公开(公告)号：US11755333B2

公开(公告)日：2023-09-12

申请号：US17643765

申请日：2021-12-10

Applicant: Apple Inc.

Inventor： Brandon H. Dwiel ,  Andrew J. Beaumont-Smith ,  Eric J. Furbish ,  John D. Pape ,  Stephen G. Meier ,  Tyler J. Huberty

IPC: G06F9/38

CPC classification number: G06F9/3881 ,  G06F9/382 ,  G06F9/383 ,  G06F9/3877

Abstract: A prefetcher for a coprocessor is disclosed. An apparatus includes a processor and a coprocessor that are configured to execute processor and coprocessor instructions, respectively. The processor and coprocessor instructions appear together in code sequences fetched by the processor, with the coprocessor instructions being provided to the coprocessor by the processor. The apparatus further includes a coprocessor prefetcher configured to monitor a code sequence fetched by the processor and, in response to identifying a presence of coprocessor instructions in the code sequence, capture the memory addresses, generated by the processor, of operand data for coprocessor instructions. The coprocessor is further configured to issue, for a cache memory accessible to the coprocessor, prefetches for data associated with the memory addresses prior to execution of the coprocessor instructions by the coprocessor.

公开(公告)号：US20230236988A1

公开(公告)日：2023-07-27

申请号：US18189982

申请日：2023-03-24

Applicant: Apple Inc.

Inventor： John D. Pape ,  Brian R. Mestan ,  Peter G. Soderquist

IPC: G06F12/1027 ,  G06F9/455

CPC classification number: G06F12/1027 ,  G06F9/45558 ,  G06F2212/683 ,  G06F2009/45583

Abstract: Systems, apparatuses, and methods for performing efficient translation lookaside buffer (TLB) invalidation operations for splintered pages are described. When a TLB receives an invalidation request for a specified translation context, and the invalidation request maps to an entry with a relatively large page size, the TLB does not know if there are multiple translation entries stored in the TLB for smaller splintered pages of the relatively large page. The TLB tracks whether or not splintered pages for each translation context have been installed. If a TLB invalidate (TLBI) request is received, and splintered pages have not been installed, no searches are needed for splintered pages. To refresh the sticky bits, whenever a full TLB search is performed, the TLB rescans for splintered pages for other translation contexts. If no splintered pages are found, the sticky bit can be cleared and the number of full TLBI searches is reduced.

公开(公告)号：US11675710B2

公开(公告)日：2023-06-13

申请号：US17016179

申请日：2020-09-09

Applicant: Apple Inc.

Inventor： John D. Pape ,  Brian R. Mestan ,  Peter G. Soderquist

IPC: G06F12/1045 ,  G06F12/0882 ,  G06F9/455 ,  G06F12/1027

CPC classification number: G06F12/1063 ,  G06F9/45558 ,  G06F12/0882 ,  G06F12/1027 ,  G06F2009/45583 ,  G06F2212/7201

Abstract: Systems, apparatuses, and methods for limiting translation lookaside buffer (TLB) searches using active page size are described. A TLB stores virtual-to-physical address translations for a plurality of different page sizes. When the TLB receives a command to invalidate a TLB entry corresponding to a specified virtual address, the TLB performs, for the plurality of different pages sizes, multiple different lookups of the indices corresponding to the specified virtual address. In order to reduce the number of lookups that are performed, the TLB relies on a page size presence vector and an age matrix to determine which page sizes to search for and in which order. The page size presence vector indicates which page sizes may be stored for the specified virtual address. The age matrix stores a preferred search order with the most probable page size first and the least probable page size last.

公开(公告)号：US11615033B2

公开(公告)日：2023-03-28

申请号：US17016229

申请日：2020-09-09

Applicant: Apple Inc.

Inventor： John D. Pape ,  Brian R. Mestan ,  Peter G. Soderquist

IPC: G06F12/1027 ,  G06F9/455

Abstract: Systems, apparatuses, and methods for performing efficient translation lookaside buffer (TLB) invalidation operations for splintered pages are described. When a TLB receives an invalidation request for a specified translation context, and the invalidation request maps to an entry with a relatively large page size, the TLB does not know if there are multiple translation entries stored in the TLB for smaller splintered pages of the relatively large page. The TLB tracks whether or not splintered pages for each translation context have been installed. If a TLB invalidate (TLBI) request is received, and splintered pages have not been installed, no searches are needed for splintered pages. To refresh the sticky bits, whenever a full TLB search is performed, the TLB rescans for splintered pages for other translation contexts. If no splintered pages are found, the sticky bit can be cleared and the number of full TLBI searches is reduced.

公开(公告)号：US11422946B2

公开(公告)日：2022-08-23

申请号：US17008457

申请日：2020-08-31

Applicant: Apple Inc.

Inventor： John D. Pape ,  Brian R. Mestan ,  Peter G. Soderquist

IPC: G06F12/10 ,  G06F12/1027

Abstract: Systems, apparatuses, and methods for implementing translation lookaside buffer (TLB) striping to enable efficient invalidation operations are described. TLB sizes are growing in width (more features in a given page table entry) and depth (to cover larger memory footprints). A striping scheme is proposed to enable an efficient and high performance method for performing TLB maintenance operations in the face of this growth. Accordingly, a TLB stores first attribute data in a striped manner across a plurality of arrays. The striped manner allows different entries to be searched simultaneously in response to receiving an invalidation request which identifies a particular attribute of a group to be invalidated. Upon receiving an invalidation request, the TLB generates a plurality of indices with an offset between each index and walks through the plurality of arrays by incrementing each index and simultaneously checking the first attribute data in corresponding entries.

公开(公告)号：US20220075735A1

公开(公告)日：2022-03-10

申请号：US17016179

申请日：2020-09-09

Applicant: Apple Inc.

Inventor： John D. Pape ,  Brian R. Mestan ,  Peter G. Soderquist

IPC: G06F12/1045 ,  G06F12/0882 ,  G06F9/455

Abstract: Systems, apparatuses, and methods for limiting translation lookaside buffer (TLB) searches using active page size are described. A TLB stores virtual-to-physical address translations for a plurality of different page sizes. When the TLB receives a command to invalidate a TLB entry corresponding to a specified virtual address, the TLB performs, for the plurality of different pages sizes, multiple different lookups of the indices corresponding to the specified virtual address. In order to reduce the number of lookups that are performed, the TLB relies on a page size presence vector and an age matrix to determine which page sizes to search for and in which order. The page size presence vector indicates which page sizes may be stored for the specified virtual address. The age matrix stores a preferred search order with the most probable page size first and the least probable page size last.

公开(公告)号：US20220075734A1

公开(公告)日：2022-03-10

申请号：US17016229

申请日：2020-09-09

Applicant: Apple Inc.

Inventor： John D. Pape ,  Brian R. Mestan ,  Peter G. Soderquist

IPC: G06F12/1027 ,  G06F9/455

Abstract: Systems, apparatuses, and methods for performing efficient translation lookaside buffer (TLB) invalidation operations for splintered pages are described. When a TLB receives an invalidation request for a specified translation context, and the invalidation request maps to an entry with a relatively large page size, the TLB does not know if there are multiple translation entries stored in the TLB for smaller splintered pages of the relatively large page. The TLB tracks whether or not splintered pages for each translation context have been installed. If a TLB invalidate (TLBI) request is received, and splintered pages have not been installed, no searches are needed for splintered pages. To refresh the sticky bits, whenever a full TLB search is performed, the TLB rescans for splintered pages for other translation contexts. If no splintered pages are found, the sticky bit can be cleared and the number of full TLBI searches is reduced.