[PATCH 5/9] drm/i915: make dsm struct resource centric

Matthew Auld matthew.auld at intel.com
Tue Dec 5 14:44:58 UTC 2017


Now that we are using struct resource to track the stolen region, it is
more convenient if we track dsm in a resource as well.

v2: check range_overflow when writing to 32b registers (Chris)
    pepper in some comments (Chris)
v3: refit i915_stolen_to_dma()

Signed-off-by: Matthew Auld <matthew.auld at intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
---
 drivers/gpu/drm/i915/i915_drv.h        | 13 ++++--
 drivers/gpu/drm/i915/i915_gem_stolen.c | 84 +++++++++++++++++-----------------
 drivers/gpu/drm/i915/intel_fbc.c       | 10 +++-
 drivers/gpu/drm/i915/intel_pm.c        | 17 +++++--
 4 files changed, 72 insertions(+), 52 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 594fd14e66c5..39c8e99f3d3a 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1537,9 +1537,6 @@ struct i915_gem_mm {
 	 */
 	struct pagevec wc_stash;
 
-	/** Usable portion of the GTT for GEM */
-	dma_addr_t stolen_base; /* limited to low memory (32-bit) */
-
 	/**
 	 * tmpfs instance used for shmem backed objects
 	 */
@@ -2253,6 +2250,16 @@ struct drm_i915_private {
 
 	const struct intel_device_info info;
 
+	/**
+	 * Data Stolen Memory - aka "i915 stolen memory" gives us the start and
+	 * end of stolen which we can optionally use to create GEM objects
+	 * backed by stolen memory. Note that ggtt->stolen_usable_size tells us
+	 * exactly how much of this we are actually allowed to use, given that
+	 * some portion of it is in fact reserved for use by hardware functions,
+	 * while ggtt->stolen_size gives us the total size of the stolen region.
+	 */
+	struct resource dsm;
+
 	void __iomem *regs;
 
 	struct intel_uncore uncore;
diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c
index f8ac1438c35d..f07350c80ded 100644
--- a/drivers/gpu/drm/i915/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/i915_gem_stolen.c
@@ -76,27 +76,27 @@ void i915_gem_stolen_remove_node(struct drm_i915_private *dev_priv,
 	mutex_unlock(&dev_priv->mm.stolen_lock);
 }
 
-static dma_addr_t i915_stolen_to_dma(struct drm_i915_private *dev_priv)
+static int i915_adjust_stolen(struct drm_i915_private *dev_priv,
+			      struct resource *dsm)
 {
 	struct i915_ggtt *ggtt = &dev_priv->ggtt;
-	dma_addr_t base = intel_graphics_stolen_res.start;
+	dma_addr_t base = dsm->start;
 	struct resource *r;
 
 	GEM_BUG_ON(overflows_type(intel_graphics_stolen_res.start, base));
 
 	if (base == 0 || add_overflows(base, ggtt->stolen_size))
-		return 0;
+		return -EINVAL;
 
 	/* make sure we don't clobber the GTT if it's within stolen memory */
 	if (INTEL_GEN(dev_priv) <= 4 &&
 	    !IS_G33(dev_priv) && !IS_PINEVIEW(dev_priv) && !IS_G4X(dev_priv)) {
-		struct {
-			dma_addr_t start, end;
-		} stolen[2] = {
-			{ .start = base, .end = base + ggtt->stolen_size, },
-			{ .start = base, .end = base + ggtt->stolen_size, },
+		struct resource stolen[2] = {
+			DEFINE_RES_MEM(base, ggtt->stolen_size),
+			DEFINE_RES_MEM(base, ggtt->stolen_size),
 		};
-		u64 ggtt_start, ggtt_end;
+		struct resource ggtt_res;
+		u64 ggtt_start;
 
 		ggtt_start = I915_READ(PGTBL_CTL);
 		if (IS_GEN4(dev_priv))
@@ -104,36 +104,31 @@ static dma_addr_t i915_stolen_to_dma(struct drm_i915_private *dev_priv)
 				     (ggtt_start & PGTBL_ADDRESS_HI_MASK) << 28;
 		else
 			ggtt_start &= PGTBL_ADDRESS_LO_MASK;
-		ggtt_end = ggtt_start + ggtt_total_entries(ggtt) * 4;
 
