Commit Graph

2402 Commits

Author SHA1 Message Date
Mike Rapoport
a9ee6cf5c6 mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA
After removal of DISCINTIGMEM the NEED_MULTIPLE_NODES and NUMA
configuration options are equivalent.

Drop CONFIG_NEED_MULTIPLE_NODES and use CONFIG_NUMA instead.

Done with

	$ sed -i 's/CONFIG_NEED_MULTIPLE_NODES/CONFIG_NUMA/' \
		$(git grep -wl CONFIG_NEED_MULTIPLE_NODES)
	$ sed -i 's/NEED_MULTIPLE_NODES/NUMA/' \
		$(git grep -wl NEED_MULTIPLE_NODES)

with manual tweaks afterwards.

[rppt@linux.ibm.com: fix arm boot crash]
  Link: https://lkml.kernel.org/r/YMj9vHhHOiCVN4BF@linux.ibm.com

Link: https://lkml.kernel.org/r/20210608091316.3622-9-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Mike Rapoport
bb1c50d396 mm: remove CONFIG_DISCONTIGMEM
There are no architectures that support DISCONTIGMEM left.

Remove the configuration option and the dead code it was guarding in the
generic memory management code.

Link: https://lkml.kernel.org/r/20210608091316.3622-6-rppt@kernel.org
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:55 -07:00
Daniel Axtens
c0f8aa4fa8 mm: define default MAX_PTRS_PER_* in include/pgtable.h
Commit c65e774fb3 ("x86/mm: Make PGDIR_SHIFT and PTRS_PER_P4D variable")
made PTRS_PER_P4D variable on x86 and introduced MAX_PTRS_PER_P4D as a
constant for cases which need a compile-time constant (e.g.  fixed-size
arrays).

powerpc likewise has boot-time selectable MMU features which can cause
other mm "constants" to vary.  For KASAN, we have some static
PTE/PMD/PUD/P4D arrays so we need compile-time maximums for all these
constants.  Extend the MAX_PTRS_PER_ idiom, and place default definitions
in include/pgtable.h.  These define MAX_PTRS_PER_x to be PTRS_PER_x unless
an architecture has defined MAX_PTRS_PER_x in its arch headers.

Clean up pgtable-nop4d.h and s390's MAX_PTRS_PER_P4D definitions while
we're at it: both can just pick up the default now.

Link: https://lkml.kernel.org/r/20210624034050.511391-4-dja@axtens.net
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:53 -07:00
Tanner Love
a358f40600 once: implement DO_ONCE_LITE for non-fast-path "do once" functionality
Certain uses of "do once" functionality reside outside of fast path,
and so do not require jump label patching via static keys, making
existing DO_ONCE undesirable in such cases.

Replace uses of __section(".data.once") with DO_ONCE_LITE(_IF)?

This patch changes the return values of xfs_printk_once, printk_once,
and printk_deferred_once. Before, they returned whether the print was
performed, but now, they always return true. This is okay because the
return values of the following macros are entirely ignored throughout
the kernel:
- xfs_printk_once
- xfs_warn_once
- xfs_notice_once
- xfs_info_once
- printk_once
- pr_emerg_once
- pr_alert_once
- pr_crit_once
- pr_err_once
- pr_warn_once
- pr_notice_once
- pr_info_once
- pr_devel_once
- pr_debug_once
- printk_deferred_once
- orc_warn

Changes
v3:
  - Expand commit message to explain why changing return values of
    xfs_printk_once, printk_once, printk_deferred_once is benign
v2:
  - Fix i386 build warnings

Signed-off-by: Tanner Love <tannerlove@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Mahesh Bandewar <maheshb@google.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-28 15:54:57 -07:00
Linus Torvalds
36824f198c Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
 "This covers all architectures (except MIPS) so I don't expect any
  other feature pull requests this merge window.

  ARM:

   - Add MTE support in guests, complete with tag save/restore interface

   - Reduce the impact of CMOs by moving them in the page-table code

   - Allow device block mappings at stage-2

   - Reduce the footprint of the vmemmap in protected mode

   - Support the vGIC on dumb systems such as the Apple M1

   - Add selftest infrastructure to support multiple configuration and
     apply that to PMU/non-PMU setups

   - Add selftests for the debug architecture

   - The usual crop of PMU fixes

  PPC:

   - Support for the H_RPT_INVALIDATE hypercall

   - Conversion of Book3S entry/exit to C

   - Bug fixes

  S390:

   - new HW facilities for guests

   - make inline assembly more robust with KASAN and co

  x86:

   - Allow userspace to handle emulation errors (unknown instructions)

   - Lazy allocation of the rmap (host physical -> guest physical
     address)

   - Support for virtualizing TSC scaling on VMX machines

   - Optimizations to avoid shattering huge pages at the beginning of
     live migration

   - Support for initializing the PDPTRs without loading them from
     memory

   - Many TLB flushing cleanups

   - Refuse to load if two-stage paging is available but NX is not (this
     has been a requirement in practice for over a year)

   - A large series that separates the MMU mode (WP/SMAP/SMEP etc.) from
     CR0/CR4/EFER, using the MMU mode everywhere once it is computed
     from the CPU registers

   - Use PM notifier to notify the guest about host suspend or hibernate

   - Support for passing arguments to Hyper-V hypercalls using XMM
     registers

   - Support for Hyper-V TLB flush hypercalls and enlightened MSR bitmap
     on AMD processors

   - Hide Hyper-V hypercalls that are not included in the guest CPUID

   - Fixes for live migration of virtual machines that use the Hyper-V
     "enlightened VMCS" optimization of nested virtualization

   - Bugfixes (not many)

  Generic:

   - Support for retrieving statistics without debugfs

   - Cleanups for the KVM selftests API"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (314 commits)
  KVM: x86: rename apic_access_page_done to apic_access_memslot_enabled
  kvm: x86: disable the narrow guest module parameter on unload
  selftests: kvm: Allows userspace to handle emulation errors.
  kvm: x86: Allow userspace to handle emulation errors
  KVM: x86/mmu: Let guest use GBPAGES if supported in hardware and TDP is on
  KVM: x86/mmu: Get CR4.SMEP from MMU, not vCPU, in shadow page fault
  KVM: x86/mmu: Get CR0.WP from MMU, not vCPU, in shadow page fault
  KVM: x86/mmu: Drop redundant rsvd bits reset for nested NPT
  KVM: x86/mmu: Optimize and clean up so called "last nonleaf level" logic
  KVM: x86: Enhance comments for MMU roles and nested transition trickiness
  KVM: x86/mmu: WARN on any reserved SPTE value when making a valid SPTE
  KVM: x86/mmu: Add helpers to do full reserved SPTE checks w/ generic MMU
  KVM: x86/mmu: Use MMU's role to determine PTTYPE
  KVM: x86/mmu: Collapse 32-bit PAE and 64-bit statements for helpers
  KVM: x86/mmu: Add a helper to calculate root from role_regs
  KVM: x86/mmu: Add helper to update paging metadata
  KVM: x86/mmu: Don't update nested guest's paging bitmasks if CR0.PG=0
  KVM: x86/mmu: Consolidate reset_rsvds_bits_mask() calls
  KVM: x86/mmu: Use MMU role_regs to get LA57, and drop vCPU LA57 helper
  KVM: x86/mmu: Get nested MMU's root level from the MMU's role
  ...
2021-06-28 15:40:51 -07:00
Linus Torvalds
54a728dc5e Merge tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler udpates from Ingo Molnar:

