[Intel-gfx] [PATCH 11/19] drm/i915: Update the helper to set correct mapping
Matthew Auld
matthew.auld at intel.com
Mon Apr 19 14:37:46 UTC 2021
On 19/04/2021 15:07, Tvrtko Ursulin wrote:
>
> On 19/04/2021 12:30, Matthew Auld wrote:
>> On 15/04/2021 12:05, Tvrtko Ursulin wrote:
>>>
>>> On 15/04/2021 10:23, Matthew Auld wrote:
>>>> On Thu, 15 Apr 2021 at 09:21, Tvrtko Ursulin
>>>> <tvrtko.ursulin at linux.intel.com> wrote:
>>>>>
>>>>>
>>>>> On 14/04/2021 17:20, Matthew Auld wrote:
>>>>>> On Wed, 14 Apr 2021 at 16:22, Tvrtko Ursulin
>>>>>> <tvrtko.ursulin at linux.intel.com> wrote:
>>>>>>>
>>>>>>>
>>>>>>> On 12/04/2021 10:05, Matthew Auld wrote:
>>>>>>>> From: Venkata Sandeep Dhanalakota <venkata.s.dhanalakota at intel.com>
>>>>>>>>
>>>>>>>> Determine the possible coherent map type based on object location,
>>>>>>>> and if target has llc or if user requires an always coherent
>>>>>>>> mapping.
>>>>>>>>
>>>>>>>> Cc: Matthew Auld <matthew.auld at intel.com>
>>>>>>>> Cc: CQ Tang <cq.tang at intel.com>
>>>>>>>> Suggested-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
>>>>>>>> Signed-off-by: Venkata Sandeep Dhanalakota
>>>>>>>> <venkata.s.dhanalakota at intel.com>
>>>>>>>> ---
>>>>>>>> drivers/gpu/drm/i915/gt/intel_engine_cs.c | 3 ++-
>>>>>>>> drivers/gpu/drm/i915/gt/intel_engine_pm.c | 2 +-
>>>>>>>> drivers/gpu/drm/i915/gt/intel_lrc.c | 4 +++-
>>>>>>>> drivers/gpu/drm/i915/gt/intel_ring.c | 9 ++++++---
>>>>>>>> drivers/gpu/drm/i915/gt/selftest_context.c | 3 ++-
>>>>>>>> drivers/gpu/drm/i915/gt/selftest_hangcheck.c | 4 ++--
>>>>>>>> drivers/gpu/drm/i915/gt/selftest_lrc.c | 4 +++-
>>>>>>>> drivers/gpu/drm/i915/gt/uc/intel_guc.c | 4 +++-
>>>>>>>> drivers/gpu/drm/i915/gt/uc/intel_huc.c | 4 +++-
>>>>>>>> drivers/gpu/drm/i915/i915_drv.h | 11 +++++++++--
>>>>>>>> drivers/gpu/drm/i915/selftests/igt_spinner.c | 4 ++--
>>>>>>>> 11 files changed, 36 insertions(+), 16 deletions(-)
>>>>>>>>
>>>>>>>> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
>>>>>>>> b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
>>>>>>>> index efe935f80c1a..b79568d370f5 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
>>>>>>>> @@ -664,7 +664,8 @@ static int init_status_page(struct
>>>>>>>> intel_engine_cs *engine)
>>>>>>>> if (ret)
>>>>>>>> goto err;
>>>>>>>>
>>>>>>>> - vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
>>>>>>>> + vaddr = i915_gem_object_pin_map(obj,
>>>>>>>> + i915_coherent_map_type(engine->i915, obj, true));
>>>>>>>> if (IS_ERR(vaddr)) {
>>>>>>>> ret = PTR_ERR(vaddr);
>>>>>>>> goto err_unpin;
>>>>>>>> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
>>>>>>>> b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
>>>>>>>> index 7c9af86fdb1e..47f4397095e5 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/gt/intel_engine_pm.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/gt/intel_engine_pm.c
>>>>>>>> @@ -23,7 +23,7 @@ static void dbg_poison_ce(struct intel_context
>>>>>>>> *ce)
>>>>>>>>
>>>>>>>> if (ce->state) {
>>>>>>>> struct drm_i915_gem_object *obj = ce->state->obj;
>>>>>>>> - int type = i915_coherent_map_type(ce->engine->i915);
>>>>>>>> + int type =
>>>>>>>> i915_coherent_map_type(ce->engine->i915, obj, true);
>>>>>>>> void *map;
>>>>>>>>
>>>>>>>> if (!i915_gem_object_trylock(obj))
>>>>>>>> diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c
>>>>>>>> b/drivers/gpu/drm/i915/gt/intel_lrc.c
