1 files changed, 0 insertions, 718 deletions
diff --git a/libc/kernel/common/linux/cdrom.h b/libc/kernel/common/linux/cdrom.h
deleted file mode 100644
index cc70c9f..0000000
--- a/libc/kernel/common/linux/cdrom.h
+++ /dev/null
@@ -1,718 +0,0 @@
-/****************************************************************************
- ****************************************************************************
- ***
- ***   This header was automatically generated from a Linux kernel header
- ***   of the same name, to make information necessary for userspace to
- ***   call into the kernel available to libc.  It contains only constants,
- ***   structures, and macros generated from the original header, and thus,
- ***   contains no copyrightable information.
- ***
- ****************************************************************************
- ****************************************************************************/
-#ifndef _LINUX_CDROM_H
-#define _LINUX_CDROM_H
-
-#include <asm/byteorder.h>
-
-#define EDRIVE_CANT_DO_THIS EOPNOTSUPP
-
-#define CDROMPAUSE 0x5301   
-#define CDROMRESUME 0x5302  
-#define CDROMPLAYMSF 0x5303  
-#define CDROMPLAYTRKIND 0x5304  
-#define CDROMREADTOCHDR 0x5305  
-#define CDROMREADTOCENTRY 0x5306  
-#define CDROMSTOP 0x5307  
-#define CDROMSTART 0x5308  
-#define CDROMEJECT 0x5309  
-#define CDROMVOLCTRL 0x530a  
-#define CDROMSUBCHNL 0x530b  
-#define CDROMREADMODE2 0x530c  
-#define CDROMREADMODE1 0x530d  
-#define CDROMREADAUDIO 0x530e  
-#define CDROMEJECT_SW 0x530f  
-#define CDROMMULTISESSION 0x5310  
-#define CDROM_GET_MCN 0x5311  
-#define CDROM_GET_UPC CDROM_GET_MCN  
-#define CDROMRESET 0x5312  
-#define CDROMVOLREAD 0x5313  
-#define CDROMREADRAW 0x5314  
-
-#define CDROMREADCOOKED 0x5315  
-#define CDROMSEEK 0x5316  
-
-#define CDROMPLAYBLK 0x5317  
-
-#define CDROMREADALL 0x5318  
-
-#define CDROMGETSPINDOWN 0x531d
-#define CDROMSETSPINDOWN 0x531e
-
-#define CDROMCLOSETRAY 0x5319  
-#define CDROM_SET_OPTIONS 0x5320  
-#define CDROM_CLEAR_OPTIONS 0x5321  
-#define CDROM_SELECT_SPEED 0x5322  
-#define CDROM_SELECT_DISC 0x5323  
-#define CDROM_MEDIA_CHANGED 0x5325  
-#define CDROM_DRIVE_STATUS 0x5326  
-#define CDROM_DISC_STATUS 0x5327  
-#define CDROM_CHANGER_NSLOTS 0x5328  
-#define CDROM_LOCKDOOR 0x5329  
-#define CDROM_DEBUG 0x5330  
-#define CDROM_GET_CAPABILITY 0x5331  
-
-#define CDROMAUDIOBUFSIZ 0x5382  
-
-#define DVD_READ_STRUCT 0x5390  
-#define DVD_WRITE_STRUCT 0x5391  
-#define DVD_AUTH 0x5392  
-
-#define CDROM_SEND_PACKET 0x5393  
-#define CDROM_NEXT_WRITABLE 0x5394  
-#define CDROM_LAST_WRITTEN 0x5395  
-
-struct cdrom_msf0
-{
- __u8 minute;
- __u8 second;
- __u8 frame;
