At least on BXT A stepping we need to map part of the context object as uncached. For this we first set the corresponding page to uncached and then use kmap/kunmap to get a kernel mapping whenever we want to update the context. Since kmap for a HIGHMEM page always returns a write-back mapping we need to prevent allocating the context object from HIGHMEM.
Needed by the next patch implementing the actual workaround for BXT A. Signed-off-by: Imre Deak <[email protected]> --- drivers/gpu/drm/i915/i915_drv.h | 2 ++ drivers/gpu/drm/i915/i915_gem.c | 21 ++++++++++++++++++--- drivers/gpu/drm/i915/intel_lrc.c | 5 ++++- 3 files changed, 24 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index 4ea3e7b..6e7f91e 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2806,6 +2806,8 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj, const struct drm_i915_gem_object_ops *ops); struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev, size_t size); +struct drm_i915_gem_object * +i915_gem_alloc_object_no_highmem(struct drm_device *dev, size_t size); struct drm_i915_gem_object *i915_gem_object_create_from_data( struct drm_device *dev, const void *data, size_t size); void i915_init_vm(struct drm_i915_private *dev_priv, diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index cb0df7e..11c9191 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -4243,8 +4243,8 @@ static const struct drm_i915_gem_object_ops i915_gem_object_ops = { .put_pages = i915_gem_object_put_pages_gtt, }; -struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev, - size_t size) +static struct drm_i915_gem_object * +__i915_gem_alloc_object(struct drm_device *dev, size_t size, bool highmem) { struct drm_i915_gem_object *obj; struct address_space *mapping; @@ -4262,10 +4262,13 @@ struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev, mask = GFP_HIGHUSER | __GFP_RECLAIMABLE; if (IS_CRESTLINE(dev) || IS_BROADWATER(dev)) { /* 965gm cannot relocate objects above 4GiB. */ - mask &= ~__GFP_HIGHMEM; + highmem = false; mask |= __GFP_DMA32; } + if (!highmem) + mask &= ~__GFP_HIGHMEM; + mapping = file_inode(obj->base.filp)->i_mapping; mapping_set_gfp_mask(mapping, mask); @@ -4296,6 +4299,18 @@ struct drm_i915_gem_object *i915_gem_alloc_object(struct drm_device *dev, return obj; } +struct drm_i915_gem_object * +i915_gem_alloc_object(struct drm_device *dev, size_t size) +{ + return __i915_gem_alloc_object(dev, size, true); +} + +struct drm_i915_gem_object * +i915_gem_alloc_object_no_highmem(struct drm_device *dev, size_t size) +{ + return __i915_gem_alloc_object(dev, size, false); +} + static bool discard_backing_storage(struct drm_i915_gem_object *obj) { /* If we are the last user of the backing storage (be it shmemfs diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index fe06accb0..942069f 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -2459,7 +2459,10 @@ int intel_lr_context_deferred_alloc(struct intel_context *ctx, /* One extra page as the sharing data between driver and GuC */ context_size += PAGE_SIZE * LRC_PPHWSP_PN; - ctx_obj = i915_gem_alloc_object(dev, context_size); + if (IS_BROXTON(dev) && INTEL_REVID(dev) < BXT_REVID_B0) + ctx_obj = i915_gem_alloc_object_no_highmem(dev, context_size); + else + ctx_obj = i915_gem_alloc_object(dev, context_size); if (!ctx_obj) { DRM_DEBUG_DRIVER("Alloc LRC backing obj failed.\n"); return -ENOMEM; -- 2.1.4 _______________________________________________ Intel-gfx mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/intel-gfx
