From c88473878d47131ccfc67a00ba688d4d7d0f4519 Mon Sep 17 00:00:00 2001 From: Chris Wilson Date: Fri, 27 Jan 2017 16:55:30 +0000 Subject: [PATCH] drm/i915: Treat stolen memory as DMA addresses MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The conversion of stolen to use phys_addr_t (from essentially u32) sparked an interesting discussion. We treat stolen memory as only accessible from the GPU (the DMA device) - an attempt to use it from the CPU will generate a MCE on gen6 onwards, although it is in theory a physical address that can be dereferenced from the CPU as demonstrated by earlier generations. As such, using phys_addr_t has the wrong connotations and as we pass the address into the DMA device via dma_addr_t (through the scatterlists used to program the GTT entries), we should treat it as dma_addr_t throughout. Signed-off-by: Chris Wilson Cc: Paulo Zanoni Cc: Ville Syrjälä Link: http://patchwork.freedesktop.org/patch/msgid/20170127165531.28135-1-chris@chris-wilson.co.uk Reviewed-by: Paulo Zanoni --- drivers/gpu/drm/i915/i915_drv.h | 2 +- drivers/gpu/drm/i915/i915_gem_stolen.c | 36 +++++++++++++------------- 2 files changed, 19 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 448e5d85d1e0..15f0fc48c442 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -1461,7 +1461,7 @@ struct i915_gem_mm { struct work_struct free_work; /** Usable portion of the GTT for GEM */ - phys_addr_t stolen_base; /* limited to low memory (32-bit) */ + dma_addr_t stolen_base; /* limited to low memory (32-bit) */ /** PPGTT used for aliasing the PPGTT with the GTT */ struct i915_hw_ppgtt *aliasing_ppgtt; diff --git a/drivers/gpu/drm/i915/i915_gem_stolen.c b/drivers/gpu/drm/i915/i915_gem_stolen.c index 729dba017b78..a75de8c6ece0 100644 --- a/drivers/gpu/drm/i915/i915_gem_stolen.c +++ b/drivers/gpu/drm/i915/i915_gem_stolen.c @@ -79,12 +79,12 @@ void i915_gem_stolen_remove_node(struct drm_i915_private *dev_priv, mutex_unlock(&dev_priv->mm.stolen_lock); } -static phys_addr_t i915_stolen_to_physical(struct drm_i915_private *dev_priv) +static dma_addr_t i915_stolen_to_dma(struct drm_i915_private *dev_priv) { struct pci_dev *pdev = dev_priv->drm.pdev; struct i915_ggtt *ggtt = &dev_priv->ggtt; struct resource *r; - phys_addr_t base; + dma_addr_t base; /* Almost universally we can find the Graphics Base of Stolen Memory * at register BSM (0x5c) in the igfx configuration space. On a few @@ -196,7 +196,7 @@ static phys_addr_t i915_stolen_to_physical(struct drm_i915_private *dev_priv) if (INTEL_GEN(dev_priv) <= 4 && !IS_G33(dev_priv) && !IS_PINEVIEW(dev_priv) && !IS_G4X(dev_priv)) { struct { - phys_addr_t start, end; + dma_addr_t start, end; } stolen[2] = { { .start = base, .end = base + ggtt->stolen_size, }, { .start = base, .end = base + ggtt->stolen_size, }, @@ -228,12 +228,12 @@ static phys_addr_t i915_stolen_to_physical(struct drm_i915_private *dev_priv) if (stolen[0].start != stolen[1].start || stolen[0].end != stolen[1].end) { - phys_addr_t end = base + ggtt->stolen_size - 1; + 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 %pa - %pa\n", + DRM_DEBUG_KMS("Stolen memory adjusted to %pad - %pad\n", &base, &end); } } @@ -263,9 +263,9 @@ static phys_addr_t i915_stolen_to_physical(struct drm_i915_private *dev_priv) * range. Apparently