linux-stable.git/arch/powerpc/include/asm, branch v6.14

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2025-03-01T21:44:51+00:00

Pull arm64 fixes from Will Deacon:
 "Ryan's been hard at work finding and fixing mm bugs in the arm64 code,
  so here's a small crop of fixes for -rc5.

  The main changes are to fix our zapping of non-present PTEs for
  hugetlb entries created using the contiguous bit in the page-table
  rather than a block entry at the level above. Prior to these fixes, we
  were pulling the contiguous bit back out of the PTE in order to
  determine the size of the hugetlb page but this is clearly bogus if
  the thing isn't present and consequently both the clearing of the
  PTE(s) and the TLB invalidation were unreliable.

  Although the problem was found by code inspection, we really don't
  want this sitting around waiting to trigger and the changes are CC'd
  to stable accordingly.

  Note that the diffstat looks a lot worse than it really is;
  huge_ptep_get_and_clear() now takes a size argument from the core code
  and so all the arch implementations of that have been updated in a
  pretty mechanical fashion.

   - Fix a sporadic boot failure due to incorrect randomization of the
     linear map on systems that support it

   - Fix the zapping (both clearing the entries *and* invalidating the
     TLB) of hugetlb PTEs constructed using the contiguous bit"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: hugetlb: Fix flush_hugetlb_tlb_range() invalidation level
  arm64: hugetlb: Fix huge_ptep_get_and_clear() for non-present ptes
  mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()
  arm64/mm: Fix Boot panic on Ampere Altra

mm: hugetlb: Add huge page size param to huge_ptep_get_and_clear()

2025-02-27T17:40:57+00:00

In order to fix a bug, arm64 needs to be told the size of the huge page
for which the huge_pte is being cleared in huge_ptep_get_and_clear().
Provide for this by adding an `unsigned long sz` parameter to the
function. This follows the same pattern as huge_pte_clear() and
set_huge_pte_at().

This commit makes the required interface modifications to the core mm as
well as all arches that implement this function (arm64, loongarch, mips,
parisc, powerpc, riscv, s390, sparc). The actual arm64 bug will be fixed
in a separate commit.

Cc: stable@vger.kernel.org
Fixes: 66b3923a1a0f ("arm64: hugetlb: add support for PTE contiguous bit")
Acked-by: David Hildenbrand 
Reviewed-by: Alexandre Ghiti  # riscv
Reviewed-by: Christophe Leroy 
Reviewed-by: Catalin Marinas 
Reviewed-by: Anshuman Khandual 
Signed-off-by: Ryan Roberts 
Acked-by: Alexander Gordeev  # s390
Link: https://lore.kernel.org/r/20250226120656.2400136-2-ryan.roberts@arm.com
Signed-off-by: Will Deacon

powerpc/64s: Rewrite __real_pte() and __rpte_to_hidx() as static inline

2025-02-10T04:31:22+00:00

Rewrite __real_pte() and __rpte_to_hidx() as static inline in order to
avoid following warnings/errors when building with 4k page size:

	  CC      arch/powerpc/mm/book3s64/hash_tlb.o
	arch/powerpc/mm/book3s64/hash_tlb.c: In function 'hpte_need_flush':
	arch/powerpc/mm/book3s64/hash_tlb.c:49:16: error: variable 'offset' set but not used [-Werror=unused-but-set-variable]
	   49 |         int i, offset;
	      |                ^~~~~~

	  CC      arch/powerpc/mm/book3s64/hash_native.o
	arch/powerpc/mm/book3s64/hash_native.c: In function 'native_flush_hash_range':
	arch/powerpc/mm/book3s64/hash_native.c:782:29: error: variable 'index' set but not used [-Werror=unused-but-set-variable]
	  782 |         unsigned long hash, index, hidx, shift, slot;
	      |                             ^~~~~

Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202501081741.AYFwybsq-lkp@intel.com/
Fixes: ff31e105464d ("powerpc/mm/hash64: Store the slot information at the right offset for hugetlb")
Signed-off-by: Christophe Leroy 
Reviewed-by: Ritesh Harjani (IBM) 
Signed-off-by: Madhavan Srinivasan 
Link: https://patch.msgid.link/e0d340a5b7bd478ecbf245d826e6ab2778b74e06.1736706263.git.christophe.leroy@csgroup.eu

Merge tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-01-27T02:36:23+00:00

Pull MM updates from Andrew Morton:
 "The various patchsets are summarized below. Plus of course many
  indivudual patches which are described in their changelogs.