-		if (ggtt_start >= stolen[0].start && ggtt_start < stolen[0].end)
-			stolen[0].end = ggtt_start;
-		if (ggtt_end > stolen[1].start && ggtt_end <= stolen[1].end)
-			stolen[1].start = ggtt_end;
+		ggtt_res =
+			(struct resource) DEFINE_RES_MEM(ggtt_start,
+							 ggtt_total_entries(ggtt) * 4);
+
+		if (ggtt_res.start >= stolen[0].start && ggtt_res.start < stolen[0].end)
+			stolen[0].end = ggtt_res.start;
+		if (ggtt_res.end > stolen[1].start && ggtt_res.end <= stolen[1].end)
+			stolen[1].start = ggtt_res.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;
-			ggtt->stolen_size = stolen[0].end - stolen[0].start;
-		} else {
-			base = stolen[1].start;
-			ggtt->stolen_size = stolen[1].end - stolen[1].start;
-		}
+		if (resource_size(&stolen[0]) > resource_size(&stolen[1]))
+			*dsm = stolen[0];
+		else
+			*dsm = stolen[1];
+
+		ggtt->stolen_size = resource_size(dsm);
 
 		if (stolen[0].start != stolen[1].start ||
 		    stolen[0].end != stolen[1].end) {
-			dma_addr_t end = base + ggtt->stolen_size - 1;
-
-			DRM_DEBUG_KMS("GTT within stolen memory at 0x%llx-0x%llx\n",
-				      (unsigned long long)ggtt_start,
-				      (unsigned long long)ggtt_end - 1);
-			DRM_DEBUG_KMS("Stolen memory adjusted to %pad - %pad\n",
-				      &base, &end);
+			DRM_DEBUG_KMS("GTT within stolen memory at %pR\n", &ggtt_res);
+			DRM_DEBUG_KMS("Stolen memory adjusted to %pR\n", &dsm);
 		}
 	}
 
-
 	/* 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
@@ -159,15 +154,14 @@ static dma_addr_t i915_stolen_to_dma(struct drm_i915_private *dev_priv)
 		 * range. Apparently this works.
 		 */
 		if (r == NULL && !IS_GEN3(dev_priv)) {
-			dma_addr_t end = base + ggtt->stolen_size;
+			DRM_ERROR("conflict detected with stolen region: %pR\n",
+				  &dsm);
 
-			DRM_ERROR("conflict detected with stolen region: [%pad - %pad]\n",
-				  &base, &end);
-			base = 0;
+			return -EBUSY;
 		}
 	}
 
-	return base;
+	return 0;
 }
 
 void i915_gem_cleanup_stolen(struct drm_device *dev)
@@ -187,7 +181,7 @@ static void g4x_get_stolen_reserved(struct drm_i915_private *dev_priv,
 	uint32_t reg_val = I915_READ(IS_GM45(dev_priv) ?
 				     CTG_STOLEN_RESERVED :
 				     ELK_STOLEN_RESERVED);
-	dma_addr_t stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size;
+	dma_addr_t stolen_top = dev_priv->dsm.start + ggtt->stolen_size;
 
 	if ((reg_val & G4X_STOLEN_RESERVED_ENABLE) == 0) {
 		*base = 0;
@@ -318,7 +312,7 @@ static void bdw_get_stolen_reserved(struct drm_i915_private *dev_priv,
 		return;
 	}
 
-	stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size;
+	stolen_top = dev_priv->dsm.start + ggtt->stolen_size;
 
 	*base = reg_val & GEN6_STOLEN_RESERVED_ADDR_MASK;
 
@@ -354,11 +348,15 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv)
 	if (ggtt->stolen_size == 0)
 		return 0;
 
-	dev_priv->mm.stolen_base = i915_stolen_to_dma(dev_priv);
-	if (dev_priv->mm.stolen_base == 0)
+	dev_priv->dsm = intel_graphics_stolen_res;
+
+	if (i915_adjust_stolen(dev_priv, &dev_priv->dsm))
 		return 0;
 
-	stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size;
+	GEM_BUG_ON(dev_priv->dsm.start == 0);
+	GEM_BUG_ON(ggtt->stolen_size > resource_size(&dev_priv->dsm));
+
+	stolen_top = dev_priv->dsm.end + 1;
 	reserved_base = 0;
 	reserved_size = 0;
 
@@ -399,12 +397,12 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv)
 		reserved_base = stolen_top;
 	}
 