-};
-
-union cdrom_addr
-{
- struct cdrom_msf0 msf;
- int lba;
-};
-
-struct cdrom_msf
-{
- __u8 cdmsf_min0;
- __u8 cdmsf_sec0;
- __u8 cdmsf_frame0;
- __u8 cdmsf_min1;
- __u8 cdmsf_sec1;
- __u8 cdmsf_frame1;
-};
-
-struct cdrom_ti
-{
- __u8 cdti_trk0;
- __u8 cdti_ind0;
- __u8 cdti_trk1;
- __u8 cdti_ind1;
-};
-
-struct cdrom_tochdr
-{
- __u8 cdth_trk0;
- __u8 cdth_trk1;
-};
-
-struct cdrom_volctrl
-{
- __u8 channel0;
- __u8 channel1;
- __u8 channel2;
- __u8 channel3;
-};
-
-struct cdrom_subchnl
-{
- __u8 cdsc_format;
- __u8 cdsc_audiostatus;
- __u8 cdsc_adr: 4;
- __u8 cdsc_ctrl: 4;
- __u8 cdsc_trk;
- __u8 cdsc_ind;
- union cdrom_addr cdsc_absaddr;
- union cdrom_addr cdsc_reladdr;
-};
-
-struct cdrom_tocentry
-{
- __u8 cdte_track;
- __u8 cdte_adr :4;
- __u8 cdte_ctrl :4;
- __u8 cdte_format;
- union cdrom_addr cdte_addr;
- __u8 cdte_datamode;
-};
-
-struct cdrom_read
-{
- int cdread_lba;
- char *cdread_bufaddr;
- int cdread_buflen;
-};
-
-struct cdrom_read_audio
-{
- union cdrom_addr addr;
- __u8 addr_format;
- int nframes;
- __u8 __user *buf;
-};
-
-struct cdrom_multisession
-{
- union cdrom_addr addr;
- __u8 xa_flag;
- __u8 addr_format;
-};
-
-struct cdrom_mcn
-{
- __u8 medium_catalog_number[14];
-};
-
-struct cdrom_blk
-{
- unsigned from;
- unsigned short len;
-};
-
-#define CDROM_PACKET_SIZE 12
-
-#define CGC_DATA_UNKNOWN 0
-#define CGC_DATA_WRITE 1
-#define CGC_DATA_READ 2
-#define CGC_DATA_NONE 3
-
-struct cdrom_generic_command
-{
- unsigned char cmd[CDROM_PACKET_SIZE];
- unsigned char __user *buffer;
- unsigned int buflen;
- int stat;
- struct request_sense __user *sense;
- unsigned char data_direction;
- int quiet;
- int timeout;
- void __user *reserved[1];
-};
-
-#define CD_MINS 74  
-#define CD_SECS 60  
-#define CD_FRAMES 75  
-#define CD_SYNC_SIZE 12  
-#define CD_MSF_OFFSET 150  
-#define CD_CHUNK_SIZE 24  
-#define CD_NUM_OF_CHUNKS 98  
-#define CD_FRAMESIZE_SUB 96  
-#define CD_HEAD_SIZE 4  
-#define CD_SUBHEAD_SIZE 8  
-#define CD_EDC_SIZE 4  
-#define CD_ZERO_SIZE 8  
-#define CD_ECC_SIZE 276  
-#define CD_FRAMESIZE 2048  
-#define CD_FRAMESIZE_RAW 2352  
-#define CD_FRAMESIZE_RAWER 2646   
-
-#define CD_FRAMESIZE_RAW1 (CD_FRAMESIZE_RAW-CD_SYNC_SIZE)  
-#define CD_FRAMESIZE_RAW0 (CD_FRAMESIZE_RAW-CD_SYNC_SIZE-CD_HEAD_SIZE)  
-
-#define CD_XA_HEAD (CD_HEAD_SIZE+CD_SUBHEAD_SIZE)  
-#define CD_XA_TAIL (CD_EDC_SIZE+CD_ECC_SIZE)  
-#define CD_XA_SYNC_HEAD (CD_SYNC_SIZE+CD_XA_HEAD)  
-
-#define CDROM_LBA 0x01  
-#define CDROM_MSF 0x02  
-
-#define CDROM_DATA_TRACK 0x04
-
-#define CDROM_LEADOUT 0xAA
-
-#define CDROM_AUDIO_INVALID 0x00  
-#define CDROM_AUDIO_PLAY 0x11  
-#define CDROM_AUDIO_PAUSED 0x12  
