text: /* SPDX-License-Identifier: GPL-2.0 */
  #ifndef _ASM_X86_AGP_H
  #define _ASM_X86_AGP_H
  
  #include <linux/pgtable.h>
  #include <asm/cacheflush.h>
  
  /*
   * Functions to keep the agpgart mappings coherent with the MMU. The
   * GART gives the CPU a physical alias of pages in memory. The alias
   * region is mapped uncacheable. Make sure there are no conflicting
   * mappings with different cacheability attributes for the same
   * page. This avoids data corruption on some CPUs.
   */
  
  #define map_page_into_agp(page) set_pages_uc(page, 1)
  #define unmap_page_from_agp(page) set_pages_wb(page, 1)
  
  /*
   * Could use CLFLUSH here if the cpu supports it. But then it would
   * need to be called for each cacheline of the whole page so it may
   * not be worth it. Would need a page for it.
   */
  #define flush_agp_cache() wbinvd()
  
  /* GATT allocation. Returns/accepts GATT kernel virtual address. */
  #define alloc_gatt_pages(order)		\
  	((char *)__get_free_pages(GFP_KERNEL, (order)))
  #define free_gatt_pages(table, order)	\
  	free_pages((unsigned long)(table), (order))
  
  #endif /* _ASM_X86_AGP_H */
  