linux/include/asm-generic
Linus Torvalds 125b0bb95d asm-generic: qspinlock: fix queued_spin_value_unlocked() implementation
We really don't want to do atomic_read() or anything like that, since we
already have the value, not the lock.  The whole point of this is that
we've loaded the lock from memory, and we want to check whether the
value we loaded was a locked one or not.

The main use of this is the lockref code, which loads both the lock and
the reference count in one atomic operation, and then works on that
combined value.  With the atomic_read(), the compiler would pointlessly
spill the value to the stack, in order to then be able to read it back
"atomically".

This is the qspinlock version of commit c6f4a90022 ("asm-generic:
ticket-lock: Optimize arch_spin_value_unlocked()") which fixed this same
bug for ticket locks.

Cc: Guo Ren <guoren@kernel.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Waiman Long <longman@redhat.com>
Link: https://lore.kernel.org/all/CAHk-=whNRv0v6kQiV5QO6DJhjH4KEL36vWQ6Re8Csrnh4zbRkQ@mail.gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-11-22 09:32:49 -08:00
..
bitops mm: delete checks for xor_unlock_is_negative_byte() 2023-10-18 14:34:17 -07:00
vdso lib/vdso: Avoid highres update if clocksource is not VDSO capable 2020-02-17 20:12:17 +01:00
access_ok.h uaccess: remove CONFIG_SET_FS 2022-02-25 09:36:06 +01:00
agp.h char/agp: introduce asm-generic/agp.h 2023-02-13 22:13:29 +01:00
archrandom.h random: handle archrandom with multiple longs 2022-07-25 13:26:14 +02:00
asm-offsets.h
asm-prototypes.h
atomic64.h locking/atomic: delete !ARCH_ATOMIC remnants 2021-05-26 13:20:52 +02:00
atomic.h locking/atomic: make atomic*_{cmp,}xchg optional 2023-06-05 09:57:14 +02:00
audit_change_attr.h
audit_dir_write.h
audit_read.h
audit_signal.h
audit_write.h
barrier.h asm-generic: Add memory barrier dma_mb() 2022-06-23 18:34:58 +01:00
bitops.h include: move find.h from asm_generic to linux 2022-01-15 08:47:31 -08:00
bitsperlong.h lib: extend the scope of small_const_nbits() macro 2021-05-06 19:24:11 -07:00
bug.h panic: make function declarations visible 2023-06-09 17:44:15 -07:00
cache.h
cacheflush.h mm: rationalise flush_icache_pages() and flush_icache_page() 2023-08-24 16:20:25 -07:00
checksum.h unify generic instances of csum_partial_copy_nocheck() 2020-08-20 15:45:14 -04:00
cmpxchg-local.h asm-generic: avoid __generic_cmpxchg_local warnings 2023-04-04 17:58:11 +02:00
cmpxchg.h asm-generic: avoid __generic_cmpxchg_local warnings 2023-04-04 17:58:11 +02:00
compat.h asm-generic: compat: fix compat_arg_u64() and compat_arg_u64_dual() 2022-11-01 10:20:11 +11:00
current.h asm-generic: current: Don't include thread-info.h if building asm 2023-08-26 22:38:49 +02:00
delay.h
device.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
div64.h ARM: 9117/1: asm-generic: div64: Remove always-true __div64_const32_is_OK() 2021-08-20 11:39:28 +01:00
dma-mapping.h dma-mapping: no need to pass a bus_type into get_arch_dma_ops() 2023-02-15 12:35:20 +01:00
dma.h
early_ioremap.h mm/early_ioremap.c: remove redundant early_ioremap_shutdown() 2021-09-08 11:50:24 -07:00
emergency-restart.h
error-injection.h docs: fault-injection: add requirements of error injectable functions 2023-02-02 22:50:00 -08:00
exec.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
export.h ia64,export.h: replace EXPORT_DATA_SYMBOL* with EXPORT_SYMBOL* 2023-06-22 21:21:06 +09:00
extable.h
fb.h fbdev: Replace fb_pgprotect() with pgprot_framebuffer() 2023-10-12 09:20:46 +02:00
fixmap.h
flat.h binfmt_flat: remove the persistent argument from flat_get_addr_from_rp 2019-06-24 09:16:47 +10:00
ftrace.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
futex.h futex: Fix additional regressions 2021-12-11 23:31:51 +01:00
getorder.h asm-generic: force inlining of get_order() to work around gcc10 poor decision 2020-12-15 22:46:15 -08:00
hardirq.h irqstat: Move declaration into asm-generic/hardirq.h 2020-11-23 10:31:06 +01:00
hugetlb.h mm: hugetlb: add huge page size param to set_huge_pte_at() 2023-09-29 17:20:47 -07:00
hw_irq.h
hyperv-tlfs.h x86/hyperv: Add smp support for SEV-SNP guest 2023-08-22 00:38:20 +00:00
int-ll64.h
io.h mm: ioremap: remove unneeded ioremap_allowed and iounmap_allowed 2023-08-18 10:12:36 -07:00
ioctl.h
iomap.h asm-generic/iomap.h: remove ARCH_HAS_IOREMAP_xx macros 2023-08-18 10:12:32 -07:00
irq_regs.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
irq_work.h
irq.h
irqflags.h
Kbuild asm-generic: Fix spelling of architecture 2023-10-06 22:30:22 +02:00
kdebug.h
kmap_size.h mm/highmem: Provide and use CONFIG_DEBUG_KMAP_LOCAL 2020-11-24 14:42:08 +01:00
