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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2006-12-08 17:14:33 +1100
committerPaul Mackerras <paulus@samba.org>2006-12-08 17:21:06 +1100
commit396a1a5832ae28ce2c4150f98827873cbef554f5 (patch)
tree26d72bdf3765184f64e6231e7962152272584401 /arch/ppc/kernel
parentf09b5ce0184da6a83bac7fafda4e624629272b37 (diff)
downloadlinux-linaro-stable-396a1a5832ae28ce2c4150f98827873cbef554f5.tar.gz
[POWERPC] Fix mmap of PCI resource with hack for X
The powerpc version of pci_resource_to_user() and associated hooks used by /proc/bus/pci and /sys/bus/pci mmap have been broken for some time on machines that don't have a 1:1 mapping of devices (basically on non-PowerMacs) and have PCI devices above 32 bits. This attempts to fix it as well as possible. The rule is supposed to be that pci_resource_to_user() always converts the resources back into a BAR values since that's what the /proc interface was supposed to deal with. However, for X to work on platforms where PCI MMIO is not mapped 1:1, it became a habit of platforms like powerpc to pass "fixed up" values there since X expects to be able to use values from /proc/bus/pci/devices as offsets to mmap of /dev/mem... So we keep that contraption here, causing also /sys/*/resource to expose fully absolute MMIO addresses instead of BAR values, which is ugly, but should still work as long as those are only used to calculate alignment within a page. X is still broken when built 32 bits on machines where PCI MMIO can be above 32-bit space unfortunately. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/ppc/kernel')
-rw-r--r--arch/ppc/kernel/pci.c41
1 files changed, 32 insertions, 9 deletions
diff --git a/arch/ppc/kernel/pci.c b/arch/ppc/kernel/pci.c
index 63808e01cb0b..5e723c4c2571 100644
--- a/arch/ppc/kernel/pci.c
+++ b/arch/ppc/kernel/pci.c
@@ -879,7 +879,7 @@ pci_resource_to_bus(struct pci_dev *pdev, struct resource *res)
static struct resource *__pci_mmap_make_offset(struct pci_dev *dev,
- unsigned long *offset,
+ resource_size_t *offset,
enum pci_mmap_state mmap_state)
{
struct pci_controller *hose = pci_bus_to_hose(dev->bus->number);
@@ -891,7 +891,9 @@ static struct resource *__pci_mmap_make_offset(struct pci_dev *dev,
/* If memory, add on the PCI bridge address offset */
if (mmap_state == pci_mmap_mem) {
+#if 0 /* See comment in pci_resource_to_user() for why this is disabled */
*offset += hose->pci_mem_offset;
+#endif
res_bit = IORESOURCE_MEM;
} else {
io_offset = hose->io_base_virt - ___IO_BASE;
@@ -1030,7 +1032,7 @@ int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
enum pci_mmap_state mmap_state,
int write_combine)
{
- unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+ resource_size_t offset = vma->vm_pgoff << PAGE_SHIFT;
struct resource *rp;
int ret;
@@ -1132,21 +1134,42 @@ void pci_resource_to_user(const struct pci_dev *dev, int bar,
resource_size_t *start, resource_size_t *end)
{
struct pci_controller *hose = pci_bus_to_hose(dev->bus->number);
- unsigned long offset = 0;
+ resource_size_t offset = 0;
if (hose == NULL)
return;
if (rsrc->flags & IORESOURCE_IO)
- offset = ___IO_BASE - hose->io_base_virt + hose->io_base_phys;
+ 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().
+ *
+ * BenH.
+ */
+#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 - offset;
+ *end = rsrc->end - offset;
}
-void __init
-pci_init_resource(struct resource *res, unsigned long start, unsigned long end,
- int flags, char *name)
+void __init pci_init_resource(struct resource *res, resource_size_t start,
+ resource_size_t end, int flags, char *name)
{
res->start = start;
res->end = end;