>>>>>>>> index e86897cde984..aafe2a4df496 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/gt/intel_lrc.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
>>>>>>>> @@ -903,7 +903,9 @@ lrc_pre_pin(struct intel_context *ce,
>>>>>>>> GEM_BUG_ON(!i915_vma_is_pinned(ce->state));
>>>>>>>>
>>>>>>>> *vaddr = i915_gem_object_pin_map(ce->state->obj,
>>>>>>>> - i915_coherent_map_type(ce->engine->i915) |
>>>>>>>> + i915_coherent_map_type(ce->engine->i915,
>>>>>>>> + ce->state->obj,
>>>>>>>> + false) |
>>>>>>>> I915_MAP_OVERRIDE);
>>>>>>>>
>>>>>>>> return PTR_ERR_OR_ZERO(*vaddr);
>>>>>>>> diff --git a/drivers/gpu/drm/i915/gt/intel_ring.c
>>>>>>>> b/drivers/gpu/drm/i915/gt/intel_ring.c
>>>>>>>> index aee0a77c77e0..3cf6c7e68108 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/gt/intel_ring.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/gt/intel_ring.c
>>>>>>>> @@ -53,9 +53,12 @@ int intel_ring_pin(struct intel_ring *ring,
>>>>>>>> struct i915_gem_ww_ctx *ww)
>>>>>>>>
>>>>>>>> if (i915_vma_is_map_and_fenceable(vma))
>>>>>>>> addr = (void __force *)i915_vma_pin_iomap(vma);
>>>>>>>> - else
>>>>>>>> - addr = i915_gem_object_pin_map(vma->obj,
>>>>>>>> - i915_coherent_map_type(vma->vm->i915));
>>>>>>>> + else {
>>>>>>>> + int type = i915_coherent_map_type(vma->vm->i915,
>>>>>>>> vma->obj, false);
>>>>>>>> +
>>>>>>>> + addr = i915_gem_object_pin_map(vma->obj, type);
>>>>>>>> + }
>>>>>>>> +
>>>>>>>> if (IS_ERR(addr)) {
>>>>>>>> ret = PTR_ERR(addr);
>>>>>>>> goto err_ring;
>>>>>>>> diff --git a/drivers/gpu/drm/i915/gt/selftest_context.c
>>>>>>>> b/drivers/gpu/drm/i915/gt/selftest_context.c
>>>>>>>> index b9bdd1d23243..26685b927169 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/gt/selftest_context.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/gt/selftest_context.c
>>>>>>>> @@ -88,7 +88,8 @@ static int __live_context_size(struct
>>>>>>>> intel_engine_cs *engine)
>>>>>>>> goto err;
>>>>>>>>
>>>>>>>> vaddr = i915_gem_object_pin_map_unlocked(ce->state->obj,
>>>>>>>> - i915_coherent_map_type(engine->i915));
>>>>>>>> + i915_coherent_map_type(engine->i915,
>>>>>>>> + ce->state->obj, false));
>>>>>>>> if (IS_ERR(vaddr)) {
>>>>>>>> err = PTR_ERR(vaddr);
>>>>>>>> intel_context_unpin(ce);
>>>>>>>> diff --git a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
>>>>>>>> b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
>>>>>>>> index 746985971c3a..5b63d4df8c93 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/gt/selftest_hangcheck.c
>>>>>>>> @@ -69,7 +69,7 @@ static int hang_init(struct hang *h, struct
>>>>>>>> intel_gt *gt)
>>>>>>>> h->seqno = memset(vaddr, 0xff, PAGE_SIZE);
>>>>>>>>
>>>>>>>> vaddr = i915_gem_object_pin_map_unlocked(h->obj,
>>>>>>>> - i915_coherent_map_type(gt->i915));
>>>>>>>> + i915_coherent_map_type(gt->i915, h->obj, false));
>>>>>>>> if (IS_ERR(vaddr)) {
>>>>>>>> err = PTR_ERR(vaddr);
>>>>>>>> goto err_unpin_hws;
>>>>>>>> @@ -130,7 +130,7 @@ hang_create_request(struct hang *h, struct
>>>>>>>> intel_engine_cs *engine)
>>>>>>>> return ERR_CAST(obj);
>>>>>>>> }
>>>>>>>>
>>>>>>>> - vaddr = i915_gem_object_pin_map_unlocked(obj,
>>>>>>>> i915_coherent_map_type(gt->i915));
>>>>>>>> + vaddr = i915_gem_object_pin_map_unlocked(obj,
>>>>>>>> i915_coherent_map_type(gt->i915, obj, false));
>>>>>>>> if (IS_ERR(vaddr)) {
>>>>>>>> i915_gem_object_put(obj);
>>>>>>>> i915_vm_put(vm);
