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Diffstat (limited to 'lib/efi_loader/efi_memory.c')
-rw-r--r--lib/efi_loader/efi_memory.c42
1 files changed, 39 insertions, 3 deletions
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index be642f1..de28db6 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -34,6 +34,19 @@ void *efi_bounce_buffer;
#endif
/*
+ * U-Boot services each EFI AllocatePool request as a separate
+ * (multiple) page allocation. We have to track the number of pages
+ * to be able to free the correct amount later.
+ * EFI requires 8 byte alignment for pool allocations, so we can
+ * prepend each allocation with an 64 bit header tracking the
+ * allocation size, and hand out the remainder to the caller.
+ */
+struct efi_pool_allocation {
+ u64 num_pages;
+ char data[];
+};
+
+/*
* Sorts the memory list from highest address to lowest address
*
* When allocating memory we should always start from the highest
@@ -332,11 +345,34 @@ efi_status_t efi_allocate_pool(int pool_type, unsigned long size,
{
efi_status_t r;
efi_physical_addr_t t;
- u64 num_pages = (size + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
+ u64 num_pages = (size + sizeof(u64) + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
+
+ if (size == 0) {
+ *buffer = NULL;
+ return EFI_SUCCESS;
+ }
r = efi_allocate_pages(0, pool_type, num_pages, &t);
- if (r == EFI_SUCCESS)
- *buffer = (void *)(uintptr_t)t;
+
+ if (r == EFI_SUCCESS) {
+ struct efi_pool_allocation *alloc = (void *)(uintptr_t)t;
+ alloc->num_pages = num_pages;
+ *buffer = alloc->data;
+ }
+
+ return r;
+}
+
+efi_status_t efi_free_pool(void *buffer)
+{
+ efi_status_t r;
+ struct efi_pool_allocation *alloc;
+
+ alloc = container_of(buffer, struct efi_pool_allocation, data);
+ /* Sanity check, was the supplied address returned by allocate_pool */
+ assert(((uintptr_t)alloc & EFI_PAGE_MASK) == 0);
+
+ r = efi_free_pages((uintptr_t)alloc, alloc->num_pages);
return r;
}