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Mateusz Guzik c8afaa1b0f locking: remove spin_lock_prefetch 
The only remaining consumer is new_inode, where it showed up in 2001 as
commit c37fa164f793 ("v2.4.9.9 -> v2.4.9.10") in a historical repo [1]
with a changelog which does not mention it.

Since then the line got only touched up to keep compiling.

While it may have been of benefit back in the day, it is guaranteed to
at best not get in the way in the multicore setting -- as the code
performs *a lot* of work between the prefetch and actual lock acquire,
any contention means the cacheline is already invalid by the time the
routine calls spin_lock().  It adds spurious traffic, for short.

On top of it prefetch is notoriously tricky to use for single-threaded
purposes, making it questionable from the get go.

As such, remove it.

I admit upfront I did not see value in benchmarking this change, but I
can do it if that is deemed appropriate.

Removal from new_inode and of the entire thing are in the same patch as
requested by Linus, so whatever weird looks can be directed at that guy.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/fs/inode.c?id=c37fa164f793735b32aa3f53154ff1a7659e6442 [1]
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 		2023-08-12 09:18:47 -07:00
..
dec MIPS: dec: prom: Address -Warray-bounds warning 2023-06-23 15:00:29 +02:00
fw add intptr_t 2023-06-09 17:44:13 -07:00
ip32
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mach-ar7 MIPS: AR7: remove orphan declarations from arch/mips/include/asm/mach-ar7/ar7.h 2022-09-19 16:37:27 +02:00
mach-ath25 MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
mach-ath79 MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
mach-au1x00 gpiolib: remove unused gpio_cansleep() 2023-06-13 16:49:23 +02:00
mach-bcm47xx MIPS: BCM47XX: Add support for Huawei B593u-12 2023-03-14 17:05:14 +01:00
mach-bcm63xx PCI: Add defines for normal and subtractive PCI bridges 2022-02-17 15:29:35 -06:00
mach-bmips
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mach-cavium-octeon locking: remove spin_lock_prefetch 2023-08-12 09:18:47 -07:00
mach-cobalt MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
mach-db1x00
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mach-dec MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
mach-generic MIPS: Remove no longer used ide.h 2023-04-05 10:08:51 +02:00
mach-ingenic MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
mach-ip22 MIPS: Remove mach-*/war.h 2020-09-07 22:25:27 +02:00
mach-ip27 MIPS: IP27: Remove incorrect `cpu_has_fpu' override 2022-05-04 22:23:14 +02:00
mach-ip28 MIPS: SGI-IP28: disable use of ll/sc in kernel 2020-10-08 10:33:27 +02:00
mach-ip30 MIPS: IP30: Remove incorrect `cpu_has_fpu' override 2022-05-04 22:23:18 +02:00
mach-ip32 MIPS: Remove mach-*/war.h 2020-09-07 22:25:27 +02:00
mach-jazz
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mach-lantiq MIPS: lantiq: remove unused function declaration 2023-04-05 10:21:06 +02:00
mach-loongson2ef MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
mach-loongson32 - added support for TP-Link HC220 G5 v1 2023-06-29 15:01:51 -07:00
mach-loongson64 irqchip/loongson-liointc: Add ACPI init support 2022-07-20 12:09:21 +01:00
mach-malta MIPS: malta: remove mach-malta/malta-dtshim.h header file 2020-09-21 22:16:47 +02:00
mach-n64 mips: Add N64 machine type 2021-01-22 11:40:00 +01:00
mach-pic32
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mach-ralink mips: ralink: mt7620: remove clock related code 2023-06-21 14:50:23 +02:00
mach-rc32434 MIPS: Fix a compilation issue 2023-01-27 17:22:06 +01:00
mach-rm MIPS: Remove mach-*/war.h 2020-09-07 22:25:27 +02:00
mach-sibyte MIPS: Remove mach-*/war.h 2020-09-07 22:25:27 +02:00
mach-tx49xx MIPS: TXX9: Remove rbtx4939 board support 2022-01-02 14:10:40 +01:00
mips-boards MIPS: launch.h: add include guard to prevent build errors 2021-05-25 15:18:59 +02:00
octeon staging: octeon: cvmx_ptr_to_phys() should return physaddr_t 2022-11-02 08:21:49 +01:00
pci
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sgi MIPS: SGI-IP30: Move irq bits to better header files 2020-09-21 22:15:49 +02:00
sibyte MIPS: sibyte: Remove Sibyte CARMEL and CRHINE board support 2023-03-17 10:27:21 +01:00
sn MIPS: remove define-only GDA_MAGIC, previously magic number 2022-09-24 14:17:18 +02:00
txx9 MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
vdso MIPS: vdso: Invalid GIC access through VDSO 2021-07-09 15:29:06 +02:00
xtalk
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Kbuild mips: syscalls: switch to generic syscalltbl.sh 2021-03-10 15:19:14 +01:00
