[PATCH 1/2] xe/oa: Fix query mode of operation for OAR/OAC

Dixit, Ashutosh ashutosh.dixit at intel.com
Thu Dec 19 23:15:29 UTC 2024


On Wed, 18 Dec 2024 16:23:39 -0800, Umesh Nerlige Ramappa wrote:
>

Hi Umesh,

> This is a set of squashed commits to facilitate smooth applying to
> stable. Each commit message is retained for reference.
>
> 1) Allow a GGTT mapped batch to be submitted to user exec queue
>
> For a OA use case, one of the HW registers needs to be modified by
> submitting an MI_LOAD_REGISTER_IMM command to the users exec queue, so
> that the register is modified in the user's hardware context. In order
> to do this a batch that is mapped in GGTT, needs to be submitted to the
> user exec queue. Since all user submissions use q->vm and hence PPGTT,
> add some plumbing to enable submission of batches mapped in GGTT.
>
> v2: ggtt is zero-initialized, so no need to set it false (Matt Brost)
>
> 2) xe/oa: Use MI_LOAD_REGISTER_IMMEDIATE to enable OAR/OAC
>
> To enable OAR/OAC, a bit in RING_CONTEXT_CONTROL needs to be set.
> Setting this bit cause the context image size to change and if not done
> correct, can cause undesired hangs.
>
> Current code uses a separate exec_queue to modify this bit and is
> error-prone. As per HW recommendation, submit MI_LOAD_REGISTER_IMM to
> the target hardware context to modify the relevant bit.
>
> In v2 version, an attempt to submit everything to the user-queue was
> made, but it failed the unprivileged-single-ctx-counters test. It
> appears that the OACTXCONTROL must be modified from a remote context.
>
> In v3 version, all context specific register configurations were moved
> to use LOAD_REGISTER_IMMEDIATE and that seems to work well. This is a
> cleaner way, since we can now submit all configuration to user
> exec_queue and the fence handling is simplified.
>
> v2:
> (Matt)
> - set job->ggtt to true if create job is successful
> - unlock vm on job error
>
> (Ashutosh)
> - don't wait on job submission
> - use kernel exec queue where possible
>
> v3:
> (Ashutosh)
> - Fix checkpatch issues
> - Remove extra spaces/new-lines
> - Add Fixes: and Cc: tags
> - Reset context control bit when OA stream is closed
> - Submit all config via MI_LOAD_REGISTER_IMMEDIATE
>
> (Umesh)
> - Update commit message for v3 experiment
> - Squash patches for easier port to stable

Strictly not needed, all patches can just have a Fixes and Cc:stable and
they should get applied correctly. Anyway, I have no problems reviewing as
is.

But this series is a really nice cleanup :)

>
> Fixes: 8135f1c09dd2 ("drm/xe/oa: Don't reset OAC_CONTEXT_ENABLE on OA stream close")
> Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
> Reviewed-by: Matthew Brost <matthew.brost at intel.com> # commit 1
> Cc: stable at vger.kernel.org
> ---
>  drivers/gpu/drm/xe/xe_oa.c              | 137 ++++++++----------------
>  drivers/gpu/drm/xe/xe_ring_ops.c        |   5 +-
>  drivers/gpu/drm/xe/xe_sched_job_types.h |   2 +
>  3 files changed, 53 insertions(+), 91 deletions(-)
>
> diff --git a/drivers/gpu/drm/xe/xe_oa.c b/drivers/gpu/drm/xe/xe_oa.c
> index ae94490b0eac..86dd8fe0b6a5 100644
> --- a/drivers/gpu/drm/xe/xe_oa.c
> +++ b/drivers/gpu/drm/xe/xe_oa.c
> @@ -74,12 +74,6 @@ struct xe_oa_config {
>	struct rcu_head rcu;
>  };
>
> -struct flex {
> -	struct xe_reg reg;
> -	u32 offset;
> -	u32 value;
> -};
> -
>  struct xe_oa_open_param {
>	struct xe_file *xef;
>	u32 oa_unit_id;
> @@ -605,19 +599,39 @@ static __poll_t xe_oa_poll(struct file *file, poll_table *wait)
>	return ret;
>  }
>
> -static struct dma_fence *xe_oa_submit_bb(struct xe_oa_stream *stream, enum xe_oa_submit_deps deps,
> +static void xe_oa_lock_vma(struct xe_exec_queue *q)
> +{
> +	if (q->vm) {
> +		down_read(&q->vm->lock);
> +		xe_vm_lock(q->vm, false);
> +	}
> +}
> +
> +static void xe_oa_unlock_vma(struct xe_exec_queue *q)
> +{
> +	if (q->vm) {
> +		xe_vm_unlock(q->vm);
> +		up_read(&q->vm->lock);
> +	}
> +}
> +
> +static struct dma_fence *xe_oa_submit_bb(struct xe_oa_stream *stream,
> +					 struct xe_exec_queue *q,

The new q argument is now strictly not needed. We can just do:

	struct xe_exec_queue *q = stream->exec_q ?: stream->k_exec_q;

here, since all batches are sent to a single exec_q.