   - "Allocate and free frozen pages" from Matthew Wilcox reorganizes
     the page allocator so we end up with the ability to allocate and
     free zero-refcount pages. So that callers (ie, slab) can avoid a
     refcount inc & dec

   - "Support large folios for tmpfs" from Baolin Wang teaches tmpfs to
     use large folios other than PMD-sized ones

   - "Fix mm/rodata_test" from Petr Tesarik performs some maintenance
     and fixes for this small built-in kernel selftest

   - "mas_anode_descend() related cleanup" from Wei Yang tidies up part
     of the mapletree code

   - "mm: fix format issues and param types" from Keren Sun implements a
     few minor code cleanups

   - "simplify split calculation" from Wei Yang provides a few fixes and
     a test for the mapletree code

   - "mm/vma: make more mmap logic userland testable" from Lorenzo
     Stoakes continues the work of moving vma-related code into the
     (relatively) new mm/vma.c

   - "mm/page_alloc: gfp flags cleanups for alloc_contig_*()" from David
     Hildenbrand cleans up and rationalizes handling of gfp flags in the
     page allocator

   - "readahead: Reintroduce fix for improper RA window sizing" from Jan
     Kara is a second attempt at fixing a readahead window sizing issue.
     It should reduce the amount of unnecessary reading

   - "synchronously scan and reclaim empty user PTE pages" from Qi Zheng
     addresses an issue where "huge" amounts of pte pagetables are
     accumulated:

       https://lore.kernel.org/lkml/cover.1718267194.git.zhengqi.arch@bytedance.com/

     Qi's series addresses this windup by synchronously freeing PTE
     memory within the context of madvise(MADV_DONTNEED)

   - "selftest/mm: Remove warnings found by adding compiler flags" from
     Muhammad Usama Anjum fixes some build warnings in the selftests
     code when optional compiler warnings are enabled

   - "mm: don't use __GFP_HARDWALL when migrating remote pages" from
     David Hildenbrand tightens the allocator's observance of
     __GFP_HARDWALL

   - "pkeys kselftests improvements" from Kevin Brodsky implements
     various fixes and cleanups in the MM selftests code, mainly
     pertaining to the pkeys tests

   - "mm/damon: add sample modules" from SeongJae Park enhances DAMON to
     estimate application working set size

   - "memcg/hugetlb: Rework memcg hugetlb charging" from Joshua Hahn
     provides some cleanups to memcg's hugetlb charging logic

   - "mm/swap_cgroup: remove global swap cgroup lock" from Kairui Song
     removes the global swap cgroup lock. A speedup of 10% for a
     tmpfs-based kernel build was demonstrated

   - "zram: split page type read/write handling" from Sergey Senozhatsky
     has several fixes and cleaups for zram in the area of
     zram_write_page(). A watchdog softlockup warning was eliminated

   - "move pagetable_*_dtor() to __tlb_remove_table()" from Kevin
     Brodsky cleans up the pagetable destructor implementations. A rare
     use-after-free race is fixed

   - "mm/debug: introduce and use VM_WARN_ON_VMG()" from Lorenzo Stoakes
     simplifies and cleans up the debugging code in the VMA merging
     logic

   - "Account page tables at all levels" from Kevin Brodsky cleans up
     and regularizes the pagetable ctor/dtor handling. This results in
     improvements in accounting accuracy

   - "mm/damon: replace most damon_callback usages in sysfs with new
     core functions" from SeongJae Park cleans up and generalizes
     DAMON's sysfs file interface logic

   - "mm/damon: enable page level properties based monitoring" from
     SeongJae Park increases the amount of information which is
     presented in response to DAMOS actions

