efi_loader: Move efi_allocate_pool implementation to efi_memory.c

We currently handle efi_allocate_pool() in our boot time service
file. In the following patch, pool allocation will receive additional
internal semantics that we should preserve inside efi_memory.c instead.

As foundation for those changes, split the function into an externally
facing efi_allocate_pool_ext() for use by payloads and an internal helper
efi_allocate_pool() in efi_memory.c that handles the actual allocation.

While at it, change the magic 0xfff / 12 constants to the more obvious
EFI_PAGE_MASK/SHIFT defines.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Reviewed-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

include/efi_loader.h

@@ -119,6 +119,9 @@ efi_status_t efi_allocate_pages(int type, int memory_type, unsigned long pages,
 				uint64_t *memory);
 /* EFI memory free function. Not implemented today */
 efi_status_t efi_free_pages(uint64_t memory, unsigned long pages);
+/* EFI memory allocator for small allocations */
+efi_status_t efi_allocate_pool(int pool_type, unsigned long size,
+			       void **buffer);
 /* Returns the EFI memory map */
 efi_status_t efi_get_memory_map(unsigned long *memory_map_size,
 				struct efi_mem_desc *memory_map,

lib/efi_loader/efi_boottime.c

@@ -130,15 +130,14 @@ efi_status_t EFIAPI efi_get_memory_map_ext(unsigned long *memory_map_size,
 	return EFI_EXIT(r);
 }
 
-static efi_status_t EFIAPI efi_allocate_pool(int pool_type, unsigned long size,
-					     void **buffer)
+static efi_status_t EFIAPI efi_allocate_pool_ext(int pool_type,
+						 unsigned long size,
+						 void **buffer)
 {
 	efi_status_t r;
-	efi_physical_addr_t t;
 
 	EFI_ENTRY("%d, %ld, %p", pool_type, size, buffer);
-	r = efi_allocate_pages(0, pool_type, (size + 0xfff) >> 12, &t);
-	*buffer = (void *)(uintptr_t)t;
+	r = efi_allocate_pool(pool_type, size, buffer);
 	return EFI_EXIT(r);
 }
 
@@ -736,7 +735,7 @@ static const struct efi_boot_services efi_boot_services = {
 	.allocate_pages = efi_allocate_pages_ext,
 	.free_pages = efi_free_pages_ext,
 	.get_memory_map = efi_get_memory_map_ext,
-	.allocate_pool = efi_allocate_pool,
+	.allocate_pool = efi_allocate_pool_ext,
 	.free_pool = efi_free_pool,
 	.create_event = efi_create_event,
 	.set_timer = efi_set_timer,

lib/efi_loader/efi_memory.c

@@ -327,6 +327,20 @@ efi_status_t efi_free_pages(uint64_t memory, unsigned long pages)
 	return EFI_SUCCESS;
 }
 
+efi_status_t efi_allocate_pool(int pool_type, unsigned long size,
+			       void **buffer)
+{
+	efi_status_t r;
+	efi_physical_addr_t t;
+	u64 num_pages = (size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
+
+	r = efi_allocate_pages(0, pool_type, num_pages, &t);
+	if (r == EFI_SUCCESS)
+		*buffer = (void *)(uintptr_t)t;
+
+	return r;
+}
+
 efi_status_t efi_get_memory_map(unsigned long *memory_map_size,
 			       struct efi_mem_desc *memory_map,
 			       unsigned long *map_key,