Re: [PATCH] PCI: mvebu: Use for_each_of_range() iterator for parsing "ranges"

Pali Rohár
2025-02-16T16:54:19Z

On Friday 15 November 2024 13:01:04 Manivannan Sadhasivam wrote:
> On Thu, Nov 07, 2024 at 09:32:55AM -0600, Rob Herring (Arm) wrote:
> > The mvebu "ranges" is a bit unusual with its own encoding of addresses,
> > but it's still just normal "ranges" as far as parsing is concerned.
> > Convert mvebu_get_tgt_attr() to use the for_each_of_range() iterator
> > instead of open coding the parsing.
> >
> > Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
>
> LGTM!
>
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
>
> Could someone please verify it on mvebu machine?
>
> - Mani

That is mostly impossible as pci-mvebu is broken. Bjorn and Krzysztof in
past already refused to take patches which would fix the driver or
extend it for other platforms.

So I do not understand why you are rewriting something which worked,
instead of fixing something which is broken. The only point can be to
make driver even more broken...

> > ---
> > Compile tested only.
> > ---
> > drivers/pci/controller/pci-mvebu.c | 26 +++++++++-----------------
> > 1 file changed, 9 insertions(+), 17 deletions(-)
> >
> > diff --git a/drivers/pci/controller/pci-mvebu.c b/drivers/pci/controller/pci-mvebu.c
> > index 29fe09c99e7d..d4e3f1e76f84 100644
> > --- a/drivers/pci/controller/pci-mvebu.c
> > +++ b/drivers/pci/controller/pci-mvebu.c
> > @@ -1179,37 +1179,29 @@ static int mvebu_get_tgt_attr(struct device_node *np, int devfn,
> > unsigned int *tgt,
> > unsigned int *attr)
> > {
> > - const int na = 3, ns = 2;
> > - const __be32 *range;
> > - int rlen, nranges, rangesz, pna, i;
> > + struct of_range range;
> > + struct of_range_parser parser;
> >
> > *tgt = -1;
> > *attr = -1;
> >
> > - range = of_get_property(np, "ranges", &rlen);
> > - if (!range)
> > + if (of_pci_range_parser_init(&parser, np))
> > return -EINVAL;
> >
> > - pna = of_n_addr_cells(np);
> > - rangesz = pna + na + ns;
> > - nranges = rlen / sizeof(__be32) / rangesz;
> > -
> > - for (i = 0; i < nranges; i++, range += rangesz) {
> > - u32 flags = of_read_number(range, 1);
> > - u32 slot = of_read_number(range + 1, 1);
> > - u64 cpuaddr = of_read_number(range + na, pna);
> > + for_each_of_range(&parser, &range) {
> > unsigned long rtype;
> > + u32 slot = upper_32_bits(range.bus_addr);
> >
> > - if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_IO)
> > + if (DT_FLAGS_TO_TYPE(range.flags) == DT_TYPE_IO)
> > rtype = IORESOURCE_IO;
> > - else if (DT_FLAGS_TO_TYPE(flags) == DT_TYPE_MEM32)
> > + else if (DT_FLAGS_TO_TYPE(range.flags) == DT_TYPE_MEM32)
> > rtype = IORESOURCE_MEM;
> > else
> > continue;
> >
> > if (slot == PCI_SLOT(devfn) && type == rtype) {
> > - *tgt = DT_CPUADDR_TO_TARGET(cpuaddr);
> > - *attr = DT_CPUADDR_TO_ATTR(cpuaddr);
> > + *tgt = DT_CPUADDR_TO_TARGET(range.cpu_addr);
> > + *attr = DT_CPUADDR_TO_ATTR(range.cpu_addr);
> > return 0;
> > }
> > }
> > --
> > 2.45.2
> >
>
> --
> மணிவண்ணன் சதாசிவம்