[Intel-gfx] [PATCH 1/2] drm/i915: Treat stolen memory as DMA addresses
Chris Wilson
chris at chris-wilson.co.uk
Fri Jan 27 16:55:30 UTC 2017
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 <chris at chris-wilson.co.uk>
Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
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 d0a48cceb15b..a43ba7872d7c 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1467,7 +1467,7 @@ 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 7226e4a21097..42bbc4b04fd6 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;
@@ -424,7 +424,7 @@ 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;
@@ -473,8 +473,8 @@ 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;
--
2.11.0
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