Intel ITANIUM ARCHITECTURE - SOFTWARE DEVELOPERS VOLUME 3 REV 2.3, Manual

Page: 628 / 1898

2:380 Volume 2, Part 1: Processor Abstraction Layer
PAL_CACHE_READ
PAL_CACHE_READ – Read Values from the Processor Cache (259)
Purpose:
Reads the data and tag of a processor-controlled cache line for diagnostic testing.
Calling Conv:
Stacked Registers
Mode:
Physical
Buffer:
Not dependent
Arguments:
Returns:
Status:
Description:
A value is read from the specified cache line, if present. This procedure allows reading
cache data, tag, protection, or status bits.
The line_id argument is an 8-byte quantity in the following format:
• cache_type
–
Unsigned 8-bit integer denoting whether to read from instruction (1)
or data/unified (2) cache. All other values are reserved.
• level
–
Unsigned 8-bit integer specifying which cache within the cache hierarchy to
read. This value must be in the range from 0 up to one less than the cache_levels
return value from PAL_CACHE_SUMMARY.
• way
–
Unsigned 8-bit integer denoting within which cache way to read. If the cache
is direct-mapped this argument is ignored.
• part
–
Unsigned 8-bit integer denoting which portion of the specified cache line to
read:
Argument Description
index Index of PAL_CACHE_READ within the list of PAL procedures.
line_id 8-byte formatted value describing where in the cache to read the data.
address 64-bit 8-byte aligned physical address from which to read the data. The address must be an
implemented physical address on the processor model with bit 63 set to zero.
Reserved 0
Return Value Description
status Return status of the PAL_CACHE_READ procedure.
data Right-justified value returned from the cache line.
length The number of bits returned in data .
mesi The status of the cache line.
Status Value Description
1 The word at address was found in the cache, but the line was invalid.
0 Call completed without error.
-1 Unimplemented procedure
-2 Invalid argument
-3 Call completed with error.
-5 The word at address was not found in the cache.
-7 The operation requested is not supported for this cache_type and level.
Figure 11-8. Layout of line_id Return Value
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
part way level cache_type
63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 32
reserved