abi.h
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addrspace.h
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amon.h
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arch_hweight.h
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asm-eva.h
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asm-offsets.h
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asm-prototypes.h MIPS: Restore symbol versions for copy_page_cpu and clear_page_cpu 2022-12-01 11:46:05 +01:00
asm.h MIPS: Workaround clang inline compat branch issue 2023-02-28 23:09:49 +01:00
asmmacro-32.h MIPS: Always use -Wa,-msoft-float and eliminate GAS_HAS_SET_HARDFLOAT 2023-01-26 12:41:16 +09:00
asmmacro-64.h
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asmmacro.h MIPS: Drop unused positional parameter in local_irq_{dis,en}able 2023-04-05 10:20:00 +02:00
atomic.h locking/atomic: make atomic*_{cmp,}xchg optional 2023-06-05 09:57:14 +02:00
barrier.h
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bcache.h
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bitops.h bitmap patches for 5.17-rc1 2022-01-23 06:20:44 +02:00
bitrev.h
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bmips-spaces.h
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bmips.h
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bootinfo.h MIPS: Ingenic: Add system type for new Ingenic SoCs. 2021-07-19 13:16:42 +02:00
branch.h
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break.h
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bug.h
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bugs.h mips/cpu: Switch to arch_cpu_finalize_init() 2023-06-16 10:16:00 +02:00
cache.h MIPS: Move declaration of bcache ops to cache.c 2023-04-05 09:45:08 +02:00
cacheflush.h MIPS: mm: Remove local_cache_flush_page 2023-04-05 10:08:53 +02:00
cacheops.h
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cdmm.h
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cevt-r4k.h
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checksum.h MIPS: Rewrite `csum_tcpudp_nofold' in plain C 2022-05-23 11:29:59 +02:00
clocksource.h
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cmp.h
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cmpxchg.h locking/arch: Rename all internal __xchg() names to __arch_xchg() 2023-04-29 09:08:44 +02:00
compat-signal.h
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compat.h asm-generic: compat: Cleanup duplicate definitions 2022-04-26 13:35:54 -07:00
compiler.h MIPS: remove GCC < 4.9 support 2020-11-11 23:49:22 +01:00
cop2.h MIPS: Remove NETLOGIC support 2021-10-24 17:24:47 +02:00
cpu-features.h MIPS: cpu-features: Use boot_cpu_type for CPU type based features 2023-06-09 09:56:22 +02:00
cpu-info.h
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cpu-type.h MIPS: Remove VR41xx support 2022-07-14 11:52:29 +02:00
cpu.h MIPS: Remove VR41xx support 2022-07-14 11:52:29 +02:00
cpufeature.h
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debug.h
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delay.h
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div64.h MIPS: Avoid handcoded DIVU in `__div64_32' altogether 2021-04-23 13:40:31 +02:00
dma-direct.h dma-direct: rename and cleanup __phys_to_dma 2020-09-11 09:14:43 +02:00
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 PCI: Move isa_dma_bridge_buggy out of asm/dma.h 2022-07-22 17:24:47 -05:00
dmi.h
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ds1287.h
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dsemul.h
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dsp.h
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edac.h
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elf.h mips compat: switch to compat_binfmt_elf.c 2021-01-06 08:42:49 -05:00
elfcore-compat.h mips compat: switch to compat_binfmt_elf.c 2021-01-06 08:42:49 -05:00
errno.h
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eva.h
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exec.h
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extable.h
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fb.h fbdev: Move framebuffer I/O helpers into <asm/fb.h> 2023-05-18 11:07:25 +02:00
fixmap.h mips: fix comment about pgtable_init() 2023-04-05 19:42:52 -07:00
floppy.h
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fpregdef.h MIPS: Always use -Wa,-msoft-float and eliminate GAS_HAS_SET_HARDFLOAT 2023-01-26 12:41:16 +09:00
fpu.h MIPS: Fix unreachable code issue 2021-07-13 15:08:15 -05:00
fpu_emulator.h
