linux/arch/x86/kernel/cpu/cpu.h
Pawan Gupta 95c5824f75 x86/cpu: Add a "tsx=" cmdline option with TSX disabled by default
Add a kernel cmdline parameter "tsx" to control the Transactional
Synchronization Extensions (TSX) feature. On CPUs that support TSX
control, use "tsx=on|off" to enable or disable TSX. Not specifying this
option is equivalent to "tsx=off". This is because on certain processors
TSX may be used as a part of a speculative side channel attack.

Carve out the TSX controlling functionality into a separate compilation
unit because TSX is a CPU feature while the TSX async abort control
machinery will go to cpu/bugs.c.

 [ bp: - Massage, shorten and clear the arg buffer.
       - Clarifications of the tsx= possible options - Josh.
       - Expand on TSX_CTRL availability - Pawan. ]

Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
2019-10-28 08:36:58 +01:00

84 lines
2.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef ARCH_X86_CPU_H
#define ARCH_X86_CPU_H
/* attempt to consolidate cpu attributes */
struct cpu_dev {
const char *c_vendor;
/* some have two possibilities for cpuid string */
const char *c_ident[2];
void (*c_early_init)(struct cpuinfo_x86 *);
void (*c_bsp_init)(struct cpuinfo_x86 *);
void (*c_init)(struct cpuinfo_x86 *);
void (*c_identify)(struct cpuinfo_x86 *);
void (*c_detect_tlb)(struct cpuinfo_x86 *);
int c_x86_vendor;
#ifdef CONFIG_X86_32
/* Optional vendor specific routine to obtain the cache size. */
unsigned int (*legacy_cache_size)(struct cpuinfo_x86 *,
unsigned int);
/* Family/stepping-based lookup table for model names. */
struct legacy_cpu_model_info {
int family;
const char *model_names[16];
} legacy_models[5];
#endif
};
struct _tlb_table {
unsigned char descriptor;
char tlb_type;
unsigned int entries;
/* unsigned int ways; */
char info[128];
};
#define cpu_dev_register(cpu_devX) \
static const struct cpu_dev *const __cpu_dev_##cpu_devX __used \
__attribute__((__section__(".x86_cpu_dev.init"))) = \
&cpu_devX;
extern const struct cpu_dev *const __x86_cpu_dev_start[],
*const __x86_cpu_dev_end[];
#ifdef CONFIG_CPU_SUP_INTEL
enum tsx_ctrl_states {
TSX_CTRL_ENABLE,
TSX_CTRL_DISABLE,
TSX_CTRL_NOT_SUPPORTED,
};
extern __ro_after_init enum tsx_ctrl_states tsx_ctrl_state;
extern void __init tsx_init(void);
extern void tsx_enable(void);
extern void tsx_disable(void);
#else
static inline void tsx_init(void) { }
#endif /* CONFIG_CPU_SUP_INTEL */
extern void get_cpu_cap(struct cpuinfo_x86 *c);
extern void get_cpu_address_sizes(struct cpuinfo_x86 *c);
extern void cpu_detect_cache_sizes(struct cpuinfo_x86 *c);
extern void init_scattered_cpuid_features(struct cpuinfo_x86 *c);
extern void init_intel_cacheinfo(struct cpuinfo_x86 *c);
extern void init_amd_cacheinfo(struct cpuinfo_x86 *c);
extern void init_hygon_cacheinfo(struct cpuinfo_x86 *c);
extern void detect_num_cpu_cores(struct cpuinfo_x86 *c);
extern int detect_extended_topology_early(struct cpuinfo_x86 *c);
extern int detect_extended_topology(struct cpuinfo_x86 *c);
extern int detect_ht_early(struct cpuinfo_x86 *c);
extern void detect_ht(struct cpuinfo_x86 *c);
unsigned int aperfmperf_get_khz(int cpu);
extern void x86_spec_ctrl_setup_ap(void);
extern u64 x86_read_arch_cap_msr(void);
#endif /* ARCH_X86_CPU_H */