diff options
Diffstat (limited to 'arch/x86/entry/calling.h')
| -rw-r--r-- | arch/x86/entry/calling.h | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 4208c1e3f601..5c0cbb443030 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -6,6 +6,7 @@ #include <asm/percpu.h> #include <asm/asm-offsets.h> #include <asm/processor-flags.h> +#include <asm/inst.h> /* @@ -351,3 +352,36 @@ For 32-bit we have the following conventions - kernel is built with call stackleak_erase #endif .endm + +#ifdef CONFIG_SMP + +/* + * CPU/node NR is loaded from the limit (size) field of a special segment + * descriptor entry in GDT. + */ +.macro LOAD_CPU_AND_NODE_SEG_LIMIT reg:req + movq $__CPUNODE_SEG, \reg + lsl \reg, \reg +.endm + +/* + * Fetch the per-CPU GSBASE value for this processor and put it in @reg. + * We normally use %gs for accessing per-CPU data, but we are setting up + * %gs here and obviously can not use %gs itself to access per-CPU data. + */ +.macro GET_PERCPU_BASE reg:req + ALTERNATIVE \ + "LOAD_CPU_AND_NODE_SEG_LIMIT \reg", \ + "RDPID \reg", \ + X86_FEATURE_RDPID + andq $VDSO_CPUNODE_MASK, \reg + movq __per_cpu_offset(, \reg, 8), \reg +.endm + +#else + +.macro GET_PERCPU_BASE reg:req + movq pcpu_unit_offsets(%rip), \reg +.endm + +#endif /* CONFIG_SMP */ |