+/**
+ * r600_vram_gtt_location - try to find VRAM & GTT location
+ * @rdev: radeon device structure holding all necessary informations
+ * @mc: memory controller structure holding memory informations
+ *
+ * Function will place try to place VRAM at same place as in CPU (PCI)
+ * address space as some GPU seems to have issue when we reprogram at
+ * different address space.
+ *
+ * If there is not enough space to fit the unvisible VRAM after the
+ * aperture then we limit the VRAM size to the aperture.
+ *
+ * If we are using AGP then place VRAM adjacent to AGP aperture are we need
+ * them to be in one from GPU point of view so that we can program GPU to
+ * catch access outside them (weird GPU policy see ??).
+ *
+ * This function will never fails, worst case are limiting VRAM or GTT.
+ *
+ * Note: GTT start, end, size should be initialized before calling this
+ * function on AGP platform.
+ */
+void r600_vram_gtt_location(struct radeon_device *rdev, struct radeon_mc *mc)
+{
+ u64 size_bf, size_af;
+
+ if (mc->mc_vram_size > 0xE0000000) {
+ /* leave room for at least 512M GTT */
+ dev_warn(rdev->dev, "limiting VRAM\n");
+ mc->real_vram_size = 0xE0000000;
+ mc->mc_vram_size = 0xE0000000;
+ }
+ if (rdev->flags & RADEON_IS_AGP) {
+ size_bf = mc->gtt_start;
+ size_af = 0xFFFFFFFF - mc->gtt_end + 1;
+ if (size_bf > size_af) {
+ if (mc->mc_vram_size > size_bf) {
+ dev_warn(rdev->dev, "limiting VRAM\n");
+ mc->real_vram_size = size_bf;
+ mc->mc_vram_size = size_bf;
+ }
+ mc->vram_start = mc->gtt_start - mc->mc_vram_size;
+ } else {
+ if (mc->mc_vram_size > size_af) {
+ dev_warn(rdev->dev, "limiting VRAM\n");
+ mc->real_vram_size = size_af;
+ mc->mc_vram_size = size_af;
+ }
+ mc->vram_start = mc->gtt_end;
+ }
+ mc->vram_end = mc->vram_start + mc->mc_vram_size - 1;
+ dev_info(rdev->dev, "VRAM: %lluM 0x%08llX - 0x%08llX (%lluM used)\n",
+ mc->mc_vram_size >> 20, mc->vram_start,
+ mc->vram_end, mc->real_vram_size >> 20);
+ } else {
+ u64 base = 0;
+ if (rdev->flags & RADEON_IS_IGP)
+ base = (RREG32(MC_VM_FB_LOCATION) & 0xFFFF) << 24;
+ radeon_vram_location(rdev, &rdev->mc, base);
+ radeon_gtt_location(rdev, mc);
+ }
+}
+