> +					 enum xe_oa_submit_deps deps,
>					 struct xe_bb *bb)
>  {
>	struct xe_sched_job *job;
>	struct dma_fence *fence;
>	int err = 0;
>
> -	/* Kernel configuration is issued on stream->k_exec_q, not stream->exec_q */
> -	job = xe_bb_create_job(stream->k_exec_q, bb);
> +	xe_oa_lock_vma(q);
> +
> +	job = xe_bb_create_job(q, bb);

There is a issue here, which is:

	struct xe_sched_job *xe_bb_create_job(struct xe_exec_queue *q,
					      struct xe_bb *bb)
	{
		...
		xe_gt_assert(q->gt, q->width == 1);

So xe_bb_create_job is used to create kernel jobs using kernel exec_q's,
all of which have width 1. This may not be true for user exec_q's.

The assert is needed because xe_bb_create_job() passes only a single
batch_addr to xe_sched_job_create(). If userspace passes in a queue with
width > 1, from xe_sched_job_create() it looks like bad things could happen
(not just the assert/warn).

So for this, I think we should do this:

@@ -1981,8 +1981,8 @@ int xe_oa_stream_open_ioctl(struct drm_device *dev, u64 data, struct drm_file *f
 		if (XE_IOCTL_DBG(oa->xe, !param.exec_q))
 			return -ENOENT;
 
-		if (param.exec_q->width > 1)
-			drm_dbg(&oa->xe->drm, "exec_q->width > 1, programming only exec_q->lrc[0]\n");
+		if (XE_IOCTL_DBG(oa->xe, param.exec_q->width > 1)
+			return -EOPNOTSUPP;

Basically earlier we were just doing a drm_dbg, but now let's just make
'q->width == 1' a hard requirement. We can revisit this if indeed we need
to support q->width > 1.