>>>>>>>> diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c
>>>>>>>> b/drivers/gpu/drm/i915/gt/selftest_lrc.c
>>>>>>>> index 85e7df6a5123..d8f6623524e8 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
>>>>>>>> @@ -1221,7 +1221,9 @@ static int compare_isolation(struct
>>>>>>>> intel_engine_cs *engine,
>>>>>>>> }
>>>>>>>>
>>>>>>>> lrc = i915_gem_object_pin_map_unlocked(ce->state->obj,
>>>>>>>> - i915_coherent_map_type(engine->i915));
>>>>>>>> + i915_coherent_map_type(engine->i915,
>>>>>>>> + ce->state->obj,
>>>>>>>> + false));
>>>>>>>> if (IS_ERR(lrc)) {
>>>>>>>> err = PTR_ERR(lrc);
>>>>>>>> goto err_B1;
>>>>>>>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.c
>>>>>>>> b/drivers/gpu/drm/i915/gt/uc/intel_guc.c
>>>>>>>> index 78305b2ec89d..adae04c47aab 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.c
>>>>>>>> @@ -682,7 +682,9 @@ int intel_guc_allocate_and_map_vma(struct
>>>>>>>> intel_guc *guc, u32 size,
>>>>>>>> if (IS_ERR(vma))
>>>>>>>> return PTR_ERR(vma);
>>>>>>>>
>>>>>>>> - vaddr = i915_gem_object_pin_map_unlocked(vma->obj,
>>>>>>>> I915_MAP_WB);
>>>>>>>> + vaddr = i915_gem_object_pin_map_unlocked(vma->obj,
>>>>>>>> + i915_coherent_map_type(guc_to_gt(guc)->i915,
>>>>>>>> + vma->obj, true));
>>>>>>>> if (IS_ERR(vaddr)) {
>>>>>>>> i915_vma_unpin_and_release(&vma, 0);
>>>>>>>> return PTR_ERR(vaddr);
>>>>>>>> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_huc.c
>>>>>>>> b/drivers/gpu/drm/i915/gt/uc/intel_huc.c
>>>>>>>> index 2126dd81ac38..56d2144dc6a0 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/gt/uc/intel_huc.c
>>>>>>>> +++ b/drivers/gpu/drm/i915/gt/uc/intel_huc.c
>>>>>>>> @@ -82,7 +82,9 @@ static int intel_huc_rsa_data_create(struct
>>>>>>>> intel_huc *huc)
>>>>>>>> if (IS_ERR(vma))
>>>>>>>> return PTR_ERR(vma);
>>>>>>>>
>>>>>>>> - vaddr = i915_gem_object_pin_map_unlocked(vma->obj,
>>>>>>>> I915_MAP_WB);
>>>>>>>> + vaddr = i915_gem_object_pin_map_unlocked(vma->obj,
>>>>>>>> + i915_coherent_map_type(gt->i915,
>>>>>>>> + vma->obj, true));
>>>>>>>> if (IS_ERR(vaddr)) {
>>>>>>>> i915_vma_unpin_and_release(&vma, 0);
>>>>>>>> return PTR_ERR(vaddr);
>>>>>>>> diff --git a/drivers/gpu/drm/i915/i915_drv.h
>>>>>>>> b/drivers/gpu/drm/i915/i915_drv.h
>>>>>>>> index 69e43bf91a15..2abbc06712a4 100644
>>>>>>>> --- a/drivers/gpu/drm/i915/i915_drv.h
>>>>>>>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>>>>>>>> @@ -78,6 +78,7 @@
>>>>>>>> #include "gem/i915_gem_context_types.h"
>>>>>>>> #include "gem/i915_gem_shrinker.h"
>>>>>>>> #include "gem/i915_gem_stolen.h"
>>>>>>>> +#include "gem/i915_gem_lmem.h"
>>>>>>>>
>>>>>>>> #include "gt/intel_engine.h"
>>>>>>>> #include "gt/intel_gt_types.h"
>>>>>>>> @@ -1921,9 +1922,15 @@ static inline int
>>>>>>>> intel_hws_csb_write_index(struct drm_i915_private *i915)
>>>>>>>> }
>>>>>>>>
>>>>>>>> static inline enum i915_map_type
>>>>>>>> -i915_coherent_map_type(struct drm_i915_private *i915)
>>>>>>>> +i915_coherent_map_type(struct drm_i915_private *i915,
>>>>>>>> + struct drm_i915_gem_object *obj, bool
>>>>>>>> always_coherent)
>>>>>>>> {
>>>>>>>> - return HAS_LLC(i915) ? I915_MAP_WB : I915_MAP_WC;
>>>>>>>> + if (i915_gem_object_is_lmem(obj))
>>>>>>>> + return I915_MAP_WC;
>>>>>>>> + if (HAS_LLC(i915) || always_coherent)
>>>>>>>> + return I915_MAP_WB;
>>>>>>>> + else
>>>>>>>> + return I915_MAP_WC;
>>>>>>>
>>>>>>> Seems this patch is doing two things.