 - Changes to core scheduling facilities:

    - Add "Core Scheduling" via CONFIG_SCHED_CORE=y, which enables
      coordinated scheduling across SMT siblings. This is a much
      requested feature for cloud computing platforms, to allow the
      flexible utilization of SMT siblings, without exposing untrusted
      domains to information leaks & side channels, plus to ensure more
      deterministic computing performance on SMT systems used by
      heterogenous workloads.

      There are new prctls to set core scheduling groups, which allows
      more flexible management of workloads that can share siblings.

    - Fix task->state access anti-patterns that may result in missed
      wakeups and rename it to ->__state in the process to catch new
      abuses.

 - Load-balancing changes:

    - Tweak newidle_balance for fair-sched, to improve 'memcache'-like
      workloads.

    - "Age" (decay) average idle time, to better track & improve
      workloads such as 'tbench'.

    - Fix & improve energy-aware (EAS) balancing logic & metrics.

    - Fix & improve the uclamp metrics.

    - Fix task migration (taskset) corner case on !CONFIG_CPUSET.

    - Fix RT and deadline utilization tracking across policy changes

    - Introduce a "burstable" CFS controller via cgroups, which allows
      bursty CPU-bound workloads to borrow a bit against their future
      quota to improve overall latencies & batching. Can be tweaked via
      /sys/fs/cgroup/cpu/<X>/cpu.cfs_burst_us.

    - Rework assymetric topology/capacity detection & handling.

 - Scheduler statistics & tooling:

    - Disable delayacct by default, but add a sysctl to enable it at
      runtime if tooling needs it. Use static keys and other
      optimizations to make it more palatable.

    - Use sched_clock() in delayacct, instead of ktime_get_ns().

 - Misc cleanups and fixes.

* tag 'sched-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
  sched/doc: Update the CPU capacity asymmetry bits
  sched/topology: Rework CPU capacity asymmetry detection
  sched/core: Introduce SD_ASYM_CPUCAPACITY_FULL sched_domain flag
  psi: Fix race between psi_trigger_create/destroy
  sched/fair: Introduce the burstable CFS controller
  sched/uclamp: Fix uclamp_tg_restrict()
  sched/rt: Fix Deadline utilization tracking during policy change
  sched/rt: Fix RT utilization tracking during policy change
  sched: Change task_struct::state
  sched,arch: Remove unused TASK_STATE offsets
  sched,timer: Use __set_current_state()
  sched: Add get_current_state()
  sched,perf,kvm: Fix preemption condition
  sched: Introduce task_is_running()
  sched: Unbreak wakeups
  sched/fair: Age the average idle time
  sched/cpufreq: Consider reduced CPU capacity in energy calculation
  sched/fair: Take thermal pressure into account while estimating energy
  thermal/cpufreq_cooling: Update offline CPUs per-cpu thermal_pressure
  sched/fair: Return early from update_tg_cfs_load() if delta == 0
  ...
2021-06-28 12:14:19 -07:00
Linus Torvalds
a15286c63d Merge tag 'locking-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:

 - Core locking & atomics:

     - Convert all architectures to ARCH_ATOMIC: move every architecture
       to ARCH_ATOMIC, then get rid of ARCH_ATOMIC and all the
       transitory facilities and #ifdefs.

       Much reduction in complexity from that series:

           63 files changed, 756 insertions(+), 4094 deletions(-)

     - Self-test enhancements

 - Futexes:

     - Add the new FUTEX_LOCK_PI2 ABI, which is a variant that doesn't
       set FLAGS_CLOCKRT (.e. uses CLOCK_MONOTONIC).

       [ The temptation to repurpose FUTEX_LOCK_PI's implicit setting of
         FLAGS_CLOCKRT & invert the flag's meaning to avoid having to
         introduce a new variant was resisted successfully. ]

     - Enhance futex self-tests

 - Lockdep:

     - Fix dependency path printouts

     - Optimize trace saving

     - Broaden & fix wait-context checks

 - Misc cleanups and fixes.

* tag 'locking-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  locking/lockdep: Correct the description error for check_redundant()
  futex: Provide FUTEX_LOCK_PI2 to support clock selection
  futex: Prepare futex_lock_pi() for runtime clock selection
  lockdep/selftest: Remove wait-type RCU_CALLBACK tests
  lockdep/selftests: Fix selftests vs PROVE_RAW_LOCK_NESTING
  lockdep: Fix wait-type for empty stack
  locking/selftests: Add a selftest for check_irq_usage()
  lockding/lockdep: Avoid to find wrong lock dep path in check_irq_usage()
  locking/lockdep: Remove the unnecessary trace saving
  locking/lockdep: Fix the dep path printing for backwards BFS
  selftests: futex: Add futex compare requeue test
  selftests: futex: Add futex wait test
  seqlock: Remove trailing semicolon in macros
  locking/lockdep: Reduce LOCKDEP dependency list
  locking/lockdep,doc: Improve readability of the block matrix
  locking/atomics: atomic-instrumented: simplify ifdeffery
  locking/atomic: delete !ARCH_ATOMIC remnants
  locking/atomic: xtensa: move to ARCH_ATOMIC
  locking/atomic: sparc: move to ARCH_ATOMIC
  locking/atomic: sh: move to ARCH_ATOMIC
  ...
2021-06-28 11:45:29 -07:00
Ingo Molnar
b2c0931a07 Merge branch 'sched/urgent' into sched/core, to resolve conflicts
This commit in sched/urgent moved the cfs_rq_is_decayed() function:

  a7b359fc6a: ("sched/fair: Correctly insert cfs_rq's to list on unthrottle")

and this fresh commit in sched/core modified it in the old location:

  9e077b52d8: ("sched/pelt: Check that *_avg are null when *_sum are")

Merge the two variants.

