#include <linux/ioport.h>
  #include <asm/e820.h>

  static void resource_clip(struct resource *res, resource_size_t start,
  			  resource_size_t end)
  {
  	resource_size_t low = 0, high = 0;
  
  	if (res->end < start || res->start > end)
  		return;		/* no conflict */
  
  	if (res->start < start)
  		low = start - res->start;
  
  	if (res->end > end)
  		high = res->end - end;
  
  	/* Keep the area above or below the conflict, whichever is larger */
  	if (low > high)
  		res->end = start - 1;
  	else
  		res->start = end + 1;
  }
  
  static void remove_e820_regions(struct resource *avail)
  {
  	int i;
  	struct e820entry *entry;
  
  	for (i = 0; i < e820.nr_map; i++) {
  		entry = &e820.map[i];
  
  		resource_clip(avail, entry->addr,
  			      entry->addr + entry->size - 1);
  	}
  }

  void arch_remove_reservations(struct resource *avail)
  {

  	/* Trim out BIOS areas (low 1MB and high 2MB) and E820 regions */

  	if (avail->flags & IORESOURCE_MEM) {
  		if (avail->start < BIOS_END)
  			avail->start = BIOS_END;

  		resource_clip(avail, BIOS_ROM_BASE, BIOS_ROM_END);

  
  		remove_e820_regions(avail);

  	}
  }