   - "mm/damon: remove DAMON debugfs interface" from SeongJae Park
     removes DAMON's long-deprecated debugfs interfaces. Thus the
     migration to sysfs is completed

   - "mm/hugetlb: Refactor hugetlb allocation resv accounting" from
     Peter Xu cleans up and generalizes the hugetlb reservation
     accounting

   - "mm: alloc_pages_bulk: small API refactor" from Luiz Capitulino
     removes a never-used feature of the alloc_pages_bulk() interface

   - "mm/damon: extend DAMOS filters for inclusion" from SeongJae Park
     extends DAMOS filters to support not only exclusion (rejecting),
     but also inclusion (allowing) behavior

   - "Add zpdesc memory descriptor for zswap.zpool" from Alex Shi
     introduces a new memory descriptor for zswap.zpool that currently
     overlaps with struct page for now. This is part of the effort to
     reduce the size of struct page and to enable dynamic allocation of
     memory descriptors

   - "mm, swap: rework of swap allocator locks" from Kairui Song redoes
     and simplifies the swap allocator locking. A speedup of 400% was
     demonstrated for one workload. As was a 35% reduction for kernel
     build time with swap-on-zram

   - "mm: update mips to use do_mmap(), make mmap_region() internal"
     from Lorenzo Stoakes reworks MIPS's use of mmap_region() so that
     mmap_region() can be made MM-internal

   - "mm/mglru: performance optimizations" from Yu Zhao fixes a few
     MGLRU regressions and otherwise improves MGLRU performance

   - "Docs/mm/damon: add tuning guide and misc updates" from SeongJae
     Park updates DAMON documentation

   - "Cleanup for memfd_create()" from Isaac Manjarres does that thing

   - "mm: hugetlb+THP folio and migration cleanups" from David
     Hildenbrand provides various cleanups in the areas of hugetlb
     folios, THP folios and migration

   - "Uncached buffered IO" from Jens Axboe implements the new
     RWF_DONTCACHE flag which provides synchronous dropbehind for
     pagecache reading and writing. To permite userspace to address
     issues with massive buildup of useless pagecache when
     reading/writing fast devices

   - "selftests/mm: virtual_address_range: Reduce memory" from Thomas
     Weißschuh fixes and optimizes some of the MM selftests"

* tag 'mm-stable-2025-01-26-14-59' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits)
  mm/compaction: fix UBSAN shift-out-of-bounds warning
  s390/mm: add missing ctor/dtor on page table upgrade
  kasan: sw_tags: use str_on_off() helper in kasan_init_sw_tags()
  tools: add VM_WARN_ON_VMG definition
  mm/damon/core: use str_high_low() helper in damos_wmark_wait_us()
  seqlock: add missing parameter documentation for raw_seqcount_try_begin()
  mm/page-writeback: consolidate wb_thresh bumping logic into __wb_calc_thresh
  mm/page_alloc: remove the incorrect and misleading comment
  zram: remove zcomp_stream_put() from write_incompressible_page()
  mm: separate move/undo parts from migrate_pages_batch()
  mm/kfence: use str_write_read() helper in get_access_type()
  selftests/mm/mkdirty: fix memory leak in test_uffdio_copy()
  kasan: hw_tags: Use str_on_off() helper in kasan_init_hw_tags()
  selftests/mm: virtual_address_range: avoid reading from VM_IO mappings
  selftests/mm: vm_util: split up /proc/self/smaps parsing
  selftests/mm: virtual_address_range: unmap chunks after validation
  selftests/mm: virtual_address_range: mmap() without PROT_WRITE
  selftests/memfd/memfd_test: fix possible NULL pointer dereference
  mm: add FGP_DONTCACHE folio creation flag
  mm: call filemap_fdatawrite_range_kick() after IOCB_DONTCACHE issue
  ...

mm: pgtable: introduce generic __tlb_remove_table()

2025-01-26T04:22:23+00:00

Several architectures (arm, arm64, riscv and x86) define exactly the same
__tlb_remove_table(), just introduce generic __tlb_remove_table() to
eliminate these duplications.