Conflicts:
	kernel/sched/fair.c

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-06-18 11:31:25 +02:00
Johannes Berg
ca2e334232 lib: add iomem emulation (logic_iomem)
Add IO memory emulation that uses callbacks for read/write to
the allocated regions. The callbacks can be registered by the
users using logic_iomem_alloc().

To use, an architecture must 'select LOGIC_IOMEM' in Kconfig
and then include <asm-generic/logic_io.h> into asm/io.h to get
the __raw_read*/__raw_write* functions.

Optionally, an architecture may 'select LOGIC_IOMEM_FALLBACK'
in which case non-emulated regions will 'fall back' to the
various real_* functions that must then be provided.

Cc: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
2021-06-17 21:44:51 +02:00
Vitaly Kuznetsov
f15cdceab5 asm-generic/hyperv: add HV_STATUS_ACCESS_DENIED definition
From TLFSv6.0b, this status means: "The caller did not possess sufficient
access rights to perform the requested operation."

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210521095204.2161214-2-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-17 13:09:38 -04:00
Nathan Chancellor
d4c6399900 vmlinux.lds.h: Avoid orphan section with !SMP
With x86_64_defconfig and the following configs, there is an orphan
section warning:

CONFIG_SMP=n
CONFIG_AMD_MEM_ENCRYPT=y
CONFIG_HYPERVISOR_GUEST=y
CONFIG_KVM=y
CONFIG_PARAVIRT=y

ld: warning: orphan section `.data..decrypted' from `arch/x86/kernel/cpu/vmware.o' being placed in section `.data..decrypted'
ld: warning: orphan section `.data..decrypted' from `arch/x86/kernel/kvm.o' being placed in section `.data..decrypted'

These sections are created with DEFINE_PER_CPU_DECRYPTED, which
ultimately turns into __PCPU_ATTRS, which in turn has a section
attribute with a value of PER_CPU_BASE_SECTION + the section name. When
CONFIG_SMP is not set, the base section is .data and that is not
currently handled in any linker script.

Add .data..decrypted to PERCPU_DECRYPTED_SECTION, which is included in
PERCPU_INPUT -> PERCPU_SECTION, which is include in the x86 linker
script when either CONFIG_X86_64 or CONFIG_SMP is unset, taking care of
the warning.

Fixes: ac26963a11 ("percpu: Introduce DEFINE_PER_CPU_DECRYPTED")
Link: https://github.com/ClangBuiltLinux/linux/issues/1360
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com> # build
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210506001410.1026691-1-nathan@kernel.org
2021-06-02 12:43:55 -07:00
Mark Rutland
bccf1ec369 locking/atomics: atomic-instrumented: simplify ifdeffery
Now that all architectures implement ARCH_ATOMIC, the fallbacks are
generated before the instrumented wrappers are generated. Due to this,
in atomic-instrumented.h we can assume that the whole set of atomic
functions has been generated. Likewise, atomic-instrumented.h doesn't
need to provide a preprocessor definition for every atomic it wraps.

This patch removes the redundant ifdeffery.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-34-mark.rutland@arm.com
2021-05-26 13:20:52 +02:00
Mark Rutland
3c1885187b locking/atomic: delete !ARCH_ATOMIC remnants
Now that all architectures implement ARCH_ATOMIC, we can make it
mandatory, removing the Kconfig symbol and logic for !ARCH_ATOMIC.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-33-mark.rutland@arm.com
2021-05-26 13:20:52 +02:00
Mark Rutland
82b993e824 locking/atomic: cmpxchg: support ARCH_ATOMIC
We'd like all architectures to convert to ARCH_ATOMIC, as this will
enable functionality, and once all architectures are converted it will
be possible to make significant cleanups to the atomic headers.

A number of architectures use asm-generic/cmpxchg.h or
asm-generic/cmpxhg-local.h, and it's impractical to convert the headers
and all these architectures in one go. To make it possible to convert
them one-by-one, let's make the asm-generic implementation function as
either cmpxchg*() or arch_cmpxchg*() depending on whether ARCH_ATOMIC is
selected. To do this, the generic implementations are prefixed as
generic_cmpxchg_*(), and preprocessor definitions map
cmpxchg_*()/arch_cmpxchg_*() onto these as appropriate.

Once all users are moved over to ARCH_ATOMIC the ifdeffery in the header
can be simplified and/or removed entirely.

For existing users (none of which select ARCH_ATOMIC), there should be
no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-13-mark.rutland@arm.com
2021-05-26 13:20:50 +02:00
Mark Rutland
6988631bdf locking/atomic: cmpxchg: make generic a prefix
The asm-generic implementations of cmpxchg_local() and cmpxchg64_local()
use a `_generic` suffix to distinguish themselves from arch code or
wrappers used elsewhere.

Subsequent patches will add ARCH_ATOMIC support to these
implementations, and will distinguish more functions with a `generic`
portion. To align with how ARCH_ATOMIC uses an `arch_` prefix, it would
be helpful to use a `generic_` prefix rather than a `_generic` suffix.

In preparation for this, this patch renames the existing functions to
make `generic` a prefix rather than a suffix. There should be no
functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-12-mark.rutland@arm.com
2021-05-26 13:20:50 +02:00
Mark Rutland
1bdadf46ef locking/atomic: atomic64: support ARCH_ATOMIC
We'd like all architectures to convert to ARCH_ATOMIC, as this will
enable functionality, and once all architectures are converted it will
be possible to make significant cleanups to the atomic headers.

A number of architectures use asm-generic/atomic64.h, and it's
impractical to convert the header and all these architectures in one go.
To make it possible to convert them one-by-one, let's make the
asm-generic implementation function as either atomic64_*() or
arch_atomic64_*() depending on whether ARCH_ATOMIC is selected. To do
this, the generic implementations are prefixed as generic_atomic64_*(),
and preprocessor definitions map atomic64_*()/arch_atomic64_*() onto
these as appropriate.

Once all users are moved over to ARCH_ATOMIC the ifdeffery in the header
can be simplified and/or removed entirely.

For existing users (none of which select ARCH_ATOMIC), there should be
no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-11-mark.rutland@arm.com
2021-05-26 13:20:50 +02:00
Mark Rutland
f8b6455a9d locking/atomic: atomic: support ARCH_ATOMIC
We'd like all architectures to convert to ARCH_ATOMIC, as this will
enable functionality, and once all architectures are converted it will
be possible to make significant cleanups to the atomic headers.

A number of architectures use asm-generic/atomic.h, and it's impractical
to convert the header and all these architectures in one go. To make it
possible to convert them one-by-one, let's make the asm-generic
implementation function as either atomic_*() or arch_atomic_*()
depending on whether ARCH_ATOMIC is selected. To do this, the C
implementations are prefixed as generic_atomic_*(), and preprocessor
definitions map atomic_*()/arch_atomic_*() onto these as
appropriate.

