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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2019-12-02 07:57:27 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-01-23 21:31:14 +1100 |
| commit | 902137ba8e469ed07c7f120a390161937a6288fb (patch) | |
| tree | 031cb524d3cd71a32efe368600dbc1c2d93b9117 | |
| parent | 8c452a889821ca0cd2a5f2e3e87fbc01e56408cb (diff) | |
| download | linux-902137ba8e469ed07c7f120a390161937a6288fb.tar.bz2 | |
powerpc/32: Add VDSO version of getcpu on non SMP
Commit 18ad51dd342a ("powerpc: Add VDSO version of getcpu") added
getcpu() for PPC64 only, by making use of a user readable general
purpose SPR.
PPC32 doesn't have any such SPR.
For non SMP, just return CPU id 0 from the VDSO directly.
PPC32 doesn't support CONFIG_NUMA so NUMA node is always 0.
Before the patch, vdsotest reported:
getcpu: syscall: 1572 nsec/call
getcpu: libc: 1787 nsec/call
getcpu: vdso: not tested
Now, vdsotest reports:
getcpu: syscall: 1582 nsec/call
getcpu: libc: 502 nsec/call
getcpu: vdso: 187 nsec/call
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/eaac4b6494ecff1811220fccc895bf282aab884a.1575273217.git.christophe.leroy@c-s.fr
| -rw-r--r-- | arch/powerpc/kernel/vdso32/Makefile | 4 | ||||
| -rw-r--r-- | arch/powerpc/kernel/vdso32/getcpu.S | 17 | ||||
| -rw-r--r-- | arch/powerpc/kernel/vdso32/vdso32.lds.S | 2 |
3 files changed, 19 insertions, 4 deletions
diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile index 06f54d947057..e147bbdc12cd 100644 --- a/arch/powerpc/kernel/vdso32/Makefile +++ b/arch/powerpc/kernel/vdso32/Makefile @@ -2,9 +2,7 @@ # List of files in the vdso, has to be asm only for now -obj-vdso32-$(CONFIG_PPC64) = getcpu.o -obj-vdso32 = sigtramp.o gettimeofday.o datapage.o cacheflush.o note.o \ - $(obj-vdso32-y) +obj-vdso32 = sigtramp.o gettimeofday.o datapage.o cacheflush.o note.o getcpu.o # Build rules diff --git a/arch/powerpc/kernel/vdso32/getcpu.S b/arch/powerpc/kernel/vdso32/getcpu.S index 63e914539e1a..90b39af14383 100644 --- a/arch/powerpc/kernel/vdso32/getcpu.S +++ b/arch/powerpc/kernel/vdso32/getcpu.S @@ -15,6 +15,7 @@ * int __kernel_getcpu(unsigned *cpu, unsigned *node); * */ +#if defined(CONFIG_PPC64) V_FUNCTION_BEGIN(__kernel_getcpu) .cfi_startproc mfspr r5,SPRN_SPRG_VDSO_READ @@ -31,3 +32,19 @@ V_FUNCTION_BEGIN(__kernel_getcpu) blr .cfi_endproc V_FUNCTION_END(__kernel_getcpu) +#elif !defined(CONFIG_SMP) +V_FUNCTION_BEGIN(__kernel_getcpu) + .cfi_startproc + cmpwi cr0, r3, 0 + cmpwi cr1, r4, 0 + li r5, 0 + beq cr0, 1f + stw r5, 0(r3) +1: li r3, 0 /* always success */ + crclr cr0*4+so + beqlr cr1 + stw r5, 0(r4) + blr + .cfi_endproc +V_FUNCTION_END(__kernel_getcpu) +#endif diff --git a/arch/powerpc/kernel/vdso32/vdso32.lds.S b/arch/powerpc/kernel/vdso32/vdso32.lds.S index 00c025ba4a92..5206c2eb2a1d 100644 --- a/arch/powerpc/kernel/vdso32/vdso32.lds.S +++ b/arch/powerpc/kernel/vdso32/vdso32.lds.S @@ -155,7 +155,7 @@ VERSION __kernel_sync_dicache_p5; __kernel_sigtramp32; __kernel_sigtramp_rt32; -#ifdef CONFIG_PPC64 +#if defined(CONFIG_PPC64) || !defined(CONFIG_SMP) __kernel_getcpu; #endif |