The s390 __tlb_remove_table() is nearly the same, so also make s390
__tlb_remove_table() version generic.

Link: https://lkml.kernel.org/r/ea372633d94f4d3f9f56a7ec5994bf050bf77e39.1736317725.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng 
Reviewed-by: Kevin Brodsky 
Acked-by: Andreas Larsson 		[sparc]
Acked-by: Alexander Gordeev 	[s390]
Acked-by: Arnd Bergmann 			[asm-generic]
Cc: Alexandre Ghiti 
Cc: Alexandre Ghiti 
Cc: Aneesh Kumar K.V (Arm) 
Cc: Dave Hansen 
Cc: David Hildenbrand 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Jann Horn 
Cc: Lorenzo Stoakes 
Cc: Matthew Wilcox (Oracle) 
Cc: Mike Rapoport (Microsoft) 
Cc: Muchun Song 
Cc: Nicholas Piggin 
Cc: Palmer Dabbelt 
Cc: Peter Zijlstra (Intel) 
Cc: Ryan Roberts 
Cc: Thomas Gleixner 
Cc: Vishal Moola (Oracle) 
Cc: Will Deacon 
Cc: Yu Zhao 
Signed-off-by: Andrew Morton

Merge tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

2025-01-21T23:15:28+00:00

Pull ftrace updates from Steven Rostedt:

 - Have fprobes built on top of function graph infrastructure

   The fprobe logic is an optimized kprobe that uses ftrace to attach to
   functions when a probe is needed at the start or end of the function.
   The fprobe and kretprobe logic implements a similar method as the
   function graph tracer to trace the end of the function. That is to
   hijack the return address and jump to a trampoline to do the trace
   when the function exits. To do this, a shadow stack needs to be
   created to store the original return address. Fprobes and function
   graph do this slightly differently. Fprobes (and kretprobes) has
   slots per callsite that are reserved to save the return address. This
   is fine when just a few points are traced. But users of fprobes, such
   as BPF programs, are starting to add many more locations, and this
   method does not scale.

   The function graph tracer was created to trace all functions in the
   kernel. In order to do this, when function graph tracing is started,
   every task gets its own shadow stack to hold the return address that
   is going to be traced. The function graph tracer has been updated to
   allow multiple users to use its infrastructure. Now have fprobes be
   one of those users. This will also allow for the fprobe and kretprobe
   methods to trace the return address to become obsolete. With new
   technologies like CFI that need to know about these methods of
   hijacking the return address, going toward a solution that has only
   one method of doing this will make the kernel less complex.

 - Cleanup with guard() and free() helpers

   There were several places in the code that had a lot of "goto out" in
   the error paths to either unlock a lock or free some memory that was
   allocated. But this is error prone. Convert the code over to use the
   guard() and free() helpers that let the compiler unlock locks or free
   memory when the function exits.

 - Remove disabling of interrupts in the function graph tracer

   When function graph tracer was first introduced, it could race with
   interrupts and NMIs. To prevent that race, it would disable
   interrupts and not trace NMIs. But the code has changed to allow NMIs
   and also interrupts. This change was done a long time ago, but the
   disabling of interrupts was never removed. Remove the disabling of
   interrupts in the function graph tracer is it is not needed. This
   greatly improves its performance.

 - Allow the :mod: command to enable tracing module functions on the
   kernel command line.

   The function tracer already has a way to enable functions to be
   traced in modules by writing ":mod:" into set_ftrace_filter.
   That will enable either all the functions for the module if it is
   loaded, or if it is not, it will cache that command, and when the
   module is loaded that matches , its functions will be
   enabled. This also allows init functions to be traced. But currently
   events do not have that feature.

   Because enabling function tracing can be done very early at boot up
   (before scheduling is enabled), the commands that can be done when
   function tracing is started is limited. Having the ":mod:" command to
   trace module functions as they are loaded is very useful. Update the
   kernel command line function filtering to allow it.

