[PATCH 2/2] drm/i915/gen8: Flip the 48b switch

Michel Thierry
2015-09-30T14:36:22Z

Use 48b addresses if hw supports it (i915.enable_ppgtt=3).
Update the sanitize_enable_ppgtt for 48 bit PPGTT mode.

Note, aliasing PPGTT remains 32b only.

v2: s/full_64b/full_48b/. (Akash)
v3: Add sanitize_enable_ppgtt changes until here. (Akash)
v4: Update param description (Chris)

Cc: Akash Goel <akash.goel@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Michel Thierry <michel.thierry@intel.com>
---
drivers/gpu/drm/i915/i915_gem_gtt.c | 7 ++++++-
drivers/gpu/drm/i915/i915_params.c | 2 +-
2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 47344d0..2d964a7 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -104,9 +104,11 @@ static int sanitize_enable_ppgtt(struct drm_device *dev, int enable_ppgtt)
{
bool has_aliasing_ppgtt;
bool has_full_ppgtt;
+ bool has_full_48bit_ppgtt;

has_aliasing_ppgtt = INTEL_INFO(dev)->gen >= 6;
has_full_ppgtt = INTEL_INFO(dev)->gen >= 7;
+ has_full_48bit_ppgtt = IS_BROADWELL(dev) || INTEL_INFO(dev)->gen >= 9;

if (intel_vgpu_active(dev))
has_full_ppgtt = false; /* emulation is too hard */
@@ -125,6 +127,9 @@ static int sanitize_enable_ppgtt(struct drm_device *dev, int enable_ppgtt)
if (enable_ppgtt == 2 && has_full_ppgtt)
return 2;

+ if (enable_ppgtt == 3 && has_full_48bit_ppgtt)
+ return 3;
+
#ifdef CONFIG_INTEL_IOMMU
/* Disable ppgtt on SNB if VT-d is on. */
if (INTEL_INFO(dev)->gen == 6 && intel_iommu_gfx_mapped) {
@@ -141,7 +146,7 @@ static int sanitize_enable_ppgtt(struct drm_device *dev, int enable_ppgtt)
}

if (INTEL_INFO(dev)->gen >= 8 && i915.enable_execlists)
- return 2;
+ return has_full_48bit_ppgtt ? 3 : 2;
else
return has_aliasing_ppgtt ? 1 : 0;
}
diff --git a/drivers/gpu/drm/i915/i915_params.c b/drivers/gpu/drm/i915/i915_params.c
index ca9b8f6..368df67 100644
--- a/drivers/gpu/drm/i915/i915_params.c
+++ b/drivers/gpu/drm/i915/i915_params.c
@@ -111,7 +111,7 @@ MODULE_PARM_DESC(enable_hangcheck,
module_param_named_unsafe(enable_ppgtt, i915.enable_ppgtt, int, 0400);
MODULE_PARM_DESC(enable_ppgtt,
"Override PPGTT usage. "
- "(-1=auto [default], 0=disabled, 1=aliasing, 2=full)");
+ "(-1=auto [default], 0=disabled, 1=aliasing, 2=full, 3=full with extended address space)");

module_param_named_unsafe(enable_execlists, i915.enable_execlists, int, 0400);
MODULE_PARM_DESC(enable_execlists,
--
2.6.0