RE: [PATCH 2/2] remoteproc: imx_dsp_rproc: use common rproc_elf_load_segments

[Peng Fan]

> Subject: Re: [PATCH 2/2] remoteproc: imx_dsp_rproc: use common
> rproc_elf_load_segments
> 
> On Thu, Mar 24, 2022 at 1:34 AM Peng Fan (OSS) <peng.fan@xxxxxxxxxxx>
> wrote:
> >
> > From: Peng Fan <peng.fan@xxxxxxx>
> >
> > remoteproc elf loader supports the specific case that segments have
> > PT_LOAD and memsz/filesz set to zero, so no duplicate code.
> >
> > Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
> 
> I think this change OK, but we have a case with the DSP were reads/writes
> should be done in multiples of 32/64.
> 
> We need a way to provide our own "memcpy" function to be used by
> rproc_elf_load_segments.

I think when generating elf file, the sections needs to be 32/64bits aligned.

Regards,
Peng.

> 
> > ---
> >  drivers/remoteproc/imx_dsp_rproc.c | 95
> > +-----------------------------
> >  1 file changed, 1 insertion(+), 94 deletions(-)
> >
> > diff --git a/drivers/remoteproc/imx_dsp_rproc.c
> > b/drivers/remoteproc/imx_dsp_rproc.c
> > index 2abee78df96e..eee3c44c2146 100644
> > --- a/drivers/remoteproc/imx_dsp_rproc.c
> > +++ b/drivers/remoteproc/imx_dsp_rproc.c
> > @@ -649,99 +649,6 @@ static int imx_dsp_rproc_add_carveout(struct
> imx_dsp_rproc *priv)
> >         return 0;
> >  }
> >
> > -/**
> > - * imx_dsp_rproc_elf_load_segments() - load firmware segments to
> > memory
> > - * @rproc: remote processor which will be booted using these fw
> > segments
> > - * @fw: the ELF firmware image
> > - *
> > - * This function specially checks if memsz is zero or not, otherwise
> > it
> > - * is mostly same as rproc_elf_load_segments().
> > - */
> > -static int imx_dsp_rproc_elf_load_segments(struct rproc *rproc,
> > -                                          const struct firmware
> *fw)
> > -{
> > -       struct device *dev = &rproc->dev;
> > -       u8 class = fw_elf_get_class(fw);
> > -       u32 elf_phdr_get_size = elf_size_of_phdr(class);
> > -       const u8 *elf_data = fw->data;
> > -       const void *ehdr, *phdr;
> > -       int i, ret = 0;
> > -       u16 phnum;
> > -
> > -       ehdr = elf_data;
> > -       phnum = elf_hdr_get_e_phnum(class, ehdr);
> > -       phdr = elf_data + elf_hdr_get_e_phoff(class, ehdr);
> > -
> > -       /* go through the available ELF segments */
> > -       for (i = 0; i < phnum; i++, phdr += elf_phdr_get_size) {
> > -               u64 da = elf_phdr_get_p_paddr(class, phdr);
> > -               u64 memsz = elf_phdr_get_p_memsz(class, phdr);
> > -               u64 filesz = elf_phdr_get_p_filesz(class, phdr);
> > -               u64 offset = elf_phdr_get_p_offset(class, phdr);
> > -               u32 type = elf_phdr_get_p_type(class, phdr);
> > -               void *ptr;
> > -
> > -               /*
> > -                *  There is a case that with PT_LOAD type, the
> > -                *  filesz = memsz = 0. If memsz = 0, rproc_da_to_va
> > -                *  should return NULL ptr, then error is returned.
> > -                *  So this case should be skipped from the loop.
> > -                *  Add !memsz checking here.
> > -                */
> > -               if (type != PT_LOAD || !memsz)
> > -                       continue;
> > -
> > -               dev_dbg(dev, "phdr: type %d da 0x%llx memsz 0x%llx
> filesz 0x%llx\n",
> > -                       type, da, memsz, filesz);
> > -
> > -               if (filesz > memsz) {
> > -                       dev_err(dev, "bad phdr filesz 0x%llx memsz
> 0x%llx\n",
> > -                               filesz, memsz);
> > -                       ret = -EINVAL;
> > -                       break;
> > -               }
> > -
> > -               if (offset + filesz > fw->size) {
> > -                       dev_err(dev, "truncated fw: need 0x%llx avail
> 0x%zx\n",
> > -                               offset + filesz, fw->size);
> > -                       ret = -EINVAL;
> > -                       break;
> > -               }
> > -
> > -               if (!rproc_u64_fit_in_size_t(memsz)) {
> > -                       dev_err(dev, "size (%llx) does not fit in size_t
> type\n",
> > -                               memsz);
> > -                       ret = -EOVERFLOW;
> > -                       break;
> > -               }
> > -
> > -               /* grab the kernel address for this device address */
> > -               ptr = rproc_da_to_va(rproc, da, memsz, NULL);
> > -               if (!ptr) {
> > -                       dev_err(dev, "bad phdr da 0x%llx mem
> 0x%llx\n", da,
> > -                               memsz);
> > -                       ret = -EINVAL;
> > -                       break;
> > -               }
> > -
> > -               /* put the segment where the remote processor expects
> it */
> > -               if (filesz)
> > -                       memcpy(ptr, elf_data + offset, filesz);
> > -
> > -               /*
> > -                * Zero out remaining memory for this segment.
> > -                *
> > -                * This isn't strictly required since dma_alloc_coherent
> already
> > -                * did this for us. albeit harmless, we may consider
> removing
> > -                * this.
> > -                */
> > -               if (memsz > filesz)
> > -                       memset(ptr + filesz, 0, memsz - filesz);
> > -       }
> > -
> > -       return ret;
> > -}
> > -
> >  /* Prepare function for rproc_ops */
> >  static int imx_dsp_rproc_prepare(struct rproc *rproc)  { @@ -808,7
> > +715,7 @@ static const struct rproc_ops imx_dsp_rproc_ops = {
> >         .start          = imx_dsp_rproc_start,
> >         .stop           = imx_dsp_rproc_stop,
> >         .kick           = imx_dsp_rproc_kick,
> > -       .load           = imx_dsp_rproc_elf_load_segments,
> > +       .load           = rproc_elf_load_segments,
> >         .parse_fw       = rproc_elf_load_rsc_table,
> >         .sanity_check   = rproc_elf_sanity_check,
> >         .get_boot_addr  = rproc_elf_get_boot_addr,
> > --
> > 2.25.1
> >