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8f76f9c469
linux/include/asm-generic
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Vineet Gupta 8f76f9c469 bitops/non-atomic: make @nr unsigned to avoid any DIV 
signed math causes generation of costlier instructions such as DIV when
they could be done by barrerl shifter.

Worse part is this is not caught by things like bloat-o-meter since
instruction length / symbols are typically same size.

e.g.

stock (signed math)
__________________

919b4614 <test_taint>:
919b4614:	div	r2,r0,0x20
                ^^^
919b4618:	add2	r2,0x920f6050,r2
919b4620:	ld_s	r2,[r2,0]
919b4622:	lsr	r0,r2,r0
919b4626:	j_s.d	[blink]
919b4628:	bmsk_s	r0,r0,0
919b462a:	nop_s

(patched) unsigned math
__________________

919b4614 <test_taint>:
919b4614:	lsr	r2,r0,0x5  @nr/32
                ^^^
919b4618:	add2	r2,0x920f6050,r2
919b4620:	ld_s	r2,[r2,0]
919b4622:	lsr	r0,r2,r0     #test_bit()
919b4626:	j_s.d	[blink]
919b4628:	bmsk_s	r0,r0,0
919b462a:	nop_s

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2021-08-14 13:07:42 +02:00
..
bitops bitops/non-atomic: make @nr unsigned to avoid any DIV 2021-08-14 13:07:42 +02:00
vdso lib/vdso: Avoid highres update if clocksource is not VDSO capable 2020-02-17 20:12:17 +01:00
asm-offsets.h
asm-prototypes.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
atomic64.h locking/atomic: delete !ARCH_ATOMIC remnants 2021-05-26 13:20:52 +02:00
atomic-instrumented.h locking/atomics: atomic-instrumented: simplify ifdeffery 2021-05-26 13:20:52 +02:00
atomic-long.h asm-generic/atomic: Use __always_inline for pure wrappers 2020-01-07 07:47:23 -08:00
atomic.h locking/atomic: delete !ARCH_ATOMIC remnants 2021-05-26 13:20:52 +02:00
audit_change_attr.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
audit_dir_write.h audit: Avoid build failures on systems without renameat 2018-01-30 19:07:54 -08:00
audit_read.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
audit_signal.h
audit_write.h audit/stable-4.15 PR 20171113 2017-11-15 13:28:48 -08:00
barrier.h compiler.h: fix barrier_data() on clang 2020-11-14 11:26:03 -08:00
bitops.h asm-generic/bitops: Update stale comment 2020-03-06 11:06:19 +01:00
bitsperlong.h lib: extend the scope of small_const_nbits() macro 2021-05-06 19:24:11 -07:00
bug.h Merge branch 'akpm' (patches from Andrew) 2021-07-02 12:08:10 -07:00
bugs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cache.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cacheflush.h make asm-generic/cacheflush.h more standalone 2020-06-26 00:27:37 -07:00
checksum.h unify generic instances of csum_partial_copy_nocheck() 2020-08-20 15:45:14 -04:00
cmpxchg-local.h locking/atomic: cmpxchg: make generic a prefix 2021-05-26 13:20:50 +02:00
cmpxchg.h locking/atomic: delete !ARCH_ATOMIC remnants 2021-05-26 13:20:52 +02:00
compat.h compat: lift compat_s64 and compat_u64 to <asm-generic/compat.h> 2020-09-17 13:00:46 -04:00
current.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
delay.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
device.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
div64.h div64: Correct inline documentation for `do_div' 2021-04-21 13:45:36 +02:00
dma-mapping.h dma-mapping: bypass indirect calls for dma-direct 2018-12-13 21:06:18 +01:00
dma.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
early_ioremap.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
emergency-restart.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
error-injection.h treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
exec.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
export.h asm-generic: export: Stub EXPORT_SYMBOL with __DISABLE_EXPORTS 2021-02-03 16:42:57 +00:00
extable.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fb.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fixmap.h mm: introduce common STRUCT_PAGE_MAX_SHIFT define 2018-12-14 15:05:45 -08:00
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 generic arch_futex_atomic_op_inuser() doesn't need access_ok() 2020-03-27 23:58:55 -04:00
getorder.h asm-generic: force inlining of get_order() to work around gcc10 poor decision 2020-12-15 22:46:15 -08:00
gpio.h gpio: Avoid kernel.h inclusion where it's possible 2020-02-10 12:58:36 +01:00
hardirq.h irqstat: Move declaration into asm-generic/hardirq.h 2020-11-23 10:31:06 +01:00
hugetlb.h mm: Allow arches to provide ptep_get() 2020-06-20 22:14:53 +10:00
hw_irq.h
hyperv-tlfs.h asm-generic/hyperv: add HV_STATUS_ACCESS_DENIED definition 2021-06-17 13:09:38 -04:00
ide_iops.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
int-ll64.h int-ll64.h: define u{8,16,32,64} and s{8,16,32,64} based on uapi header 2018-06-07 17:34:38 -07:00