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ftrace.h MIPS: Fix build error due to PTR used in more places 2022-01-27 09:04:19 +01:00
futex.h MIPS: remove asm/war.h 2022-02-22 09:35:49 +01:00
ginvt.h MIPS: Avoid macro redefinitions 2021-09-23 11:23:35 +02:00
gio_device.h
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gt64120.h
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hardirq.h
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hazards.h MIPS: Remove NETLOGIC support 2021-10-24 17:24:47 +02:00
highmem.h MIPS: Fix PKMAP with 32-bit MIPS huge page support 2021-06-30 14:41:32 +02:00
hpet.h
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hugetlb.h mm: change huge_ptep_clear_flush() to return the original pte 2022-05-13 16:48:55 -07:00
hw_irq.h
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i8259.h
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idle.h MIPS: idle: Add prototype for function check_wait 2020-09-27 13:00:45 +02:00
inst.h MIPS: Make definitions of MIPSInst_FMA_{FUNC,FMTM} consistent with MIPS64 manual 2021-01-22 11:45:52 +01:00
io.h mips: provide unxlate_dev_mem_ptr() in asm/io.h 2023-06-09 09:48:53 +02:00
irq.h init: consolidate prototypes in linux/init.h 2023-06-09 17:44:16 -07:00
irq_cpu.h MIPS: Kill RM7K & RM9K IRQ Code 2021-01-04 11:37:27 +01:00
irq_gt641xx.h
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irq_regs.h
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irqflags.h mips: Implement arch_irqs_disabled() 2020-08-26 12:41:55 +02:00
isa-rev.h
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isadep.h MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
jazz.h
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jazzdma.h MIPS/jazzdma: remove the unused vdma_remap function 2020-09-11 08:13:49 +02:00
jump_label.h jump_label: make initial NOP patching the special case 2022-06-24 09:48:55 +02:00
kdebug.h
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kexec.h
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kgdb.h mips: kgdb: adjust the comment to the actual ifdef condition 2021-12-16 15:47:58 +01:00
kprobes.h
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kvm_host.h MIPS: KVM: Fix NULL pointer dereference 2023-07-03 16:06:19 +02:00
kvm_types.h
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linkage.h
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local.h locking/arch: Wire up local_try_cmpxchg() 2023-04-29 09:09:16 +02:00
maar.h
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machine.h treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
mc146818-time.h
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mc146818rtc.h
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mips-cm.h mips: cm: Convert to bitfield API to fix out-of-bounds access 2021-11-02 10:53:52 +01:00
mips-cpc.h
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mips-cps.h MIPS: CPS: Use bitfield helpers 2021-11-29 12:43:06 +01:00
mips-gic.h
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mips-r2-to-r6-emul.h
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mips_mt.h
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mipsmtregs.h MIPS: remove asm/war.h 2022-02-22 09:35:49 +01:00
mipsprom.h
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mipsregs.h MIPS: Always use -Wa,-msoft-float and eliminate GAS_HAS_SET_HARDFLOAT 2023-01-26 12:41:16 +09:00
mmiowb.h
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mmu.h
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mmu_context.h mips: use asm-generic/mmu_context.h for no-op implementations 2020-10-27 16:02:36 +01:00
mmzone.h mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA 2021-06-29 10:53:55 -07:00
module.h
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msa.h MIPS: Avoid macro redefinitions 2021-09-23 11:23:35 +02:00
msc01_ic.h
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paccess.h
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page.h mm, arch: add generic implementation of pfn_valid() for FLATMEM 2023-02-09 16:51:41 -08:00
pci.h PCI: Remove pci_get_legacy_ide_irq() and asm-generic/pci.h 2022-07-22 17:23:45 -05:00
perf_event.h
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pgalloc.h MIPS&LoongArch&NIOS2: adjust prototypes of p?d_init() 2022-12-11 18:12:11 -08:00
pgtable-32.h mips/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE 2023-02-02 22:33:08 -08:00
pgtable-64.h mips/mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE 2023-02-02 22:33:08 -08:00
pgtable-bits.h MIPS: Don't clear _PAGE_SPECIAL in _PAGE_CHG_MASK 2023-04-24 09:48:51 +02:00
pgtable.h mm: add PTE pointer parameter to flush_tlb_fix_spurious_fault() 2023-03-28 16:20:12 -07:00