-#define CDROM_AUDIO_COMPLETED 0x13  
-#define CDROM_AUDIO_ERROR 0x14  
-#define CDROM_AUDIO_NO_STATUS 0x15  
-
-#define CDC_CLOSE_TRAY 0x1  
-#define CDC_OPEN_TRAY 0x2  
-#define CDC_LOCK 0x4  
-#define CDC_SELECT_SPEED 0x8  
-#define CDC_SELECT_DISC 0x10  
-#define CDC_MULTI_SESSION 0x20  
-#define CDC_MCN 0x40  
-#define CDC_MEDIA_CHANGED 0x80  
-#define CDC_PLAY_AUDIO 0x100  
-#define CDC_RESET 0x200  
-#define CDC_DRIVE_STATUS 0x800  
-#define CDC_GENERIC_PACKET 0x1000  
-#define CDC_CD_R 0x2000  
-#define CDC_CD_RW 0x4000  
-#define CDC_DVD 0x8000  
-#define CDC_DVD_R 0x10000  
-#define CDC_DVD_RAM 0x20000  
-#define CDC_MO_DRIVE 0x40000  
-#define CDC_MRW 0x80000  
-#define CDC_MRW_W 0x100000  
-#define CDC_RAM 0x200000  
-
-#define CDS_NO_INFO 0  
-#define CDS_NO_DISC 1
-#define CDS_TRAY_OPEN 2
-#define CDS_DRIVE_NOT_READY 3
-#define CDS_DISC_OK 4
-
-#define CDS_AUDIO 100
-#define CDS_DATA_1 101
-#define CDS_DATA_2 102
-#define CDS_XA_2_1 103
-#define CDS_XA_2_2 104
-#define CDS_MIXED 105
-
-#define CDO_AUTO_CLOSE 0x1  
-#define CDO_AUTO_EJECT 0x2  
-#define CDO_USE_FFLAGS 0x4  
-#define CDO_LOCK 0x8  
-#define CDO_CHECK_TYPE 0x10  
-
-#define CDSL_NONE ((int) (~0U>>1)-1)
-#define CDSL_CURRENT ((int) (~0U>>1))
-
-#define CD_PART_MAX 64
-#define CD_PART_MASK (CD_PART_MAX - 1)
-
-#define GPCMD_BLANK 0xa1
-#define GPCMD_CLOSE_TRACK 0x5b
-#define GPCMD_FLUSH_CACHE 0x35
-#define GPCMD_FORMAT_UNIT 0x04
-#define GPCMD_GET_CONFIGURATION 0x46
-#define GPCMD_GET_EVENT_STATUS_NOTIFICATION 0x4a
-#define GPCMD_GET_PERFORMANCE 0xac
-#define GPCMD_INQUIRY 0x12
-#define GPCMD_LOAD_UNLOAD 0xa6
-#define GPCMD_MECHANISM_STATUS 0xbd
-#define GPCMD_MODE_SELECT_10 0x55
-#define GPCMD_MODE_SENSE_10 0x5a
-#define GPCMD_PAUSE_RESUME 0x4b
-#define GPCMD_PLAY_AUDIO_10 0x45
-#define GPCMD_PLAY_AUDIO_MSF 0x47
-#define GPCMD_PLAY_AUDIO_TI 0x48
-#define GPCMD_PLAY_CD 0xbc
-#define GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL 0x1e
-#define GPCMD_READ_10 0x28
-#define GPCMD_READ_12 0xa8
-#define GPCMD_READ_BUFFER_CAPACITY 0x5c
-#define GPCMD_READ_CDVD_CAPACITY 0x25
-#define GPCMD_READ_CD 0xbe
-#define GPCMD_READ_CD_MSF 0xb9
-#define GPCMD_READ_DISC_INFO 0x51
-#define GPCMD_READ_DVD_STRUCTURE 0xad
-#define GPCMD_READ_FORMAT_CAPACITIES 0x23
-#define GPCMD_READ_HEADER 0x44
-#define GPCMD_READ_TRACK_RZONE_INFO 0x52
-#define GPCMD_READ_SUBCHANNEL 0x42
-#define GPCMD_READ_TOC_PMA_ATIP 0x43
-#define GPCMD_REPAIR_RZONE_TRACK 0x58
-#define GPCMD_REPORT_KEY 0xa4
-#define GPCMD_REQUEST_SENSE 0x03
-#define GPCMD_RESERVE_RZONE_TRACK 0x53
-#define GPCMD_SEND_CUE_SHEET 0x5d
-#define GPCMD_SCAN 0xba
-#define GPCMD_SEEK 0x2b
-#define GPCMD_SEND_DVD_STRUCTURE 0xbf
