On Tue, Sep 14, 2021 at 10:05:03PM +0200, Daniel Vetter wrote:
On Tue, Sep 14, 2021 at 08:36:56AM -0700, Matthew Brost wrote:
On Tue, Sep 14, 2021 at 03:04:59PM +1000, Dave Airlie wrote:
On Tue, 14 Sept 2021 at 14:55, Matthew Brost matthew.brost@intel.com wrote:
From: Venkata Sandeep Dhanalakota venkata.s.dhanalakota@intel.com
Defining vma on stack can cause stack overflow, if vma gets populated with new fields.
Is there some higher level locking stopping that from getting trashed? or a guarantee that uc_fw_bind_ggtt is only entered by one thread at a time?
I believe this function is only called during driver load (inherently one thread) or during a GT reset (protected by reset mutex) so at most 1 thread can be executing this code at once, thus it is safe to use a global dummy vma in this function.
This kind of stuff must be documented in kerneldoc comments. Please use the inline struct member format.
Forgot to include kerneldoc for this new field, will add.
Also please document the other fields in that struct, cant hurt :-)
I'll see what I can do but I didn't write this code and may not fully understand all the fields off hand.
Matt
-Daniel
Matt
Dave.
Cc: Daniele Ceraolo Spurio daniele.ceraolospurio@intel.com Cc: Tvrtko Ursulin tvrtko.ursulin@intel.com Signed-off-by: Venkata Sandeep Dhanalakota venkata.s.dhanalakota@intel.com Signed-off-by: Matthew Brost matthew.brost@intel.com Reviewed-by: Matthew Brost matthew.brost@intel.com
drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c | 18 +++++++++--------- drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h | 2 ++ 2 files changed, 11 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c index 3a16d08608a5..f632dbd32b42 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.c @@ -413,20 +413,20 @@ static void uc_fw_bind_ggtt(struct intel_uc_fw *uc_fw) { struct drm_i915_gem_object *obj = uc_fw->obj; struct i915_ggtt *ggtt = __uc_fw_to_gt(uc_fw)->ggtt;
struct i915_vma dummy = {.node.start = uc_fw_ggtt_offset(uc_fw),.node.size = obj->base.size,.pages = obj->mm.pages,.vm = &ggtt->vm,};
struct i915_vma *dummy = &uc_fw->dummy;dummy->node.start = uc_fw_ggtt_offset(uc_fw);dummy->node.size = obj->base.size;dummy->pages = obj->mm.pages;dummy->vm = &ggtt->vm; GEM_BUG_ON(!i915_gem_object_has_pinned_pages(obj));
GEM_BUG_ON(dummy.node.size > ggtt->uc_fw.size);
GEM_BUG_ON(dummy->node.size > ggtt->uc_fw.size); /* uc_fw->obj cache domains were not controlled across suspend */
drm_clflush_sg(dummy.pages);
drm_clflush_sg(dummy->pages);
ggtt->vm.insert_entries(&ggtt->vm, &dummy, I915_CACHE_NONE, 0);
ggtt->vm.insert_entries(&ggtt->vm, dummy, I915_CACHE_NONE, 0);}
static void uc_fw_unbind_ggtt(struct intel_uc_fw *uc_fw) diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h index 99bb1fe1af66..693cc0ebcd63 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc_fw.h @@ -10,6 +10,7 @@ #include "intel_uc_fw_abi.h" #include "intel_device_info.h" #include "i915_gem.h" +#include "i915_vma.h"
struct drm_printer; struct drm_i915_private; @@ -75,6 +76,7 @@ struct intel_uc_fw { bool user_overridden; size_t size; struct drm_i915_gem_object *obj;
struct i915_vma dummy; /* * The firmware build process will generate a version header file with major and-- 2.32.0
-- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch