From 5fc386102380e6c15c81df4fd750f54641535eaa Mon Sep 17 00:00:00 2001
From: Ada Christine <adachristine18@gmail.com>
Date: Tue, 15 Feb 2022 15:00:53 +0000
Subject: beginning to things out into cpu-dependent and cpu-independent code

---
 kc/core/cpu/irq.c | 24 ++++++++++++++++++++++++
 kc/core/cpu/irq.h |  4 ++++
 kc/core/cpu/mmu.c | 30 ++++++++++++++++++++++++++++++
 kc/core/cpu/mmu.h |  9 +++++++++
 4 files changed, 67 insertions(+)
 create mode 100644 kc/core/cpu/irq.c
 create mode 100644 kc/core/cpu/mmu.c
 create mode 100644 kc/core/cpu/mmu.h

(limited to 'kc/core/cpu')

diff --git a/kc/core/cpu/irq.c b/kc/core/cpu/irq.c
new file mode 100644
index 0000000..639aca3
--- /dev/null
+++ b/kc/core/cpu/irq.c
@@ -0,0 +1,24 @@
+#include "irq.h"
+
+#include <stdatomic.h>
+
+static atomic_uint_fast64_t irq_lock_count = 0;
+
+void irq_lock(void)
+{
+    __asm__ volatile ("cli;");
+}
+
+void irq_unlock(void)
+{
+    if (irq_lock_count >= 1)
+    {
+        irq_lock_count--;
+    }
+
+    if (irq_lock_count == 0)
+    {
+        __asm__ volatile ("sti;");
+    }
+}
+
diff --git a/kc/core/cpu/irq.h b/kc/core/cpu/irq.h
index 9874761..9734860 100644
--- a/kc/core/cpu/irq.h
+++ b/kc/core/cpu/irq.h
@@ -3,6 +3,10 @@
 #include "interrupt.h"
 
 #ifndef __ASSEMBLER__
+
+void irq_lock(void);
+void irq_unlock(void);
+
 #else
 
 .macro IRQ_DECLARE name:req handler:req, irq:req, offset:req
diff --git a/kc/core/cpu/mmu.c b/kc/core/cpu/mmu.c
new file mode 100644
index 0000000..60bee0f
--- /dev/null
+++ b/kc/core/cpu/mmu.c
@@ -0,0 +1,30 @@
+#include "mmu.h"
+#include "irq.h"
+
+#include <kernel/memory/paging.h>
+
+void mmu_set_map(phys_addr_t map)
+{
+    irq_lock();
+    __asm__ volatile ("mov %0, %%cr3" :: "r"(page_address(map, 1)));
+    irq_unlock();
+}
+
+phys_addr_t mmu_get_map(void)
+{
+    phys_addr_t pm4_phys;
+    irq_lock();
+    __asm__ volatile
+        (
+         "mov %%cr3, %0\n\t"
+         : "=r"(pm4_phys)
+        );
+    irq_unlock();
+    return page_address(pm4_phys, 1);
+}
+
+void mmu_invalidate(void *addr)
+{
+    __asm__ volatile ("invlpg (%0)" :: "r"(addr));
+}
+
diff --git a/kc/core/cpu/mmu.h b/kc/core/cpu/mmu.h
new file mode 100644
index 0000000..2021a2e
--- /dev/null
+++ b/kc/core/cpu/mmu.h
@@ -0,0 +1,9 @@
+#pragma once
+
+#include "memory.h"
+
+void mmu_set_map(phys_addr_t map);
+phys_addr_t mmu_get_map(void);
+
+void mmu_invalidate(void *addr);
+
-- 
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