this works. */ if (r == NULL && !IS_GEN3(dev_priv)) { - phys_addr_t end = base + ggtt->stolen_size; + dma_addr_t end = base + ggtt->stolen_size; - DRM_ERROR("conflict detected with stolen region: [%pa - %pa]\n", + DRM_ERROR("conflict detected with stolen region: [%pad - %pad]\n", &base, &end); base = 0; } @@ -285,13 +285,13 @@ void i915_gem_cleanup_stolen(struct drm_device *dev) } static void g4x_get_stolen_reserved(struct drm_i915_private *dev_priv, - phys_addr_t *base, u32 *size) + dma_addr_t *base, u32 *size) { struct i915_ggtt *ggtt = &dev_priv->ggtt; uint32_t reg_val = I915_READ(IS_GM45(dev_priv) ? CTG_STOLEN_RESERVED : ELK_STOLEN_RESERVED); - phys_addr_t stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size; + dma_addr_t stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size; *base = (reg_val & G4X_STOLEN_RESERVED_ADDR2_MASK) << 16; @@ -308,7 +308,7 @@ static void g4x_get_stolen_reserved(struct drm_i915_private *dev_priv, } static void gen6_get_stolen_reserved(struct drm_i915_private *dev_priv, - phys_addr_t *base, u32 *size) + dma_addr_t *base, u32 *size) { uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED); @@ -334,7 +334,7 @@ static void gen6_get_stolen_reserved(struct drm_i915_private *dev_priv, } static void gen7_get_stolen_reserved(struct drm_i915_private *dev_priv, - phys_addr_t *base, u32 *size) + dma_addr_t *base, u32 *size) { uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED); @@ -354,7 +354,7 @@ static void gen7_get_stolen_reserved(struct drm_i915_private *dev_priv, } static void chv_get_stolen_reserved(struct drm_i915_private *dev_priv, - phys_addr_t *base, u32 *size) + dma_addr_t *base, u32 *size) { uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED); @@ -380,11 +380,11 @@ static void chv_get_stolen_reserved(struct drm_i915_private *dev_priv, } static void bdw_get_stolen_reserved(struct drm_i915_private *dev_priv, - phys_addr_t *base, u32 *size) + dma_addr_t *base, u32 *size) { struct i915_ggtt *ggtt = &dev_priv->ggtt; uint32_t reg_val = I915_READ(GEN6_STOLEN_RESERVED); - phys_addr_t stolen_top; + dma_addr_t stolen_top; stolen_top = dev_priv->mm.stolen_base + ggtt->stolen_size; @@ -403,7 +403,7 @@ static void bdw_get_stolen_reserved(struct drm_i915_private *dev_priv, int i915_gem_init_stolen(struct drm_i915_private *dev_priv) { struct i915_ggtt *ggtt = &dev_priv->ggtt; - phys_addr_t reserved_base, stolen_top; + dma_addr_t reserved_base, stolen_top; u32 reserved_total, reserved_size; u32 stolen_usable_start; @@ -419,7 +419,7 @@ 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_physical(dev_priv); + dev_priv->mm.stolen_base = i915_stolen_to_dma(dev_priv); if (dev_priv->mm.stolen_base == 0) return 0; @@ -468,8 +468,8 @@ int i915_gem_init_stolen(struct drm_i915_private *dev_priv) if (reserved_base < dev_priv->mm.stolen_base || reserved_base + reserved_size > stolen_top) { - phys_addr_t reserved_top = reserved_base + reserved_size; - DRM_DEBUG_KMS("Stolen reserved area [%pa - %pa] outside stolen memory [%pa - %pa]\n", + dma_addr_t reserved_top = reserved_base + reserved_size; + DRM_DEBUG_KMS("Stolen reserved area [%pad - %pad] outside stolen memory [%pad - %pad]\n", &reserved_base, &reserved_top, &dev_priv->mm.stolen_base, &stolen_top); return 0; -- 2.30.2