[igt-dev] [PATCH i-g-t] lib/intel_batchbuffer: Fix relocs across the 4GB address boundary

[Zbigniew Kempczyński]

On Mon, Nov 09, 2020 at 02:06:31PM +0200, Imre Deak wrote:
> If the delta of a relocation target wrt. the object base address crosses
> the 4GB address boundary the upper 32bit of the target address will be
> incorrect, fix this.

Give me a day, I'm going to add accompanying test. I need to do this
twice - one with current API and second for allocator series where 
API changed a bit in alignment management.

--
Zbigniew

> 
> Cc: Zbigniew Kempczyński <zbigniew.kempczynski at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Signed-off-by: Imre Deak <imre.deak at intel.com>
> ---
>  lib/intel_batchbuffer.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/intel_batchbuffer.c b/lib/intel_batchbuffer.c
> index fc73495c0..7b4cfb0dd 100644
> --- a/lib/intel_batchbuffer.c
> +++ b/lib/intel_batchbuffer.c
> @@ -1850,7 +1850,7 @@ static uint64_t __intel_bb_emit_reloc(struct intel_bb *ibb,
>  
>  	intel_bb_out(ibb, delta + address);
>  	if (ibb->gen >= 8)
> -		intel_bb_out(ibb, address >> 32);
> +		intel_bb_out(ibb, (delta + address) >> 32);
>  
>  	return address;
>  }
> -- 
> 2.25.1
>