[patch V4 part 4 08/24] x86/entry: Provide IDTENTRY_IST

From: Thomas Gleixner
Date: Tue May 05 2020 - 10:19:31 EST


Same as IDTENTRY but for exceptions which run on Interrupt STacks (IST) on
64bit. For 32bit this maps to IDTENTRY.

There are 3 variants which will be used:
IDTENTRY_MCE
IDTENTRY_DB
IDTENTRY_NMI

These map to IDTENTRY_IST, but only the MCE and DB variants are emitting
ASM code as the NMI entry needs hand crafted ASM still.

The function defines do not contain any idtenter/exit calls as these
exceptions need special treatment.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>


---
arch/x86/include/asm/idtentry.h | 54 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 54 insertions(+)

--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -132,6 +132,42 @@ static __always_inline void __##func(str
#define DEFINE_IDTENTRY_RAW(func) \
__visible noinstr void func(struct pt_regs *regs)

+#ifdef CONFIG_X86_64
+/**
+ * DECLARE_IDTENTRY_IST - Declare functions for IST handling IDT entry points
+ * @vector: Vector number (ignored for C)
+ * @func: Function name of the entry point
+ *
+ * Maps to DECLARE_IDTENTRY_RAW
+ */
+#define DECLARE_IDTENTRY_IST(vector, func) \
+ DECLARE_IDTENTRY_RAW(vector, func)
+
+/**
+ * DEFINE_IDTENTRY_IST - Emit code for IST entry points
+ * @func: Function name of the entry point
+ *
+ * Maps to DEFINE_IDTENTRY_RAW
+ */
+#define DEFINE_IDTENTRY_IST(func) \
+ DEFINE_IDTENTRY_RAW(func)
+
+#else /* CONFIG_X86_64 */
+/* Maps to a regular IDTENTRY on 32bit for now */
+# define DECLARE_IDTENTRY_IST DECLARE_IDTENTRY
+# define DEFINE_IDTENTRY_IST DEFINE_IDTENTRY
+#endif /* !CONFIG_X86_64 */
+
+/* C-Code mapping */
+#define DECLARE_IDTENTRY_MCE DECLARE_IDTENTRY_IST
+#define DEFINE_IDTENTRY_MCE DEFINE_IDTENTRY_IST
+
+#define DECLARE_IDTENTRY_NMI DECLARE_IDTENTRY_IST
+#define DEFINE_IDTENTRY_NMI DEFINE_IDTENTRY_IST
+
+#define DECLARE_IDTENTRY_DEBUG DECLARE_IDTENTRY_IST
+#define DEFINE_IDTENTRY_DEBUG DEFINE_IDTENTRY_IST
+
#else /* !__ASSEMBLY__ */

/*
@@ -149,6 +185,24 @@ static __always_inline void __##func(str
#define DECLARE_IDTENTRY_RAW(vector, func) \
DECLARE_IDTENTRY(vector, func)

+#ifdef CONFIG_X86_64
+# define DECLARE_IDTENTRY_MCE(vector, func) \
+ idtentry_mce_db vector asm_##func func
+
+# define DECLARE_IDTENTRY_DEBUG(vector, func) \
+ idtentry_mce_db vector asm_##func func
+
+#else
+# define DECLARE_IDTENTRY_MCE(vector, func) \
+ DECLARE_IDTENTRY(vector, func)
+
+# define DECLARE_IDTENTRY_DEBUG(vector, func) \
+ DECLARE_IDTENTRY(vector, func)
+#endif
+
+/* No ASM code emitted for NMI */
+#define DECLARE_IDTENTRY_NMI(vector, func)
+
#endif /* __ASSEMBLY__ */

/*