x86: EFI: Back efi_ioremap with init_memory_mapping instead of FIX_MAP

Impact: Fix boot failure on EFI system with large runtime memory range

Brian Maly reported that some EFI system with large runtime memory
range can not boot. Because the FIX_MAP used to map runtime memory
range is smaller than run time memory range.

This patch fixes this issue by re-implement efi_ioremap() with
init_memory_mapping().

Reported-and-tested-by: Brian Maly <bmaly@redhat.com>
Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: Brian Maly <bmaly@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
LKML-Reference: <1236135513.6204.306.camel@yhuang-dev.sh.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 9 insertions, 19 deletions

diff --git a/arch/x86/kernel/efi.c b/arch/x86/kernel/efi.c
index 1119d247fe11..eb1ef3b67dd5 100644
--- a/arch/x86/kernel/efi.c
+++ b/arch/x86/kernel/efi.c
@@ -467,7 +467,7 @@ void __init efi_enter_virtual_mode(void)
         efi_memory_desc_t *md;
         efi_status_t status;
         unsigned long size;
-        u64 end, systab, addr, npages;
+        u64 end, systab, addr, npages, end_pfn;
         void *p, *va;
 
         efi.systab = NULL;
@@ -479,7 +479,10 @@ void __init efi_enter_virtual_mode(void)
                 size = md->num_pages << EFI_PAGE_SHIFT;
                 end = md->phys_addr + size;
 
-                if (PFN_UP(end) <= max_low_pfn_mapped)
+                end_pfn = PFN_UP(end);
+                if (end_pfn <= max_low_pfn_mapped
+                    || (end_pfn > (1UL << (32 - PAGE_SHIFT))
+                        && end_pfn <= max_pfn_mapped))
                         va = __va(md->phys_addr);
                 else
                         va = efi_ioremap(md->phys_addr, size);
diff --git a/arch/x86/kernel/efi_64.c b/arch/x86/kernel/efi_64.c
index 652c5287215f..cb783b92c50c 100644
--- a/arch/x86/kernel/efi_64.c
+++ b/arch/x86/kernel/efi_64.c
@@ -99,24 +99,11 @@ void __init efi_call_phys_epilog(void)
 
 void __iomem *__init efi_ioremap(unsigned long phys_addr, unsigned long size)
 {
-        static unsigned pages_mapped __initdata;
-        unsigned i, pages;
-        unsigned long offset;
+        unsigned long last_map_pfn;
 
-        pages = PFN_UP(phys_addr + size) - PFN_DOWN(phys_addr);
-        offset = phys_addr & ~PAGE_MASK;
-        phys_addr &= PAGE_MASK;
-
-        if (pages_mapped + pages > MAX_EFI_IO_PAGES)
+        last_map_pfn = init_memory_mapping(phys_addr, phys_addr + size);
+        if ((last_map_pfn << PAGE_SHIFT) < phys_addr + size)
                 return NULL;
 
-        for (i = 0; i < pages; i++) {
-                __set_fixmap(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped,
-                             phys_addr, PAGE_KERNEL);
-                phys_addr += PAGE_SIZE;
-                pages_mapped++;
-        }
-
-        return (void __iomem *)__fix_to_virt(FIX_EFI_IO_MAP_FIRST_PAGE - \
-                                             (pages_mapped - pages)) + offset;
+        return (void __iomem *)__va(phys_addr);
 }