From 4e62566c48df105bc8d4446444c93c461e6e6f2f Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Sun, 25 Sep 2022 17:28:38 +0200
Subject: [PATCH] Add with_value_of and with_value to MSR

---
 kernel/include/misc/MSR.h |  3 +++
 kernel/src/misc/MSR.cpp   | 15 +++++++++++++++
 2 files changed, 18 insertions(+)

diff --git a/kernel/include/misc/MSR.h b/kernel/include/misc/MSR.h
index aec5e03f..1c7ae4db 100644
--- a/kernel/include/misc/MSR.h
+++ b/kernel/include/misc/MSR.h
@@ -13,6 +13,9 @@ struct MSR
     static void write_to(uint32_t msr_num, uint64_t value);
     static uint64_t read_from(uint32_t msr_num);
 
+    static void with_value_of(uint32_t msr_num, void (*callback)(uint64_t&));
+    void with_value(void (*callback)(uint64_t&));
+
   private:
     uint32_t m_msr_num;
 };
\ No newline at end of file
diff --git a/kernel/src/misc/MSR.cpp b/kernel/src/misc/MSR.cpp
index a5813bf7..a4e412da 100644
--- a/kernel/src/misc/MSR.cpp
+++ b/kernel/src/misc/MSR.cpp
@@ -27,4 +27,19 @@ uint64_t MSR::read()
 
 MSR::MSR(uint32_t msr_num) : m_msr_num(msr_num)
 {
+}
+
+void MSR::with_value_of(uint32_t msr_num, void (*callback)(uint64_t&))
+{
+    MSR msr(msr_num);
+    uint64_t value = msr.read();
+    callback(value);
+    msr.write(value);
+}
+
+void MSR::with_value(void (*callback)(uint64_t&))
+{
+    uint64_t value = read();
+    callback(value);
+    write(value);
 }
\ No newline at end of file