io.h mm: remove xlate_dev_kmem_ptr() 2021-05-07 00:26:34 -07:00
ioctl.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iomap.h asm-generic/io.h: Add a non-posted variant of ioremap() 2021-04-08 20:18:38 +09:00
irq_regs.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
irq_work.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irq.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
irqflags.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kbuild Rework of the X86 irq stack handling: 2021-02-24 16:32:23 -08:00
kdebug.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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: Introduce paravirtualization hints and KVM_HINTS_DEDICATED 2018-03-06 18:40:44 +01:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
local.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
logic_io.h lib: add iomem emulation (logic_iomem) 2021-06-17 21:44:51 +02:00
mcs_spinlock.h
memory_model.h mm: remove CONFIG_DISCONTIGMEM 2021-06-29 10:53:55 -07:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
module.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
module.lds.h kbuild: preprocess module linker script 2020-09-25 00:36:41 +09:00
mshyperv.h drivers: hv: Create a consistent pattern for checking Hyper-V hypercall status 2021-04-21 09:49:19 +00:00
msi.h Generic interrupt and irqchips subsystem: 2020-12-15 15:03:31 -08:00
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 c6x: remove architecture 2021-01-20 09:30:45 +01:00
param.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
parport.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
pci_iomap.h mn10300: Remove the architecture 2018-03-09 23:19:56 +01:00
pci.h PCI: remove PCI_DMA_BUS_IS_PHYS 2018-05-07 07:15:41 +02:00
percpu.h asm-generic: percpu: avoid Wshadow warning 2020-10-26 23:54:48 +00:00
pgalloc.h asm-generic: pgalloc.h: use correct #ifdef to enable pud_alloc_one() 2020-08-14 19:56:55 -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 mm: rename pud_page_vaddr to pud_pgtable and make it return pmd_t * 2021-07-08 11:48:22 -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 sched/core: Initialize the idle task with preemption disabled 2021-05-12 13:01:45 +02:00
qrwlock_types.h locking/qrwlock: include asm/byteorder.h as needed 2018-02-06 10:28:58 +01:00
qrwlock.h locking/arch: Move qrwlock.h include after qspinlock.h 2021-02-11 07:59:54 -05:00
qspinlock_types.h locking/qspinlock: Do not include atomic.h from qspinlock_types.h 2020-07-29 16:14:19 +02:00
qspinlock.h qspinlock: use signed temporaries for cmpxchg 2020-10-26 20:19:48 +01:00
resource.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
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 sections.h: dereference_function_descriptor() returns void pointer 2020-08-11 12:06:15 +02:00
serial.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
set_memory.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
shmparam.h treewide: remove SPDX "WITH Linux-syscall-note" from kernel-space headers 2019-05-14 19:52:48 -07:00
signal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
simd.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
softirq_stack.h softirq: Move do_softirq_own_stack() to generic asm header 2021-02-10 23:34:16 +01:00
spinlock.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
statfs.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
string.h
switch_to.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 36 2019-05-24 17:27:11 +02:00
syscall.h audit: Migrate to use SYSCALL_WORK flag 2020-11-16 21:53:16 +01:00
syscalls.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
termios-base.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
termios.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
timex.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tlb.h tlb: mmu_gather: Introduce tlb_gather_mmu_fullmm() 2021-01-29 20:02:29 +01:00
tlbflush.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
topology.h mm: replace CONFIG_NEED_MULTIPLE_NODES with CONFIG_NUMA 2021-06-29 10:53:55 -07:00
trace_clock.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
uaccess.h asm-generic: uaccess: remove inline strncpy_from_user/strnlen_user 2021-07-27 23:01:13 +02:00
unaligned.h asm-generic: simplify asm/unaligned.h 2021-05-17 13:30:29 +02:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
vmlinux.lds.h vmlinux.lds.h: Avoid orphan section with !SMP 2021-06-02 12:43:55 -07:00
vtime.h
word-at-a-time.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xor.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 47 2019-05-24 17:27:13 +02:00