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d2862bb9d9
The generic storage implementation provides the same features as the custom one. However it can be shared between architectures, making maintenance easier. Co-developed-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Nam Cao <namcao@linutronix.de> Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250204-vdso-store-rng-v3-10-13a4669dfc8c@linutronix.de
37 lines
631 B
C
37 lines
631 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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__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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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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