Changelog:
v17:
        - Merged with 5.15-rc1 as requested by Catalin Marinas
        - Added Tested-by: Pingfan Liu <pi...@redhat.com>
v16:
        - Merged with 5.14-rc4
v15:
        - Changed trans_pgd_copy_el2_vectors() to use vector table that
          only shared by kexec and hibernate. This way sync does not have
          dangling branch that was recently introduced. (Reported by Marc
          Zyngier)
        - Renamed is_hyp_callable() to is_hyp_nvhe() as requested by Marc
          Zyngier
        - Clean-ups, comment fixes.
        - Sync with upstream 368094df48e680fa51cedb68537408cfa64b788e
v14:
        - Fixed a bug in "arm64: hyp-stub: Move elx_sync into the vectors"
          that was noticed by Marc Zyngier
        - Merged with upstream
v13:
        - Fixed a hang on ThunderX2, thank you Pingfan Liu for reporting
          the problem. In relocation function we need civac not ivac, we
          need to clean data in addition to invalidating it.
          Since I was using ThunderX2 machine I also measured the new
          performance data on this large ARM64 server. The MMU improves
          kexec relocation 190 times on this machine! (see below for
          raw data). Saves 7.5s during CentOS kexec reboot.
v12:
        - A major change compared to previous version. Instead of using
          contiguous VA range a copy of linear map is now used to perform
          copying of segments during relocation as it was agreed in the
          discussion of version 11 of this project.
        - In addition to using linear map, I also took several ideas from
          James Morse to better organize the kexec relocation:
                1. skip relocation function entirely if that is not needed
                2. remove the PoC flushing function since it is not needed
                   anymore with MMU enabled.
v11:
        - Fixed missing KEXEC_CORE dependency for trans_pgd.c
        - Removed useless "if(rc) return rc" statement (thank you Tyler Hicks)
        - Another 12 patches were accepted into maintainer's get.
          Re-based patches against:
          https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
          Branch: for-next/kexec
v10:
        - Addressed a lot of comments form James Morse and from  Marc Zyngier
        - Added review-by's
        - Synchronized with mainline

