mcb-pci: Reallocate memory region to avoid memory overlapping

[ Upstream commit 9be24faadd085c284890c3afcec7a0184642315a ]

mcb-pci requests a fixed-size memory region to parse the chameleon
table, however, if the chameleon table is smaller that the allocated
region, it could overlap with the IP Cores' memory regions.

After parsing the chameleon table, drop/reallocate the memory region
with the actual chameleon table size.

Co-developed-by: Jorge Sanjuan Garcia <jorge.sanjuangarcia@duagon.com>
Signed-off-by: Jorge Sanjuan Garcia <jorge.sanjuangarcia@duagon.com>
Signed-off-by: Javier Rodriguez <josejavier.rodriguez@duagon.com>
Signed-off-by: Johannes Thumshirn <jth@kernel.org>
Link: https://lore.kernel.org/r/20230411083329.4506-3-jth@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/mcb/mcb-pci.c b/drivers/mcb/mcb-pci.c
index af4d2f26f1c620a9cd0cd600739fd22e2aaee16a..b0ec3bbf1b76d0ff4b8b976cdf3196de40433b08 100644 (file)
--- a/drivers/mcb/mcb-pci.c
+++ b/drivers/mcb/mcb-pci.c
@@ -34,7 +34,7 @@ static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
        struct resource *res;
        struct priv *priv;
-       int ret;
+       int ret, table_size;
        unsigned long flags;
 
        priv = devm_kzalloc(&pdev->dev, sizeof(struct priv), GFP_KERNEL);
@@ -93,7 +93,30 @@ static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
        if (ret < 0)
                goto out_mcb_bus;
 
-       dev_dbg(&pdev->dev, "Found %d cells\n", ret);
+       table_size = ret;
+
+       if (table_size < CHAM_HEADER_SIZE) {
+               /* Release the previous resources */
+               devm_iounmap(&pdev->dev, priv->base);
+               devm_release_mem_region(&pdev->dev, priv->mapbase, CHAM_HEADER_SIZE);
+
+               /* Then, allocate it again with the actual chameleon table size */
+               res = devm_request_mem_region(&pdev->dev, priv->mapbase,
+                                               table_size,
+                                               KBUILD_MODNAME);
+               if (!res) {
+                       dev_err(&pdev->dev, "Failed to request PCI memory\n");
+                       ret = -EBUSY;
+                       goto out_mcb_bus;
+               }
+
+               priv->base = devm_ioremap(&pdev->dev, priv->mapbase, table_size);
+               if (!priv->base) {
+                       dev_err(&pdev->dev, "Cannot ioremap\n");
+                       ret = -ENOMEM;
+                       goto out_mcb_bus;
+               }
+       }
 
        mcb_bus_add_devices(priv->bus);