From eaba1b8f3379b5d100bd146b9a41d28348bdfd09 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Thu, 4 Jul 2013 12:28:35 +0100 Subject: [PATCH] drm/i915: Verify that our stolen memory doesn't conflict Sanity check that the memory region found through the Graphics Base of Stolen Memory is reserved and hidden from the rest of the system through the use of the resource API. v2: "Graphics Stolen Memory" is such a more bodacious name than the lame "i915 stolen", and convert to using devres for automagical cleanup of the resource. (danvet) Signed-off-by: Chris Wilson Cc: Daniel Vetter [danvet: Dump proper hexcodes.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_gem_stolen.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index 08dd923c87d8..a3ce2cbb9221 100644 --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -46,6 +46,7 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev) { struct drm_i915_private *dev_priv = dev->dev_private; struct pci_dev *pdev = dev_priv->bridge_dev; + struct resource *r; u32 base; /* On the machines I have tested the Graphics Base of Stolen Memory @@ -88,6 +89,22 @@ static unsigned long i915_stolen_to_physical(struct drm_device *dev) #endif } + if (base == 0) + return 0; + + /* 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 + * is seriously wrong. + */ + r = devm_request_mem_region(dev->dev, base, dev_priv->gtt.stolen_size, + "Graphics Stolen Memory"); + if (r == NULL) { + DRM_ERROR("conflict detected with stolen region: [0x%08x - 0x%08x]\n", + base, base + (uint32_t)dev_priv->gtt.stolen_size); + base = 0; + } + return base; } -- 2.20.1