v9:     - 9 patches from previous series landed in upstream, so now series
          is smaller
        - Added two patches from James Morse to address idmap issues for 
machines
          with high physical addresses.
        - Addressed comments from Selin Dag about compiling issues. He also 
tested
          my series and got similar performance results: ~60 ms instead of ~580 
ms
          with an initramfs size of ~120MB.
v8:
        - Synced with mainline to keep series up-to-date
v7:
        -- Addressed comments from James Morse
        - arm64: hibernate: pass the allocated pgdp to ttbr0
          Removed "Fixes" tag, and added Added Reviewed-by: James Morse
        - arm64: hibernate: check pgd table allocation
          Sent out as a standalone patch so it can be sent to stable
          Series applies on mainline + this patch
        - arm64: hibernate: add trans_pgd public functions
          Remove second allocation of tmp_pg_dir in swsusp_arch_resume
          Added Reviewed-by: James Morse <james.mo...@arm.com>
        - arm64: kexec: move relocation function setup and clean up
          Fixed typo in commit log
          Changed kern_reloc to phys_addr_t types.
          Added explanation why kern_reloc is needed.
          Split into four patches:
          arm64: kexec: make dtb_mem always enabled
          arm64: kexec: remove unnecessary debug prints
          arm64: kexec: call kexec_image_info only once
          arm64: kexec: move relocation function setup
        - arm64: kexec: add expandable argument to relocation function
          Changed types of new arguments from unsigned long to phys_addr_t.
          Changed offset prefix to KEXEC_*
          Split into four patches:
          arm64: kexec: cpu_soft_restart change argument types
          arm64: kexec: arm64_relocate_new_kernel clean-ups
          arm64: kexec: arm64_relocate_new_kernel don't use x0 as temp
          arm64: kexec: add expandable argument to relocation function
        - arm64: kexec: configure trans_pgd page table for kexec
          Added invalid entries into EL2 vector table
          Removed KEXEC_EL2_VECTOR_TABLE_SIZE and KEXEC_EL2_VECTOR_TABLE_OFFSET
          Copy relocation functions and table into separate pages
          Changed types in kern_reloc_arg.
          Split into three patches:
          arm64: kexec: offset for relocation function
          arm64: kexec: kexec EL2 vectors
          arm64: kexec: configure trans_pgd page table for kexec
        - arm64: kexec: enable MMU during kexec relocation
          Split into two patches:
          arm64: kexec: enable MMU during kexec relocation
          arm64: kexec: remove head from relocation argument
v6:
        - Sync with mainline tip
        - Added Acked's from Dave Young
v5:
        - Addressed comments from Matthias Brugger: added review-by's, improved
          comments, and made cleanups to swsusp_arch_resume() in addition to
          create_safe_exec_page().
        - Synced with mainline tip.
v4:
        - Addressed comments from James Morse.
        - Split "check pgd table allocation" into two patches, and moved to
          the beginning of series  for simpler backport of the fixes.
          Added "Fixes:" tags to commit logs.
        - Changed "arm64, hibernate:" to "arm64: hibernate:"
        - Added Reviewed-by's
        - Moved "add PUD_SECT_RDONLY" earlier in series to be with other
          clean-ups
        - Added "Derived from:" to arch/arm64/mm/trans_pgd.c
        - Removed "flags" from trans_info
        - Changed .trans_alloc_page assumption to return zeroed page.
        - Simplify changes to trans_pgd_map_page(), by keeping the old
          code.
        - Simplify changes to trans_pgd_create_copy, by keeping the old
          code.
        - Removed: "add trans_pgd_create_empty"
        - replace init_mm with NULL, and keep using non "__" version of
          populate functions.
v3:
        - Split changes to create_safe_exec_page() into several patches for
          easier review as request by Mark Rutland. This is why this series
          has 3 more patches.
        - Renamed trans_table to tans_pgd as agreed with Mark. The header
          comment in trans_pgd.c explains that trans stands for
          transitional page tables. Meaning they are used in transition
          between two kernels.
v2:
        - Fixed hibernate bug reported by James Morse
        - Addressed comments from James Morse:
          * More incremental changes to trans_table
          * Removed TRANS_FORCEMAP
          * Added kexec reboot data for image with 380M in size.

Enable MMU during kexec relocation in order to improve reboot performance.

If kexec functionality is used for a fast system update, with a minimal
downtime, the relocation of kernel + initramfs takes a significant portion
of reboot.

The reason for slow relocation is because it is done without MMU, and thus
not benefiting from D-Cache.

Performance data
----------------

Cavium ThunderX2:
Kernel Image size: 38M Iniramfs size: 46M Total relocation size: 84M
MMU-disabled:
relocation      7.489539915s
MMU-enabled:
relocation      0.03946095s

Relocation performance is improved 190 times.

Broadcom Stingray:
For this experiment, the size of kernel plus initramfs is small, only 25M.
If initramfs was larger, than the improvements would be greater, as time
spent in relocation is proportional to the size of relocation.

MMU-disabled::
kernel shutdown 0.022131328s
relocation      0.440510736s
kernel startup  0.294706768s

Relocation was taking: 58.2% of reboot time

MMU-enabled:
kernel shutdown 0.032066576s
relocation      0.022158152s
kernel startup  0.296055880s

Now: Relocation takes 6.3% of reboot time

Total reboot is x2.16 times faster.

With bigger userland (fitImage 380M), the reboot time is improved by 3.57s,
and is reduced from 3.9s down to 0.33s

