From 4553f733c68b66ef49f838aa24470d58caf76ff5 Mon Sep 17 00:00:00 2001
From: Thierry Reding <treding@nvidia.com>
Date: Mon, 19 Jan 2015 16:15:04 +0100
Subject: [PATCH] drm/tegra: gem: Take into account IOMMU aperture
The IOMMU may not always be able to address 2 GiB of memory. On Tegra20,
the GART supports 32 MiB starting at 0x58000000. Also the aperture on
Tegra30 and later is in fact the full 4 GiB, rather than just 2 GiB as
currently assumed.
Signed-off-by: Thierry Reding <treding@nvidia.com>
---
drivers/gpu/drm/tegra/drm.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index 1833abd7d3aaf..106208463b37a 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -124,14 +124,22 @@ static int tegra_drm_load(struct drm_device *drm, unsigned long flags)
return -ENOMEM;
if (iommu_present(&platform_bus_type)) {
+ struct iommu_domain_geometry *geometry;
+ u64 start, end;
+
tegra->domain = iommu_domain_alloc(&platform_bus_type);
if (!tegra->domain) {
err = -ENOMEM;
goto free;
}
- DRM_DEBUG("IOMMU context initialized\n");
- drm_mm_init(&tegra->mm, 0, SZ_2G);
+ geometry = &tegra->domain->geometry;
+ start = geometry->aperture_start;
+ end = geometry->aperture_end;
+
+ DRM_DEBUG("IOMMU context initialized (aperture: %#llx-%#llx)\n",
+ start, end);
+ drm_mm_init(&tegra->mm, start, end - start + 1);
}
mutex_init(&tegra->clients_lock);
--
2.30.2