pm-cps.h
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pm.h
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prefetch.h
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processor.h MIPS: Octeon: Allow CVMSEG to be disabled 2023-04-05 09:45:09 +02:00
prom.h MIPS: Fix wrong comments in asm/prom.h 2022-03-14 15:09:27 +01:00
ptrace.h Revert "MIPS: Add basic support for ptrace single step" 2021-02-18 11:57:44 +01:00
r4k-timer.h MIPS: Correct the header guard of r4k-timer.h 2020-09-18 15:29:00 +02:00
r4kcache.h MIPS: Fix build error due to PTR used in more places 2022-01-27 09:04:19 +01:00
reboot.h
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reg.h
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regdef.h
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rtlx.h MIPS: Remove deprecated CONFIG_MIPS_CMP 2023-04-12 15:01:09 +02:00
seccomp.h
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setup.h MIPS: fix fortify panic when copying asm exception handlers 2022-03-07 13:09:28 +01:00
sgialib.h
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sgiarcs.h
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shmparam.h
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sigcontext.h
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signal.h
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sim.h
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smp-cps.h MIPS: smp-cps: Don't rely on CP0_CMGCRBASE 2023-02-27 23:44:57 +01:00
smp-ops.h MIPS: SMP_CPS: Switch to hotplug core state synchronization 2023-05-15 13:44:58 +02:00
smp.h MIPS: Rework smt cmdline parameters 2023-06-09 10:34:14 +02:00
sni.h MIPS: remove orphan sni_cpu_time_init() declaration 2022-09-19 16:36:55 +02:00
socket.h
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sparsemem.h
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spinlock.h locking/arch: Move qrwlock.h include after qspinlock.h 2021-02-11 07:59:54 -05:00
spinlock_types.h
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spram.h MIPS: asm: spram: remove unneeded semicolon 2021-01-27 21:50:22 +01:00
stackframe.h MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
stackprotector.h stackprotector: actually use get_random_canary() 2022-11-18 02:18:10 +01:00
stacktrace.h
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string.h
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switch_to.h MIPS: context switch: Use save/restore instead of set/clear for Status.CU2 2020-09-21 22:14:47 +02:00
sync.h
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syscall.h mips: fix syscall_get_nr 2023-02-19 09:28:30 +01:00
thread_info.h MIPS: Only use current_stack_pointer on GCC 2022-03-14 15:02:53 +01:00
time.h
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timex.h mips: use fallback for random_get_entropy() instead of just c0 random 2022-05-13 23:59:23 +02:00
tlb.h
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tlbdebug.h
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tlbex.h
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tlbflush.h
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tlbmisc.h
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topology.h
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traps.h MIPS: Allow modules to set board_be_handler 2021-11-09 16:07:26 +01:00
txx9irq.h MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
txx9pio.h
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txx9tmr.h MIPS: Remove TX39XX support 2022-03-01 10:07:22 +01:00
types.h mips: Remove #include <uapi/asm/types.h> from <asm/types.h> 2020-11-11 23:45:46 +01:00
uaccess.h uaccess: generalize access_ok() 2022-02-25 09:36:05 +01:00
uasm.h mips, uasm: Add workaround for Loongson-2F nop CPU errata 2021-10-06 12:28:09 -07:00
unaligned-emul.h MIPS: Fix build error due to PTR used in more places 2022-01-27 09:04:19 +01:00
unistd.h fs: stat: compat: Add __ARCH_WANT_COMPAT_STAT 2022-04-26 13:35:45 -07:00
unroll.h
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uprobes.h
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vdso.h
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vermagic.h MIPS: Remove VR41xx support 2022-07-14 11:52:29 +02:00
vga.h
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vmalloc.h
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vpe.h MIPS: Remove deprecated CONFIG_MIPS_CMP 2023-04-12 15:01:09 +02:00
watch.h
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wbflush.h
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yamon-dt.h
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