linux-stable.git/arch/powerpc/kernel/setup_64.c, branch v5.18.2

Merge branch 'topic/ppc-kvm' into next

2022-03-28T10:11:24+00:00

Merge some more commits from our KVM topic branch. In particular this
brings in some commits that depend on a new capability that was merged
via the KVM tree for v5.18.

powerpc: Move C prototypes out of asm-prototypes.h

2022-03-08T11:06:25+00:00

We originally added asm-prototypes.h in commit 42f5b4cacd78 ("powerpc:
Introduce asm-prototypes.h"). It's purpose was for prototypes of C
functions that are only called from asm, in order to fix sparse
warnings about missing prototypes.

A few months later Nick added a different use case in
commit 4efca4ed05cb ("kbuild: modversions for EXPORT_SYMBOL() for asm")
for C prototypes for exported asm functions. This is basically the
inverse of our original usage.

Since then we've added various prototypes to asm-prototypes.h for both
reasons, meaning we now need to unstitch it all.

Dispatch prototypes of C functions into relevant headers and keep
only the prototypes for functions defined in assembly.

For the time being, leave prom_init() there because moving it
into asm/prom.h or asm/setup.h conflicts with
drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowrom.o
This will be fixed later by untaggling asm/pci.h and asm/prom.h
or by renaming the function in shadowrom.c

Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/62d46904eca74042097acf4cb12c175e3067f3d1.1646413435.git.christophe.leroy@csgroup.eu

KVM: PPC: Book3S PR: Disable SCV when AIL could be disabled

2022-03-08T02:13:58+00:00

PR KVM does not support running with AIL enabled, and SCV does is not
supported with AIL disabled. Fix this by ensuring the SCV facility is
disabled with FSCR while a CPU could be running with AIL=0.

The PowerNV host supports disabling AIL on a per-CPU basis, so SCV just
needs to be disabled when a vCPU is being run.

The pSeries machine can only switch AIL on a system-wide basis, so it
must disable SCV support at boot if the configuration can potentially
run a PR KVM guest.

Also ensure a the FSCR[SCV] bit can not be enabled when emulating
mtFSCR for the guest.

SCV is not emulated for the PR guest at the moment, this just fixes the
host crashes.

Alternatives considered and rejected:
- SCV support can not be disabled by PR KVM after boot, because it is
  advertised to userspace with HWCAP.
- AIL can not be disabled on a per-CPU basis. At least when running on
  pseries it is a per-LPAR setting.
- Support for real-mode SCV vectors will not be added because they are
  at 0x17000 so making such a large fixed head space causes immediate
  value limits to be exceeded, requiring a lot rework and more code.
- Disabling SCV for any PR KVM possible kernel will cause a slowdown
  when not using PR KVM.
- A boot time option to disable SCV to use PR KVM is user-hostile.
- System call instruction emulation for SCV facility unavailable
  instructions is too complex and old emulation code was subtly broken
  and removed.

Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Reviewed-by: Fabiano Rosas 
Link: https://lore.kernel.org/r/20220222064727.2314380-2-npiggin@gmail.com

Merge branch 'akpm' (patches from Andrew)

2022-01-20T08:41:01+00:00

Merge more updates from Andrew Morton:
 "55 patches.

  Subsystems affected by this patch series: percpu, procfs, sysctl,
  misc, core-kernel, get_maintainer, lib, checkpatch, binfmt, nilfs2,
  hfs, fat, adfs, panic, delayacct, kconfig, kcov, and ubsan"

* emailed patches from Andrew Morton : (55 commits)
  lib: remove redundant assignment to variable ret
  ubsan: remove CONFIG_UBSAN_OBJECT_SIZE
  kcov: fix generic Kconfig dependencies if ARCH_WANTS_NO_INSTR
  lib/Kconfig.debug: make TEST_KMOD depend on PAGE_SIZE_LESS_THAN_256KB
  btrfs: use generic Kconfig option for 256kB page size limit
  arch/Kconfig: split PAGE_SIZE_LESS_THAN_256KB from PAGE_SIZE_LESS_THAN_64KB
  configs: introduce debug.config for CI-like setup
  delayacct: track delays from memory compact
  Documentation/accounting/delay-accounting.rst: add thrashing page cache and direct compact
  delayacct: cleanup flags in struct task_delay_info and functions use it
  delayacct: fix incomplete disable operation when switch enable to disable
  delayacct: support swapin delay accounting for swapping without blkio
  panic: remove oops_id
  panic: use error_report_end tracepoint on warnings
  fs/adfs: remove unneeded variable make code cleaner
  FAT: use io_schedule_timeout() instead of congestion_wait()
  hfsplus: use struct_group_attr() for memcpy() region
  nilfs2: remove redundant pointer sbufs
  fs/binfmt_elf: use PT_LOAD p_align values for static PIE
  const_structs.checkpatch: add frequently used ops structs
  ...

