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

[Mark Salter]

On Tue, 2014-07-29 at 20:17 +0200, Ard Biesheuvel wrote:
> 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.

That's fine if the static library stub patch goes in first. If this
patch goes in first, then let's avoid the warning since it is easy
to do.

> 
> > 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;
> >>       }
> >>
> >>
> >
> >