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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/powerpc/kernel/pci_64.c
parentf09b5ce0184da6a83bac7fafda4e624629272b37 (diff)
downloadblackbird-op-linux-396a1a5832ae28ce2c4150f98827873cbef554f5.tar.gz
blackbird-op-linux-396a1a5832ae28ce2c4150f98827873cbef554f5.zip
[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/powerpc/kernel/pci_64.c')
-rw-r--r--arch/powerpc/kernel/pci_64.c42
1 files changed, 31 insertions, 11 deletions
diff --git a/arch/powerpc/kernel/pci_64.c b/arch/powerpc/kernel/pci_64.c
index 6fa9a0a5c8db..a6b7692c7269 100644
--- a/arch/powerpc/kernel/pci_64.c
+++ b/arch/powerpc/kernel/pci_64.c
@@ -682,7 +682,7 @@ int pci_proc_domain(struct pci_bus *bus)
* Returns negative error code on failure, zero on success.
*/
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_host(dev->bus);
@@ -694,7 +694,9 @@ 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 = (unsigned long)hose->io_base_virt - pci_io_base;
@@ -762,9 +764,6 @@ static pgprot_t __pci_mmap_set_pgprot(struct pci_dev *dev, struct resource *rp,
else
prot |= _PAGE_GUARDED;
- printk(KERN_DEBUG "PCI map for %s:%lx, prot: %lx\n", pci_name(dev), rp->start,
- prot);
-
return __pgprot(prot);
}
@@ -832,7 +831,7 @@ pgprot_t pci_phys_mem_access_prot(struct file *file,
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;
@@ -1333,20 +1332,41 @@ EXPORT_SYMBOL(pci_read_irq_line);
void pci_resource_to_user(const struct pci_dev *dev, int bar,
const struct resource *rsrc,
- u64 *start, u64 *end)
+ resource_size_t *start, resource_size_t *end)
{
struct pci_controller *hose = pci_bus_to_host(dev->bus);
- unsigned long offset = 0;
+ resource_size_t offset = 0;
if (hose == NULL)
return;
if (rsrc->flags & IORESOURCE_IO)
- offset = pci_io_base - (unsigned long)hose->io_base_virt +
- hose->io_base_phys;
+ offset = (unsigned long)hose->io_base_virt - pci_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;
}
struct pci_controller* pci_find_hose_for_OF_device(struct device_node* node)
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