[PATCH 3.19.y-ckt 042/251] of/pci: Fix pci_address_to_pio() conversion of CPU address to I/O port

[Kamal Mostafa]

3.19.8-ckt4 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Zhichang Yuan <yuanzhichang at hisilicon.com>

commit 5dbb4c6167229c8d4f528e8ec26699a7305000a3 upstream.

41f8bba7f555 ("of/pci: Add pci_register_io_range() and
pci_pio_to_address()") added support for systems with several I/O ranges
described by OF bindings.  It modified pci_address_to_pio() look up the
io_range for a given CPU physical address, but the conversion was wrong.

Fix the conversion of address to I/O port.

[bhelgaas: changelog]
Fixes: 41f8bba7f555 ("of/pci: Add pci_register_io_range() and pci_pio_to_address()")
Signed-off-by: Zhichang Yuan <yuanzhichang at hisilicon.com>
Signed-off-by: Bjorn Helgaas <bhelgaas at google.com>
Acked-by: Liviu Dudau <Liviu.Dudau at arm.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/of/address.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 78a7dcb..6906a3f 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -765,7 +765,7 @@ unsigned long __weak pci_address_to_pio(phys_addr_t address)
 	spin_lock(&io_range_lock);
 	list_for_each_entry(res, &io_range_list, list) {
 		if (address >= res->start && address < res->start + res->size) {
-			addr = res->start - address + offset;
+			addr = address - res->start + offset;
 			break;
 		}
 		offset += res->size;
-- 
1.9.1