>	if (IS_ERR(job)) {
>		err = PTR_ERR(job);
>		goto exit;
>	}
> +	job->ggtt = true;
>
>	if (deps == XE_OA_SUBMIT_ADD_DEPS) {
>		for (int i = 0; i < stream->num_syncs && !err; i++)
> @@ -632,10 +646,13 @@ static struct dma_fence *xe_oa_submit_bb(struct xe_oa_stream *stream, enum xe_oa
>	fence = dma_fence_get(&job->drm.s_fence->finished);
>	xe_sched_job_push(job);
>
> +	xe_oa_unlock_vma(q);
> +
>	return fence;
>  err_put_job:
>	xe_sched_job_put(job);
>  exit:
> +	xe_oa_unlock_vma(q);
>	return ERR_PTR(err);
>  }
>
> @@ -684,67 +701,22 @@ static void xe_oa_free_configs(struct xe_oa_stream *stream)
>	dma_fence_put(stream->last_fence);
>  }
>
> -static void xe_oa_store_flex(struct xe_oa_stream *stream, struct xe_lrc *lrc,
> -			     struct xe_bb *bb, const struct flex *flex, u32 count)
> -{
> -	u32 offset = xe_bo_ggtt_addr(lrc->bo);
> -
> -	do {
> -		bb->cs[bb->len++] = MI_STORE_DATA_IMM | MI_SDI_GGTT |
> -				    MI_FORCE_WRITE_COMPLETION_CHECK |
> -				    MI_SDI_NUM_DW(1);
> -		bb->cs[bb->len++] = offset + flex->offset * sizeof(u32);
> -		bb->cs[bb->len++] = 0;
> -		bb->cs[bb->len++] = flex->value;
> -
> -	} while (flex++, --count);
> -}
> -
> -static int xe_oa_modify_ctx_image(struct xe_oa_stream *stream, struct xe_lrc *lrc,
> -				  const struct flex *flex, u32 count)
> -{
> -	struct dma_fence *fence;
> -	struct xe_bb *bb;
> -	int err;
> -
> -	bb = xe_bb_new(stream->gt, 4 * count, false);
> -	if (IS_ERR(bb)) {
> -		err = PTR_ERR(bb);
> -		goto exit;
> -	}
> -
> -	xe_oa_store_flex(stream, lrc, bb, flex, count);
> -
> -	fence = xe_oa_submit_bb(stream, XE_OA_SUBMIT_NO_DEPS, bb);
> -	if (IS_ERR(fence)) {
> -		err = PTR_ERR(fence);
> -		goto free_bb;
> -	}
> -	xe_bb_free(bb, fence);
> -	dma_fence_put(fence);
> -
> -	return 0;
> -free_bb:
> -	xe_bb_free(bb, NULL);
> -exit:
> -	return err;
> -}
> -
> -static int xe_oa_load_with_lri(struct xe_oa_stream *stream, struct xe_oa_reg *reg_lri)
> +static int xe_oa_load_with_lri(struct xe_oa_stream *stream, struct xe_oa_reg *reg_lri, u32 count)
>  {
> +	struct xe_exec_queue *q = stream->exec_q;
>	struct dma_fence *fence;
>	struct xe_bb *bb;
>	int err;
>
> -	bb = xe_bb_new(stream->gt, 3, false);
> +	bb = xe_bb_new(stream->gt, 2 * count + 1, false);
>	if (IS_ERR(bb)) {
>		err = PTR_ERR(bb);
>		goto exit;
>	}
>
> -	write_cs_mi_lri(bb, reg_lri, 1);
> +	write_cs_mi_lri(bb, reg_lri, count);
>
> -	fence = xe_oa_submit_bb(stream, XE_OA_SUBMIT_NO_DEPS, bb);
> +	fence = xe_oa_submit_bb(stream, q, XE_OA_SUBMIT_ADD_DEPS, bb);
>	if (IS_ERR(fence)) {
>		err = PTR_ERR(fence);
>		goto free_bb;
> @@ -762,71 +734,55 @@ static int xe_oa_load_with_lri(struct xe_oa_stream *stream, struct xe_oa_reg *re
>  static int xe_oa_configure_oar_context(struct xe_oa_stream *stream, bool enable)
>  {
>	const struct xe_oa_format *format = stream->oa_buffer.format;
> -	struct xe_lrc *lrc = stream->exec_q->lrc[0];
> -	u32 regs_offset = xe_lrc_regs_offset(lrc) / sizeof(u32);
>	u32 oacontrol = __format_to_oactrl(format, OAR_OACONTROL_COUNTER_SEL_MASK) |
>		(enable ? OAR_OACONTROL_COUNTER_ENABLE : 0);
>
> -	struct flex regs_context[] = {
> +	struct xe_oa_reg reg_lri[] = {
>		{
>			OACTXCONTROL(stream->hwe->mmio_base),
> -			stream->oa->ctx_oactxctrl_offset[stream->hwe->class] + 1,
>			enable ? OA_COUNTER_RESUME : 0,
>		},
> +		{
> +			OAR_OACONTROL,
> +			oacontrol,
> +		},
>		{
>			RING_CONTEXT_CONTROL(stream->hwe->mmio_base),
> -			regs_offset + CTX_CONTEXT_CONTROL,
> -			_MASKED_BIT_ENABLE(CTX_CTRL_OAC_CONTEXT_ENABLE),
> +			_MASKED_BIT_ENABLE(enable ? CTX_CTRL_OAC_CONTEXT_ENABLE : 0),

Hmm this does not work because when enable is 0, we are setting bit 0
rather than resetting bit 8 :)

We need to go back to using _MASKED_FIELD which was changed in 0c8650b09a36
("drm/xe/oa: Don't reset OAC_CONTEXT_ENABLE on OA stream close") or do
something else.

>		},
>	};
> -	struct xe_oa_reg reg_lri = { OAR_OACONTROL, oacontrol };
> -	int err;
> -
> -	/* Modify stream hwe context image with regs_context */
> -	err = xe_oa_modify_ctx_image(stream, stream->exec_q->lrc[0],
> -				     regs_context, ARRAY_SIZE(regs_context));
> -	if (err)
> -		return err;
>
>	/* Apply reg_lri using LRI */
> -	return xe_oa_load_with_lri(stream, &reg_lri);
> +	return xe_oa_load_with_lri(stream, reg_lri, ARRAY_SIZE(reg_lri));
>  }
>
>  static int xe_oa_configure_oac_context(struct xe_oa_stream *stream, bool enable)
>  {
>	const struct xe_oa_format *format = stream->oa_buffer.format;
> -	struct xe_lrc *lrc = stream->exec_q->lrc[0];
> -	u32 regs_offset = xe_lrc_regs_offset(lrc) / sizeof(u32);
>	u32 oacontrol = __format_to_oactrl(format, OAR_OACONTROL_COUNTER_SEL_MASK) |
>		(enable ? OAR_OACONTROL_COUNTER_ENABLE : 0);
> -	struct flex regs_context[] = {
> +	struct xe_oa_reg reg_lri[] = {
>		{
>			OACTXCONTROL(stream->hwe->mmio_base),
> -			stream->oa->ctx_oactxctrl_offset[stream->hwe->class] + 1,
>			enable ? OA_COUNTER_RESUME : 0,
>		},
> +		{
> +			OAC_OACONTROL,
> +			oacontrol
> +		},
>		{
>			RING_CONTEXT_CONTROL(stream->hwe->mmio_base),
> -			regs_offset + CTX_CONTEXT_CONTROL,
> -			_MASKED_BIT_ENABLE(CTX_CTRL_OAC_CONTEXT_ENABLE) |
> +			_MASKED_BIT_ENABLE(enable ? CTX_CTRL_OAC_CONTEXT_ENABLE : 0) |

