[PATCH 06/16] Enforce minimum alignment of 1 page on allocations. The efi_high_alloc() and efi_low_alloc() functions use the EFI_ALLOCATE_ADDRESS option to the EFI function allocate_pages(), which requires a minimum of page alignment, and rejects all other requests.

Roy Franz
2013-08-09T23:26:07Z

The existing code could fail to allocate depending
on allocation size, as although repeated allocation
attempts were made, none were guaranteed to be page
aligned.

Signed-off-by: Roy Franz <roy.franz@linaro.org>
---
drivers/firmware/efi/efi-stub-helper.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/drivers/firmware/efi/efi-stub-helper.c b/drivers/firmware/efi/efi-stub-helper.c
index 1d0a079..647b3ba 100644
--- a/drivers/firmware/efi/efi-stub-helper.c
+++ b/drivers/firmware/efi/efi-stub-helper.c
@@ -105,6 +105,13 @@ static efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
if (status != EFI_SUCCESS)
goto fail;

+ /* Enforce minimum alignment that EFI requires when requesting
+ * a specific address. We are doing page-based allocations,
+ * so we must be aligned to a page.
+ */
+ if (align < EFI_PAGE_SIZE)
+ align = EFI_PAGE_SIZE;
+
nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
again:
for (i = 0; i < map_size / desc_size; i++) {
@@ -184,6 +191,13 @@ static efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
if (status != EFI_SUCCESS)
goto fail;

+ /* Enforce minimum alignment that EFI requires when requesting
+ * a specific address. We are doing page-based allocations,
+ * so we must be aligned to a page.
+ */
+ if (align < EFI_PAGE_SIZE)
+ align = EFI_PAGE_SIZE;
+
nr_pages = round_up(size, EFI_PAGE_SIZE) / EFI_PAGE_SIZE;
for (i = 0; i < map_size / desc_size; i++) {
efi_memory_desc_t *desc;
--
1.7.10.4