x86/efi: Split efi_enter_virtual_mode

... into a kexec flavor for better code readability and simplicity. The
original one was getting ugly with ifdeffery.

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

1 files changed, 98 insertions, 50 deletions

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 576bb126593a..6f0a46730826 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -879,8 +879,9 @@ static void __init get_systab_virt_addr(efi_memory_desc_t *md)
         }
 }
 
-static int __init save_runtime_map(void)
+static void __init save_runtime_map(void)
 {
+#ifdef CONFIG_KEXEC
         efi_memory_desc_t *md;
         void *tmp, *p, *q = NULL;
         int count = 0;
@@ -902,28 +903,12 @@ static int __init save_runtime_map(void)
         }
 
         efi_runtime_map_setup(q, count, memmap.desc_size);
+        return;
 
-        return 0;
 out:
         kfree(q);
-        return -ENOMEM;
-}
-
-/*
- * Map efi regions which were passed via setup_data. The virt_addr is a fixed
- * addr which was used in first kernel of a kexec boot.
- */
-static void __init efi_map_regions_fixed(void)
-{
-        void *p;
-        efi_memory_desc_t *md;
-
-        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
-                md = p;
-                efi_map_region_fixed(md); /* FIXME: add error handling */
-                get_systab_virt_addr(md);
-        }
-
+        pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
+#endif
 }
 
 static void *realloc_pages(void *old_memmap, int old_shift)
@@ -989,6 +974,72 @@ static void * __init efi_map_regions(int *count, int *pg_shift)
         return new_memmap;
 }
 
+static void __init kexec_enter_virtual_mode(void)
+{
+#ifdef CONFIG_KEXEC
+        efi_memory_desc_t *md;
+        void *p;
+
+        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;
+        }
+
+        /*
+        * Map efi regions which were passed via setup_data. The virt_addr is a
+        * fixed addr which was used in first kernel of a kexec boot.
+        */
+        for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {
+                md = p;
+                efi_map_region_fixed(md); /* FIXME: add error handling */
+                get_systab_virt_addr(md);
+        }
+
+        save_runtime_map();
+
+        BUG_ON(!efi.systab);
+
+        efi_sync_low_kernel_mappings();
+
+        /*
+         * Now that EFI is in virtual mode, update the function
+         * pointers in the runtime service table to the new virtual addresses.
+         *
+         * Call EFI services through wrapper functions.
+         */
+        efi.runtime_version = efi_systab.hdr.revision;
+        efi.get_time = virt_efi_get_time;
+        efi.set_time = virt_efi_set_time;
+        efi.get_wakeup_time = virt_efi_get_wakeup_time;
+        efi.set_wakeup_time = virt_efi_set_wakeup_time;
+        efi.get_variable = virt_efi_get_variable;
+        efi.get_next_variable = virt_efi_get_next_variable;
+        efi.set_variable = virt_efi_set_variable;
+        efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;
+        efi.reset_system = virt_efi_reset_system;
+        efi.set_virtual_address_map = NULL;
+        efi.query_variable_info = virt_efi_query_variable_info;
+        efi.update_capsule = virt_efi_update_capsule;
+        efi.query_capsule_caps = virt_efi_query_capsule_caps;
+
+        if (efi_enabled(EFI_OLD_MEMMAP) && (__supported_pte_mask & _PAGE_NX))
+                runtime_code_page_mkexec();
+
+        /* clean DUMMY object */
+        efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
+                         EFI_VARIABLE_NON_VOLATILE |
+                         EFI_VARIABLE_BOOTSERVICE_ACCESS |
+                         EFI_VARIABLE_RUNTIME_ACCESS,
+                         0, NULL);
+#endif
+}
+
 /*
  * This function will switch the EFI runtime services to virtual mode.
  * Essentially, we look through the EFI memmap and map every region that
@@ -1008,11 +1059,12 @@ static void * __init efi_map_regions(int *count, int *pg_shift)
  *
  * Specially for kexec boot, efi runtime maps in previous kernel should
  * be passed in via setup_data. In that case runtime ranges will be mapped
- * to the same virtual addresses as the first kernel.
+ * to the same virtual addresses as the first kernel, see
+ * kexec_enter_virtual_mode().
  */
-void __init efi_enter_virtual_mode(void)
+static void __init __efi_enter_virtual_mode(void)
 {
-        int err, count = 0, pg_shift = 0;
+        int count = 0, pg_shift = 0;
         void *new_memmap = NULL;
         efi_status_t status;
 
@@ -1027,43 +1079,33 @@ void __init efi_enter_virtual_mode(void)
                 return;
         }
 
-        if (efi_setup) {
-                efi_map_regions_fixed();
-        } else {
-                efi_merge_regions();
-                new_memmap = efi_map_regions(&count, &pg_shift);
-                if (!new_memmap) {
-                        pr_err("Error reallocating memory, EFI runtime non-functional!\n");
-                        return;
-                }
-
-                err = save_runtime_map();
-                if (err)
-                        pr_err("Error saving runtime map, efi runtime on kexec non-functional!!\n");
+        efi_merge_regions();
+        new_memmap = efi_map_regions(&count, &pg_shift);
+        if (!new_memmap) {
+                pr_err("Error reallocating memory, EFI runtime non-functional!\n");
+                return;
         }
 
+        save_runtime_map();
+
         BUG_ON(!efi.systab);
 
-        if (!efi_setup) {
-                if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift))
-                        return;
-        }
+        if (efi_setup_page_tables(__pa(new_memmap), 1 << pg_shift))
+                return;
 
         efi_sync_low_kernel_mappings();
         efi_dump_pagetable();
 
-        if (!efi_setup) {
-                status = phys_efi_set_virtual_address_map(
+        status = phys_efi_set_virtual_address_map(
                         memmap.desc_size * count,
                         memmap.desc_size,
                         memmap.desc_version,
                         (efi_memory_desc_t *)__pa(new_memmap));
 
-                if (status != EFI_SUCCESS) {
-                        pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
-                                 status);
-                        panic("EFI call to SetVirtualAddressMap() failed!");
-                }
+        if (status != EFI_SUCCESS) {
+                pr_alert("Unable to switch EFI into virtual mode (status=%lx)!\n",
+                         status);
+                panic("EFI call to SetVirtualAddressMap() failed!");
         }
 
         /*
@@ -1089,7 +1131,6 @@ void __init efi_enter_virtual_mode(void)
 
         efi_runtime_mkexec();
 
-
         /*
          * We mapped the descriptor array into the EFI pagetable above but we're
          * not unmapping it here. Here's why:
@@ -1116,8 +1157,7 @@ void __init efi_enter_virtual_mode(void)
          *
          * efi_cleanup_page_tables(__pa(new_memmap), 1 << pg_shift);
          */
-        if (!efi_setup)
-                free_pages((unsigned long)new_memmap, pg_shift);
+        free_pages((unsigned long)new_memmap, pg_shift);
 
         /* clean DUMMY object */
         efi.set_variable(efi_dummy_name, &EFI_DUMMY_GUID,
@@ -1127,6 +1167,14 @@ void __init efi_enter_virtual_mode(void)
                          0, NULL);
 }
 
+void __init efi_enter_virtual_mode(void)
+{
+        if (efi_setup)
+                kexec_enter_virtual_mode();
+        else
+                __efi_enter_virtual_mode();
+}
+
 /*
  * Convenience functions to obtain memory types and attributes
  */