mirror of
https://github.com/torvalds/linux.git
synced 2026-04-18 06:44:00 -04:00
7158fc54b2
The cache parameter of getcpu() is useless nowadays for various reasons. * It is never passed by userspace for either the vDSO or syscalls. * It is never used by the kernel. * It could not be made to work on the current vDSO architecture. * The structure definition is not part of the UAPI headers. * vdso_getcpu() is superseded by restartable sequences in any case. Remove the struct and its header. As a side-effect this gets rid of an unwanted inclusion of the linux/ header namespace from vDSO code. [ tglx: Adapt to s390 upstream changes */ Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@kernel.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Heiko Carstens <hca@linux.ibm.com> # s390 Link: https://patch.msgid.link/20251230-getcpu_cache-v3-1-fb9c5f880ebe@linutronix.de
45 lines
691 B
C
45 lines
691 B
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Fast user context implementation of getcpu()
|
|
*/
|
|
|
|
#include <asm/vdso.h>
|
|
|
|
static __always_inline int read_cpu_id(void)
|
|
{
|
|
int cpu_id;
|
|
|
|
#ifdef CONFIG_64BIT
|
|
__asm__ __volatile__(
|
|
" rdtime.d $zero, %0\n"
|
|
: "=r" (cpu_id)
|
|
:
|
|
: "memory");
|
|
#else
|
|
__asm__ __volatile__(
|
|
" rdtimel.w $zero, %0\n"
|
|
: "=r" (cpu_id)
|
|
:
|
|
: "memory");
|
|
#endif
|
|
|
|
return cpu_id;
|
|
}
|
|
|
|
extern
|
|
int __vdso_getcpu(unsigned int *cpu, unsigned int *node, void *unused);
|
|
int __vdso_getcpu(unsigned int *cpu, unsigned int *node, void *unused)
|
|
{
|
|
int cpu_id;
|
|
|
|
cpu_id = read_cpu_id();
|
|
|
|
if (cpu)
|
|
*cpu = cpu_id;
|
|
|
|
if (node)
|
|
*node = vdso_u_arch_data.pdata[cpu_id].node;
|
|
|
|
return 0;
|
|
}
|