Re: some progress with radeon on C8000

[Helge Deller <deller@gmx.de>]

On 04.10.19 14:06, Thomas Bogendoerfer wrote:
> On Wed, Oct 02, 2019 at 04:37:41PM -0400, John David Anglin wrote:
>> On 2019-10-02 10:19 a.m., Thomas Bogendoerfer wrote:
>>> +	pa = addr & IOVP_MASK;
>>> +	mtsp(0,1);
>>> +	asm("lci 0(%%sr1, %1), %0" : "=r" (ci) : "r" (__va(pa)));
>> I believe you can remove the mtsp and just use "lci 0(%1), %0" to load the coherence index.  The space
>> registers sr4 to sr7 are always 0 in kernel.
>
> ok, good to know.
>
> while reading this I realized what the other hacks were for, which I didn't
> include in my first mail.
>
> diff --git a/drivers/gpu/drm/ttm/ttm_agp_backend.c b/drivers/gpu/drm/ttm/ttm_agp_backend.c
> index 028ab6007873..e84c7652eb1b 100644
> --- a/drivers/gpu/drm/ttm/ttm_agp_backend.c
> +++ b/drivers/gpu/drm/ttm/ttm_agp_backend.c
> @@ -66,7 +67,8 @@ static int ttm_agp_bind(struct ttm_tt *ttm, struct ttm_mem_reg *bo_mem)
>   		if (!page)
>   			page = ttm->dummy_read_page;
>
> -		mem->pages[mem->page_count++] = page;
> +		mem->pages[(ttm->num_pages - 1) - mem->page_count] = page;
> +		mem->page_count++;
>   	}
>   	agp_be->mem = mem;
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
> index d0459b392e5e..4bb301cab128 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
> @@ -571,8 +571,14 @@ static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo,
>   		 */
>   		prot = ttm_io_prot(mem->placement, PAGE_KERNEL);
>   		map->bo_kmap_type = ttm_bo_map_vmap;
> +		printk("vmap %p\n", ttm->pages[start_page]);
> +#if 0
>   		map->virtual = vmap(ttm->pages + start_page, num_pages,
>   				    0, prot);
> +#else
> +		map->virtual = kmap(ttm->pages[start_page]);
> +#endif
> +
>   	}
>   	return (!map->virtual) ? -ENOMEM : 0;
>   }
>
>
> This is needed to be able to get the virtual address with __va(pa).

Can you make a documented patch out of all that?
I'd like to include it at least into a test/hack branch, e.g.
https://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux.git/commit/?h=radeon-test&id=0ef942c21d37078ae6406b3e7075f3dbe6417a04

Helge