mm: percpu: add generic pcpu_populate_pte() function

2022-01-20T06:52:52+00:00

With NEED_PER_CPU_PAGE_FIRST_CHUNK enabled, we need a function to
populate pte, this patch adds a generic pcpu populate pte function,
pcpu_populate_pte(), which is marked __weak and used on most
architectures, but it is overridden on x86, which has its own
implementation.

Link: https://lkml.kernel.org/r/20211216112359.103822-5-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: "H. Peter Anvin" 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: Dennis Zhou 
Cc: Tejun Heo 
Cc: Christoph Lameter 
Cc: Albert Ou 
Cc: Catalin Marinas 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Thomas Bogendoerfer 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: percpu: add generic pcpu_fc_alloc/free funciton

2022-01-20T06:52:52+00:00

With the previous patch, we could add a generic pcpu first chunk
allocate and free function to cleanup the duplicated definations on each
architecture.

Link: https://lkml.kernel.org/r/20211216112359.103822-4-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Cc: Thomas Bogendoerfer 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: "H. Peter Anvin" 
Cc: Greg Kroah-Hartman 
Cc: Dennis Zhou 
Cc: Tejun Heo 
Cc: Christoph Lameter 
Cc: Albert Ou 
Cc: Catalin Marinas 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: "Rafael J. Wysocki" 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: percpu: add pcpu_fc_cpu_to_node_fn_t typedef

2022-01-20T06:52:52+00:00

Add pcpu_fc_cpu_to_node_fn_t and pass it into pcpu_fc_alloc_fn_t, pcpu
first chunk allocation will call it to alloc memblock on the
corresponding node by it, this is prepare for the next patch.

Link: https://lkml.kernel.org/r/20211216112359.103822-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang 
Cc: Thomas Bogendoerfer 
Cc: Michael Ellerman 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: "H. Peter Anvin" 
Cc: Greg Kroah-Hartman 
Cc: "Rafael J. Wysocki" 
Cc: Dennis Zhou 
Cc: Tejun Heo 
Cc: Christoph Lameter 
Cc: Albert Ou 
Cc: Catalin Marinas 
Cc: Palmer Dabbelt 
Cc: Paul Walmsley 
Cc: Will Deacon 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

powerpc/kernel: Add __init attribute to eligible functions

2021-12-23T11:33:10+00:00

Some functions defined in `arch/powerpc/kernel` (and one in `arch/powerpc/
kexec`) are deserving of an `__init` macro attribute. These functions are
only called by other initialization functions and therefore should inherit
the attribute.
Also, change function declarations in header files to include `__init`.

Signed-off-by: Nick Child 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211216220035.605465-2-nick.child@ibm.com

powerpc/64s: Move hash MMU support code under CONFIG_PPC_64S_HASH_MMU

2021-12-09T11:41:13+00:00

Compiling out hash support code when CONFIG_PPC_64S_HASH_MMU=n saves
128kB kernel image size (90kB text) on powernv_defconfig minus KVM,
350kB on pseries_defconfig minus KVM, 40kB on a tiny config.

Signed-off-by: Nicholas Piggin 
[mpe: Fixup defined(ARCH_HAS_MEMREMAP_COMPAT_ALIGN), which needs CONFIG.
      Fix radix_enabled() use in setup_initial_memory_limit(). Add some
      stubs to reduce number of ifdefs.]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211201144153.2456614-18-npiggin@gmail.com

powerpc/64: pcpu setup avoid reading mmu_linear_psize on 64e or radix

2021-12-02T11:57:23+00:00

Radix never sets mmu_linear_psize so it's always 4K, which causes pcpu
atom_size to always be PAGE_SIZE. 64e sets it to 1GB always.

Make paths for these platforms to be explicit about what value they set
atom_size to.

Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20211201144153.2456614-12-npiggin@gmail.com