Once all users are moved over to ARCH_ATOMIC the ifdeffery in the header
can be simplified and/or removed entirely.

For existing users (none of which select ARCH_ATOMIC), there should be
no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-10-mark.rutland@arm.com
2021-05-26 13:20:50 +02:00
Mark Rutland
d0e03218ca locking/atomic: atomic: simplify ifdeffery
Now that asm-generic/atomic.h is only used by architectures without any
architecture-specific atomic definitions, we know that there will be no
architecture-specific implementations to override, and can remove the
ifdeffery this has previously required, bringing it into line with
asm-generic/atomic64.h.

At the same time, we can implement atomic_add() and atomic_sub()
directly using ATOMIC_OP(), since we know architectures won't provide
atomic_add_return() or atomic_sub_return().

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-9-mark.rutland@arm.com
2021-05-26 13:20:50 +02:00
Mark Rutland
89eb78d542 locking/atomic: atomic: remove redundant include
Since commit:

  560cb12a40 ("locking,arch: Rewrite generic atomic support")

... we conditionally include <linux/irqflags.h> before defining atomics
using locking, and hence do not need to do so unconditionally later in
the header.

This patch removes the redundant include.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-8-mark.rutland@arm.com
2021-05-26 13:20:50 +02:00
Mark Rutland
2609a195fb locking/atomic: atomic: remove stale comments
The commentary in asm-generic/atomic.h is stale; let's bring it up-to
date:

* The block comment at the start of the file mentions this is only
  usable on UP systems, but is immediately followed by an SMP
  implementation using cmpxchg. Let's delete the misleading statement.

* A comment near the end of the file was originally at the top of the
  file, but over time rework has shuffled it near the end, and it's long
  been superceded by the block comment at the top of the file. Let's
  remove it.

* Since asm-generic/atomic.h isn't the canonical documentation for the
  atomic ops, and since the existing comments are not in kerneldoc
  format, we don't need to document the semantics of each operation here
  (and this would be better done in a centralised document). Let's
  remove these comments.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210525140232.53872-7-mark.rutland@arm.com
2021-05-26 13:20:49 +02:00
Arnd Bergmann
803f4e1eab asm-generic: simplify asm/unaligned.h
The get_unaligned()/put_unaligned() implementations are much more complex
than necessary, now that all architectures use the same code.

Move everything into one file and use a much more compact way to express
the same logic.

I've compared the binary output using gcc-11 across defconfig builds for
all architectures and found this patch to make no difference, except for
a single function on powerpc that needs two additional register moves
because of random differences in register allocation.

There are a handful of callers of the low-level __get_unaligned_cpu32,
so leave that in place for the time being even though the common code
no longer uses it.

This adds a warning for any caller of get_unaligned()/put_unaligned()
that passes in a single-byte pointer, but I've sent patches for all
instances that show up in x86 and randconfig builds. It would be nice
to change the arguments of the endian-specific accessors to take the
matching __be16/__be32/__be64/__le16/__le32/__le64 arguments instead of
a void pointer, but that requires more changes to the rest of the kernel.

This new version does allow aggregate types into get_unaligned(), which
was not the original goal but might come in handy.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-05-17 13:30:29 +02:00
Arnd Bergmann
d40d817948 asm-generic: uaccess: 1-byte access is always aligned
With the cleaned up version of asm-generic/unaligned.h,
there is a warning about the get_user/put_user helpers using
unaligned access for single-byte variables:

include/asm-generic/uaccess.h: In function ‘__get_user_fn’:
include/asm-generic/unaligned.h:13:15: warning: ‘packed’ attribute ignored for field of type ‘u8’ {aka ‘unsigned char’} [-Wattributes]
  const struct { type x __packed; } *__pptr = (typeof(__pptr))(ptr); \

Change these to use a direct pointer dereference to avoid the
warnings.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-05-17 13:30:29 +02:00
Valentin Schneider
f1a0a376ca sched/core: Initialize the idle task with preemption disabled
As pointed out by commit

  de9b8f5dcb ("sched: Fix crash trying to dequeue/enqueue the idle thread")

init_idle() can and will be invoked more than once on the same idle
task. At boot time, it is invoked for the boot CPU thread by
sched_init(). Then smp_init() creates the threads for all the secondary
CPUs and invokes init_idle() on them.

As the hotplug machinery brings the secondaries to life, it will issue
calls to idle_thread_get(), which itself invokes init_idle() yet again.
In this case it's invoked twice more per secondary: at _cpu_up(), and at
bringup_cpu().

Given smp_init() already initializes the idle tasks for all *possible*
CPUs, no further initialization should be required. Now, removing
init_idle() from idle_thread_get() exposes some interesting expectations
with regards to the idle task's preempt_count: the secondary startup always
issues a preempt_disable(), requiring some reset of the preempt count to 0
between hot-unplug and hotplug, which is currently served by
idle_thread_get() -> idle_init().

Given the idle task is supposed to have preemption disabled once and never
see it re-enabled, it seems that what we actually want is to initialize its
preempt_count to PREEMPT_DISABLED and leave it there. Do that, and remove
init_idle() from idle_thread_get().

Secondary startups were patched via coccinelle:

  @begone@
  @@

  -preempt_disable();
  ...
  cpu_startup_entry(CPUHP_AP_ONLINE_IDLE);

Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210512094636.2958515-1-valentin.schneider@arm.com
2021-05-12 13:01:45 +02:00
Arnd Bergmann
778aaefb8e asm-generic: unaligned always use struct helpers
As found by Vineet Gupta and Linus Torvalds, gcc has somewhat unexpected
behavior when faced with overlapping unaligned pointers. The kernel's
unaligned/access-ok.h header technically invokes undefined behavior
that happens to usually work on the architectures using it, but if the
compiler optimizes code based on the assumption that undefined behavior
doesn't happen, it can create output that actually causes data corruption.

A related problem was previously found on 32-bit ARMv7, where most
instructions can be used on unaligned data, but 64-bit ldrd/strd causes
an exception. The workaround was to always use the unaligned/le_struct.h
helper instead of unaligned/access-ok.h, in commit 1cce91dfc8 ("ARM:
8715/1: add a private asm/unaligned.h").

The same solution should work on all other architectures as well, so
remove the access-ok.h variant and use the other one unconditionally on
all architectures, picking either the big-endian or little-endian version.

With this, the arm specific header can be removed as well, and the
only file including linux/unaligned/access_ok.h gets moved to including
the normal file.

