These changes are the raw update to linux-4.4.6-rt14. Kernel sources

[kvmfornfv.git] / kernel / arch / x86 / include / asm / mwait.h

diff --git a/kernel/arch/x86/include/asm/mwait.h b/kernel/arch/x86/include/asm/mwait.h
index 653dfa7..c70689b 100644 (file)
--- a/kernel/arch/x86/include/asm/mwait.h
+++ b/kernel/arch/x86/include/asm/mwait.h
@@ -14,6 +14,9 @@
 #define CPUID5_ECX_INTERRUPT_BREAK     0x2
 
 #define MWAIT_ECX_INTERRUPT_BREAK      0x1
+#define MWAITX_ECX_TIMER_ENABLE                BIT(1)
+#define MWAITX_MAX_LOOPS               ((u32)-1)
+#define MWAITX_DISABLE_CSTATES         0xf
 
 static inline void __monitor(const void *eax, unsigned long ecx,
                             unsigned long edx)
@@ -23,6 +26,14 @@ static inline void __monitor(const void *eax, unsigned long ecx,
                     :: "a" (eax), "c" (ecx), "d"(edx));
 }
 
+static inline void __monitorx(const void *eax, unsigned long ecx,
+                             unsigned long edx)
+{
+       /* "monitorx %eax, %ecx, %edx;" */
+       asm volatile(".byte 0x0f, 0x01, 0xfa;"
+                    :: "a" (eax), "c" (ecx), "d"(edx));
+}
+
 static inline void __mwait(unsigned long eax, unsigned long ecx)
 {
        /* "mwait %eax, %ecx;" */
@@ -30,6 +41,40 @@ static inline void __mwait(unsigned long eax, unsigned long ecx)
                     :: "a" (eax), "c" (ecx));
 }
 
+/*
+ * MWAITX allows for a timer expiration to get the core out a wait state in
+ * addition to the default MWAIT exit condition of a store appearing at a
+ * monitored virtual address.
+ *
+ * Registers:
+ *
+ * MWAITX ECX[1]: enable timer if set
+ * MWAITX EBX[31:0]: max wait time expressed in SW P0 clocks. The software P0
+ * frequency is the same as the TSC frequency.
+ *
+ * Below is a comparison between MWAIT and MWAITX on AMD processors:
+ *
+ *                 MWAIT                           MWAITX
+ * opcode          0f 01 c9           |            0f 01 fb
+ * ECX[0]                  value of RFLAGS.IF seen by instruction
+ * ECX[1]          unused/#GP if set  |            enable timer if set
+ * ECX[31:2]                     unused/#GP if set
+ * EAX                           unused (reserve for hint)
+ * EBX[31:0]       unused             |            max wait time (P0 clocks)
+ *
+ *                 MONITOR                         MONITORX
+ * opcode          0f 01 c8           |            0f 01 fa
+ * EAX                     (logical) address to monitor
+ * ECX                     #GP if not zero
+ */
+static inline void __mwaitx(unsigned long eax, unsigned long ebx,
+                           unsigned long ecx)
+{
+       /* "mwaitx %eax, %ebx, %ecx;" */
+       asm volatile(".byte 0x0f, 0x01, 0xfb;"
+                    :: "a" (eax), "b" (ebx), "c" (ecx));
+}
+
 static inline void __sti_mwait(unsigned long eax, unsigned long ecx)
 {
        trace_hardirqs_on();