Volume 2, Part 1: Addressing and Protection
2:65
For multiprocessor systems, atomic updates of long-format VHPT entries may be
ensured by software as follows:
• Before making multiple non-atomic updates to a VHPT entry in memory, software is
required to set its ti bit to one.
• After making multiple non-atomic updates to a VHPT entry in memory, software
may clear its ti bit to zero to re-enable tag matches.
The updates to the VHPT entry in memory must be constrained to be observable only
after the store that sets the ti bit to one is observable. This can be accomplished with a
mf
instruction, or by performing the updates to the VHPT entry with release stores.
Similarly, the clearing of the ti bit must be constrained to be observable only after all of
the updates to the VHPT entry are observable. This can be accomplished with a
mf
instruction, or by performing the clear of the ti bit with a release store.
4.1.6
VHPT Hashing
The processor provides two methods for software to determine a VHPT entry’s address:
the Translation Hash (
thash
) instruction, and the Interruption Hash Address (IHA)
register defined on
. The virtual address of the VHPT entry is placed in the
IHA register when a VHPT Translation or TLB fault is delivered. In the long format, IHA
can be used as a starting address to scan additional collision chains (associativities)
defined by the operating system or to perform a search in software. The
thash
instruction is used to generate a VHPT entry’s address outside of interruption handlers
and provides the same hash function that is used to calculate IHA.
thash
produces a VHPT entry’s address for a given virtual address and region identifier,
depending on the setting of the PTA.vf bit. When PTA.vf=0,
thash
returns the
region-based short-format index as defined in
“Region-based VHPT Short-format Index”
. When PTA.vf=1,
thash
returns the long-format hash as defined in
“Long-format VHPT Hash” on page 2:66
. The
ttag
instruction is only useful for
long-format hashing, and generates a 64-bit ti/tag identifier that the processor’s VHPT
walker will check when it looks up a given virtual address and region identifier. Software
should use the
ttag
instruction, and either the
thash
instruction or the IHA register
when forming translation tags and hash addresses for the long-format VHPT. These
resources encapsulate the implementation-specific long-format hashing functionality
and improve performance.
4.1.6.1
Region-based VHPT Short-format Index
In the region-based short format, the linear page table for each region resides in the
referenced region itself. As a result, the short-format VHPT consists of separate
per-region page tables, which are anchored in each region by PTA{60:15}. For regions
Figure 4-13. VHPT Not-present Long Format
offset
63
32 31
8
7
2 1 0
+0
ig
0
+8
rv
key
ps
rv
+16
ti
tag
+24
ig
Содержание ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3
Страница 1: ......
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 ...
Страница 230: ......
Страница 248: ...236 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
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 ...
Страница 891: ......
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 ...
Страница 1296: ......
Страница 1302: ...402 Intel Itanium Architecture Software Developer s Manual Rev 2 3 ...
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 ...