Fortunately, this made almost no difference to the object code produced
by gcc-11. On x86, s390, powerpc, and arc, the resulting binary appears
to be identical to the previous version, while on arm64 and m68k there
are minimal differences that looks like an optimization pass went into
a different direction, usually using fewer stack spills on the new
version.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100363
2021-05-10 17:50:47 +02:00
Arnd Bergmann
0652035a57 asm-generic: unaligned: remove byteshift helpers
In theory, compilers should be able to work this out themselves so we
can use a simpler version based on the swab() helpers.

I have verified that this works on all supported compiler versions
(gcc-4.9 and up, clang-10 and up). Looking at the object code produced by
gcc-11, I found that the impact is mostly a change in inlining decisions
that lead to slightly larger code.

In other cases, this version produces explicit byte swaps in place of
separate byte access, or comparing against pre-swapped constants.

While the source code is clearly simpler, I have not seen an indication
of the new version actually producing better code on Arm, so maybe
we want to skip this after all. From what I can tell, gcc recognizes
the byteswap pattern in the byteshift.h header and can turn it into
explicit instructions, but it does not turn a __builtin_bswap32() back
into individual bytes when that would result in better output, e.g.
when storing a byte-reversed constant.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-05-10 17:50:47 +02:00
David Hildenbrand
f2e762bab9 mm: remove xlate_dev_kmem_ptr()
Since /dev/kmem has been removed, let's remove the xlate_dev_kmem_ptr()
leftovers.

Link: https://lkml.kernel.org/r/20210324102351.6932-3-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Rich Felker <dalias@libc.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmerdabbelt@google.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Niklas Schnelle <schnelle@linux.ibm.com>
Cc: Pierre Morel <pmorel@linux.ibm.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-07 00:26:34 -07:00
Yury Norov
2cc7b6a44a lib: add fast path for find_first_*_bit() and find_last_bit()
Similarly to bitmap functions, users would benefit if we'll handle a case
of small-size bitmaps that fit into a single word.

While here, move the find_last_bit() declaration to bitops/find.h where
other find_*_bit() functions sit.

Link: https://lkml.kernel.org/r/20210401003153.97325-11-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Alexey Klimov <aklimov@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jianpeng Ma <jianpeng.ma@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:12 -07:00
Yury Norov
277a20a498 lib: add fast path for find_next_*_bit()
Similarly to bitmap functions, find_next_*_bit() users will benefit if
we'll handle a case of bitmaps that fit into a single word inline.  In the
very best case, the compiler may replace a function call with a few
instructions.

This is the quite typical find_next_bit() user:

	unsigned int cpumask_next(int n, const struct cpumask *srcp)
	{
		/* -1 is a legal arg here. */
		if (n != -1)
			cpumask_check(n);
		return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1);
	}
	EXPORT_SYMBOL(cpumask_next);

Currently, on ARM64 the generated code looks like this:
	0000000000000000 <cpumask_next>:
	   0:   a9bf7bfd        stp     x29, x30, [sp, #-16]!
	   4:   11000402        add     w2, w0, #0x1
	   8:   aa0103e0        mov     x0, x1
	   c:   d2800401        mov     x1, #0x40                       // #64
	  10:   910003fd        mov     x29, sp
	  14:   93407c42        sxtw    x2, w2
	  18:   94000000        bl      0 <find_next_bit>
	  1c:   a8c17bfd        ldp     x29, x30, [sp], #16
	  20:   d65f03c0        ret
	  24:   d503201f        nop

After applying this patch:
	0000000000000140 <cpumask_next>:
	 140:   11000400        add     w0, w0, #0x1
	 144:   93407c00        sxtw    x0, w0
	 148:   f100fc1f        cmp     x0, #0x3f
	 14c:   54000168        b.hi    178 <cpumask_next+0x38>  // b.pmore
	 150:   f9400023        ldr     x3, [x1]
	 154:   92800001        mov     x1, #0xffffffffffffffff         // #-1
	 158:   9ac02020        lsl     x0, x1, x0
	 15c:   52800802        mov     w2, #0x40                       // #64
	 160:   8a030001        and     x1, x0, x3
	 164:   dac00020        rbit    x0, x1
	 168:   f100003f        cmp     x1, #0x0
	 16c:   dac01000        clz     x0, x0
	 170:   1a800040        csel    w0, w2, w0, eq  // eq = none
	 174:   d65f03c0        ret
	 178:   52800800        mov     w0, #0x40                       // #64
	 17c:   d65f03c0        ret

find_next_bit() call is replaced with 6 instructions.  find_next_bit()
itself is 41 instructions plus function call overhead.

Despite inlining, the scripts/bloat-o-meter report smaller .text size
after applying the series:
	add/remove: 11/9 grow/shrink: 233/176 up/down: 5780/-6768 (-988)

Link: https://lkml.kernel.org/r/20210401003153.97325-10-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Alexey Klimov <aklimov@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jianpeng Ma <jianpeng.ma@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:12 -07:00
Yury Norov
5c88af59f9 lib: inline _find_next_bit() wrappers
lib/find_bit.c declares five single-line wrappers for _find_next_bit().
We may turn those wrappers to inline functions.  It eliminates unneeded
function calls and opens room for compile-time optimizations.

Link: https://lkml.kernel.org/r/20210401003153.97325-8-yury.norov@gmail.com
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Alexey Klimov <aklimov@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jianpeng Ma <jianpeng.ma@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:12 -07:00
Yury Norov
586eaebea5 lib: extend the scope of small_const_nbits() macro
find_bit would also benefit from small_const_nbits() optimizations.  The
detailed comment is provided by Rasmus Villemoes.

Link: https://lkml.kernel.org/r/20210401003153.97325-6-yury.norov@gmail.com
Suggested-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Alexey Klimov <aklimov@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: David Sterba <dsterba@suse.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jianpeng Ma <jianpeng.ma@intel.com>
Cc: Joe Perches <joe@perches.com>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Rich Felker <dalias@libc.org>
Cc: Stefano Brivio <sbrivio@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: Wolfram Sang <wsa+renesas@sang-engineering.com>
Cc: Yoshinori Sato <ysato@users.osdn.me>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-05-06 19:24:11 -07:00
Linus Torvalds
77d51337d6 Merge tag 'mips_5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux
Pull MIPS updates from Thomas Bogendoerfer:

