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Subject[PATCH v1 3/4] powerpc/pci: Implement pci_resource_to_user() with pcibios_resource_to_bus()
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"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>
---
arch/powerpc/kernel/pci-common.c | 42 +++++++++++++-------------------------
1 file changed, 14 insertions(+), 28 deletions(-)

diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 8c6beb0..6de6e0e 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -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 !
- *
- * 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().
+ /* 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!
*
- * 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;
}

/**
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