Commit 09752a12 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Jason Cooper
Browse files

bus: mvebu-mbus: Avoid setting an undefined window size

The mbus hardware requires a power of two size, and size aligned base.
Currently, if a non-power of two is passed in to the low level routines
they configure the register in a way that results in undefined behaviour.

Call WARN and return EINVAL instead.

Also, update the debugfs routines to show a message if there is an
invalid register setting.

All together this makes the recent problems with silent failure
of PCI very obvious, noisy and debuggable.
Signed-off-by: default avatarJason Gunthorpe <>
Signed-off-by: default avatarThomas Petazzoni <>

Signed-off-by: default avatarJason Cooper <>
parent b6d07e02
......@@ -56,6 +56,7 @@
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/debugfs.h>
#include <linux/log2.h>
* DDR target is the same on all platforms.
......@@ -266,6 +267,17 @@ static int mvebu_mbus_setup_window(struct mvebu_mbus_state *mbus,
u32 ctrl, remap_addr;
if (!is_power_of_2(size)) {
WARN(true, "Invalid MBus window size: 0x%zx\n", size);
return -EINVAL;
if ((base & (phys_addr_t)(size - 1)) != 0) {
WARN(true, "Invalid MBus base/size: %pa len 0x%zx\n", &base,
return -EINVAL;
ctrl = ((size - 1) & WIN_CTRL_SIZE_MASK) |
(target << WIN_CTRL_TGT_SHIFT) |
......@@ -413,6 +425,10 @@ static int mvebu_devs_debug_show(struct seq_file *seq, void *v)
win, (unsigned long long)wbase,
(unsigned long long)(wbase + wsize), wtarget, wattr);
if (!is_power_of_2(wsize) ||
((wbase & (u64)(wsize - 1)) != 0))
seq_puts(seq, " (Invalid base/size!!)");
if (win < mbus->soc->num_remappable_wins) {
seq_printf(seq, " (remap %016llx)\n",
(unsigned long long)wremap);
Supports Markdown
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment