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powerpc/pci: Implement pci_resource_to_user() with pcibios_resource_to_bus() 

"User" addresses are shown in /sys/devices/pci.../.../resource and
/proc/bus/pci/devices and used as mmap offsets for /proc/bus/pci/BB/DD.F
files.  For I/O port resources on powerpc, these are PCI bus addresses,
i.e., raw BAR values.

Previously pci_resource_to_user() computed the user address by subtracting
"hose->io_base_virt - _IO_BASE" from the resource start:

  pci_resource_to_user()
    if (IO)
      offset = (unsigned long)hose->io_base_virt - _IO_BASE;
    *start = rsrc->start - offset;

We've already told the PCI core about that "hose->io_base_virt - _IO_BASE"
offset:

  pcibios_setup_phb_resources()
    res = &hose->io_resource;
    offset = pcibios_io_space_offset();
    /* i.e., "offset = hose->io_base_virt - _IO_BASE" */
    pci_add_resource_offset(resources, res, offset);

so pcibios_resource_to_bus() knows how to do that translation.

No functional change intended.

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Yinghai Lu <yinghai@kernel.org>
This commit is contained in:
Bjorn Helgaas 2016-06-17 14:43:34 -05:00
parent 0ad8f06d58
commit 3830135857
1 changed files with 14 additions and 28 deletions
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42
arch/powerpc/kernel/pci-common.c
View File

@ -581,39 +581,25 @@ void pci_resource_to_user(const struct pci_dev *dev, int bar,
const struct resource *rsrc,
resource_size_t *start, resource_size_t *end)
{
struct pci_controller *hose = pci_bus_to_host(dev->bus);
resource_size_t offset = 0;
struct pci_bus_region region;
if (hose == NULL)
if (rsrc->flags & IORESOURCE_IO) {
pcibios_resource_to_bus(dev->bus, &region,
(struct resource *) rsrc);
*start = region.start;
*end = region.end;
return;
}
if (rsrc->flags & IORESOURCE_IO)
offset = (unsigned long)hose->io_base_virt - _IO_BASE;
/* We pass a fully fixed up address to userland for MMIO instead of
* a BAR value because X is lame and expects to be able to use that
* to pass to /dev/mem !
/* We pass a CPU physical address to userland for MMIO instead of a
* BAR value because X is lame and expects to be able to use that
* to pass to /dev/mem!
*
* That means that we'll have potentially 64 bits values where some
* userland apps only expect 32 (like X itself since it thinks only
* Sparc has 64 bits MMIO) but if we don't do that, we break it on
* 32 bits CHRPs :-(
*
* Hopefully, the sysfs insterface is immune to that gunk. Once X
* has been fixed (and the fix spread enough), we can re-enable the
* 2 lines below and pass down a BAR value to userland. In that case
* we'll also have to re-enable the matching code in
* __pci_mmap_make_offset().
*
* BenH.
* That means we may have 64-bit values where some apps only expect
* 32 (like X itself since it thinks only Sparc has 64-bit MMIO).
*/
#if 0
else if (rsrc->flags & IORESOURCE_MEM)
offset = hose->pci_mem_offset;
#endif
*start = rsrc->start - offset;
*end = rsrc->end - offset;
*start = rsrc->start;
*end = rsrc->end;
}
/**