arch.s390x.io.types Module Reference

Data Structures
struct	arch::s390x::io::ccw1
	Format-1 CCW: 8 bytes, big-endian, used with Format-1 ORB. More...
struct	arch::s390x::io::irb
	Interruption Response Block — output of TSCH instruction. Layout: SCSW(12) + ESW(20) + ECW(32) + EMW(32) = 96 bytes. More...
struct	arch::s390x::io::orb
	Operation Request Block — input to SSCH instruction. More...
struct	arch::s390x::io::pmcw
	Path Management Control Word — subchannel configuration. More...
struct	arch::s390x::io::schib
	Subchannel Information Block — returned by STSCH, input to MSCH. More...
struct	arch::s390x::io::scsw
	Subchannel Status Word — packed status from TSCH. More...
struct	arch::s390x::io::senseid_data
	Sense ID response data returned by CCW_CMD_SENSE_ID. More...
struct	arch::s390x::io::subchannel_id
	Subsystem-Identification Word (SID) for I/O instructions. More...

Functions
constexpr auto	actl () const noexcept -> u8
	Extract activity control field (PoP bits 20-26 of word 0). AC bits: 20=Resume, 21=Start, 22=Halt, 23=Clear, 24=SchActive, 25=DevActive, 26=Suspended.
constexpr auto	fctl () const noexcept -> u8
	Extract function control field (PoP bits 17-19 of word 0). FC bits: 17=Start, 18=Halt, 19=Clear.
static constexpr auto	from_parts (u8 cssid, u8 ssid, u16 sch_no) noexcept -> subchannel_id
	Construct from SSID and subchannel number.
constexpr auto	has_channel_end () const noexcept -> bool
	True if channel-end (CE) bit is set in device status.
constexpr auto	has_device_end () const noexcept -> bool
	True if device-end (DE) bit is set in device status.
constexpr auto	has_error () const noexcept -> bool
	True if any error condition is indicated.
constexpr auto	is_alert () const noexcept -> bool
	True if alert status (unsolicited primary without secondary).
constexpr auto	is_enabled () const noexcept -> bool
	True if subchannel is enabled (E bit — bit 7 of flags).
constexpr auto	is_multipath () const noexcept -> bool
	True if multipath mode is active (M bit — bit 5 of flags).
constexpr auto	is_primary () const noexcept -> bool
	True if primary status is indicated.
constexpr auto	is_secondary () const noexcept -> bool
	True if secondary status is indicated.
constexpr auto	is_solicited () const noexcept -> bool
	True if status is solicited (primary status pending).
constexpr auto	isc () const noexcept -> u8
	Extract ISC (I/O interruption subclass code, bits 2-4 of word 1). In the u16 flags field on big-endian: positions 13-11.
constexpr auto	sch_no () const noexcept -> u16
	Extract subchannel number (bits 48-63 → u32 positions 15-0).
constexpr auto	set_cpa (u32 addr) noexcept -> void
	Set the Channel Program Address (word 2, 31-bit physical).
constexpr auto	set_format1 () noexcept -> void
	Set Format-1 CCW bit (bit 8 of word 1).
constexpr auto	set_key (u8 key) noexcept -> void
	Set the storage key in bits 0-3 of word 1.
constexpr auto	set_lpm (u8 lpm) noexcept -> void
	Set the Logical Path Mask (bits 16-23 of word 1).
constexpr auto	ssid () const noexcept -> u8
	Extract subchannel set ID (bits 45-46 → u32 positions 18-17).
constexpr auto	stctl () const noexcept -> u8
	Extract status control field (PoP bits 27-31 of word 0). SC bits: 27=Alert, 28=Intermediate, 29=Primary, 30=Secondary, 31=StatusPending.
constexpr auto	to_raw () const noexcept -> u32
	Return raw 32-bit value for use in I/O instructions.

