[U-Boot] [PATCH 1/1] efi_loader: allow adding mapped memory at 0x00000000

[Heinrich Schuchardt]

As efi_add_memory_map() signals an error by returning NULL and correct
function by returning the requested address we cannot discern an error from
correct functioning for address 0x00000000. This leads to unexpected
warnings on the Raspberry 3.

Use EFI_SUCCESS to signal success and return an error code otherwise.

Reported-by: Bryan O'Donoghue <pure.logic at nexus-software.ie>
Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
---
 cmd/bootefi.c               |  4 ++--
 include/efi_loader.h        |  4 ++--
 lib/efi_loader/efi_memory.c | 28 ++++++++++++++++++----------
 3 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index c19256e00d..04d3e3e4a7 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -169,8 +169,8 @@ static void efi_carve_out_dt_rsv(void *fdt)

 		pages = efi_size_in_pages(size + (addr & EFI_PAGE_MASK));
 		addr &= ~EFI_PAGE_MASK;
-		if (!efi_add_memory_map(addr, pages, EFI_RESERVED_MEMORY_TYPE,
-					false))
+		if (efi_add_memory_map(addr, pages, EFI_RESERVED_MEMORY_TYPE,
+				       false) != EFI_SUCCESS)
 			printf("FDT memrsv map %d: Failed to add to map\n", i);
 	}
 }
diff --git a/include/efi_loader.h b/include/efi_loader.h
index db4763fc9b..6cc6a3835c 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -476,8 +476,8 @@ efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
 				efi_uintn_t *descriptor_size,
 				uint32_t *descriptor_version);
 /* Adds a range into the EFI memory map */
-uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
-			    bool overlap_only_ram);
+efi_status_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
+				bool overlap_only_ram);
 /* Called by board init to initialize the EFI drivers */
 efi_status_t efi_driver_init(void);
 /* Called by board init to initialize the EFI memory map */
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index 27379381e8..da253fa285 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -223,8 +223,17 @@ static s64 efi_mem_carve_out(struct efi_mem_list *map,
 	return EFI_CARVE_LOOP_AGAIN;
 }

-uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
-			    bool overlap_only_ram)
+/**
+ * efi_add_memory_map() - add memory area to the memory map
+ *
+ * @start:		start address, must be a multiple of EFI_PAGE_SIZE
+ * @pages:		number of pages to add
+ * @memory_type:	type of memory added
+ * @overlap_only_ram:	the memory area must overlap existing
+ * Return:		status code
+ */
+efi_status_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
+				bool overlap_only_ram)
 {
 	struct list_head *lhandle;
 	struct efi_mem_list *newlist;
@@ -239,7 +248,7 @@ uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
 		return EFI_INVALID_PARAMETER;

 	if (!pages)
-		return start;
+		return EFI_SUCCESS;

 	++efi_memory_map_key;
 	newlist = calloc(1, sizeof(*newlist));
@@ -277,7 +286,7 @@ uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
 				 * The user requested to only have RAM overlaps,
 				 * but we hit a non-RAM region. Error out.
 				 */
-				return 0;
+				return EFI_NO_MAPPING;
 			case EFI_CARVE_NO_OVERLAP:
 				/* Just ignore this list entry */
 				break;
@@ -307,7 +316,7 @@ uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
 		 * The payload wanted to have RAM overlaps, but we overlapped
 		 * with an unallocated region. Error out.
 		 */
-		return 0;
+		return EFI_NO_MAPPING;
 	}

 	/* Add our new map */
@@ -326,7 +335,7 @@ uint64_t efi_add_memory_map(uint64_t start, uint64_t pages, int memory_type,
 		}
 	}

-	return start;
+	return EFI_SUCCESS;
 }

 /**
@@ -455,7 +464,7 @@ efi_status_t efi_allocate_pages(int type, int memory_type,
 	}

 	/* Reserve that map in our memory maps */
-	if (efi_add_memory_map(addr, pages, memory_type, true) != addr)
+	if (efi_add_memory_map(addr, pages, memory_type, true) != EFI_SUCCESS)
 		/* Map would overlap, bail out */
 		return  EFI_OUT_OF_RESOURCES;

@@ -487,7 +496,6 @@ void *efi_alloc(uint64_t len, int memory_type)
  */
 efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
 {
-	uint64_t r = 0;
 	efi_status_t ret;

 	ret = efi_check_allocated(memory, true);
@@ -501,10 +509,10 @@ efi_status_t efi_free_pages(uint64_t memory, efi_uintn_t pages)
 		return EFI_INVALID_PARAMETER;
 	}

-	r = efi_add_memory_map(memory, pages, EFI_CONVENTIONAL_MEMORY, false);
+	ret = efi_add_memory_map(memory, pages, EFI_CONVENTIONAL_MEMORY, false);
 	/* Merging of adjacent free regions is missing */

-	if (r == memory)
+	if (ret == EFI_SUCCESS)
 		return EFI_SUCCESS;

 	return EFI_NOT_FOUND;
--
2.20.1