-#define GPCMD_SEND_EVENT 0xa2
-#define GPCMD_SEND_KEY 0xa3
-#define GPCMD_SEND_OPC 0x54
-#define GPCMD_SET_READ_AHEAD 0xa7
-#define GPCMD_SET_STREAMING 0xb6
-#define GPCMD_START_STOP_UNIT 0x1b
-#define GPCMD_STOP_PLAY_SCAN 0x4e
-#define GPCMD_TEST_UNIT_READY 0x00
-#define GPCMD_VERIFY_10 0x2f
-#define GPCMD_WRITE_10 0x2a
-#define GPCMD_WRITE_AND_VERIFY_10 0x2e
-
-#define GPCMD_SET_SPEED 0xbb
-
-#define GPCMD_PLAYAUDIO_TI 0x48
-
-#define GPCMD_GET_MEDIA_STATUS 0xda
-
-#define GPMODE_VENDOR_PAGE 0x00
-#define GPMODE_R_W_ERROR_PAGE 0x01
-#define GPMODE_WRITE_PARMS_PAGE 0x05
-#define GPMODE_WCACHING_PAGE 0x08
-#define GPMODE_AUDIO_CTL_PAGE 0x0e
-#define GPMODE_POWER_PAGE 0x1a
-#define GPMODE_FAULT_FAIL_PAGE 0x1c
-#define GPMODE_TO_PROTECT_PAGE 0x1d
-#define GPMODE_CAPABILITIES_PAGE 0x2a
-#define GPMODE_ALL_PAGES 0x3f
-
-#define GPMODE_CDROM_PAGE 0x0d
-
-#define DVD_STRUCT_PHYSICAL 0x00
-#define DVD_STRUCT_COPYRIGHT 0x01
-#define DVD_STRUCT_DISCKEY 0x02
-#define DVD_STRUCT_BCA 0x03
-#define DVD_STRUCT_MANUFACT 0x04
-
-struct dvd_layer {
- __u8 book_version : 4;
- __u8 book_type : 4;
- __u8 min_rate : 4;
- __u8 disc_size : 4;
- __u8 layer_type : 4;
- __u8 track_path : 1;
- __u8 nlayers : 2;
- __u8 track_density : 4;
- __u8 linear_density : 4;
- __u8 bca : 1;
- __u32 start_sector;
- __u32 end_sector;
- __u32 end_sector_l0;
-};
-
-#define DVD_LAYERS 4
-
-struct dvd_physical {
- __u8 type;
- __u8 layer_num;
- struct dvd_layer layer[DVD_LAYERS];
-};
-
-struct dvd_copyright {
- __u8 type;
-
- __u8 layer_num;
- __u8 cpst;
- __u8 rmi;
-};
-
-struct dvd_disckey {
- __u8 type;
-
- unsigned agid : 2;
- __u8 value[2048];
-};
-
-struct dvd_bca {
- __u8 type;
-
- int len;
- __u8 value[188];
-};
-
-struct dvd_manufact {
- __u8 type;
-
- __u8 layer_num;
- int len;
- __u8 value[2048];
-};
-
-typedef union {
- __u8 type;
-
- struct dvd_physical physical;
- struct dvd_copyright copyright;
- struct dvd_disckey disckey;
- struct dvd_bca bca;
- struct dvd_manufact manufact;
-} dvd_struct;
-
-#define DVD_LU_SEND_AGID 0
-#define DVD_HOST_SEND_CHALLENGE 1
-#define DVD_LU_SEND_KEY1 2
-#define DVD_LU_SEND_CHALLENGE 3
-#define DVD_HOST_SEND_KEY2 4
-
-#define DVD_AUTH_ESTABLISHED 5
-#define DVD_AUTH_FAILURE 6
-
-#define DVD_LU_SEND_TITLE_KEY 7
-#define DVD_LU_SEND_ASF 8
-#define DVD_INVALIDATE_AGID 9
-#define DVD_LU_SEND_RPC_STATE 10
-#define DVD_HOST_SEND_RPC_STATE 11
-
-typedef __u8 dvd_key[5];
-typedef __u8 dvd_challenge[10];
-
-struct dvd_lu_send_agid {
- __u8 type;
- unsigned agid : 2;
-};
-
-struct dvd_host_send_challenge {
- __u8 type;
- unsigned agid : 2;
-
- dvd_challenge chal;
-};
-
-struct dvd_send_key {
- __u8 type;
- unsigned agid : 2;
