2:272
Volume 2, Part 1: Itanium
®
Architecture-based Operating System Interaction Model with IA-32 Applications
• If data translations are disabled (PSR.dt is 0) or the referenced I/O port is mapped
to an unimplemented virtual address (via the IOBase register), a GPFault is raised
on the referencing IA-32 IN, OUT, INS, or OUTS instruction.
• Alignment and Data Address breakpoints are also checked and may result in an
IA_32_Exception(AlignmentCheck) fault (if PSR.ac is 1) or
IA_32_Exception(Debug) trap.
• If an IA-32 IN/OUT I/O port Accesses cross a 4-port boundary the processor will
break the operation into smaller 1, 2, or 3 byte transactions.
• Assuming no faults, a physical transaction is emitted to the mapped or specified
physical address.
The processor ensures that IA-32 IN, INS, OUT, OUTS references are fully ordered and
will not allow prior or future data memory references to pass the I/O operation as
defined in
Section 10.6.10, “IA-32 Memory Ordering” on page 2:265
. The processor will
wait for acceptance for IN and OUT operations before proceeding with subsequent
externally visible bus transactions.
10.7.4
I/O Port Accesses by Loads and Stores
If an access is made to the I/O port block using IA-32 or Itanium loads and stores the
following differences in behavior should be noted; EFLAG.iopl permission is not
checked, TSS permission bitmap is not checked, and stores and loads do not honor IN
and OUT memory ordering and acceptance semantics (the processor will not
automatically wait for a store to be accepted by the platform).
Virtual addresses for the I/O port space should be computed as defined in
Section 10.7.1, “Virtual I/O Port Addressing” on page 2:268
If data translations are
enabled, the TLB is consulted for mappings and permission, and the resulting mapped
physical address used to address the physical I/O device.
If IA-32 ordering semantics are required to a particular I/O port device (or memory
mapped I/O device), IA-32 or Itanium architecture-based software must enforce
ordering to the I/O device. Software can either perform a memory ordering fence
before and after the transaction, or use an load acquire or store release
To ensure the processor does not speculatively access an I/O device, all I/O devices
must be mapped by the UC memory attribute.
If IA-32 acceptance semantics are required (i.e. additional data memory transactions
are not initiated until the I/O transaction is completed), Itanium architecture-based
code can issue a memory acceptance fence. Conversely, if certain I/O devices do not
require IA-32 IN/OUT ordering or acceptance semantics, Itanium architecture-based
code can relax ordering and acceptance requirements as shown below.
OUT
[mf]//Fence prior memory references, if required
add port_addr = IO_Port_Base, Expanded_Port_Number
st.rel (port_addr), data
[mf.a] //Wait for platform acceptance, if required
[mf]
//Fence future memory operations, if required
Содержание ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3
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Страница 11: ...x Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 12: ...1 1 Intel Itanium Architecture Software Developer s Manual Rev 2 3 Part I Application Architecture Guide ...
Страница 13: ...1 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 33: ...1 22 Volume 1 Part 1 Introduction to the Intel Itanium Architecture ...
Страница 57: ...1 46 Volume 1 Part 1 Execution Environment ...
Страница 147: ...1 136 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 149: ...1 138 Volume 1 Part 2 About the Optimization Guide ...
Страница 191: ...1 180 Volume 1 Part 2 Predication Control Flow and Instruction Stream ...
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Страница 249: ...2 1 Intel Itanium Architecture Software Developer s Manual Rev 2 3 Part I System Architecture Guide ...
Страница 250: ...2 2 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 264: ...2 16 Volume 2 Part 1 Intel Itanium System Environment ...
Страница 380: ...2 132 Volume 2 Part 1 Interruptions ...
Страница 398: ...2 150 Volume 2 Part 1 Register Stack Engine ...
Страница 486: ...2 238 Volume 2 Part 1 IA 32 Interruption Vector Descriptions ...
Страница 749: ...2 501 Intel Itanium Architecture Software Developer s Manual Rev 2 3 Part II System Programmer s Guide ...
Страница 750: ...2 502 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 754: ...2 506 Volume 2 Part 2 About the System Programmer s Guide ...
Страница 796: ...2 548 Volume 2 Part 2 Interruptions and Serialization ...
Страница 808: ...2 560 Volume 2 Part 2 Context Management ...
Страница 842: ...2 594 Volume 2 Part 2 Floating point System Software ...
Страница 850: ...2 602 Volume 2 Part 2 IA 32 Application Support ...
Страница 862: ...2 614 Volume 2 Part 2 External Interrupt Architecture ...
Страница 870: ...2 622 Volume 2 Part 2 Performance Monitoring Support ...
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Страница 941: ...3 42 Volume 3 Instruction Reference cmp illegal_operation_fault PR p1 0 PR p2 0 Interruptions Illegal Operation fault ...
Страница 1099: ...3 200 Volume 3 Instruction Reference padd Interruptions Illegal Operation fault ...
Страница 1191: ...3 292 Volume 3 Pseudo Code Functions Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 1295: ...3 396 Volume 3 Resource and Dependency Semantics ...
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Страница 1494: ...4 192 Volume 4 Base IA 32 Instruction Reference FWAIT Wait See entry for WAIT ...
Страница 1564: ...4 262 Volume 4 Base IA 32 Instruction Reference LES Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 1565: ...Volume 4 Base IA 32 Instruction Reference 4 263 LFS Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 1568: ...4 266 Volume 4 Base IA 32 Instruction Reference LGS Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 1583: ...Volume 4 Base IA 32 Instruction Reference 4 281 LSS Load Full Pointer See entry for LDS LES LFS LGS LSS ...
Страница 1647: ...Volume 4 Base IA 32 Instruction Reference 4 345 ROL ROR Rotate See entry for RCL RCR ROL ROR ...
Страница 1663: ...Volume 4 Base IA 32 Instruction Reference 4 361 SHL SHR Shift Instructions See entry for SAL SAR SHL SHR ...
Страница 1668: ...4 366 Volume 4 Base IA 32 Instruction Reference SIDT Store Interrupt Descriptor Table Register See entry for SGDT SIDT ...
Страница 1884: ...4 582 Volume 4 IA 32 SSE Instruction Reference ...
Страница 1885: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 Index ...
Страница 1886: ...Index Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
Страница 1898: ...INDEX Index 12 Index for Volumes 1 2 3 and 4 ...