Re: [PATCH i-g-t v2 3/3] tests/panthor: add panthor tests

[Boris Brezillon <boris.brezillon@collabora.com>]

On Tue, 7 Oct 2025 13:40:11 -0300
Daniel Almeida <daniel.almeida@collabora.com> wrote:

> > On 7 Oct 2025, at 10:39, Daniel Almeida <daniel.almeida@collabora.com> wrote:
> > 
> > Hi Dan, thanks for the review!
> > 
> > […]
> >   
> >>   
> >>> +static void
> >>> +issue_store_multiple(u8 *command_stream, uint64_t kernel_va, uint32_t constant)
> >>> +{
> >>> +               uint64_t opcode, reg_num, mov48, store_multiple, flush;
> >>> +               uint64_t sr, src0, register_bitmap, offset;
> >>> +
> >>> +               // MOV48: Load the source register ([r68; r69]) with the kernel address
> >>> +               opcode = 0x1;
> >>> +               reg_num = 68;
> >>> +               mov48 = (opcode << 56) | (reg_num << 48) | kernel_va;
> >>> +               mov48 = htole64(mov48);
> >>> +               memcpy(&command_stream[0], &mov48, sizeof(mov48));
> >>> +
> >>> +               // MOV48: Load a known constant into r70
> >>> +               opcode = 0x1;
> >>> +               reg_num = 70;
> >>> +               mov48 = (opcode << 56) | (reg_num << 48) | constant;
> >>> +               mov48 = htole64(mov48);
> >>> +               memcpy(&command_stream[8], &mov48, sizeof(mov48));
> >>> +
> >>> +               // STORE_MULTIPLE: Store the first register to the address pointed to by [r68; r69]
> >>> +               opcode = 0x15; // STORE_MULTIPLE
> >>> +               sr = 70; // Starting from register r70
> >>> +               src0 = 68; // Address pointed to by [r68; r69]
> >>> +               register_bitmap = 1; // Store the first register
> >>> +               offset = 0; // Offset
> >>> +               store_multiple = (opcode << 56) | (sr << 48) | (src0 << 40) |
> >>> +                                                                                (register_bitmap << 16) | offset;
> >>> +               store_multiple = htole64(store_multiple);
> >>> +               memcpy(&command_stream[16], &store_multiple, sizeof(store_multiple));  
> >> 
> >> // MOV48 r68, 0 on the below?  
> > 
> > Wdym? / Why?
> > 
> > I want to clarify what you mean here because it was a bit tricky to get this to
> > work, so I am trying to be really mindful about any changes so that it
> > doesn’t break.
> >   
> 
> Oh, I now see that you probably also want this to be a comment placed before the
> opcode like the FLUSH_CACHES below.

BTW, if we start adding more tests using manually forged command
streams, it might make sense to provides some sort of helpers like
those we have in mesa[1], but let's keep that for later.

[1]https://elixir.bootlin.com/mesa/mesa-25.2.4/source/src/panfrost/genxml/cs_builder.h