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mem: Add TLB invalidation flags to the Request object

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Some ISAs implement TLB invalidation across multiple cores (TLB
shootdown) by broadcasting invalidation messages to every PE in a
target shareability domain.

These messages originate by specific instructions and can be
cathegorized in two macro groups

1) TLB Invalidation instructions: generating the invalidation
request

Example:
* Arm: TLBI instruction [1]
* AMD64: INVLPGB instruction [2]

2) TLB Invalidation sync instructions: serialization point, ensuring
completion of outstanding invalidation requests

Example:
* Arm: DSB instruction [1]
* AMD64: TLBSYNC instruction [2]

This patch is introducing TLBI and SYNC operations in the memory
subsystem by adding the following Request flags:

* TLBI (1)
* TLBI_SYNC (2)

JIRA: https://gem5.atlassian.net/browse/GEM5-1097

[1]: https://developer.arm.com/documentation/ddi0487/gb/
[2]: https://www.amd.com/system/files/TechDocs/24594.pdf

Change-Id: Ib5b025d0f6bc0edaf4f11a66593947a72ba32b8f
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/56596
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
This commit is contained in:
Samuel Stark
2021-10-25 16:43:00 +01:00
committed by Giacomo Travaglini
parent a00f6d67d4
commit 77263615db
1 changed files with 13 additions and 1 deletions
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14
src/mem/request.hh
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@@ -1,5 +1,5 @@
/*
* Copyright (c) 2012-2013,2017-2020 ARM Limited
* Copyright (c) 2012-2013,2017-2021 Arm Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
@@ -237,6 +237,12 @@ class Request
// This separation is necessary to ensure the disjoint components
// of the system work correctly together.
/** The Request is a TLB shootdown */
TLBI = 0x0000100000000000,
/** The Request is a TLB shootdown sync */
TLBI_SYNC = 0x0000200000000000,
/**
* These flags are *not* cleared when a Request object is
* reused (assigned a new address).
@@ -249,6 +255,8 @@ class Request
static const FlagsType HTM_CMD = HTM_START | HTM_COMMIT |
HTM_CANCEL | HTM_ABORT;
static const FlagsType TLBI_CMD = TLBI | TLBI_SYNC;
/** Requestor Ids that are statically allocated
* @{*/
enum : RequestorID
@@ -975,6 +983,10 @@ class Request
isHTMCancel() || isHTMAbort());
}
bool isTlbi() const { return _flags.isSet(TLBI); }
bool isTlbiSync() const { return _flags.isSet(TLBI_SYNC); }
bool isTlbiCmd() const { return isTlbi() || isTlbiSync(); }
bool
isAtomic() const
{