PCI/alpha: pci sysfs resources

This closes http://bugzilla.kernel.org/show_bug.cgi?id=10893
which is a showstopper for X development on alpha.

The generic HAVE_PCI_MMAP code (drivers/pci-sysfs.c) is not
very useful since we have to deal with three different types
of MMIO address spaces: sparse and dense mappings for old
ev4/ev5 machines and "normal" 1:1 MMIO space (bwx) for ev56 and
later.
Also "write combine" mappings are meaningless on alpha - roughly
speaking, alpha does write combining, IO reordering and other
optimizations by default, unless user splits IO accesses
with memory barriers.

I think the cleanest way to deal with resource files on alpha
is to convert the default no-op pci_create_resource_files() and
pci_remove_resource_files() for !HAVE_PCI_MMAP case into __weak
functions and override them with alpha specific ones.

Another alpha hook is needed for "legacy_" resource files
to handle sparse addressing (pci_adjust_legacy_attr).

With the "standard" resourceN files on ev56/ev6 libpciaccess
works "out of the box". Handling of resourceN_sparse/resourceN_dense
files on older machines obviously requires some userland work.

Sparse/dense stuff has been tested on sx164 (pca56/pyxis, normally
uses bwx IO) with the kernel hacked into "cia compatible" mode.

Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 17 insertions, 2 deletions

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index dfc4e0d..1c89298 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -493,6 +493,19 @@ pci_mmap_legacy_io(struct kobject *kobj, struct bin_attribute *attr,
 }
 
 /**
+ * pci_adjust_legacy_attr - adjustment of legacy file attributes
+ * @b: bus to create files under
+ * @mmap_type: I/O port or memory
+ *
+ * Stub implementation. Can be overridden by arch if necessary.
+ */
+void __weak
+pci_adjust_legacy_attr(struct pci_bus *b, enum pci_mmap_state mmap_type)
+{
+	return;
+}
+
+/**
  * pci_create_legacy_files - create legacy I/O port and memory files
  * @b: bus to create files under
  *
@@ -518,6 +531,7 @@ void pci_create_legacy_files(struct pci_bus *b)
 	b->legacy_io->read = pci_read_legacy_io;
 	b->legacy_io->write = pci_write_legacy_io;
 	b->legacy_io->mmap = pci_mmap_legacy_io;
+	pci_adjust_legacy_attr(b, pci_mmap_io);
 	error = device_create_bin_file(&b->dev, b->legacy_io);
 	if (error)
 		goto legacy_io_err;
@@ -528,6 +542,7 @@ void pci_create_legacy_files(struct pci_bus *b)
 	b->legacy_mem->size = 1024*1024;
 	b->legacy_mem->attr.mode = S_IRUSR | S_IWUSR;
 	b->legacy_mem->mmap = pci_mmap_legacy_mem;
+	pci_adjust_legacy_attr(b, pci_mmap_mem);
 	error = device_create_bin_file(&b->dev, b->legacy_mem);
 	if (error)
 		goto legacy_mem_err;
@@ -719,8 +734,8 @@ static int pci_create_resource_files(struct pci_dev *pdev)
 	return 0;
 }
 #else /* !HAVE_PCI_MMAP */
-static inline int pci_create_resource_files(struct pci_dev *dev) { return 0; }
-static inline void pci_remove_resource_files(struct pci_dev *dev) { return; }
+int __weak pci_create_resource_files(struct pci_dev *dev) { return 0; }
+void __weak pci_remove_resource_files(struct pci_dev *dev) { return; }
 #endif /* HAVE_PCI_MMAP */
 
 /**