x86/efi: Cleanup efi_enter_virtual_mode() function

Add two small functions:
efi_merge_regions() and efi_map_regions(), efi_enter_virtual_mode()
calls them instead of embedding two long for loop.

Signed-off-by: Dave Young <dyoung@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 15e3b5ea31b50b12784fa313b9261fe75d5b6e84..4694632ef581ea667a09b61496f93417d4b7a930 100644 (file)
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -773,44 +773,12 @@ void __init old_map_region(efi_memory_desc_t *md)
                       (unsigned long long)md->phys_addr);
 }
 
-/*
- * This function will switch the EFI runtime services to virtual mode.
- * Essentially, we look through the EFI memmap and map every region that
- * has the runtime attribute bit set in its memory descriptor into the
- * ->trampoline_pgd page table using a top-down VA allocation scheme.
- *
- * The old method which used to update that memory descriptor with the
- * virtual address obtained from ioremap() is still supported when the
- * kernel is booted with efi=old_map on its command line. Same old
- * method enabled the runtime services to be called without having to
- * thunk back into physical mode for every invocation.
- *
- * The new method does a pagetable switch in a preemption-safe manner
- * so that we're in a different address space when calling a runtime
- * function. For function arguments passing we do copy the PGDs of the
- * kernel page table into ->trampoline_pgd prior to each call.
- */
-void __init efi_enter_virtual_mode(void)
+/* Merge contiguous regions of the same type and attribute */
+static void __init efi_merge_regions(void)
 {
+       void *p;
        efi_memory_desc_t *md, *prev_md = NULL;
-       void *p, *new_memmap = NULL;
-       unsigned long size;
-       efi_status_t status;
-       u64 end, systab;
-       int count = 0;
-
-       efi.systab = NULL;
 
-       /*
-        * We don't do virtual mode, since we don't do runtime services, on
-        * non-native EFI
-        */
-       if (!efi_is_native()) {
-               efi_unmap_memmap();
-               return;
-       }
-
-       /* Merge contiguous regions of the same type and attribute */
        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
                u64 prev_size;
                md = p;
@@ -835,8 +803,31 @@ void __init efi_enter_virtual_mode(void)
                        continue;
                }
                prev_md = md;
+       }
+}
+
+static void __init get_systab_virt_addr(efi_memory_desc_t *md)
+{
+       unsigned long size;
+       u64 end, systab;
 
+       size = md->num_pages << EFI_PAGE_SHIFT;
+       end = md->phys_addr + size;
+       systab = (u64)(unsigned long)efi_phys.systab;
+       if (md->phys_addr <= systab && systab < end) {
+               systab += md->virt_addr - md->phys_addr;
+               efi.systab = (efi_system_table_t *)(unsigned long)systab;
        }
+}
+
+/*
+ * Map efi memory ranges for runtime serivce and update new_memmap with virtual
+ * addresses.
+ */
+static void * __init efi_map_regions(int *count)
+{
+       efi_memory_desc_t *md;
+       void *p, *tmp, *new_memmap = NULL;
 
        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
                md = p;
@@ -849,26 +840,64 @@ void __init efi_enter_virtual_mode(void)
                }
 
                efi_map_region(md);
+               get_systab_virt_addr(md);
+
+               tmp = krealloc(new_memmap, (*count + 1) * memmap.desc_size,
+                              GFP_KERNEL);
+               if (!tmp)
+                       goto out_krealloc;
+               new_memmap = tmp;
+               memcpy(new_memmap + (*count * memmap.desc_size), md,
+                      memmap.desc_size);
+               (*count)++;
+       }
 
-               size = md->num_pages << EFI_PAGE_SHIFT;
-               end = md->phys_addr + size;
+       return new_memmap;
+out_krealloc:
+       kfree(new_memmap);
+       return NULL;
+}
+
+/*
+ * This function will switch the EFI runtime services to virtual mode.
+ * Essentially, we look through the EFI memmap and map every region that
+ * has the runtime attribute bit set in its memory descriptor into the
+ * ->trampoline_pgd page table using a top-down VA allocation scheme.
+ *
+ * The old method which used to update that memory descriptor with the
+ * virtual address obtained from ioremap() is still supported when the
+ * kernel is booted with efi=old_map on its command line. Same old
+ * method enabled the runtime services to be called without having to
+ * thunk back into physical mode for every invocation.
+ *
+ * The new method does a pagetable switch in a preemption-safe manner
+ * so that we're in a different address space when calling a runtime
+ * function. For function arguments passing we do copy the PGDs of the
+ * kernel page table into ->trampoline_pgd prior to each call.
+ */
+void __init efi_enter_virtual_mode(void)
+{
+       efi_status_t status;
+       void *new_memmap = NULL;
+       int count = 0;
 
-               systab = (u64) (unsigned long) efi_phys.systab;
-               if (md->phys_addr <= systab && systab < end) {
-                       systab += md->virt_addr - md->phys_addr;
+       efi.systab = NULL;
 
-                       efi.systab = (efi_system_table_t *) (unsigned long) systab;
-               }
+       /*
+        * We don't do virtual mode, since we don't do runtime services, on
+        * non-native EFI
+        */
+       if (!efi_is_native()) {
+               efi_unmap_memmap();
+               return;
+       }
 
-               new_memmap = krealloc(new_memmap,
-                                     (count + 1) * memmap.desc_size,
-                                     GFP_KERNEL);
-               if (!new_memmap)
-                       goto err_out;
+       efi_merge_regions();
 
-               memcpy(new_memmap + (count * memmap.desc_size), md,
-                      memmap.desc_size);
-               count++;
+       new_memmap = efi_map_regions(&count);
+       if (!new_memmap) {
+               pr_err("Error reallocating memory, EFI runtime non-functional!\n");
+               return;
        }
 
        BUG_ON(!efi.systab);
@@ -922,9 +951,6 @@ void __init efi_enter_virtual_mode(void)
                         0, NULL);
 
        return;
-
- err_out:
-       pr_err("Error reallocating memory, EFI runtime non-functional!\n");
 }
 
 /*