1 files changed, 20 insertions, 27 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index b9234c43f43d..39b033b441d2 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -251,28 +251,23 @@ void radeon_scratch_free(struct radeon_device *rdev, uint32_t reg)
  */
 int radeon_doorbell_init(struct radeon_device *rdev)
 {
-        int i;
-
         /* doorbell bar mapping */
         rdev->doorbell.base = pci_resource_start(rdev->pdev, 2);
         rdev->doorbell.size = pci_resource_len(rdev->pdev, 2);
 
-        /* limit to 4 MB for now */
-        if (rdev->doorbell.size > (4 * 1024 * 1024))
-                rdev->doorbell.size = 4 * 1024 * 1024;
+        rdev->doorbell.num_doorbells = min_t(u32, rdev->doorbell.size / sizeof(u32), RADEON_MAX_DOORBELLS);
+        if (rdev->doorbell.num_doorbells == 0)
+                return -EINVAL;
 
-        rdev->doorbell.ptr = ioremap(rdev->doorbell.base, rdev->doorbell.size);
+        rdev->doorbell.ptr = ioremap(rdev->doorbell.base, rdev->doorbell.num_doorbells * sizeof(u32));
         if (rdev->doorbell.ptr == NULL) {
                 return -ENOMEM;
         }
         DRM_INFO("doorbell mmio base: 0x%08X\n", (uint32_t)rdev->doorbell.base);
         DRM_INFO("doorbell mmio size: %u\n", (unsigned)rdev->doorbell.size);
 
-        rdev->doorbell.num_pages = rdev->doorbell.size / PAGE_SIZE;
+        memset(&rdev->doorbell.used, 0, sizeof(rdev->doorbell.used));
 
-        for (i = 0; i < rdev->doorbell.num_pages; i++) {
-                rdev->doorbell.free[i] = true;
-        }
         return 0;
 }
 
@@ -290,40 +285,38 @@ void radeon_doorbell_fini(struct radeon_device *rdev)
 }
 
 /**
- * radeon_doorbell_get - Allocate a doorbell page
+ * radeon_doorbell_get - Allocate a doorbell entry
  *
  * @rdev: radeon_device pointer
- * @doorbell: doorbell page number
+ * @doorbell: doorbell index
  *
- * Allocate a doorbell page for use by the driver (all asics).
+ * Allocate a doorbell for use by the driver (all asics).
  * Returns 0 on success or -EINVAL on failure.
  */
 int radeon_doorbell_get(struct radeon_device *rdev, u32 *doorbell)
 {
-        int i;
-
-        for (i = 0; i < rdev->doorbell.num_pages; i++) {
-                if (rdev->doorbell.free[i]) {
-                        rdev->doorbell.free[i] = false;
-                        *doorbell = i;
-                        return 0;
-                }
+        unsigned long offset = find_first_zero_bit(rdev->doorbell.used, rdev->doorbell.num_doorbells);
+        if (offset < rdev->doorbell.num_doorbells) {
+                __set_bit(offset, rdev->doorbell.used);
+                *doorbell = offset;
+                return 0;
+        } else {
+                return -EINVAL;
         }
-        return -EINVAL;
 }
 
 /**
- * radeon_doorbell_free - Free a doorbell page
+ * radeon_doorbell_free - Free a doorbell entry
  *
  * @rdev: radeon_device pointer
- * @doorbell: doorbell page number
+ * @doorbell: doorbell index
  *
- * Free a doorbell page allocated for use by the driver (all asics)
+ * Free a doorbell allocated for use by the driver (all asics)
  */
 void radeon_doorbell_free(struct radeon_device *rdev, u32 doorbell)
 {
-        if (doorbell < rdev->doorbell.num_pages)
-                rdev->doorbell.free[doorbell] = true;
+        if (doorbell < rdev->doorbell.num_doorbells)
+                __clear_bit(doorbell, rdev->doorbell.used);
 }
 
 /*