From 810a4e3515dd211ddec6ce8f0f9bc2d8131bbe5e Mon Sep 17 00:00:00 2001
From: Pawel Wieczorkiewicz <wipawel@amazon.de>
Date: Fri, 6 Aug 2021 10:44:31 +0200
Subject: [PATCH] x86 segment: add get_intr_handler() helper function

Add a helper function to retrieve offset field of an interrupt gate.

Signed-off-by: Pawel Wieczorkiewicz <wipawel@amazon.de>
---
 include/arch/x86/segment.h | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/include/arch/x86/segment.h b/include/arch/x86/segment.h
index 6deb4ffe..f04c0693 100644
--- a/include/arch/x86/segment.h
+++ b/include/arch/x86/segment.h
@@ -182,6 +182,10 @@ static inline void set_gate32_offset(struct x86_gate32 *gate, unsigned long offs
     gate->offset_hi = ((offset & _ul(0xffff0000)) >> 16);
 }
 
+static inline uint32_t get_gate32_offset(const struct x86_gate32 *gate) {
+    return (gate->offset_hi << 16) | gate->offset_lo;
+}
+
 static inline void set_gate32(struct x86_gate32 *gate, uint8_t type, uint16_t selector,
                               unsigned long offset, uint8_t dpl, bool present) {
     set_gate32_offset(gate, offset);
@@ -218,6 +222,10 @@ static inline void set_gate64_offset(struct x86_gate64 *gate, unsigned long offs
     gate->offset_hi = ((offset & _ul(0xffffffff00000000)) >> 32);
 }
 
+static inline uint64_t get_gate64_offset(const struct x86_gate64 *gate) {
+    return ((uint64_t) gate->offset_hi << 32) | (gate->offset_mi << 16) | gate->offset_lo;
+}
+
 static inline void set_gate64(struct x86_gate64 *gate, uint8_t type, uint16_t selector,
                               unsigned long offset, uint8_t dpl, bool present,
                               uint8_t ist) {
@@ -287,6 +295,9 @@ static inline void set_intr_gate(struct x86_gate32 *gate, uint16_t selector,
     set_gate32(gate, GATE_TYPE_INTR, selector, offset, dpl, present);
 }
 
+static inline uint32_t get_intr_handler(const struct x86_gate32 *gate) {
+    return get_gate32_offset(gate);
+}
 #else
 
 typedef struct x86_gate64 task_gate_t;
@@ -304,6 +315,10 @@ static inline void set_intr_gate(struct x86_gate64 *gate, uint16_t selector,
                                  uint8_t ist) {
     set_gate64(gate, GATE_TYPE_INTR, selector, offset, dpl, present, ist);
 }
+
+static inline uint64_t get_intr_handler(const struct x86_gate64 *gate) {
+    return get_gate64_offset(gate);
+}
 #endif
 
 extern idt_entry_t idt[256];