powerpc/powernv: Fix endian bug in LPC bus debugfs accessors

When reading from the LPC, the OPAL FW calls return the value via pointer
to a uint32_t which is always returned big endian. Our internal inb/outb
implementation byteswaps that fine but our debugfs code is still broken.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: <stable@vger.kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

1 files changed, 3 insertions, 1 deletions

diff --git a/arch/powerpc/platforms/powernv/opal-lpc.c b/arch/powerpc/platforms/powernv/opal-lpc.c
index ad4b31df779a..dd2c285ad170 100644
--- a/arch/powerpc/platforms/powernv/opal-lpc.c
+++ b/arch/powerpc/platforms/powernv/opal-lpc.c
@@ -191,6 +191,7 @@ static ssize_t lpc_debug_read(struct file *filp, char __user *ubuf,
 {
         struct lpc_debugfs_entry *lpc = filp->private_data;
         u32 data, pos, len, todo;
+        __be32 bedata;
         int rc;
 
         if (!access_ok(VERIFY_WRITE, ubuf, count))
@@ -213,9 +214,10 @@ static ssize_t lpc_debug_read(struct file *filp, char __user *ubuf,
                                 len = 2;
                 }
                 rc = opal_lpc_read(opal_lpc_chip_id, lpc->lpc_type, pos,
-                                   &data, len);
+                                   &bedata, len);
                 if (rc)
                         return -ENXIO;
+                data = be32_to_cpu(bedata);
                 switch(len) {
                 case 4:
                         rc = __put_user((u32)data, (u32 __user *)ubuf);