-
- dvd_key key;
-};
-
-struct dvd_lu_send_challenge {
- __u8 type;
- unsigned agid : 2;
-
- dvd_challenge chal;
-};
-
-#define DVD_CPM_NO_COPYRIGHT 0
-#define DVD_CPM_COPYRIGHTED 1
-
-#define DVD_CP_SEC_NONE 0
-#define DVD_CP_SEC_EXIST 1
-
-#define DVD_CGMS_UNRESTRICTED 0
-#define DVD_CGMS_SINGLE 2
-#define DVD_CGMS_RESTRICTED 3
-
-struct dvd_lu_send_title_key {
- __u8 type;
- unsigned agid : 2;
-
- dvd_key title_key;
- int lba;
- unsigned cpm : 1;
- unsigned cp_sec : 1;
- unsigned cgms : 2;
-};
-
-struct dvd_lu_send_asf {
- __u8 type;
- unsigned agid : 2;
-
- unsigned asf : 1;
-};
-
-struct dvd_host_send_rpcstate {
- __u8 type;
- __u8 pdrc;
-};
-
-struct dvd_lu_send_rpcstate {
- __u8 type : 2;
- __u8 vra : 3;
- __u8 ucca : 3;
- __u8 region_mask;
- __u8 rpc_scheme;
-};
-
-typedef union {
- __u8 type;
-
- struct dvd_lu_send_agid lsa;
- struct dvd_host_send_challenge hsc;
- struct dvd_send_key lsk;
- struct dvd_lu_send_challenge lsc;
- struct dvd_send_key hsk;
- struct dvd_lu_send_title_key lstk;
- struct dvd_lu_send_asf lsasf;
- struct dvd_host_send_rpcstate hrpcs;
- struct dvd_lu_send_rpcstate lrpcs;
-} dvd_authinfo;
-
-struct request_sense {
-#ifdef __BIG_ENDIAN_BITFIELD
- __u8 valid : 1;
- __u8 error_code : 7;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- __u8 error_code : 7;
- __u8 valid : 1;
-#endif
- __u8 segment_number;
-#ifdef __BIG_ENDIAN_BITFIELD
- __u8 reserved1 : 2;
- __u8 ili : 1;
- __u8 reserved2 : 1;
- __u8 sense_key : 4;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- __u8 sense_key : 4;
- __u8 reserved2 : 1;
- __u8 ili : 1;
- __u8 reserved1 : 2;
-#endif
- __u8 information[4];
- __u8 add_sense_len;
- __u8 command_info[4];
- __u8 asc;
- __u8 ascq;
- __u8 fruc;
- __u8 sks[3];
- __u8 asb[46];
-};
-
-#define CDF_RWRT 0x0020  
-#define CDF_HWDM 0x0024  
-#define CDF_MRW 0x0028
-
-#define CDM_MRW_NOTMRW 0
-#define CDM_MRW_BGFORMAT_INACTIVE 1
-#define CDM_MRW_BGFORMAT_ACTIVE 2
-#define CDM_MRW_BGFORMAT_COMPLETE 3
-
-#define MRW_LBA_DMA 0
-#define MRW_LBA_GAA 1
-
-#define MRW_MODE_PC_PRE1 0x2c
-#define MRW_MODE_PC 0x03
-
-struct mrw_feature_desc {
- __u16 feature_code;
-#ifdef __BIG_ENDIAN_BITFIELD
- __u8 reserved1 : 2;
- __u8 feature_version : 4;
- __u8 persistent : 1;
- __u8 curr : 1;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- __u8 curr : 1;
- __u8 persistent : 1;
- __u8 feature_version : 4;
- __u8 reserved1 : 2;
-#endif
- __u8 add_len;
-#ifdef __BIG_ENDIAN_BITFIELD
- __u8 reserved2 : 7;
- __u8 write : 1;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- __u8 write : 1;
- __u8 reserved2 : 7;
-#endif
- __u8 reserved3;
- __u8 reserved4;
- __u8 reserved5;
-};
-