Variables
u32	_pad {0}
	Padding to 52 bytes.
u32	_reserved {0}
	Reserved.
u8	_reserved {0}
	Reserved (0xFF when valid).
u32	_reserved3 {0}
	Word 3: CSS priority (reserved for us).
u32	_reserved4 {0}
	Word 4.
u32	_reserved5 {0}
	Word 5.
u32	_reserved6 {0}
	Word 6.
u32	_reserved7 {0}
	Word 7.
constexpr u8	arch::s390x::io::ACTL_CLEAR_PEND = 0x08
	Clear pending (PoP bit 23).
constexpr u8	arch::s390x::io::ACTL_DEV_ACTIVE = 0x02
	Device active (PoP bit 25).
constexpr u8	arch::s390x::io::ACTL_HALT_PEND = 0x10
	Halt pending (PoP bit 22).
constexpr u8	arch::s390x::io::ACTL_RESUME_PEND = 0x40
	Resume pending (PoP bit 20).
constexpr u8	arch::s390x::io::ACTL_SCH_ACTIVE = 0x04
	Subchannel active (PoP bit 24).
constexpr u8	arch::s390x::io::ACTL_START_PEND = 0x20
	Start pending (PoP bit 21).
constexpr u8	arch::s390x::io::ACTL_SUSPENDED = 0x01
	Suspended (PoP bit 26).
u32	ccw_addr {0}
	Word 1: CCW address.
constexpr u8	arch::s390x::io::CCW_CMD_BASIC_SENSE = 0x04
	Basic sense.
constexpr u8	arch::s390x::io::CCW_CMD_CONTROL = 0x03
	Control.
constexpr u8	arch::s390x::io::CCW_CMD_NOP = 0x03
	No operation.
constexpr u8	arch::s390x::io::CCW_CMD_READ = 0x02
	Read.
constexpr u8	arch::s390x::io::CCW_CMD_SENSE_ID = 0xE4
	Sense ID.
constexpr u8	arch::s390x::io::CCW_CMD_TIC = 0x08
	Transfer in channel.
constexpr u8	arch::s390x::io::CCW_CMD_WRITE = 0x01
	Write.
constexpr u8	arch::s390x::io::CCW_FLAG_CC = 0x40
	Command chaining (PoP bit 9).
constexpr u8	arch::s390x::io::CCW_FLAG_CD = 0x80
	Chain data (PoP bit 8).
constexpr u8	arch::s390x::io::CCW_FLAG_IDA = 0x04
	Indirect data addressing (PoP bit 13).
constexpr u8	arch::s390x::io::CCW_FLAG_MIDA = 0x01
	Modified IDA (PoP bit 15).
constexpr u8	arch::s390x::io::CCW_FLAG_PCI = 0x08
	Program-controlled interruption (PoP bit 12).
constexpr u8	arch::s390x::io::CCW_FLAG_SKIP = 0x10
	Skip data transfer (PoP bit 11).
constexpr u8	arch::s390x::io::CCW_FLAG_SLI = 0x20
	Suppress length indication (PoP bit 10).
constexpr u8	arch::s390x::io::CCW_FLAG_SUSPEND = 0x02
	Suspend channel program (PoP bit 14).
u8	chpid [8] {}
	Channel path identifiers (one per path).
u8	cmd {}
	Byte 0: Command code.
u16	count {}
	Bytes 2-3: Byte count.
u16	count {0}
	Word 2 bits 16-31: Residual byte count.
u32	cpa {0}
	Word 2: Channel Program Address (31-bit).
u32	ctrl {0}
	Word 1: Key + control flags + LPM + ILS.
u8	cu_model {0}
	Control unit model.
u16	cu_type {0}
	Control unit type.
u32	data_addr {}
	Bytes 4-7: Data address (31-bit, bit 0 must be zero).
u8	dev_model {0}
	Device model.
constexpr u8	arch::s390x::io::DEV_STAT_ATTN = 0x80
	Attention.
constexpr u8	arch::s390x::io::DEV_STAT_BUSY = 0x10
	Busy.
constexpr u8	arch::s390x::io::DEV_STAT_CE = 0x08
	Channel end.
constexpr u8	arch::s390x::io::DEV_STAT_CUE = 0x20
	Control unit end.