Previous approaches and discussions
-----------------------------------
v16: 
https://lore.kernel.org/lkml/20210802215408.804942-1-pasha.tatas...@soleen.com
v15: 
https://lore.kernel.org/lkml/20210609004419.936873-1-pasha.tatas...@soleen.com
v14: 
https://lore.kernel.org/lkml/20210527150526.271941-1-pasha.tatas...@soleen.com
v13: 
https://lore.kernel.org/lkml/20210408040537.2703241-1-pasha.tatas...@soleen.com
v12: 
https://lore.kernel.org/lkml/20210303002230.1083176-1-pasha.tatas...@soleen.com
v11: 
https://lore.kernel.org/lkml/20210127172706.617195-1-pasha.tatas...@soleen.com
v10: 
https://lore.kernel.org/linux-arm-kernel/20210125191923.1060122-1-pasha.tatas...@soleen.com
v9: 
https://lore.kernel.org/lkml/20200326032420.27220-1-pasha.tatas...@soleen.com
v8: 
https://lore.kernel.org/lkml/20191204155938.2279686-1-pasha.tatas...@soleen.com
v7: 
https://lore.kernel.org/lkml/20191016200034.1342308-1-pasha.tatas...@soleen.com
v6: 
https://lore.kernel.org/lkml/20191004185234.31471-1-pasha.tatas...@soleen.com
v5: 
https://lore.kernel.org/lkml/20190923203427.294286-1-pasha.tatas...@soleen.com
v4: 
https://lore.kernel.org/lkml/20190909181221.309510-1-pasha.tatas...@soleen.com
v3: 
https://lore.kernel.org/lkml/20190821183204.23576-1-pasha.tatas...@soleen.com
v2: 
https://lore.kernel.org/lkml/20190817024629.26611-1-pasha.tatas...@soleen.com
v1: 
https://lore.kernel.org/lkml/20190801152439.11363-1-pasha.tatas...@soleen.com

Pasha Tatashin (15):
  arm64: kernel: add helper for booted at EL2 and not VHE
  arm64: trans_pgd: hibernate: Add trans_pgd_copy_el2_vectors
  arm64: hibernate: abstract ttrb0 setup function
  arm64: kexec: flush image and lists during kexec load time
  arm64: kexec: skip relocation code for inplace kexec
  arm64: kexec: Use dcache ops macros instead of open-coding
  arm64: kexec: pass kimage as the only argument to relocation function
  arm64: kexec: configure EL2 vectors for kexec
  arm64: kexec: relocate in EL1 mode
  arm64: kexec: use ld script for relocation function
  arm64: kexec: install a copy of the linear-map
  arm64: kexec: keep MMU enabled during kexec relocation
  arm64: kexec: remove the pre-kexec PoC maintenance
  arm64: kexec: remove cpu-reset.h
  arm64: trans_pgd: remove trans_pgd_map_page()

 arch/arm64/Kconfig                   |   2 +-
 arch/arm64/include/asm/assembler.h   |  49 ++++++--
 arch/arm64/include/asm/kexec.h       |  12 ++
 arch/arm64/include/asm/mmu_context.h |  24 ++++
 arch/arm64/include/asm/sections.h    |   1 +
 arch/arm64/include/asm/trans_pgd.h   |  14 ++-
 arch/arm64/include/asm/virt.h        |   7 ++
 arch/arm64/kernel/asm-offsets.c      |  11 ++
 arch/arm64/kernel/cpu-reset.S        |   7 +-
 arch/arm64/kernel/cpu-reset.h        |  32 -----
 arch/arm64/kernel/hibernate-asm.S    |  72 -----------
 arch/arm64/kernel/hibernate.c        |  49 ++------
 arch/arm64/kernel/machine_kexec.c    | 177 ++++++++++++++-------------
 arch/arm64/kernel/relocate_kernel.S  |  70 +++++------
 arch/arm64/kernel/sdei.c             |   2 +-
 arch/arm64/kernel/vmlinux.lds.S      |  19 +++
 arch/arm64/mm/Makefile               |   1 +
 arch/arm64/mm/trans_pgd-asm.S        |  65 ++++++++++
 arch/arm64/mm/trans_pgd.c            |  84 ++++---------
 19 files changed, 358 insertions(+), 340 deletions(-)
 delete mode 100644 arch/arm64/kernel/cpu-reset.h
 create mode 100644 arch/arm64/mm/trans_pgd-asm.S


base-commit: ff1ffd71d5f0612cf194f5705c671d6b64bf5f91
-- 
2.25.1


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