-struct rwrt_feature_desc {
- __u16 feature_code;
-#ifdef __BIG_ENDIAN_BITFIELD
- __u8 reserved1 : 2;
- __u8 feature_version : 4;
- __u8 persistent : 1;
- __u8 curr : 1;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- __u8 curr : 1;
- __u8 persistent : 1;
- __u8 feature_version : 4;
- __u8 reserved1 : 2;
-#endif
- __u8 add_len;
- __u32 last_lba;
- __u32 block_size;
- __u16 blocking;
-#ifdef __BIG_ENDIAN_BITFIELD
- __u8 reserved2 : 7;
- __u8 page_present : 1;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- __u8 page_present : 1;
- __u8 reserved2 : 7;
-#endif
- __u8 reserved3;
-};
-
-typedef struct {
- __u16 disc_information_length;
-#ifdef __BIG_ENDIAN_BITFIELD
- __u8 reserved1 : 3;
- __u8 erasable : 1;
- __u8 border_status : 2;
- __u8 disc_status : 2;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- __u8 disc_status : 2;
- __u8 border_status : 2;
- __u8 erasable : 1;
- __u8 reserved1 : 3;
-#else
-#error "Please fix <asm/byteorder.h>"
-#endif
- __u8 n_first_track;
- __u8 n_sessions_lsb;
- __u8 first_track_lsb;
- __u8 last_track_lsb;
-#ifdef __BIG_ENDIAN_BITFIELD
- __u8 did_v : 1;
- __u8 dbc_v : 1;
- __u8 uru : 1;
- __u8 reserved2 : 2;
- __u8 dbit : 1;
- __u8 mrw_status : 2;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- __u8 mrw_status : 2;
- __u8 dbit : 1;
- __u8 reserved2 : 2;
- __u8 uru : 1;
- __u8 dbc_v : 1;
- __u8 did_v : 1;
-#endif
- __u8 disc_type;
- __u8 n_sessions_msb;
- __u8 first_track_msb;
- __u8 last_track_msb;
- __u32 disc_id;
- __u32 lead_in;
- __u32 lead_out;
- __u8 disc_bar_code[8];
- __u8 reserved3;
- __u8 n_opc;
-} disc_information;
-
-typedef struct {
- __u16 track_information_length;
- __u8 track_lsb;
- __u8 session_lsb;
- __u8 reserved1;
-#ifdef __BIG_ENDIAN_BITFIELD
- __u8 reserved2 : 2;
- __u8 damage : 1;
- __u8 copy : 1;
- __u8 track_mode : 4;
- __u8 rt : 1;
- __u8 blank : 1;
- __u8 packet : 1;
- __u8 fp : 1;
- __u8 data_mode : 4;
- __u8 reserved3 : 6;
- __u8 lra_v : 1;
- __u8 nwa_v : 1;
-#elif defined(__LITTLE_ENDIAN_BITFIELD)
- __u8 track_mode : 4;
- __u8 copy : 1;
- __u8 damage : 1;
- __u8 reserved2 : 2;
- __u8 data_mode : 4;
- __u8 fp : 1;
- __u8 packet : 1;
- __u8 blank : 1;
- __u8 rt : 1;
- __u8 nwa_v : 1;
- __u8 lra_v : 1;
- __u8 reserved3 : 6;
-#endif
- __u32 track_start;
- __u32 next_writable;
- __u32 free_blocks;
- __u32 fixed_packet_size;
- __u32 track_size;
- __u32 last_rec_address;
-} track_information;
-
-struct feature_header {
- __u32 data_len;
- __u8 reserved1;
- __u8 reserved2;
- __u16 curr_profile;
-};
-
-struct mode_page_header {
- __u16 mode_data_length;
- __u8 medium_type;
- __u8 reserved1;
- __u8 reserved2;
- __u8 reserved3;
- __u16 desc_length;
-};
-
-#endif