constexpr u8	arch::s390x::io::DEV_STAT_DE = 0x04
	Device end.
constexpr u8	arch::s390x::io::DEV_STAT_MOD = 0x40
	Status modifier.
constexpr u8	arch::s390x::io::DEV_STAT_UC = 0x02
	Unit check.
constexpr u8	arch::s390x::io::DEV_STAT_UX = 0x01
	Unit exception.
u8	dev_status {0}
	Word 2 bits 0-7: Device status byte.
u16	dev_type {0}
	Device type.
u16	devno {0}
	Device number.
u32	ecw [8] {}
	Extended Control Word — device sense data (32 bytes).
u32	emw [8] {}
	Extended Measurement Word (32 bytes).
u32	esw [5] {}
	Extended Status Word (20 bytes) — PoP §14.3.5.
constexpr u8	arch::s390x::io::FCTL_CLEAR = 0x1
	Clear function (PoP bit 19).
constexpr u8	arch::s390x::io::FCTL_HALT = 0x2
	Halt function (PoP bit 18).
constexpr u8	arch::s390x::io::FCTL_START = 0x4
	Start function (PoP bit 17).
u8	flags {}
	Byte 1: Flag byte (CD, CC, SLI, SKIP, PCI, IDA, S, MIDA).
u16	flags {0}
	Control flags (E, LM, MM, D, T, V, ISC, etc.).
u32	flags {0}
	Word 0: key(4), control bits, FC(3), AC(7), SC(5).
u32	intparm {0}
	Word 0: Interruption parameter.
u32	intparm {0}
	Interruption parameter.
u8	lpm {0}
	Logical path mask.
u8	lpum {0}
	Last path used mask.
constexpr u16	arch::s390x::io::MAX_SCHID = 0xFFFF
	Maximum valid subchannel number (0-based).
constexpr u32	arch::s390x::io::MAX_SUBCHANNELS = 65536
	Maximum number of subchannels in the subchannel number space.
u64	mba {0}
	Measurement block address.
u16	mbi {0}
	Measurement block index.
u8	pam {0}
	Path available mask.
u8	pim {0}
	Path installed mask.
pmcw	pmcw_data {}
	Path Management Control Word.
u8	pnom {0}
	Path not operational mask.
u8	pom {0}
	Path operational mask.
constexpr u8	arch::s390x::io::SCH_STAT_CC = 0x01
	Chaining check.
constexpr u8	arch::s390x::io::SCH_STAT_CHC = 0x04
	Channel control check.
constexpr u8	arch::s390x::io::SCH_STAT_CHD = 0x08
	Channel data check.
constexpr u8	arch::s390x::io::SCH_STAT_ICC = 0x02
	Interface control check.
constexpr u8	arch::s390x::io::SCH_STAT_INCL = 0x40
	Incorrect length.
constexpr u8	arch::s390x::io::SCH_STAT_PCI = 0x80
	Program-controlled interruption.
constexpr u8	arch::s390x::io::SCH_STAT_PROG = 0x20
	Program check.
constexpr u8	arch::s390x::io::SCH_STAT_PROT = 0x10
	Protection check.
u8	sch_status {0}
	Word 2 bits 8-15: Subchannel status byte.
scsw	scsw_data {}
	Subchannel Status Word (12 bytes).
scsw	scsw_data {}
	Subchannel Status Word.
constexpr u8	arch::s390x::io::STCTL_ALERT = 0x10
	Alert status (PoP bit 27).
constexpr u8	arch::s390x::io::STCTL_INTERMEDIATE = 0x08
	Intermediate status (PoP bit 28).
constexpr u8	arch::s390x::io::STCTL_PRIMARY = 0x04
	Primary status (PoP bit 29).
constexpr u8	arch::s390x::io::STCTL_SECONDARY = 0x02
	Secondary status (PoP bit 30).
constexpr u8	arch::s390x::io::STCTL_STATUS_PEND = 0x01
	Status pending (PoP bit 31).
u32	val {0}

Files
file	arch/s390x/io/types.cxxm