[PATCH v5 1/2] PCI: dwc: Fix a 64bit bug in dw_pcie_ep_raise_msix_irq()

From: Dan Carpenter
Date: Fri Jan 26 2024 - 04:22:00 EST


The "msg_addr" variable is u64. However, the "aligned_offset" is an
unsigned int. This means that when the code does:

msg_addr &= ~aligned_offset;

it will unintentionally zero out the high 32 bits. Use ALIGN_DOWN()
to do the alignment instead.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 2217fffcd63f ("PCI: dwc: endpoint: Fix dw_pcie_ep_raise_msix_irq() alignment support")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Niklas Cassel <cassel@xxxxxxxxxx>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
v5: Add the #include.
v4: Add stable and r-b from Niklas
v3: Use ALIGN_DOWN()
v2: fix typo in commit message

drivers/pci/controller/dwc/pcie-designware-ep.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 5befed2dc02b..d6b66597101e 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -6,6 +6,7 @@
* Author: Kishon Vijay Abraham I <kishon@xxxxxx>
*/

+#include <linux/align.h>
#include <linux/bitfield.h>
#include <linux/of.h>
#include <linux/platform_device.h>
@@ -551,7 +552,7 @@ int dw_pcie_ep_raise_msix_irq(struct dw_pcie_ep *ep, u8 func_no,
}

aligned_offset = msg_addr & (epc->mem->window.page_size - 1);
- msg_addr &= ~aligned_offset;
+ msg_addr = ALIGN_DOWN(msg_addr, epc->mem->window.page_size);
ret = dw_pcie_ep_map_addr(epc, func_no, 0, ep->msi_mem_phys, msg_addr,
epc->mem->window.page_size);
if (ret)
--
2.43.0