From 0bc304328dbd534e4f1fee40fb161a67b143d40d Mon Sep 17 00:00:00 2001
From: josh <josh@5b3e749e-e535-0410-8002-a9bb6afbdfca>
Date: Fri, 22 Jan 2010 20:51:34 +0000
Subject: [PATCH] kernel now keeping track of total/free number of physical
 pages instead of free/used

git-svn-id: svn://anubis/hos/trunk@90 5b3e749e-e535-0410-8002-a9bb6afbdfca
---
 kernel/mm/mm.cc | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/kernel/mm/mm.cc b/kernel/mm/mm.cc
index 2079ae3..1a81c86 100644
--- a/kernel/mm/mm.cc
+++ b/kernel/mm/mm.cc
@@ -14,7 +14,7 @@ static pagedirectory_entry_t * page_directory;
 static mm_mem_range_t mm_mmap_entries[MM_MAX_MMAP_ENTRIES];
 static int mm_mmap_num_entries = 0;
 static int mm_num_free_pages = 0;
-static int mm_num_used_pages = 0;
+static int mm_num_total_pages = 0;
 static u32_t * mm_free_page_ptr = NULL;
 gdtr_t mm_gdtr;
 static u64_t * mm_gdt;
@@ -47,6 +47,11 @@ void mm_record_mmap_entry(mb_mmap_t * mmap)
 void mm_bootstrap()
 {
     u32_t max_ram_address = KERNEL_PHYSICAL_ADDRESS + KERNEL_SIZE - 1;
+    /* this function requires a big enough initial stack to run */
+    BUILD_BUG_ON((STACK_INITIAL_SIZE * PAGE_SIZE) < 8000);
+    u32_t page_alloc_pages[1025];
+    u32_t num_page_alloc_pages = 0;
+    mm_free_page_ptr = NULL;
 
     if (mm_mmap_num_entries < 1)
     {
@@ -57,6 +62,7 @@ void mm_bootstrap()
     {
         u32_t base_address = mm_mmap_entries[mmap_idx].base;
         u32_t address_limit = base_address + mm_mmap_entries[mmap_idx].length;
+
         if (base_address & PAGE_LOW_MASK)
         {
             /* start of this mmap range is not page-aligned */
@@ -78,8 +84,9 @@ void mm_bootstrap()
          * loop through every page in the mmap range and add
          * pages into the free page linked list
          */
-        u32_t * last_page = NULL;
-        while (base_address < address_limit)
+        for (u32_t * last_page = NULL;
+             base_address < address_limit;
+             base_address += PAGE_SIZE)
         {
             /* check to make sure the RAM page is ok */
             if (   base_address > 0     /* don't map address 0 */
@@ -101,7 +108,7 @@ void mm_bootstrap()
                 last_page = page_virtual_address;
                 mm_num_free_pages++;
             }
-            base_address += PAGE_SIZE;
+            mm_num_total_pages++;
         }
     }
 
@@ -266,7 +273,6 @@ u32_t mm_early_page_alloc()
         page_address = (u32_t) mm_free_page_ptr;
         mm_free_page_ptr = (u32_t *) *page_ptr;
         mm_num_free_pages--;
-        mm_num_used_pages++;
     }
     return page_address;
 }
@@ -284,7 +290,6 @@ u32_t mm_page_alloc()
         page_address = (u32_t) mm_free_page_ptr;
         mm_free_page_ptr = (u32_t *) *page_ptr;
         mm_num_free_pages--;
-        mm_num_used_pages++;
     }
     return page_address;
 }
@@ -302,6 +307,6 @@ void mm_print_memory_map()
                 mm_mmap_entries[i].length >> 10,
                 mm_mmap_entries[i].length >> 20);
     }
-    kprintf("Used pages: %d\n", mm_num_used_pages);
+    kprintf("Used pages: %d\n", mm_num_total_pages - mm_num_free_pages);
     kprintf("Free pages: %d\n", mm_num_free_pages);
 }