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Commit f1e1c212 authored by Ville Syrjälä's avatar Ville Syrjälä Committed by Daniel Vetter
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drm/i915: Don't clobber the GTT when it's within stolen memory 



On most gen2-4 platforms the GTT can be (or maybe always is?)
inside the stolen memory region. If that's the case, reduce the
size of the stolen memory appropriately to make make sure we
don't clobber the GTT.

v2: Deal with gen4 36 bit physical address

Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=80151


Acked-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent aceb365c

drivers/gpu/drm/i915/i915_gem_stolen.c

+44 −0
Original line number Diff line number Diff line
@@ -74,6 +74,50 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev) 
	if (base == 0)

		return 0;



	/* make sure we don't clobber the GTT if it's within stolen memory */

	if (INTEL_INFO(dev)->gen <= 4 && !IS_G33(dev) && !IS_G4X(dev)) {

		struct {

			u32 start, end;

		} stolen[2] = {

			{ .start = base, .end = base + dev_priv->gtt.stolen_size, },

			{ .start = base, .end = base + dev_priv->gtt.stolen_size, },

		};

		u64 gtt_start, gtt_end;



		gtt_start = I915_READ(PGTBL_CTL);

		if (IS_GEN4(dev))

			gtt_start = (gtt_start & PGTBL_ADDRESS_LO_MASK) |

				(gtt_start & PGTBL_ADDRESS_HI_MASK) << 28;

		else

			gtt_start &= PGTBL_ADDRESS_LO_MASK;

		gtt_end = gtt_start + gtt_total_entries(dev_priv->gtt) * 4;



		if (gtt_start >= stolen[0].start && gtt_start < stolen[0].end)

			stolen[0].end = gtt_start;

		if (gtt_end > stolen[1].start && gtt_end <= stolen[1].end)

			stolen[1].start = gtt_end;



		/* pick the larger of the two chunks */

		if (stolen[0].end - stolen[0].start >

		    stolen[1].end - stolen[1].start) {

			base = stolen[0].start;

			dev_priv->gtt.stolen_size = stolen[0].end - stolen[0].start;

		} else {

			base = stolen[1].start;

			dev_priv->gtt.stolen_size = stolen[1].end - stolen[1].start;

		}



		if (stolen[0].start != stolen[1].start ||

		    stolen[0].end != stolen[1].end) {

			DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",

				      (unsigned long long) gtt_start,

				      (unsigned long long) gtt_end - 1);

			DRM_DEBUG_KMS("Stolen memory adjusted to 0x%x-0x%x\n",

				      base, base + (u32) dev_priv->gtt.stolen_size - 1);

		}

	}





	/* Verify that nothing else uses this physical address. Stolen

	 * memory should be reserved by the BIOS and hidden from the

	 * kernel. So if the region is already marked as busy, something

drivers/gpu/drm/i915/i915_reg.h

+3 −0
Original line number Diff line number Diff line
@@ -942,6 +942,9 @@ enum punit_power_well { 
/*

 * Instruction and interrupt control regs

 */

#define PGTBL_CTL	0x02020

#define   PGTBL_ADDRESS_LO_MASK	0xfffff000 /* bits [31:12] */

#define   PGTBL_ADDRESS_HI_MASK	0x000000f0 /* bits [35:32] (gen4) */

#define PGTBL_ER	0x02024

#define RENDER_RING_BASE	0x02000

#define BSD_RING_BASE		0x04000