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From:   Kishon Vijay Abraham I <kishon@ti.com>
To:     Kishon Vijay Abraham I <kishon@ti.com>,
        Jingoo Han <jingoohan1@gmail.com>,
        Gustavo Pimentel <gustavo.pimentel@synopsys.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        Rob Herring <robh@kernel.org>,
        Bjorn Helgaas <bhelgaas@google.com>
CC:     <linux-pci@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        Lokesh Vutla <lokeshvutla@ti.com>
Subject: [PATCH] PCI: designware-ep: Fix NULL pointer dereference error
Date:   Fri, 5 Mar 2021 08:29:10 +0530
Message-ID: <20210305025910.9652-1-kishon@ti.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

commit 281f1f99cf3a ("PCI: dwc: Detect number of iATU windows") detected
the number of inbound and outbound windows dynamically at runtime in
dw_pcie_setup(). However pcie-designware-ep.c accessed the variables
holding the number of inbound and outbound windows even before
dw_pcie_setup() was invoked. Fix the sequence here.

Fixes: 281f1f99cf3a ("PCI: dwc: Detect number of iATU windows")
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
---
 .../pci/controller/dwc/pcie-designware-ep.c   | 44 ++++++++++---------
 1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-ep.c b/drivers/pci/controller/dwc/pcie-designware-ep.c
index 1c25d8337151..2c0f837af458 100644
--- a/drivers/pci/controller/dwc/pcie-designware-ep.c
+++ b/drivers/pci/controller/dwc/pcie-designware-ep.c
@@ -636,9 +636,11 @@ static unsigned int dw_pcie_ep_find_ext_capability(struct dw_pcie *pci, int cap)
 int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
 {
 	struct dw_pcie *pci = to_dw_pcie_from_ep(ep);
+	struct device *dev = pci->dev;
 	unsigned int offset;
 	unsigned int nbars;
 	u8 hdr_type;
+	void *addr;
 	u32 reg;
 	int i;
 
@@ -665,6 +667,27 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
 	}
 
 	dw_pcie_setup(pci);
+
+	ep->ib_window_map = devm_kcalloc(dev,
+					 BITS_TO_LONGS(pci->num_ib_windows),
+					 sizeof(long),
+					 GFP_KERNEL);
+	if (!ep->ib_window_map)
+		return -ENOMEM;
+
+	ep->ob_window_map = devm_kcalloc(dev,
+					 BITS_TO_LONGS(pci->num_ob_windows),
+					 sizeof(long),
+					 GFP_KERNEL);
+	if (!ep->ob_window_map)
+		return -ENOMEM;
+
+	addr = devm_kcalloc(dev, pci->num_ob_windows, sizeof(phys_addr_t),
+			    GFP_KERNEL);
+	if (!addr)
+		return -ENOMEM;
+	ep->outbound_addr = addr;
+
 	dw_pcie_dbi_ro_wr_dis(pci);
 
 	return 0;
@@ -674,7 +697,6 @@ EXPORT_SYMBOL_GPL(dw_pcie_ep_init_complete);
 int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 {
 	int ret;
-	void *addr;
 	u8 func_no;
 	struct resource *res;
 	struct pci_epc *epc;
@@ -712,26 +734,6 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 	ep->phys_base = res->start;
 	ep->addr_size = resource_size(res);
 
-	ep->ib_window_map = devm_kcalloc(dev,
-					 BITS_TO_LONGS(pci->num_ib_windows),
-					 sizeof(long),
-					 GFP_KERNEL);
-	if (!ep->ib_window_map)
-		return -ENOMEM;
-
-	ep->ob_window_map = devm_kcalloc(dev,
-					 BITS_TO_LONGS(pci->num_ob_windows),
-					 sizeof(long),
-					 GFP_KERNEL);
-	if (!ep->ob_window_map)
-		return -ENOMEM;
-
-	addr = devm_kcalloc(dev, pci->num_ob_windows, sizeof(phys_addr_t),
-			    GFP_KERNEL);
-	if (!addr)
-		return -ENOMEM;
-	ep->outbound_addr = addr;
-
 	if (pci->link_gen < 1)
 		pci->link_gen = of_pci_get_max_link_speed(np);
 
-- 
2.17.1