x86, pat: ioremap to follow same PAT restrictions as other PAT users

ioremap has this hard-coded check for new type and requested type. That
check differs from other PAT users like /dev/mem mmap, remap_pfn_range
in only one condition where requested type is UC_MINUS and new type
is WC. Under that condition, ioremap fails. But other PAT interfaces succeed
with a WC mapping.

Change to make ioremap be in sync with other PAT APIs and use the same
macro as others. Also changes the error print to KERN_ERR instead of
pr_debug.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>

1 files changed, 3 insertions, 14 deletions

diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 8a450930834f..aeaea8c5b2f4 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -228,24 +228,13 @@ static void __iomem *__ioremap_caller(resource_size_t phys_addr,
         retval = reserve_memtype(phys_addr, (u64)phys_addr + size,
                                                 prot_val, &new_prot_val);
         if (retval) {
-                pr_debug("Warning: reserve_memtype returned %d\n", retval);
+                printk(KERN_ERR "ioremap reserve_memtype failed %d\n", retval);
                 return NULL;
         }
 
         if (prot_val != new_prot_val) {
-                /*
-                 * Do not fallback to certain memory types with certain
-                 * requested type:
-                 * - request is uc-, return cannot be write-back
-                 * - request is uc-, return cannot be write-combine
-                 * - request is write-combine, return cannot be write-back
-                 */
-                if ((prot_val == _PAGE_CACHE_UC_MINUS &&
-                     (new_prot_val == _PAGE_CACHE_WB ||
-                      new_prot_val == _PAGE_CACHE_WC)) ||
-                    (prot_val == _PAGE_CACHE_WC &&
-                     new_prot_val == _PAGE_CACHE_WB)) {
-                        pr_debug(
+                if (!is_new_memtype_allowed(prot_val, new_prot_val)) {
+                        printk(KERN_ERR
                 "ioremap error for 0x%llx-0x%llx, requested 0x%lx, got 0x%lx\n",
                                 (unsigned long long)phys_addr,
                                 (unsigned long long)(phys_addr + size),