 - removed get_fs/set_fs

 - removed broken/unmaintained MIPS KVM trap and emulate support

 - added support for Loongson-2K1000

 - fixes and cleanups

* tag 'mips_5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux: (107 commits)
  MIPS: BCM63XX: Use BUG_ON instead of condition followed by BUG.
  MIPS: select ARCH_KEEP_MEMBLOCK unconditionally
  mips: Do not include hi and lo in clobber list for R6
  MIPS:DTS:Correct the license for Loongson-2K
  MIPS:DTS:Fix label name and interrupt number of ohci for Loongson-2K
  MIPS: Avoid handcoded DIVU in `__div64_32' altogether
  lib/math/test_div64: Correct the spelling of "dividend"
  lib/math/test_div64: Fix error message formatting
  mips/bootinfo:correct some comments of fw_arg
  MIPS: Avoid DIVU in `__div64_32' is result would be zero
  MIPS: Reinstate platform `__div64_32' handler
  div64: Correct inline documentation for `do_div'
  lib/math: Add a `do_div' test module
  MIPS: Makefile: Replace -pg with CC_FLAGS_FTRACE
  MIPS: pci-legacy: revert "use generic pci_enable_resources"
  MIPS: Loongson64: Add kexec/kdump support
  MIPS: pci-legacy: use generic pci_enable_resources
  MIPS: pci-legacy: remove busn_resource field
  MIPS: pci-legacy: remove redundant info messages
  MIPS: pci-legacy: stop using of_pci_range_to_resource
  ...
2021-04-29 11:28:08 -07:00
Linus Torvalds
57fa2369ab Merge tag 'cfi-v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull CFI on arm64 support from Kees Cook:
 "This builds on last cycle's LTO work, and allows the arm64 kernels to
  be built with Clang's Control Flow Integrity feature. This feature has
  happily lived in Android kernels for almost 3 years[1], so I'm excited
  to have it ready for upstream.

  The wide diffstat is mainly due to the treewide fixing of mismatched
  list_sort prototypes. Other things in core kernel are to address
  various CFI corner cases. The largest code portion is the CFI runtime
  implementation itself (which will be shared by all architectures
  implementing support for CFI). The arm64 pieces are Acked by arm64
  maintainers rather than coming through the arm64 tree since carrying
  this tree over there was going to be awkward.

  CFI support for x86 is still under development, but is pretty close.
  There are a handful of corner cases on x86 that need some improvements
  to Clang and objtool, but otherwise works well.

  Summary:

   - Clean up list_sort prototypes (Sami Tolvanen)

   - Introduce CONFIG_CFI_CLANG for arm64 (Sami Tolvanen)"

* tag 'cfi-v5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  arm64: allow CONFIG_CFI_CLANG to be selected
  KVM: arm64: Disable CFI for nVHE
  arm64: ftrace: use function_nocfi for ftrace_call
  arm64: add __nocfi to __apply_alternatives
  arm64: add __nocfi to functions that jump to a physical address
  arm64: use function_nocfi with __pa_symbol
  arm64: implement function_nocfi
  psci: use function_nocfi for cpu_resume
  lkdtm: use function_nocfi
  treewide: Change list_sort to use const pointers
  bpf: disable CFI in dispatcher functions
  kallsyms: strip ThinLTO hashes from static functions
  kthread: use WARN_ON_FUNCTION_MISMATCH
  workqueue: use WARN_ON_FUNCTION_MISMATCH
  module: ensure __cfi_check alignment
  mm: add generic function_nocfi macro
  cfi: add __cficanonical
  add support for Clang CFI
2021-04-27 10:16:46 -07:00
Linus Torvalds
0c85556318 Merge tag 'arm-apple-m1-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Pull ARM Apple M1 platform support from Arnd Bergmann:
 "The Apple M1 is the processor used it all current generation Apple
  Macintosh computers. Support for this platform so far is rudimentary,
  but it boots and can use framebuffer and serial console over a special
  USB cable.

  Support for several essential on-chip devices (USB, PCIe, IOMMU, NVMe)
  is work in progress but was not ready in time.

  A very detailed description of what works is in the commit message of
  commit 1bb2fd3880 ("Merge tag 'm1-soc-bringup-v5' [..]") and on the
  AsahiLinux wiki"

Link: https://lore.kernel.org/linux-arm-kernel/bdb18e9f-fcd7-1e31-2224-19c0e5090706@marcan.st/

* tag 'arm-apple-m1-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc:
  asm-generic/io.h: Unbork ioremap_np() declaration
  arm64: apple: Add initial Apple Mac mini (M1, 2020) devicetree
  dt-bindings: display: Add apple,simple-framebuffer
  arm64: Kconfig: Introduce CONFIG_ARCH_APPLE
  irqchip/apple-aic: Add support for the Apple Interrupt Controller
  dt-bindings: interrupt-controller: Add DT bindings for apple-aic
  arm64: Move ICH_ sysreg bits from arm-gic-v3.h to sysreg.h
  of/address: Add infrastructure to declare MMIO as non-posted
  asm-generic/io.h: implement pci_remap_cfgspace using ioremap_np
  arm64: Implement ioremap_np() to map MMIO as nGnRnE
  docs: driver-api: device-io: Document ioremap() variants & access funcs
  docs: driver-api: device-io: Document I/O access functions
  asm-generic/io.h:  Add a non-posted variant of ioremap()
  arm64: arch_timer: Implement support for interrupt-names
  dt-bindings: timer: arm,arch_timer: Add interrupt-names support
  arm64: cputype: Add CPU implementor & types for the Apple M1 cores
  dt-bindings: arm: cpus: Add apple,firestorm & icestorm compatibles
  dt-bindings: arm: apple: Add bindings for Apple ARM platforms
  dt-bindings: vendor-prefixes: Add apple prefix
2021-04-26 12:30:36 -07:00
Maciej W. Rozycki
f287583238 div64: Correct inline documentation for `do_div'
Correct inline documentation for `do_div', which is a function-like
macro the `n' parameter of which has the semantics of a C++ reference:
it is both read and written in the context of the caller without an
explicit dereference such as with a pointer.

In the C programming language it has no equivalent for proper functions,
in terms of which the documentation expresses the semantics of `do_div',
but substituting a pointer in documentation is misleading, and using the
C++ notation should at least raise the reader's attention and encourage
to seek explanation even if the C++ semantics is not readily understood.

While at it observe that "semantics" is an uncountable noun, so refer to
it with a singular rather than plural verb.

Signed-off-by: Maciej W. Rozycki <macro@orcam.me.uk>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
2021-04-21 13:45:36 +02:00
Joseph Salisbury
753ed9c95c drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status
There is not a consistent pattern for checking Hyper-V hypercall status.
Existing code uses a number of variants.  The variants work, but a consistent
pattern would improve the readability of the code, and be more conformant
to what the Hyper-V TLFS says about hypercall status.

Implemented new helper functions hv_result(), hv_result_success(), and
hv_repcomp().  Changed the places where hv_do_hypercall() and related variants
are used to use the helper functions.

Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-21 09:49:19 +00:00
Joseph Salisbury
6523592cee x86/hyperv: Move hv_do_rep_hypercall to asm-generic
This patch makes no functional changes.  It simply moves hv_do_rep_hypercall()
out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h

hv_do_rep_hypercall() is architecture independent, so it makes sense that it
should be in the architecture independent mshyperv.h, not in the x86-specific
mshyperv.h.

This is done in preperation for a follow up patch which creates a consistent
pattern for checking Hyper-V hypercall status.

Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1618620183-9967-1-git-send-email-joseph.salisbury@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-21 09:49:19 +00:00
Hector Martin
ea96292838 asm-generic/io.h: Unbork ioremap_np() declaration
It accidentally slipped into the #ifdef for ioremap_uc().

Signed-off-by: Hector Martin <marcan@marcan.st>
Link: https://lore.kernel.org/r/20210409052038.58925-1-marcan@marcan.st'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-04-09 08:48:27 +02:00
Sami Tolvanen
cf68fffb66 add support for Clang CFI
This change adds support for Clang’s forward-edge Control Flow
Integrity (CFI) checking. With CONFIG_CFI_CLANG, the compiler
injects a runtime check before each indirect function call to ensure
the target is a valid function with the correct static type. This
restricts possible call targets and makes it more difficult for
an attacker to exploit bugs that allow the modification of stored
function pointers. For more details, see:

  https://clang.llvm.org/docs/ControlFlowIntegrity.html

Clang requires CONFIG_LTO_CLANG to be enabled with CFI to gain
visibility to possible call targets. Kernel modules are supported
with Clang’s cross-DSO CFI mode, which allows checking between
independently compiled components.

With CFI enabled, the compiler injects a __cfi_check() function into
the kernel and each module for validating local call targets. For
cross-module calls that cannot be validated locally, the compiler
calls the global __cfi_slowpath_diag() function, which determines
the target module and calls the correct __cfi_check() function. This
patch includes a slowpath implementation that uses __module_address()
to resolve call targets, and with CONFIG_CFI_CLANG_SHADOW enabled, a
shadow map that speeds up module look-ups by ~3x.

Clang implements indirect call checking using jump tables and
offers two methods of generating them. With canonical jump tables,
the compiler renames each address-taken function to <function>.cfi
and points the original symbol to a jump table entry, which passes
__cfi_check() validation. This isn’t compatible with stand-alone
assembly code, which the compiler doesn’t instrument, and would
result in indirect calls to assembly code to fail. Therefore, we
default to using non-canonical jump tables instead, where the compiler
generates a local jump table entry <function>.cfi_jt for each
address-taken function, and replaces all references to the function
with the address of the jump table entry.

Note that because non-canonical jump table addresses are local
to each component, they break cross-module function address
equality. Specifically, the address of a global function will be
different in each module, as it's replaced with the address of a local
jump table entry. If this address is passed to a different module,
it won’t match the address of the same function taken there. This
may break code that relies on comparing addresses passed from other
components.

CFI checking can be disabled in a function with the __nocfi attribute.
Additionally, CFI can be disabled for an entire compilation unit by
filtering out CC_FLAGS_CFI.

By default, CFI failures result in a kernel panic to stop a potential
exploit. CONFIG_CFI_PERMISSIVE enables a permissive mode, where the
kernel prints out a rate-limited warning instead, and allows execution
to continue. This option is helpful for locating type mismatches, but
should only be enabled during development.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210408182843.1754385-2-samitolvanen@google.com
2021-04-08 16:04:20 -07:00
Hector Martin
7c566bb5e4 asm-generic/io.h: Add a non-posted variant of ioremap()
ARM64 currently defaults to posted MMIO (nGnRE), but some devices
require the use of non-posted MMIO (nGnRnE). Introduce a new ioremap()
variant to handle this case. ioremap_np() returns NULL on arches that
do not implement this variant.

sparc64 is the only architecture that needs to be touched directly,
because it includes neither of the generic io.h or iomap.h headers.

This adds the IORESOURCE_MEM_NONPOSTED flag, which maps to this
variant and marks a given resource as requiring non-posted mappings.
This is implemented in the resource system because it is a SoC-level
requirement, so existing drivers do not need special-case code to pick
this ioremap variant.

Then this is implemented in devres by introducing devm_ioremap_np(),
and making devm_ioremap_resource() automatically select this variant
when the resource has the IORESOURCE_MEM_NONPOSTED flag set.

Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Hector Martin <marcan@marcan.st>
2021-04-08 20:18:38 +09:00
Sunil Muthuswamy
6dc2a774cb x86/Hyper-V: Support for free page reporting
Linux has support for free page reporting now (36e66c554b) for
virtualized environment. On Hyper-V when virtually backed VMs are
configured, Hyper-V will advertise cold memory discard capability,
when supported. This patch adds the support to hook into the free
page reporting infrastructure and leverage the Hyper-V cold memory
discard hint hypercall to report/free these pages back to the host.

Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com>
Tested-by: Matheus Castello <matheus@castello.eng.br>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/SN4PR2101MB0880121FA4E2FEC67F35C1DCC0649@SN4PR2101MB0880.namprd21.prod.outlook.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-24 11:35:24 +00:00
Michael Kelley
a620bbaa35 asm-generic/hyperv: Add missing function prototypes per -W1 warnings
Add two function prototypes for -W1 warnings generated by the
kernel test robot.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1615402069-39462-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-11 10:12:22 +00:00
Michael Kelley
ec866be6ec clocksource/drivers/hyper-v: Move handling of STIMER0 interrupts
STIMER0 interrupts are most naturally modeled as per-cpu IRQs. But
because x86/x64 doesn't have per-cpu IRQs, the core STIMER0 interrupt
handling machinery is done in code under arch/x86 and Linux IRQs are
not used. Adding support for ARM64 means adding equivalent code
using per-cpu IRQs under arch/arm64.

A better model is to treat per-cpu IRQs as the normal path (which it is
for modern architectures), and the x86/x64 path as the exception. Do this
by incorporating standard Linux per-cpu IRQ allocation into the main
SITMER0 driver code, and bypass it in the x86/x64 exception case. For
x86/x64, special case code is retained under arch/x86, but no STIMER0
interrupt handling code is needed under arch/arm64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1614721102-2241-11-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:33:00 +00:00
Michael Kelley
d608715d47 Drivers: hv: vmbus: Move handling of VMbus interrupts
VMbus interrupts are most naturally modelled as per-cpu IRQs.  But
because x86/x64 doesn't have per-cpu IRQs, the core VMbus interrupt
handling machinery is done in code under arch/x86 and Linux IRQs are
not used.  Adding support for ARM64 means adding equivalent code
using per-cpu IRQs under arch/arm64.

