[PATCH 3/3 REPOST #2] alpha, drm: Add Alpha support to Radeon DRM code

[Jay Estabrook]

Alpha needs to have available the system bus address for the Radeon's
local memory, so that it can be used in ttm_bo_vm_fault(), when building
the PTEs for accessing that VRAM.  So, we make bus.addr hold the ioremap()
return, and then we can modify bus.base appropriately for use during page
fault processing.

Signed-off-by: Jay Estabrook <jay.estabrook at gmail.com>
---
 drivers/gpu/drm/radeon/radeon_ttm.c |   23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff -Naurp a/drivers/gpu/drm/radeon/radeon_ttm.c 
b/drivers/gpu/drm/radeon/radeon_ttm.c
--- a/drivers/gpu/drm/radeon/radeon_ttm.c       2011-04-26 23:48:50.000000000 
-0400
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c       2011-05-03 18:24:27.000000000 
-0400
@@ -450,6 +450,29 @@ static int radeon_ttm_io_mem_reserve(str
                        return -EINVAL;
                mem->bus.base = rdev->mc.aper_base;
                mem->bus.is_iomem = true;
+#ifdef __alpha__
+               /*
+                * Alpha: use bus.addr to hold the ioremap() return,
+                * so we can modify bus.base below.
+                */
+               if (mem->placement & TTM_PL_FLAG_WC)
+                       mem->bus.addr =
+                               ioremap_wc(mem->bus.base + mem->bus.offset,
+                                          mem->bus.size);
+               else
+                       mem->bus.addr =
+                               ioremap_nocache(mem->bus.base + mem->bus.offset,
+                                               mem->bus.size);
+
+               /*
+                * Alpha: Use just the bus offset plus
+                * the hose/domain memory base for bus.base.
+                * It then can be used to build PTEs for VRAM
+                * access, as done in ttm_bo_vm_fault().
+                */
+               mem->bus.base = (mem->bus.base & 0x0ffffffffUL) +
+                       rdev->ddev->hose->dense_mem_base;
+#endif
                break;
        default:
                return -EINVAL;