Staging: vme: Allow size of 0 when disabling a window

The TSI148 driver currently does not allow a size of zero to be passed to a
window. Zero is a valid value if the window is being disabled. Allow
windows to be disabled and their registers cleared.

Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 34 insertions, 22 deletions

diff --git a/drivers/staging/vme/bridges/vme_tsi148.c b/drivers/staging/vme/bridges/vme_tsi148.c
index 5b5c73ec103..03eb48e4d8f 100644
--- a/drivers/staging/vme/bridges/vme_tsi148.c
+++ b/drivers/staging/vme/bridges/vme_tsi148.c
@@ -846,7 +846,7 @@ static int tsi148_alloc_resource(struct vme_master_resource *image,
                 image->pci_resource.start);
 
         /* If the existing size is OK, return */
-        if (existing_size == (size - 1))
+        if ((size != 0) && (existing_size == (size - 1)))
                 return 0;
 
         if (existing_size != 0) {
@@ -858,6 +858,11 @@ static int tsi148_alloc_resource(struct vme_master_resource *image,
                 memset(&(image->pci_resource), 0, sizeof(struct resource));
         }
 
+        /* Exit here if size is zero */
+        if (size == 0) {
+                return 0;
+        }
+
         if (image->pci_resource.name == NULL) {
                 image->pci_resource.name = kmalloc(VMENAMSIZ+3, GFP_KERNEL);
                 if (image->pci_resource.name == NULL) {
@@ -936,12 +941,13 @@ int tsi148_master_set( struct vme_master_resource *image, int enabled,
 
         /* Verify input data */
         if (vme_base & 0xFFFF) {
-                printk("Invalid VME Window alignment\n");
+                printk(KERN_ERR "Invalid VME Window alignment\n");
                 retval = -EINVAL;
                 goto err_window;
         }
-        if (size < 0x10000) {
-                printk("Invalid VME Window size\n");
+
+        if ((size == 0) && (enabled != 0)) {
+                printk(KERN_ERR "Size must be non-zero for enabled windows\n");
                 retval = -EINVAL;
                 goto err_window;
         }
@@ -949,26 +955,31 @@ int tsi148_master_set( struct vme_master_resource *image, int enabled,
         spin_lock(&(image->lock));
 
         /* Let's allocate the resource here rather than further up the stack as
-         * it avoids pushing loads of bus dependant stuff up the stack
+         * it avoids pushing loads of bus dependant stuff up the stack. If size
+         * is zero, any existing resource will be freed.
          */
         retval = tsi148_alloc_resource(image, size);
         if (retval) {
                 spin_unlock(&(image->lock));
-                printk(KERN_ERR "Unable to allocate memory for resource "
-                        "name\n");
-                retval = -ENOMEM;
+                printk(KERN_ERR "Unable to allocate memory for "
+                        "resource\n");
                 goto err_res;
         }
 
-        pci_base = (unsigned long long)image->pci_resource.start;
-
+        if (size == 0) {
+                pci_base = 0;
+                pci_bound = 0;
+                vme_offset = 0;
+        } else {
+                pci_base = (unsigned long long)image->pci_resource.start;
 
-        /*
-         * Bound address is a valid address for the window, adjust
-         * according to window granularity.
-         */
-        pci_bound = pci_base + (size - 0x10000);
-        vme_offset = vme_base - pci_base;
+                /*
+                 * Bound address is a valid address for the window, adjust
+                 * according to window granularity.
+                 */
+                pci_bound = pci_base + (size - 0x10000);
+                vme_offset = vme_base - pci_base;
+        }
 
         /* Convert 64-bit variables to 2x 32-bit variables */
         reg_split(pci_base, &pci_base_high, &pci_base_low);
@@ -977,19 +988,19 @@ int tsi148_master_set( struct vme_master_resource *image, int enabled,
 
         if (pci_base_low & 0xFFFF) {
                 spin_unlock(&(image->lock));
-                printk("Invalid PCI base alignment\n");
+                printk(KERN_ERR "Invalid PCI base alignment\n");
                 retval = -EINVAL;
                 goto err_gran;
         }
         if (pci_bound_low & 0xFFFF) {
                 spin_unlock(&(image->lock));
-                printk("Invalid PCI bound alignment\n");
+                printk(KERN_ERR "Invalid PCI bound alignment\n");
                 retval = -EINVAL;
                 goto err_gran;
         }
         if (vme_offset_low & 0xFFFF) {
                 spin_unlock(&(image->lock));
-                printk("Invalid VME Offset alignment\n");
+                printk(KERN_ERR "Invalid VME Offset alignment\n");
                 retval = -EINVAL;
                 goto err_gran;
         }
@@ -1049,7 +1060,8 @@ int tsi148_master_set( struct vme_master_resource *image, int enabled,
                 temp_ctl |= TSI148_LCSR_OTAT_TM_2eSST;
         }
         if (cycle & VME_2eSSTB) {
-                printk("Currently not setting Broadcast Select Registers\n");
+                printk(KERN_WARNING "Currently not setting Broadcast Select "
+                        "Registers\n");
                 temp_ctl &= ~TSI148_LCSR_OTAT_TM_M;
                 temp_ctl |= TSI148_LCSR_OTAT_TM_2eSSTB;
         }
@@ -1065,7 +1077,7 @@ int tsi148_master_set( struct vme_master_resource *image, int enabled,
                 break;
         default:
                 spin_unlock(&(image->lock));
-                printk("Invalid data width\n");
+                printk(KERN_ERR "Invalid data width\n");
                 retval = -EINVAL;
                 goto err_dwidth;
         }
@@ -1102,7 +1114,7 @@ int tsi148_master_set( struct vme_master_resource *image, int enabled,
                 break;
         default:
                 spin_unlock(&(image->lock));
-                printk("Invalid address space\n");
+                printk(KERN_ERR "Invalid address space\n");
                 retval = -EINVAL;
                 goto err_aspace;
                 break;