[RFC PATCH v2 46/48] lmb: mark the EFI runtime memory regions as reserved

[Sughosh Ganu]

Mark the EFI runtime memory region as reserved memory during board
init so that it does not get allocated by the LMB module on subsequent
memory requests.

Signed-off-by: Sughosh Ganu <sughosh.g...@linaro.org>
---
Changes since V1: New patch

 lib/lmb.c | 41 ++++++++++++++++++++---------------------
 1 file changed, 20 insertions(+), 21 deletions(-)

diff --git a/lib/lmb.c b/lib/lmb.c
index 387ec2ac65..6018f1de31 100644
--- a/lib/lmb.c
+++ b/lib/lmb.c
@@ -19,6 +19,7 @@
 #include <asm/global_data.h>
 #include <asm/sections.h>
 #include <linux/kernel.h>
+#include <linux/sizes.h>
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -212,33 +213,31 @@ void arch_lmb_reserve_generic(ulong sp, ulong end, ulong 
align)
 /**
  * efi_lmb_reserve() - add reservations for EFI memory
  *
- * Add reservations for all EFI memory areas that are not
- * EFI_CONVENTIONAL_MEMORY.
+ * Add reservations for EFI runtime services memory
  *
- * Return:     0 on success, 1 on failure
+ * Return: None
  */
-static __maybe_unused int efi_lmb_reserve(void)
+static __maybe_unused void efi_lmb_reserve(void)
 {
-       struct efi_mem_desc *memmap = NULL, *map;
-       efi_uintn_t i, map_size = 0;
-       efi_status_t ret;
+       phys_addr_t runtime_start, runtime_end;
+       unsigned long runtime_mask = EFI_PAGE_MASK;
 
-       ret = efi_get_memory_map_alloc(&map_size, &memmap);
-       if (ret != EFI_SUCCESS)
-               return 1;
+#if defined(__aarch64__)
+       /*
+        * Runtime Services must be 64KiB aligned according to the
+        * "AArch64 Platforms" section in the UEFI spec (2.7+).
+        */
 
-       for (i = 0, map = memmap; i < map_size / sizeof(*map); ++map, ++i) {
-               if (map->type != EFI_CONVENTIONAL_MEMORY) {
-                       lmb_reserve_flags(map_to_sysmem((void *)(uintptr_t)
-                                                       map->physical_start),
-                                         map->num_pages * EFI_PAGE_SIZE,
-                                         map->type == EFI_RESERVED_MEMORY_TYPE
-                                             ? LMB_NOMAP : LMB_NONE);
-               }
-       }
-       efi_free_pool(memmap);
+       runtime_mask = SZ_64K - 1;
+#endif
 
-       return 0;
+       /* Reserve the EFI runtime services memory */
+       runtime_start = (uintptr_t)__efi_runtime_start & ~runtime_mask;
+       runtime_end = (uintptr_t)__efi_runtime_stop;
+       runtime_end = (runtime_end + runtime_mask) & ~runtime_mask;
+
+       lmb_reserve_flags(runtime_start, runtime_end - runtime_start,
+                         LMB_NOOVERWRITE | LMB_NONOTIFY);
 }
 
 static void lmb_reserve_common(void *fdt_blob)
-- 
2.34.1