mcb: mcb-pci: Only remap the 1st 0x200 bytes of BAR 0

Currently it is not possible to have a kernel with built-in MCB attached
devices. This results out of the fact that mcb-pci requests PCI BAR 0, then
parses the chameleon table and calls the driver's probe function before
releasing BAR 0 again. When building the kernel with modules this is not a
problem (and therefore it wasn't detected by my tests yet).

A solution is to only remap the 1st 0x200 bytes of a Chameleon PCI device.
0x200 bytes is the maximum size of a Chameleon v2 Table.

Also this patch stops disabling the PCI device on successful registration of MCB
devices.

Signed-off-by: Johannes Thumshirn <johannes.thumshirn@men.de>
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2 files changed, 19 insertions, 9 deletions

diff --git a/drivers/mcb/mcb-internal.h b/drivers/mcb/mcb-internal.h
index f956ef26c0ce..fb7493dcfb79 100644
--- a/drivers/mcb/mcb-internal.h
+++ b/drivers/mcb/mcb-internal.h
@@ -7,6 +7,7 @@
 #define PCI_DEVICE_ID_MEN_CHAMELEON     0x4d45
 #define CHAMELEON_FILENAME_LEN          12
 #define CHAMELEONV2_MAGIC               0xabce
+#define CHAM_HEADER_SIZE                0x200
 
 enum chameleon_descriptor_type {
         CHAMELEON_DTYPE_GENERAL = 0x0,
diff --git a/drivers/mcb/mcb-pci.c b/drivers/mcb/mcb-pci.c
index b59181965643..5e1bd5db02c8 100644
--- a/drivers/mcb/mcb-pci.c
+++ b/drivers/mcb/mcb-pci.c
@@ -17,6 +17,7 @@
 
 struct priv {
         struct mcb_bus *bus;
+        phys_addr_t mapbase;
         void __iomem *base;
 };
 
@@ -31,8 +32,8 @@ static int mcb_pci_get_irq(struct mcb_device *mdev)
 
 static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
+        struct resource *res;
         struct priv *priv;
-        phys_addr_t mapbase;
         int ret;
         int num_cells;
         unsigned long flags;
@@ -47,19 +48,21 @@ static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
                 return -ENODEV;
         }
 
-        mapbase = pci_resource_start(pdev, 0);
-        if (!mapbase) {
+        priv->mapbase = pci_resource_start(pdev, 0);
+        if (!priv->mapbase) {
                 dev_err(&pdev->dev, "No PCI resource\n");
                 goto err_start;
         }
 
-        ret = pci_request_region(pdev, 0, KBUILD_MODNAME);
-        if (ret) {
-                dev_err(&pdev->dev, "Failed to request PCI BARs\n");
+        res = request_mem_region(priv->mapbase, CHAM_HEADER_SIZE,
+                                 KBUILD_MODNAME);
+        if (IS_ERR(res)) {
+                dev_err(&pdev->dev, "Failed to request PCI memory\n");
+                ret = PTR_ERR(res);
                 goto err_start;
         }
 
-        priv->base = pci_iomap(pdev, 0, 0);
+        priv->base = ioremap(priv->mapbase, CHAM_HEADER_SIZE);
         if (!priv->base) {
                 dev_err(&pdev->dev, "Cannot ioremap\n");
                 ret = -ENOMEM;
@@ -84,7 +87,7 @@ static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
         priv->bus->get_irq = mcb_pci_get_irq;
 
-        ret = chameleon_parse_cells(priv->bus, mapbase, priv->base);
+        ret = chameleon_parse_cells(priv->bus, priv->mapbase, priv->base);
         if (ret < 0)
                 goto err_drvdata;
         num_cells = ret;
@@ -93,8 +96,10 @@ static int mcb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
         mcb_bus_add_devices(priv->bus);
 
+        return 0;
+
 err_drvdata:
-        pci_iounmap(pdev, priv->base);
+        iounmap(priv->base);
 err_ioremap:
         pci_release_region(pdev, 0);
 err_start:
@@ -107,6 +112,10 @@ static void mcb_pci_remove(struct pci_dev *pdev)
         struct priv *priv = pci_get_drvdata(pdev);
 
         mcb_release_bus(priv->bus);
+
+        iounmap(priv->base);
+        release_region(priv->mapbase, CHAM_HEADER_SIZE);
+        pci_disable_device(pdev);
 }
 
 static const struct pci_device_id mcb_pci_tbl[] = {