Register Table Processing¶
Internal infrastructure to define how registers should be updated based on rules and actions. This can be used to define tables with multiple entries (one per register) that will be walked over at some point in time to apply the values to the registers that have matching rules.
Internal API¶
-
struct xe_rtp_action¶
action to take for any matching rule
Definition:
struct xe_rtp_action {
struct xe_reg reg;
u32 clr_bits;
u32 set_bits;
#define XE_RTP_NOCHECK .read_mask = 0;
u32 read_mask;
#define XE_RTP_ACTION_FLAG_ENGINE_BASE BIT(0);
u8 flags;
};
Members
reg
Register
clr_bits
bits to clear when updating register. It’s always a superset of bits being modified
set_bits
bits to set when updating register
read_mask
mask for bits to consider when reading value back
flags
flags to apply on rule evaluation or action
Description
This struct records what action should be taken in a register that has a matching rule. Example of actions: set/clear bits.
-
XE_RTP_RULE_PLATFORM¶
XE_RTP_RULE_PLATFORM (plat_)
Create rule matching platform
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XE_RTP_RULE_SUBPLATFORM¶
XE_RTP_RULE_SUBPLATFORM (plat_, sub_)
Create rule matching platform and sub-platform
Parameters
plat_
platform to match
sub_
sub-platform to match
Description
Refer to XE_RTP_RULES()
for expected usage.
-
XE_RTP_RULE_GRAPHICS_STEP¶
XE_RTP_RULE_GRAPHICS_STEP (start_, end_)
Create rule matching graphics stepping
Parameters
start_
First stepping matching the rule
end_
First stepping that does not match the rule
Description
Note that the range matching this rule is [ start_, end_ ), i.e. inclusive on the left, exclusive on the right.
Refer to XE_RTP_RULES()
for expected usage.
-
XE_RTP_RULE_MEDIA_STEP¶
XE_RTP_RULE_MEDIA_STEP (start_, end_)
Create rule matching media stepping
Parameters
start_
First stepping matching the rule
end_
First stepping that does not match the rule
Description
Note that the range matching this rule is [ start_, end_ ), i.e. inclusive on the left, exclusive on the right.
Refer to XE_RTP_RULES()
for expected usage.
-
XE_RTP_RULE_ENGINE_CLASS¶
XE_RTP_RULE_ENGINE_CLASS (cls_)
Create rule matching an engine class
-
XE_RTP_RULE_FUNC¶
XE_RTP_RULE_FUNC (func__)
Create rule using callback function for match
Parameters
func__
Function to call to decide if rule matches
Description
This allows more complex checks to be performed. The XE_RTP
infrastructure will simply call the function func_ passed to decide if this
rule matches the device.
Refer to XE_RTP_RULES()
for expected usage.
-
XE_RTP_RULE_GRAPHICS_VERSION¶
XE_RTP_RULE_GRAPHICS_VERSION (ver__)
Create rule matching graphics version
Parameters
ver__
Graphics IP version to match
Description
Refer to XE_RTP_RULES()
for expected usage.
-
XE_RTP_RULE_GRAPHICS_VERSION_RANGE¶
XE_RTP_RULE_GRAPHICS_VERSION_RANGE (ver_start__, ver_end__)
Create rule matching a range of graphics version
Parameters
ver_start__
First graphics IP version to match
ver_end__
Last graphics IP version to match
Description
Note that the range matching this rule is [ ver_start__, ver_end__ ], i.e. inclusive on boths sides
Refer to XE_RTP_RULES()
for expected usage.
-
XE_RTP_RULE_MEDIA_VERSION¶
XE_RTP_RULE_MEDIA_VERSION (ver__)
Create rule matching media version
Parameters
ver__
Graphics IP version to match
Description
Refer to XE_RTP_RULES()
for expected usage.