Same comment here as for OAR above.

Thanks.
--
Ashutosh


>			_MASKED_FIELD(CTX_CTRL_RUN_ALONE, enable ? CTX_CTRL_RUN_ALONE : 0),
>		},
>	};
> -	struct xe_oa_reg reg_lri = { OAC_OACONTROL, oacontrol };
> -	int err;
>
>	/* Set ccs select to enable programming of OAC_OACONTROL */
>	xe_mmio_write32(&stream->gt->mmio, __oa_regs(stream)->oa_ctrl,
>			__oa_ccs_select(stream));
>
> -	/* Modify stream hwe context image with regs_context */
> -	err = xe_oa_modify_ctx_image(stream, stream->exec_q->lrc[0],
> -				     regs_context, ARRAY_SIZE(regs_context));
> -	if (err)
> -		return err;
> -
>	/* Apply reg_lri using LRI */
> -	return xe_oa_load_with_lri(stream, &reg_lri);
> +	return xe_oa_load_with_lri(stream, reg_lri, ARRAY_SIZE(reg_lri));
>  }
>
>  static int xe_oa_configure_oa_context(struct xe_oa_stream *stream, bool enable)
> @@ -1023,6 +979,7 @@ static const struct dma_fence_ops xe_oa_fence_ops = {
>  static int xe_oa_emit_oa_config(struct xe_oa_stream *stream, struct xe_oa_config *config)
>  {
>  #define NOA_PROGRAM_ADDITIONAL_DELAY_US 500
> +	struct xe_exec_queue *q = stream->exec_q ?: stream->k_exec_q;
>	struct xe_oa_config_bo *oa_bo;
>	struct xe_oa_fence *ofence;
>	int i, err, num_signal = 0;
> @@ -1041,7 +998,7 @@ static int xe_oa_emit_oa_config(struct xe_oa_stream *stream, struct xe_oa_config
>	}
>
>	/* Emit OA configuration batch */
> -	fence = xe_oa_submit_bb(stream, XE_OA_SUBMIT_ADD_DEPS, oa_bo->bb);
> +	fence = xe_oa_submit_bb(stream, q, XE_OA_SUBMIT_ADD_DEPS, oa_bo->bb);
>	if (IS_ERR(fence)) {
>		err = PTR_ERR(fence);
>		goto exit;
> diff --git a/drivers/gpu/drm/xe/xe_ring_ops.c b/drivers/gpu/drm/xe/xe_ring_ops.c
> index 3a75a08b6be9..c8ab37fa0d19 100644
> --- a/drivers/gpu/drm/xe/xe_ring_ops.c
> +++ b/drivers/gpu/drm/xe/xe_ring_ops.c
> @@ -223,7 +223,10 @@ static int emit_pipe_imm_ggtt(u32 addr, u32 value, bool stall_only, u32 *dw,
>
>  static u32 get_ppgtt_flag(struct xe_sched_job *job)
>  {
> -	return job->q->vm ? BIT(8) : 0;
> +	if (job->q->vm && !job->ggtt)
> +		return BIT(8);
> +
> +	return 0;
>  }
>
>  static int emit_copy_timestamp(struct xe_lrc *lrc, u32 *dw, int i)
> diff --git a/drivers/gpu/drm/xe/xe_sched_job_types.h b/drivers/gpu/drm/xe/xe_sched_job_types.h
> index f13f333f00be..d942b20a9f29 100644
> --- a/drivers/gpu/drm/xe/xe_sched_job_types.h
> +++ b/drivers/gpu/drm/xe/xe_sched_job_types.h
> @@ -56,6 +56,8 @@ struct xe_sched_job {
>	u32 migrate_flush_flags;
>	/** @ring_ops_flush_tlb: The ring ops need to flush TLB before payload. */
>	bool ring_ops_flush_tlb;
> +	/** @ggtt: mapped in ggtt. */
> +	bool ggtt;
>	/** @ptrs: per instance pointers. */
>	struct xe_job_ptrs ptrs[];
>  };
> --
> 2.34.1
>


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