A better model is to treat per-cpu IRQs as the normal path (which it is
for modern architectures), and the x86/x64 path as the exception.  Do this
by incorporating standard Linux per-cpu IRQ allocation into the main VMbus
driver, and bypassing it in the x86/x64 exception case. For x86/x64,
special case code is retained under arch/x86, but no VMbus interrupt
handling code is needed under arch/arm64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-7-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:33:00 +00:00
Michael Kelley
b548a77427 Drivers: hv: vmbus: Move hyperv_report_panic_msg to arch neutral code
With the new Hyper-V MSR set function, hyperv_report_panic_msg() can be
architecture neutral, so move it out from under arch/x86 and merge into
hv_kmsg_dump(). This move also avoids needing a separate implementation
under arch/arm64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-5-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:32:59 +00:00
Michael Kelley
f3c5e63c36 Drivers: hv: Redo Hyper-V synthetic MSR get/set functions
Current code defines a separate get and set macro for each Hyper-V
synthetic MSR used by the VMbus driver. Furthermore, the get macro
can't be converted to a standard function because the second argument
is modified in place, which is somewhat bad form.

Redo this by providing a single get and a single set function that
take a parameter specifying the MSR to be operated on. Fixup usage
of the get function. Calling locations are no more complex than before,
but the code under arch/x86 and the upcoming code under arch/arm64
is significantly simplified.

Also standardize the names of Hyper-V synthetic MSRs that are
architecture neutral. But keep the old x86-specific names as aliases
that can be removed later when all references (particularly in KVM
code) have been cleaned up in a separate patch series.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-4-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:32:59 +00:00
Michael Kelley
5e4e6ddf8d x86/hyper-v: Move hv_message_type to architecture neutral module
The definition of enum hv_message_type includes arch neutral and
x86/x64-specific values. Ideally there would be a way to put the
arch neutral values in an arch neutral module, and the arch
specific values in an arch specific module. But C doesn't provide
a way to extend enum types. As a compromise, move the entire
definition into an arch neutral module, to avoid duplicating the
arch neutral values for x86/x64 and for ARM64.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-3-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:32:59 +00:00
Michael Kelley
ca48739e59 Drivers: hv: vmbus: Move Hyper-V page allocator to arch neutral code
The Hyper-V page allocator functions are implemented in an architecture
neutral way.  Move them into the architecture neutral VMbus module so
a separate implementation for ARM64 is not needed.

No functional change.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/1614721102-2241-2-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08 17:32:59 +00:00
Linus Torvalds
8b83369ddc Merge tag 'riscv-for-linus-5.12-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt:
 "A handful of new RISC-V related patches for this merge window:

   - A check to ensure drivers are properly using uaccess. This isn't
     manifesting with any of the drivers I'm currently using, but may
     catch errors in new drivers.

   - Some preliminary support for the FU740, along with the HiFive
     Unleashed it will appear on.

   - NUMA support for RISC-V, which involves making the arm64 code
     generic.

   - Support for kasan on the vmalloc region.

   - A handful of new drivers for the Kendryte K210, along with the DT
     plumbing required to boot on a handful of K210-based boards.

   - Support for allocating ASIDs.

   - Preliminary support for kernels larger than 128MiB.

   - Various other improvements to our KASAN support, including the
     utilization of huge pages when allocating the KASAN regions.

  We may have already found a bug with the KASAN_VMALLOC code, but it's
  passing my tests. There's a fix in the works, but that will probably
  miss the merge window.

* tag 'riscv-for-linus-5.12-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (75 commits)
  riscv: Improve kasan population by using hugepages when possible
  riscv: Improve kasan population function
  riscv: Use KASAN_SHADOW_INIT define for kasan memory initialization
  riscv: Improve kasan definitions
  riscv: Get rid of MAX_EARLY_MAPPING_SIZE
  soc: canaan: Sort the Makefile alphabetically
  riscv: Disable KSAN_SANITIZE for vDSO
  riscv: Remove unnecessary declaration
  riscv: Add Canaan Kendryte K210 SD card defconfig
  riscv: Update Canaan Kendryte K210 defconfig
  riscv: Add Kendryte KD233 board device tree
  riscv: Add SiPeed MAIXDUINO board device tree
  riscv: Add SiPeed MAIX GO board device tree
  riscv: Add SiPeed MAIX DOCK board device tree
  riscv: Add SiPeed MAIX BiT board device tree
  riscv: Update Canaan Kendryte K210 device tree
  dt-bindings: add resets property to dw-apb-timer
  dt-bindings: fix sifive gpio properties
  dt-bindings: update sifive uart compatible string
  dt-bindings: update sifive clint compatible string
  ...
2021-02-26 10:28:35 -08:00
Linus Torvalds
2bd3f4eeb3 Merge tag 'orphan-handling-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull orphan handling fix from Kees Cook:
 "Another case of bogus .eh_frame emission was noticed under
  CONFIG_GCOV_KERNEL=y.

  Summary:

   - Define SANITIZER_DISCARDS with CONFIG_GCOV_KERNEL=y (Nathan
     Chancellor)"

* tag 'orphan-handling-v5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  vmlinux.lds.h: Define SANITIZER_DISCARDS with CONFIG_GCOV_KERNEL=y
2021-02-26 10:12:19 -08:00
Nathan Chancellor
f5b6a74d9c vmlinux.lds.h: Define SANTIZER_DISCARDS with CONFIG_GCOV_KERNEL=y
clang produces .eh_frame sections when CONFIG_GCOV_KERNEL is enabled,
even when -fno-asynchronous-unwind-tables is in KBUILD_CFLAGS:

$ make CC=clang vmlinux
...
ld: warning: orphan section `.eh_frame' from `init/main.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/version.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/do_mounts.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/do_mounts_initrd.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/initramfs.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/calibrate.o' being placed in section `.eh_frame'
ld: warning: orphan section `.eh_frame' from `init/init_task.o' being placed in section `.eh_frame'
...

$ rg "GCOV_KERNEL|GCOV_PROFILE_ALL" .config
CONFIG_GCOV_KERNEL=y
CONFIG_ARCH_HAS_GCOV_PROFILE_ALL=y
CONFIG_GCOV_PROFILE_ALL=y

This was already handled for a couple of other options in
commit d812db7828 ("vmlinux.lds.h: Avoid KASAN and KCSAN's unwanted
sections") and there is an open LLVM bug for this issue. Take advantage
of that section for this config as well so that there are no more orphan
warnings.

Link: https://bugs.llvm.org/show_bug.cgi?id=46478
Link: https://github.com/ClangBuiltLinux/linux/issues/1069
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Fixes: d812db7828 ("vmlinux.lds.h: Avoid KASAN and KCSAN's unwanted sections")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210130004650.2682422-1-nathan@kernel.org
2021-02-25 13:15:25 -08:00