[PATCH] ntb: initialize max_mw for Atom before using it

[Daniel Verkamp <daniel.verkamp@intel.com>]

Commit ab760a0 (ntb: Adding split BAR support for Haswell platforms)
changed ntb_device's mw from a fixed-size array into a pointer that is
allocated based on limits.max_mw; however, on Atom platforms, max_mw
is not initialized until ntb_device_setup(), which happens after the
allocation.

Fill out max_mw in ntb_atom_detect() to match ntb_xeon_detect(); this
happens before the use of max_mw in the ndev->mw allocation.

Fixes a null pointer dereference on Atom platforms with ntb hardware.

v2: fix typo (mw_max should be max_mw)

Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Acked-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>
---

Resend with patch inline on Dave's request.

Applies to 4.0.y, 3.19.y, and 3.18.y.

---
 drivers/ntb/ntb_hw.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c
index b5c8707..15f9b7c 100644
--- a/drivers/ntb/ntb_hw.c
+++ b/drivers/ntb/ntb_hw.c
@@ -1660,6 +1660,7 @@ static int ntb_atom_detect(struct ntb_device *ndev)
 	u32 ppd;
 
 	ndev->hw_type = BWD_HW;
+	ndev->limits.max_mw = BWD_MAX_MW;
 
 	rc = pci_read_config_dword(ndev->pdev, NTB_PPD_OFFSET, &ppd);
 	if (rc)
-- 
2.4.3