* pud_set_huge - setup kernel PUD mapping
*
* MTRRs can override PAT memory types with 4KiB granularity. Therefore, this
- * function sets up a huge page only if any of the following conditions are met:
- *
- * - MTRRs are disabled, or
- *
- * - MTRRs are enabled and the range is completely covered by a single MTRR, or
- *
- * - MTRRs are enabled and the corresponding MTRR memory type is WB, which
- * has no effect on the requested PAT memory type.
+ * function sets up a huge page only if the complete range has the same MTRR
+ * caching mode.
*
* Callers should try to decrease page size (1GB -> 2MB -> 4K) if the bigger
* page mapping attempt fails.
*/
int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
{
- u8 mtrr, uniform;
+ u8 uniform;
- mtrr = mtrr_type_lookup(addr, addr + PUD_SIZE, &uniform);
- if ((mtrr != MTRR_TYPE_INVALID) && (!uniform) &&
- (mtrr != MTRR_TYPE_WRBACK))
+ mtrr_type_lookup(addr, addr + PUD_SIZE, &uniform);
+ if (!uniform)
return 0;
/* Bail out if we are we on a populated non-leaf entry: */
*/
int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
{
- u8 mtrr, uniform;
+ u8 uniform;
- mtrr = mtrr_type_lookup(addr, addr + PMD_SIZE, &uniform);
- if ((mtrr != MTRR_TYPE_INVALID) && (!uniform) &&
- (mtrr != MTRR_TYPE_WRBACK)) {
+ mtrr_type_lookup(addr, addr + PMD_SIZE, &uniform);
+ if (!uniform) {
pr_warn_once("%s: Cannot satisfy [mem %#010llx-%#010llx] with a huge-page mapping due to MTRR override.\n",
__func__, addr, addr + PMD_SIZE);
return 0;