>>>>>>>
>>>>>>> First it is adding lmem support to this helper by always
>>>>>>> returning WC
>>>>>>> for lmem objects.
>>>>>>>
>>>>>>> Secondly it is introducing an idea of "always coherent" in a helper
>>>>>>> called i915_coherent_map_type. Could someone explain what is
>>>>>>> coherent vs
>>>>>>> always coherent?
>>>>>>>
>>>>>>> And also, why is always coherent happy with WB? Sounds counter
>>>>>>> intuitive
>>>>>>> to me.
>>>>>>
>>>>>> All this does is try to keep the existing behaviour intact, whilst
>>>>>> also ensuring that all lmem objects are mapped using only WC, no
>>>>>> matter what. The always_coherent=true thing is for the existing
>>>>>> places
>>>>>> where we sometimes map the object using WB, without first considering
>>>>>> whether the device has the fast shared LLC vs snooping. Yes, it's
>>>>>> slightly ugly :)
>>>>>
>>>>> Not fully following - if we had to write kerneldoc for always_coherent
>>>>> input argument - what it would say?
>>>>
>>>> @always_coherent - If true we should always try to map the object
>>>> using WB. If false we should only map as WB if the device supports the
>>>> fast shared LLC, in the case of snooped devices we will map use WC.
>>>> Note that If the resource is lmem then we will always map as WC,
>>>> regardless of the value of always_coherent, since that's all we
>>>> currently support.
>>>>
>>>> Maybe the naming is poor?
>>>
>>> Maybe just confusing to me, not sure yet.
>>>
>>> So always_coherent is not about how the callers wants to use it, but
>>> about platform knowledge? Or a performance concern for LLC vs
>>> snooping cases? Does WB works (coherently) on snooping platforms?
>>
>> The always_coherent=true is for the existing callers that want WB,
>> regardless of LLC vs snooping.
>>
>> The other callers use the existing i915_coherent_map_type() which only
>> gives out WB for LLC platforms.
>>
>> AFAIK, LLC vs snooping should offer the same in terms of coherency,
>> but in terms of performance the shared LLC is much faster, and so for
>> snooping platforms we choose to not enable WB everywhere.
>>
>> On top of that we now have lmem, but for that we only allow WC. This
>> patch just rolls all of that into one helper, while keeping the
>> existing behaviour unchanged.
>
> Thanks. But I am still struggling with the API. :(
>
> Is the introduction of always_coherent flag in the context of DG1
> required even? AFAICT for lmem objects the flag is ignored so no?
If we drop the flag/helper thing, then we need something like:
type = WB;
if (i915_gem_object_is_lmem(obj))
type = WC;
vaddr = i915_gem_object_pin_map(obj, type);
In all the places where we currently do:
vaddr = i915_gem_object_pin_map(obj, WB);
Where obj can be lmem, so ctx, ring, guc etc. Is that better or worse?
The existing i915_coherent_map_type() callers should work as-is, since
DG1 is snooped. And this patch just extends that to cover all cases.
Perhaps we need a new helper instead? Maybe you have a better idea?
>
> Regards,
>
> Tvrtko
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