kprobes.h treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
kvm_para.h
kvm_types.h KVM: Move x86's version of struct kvm_mmu_memory_cache to common code 2020-07-09 13:29:42 -04:00
linkage.h
local64.h locking/generic: Wire up local{,64}_try_cmpxchg() 2023-04-29 09:09:09 +02:00
local.h locking/generic: Wire up local{,64}_try_cmpxchg() 2023-04-29 09:09:09 +02:00
logic_io.h logic_io instance of iounmap() needs volatile on argument 2021-12-21 21:31:08 +01:00
mcs_spinlock.h
memory_model.h mm, arch: add generic implementation of pfn_valid() for FLATMEM 2023-02-09 16:51:41 -08:00
mm_hooks.h mm: remove arch_bprm_mm_init() hook 2020-01-23 10:41:16 -08:00
mmiowb_types.h asm-generic/mmiowb: Add generic implementation of mmiowb() tracking 2019-04-08 11:59:39 +01:00
mmiowb.h asm-generic/mmiowb: Allow mmiowb_set_pending() when preemptible() 2020-07-17 10:02:03 +01:00
mmu_context.h asm-generic: add generic MMU versions of mmu context functions 2020-10-26 16:45:03 +01:00
mmu.h
module.h
module.lds.h kbuild: preprocess module linker script 2020-09-25 00:36:41 +09:00
mshyperv.h hyperv: reduce size of ms_hyperv_info 2023-09-22 20:28:16 +00:00
msi.h genirq: Get rid of GENERIC_MSI_IRQ_DOMAIN 2022-11-17 15:15:20 +01:00
nommu_context.h asm-generic: add generic MMU versions of mmu context functions 2020-10-26 16:45:03 +01:00
numa.h numa: Move numa implementation to common code 2021-01-14 15:08:55 -08:00
page.h asm-generic/page.h: Make pfn accessors static inlines 2023-05-29 11:27:08 +02:00
param.h
parport.h
pci_iomap.h PCI: Stub __pci_ioport_map() for arches that don't support it at all 2022-07-29 12:01:00 -05:00
pci.h asm-generic: Add new pci.h and use it 2022-07-22 17:34:57 -05:00
percpu.h percpu: Fix self-assignment of __old in raw_cpu_generic_try_cmpxchg() 2023-06-08 10:28:39 +02:00
pgalloc.h mm: add statistics for PUD level pagetable 2023-10-06 14:44:10 -07:00
pgtable_uffd.h userfaultfd: wp: add pmd_swp_*uffd_wp() helpers 2020-04-07 10:43:39 -07:00
pgtable-nop4d.h mm: rename p4d_page_vaddr to p4d_pgtable and make it return pud_t * 2021-07-08 11:48:22 -07:00
pgtable-nopmd.h riscv/mm: fix two page table check related issues 2022-05-19 14:08:48 -07:00
pgtable-nopud.h mm: rename p4d_page_vaddr to p4d_pgtable and make it return pud_t * 2021-07-08 11:48:22 -07:00
preempt.h riscv: support PREEMPT_DYNAMIC with static keys 2023-08-31 00:18:34 -07:00
qrwlock_types.h locking/qrwlock: Change "queue rwlock" to "queued rwlock" 2022-05-11 16:27:04 +02:00
qrwlock.h asm-generic changes for 5.19 2022-05-26 10:50:30 -07:00
qspinlock_types.h locking/qspinlock: Do not include atomic.h from qspinlock_types.h 2020-07-29 16:14:19 +02:00
qspinlock.h asm-generic: qspinlock: fix queued_spin_value_unlocked() implementation 2023-11-22 09:32:49 -08:00
resource.h
rwonce.h asm/rwonce: Don't pull <asm/barrier.h> into 'asm-generic/rwonce.h' 2020-07-21 10:50:36 +01:00
seccomp.h seccomp: Use -1 marker for end of mode 1 syscall list 2020-07-10 16:01:52 -07:00
sections.h asm-generic: sections: refactor memory_intersects 2022-08-28 14:02:45 -07:00
serial.h
set_memory.h
shmparam.h treewide: remove SPDX "WITH Linux-syscall-note" from kernel-space headers 2019-05-14 19:52:48 -07:00
signal.h asm-generic: Remove empty #ifdef SA_RESTORER 2022-09-10 09:56:53 +02:00
simd.h
softirq_stack.h asm-generic: Conditionally enable do_softirq_own_stack() via Kconfig. 2022-09-05 17:20:55 +02:00
spinlock_types.h asm-generic: ticket-lock: New generic ticket-based spinlock 2022-05-11 11:49:38 -07:00
spinlock.h asm-generic: ticket-lock: Optimize arch_spin_value_unlocked() 2023-09-21 10:17:00 +02:00
statfs.h
string.h
switch_to.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
syscall.h ptrace: Create ptrace_report_syscall_{entry,exit} in ptrace.h 2022-03-10 13:35:08 -06:00
syscalls.h
timex.h
tlb.h mm: add utility functions for ptdesc 2023-08-21 13:37:52 -07:00
tlbflush.h
topology.h mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA 2021-06-29 10:53:55 -07:00
trace_clock.h
uaccess.h uaccess: remove CONFIG_SET_FS 2022-02-25 09:36:06 +01:00
unaligned.h asm-generic: make parameter types consistent in _unaligned_be48() 2022-09-11 21:55:12 -07:00
user.h
vermagic.h arch: split MODULE_ARCH_VERMAGIC definitions out to <asm/vermagic.h> 2020-04-23 10:50:26 +09:00
vga.h
vmlinux.lds.h linux/init: remove __memexit* annotations 2023-10-28 21:31:22 +09:00
vtime.h
word-at-a-time.h word-at-a-time: use the same return type for has_zero regardless of endianness 2023-08-02 10:23:36 -07:00
xor.h lib/xor: make xor prototypes more friendly to compiler vectorization 2022-02-11 20:39:39 +11:00