[PATCH v7 2/6] pci: OF: Fix the conversion of IO ranges into IO resources.

Arnd Bergmann
2014-03-14T18:46:23Z

On Friday 14 March 2014, Liviu Dudau wrote:
> You are right, that was lazy of me. What about this version?

Yes, that seems better. Thanks for fixing it up.

But back to the more important question that I realized we have
not resolved yet:

You now have two completely independent allocation functions for
logical I/O space numbers, and they will return different numbers
for any nontrivial scenario.

> +int of_pci_range_to_resource(struct of_pci_range *range,
> + struct device_node *np, struct resource *res)
> +{
> + res->flags = range->flags;
> + res->parent = res->child = res->sibling = NULL;
> + res->name = np->full_name;
> +
> + if (res->flags & IORESOURCE_IO) {
> + unsigned long port = -1;
> + int err = pci_register_io_range(range->cpu_addr, range->size);
> + if (err)
> + goto invalid_range;
> + port = pci_address_to_pio(range->cpu_addr);
> + if (port == (unsigned long)-1) {
> + err = -EINVAL;
> + goto invalid_range;
> + }
> + res->start = port;
> + } else {

This one concatenates the I/O spaces and assumes that each space starts
at bus address zero, and takes little precaution to avoid filling up IO_SPACE_LIMIT
if the sizes are too big.

>+unsigned long pci_ioremap_io(const struct resource *res, phys_addr_t phys_addr)
>+{
>+ unsigned long start, len, virt_start;
>+ int err;
>+
>+ if (res->end > IO_SPACE_LIMIT)
>+ return -EINVAL;
>+
>+ /*
>+ * try finding free space for the whole size first,
>+ * fall back to 64K if not available
>+ */
>+ len = resource_size(res);
>+ start = bitmap_find_next_zero_area(pci_iospace, IO_SPACE_PAGES,
>+ res->start / PAGE_SIZE, len / PAGE_SIZE, 0);
>+ if (start == IO_SPACE_PAGES && len > SZ_64K) {
>+ len = SZ_64K;
>+ start = 0;
>+ start = bitmap_find_next_zero_area(pci_iospace, IO_SPACE_PAGES,
>+ start, len / PAGE_SIZE, 0);
>+ }
>+
>+ /* no 64K area found */
>+ if (start == IO_SPACE_PAGES)
>+ return -ENOMEM;
>+
>+ /* ioremap physical aperture to virtual aperture */
>+ virt_start = start * PAGE_SIZE + (unsigned long)PCI_IOBASE;
>+ err = ioremap_page_range(virt_start, virt_start + len,
>+ phys_addr, __pgprot(PROT_DEVICE_nGnRE));
>+ if (err)
>+ return err;
>+
>+ bitmap_set(pci_iospace, start, len / PAGE_SIZE);
>+
>+ /* return io_offset */
>+ return start * PAGE_SIZE - res->start;
>+}

While this one will try to fall back to smaller sizes, and will honor nonzero
bus addresses.

I think we shouldn't even try to do the same thing twice, but instead just
use a single allocator. I'd prefer the one I came up with, but I realize
that I am biased here ;-)

Arnd