Zicbom Extension

Versions

Version 1.0.0
State	ratified
Ratification date	2022-05

Version 1.0.0

State

ratified

Ratification date

2022-05

Synopsis

Cache-block management instructions

Instructions

The following instructions are affected by this extension:

cbo.clean

Cache Block Clean

cbo.flush

Cache Block Flush

cbo.inval

Cache Block Invalidate

Parameters

This extension has the following implementation options (AKA parameters):

CACHE_BLOCK_SIZE

Type
integer
Valid Values
[1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824, 2147483648, 4294967296, 8589934592, 17179869184, 34359738368, 68719476736, 137438953472, 274877906944, 549755813888, 1099511627776, 2199023255552, 4398046511104, 8796093022208, 17592186044416, 35184372088832, 70368744177664, 140737488355328, 281474976710656, 562949953421312, 1125899906842624, 2251799813685248, 4503599627370496, 9007199254740992, 18014398509481984, 36028797018963968, 72057594037927936, 144115188075855872, 288230376151711744, 576460752303423488, 1152921504606846976, 2305843009213693952, 4611686018427387904, 9223372036854775808]
Description
The observable size of a cache block, in bytes. A cache block is a naturally aligned power-of-two (NAPOT) range of memory.

Type

integer

Valid Values

[1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072, 262144, 524288, 1048576, 2097152, 4194304, 8388608, 16777216, 33554432, 67108864, 134217728, 268435456, 536870912, 1073741824, 2147483648, 4294967296, 8589934592, 17179869184, 34359738368, 68719476736, 137438953472, 274877906944, 549755813888, 1099511627776, 2199023255552, 4398046511104, 8796093022208, 17592186044416, 35184372088832, 70368744177664, 140737488355328, 281474976710656, 562949953421312, 1125899906842624, 2251799813685248, 4503599627370496, 9007199254740992, 18014398509481984, 36028797018963968, 72057594037927936, 144115188075855872, 288230376151711744, 576460752303423488, 1152921504606846976, 2305843009213693952, 4611686018427387904, 9223372036854775808]

Description

The observable size of a cache block, in bytes. A cache block is a naturally aligned power-of-two (NAPOT) range of memory.

FORCE_UPGRADE_CBO_INVAL_TO_FLUSH

Type
boolean
Valid Values
boolean
Description
When true, an implementation prohibits setting menvcfg.CBIE == `11` such that all cbo.inval instructions either trap (when menvcfg.CBIE == '00') or flush (when menvcfg.CBIE == '01'). When false, an implementation allows a true INVAL operation for cbo.inval, and thus supports the setting menvcfg.CBIE == `11`.

Type

boolean

Valid Values

boolean

Description

When true, an implementation prohibits setting menvcfg.CBIE == 11 such that all cbo.inval instructions either trap (when menvcfg.CBIE == '00') or flush (when menvcfg.CBIE == '01').

When false, an implementation allows a true INVAL operation for cbo.inval, and thus supports the setting menvcfg.CBIE == 11.