-	if (reserved_base < dev_priv->mm.stolen_base ||
+	if (reserved_base < dev_priv->dsm.start ||
 	    reserved_base + reserved_size > stolen_top) {
 		dma_addr_t reserved_top = reserved_base + reserved_size;
 		DRM_ERROR("Stolen reserved area [%pad - %pad] outside stolen memory [%pad - %pad]\n",
 			  &reserved_base, &reserved_top,
-			  &dev_priv->mm.stolen_base, &stolen_top);
+			  &dev_priv->dsm.start, &stolen_top);
 		return 0;
 	}
 
@@ -462,7 +460,7 @@ i915_pages_create_for_stolen(struct drm_device *dev,
 	sg->offset = 0;
 	sg->length = size;
 
-	sg_dma_address(sg) = (dma_addr_t)dev_priv->mm.stolen_base + offset;
+	sg_dma_address(sg) = (dma_addr_t)dev_priv->dsm.start + offset;
 	sg_dma_len(sg) = size;
 
 	return st;
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index 4aefc658a5cf..a291bb965e2e 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -615,10 +615,16 @@ static int intel_fbc_alloc_cfb(struct intel_crtc *crtc)
 
 		fbc->compressed_llb = compressed_llb;
 
+		GEM_BUG_ON(range_overflows_t(u64, dev_priv->dsm.start,
+					     fbc->compressed_fb.start,
+					     U32_MAX));
+		GEM_BUG_ON(range_overflows_t(u64, dev_priv->dsm.start,
+					     fbc->compressed_llb->start,
+					     U32_MAX));
 		I915_WRITE(FBC_CFB_BASE,
-			   dev_priv->mm.stolen_base + fbc->compressed_fb.start);
+			   dev_priv->dsm.start + fbc->compressed_fb.start);
 		I915_WRITE(FBC_LL_BASE,
-			   dev_priv->mm.stolen_base + compressed_llb->start);
+			   dev_priv->dsm.start + compressed_llb->start);
 	}
 
 	DRM_DEBUG_KMS("reserved %llu bytes of contiguous stolen space for FBC, threshold: %d\n",
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 67f326230a7e..2fa2d82f61f2 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -7020,7 +7020,7 @@ static void valleyview_check_pctx(struct drm_i915_private *dev_priv)
 {
 	unsigned long pctx_addr = I915_READ(VLV_PCBR) & ~4095;
 
-	WARN_ON(pctx_addr != dev_priv->mm.stolen_base +
+	WARN_ON(pctx_addr != dev_priv->dsm.start +
 			     dev_priv->vlv_pctx->stolen->start);
 }
 
@@ -7043,7 +7043,12 @@ static void cherryview_setup_pctx(struct drm_i915_private *dev_priv)
 	pcbr = I915_READ(VLV_PCBR);
 	if ((pcbr >> VLV_PCBR_ADDR_SHIFT) == 0) {
 		DRM_DEBUG_DRIVER("BIOS didn't set up PCBR, fixing up\n");
-		paddr = (dev_priv->mm.stolen_base +
+
+		GEM_BUG_ON(range_overflows_t(resource_size_t,
+					     dev_priv->dsm.start,
+					     (ggtt->stolen_size - pctx_size),
+					     U32_MAX));
+		paddr = (dev_priv->dsm.start +
 			 (ggtt->stolen_size - pctx_size));
 
 		pctx_paddr = (paddr & (~4095));
@@ -7065,7 +7070,7 @@ static void valleyview_setup_pctx(struct drm_i915_private *dev_priv)
 		/* BIOS set it up already, grab the pre-alloc'd space */
 		int pcbr_offset;
 
-		pcbr_offset = (pcbr & (~4095)) - dev_priv->mm.stolen_base;
+		pcbr_offset = (pcbr & (~4095)) - dev_priv->dsm.start;
 		pctx = i915_gem_object_create_stolen_for_preallocated(dev_priv,
 								      pcbr_offset,
 								      I915_GTT_OFFSET_NONE,
@@ -7089,7 +7094,11 @@ static void valleyview_setup_pctx(struct drm_i915_private *dev_priv)
 		goto out;
 	}
 
-	pctx_paddr = dev_priv->mm.stolen_base + pctx->stolen->start;
+	GEM_BUG_ON(range_overflows_t(u64,
+				     dev_priv->dsm.start,
+				     pctx->stolen->start,
+				     U32_MAX));
+	pctx_paddr = dev_priv->dsm.start + pctx->stolen->start;
 	I915_WRITE(VLV_PCBR, pctx_paddr);
 
 out:
-- 
2.14.3



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