-
XE_RTP_RULE_MEDIA_VERSION_RANGE¶
XE_RTP_RULE_MEDIA_VERSION_RANGE (ver_start__, ver_end__)
Create rule matching a range of media version
Parameters
ver_start__
First media IP version to match
ver_end__
Last media IP version to match
Description
Note that the range matching this rule is [ ver_start__, ver_end__ ], i.e. inclusive on boths sides
Refer to XE_RTP_RULES()
for expected usage.
-
XE_RTP_RULE_IS_INTEGRATED¶
XE_RTP_RULE_IS_INTEGRATED ()
Create a rule matching integrated graphics devices
-
XE_RTP_RULE_IS_DISCRETE¶
XE_RTP_RULE_IS_DISCRETE ()
Create a rule matching discrete graphics devices
-
XE_RTP_ACTION_WR¶
XE_RTP_ACTION_WR (reg_, val_, ...)
Helper to write a value to the register, overriding all the bits
Parameters
reg_
Register
val_
Value to set
...
Additional fields to override in the
struct xe_rtp_action
entry
Description
The correspondent notation in bspec is:
REGNAME = VALUE
-
XE_RTP_ACTION_SET¶
XE_RTP_ACTION_SET (reg_, val_, ...)
Set bits from val_ in the register.
Parameters
reg_
Register
val_
Bits to set in the register
...
Additional fields to override in the
struct xe_rtp_action
entry
Description
For masked registers this translates to a single write, while for other registers it’s a RMW. The correspondent bspec notation is (example for bits 2 and 5, but could be any):
REGNAME[2] = 1 REGNAME[5] = 1
-
XE_RTP_ACTION_CLR¶
XE_RTP_ACTION_CLR (reg_, val_, ...)
Clear bits from val_ in the register.
Parameters
reg_
Register
val_
Bits to clear in the register
...
Additional fields to override in the
struct xe_rtp_action
entry
Description
For masked registers this translates to a single write, while for other registers it’s a RMW. The correspondent bspec notation is (example for bits 2 and 5, but could be any):
REGNAME[2] = 0 REGNAME[5] = 0
-
XE_RTP_ACTION_FIELD_SET¶
XE_RTP_ACTION_FIELD_SET (reg_, mask_bits_, val_, ...)
Set a bit range
Parameters
reg_
Register
mask_bits_
Mask of bits to be changed in the register, forming a field
val_
Value to set in the field denoted by mask_bits_
...
Additional fields to override in the
struct xe_rtp_action
entry
Description
For masked registers this translates to a single write, while for other registers it’s a RMW. The correspondent bspec notation is:
REGNAME[<end>:<start>] = VALUE
-
XE_RTP_ACTION_WHITELIST¶
XE_RTP_ACTION_WHITELIST (reg_, val_, ...)
Add register to userspace whitelist
Parameters
reg_
Register
val_
Whitelist-specific flags to set
...
Additional fields to override in the
struct xe_rtp_action
entry
Description
Add a register to the whitelist, allowing userspace to modify the ster with regular user privileges.
-
XE_RTP_NAME¶
XE_RTP_NAME (s_)
Helper to set the name in xe_rtp_entry
Parameters
s_
Name describing this rule, often a HW-specific number
Description
TODO: maybe move this behind a debug config?
-
XE_RTP_ENTRY_FLAG¶
XE_RTP_ENTRY_FLAG (...)
Helper to add multiple flags to a struct xe_rtp_entry_sr
Parameters
...
Entry flags, without the
XE_RTP_ENTRY_FLAG_
prefix
Description
Helper to automatically add a XE_RTP_ENTRY_FLAG_
prefix to the flags
when defining struct xe_rtp_entry entries. Example:
const struct xe_rtp_entry_sr wa_entries[] = {
...
{ XE_RTP_NAME("test-entry"),
...
XE_RTP_ENTRY_FLAG(FOREACH_ENGINE),
...
},
...
};
-
XE_RTP_ACTION_FLAG¶
XE_RTP_ACTION_FLAG (...)
Helper to add multiple flags to a
struct xe_rtp_action
Parameters
...
