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 14866aa22f75363f4c8ed158583fb8203c08a46a..22927c80ff46917205b05082ac213dc98b849bb5 100644 (file)
--- a/drivers/mcb/mcb-pci.c
+++ b/drivers/mcb/mcb-pci.c
@@ -31,7 +31,7 @@ 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);
@@ -90,7 +90,30 @@ 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);