[PATCH 3/3] arm64/efi: efistub: don't abort if base of DRAM is occupied

[Ard Biesheuvel]

On 29 July 2014 17:29, Mark Salter <msalter at redhat.com> wrote:
> On Tue, 2014-07-29 at 12:49 +0200, Ard Biesheuvel wrote:
>> If we cannot relocate the kernel Image to its preferred offset of base of DRAM
>> plus TEXT_OFFSET, instead relocate it to the lowest available 2 MB boundary plus
>> TEXT_OFFSET. We may lose a bit of memory at the low end, but we can still
>> proceed normally otherwise.
>>
>> Signed-off-by: Ard Biesheuvel <ard.biesheuvel at linaro.org>
>> ---
>>  arch/arm64/kernel/efi-stub.c | 16 ++++++----------
>>  1 file changed, 6 insertions(+), 10 deletions(-)
>
> Tested on Mustang (with loss of 2MB free memory).
>

Great, thanks!

>>
>> diff --git a/arch/arm64/kernel/efi-stub.c b/arch/arm64/kernel/efi-stub.c
>> index 60e98a639ac5..460c00c41e57 100644
>> --- a/arch/arm64/kernel/efi-stub.c
>> +++ b/arch/arm64/kernel/efi-stub.c
>> @@ -60,20 +60,16 @@ static efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
>>       kernel_size = _edata - _text;
>>       if (*image_addr != (dram_base + TEXT_OFFSET)) {
>>               kernel_memsize = kernel_size + (_end - _edata);
>> -             status = efi_relocate_kernel(sys_table, image_addr,
>> -                                          kernel_size, kernel_memsize,
>> -                                          dram_base + TEXT_OFFSET,
>> -                                          PAGE_SIZE);
>
> Can we make efi_relocate_kernel static inline to get rid
> of the "defined but unused" warning?
>

I have some patches pending in the EFI tree to turn the stub into a
static library, and that already takes care of this issue.

> Otherwise:
>
> Acked-by: Mark Salter <msalter at redhat.com>
>

Cheers,
Ard.



>> +             status = efi_low_alloc(sys_table, kernel_memsize + TEXT_OFFSET,
>> +                                    SZ_2M, reserve_addr);
>>               if (status != EFI_SUCCESS) {
>>                       pr_efi_err(sys_table, "Failed to relocate kernel\n");
>>                       return status;
>>               }
>> -             if (*image_addr != (dram_base + TEXT_OFFSET)) {
>> -                     pr_efi_err(sys_table, "Failed to alloc kernel memory\n");
>> -                     efi_free(sys_table, kernel_memsize, *image_addr);
>> -                     return EFI_ERROR;
>> -             }
>> -             *image_size = kernel_memsize;
>> +             memcpy((void *)*reserve_addr + TEXT_OFFSET, (void *)*image_addr,
>> +                    kernel_size);
>> +             *image_addr = *reserve_addr + TEXT_OFFSET;
>> +             *reserve_size = kernel_memsize + TEXT_OFFSET;
>>       }
>>
>>
>
>