[RFC PATCH 00/13] ARC: handle the lack of ZOL support

[Vineet Gupta]

Thx for doing this. I think the series mixes a few things not related to 
ZOL removal - the changelog for removal of -Os specific code seems 
incorrect etc.
Let me repost with slight more cleanups.

-Vineet

On 2/22/22 06:14, Sergey Matyukevich wrote:
> From: Sergey Matyukevich <sergey.matyukevich at synopsys.com>
>
> Hi Vineet and all,
>
> This patch series continues to prepare arch/arc for the upcoming ARCv3
> support. ARCv3 does not support zero-overhead-loop (ZOL). So this patch
> series provides a set of changes that make ZOL support optional.
>
> The patch series is based on top of Linux 5.17-rc5. It has been tested
> with enabled CONFIG_ARC_LACKS_ZOL option on ARCv2 HSDK hardware as well
> as on nSIM simulator for ARCv2.
>
> I fixed typos, updated Vineet's email address, and slightly modified
> several commit messages. Otherwise this patch series is the first chunk
> of ARCv3 bring-up changes by Vineet, available at Synopsys github: see
> github.com/foss-for-synopsys-dwc-arc-processors/linux
>
> Regards,
> Sergey
>
> Vineet Gupta (13):
>    ARC: uaccess: elide unaliged handling if hardware supports
>    ARC: Kconfig: introduce option to disable ZOL
>    ARC: uaccess: drop CC_OPTIMIZE_FOR_SIZE
>    ARC: uaccess: elide ZOL, use double load/stores
>    ARCv2: memset: don't prefetch for len == 0 which happens a lot
>    ARCv2: memset: elide unaligned handling if hardware supports
>    ARCv2: memset: rewrite using double load/stores
>    ARC: string: use generic C code if no ZOL support
>    ARC: delay: elide ZOL
>    ARC: checksum: elide ZOL
>    ARC: head: elide ZOL
>    ARC: build: inhibit ZOL generation by compiler
>    ARC: pt_regs: handle the case when ZOL is not supported
>
>   arch/arc/Kconfig                           |  10 ++
>   arch/arc/Makefile                          |   3 +
>   arch/arc/include/asm/asm-macro-dbnz-emul.h |  12 ++
>   arch/arc/include/asm/asm-macro-dbnz.h      |   8 ++
>   arch/arc/include/asm/asm-macro-ll64-emul.h |  31 +++++
>   arch/arc/include/asm/asm-macro-ll64.h      |  20 +++
>   arch/arc/include/asm/assembler.h           |  41 ++++++
>   arch/arc/include/asm/checksum.h            |  58 +++++++-
>   arch/arc/include/asm/delay.h               |  16 +++
>   arch/arc/include/asm/entry-arcv2.h         |   4 +
>   arch/arc/include/asm/entry.h               |   2 +
>   arch/arc/include/asm/ptrace.h              |   4 +-
>   arch/arc/include/asm/string.h              |  15 ++-
>   arch/arc/include/asm/uaccess.h             |  29 ++--
>   arch/arc/kernel/arcksyms.c                 |   2 +
>   arch/arc/kernel/asm-offsets.c              |   2 +
>   arch/arc/kernel/disasm.c                   |   2 +
>   arch/arc/kernel/head.S                     |   8 +-
>   arch/arc/kernel/intc-arcv2.c               |   2 +
>   arch/arc/kernel/kgdb.c                     |   4 +
>   arch/arc/kernel/process.c                  |   2 +
>   arch/arc/kernel/ptrace.c                   |  12 ++
>   arch/arc/kernel/signal.c                   |   8 ++
>   arch/arc/kernel/troubleshoot.c             |   3 +
>   arch/arc/kernel/unaligned.c                |   2 +
>   arch/arc/kernel/vmlinux.lds.S              |   2 +-
>   arch/arc/lib/Makefile                      |   6 +
>   arch/arc/lib/memset-archs.S                | 147 +++++++++------------
>   arch/arc/lib/uaccess.S                     | 144 ++++++++++++++++++++
>   arch/arc/mm/extable.c                      |  11 --
>   30 files changed, 493 insertions(+), 117 deletions(-)
>   create mode 100644 arch/arc/include/asm/asm-macro-dbnz-emul.h
>   create mode 100644 arch/arc/include/asm/asm-macro-dbnz.h
>   create mode 100644 arch/arc/include/asm/asm-macro-ll64-emul.h
>   create mode 100644 arch/arc/include/asm/asm-macro-ll64.h
>   create mode 100644 arch/arc/include/asm/assembler.h
>   create mode 100644 arch/arc/lib/uaccess.S
>