x86, mm: Fixup code testing if a pfn is direct mapped

Update code that previously assumed pfns [ 0 - max_low_pfn_mapped ) and
[ 4GB - max_pfn_mapped ) were always direct mapped, to now look up
pfn_mapped ranges instead.

-v2: change applying sequence to keep git bisecting working.
     so add dummy pfn_range_is_mapped(). - Yinghai Lu

Signed-off-by: Jacob Shin <jacob.shin@amd.com>
Link: http://lkml.kernel.org/r/1353123563-3103-12-git-send-email-yinghai@kernel.org
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
index e21fdd1..45aae6e 100644 (file)
--- a/arch/x86/include/asm/page_types.h
+++ b/arch/x86/include/asm/page_types.h
@@ -51,6 +51,14 @@ static inline phys_addr_t get_max_mapped(void)
        return (phys_addr_t)max_pfn_mapped << PAGE_SHIFT;
 }
 
+static inline bool pfn_range_is_mapped(unsigned long start_pfn,
+                                       unsigned long end_pfn)
+{
+       return end_pfn <= max_low_pfn_mapped ||
+              (end_pfn > (1UL << (32 - PAGE_SHIFT)) &&
+               end_pfn <= max_pfn_mapped);
+}
+
 extern unsigned long init_memory_mapping(unsigned long start,
                                         unsigned long end);
 

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index f7e98a2..9619ba6 100644 (file)
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -676,12 +676,10 @@ static void __cpuinit init_amd(struct cpuinfo_x86 *c)
                 * benefit in doing so.
                 */
                if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
+                       unsigned long pfn = tseg >> PAGE_SHIFT;
+
                        printk(KERN_DEBUG "tseg: %010llx\n", tseg);
-                       if ((tseg>>PMD_SHIFT) <
-                               (max_low_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) ||
-                               ((tseg>>PMD_SHIFT) <
-                               (max_pfn_mapped>>(PMD_SHIFT-PAGE_SHIFT)) &&
-                               (tseg>>PMD_SHIFT) >= (1ULL<<(32 - PMD_SHIFT))))
+                       if (pfn_range_is_mapped(pfn, pfn + 1))
                                set_memory_4k((unsigned long)__va(tseg), 1);
                }
        }

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index ad44391..36e53f0 100644 (file)
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -835,7 +835,7 @@ void __init efi_enter_virtual_mode(void)
        efi_memory_desc_t *md, *prev_md = NULL;
        efi_status_t status;
        unsigned long size;
-       u64 end, systab, end_pfn;
+       u64 end, systab, start_pfn, end_pfn;
        void *p, *va, *new_memmap = NULL;
        int count = 0;
 
@@ -888,10 +888,9 @@ void __init efi_enter_virtual_mode(void)
                size = md->num_pages << EFI_PAGE_SHIFT;
                end = md->phys_addr + size;
 
+               start_pfn = PFN_DOWN(md->phys_addr);
                end_pfn = PFN_UP(end);
-               if (end_pfn <= max_low_pfn_mapped
-                   || (end_pfn > (1UL << (32 - PAGE_SHIFT))
-                       && end_pfn <= max_pfn_mapped)) {
+               if (pfn_range_is_mapped(start_pfn, end_pfn)) {
                        va = __va(md->phys_addr);
 
                        if (!(md->attribute & EFI_MEMORY_WB))