From 396a1a5832ae28ce2c4150f98827873cbef554f5 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Fri, 8 Dec 2006 17:14:33 +1100 Subject: [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 Signed-off-by: Paul Mackerras --- arch/ppc/kernel/pci.c | 41 ++++++++++++++++++++++++++++++++--------- 1 file changed, 32 insertions(+), 9 deletions(-) (limited to 'arch/ppc/kernel') diff --git a/arch/ppc/kernel/pci.c b/arch/ppc/kernel/pci.c index 63808e01cb0..5e723c4c257 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; -- cgit v1.2.3-18-g5258