diff options
Diffstat (limited to 'arch/x86/machine/cpu.h')
| -rw-r--r-- | arch/x86/machine/cpu.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/arch/x86/machine/cpu.h b/arch/x86/machine/cpu.h index 14ed73cb..4413c61f 100644 --- a/arch/x86/machine/cpu.h +++ b/arch/x86/machine/cpu.h @@ -204,6 +204,11 @@ struct cpu_tss { } __packed; /* + * Forward declaration. + */ +struct tcb; + +/* * CPU states. */ #define CPU_STATE_OFF 0 @@ -217,6 +222,7 @@ struct cpu_tss { struct cpu { struct cpu *self; + struct tcb *tcb; unsigned int id; unsigned int apic_id; char vendor_id[CPU_VENDOR_ID_SIZE]; @@ -419,6 +425,28 @@ cpu_current(void) return cpu; } +/* + * The current TCB must be obtained and updated in a migration-safe way. + */ +static __always_inline struct tcb * +cpu_tcb(void) +{ + struct tcb *tcb; + + asm volatile("mov %%fs:%1, %0" + : "=r" (tcb) + : "m" (*(char *)offsetof(struct cpu, tcb))); + + return tcb; +} + +static __always_inline void +cpu_set_tcb(struct tcb *tcb) +{ + asm volatile("mov %0, %%fs:%1" + : : "r" (tcb), "m" (*(char *)offsetof(struct cpu, tcb))); +} + static __always_inline unsigned int cpu_id(void) { |