* tag 'ftrace-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (26 commits)
  ftrace: Implement :mod: cache filtering on kernel command line
  tracing: Adopt __free() and guard() for trace_fprobe.c
  bpf: Use ftrace_get_symaddr() for kprobe_multi probes
  ftrace: Add ftrace_get_symaddr to convert fentry_ip to symaddr
  Documentation: probes: Update fprobe on function-graph tracer
  selftests/ftrace: Add a test case for repeating register/unregister fprobe
  selftests: ftrace: Remove obsolate maxactive syntax check
  tracing/fprobe: Remove nr_maxactive from fprobe
  fprobe: Add fprobe_header encoding feature
  fprobe: Rewrite fprobe on function-graph tracer
  s390/tracing: Enable HAVE_FTRACE_GRAPH_FUNC
  ftrace: Add CONFIG_HAVE_FTRACE_GRAPH_FUNC
  bpf: Enable kprobe_multi feature if CONFIG_FPROBE is enabled
  tracing/fprobe: Enable fprobe events with CONFIG_DYNAMIC_FTRACE_WITH_ARGS
  tracing: Add ftrace_fill_perf_regs() for perf event
  tracing: Add ftrace_partial_regs() for converting ftrace_regs to pt_regs
  fprobe: Use ftrace_regs in fprobe exit handler
  fprobe: Use ftrace_regs in fprobe entry handler
  fgraph: Pass ftrace_regs to retfunc
  fgraph: Replace fgraph_ret_regs with ftrace_regs
  ...

Merge tag 'irq-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-01-21T21:51:07+00:00

Pull interrupt subsystem updates from Thomas Gleixner:

 - Consolidate the machine_kexec_mask_interrupts() by providing a
   generic implementation and replacing the copy & pasta orgy in the
   relevant architectures.

 - Prevent unconditional operations on interrupt chips during kexec
   shutdown, which can trigger warnings in certain cases when the
   underlying interrupt has been shut down before.

 - Make the enforcement of interrupt handling in interrupt context
   unconditionally available, so that it actually works for non x86
   related interrupt chips. The earlier enablement for ARM GIC chips set
   the required chip flag, but did not notice that the check was hidden
   behind a config switch which is not selected by ARM[64].

 - Decrapify the handling of deferred interrupt affinity setting.

   Some interrupt chips require that affinity changes are made from the
   context of handling an interrupt to avoid certain race conditions.
   For x86 this was the default, but with interrupt remapping this
   requirement was lifted and a flag was introduced which tells the core
   code that affinity changes can be done in any context. Unrestricted
   affinity changes are the default for the majority of interrupt chips.

   RISCV has the requirement to add the deferred mode to one of it's
   interrupt controllers, but with the original implementation this
   would require to add the any context flag to all other RISC-V
   interrupt chips. That's backwards, so reverse the logic and require
   that chips, which need the deferred mode have to be marked
   accordingly. That avoids chasing the 'sane' chips and marking them.

 - Add multi-node support to the Loongarch AVEC interrupt controller
   driver.

 - The usual tiny cleanups, fixes and improvements all over the place.

* tag 'irq-core-2025-01-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/generic_chip: Export irq_gc_mask_disable_and_ack_set()
  genirq/timings: Add kernel-doc for a function parameter
  genirq: Remove IRQ_MOVE_PCNTXT and related code
  x86/apic: Convert to IRQCHIP_MOVE_DEFERRED
  genirq: Provide IRQCHIP_MOVE_DEFERRED
  hexagon: Remove GENERIC_PENDING_IRQ leftover
  ARC: Remove GENERIC_PENDING_IRQ
  genirq: Remove handle_enforce_irqctx() wrapper
  genirq: Make handle_enforce_irqctx() unconditionally available
  irqchip/loongarch-avec: Add multi-nodes topology support
  irqchip/ts4800: Replace seq_printf() by seq_puts()
  irqchip/ti-sci-inta : Add module build support
  irqchip/ti-sci-intr: Add module build support
  irqchip/irq-brcmstb-l2: Replace brcmstb_l2_mask_and_ack() by generic function
  irqchip: keystone: Use syscon_regmap_lookup_by_phandle_args
  genirq/kexec: Prevent redundant IRQ masking by checking state before shutdown
  kexec: Consolidate machine_kexec_mask_interrupts() implementation
  genirq: Reuse irq_thread_fn() for forced thread case
  genirq: Move irq_thread_fn() further up in the code

