Re: [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.

Grant Likely
2013-08-30T13:08:11Z

On Fri, 9 Aug 2013 16:26:07 -0700, Roy Franz <roy.franz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:
> 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.

Commit message. Otherwise looks reasonable.

Reviewed-by: Grant Likely <grant.likely-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>

> Signed-off-by: Roy Franz <roy.franz-QSEj5FYQhm4dnm+yROfE0A@public.gmane.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
>
>
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