1 files changed, 56 insertions, 4 deletions

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index c7768269b1cf..c3429e8b2424 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -27,6 +27,7 @@ struct mm_struct;
 #include <linux/cpumask.h>
 #include <linux/cache.h>
 #include <linux/threads.h>
+#include <linux/math64.h>
 #include <linux/init.h>
 
 /*
@@ -403,7 +404,17 @@ extern unsigned long kernel_eflags;
 extern asmlinkage void ignore_sysret(void);
 #else	/* X86_64 */
 #ifdef CONFIG_CC_STACKPROTECTOR
-DECLARE_PER_CPU(unsigned long, stack_canary);
+/*
+ * Make sure stack canary segment base is cached-aligned:
+ *   "For Intel Atom processors, avoid non zero segment base address
+ *    that is not aligned to cache line boundary at all cost."
+ * (Optim Ref Manual Assembly/Compiler Coding Rule 15.)
+ */
+struct stack_canary {
+	char __pad[20];		/* canary at %gs:20 */
+	unsigned long canary;
+};
+DECLARE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
 #endif
 #endif	/* X86_64 */
 
@@ -703,13 +714,23 @@ static inline void cpu_relax(void)
 	rep_nop();
 }
 
-/* Stop speculative execution: */
+/* Stop speculative execution and prefetching of modified code. */
 static inline void sync_core(void)
 {
 	int tmp;
 
-	asm volatile("cpuid" : "=a" (tmp) : "0" (1)
-		     : "ebx", "ecx", "edx", "memory");
+#if defined(CONFIG_M386) || defined(CONFIG_M486)
+	if (boot_cpu_data.x86 < 5)
+		/* There is no speculative execution.
+		 * jmp is a barrier to prefetching. */
+		asm volatile("jmp 1f\n1:\n" ::: "memory");
+	else
+#endif
+		/* cpuid is a barrier to speculative execution.
+		 * Prefetched instructions are automatically
+		 * invalidated when modified. */
+		asm volatile("cpuid" : "=a" (tmp) : "0" (1)
+			     : "ebx", "ecx", "edx", "memory");
 }
 
 static inline void __monitor(const void *eax, unsigned long ecx,
@@ -1000,4 +1021,35 @@ extern void start_thread(struct pt_regs *regs, unsigned long new_ip,
 extern int get_tsc_mode(unsigned long adr);
 extern int set_tsc_mode(unsigned int val);
 
+extern int amd_get_nb_id(int cpu);
+
+struct aperfmperf {
+	u64 aperf, mperf;
+};
+
+static inline void get_aperfmperf(struct aperfmperf *am)
+{
+	WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_APERFMPERF));
+
+	rdmsrl(MSR_IA32_APERF, am->aperf);
+	rdmsrl(MSR_IA32_MPERF, am->mperf);
+}
+
+#define APERFMPERF_SHIFT 10
+
+static inline
+unsigned long calc_aperfmperf_ratio(struct aperfmperf *old,
+				    struct aperfmperf *new)
+{
+	u64 aperf = new->aperf - old->aperf;
+	u64 mperf = new->mperf - old->mperf;
+	unsigned long ratio = aperf;
+
+	mperf >>= APERFMPERF_SHIFT;
+	if (mperf)
+		ratio = div64_u64(aperf, mperf);
+
+	return ratio;
+}
+
 #endif /* _ASM_X86_PROCESSOR_H */