From db8a61a779cd3192b451931ce8b41bd41d73f91a Mon Sep 17 00:00:00 2001
From: Alex Kotov <kotovalexarian@gmail.com>
Date: Wed, 25 Nov 2020 17:03:33 +0500
Subject: [PATCH] Remove page frame allocator

---
 kernelmq/Makefile |   1 -
 kernelmq/init.c   |   3 --
 kernelmq/pfa.c    | 111 ----------------------------------------------
 kernelmq/pfa.h    |  14 ------
 4 files changed, 129 deletions(-)
 delete mode 100644 kernelmq/pfa.c
 delete mode 100644 kernelmq/pfa.h

diff --git a/kernelmq/Makefile b/kernelmq/Makefile
index 33db017..4666384 100644
--- a/kernelmq/Makefile
+++ b/kernelmq/Makefile
@@ -14,7 +14,6 @@ OBJS += main.c.o
 OBJS += init.c.o
 OBJS += multiboot.c.o
 OBJS += panic.c.o  panic.asm.cpp.o
-OBJS += pfa.c.o
 OBJS += paging.c.o paging.asm.cpp.o
 OBJS += pagedir.c.o
 
diff --git a/kernelmq/init.c b/kernelmq/init.c
index 8d0463c..5abdde3 100644
--- a/kernelmq/init.c
+++ b/kernelmq/init.c
@@ -1,5 +1,4 @@
 #include "panic.h"
-#include "pfa.h"
 #include "protected.h"
 #include "paging.h"
 
@@ -19,8 +18,6 @@ void init(const struct KernelMQ_Info *const kinfo_ptr)
 
     assert(kernelmq_info_validate_and_copy(&kinfo, kinfo_ptr), "Invalid kernel information.");
 
-    pfa_initialize(&kinfo);
-
     protected_initialize(&kinfo);
 
     // Set up a new post-relocate bootstrap pagetable so that
diff --git a/kernelmq/pfa.c b/kernelmq/pfa.c
deleted file mode 100644
index d9c74c1..0000000
--- a/kernelmq/pfa.c
+++ /dev/null
@@ -1,111 +0,0 @@
-#include "pfa.h"
-
-#include "config.h"
-#include "panic.h"
-#include "logger.h"
-
-#include "stdlib.h"
-
-#define FRAMES_COUNT (PAGE_DIR_LENGTH * PAGE_TABLE_LENGTH)
-
-static unsigned char frames[FRAMES_COUNT];
-
-static void mark_used(unsigned long base, unsigned long limit);
-
-void pfa_initialize(const struct KernelMQ_Info *const kinfo)
-{
-    logger_info_from("pfa", "Initialize page frame allocator.");
-
-    kmemset(frames, 0, sizeof(frames));
-
-    mark_used(0, MEM_UPPER_BASE - 1);
-
-    mark_used(kinfo->kernel_phys_base, kinfo->kernel_phys_limit);
-
-    for (unsigned int i = 0; i < kinfo->modules_count; ++i) {
-        const struct KernelMQ_Info_Module *const module = &kinfo->modules[i];
-
-        mark_used(module->base, module->limit);
-    }
-
-    for (unsigned int i = 0; i < kinfo->areas_count; ++i) {
-        const struct KernelMQ_Info_Area *const area = &kinfo->areas[i];
-
-        if (!area->is_available) {
-            mark_used(area->base, area->limit);
-        }
-    }
-}
-
-unsigned long pfa_alloc_page()
-{
-    for (unsigned int i = 0; i < FRAMES_COUNT; ++i) {
-        if (!frames[i]) {
-            frames[i] = 0xFF;
-            return i * PAGE_SIZE;
-        }
-    }
-
-    return 0;
-}
-
-unsigned long pfa_alloc_big_page()
-{
-    unsigned int start = 0;
-
-    for (unsigned int i = 0; i < FRAMES_COUNT; ++i) {
-        if (frames[i]) {
-            start = i + 1;
-            continue;
-        }
-
-        if (start % (PAGE_BIG_SIZE / PAGE_SIZE)) {
-            continue;
-        }
-
-        if (i - start + 1 == PAGE_BIG_SIZE / PAGE_SIZE) {
-            for (unsigned int j = start; j <= i; ++j) {
-                frames[j] = 0xFF;
-            }
-
-            return start * PAGE_SIZE;
-        }
-    }
-
-    return 0;
-}
-
-void pfa_free_page(const unsigned long base)
-{
-    assert(!(base % PAGE_SIZE), "Small page address to free is not aligned.");
-
-    const unsigned long i = base / PAGE_SIZE;
-
-    if (i >= FRAMES_COUNT) {
-        return;
-    }
-
-    frames[i] = 0;
-}
-
-void pfa_free_big_page(const unsigned long base)
-{
-    assert(!(base % PAGE_BIG_SIZE), "Big page address to free is not aligned.");
-
-    const unsigned long start = base / PAGE_SIZE;
-    const unsigned long end   = start + PAGE_BIG_SIZE / PAGE_SIZE;
-
-    for (unsigned int i = start; i <= end && i < FRAMES_COUNT; ++i) {
-        frames[i] = 0;
-    }
-}
-
-void mark_used(const unsigned long base, const unsigned long limit)
-{
-    const unsigned int start = base  / PAGE_SIZE;
-    const unsigned int end   = limit / PAGE_SIZE;
-
-    for (unsigned int i = start; i <= end; ++i) {
-        frames[i] = 0xFF;
-    }
-}
diff --git a/kernelmq/pfa.h b/kernelmq/pfa.h
deleted file mode 100644
index 70526b3..0000000
--- a/kernelmq/pfa.h
+++ /dev/null
@@ -1,14 +0,0 @@
-#ifndef KERNELMQ_INCLUDED_PFA
-#define KERNELMQ_INCLUDED_PFA 1
-
-#include "info.h"
-
-void pfa_initialize(const struct KernelMQ_Info *kinfo);
-
-unsigned long pfa_alloc_page();
-unsigned long pfa_alloc_big_page();
-
-void pfa_free_page(unsigned long base);
-void pfa_free_big_page(unsigned long base);
-
-#endif