Action flags, without the
XE_RTP_ACTION_FLAG_
prefix
Description
Helper to automatically add a XE_RTP_ACTION_FLAG_
prefix to the flags
when defining struct xe_rtp_action
entries. Example:
const struct xe_rtp_entry_sr wa_entries[] = {
...
{ XE_RTP_NAME("test-entry"),
...
XE_RTP_ACTION_SET(..., XE_RTP_ACTION_FLAG(FOREACH_ENGINE)),
...
},
...
};
-
XE_RTP_RULES¶
XE_RTP_RULES (...)
Helper to set multiple rules to a struct xe_rtp_entry_sr entry
Parameters
...
Rules
Description
At least one rule is needed and up to 4 are supported. Multiple rules are AND’ed together, i.e. all the rules must evaluate to true for the entry to be processed. See XE_RTP_MATCH_* for the possible match rules. Example:
const struct xe_rtp_entry_sr wa_entries[] = {
...
{ XE_RTP_NAME("test-entry"),
XE_RTP_RULES(SUBPLATFORM(DG2, G10), GRAPHICS_STEP(A0, B0)),
...
},
...
};
-
XE_RTP_ACTIONS¶
XE_RTP_ACTIONS (...)
Helper to set multiple actions to a struct xe_rtp_entry_sr
Parameters
...
Actions to be taken
Description
At least one action is needed and up to 4 are supported. See XE_RTP_ACTION_* for the possible actions. Example:
const struct xe_rtp_entry_sr wa_entries[] = {
...
{ XE_RTP_NAME("test-entry"),
XE_RTP_RULES(...),
XE_RTP_ACTIONS(SET(..), SET(...), CLR(...)),
...
},
...
};
-
bool xe_rtp_match_even_instance(const struct xe_gt *gt, const struct xe_hw_engine *hwe)¶
Match if engine instance is even
Parameters
const struct xe_gt *gt
GT structure
const struct xe_hw_engine *hwe
Engine instance
Return
true if engine instance is even, false otherwise
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void xe_rtp_process_ctx_enable_active_tracking(struct xe_rtp_process_ctx *ctx, unsigned long *active_entries, size_t n_entries)¶
Enable tracking of active entries
Parameters
struct xe_rtp_process_ctx *ctx
The context for processing the table
unsigned long *active_entries
bitmap to store the active entries
size_t n_entries
number of entries to be processed
Description
Set additional metadata to track what entries are considered “active”, i.e. their rules match the condition. Bits are never cleared: entries with matching rules set the corresponding bit in the bitmap.
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void xe_rtp_process_to_sr(struct xe_rtp_process_ctx *ctx, const struct xe_rtp_entry_sr *entries, struct xe_reg_sr *sr)¶
Process all rtp entries, adding the matching ones to the save-restore argument.
Parameters
struct xe_rtp_process_ctx *ctx
The context for processing the table, with one of device, gt or hwe
const struct xe_rtp_entry_sr *entries
Table with RTP definitions
struct xe_reg_sr *sr
Save-restore struct where matching rules execute the action. This can be viewed as the “coalesced view” of multiple the tables. The bits for each register set are expected not to collide with previously added entries
Description
Walk the table pointed by entries (with an empty sentinel) and add all entries with matching rules to sr. If hwe is not NULL, its mmio_base is used to calculate the right register offset
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void xe_rtp_process(struct xe_rtp_process_ctx *ctx, const struct xe_rtp_entry *entries)¶
Process all rtp entries, without running any action
Parameters
struct xe_rtp_process_ctx *ctx
The context for processing the table, with one of device, gt or hwe
const struct xe_rtp_entry *entries
Table with RTP definitions
Description
Walk the table pointed by entries (with an empty sentinel), executing the
rules. A few differences from xe_rtp_process_to_sr()
:
There is no action associated with each entry since this uses struct xe_rtp_entry. Its main use is for marking active workarounds via
xe_rtp_process_ctx_enable_active_tracking()
.There is support for OR operations by having entries with no name.