Greg Kroah-Hartman
598cf27219
Link: https://lore.kernel.org/r/20260217200002.683975158@linuxfoundation.org Tested-by: Florian Fainelli <florian.fainelli@broadcom.com> Tested-by: Takeshi Ogasawara <takeshi.ogasawara@futuring-girl.com> Tested-by: Peter Schneider <pschneider1968@googlemail.com> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Salvatore Bonaccorso <carnil@debian.org> Tested-by: Brett A C Sheffield <bacs@librecast.net> Tested-by: Mark Brown <broonie@kernel.org> Tested-by: Luna Jernberg <droidbittin@gmail.com> Tested-by: Ronald Warsow <rwarsow@gmx.de> Tested-by: Justin M. Forbes <jforbes@fedoraproject.org> Tested-by: Ron Economos <re@w6rz.net> Tested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
46 lines
747 B
C
46 lines
747 B
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Fast user context implementation of getcpu()
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*/
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#include <asm/vdso.h>
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#include <linux/getcpu.h>
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static __always_inline int read_cpu_id(void)
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{
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int cpu_id;
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#ifdef CONFIG_64BIT
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__asm__ __volatile__(
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" rdtime.d $zero, %0\n"
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: "=r" (cpu_id)
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:
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: "memory");
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#else
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__asm__ __volatile__(
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" rdtimel.w $zero, %0\n"
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: "=r" (cpu_id)
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:
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: "memory");
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#endif
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return cpu_id;
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}
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extern
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int __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused);
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int __vdso_getcpu(unsigned int *cpu, unsigned int *node, struct getcpu_cache *unused)
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{
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int cpu_id;
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cpu_id = read_cpu_id();
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if (cpu)
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*cpu = cpu_id;
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if (node)
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*node = vdso_u_arch_data.pdata[cpu_id].node;
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return 0;
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}
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