next_zero_bit_(
        struct ufs_sb_private_info * uspi, struct ufs_buffer_head * ubh,
        unsigned begin, unsigned size, unsigned offset)
{
        unsigned base, count, pos;

        size -= offset;
        begin <<= 3;
        offset += begin;
        base = offset >> uspi->s_bpfshift;
        offset &= uspi->s_bpfmask;
        for (;;) {
                count = min_t(unsigned int, size + offset, uspi->s_bpf);
                size -= count - offset;
                pos = find_next_zero_bit_le(ubh->bh[base]->b_data, count, offset);
                if (pos < count || !size)
                        break;
                base++;
                offset = 0;
        }
        return (base << uspi->s_bpfshift) + pos - begin;
}       

static inline unsigned find_last_zero_bit (unsigned char * bitmap,
        unsigned size, unsigned offset)
{
        unsigned bit, i;
        unsigned char * mapp;
        unsigned char map;

        mapp = bitmap + (size >> 3);
        map = *mapp--;
        bit = 1 << (size & 7);
        for (i = size; i > offset; i--) {
                if ((map & bit) == 0)
                        break;
                if ((i & 7) != 0) {
                        bit >>= 1;
                } else {
                        map = *mapp--;
                        bit = 1 << 7;
                }
        }
        return i;
}

#define ubh_find_last_zero_bit(ubh,begin,size,offset) _ubh_find_last_zero_bit_(uspi,ubh,begin,size,offset)
static inline unsigned _ubh_find_last_zero_bit_(
        struct ufs_sb_private_info * uspi, struct ufs_buffer_head * ubh,
        unsigned begin, unsigned start, unsigned end)
{
        unsigned base, count, pos, size;

        size = start - end;
        begin <<= 3;
        start += begin;
        base = start >> uspi->s_bpfshift;
        start &= uspi->s_bpfmask;
        for (;;) {
                count = min_t(unsigned int,
                            size + (uspi->s_bpf - start), uspi->s_bpf)
                        - (uspi->s_bpf - start);
                size -= count;
                pos = find_last_zero_bit (ubh->bh[base]->b_data,
                        start, start - count);
                if (pos > start - count || !size)
                        break;
                base--;
                start = uspi->s_bpf;
        }
        return (base << uspi->s_bpfshift) + pos - begin;
}       

static inline int ubh_isblockset(struct ufs_sb_private_info *uspi,
        struct ufs_cg_private_info *ucpi, unsigned int frag)
{
        struct ufs_buffer_head *ubh = UCPI_UBH(ucpi);
        u8 *p = ubh_get_addr(ubh, ucpi->c_freeoff + (frag >> 3));
        u8 mask;

        switch (uspi->s_fpb) {
        case 8:
                return *p == 0xff;
        case 4:
                mask = 0x0f << (frag & 4);
                return (*p & mask) == mask;
        case 2:
                mask = 0x03 << (frag & 6);
                return (*p & mask) == mask;
        case 1:
                mask = 0x01 << (frag & 7);
                return (*p & mask) == mask;
        }
        return 0;       
}

static inline void ubh_clrblock(struct ufs_sb_private_info *uspi,
        struct ufs_cg_private_info *ucpi, unsigned int frag)
{
        struct ufs_buffer_head *ubh = UCPI_UBH(ucpi);
        u8 *p = ubh_get_addr(ubh, ucpi->c_freeoff + (frag >> 3));

        switch (uspi->s_fpb) {
        case 8:
                *p = 0x00;
                return; 
        case 4:
                *p &= ~(0x0f << (frag & 4));
                return;
        case 2:
                *p &= ~(0x03 << (frag & 6));
                return;
        case 1:
                *p &= ~(0x01 << (frag & 7));
                return;
        }
}

static inline void ubh_setblock(struct ufs_sb_private_info * uspi,
        struct ufs_cg_private_info *ucpi, unsigned int frag)
{
        struct ufs_buffer_head *ubh = UCPI_UBH(ucpi);
        u8 *p = ubh_get_addr(ubh, ucpi->c_freeoff + (frag >> 3));

        switch (uspi->s_fpb) {
        case 8:
                *p = 0xff;
                return;
        case 4:
                *p |= 0x0f << (frag & 4);
                return;
        case 2:
                *p |= 0x03 << (frag & 6);
                return;
        case 1:
                *p |= 0x01 << (frag & 7);
                return;
        }
}

static inline void ufs_fragacct (struct super_block * sb, unsigned blockmap,
        __fs32 * fraglist, int cnt)
{
        struct ufs_sb_private_info * uspi;
        unsigned fragsize, pos;
        
        uspi = UFS_SB(sb)->s_uspi;
        
        fragsize = 0;
        for (pos = 0; pos < uspi->s_fpb; pos++) {
                if (blockmap & (1 << pos)) {
                        fragsize++;
                }
                else if (fragsize > 0) {
                        fs32_add(sb, &fraglist[fragsize], cnt);
                        fragsize = 0;
                }
        }
        if (fragsize > 0 && fragsize < uspi->s_fpb)
                fs32_add(sb, &fraglist[fragsize], cnt);
}

static inline void *ufs_get_direct_data_ptr(struct ufs_sb_private_info *uspi,
                                            struct ufs_inode_info *ufsi,
                                            unsigned blk)
{
        BUG_ON(blk > UFS_TIND_BLOCK);
        return uspi->fs_magic == UFS2_MAGIC ?
                (void *)&ufsi->i_u1.u2_i_data[blk] :
                (void *)&ufsi->i_u1.i_data[blk];
}

static inline u64 ufs_data_ptr_to_cpu(struct super_block *sb, void *p)
{
        return UFS_SB(sb)->s_uspi->fs_magic == UFS2_MAGIC ?
                fs64_to_cpu(sb, *(__fs64 *)p) :
                fs32_to_cpu(sb, *(__fs32 *)p);
}

static inline void ufs_cpu_to_data_ptr(struct super_block *sb, void *p, u64 val)
{
        if (UFS_SB(sb)->s_uspi->fs_magic == UFS2_MAGIC)
                *(__fs64 *)p = cpu_to_fs64(sb, val);
        else
                *(__fs32 *)p = cpu_to_fs32(sb, val);
}

static inline void ufs_data_ptr_clear(struct ufs_sb_private_info *uspi,
                                      void *p)
{
        if (uspi->fs_magic == UFS2_MAGIC)
                *(__fs64 *)p = 0;
        else
                *(__fs32 *)p = 0;
}

static inline int ufs_is_data_ptr_zero(struct ufs_sb_private_info *uspi,
                                       void *p)
{
        if (uspi->fs_magic == UFS2_MAGIC)
                return *(__fs64 *)p == 0;
        else
                return *(__fs32 *)p == 0;
}

static inline __fs32 ufs_get_seconds(struct super_block *sbp)
{
        time64_t now = ktime_get_real_seconds();

        /* Signed 32-bit interpretation wraps around in 2038, which
         * happens in ufs1 inode stamps but not ufs2 using 64-bits
         * stamps. For superblock and blockgroup, let's assume
         * unsigned 32-bit stamps, which are good until y2106.
         * Wrap around rather than clamp here to make the dirty
         * file system detection work in the superblock stamp.
         */
        return cpu_to_fs32(sbp, lower_32_bits(now));
}