x86: add e820_remove_range

... so could add real hole in e820

agp check is using request_mem_region, and could fail if e820 is reserved...

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 7b613d2..e285ea3 100644 (file)
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -429,6 +429,41 @@ u64 __init e820_update_range(u64 start, u64 size, unsigned old_type,
        return real_updated_size;
 }
 
+/* make e820 not cover the range */
+u64 __init e820_remove_range(u64 start, u64 size, unsigned old_type,
+                            int checktype)
+{
+       int i;
+       u64 real_removed_size = 0;
+
+       for (i = 0; i < e820.nr_map; i++) {
+               struct e820entry *ei = &e820.map[i];
+               u64 final_start, final_end;
+
+               if (checktype && ei->type != old_type)
+                       continue;
+               /* totally covered? */
+               if (ei->addr >= start &&
+                   (ei->addr + ei->size) <= (start + size)) {
+                       real_removed_size += ei->size;
+                       memset(ei, 0, sizeof(struct e820entry));
+                       continue;
+               }
+               /* partially covered */
+               final_start = max(start, ei->addr);
+               final_end = min(start + size, ei->addr + ei->size);
+               if (final_start >= final_end)
+                       continue;
+               real_removed_size += final_end - final_start;
+
+               ei->size -= final_end - final_start;
+               if (ei->addr < final_start)
+                       continue;
+               ei->addr = final_end;
+       }
+       return real_removed_size;
+}
+
 void __init update_e820(void)
 {
        int nr_map;

diff --git a/include/asm-x86/e820.h b/include/asm-x86/e820.h
index 0e92b6a..7c32df0 100644 (file)
--- a/include/asm-x86/e820.h
+++ b/include/asm-x86/e820.h
@@ -67,6 +67,8 @@ sanitize_e820_map(struct e820entry *biosmap, int max_nr_map, int *pnr_map);
 extern int copy_e820_map(struct e820entry *biosmap, int nr_map);
 extern u64 e820_update_range(u64 start, u64 size, unsigned old_type,
                               unsigned new_type);
+extern u64 e820_remove_range(u64 start, u64 size, unsigned old_type,
+                            int checktype);
 extern void update_e820(void);
 extern void e820_setup_gap(void);
 struct setup_data;