fprobe: Rewrite fprobe on function-graph tracer

2024-12-26T15:50:05+00:00

Rewrite fprobe implementation on function-graph tracer.
Major API changes are:
 -  'nr_maxactive' field is deprecated.
 -  This depends on CONFIG_DYNAMIC_FTRACE_WITH_ARGS or
    !CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS, and
    CONFIG_HAVE_FUNCTION_GRAPH_FREGS. So currently works only
    on x86_64.
 -  Currently the entry size is limited in 15 * sizeof(long).
 -  If there is too many fprobe exit handler set on the same
    function, it will fail to probe.

Signed-off-by: Masami Hiramatsu (Google) 
Acked-by: Heiko Carstens  # s390
Cc: Alexei Starovoitov 
Cc: Florent Revest 
Cc: Martin KaFai Lau 
Cc: bpf 
Cc: Alexei Starovoitov 
Cc: Jiri Olsa 
Cc: Alan Maguire 
Cc: Heiko Carstens 
Cc: Mark Rutland 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Huacai Chen 
Cc: WANG Xuerui 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Christophe Leroy 
Cc: Naveen N Rao 
Cc: Madhavan Srinivasan 
Cc: Paul Walmsley 
Cc: Palmer Dabbelt 
Cc: Albert Ou 
Cc: Vasily Gorbik 
Cc: Alexander Gordeev 
Cc: Christian Borntraeger 
Cc: Sven Schnelle 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: x86@kernel.org
Cc: "H. Peter Anvin" 
Cc: Mathieu Desnoyers 
Cc: Andrew Morton 
Link: https://lore.kernel.org/173519003970.391279.14406792285453830996.stgit@devnote2
Signed-off-by: Steven Rostedt (Google)

tracing: Add ftrace_fill_perf_regs() for perf event

2024-12-26T15:50:04+00:00

Add ftrace_fill_perf_regs() which should be compatible with the
perf_fetch_caller_regs(). In other words, the pt_regs returned from the
ftrace_fill_perf_regs() must satisfy 'user_mode(regs) == false' and can be
used for stack tracing.

Signed-off-by: Masami Hiramatsu (Google) 
Acked-by: Will Deacon 
Acked-by: Heiko Carstens  # s390
Cc: Alexei Starovoitov 
Cc: Florent Revest 
Cc: Martin KaFai Lau 
Cc: bpf 
Cc: Alexei Starovoitov 
Cc: Jiri Olsa 
Cc: Alan Maguire 
Cc: Heiko Carstens 
Cc: Mark Rutland 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Cc: Christophe Leroy 
Cc: Naveen N Rao 
Cc: Madhavan Srinivasan 
Cc: Vasily Gorbik 
Cc: Alexander Gordeev 
Cc: Christian Borntraeger 
Cc: Sven Schnelle 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: x86@kernel.org
Cc: "H. Peter Anvin" 
Link: https://lore.kernel.org/173518997908.391279.15910334347345106424.stgit@devnote2
Signed-off-by: Steven Rostedt (Google)

powerpc: Add preempt lazy support

2024-12-19T08:51:08+00:00

Define preempt lazy bit for Powerpc. Use bit 9 which is free and within
16 bit range of NEED_RESCHED, so compiler can issue single andi.

Since Powerpc doesn't use the generic entry/exit, add lazy check at exit
to user. CONFIG_PREEMPTION is defined for lazy/full/rt so use it for
return to kernel.

Ran a few benchmarks and db workload on Power10. Performance is close to
preempt=none/voluntary.

Since Powerpc systems can have large core count and large memory,
preempt lazy is going to be helpful in avoiding soft lockup issues.

Reviewed-by: Sebastian Andrzej Siewior 
Reviewed-by: Ankur Arora 
Signed-off-by: Shrikanth Hegde 
Signed-off-by: Madhavan Srinivasan 
Link: https://patch.msgid.link/20241116192306.88217-2-sshegde@linux.ibm.com