[Intel-gfx] [PATCH 2/3] drm/i915: Complete kerneldoc for struct i915_gem_context
Daniel Vetter
daniel at ffwll.ch
Fri Dec 30 19:13:44 UTC 2016
On Fri, Dec 30, 2016 at 09:27:20AM +0000, Chris Wilson wrote:
> The existing kerneldoc was outdated, so time for a refresh.
>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
A few bikesheds below, feel free to pick what you like and ignore the
others. Otherwise:
Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 214 ++++++++++++++++++++++++-----
> drivers/gpu/drm/i915/i915_gem.c | 26 ++--
> drivers/gpu/drm/i915/i915_gem_context.c | 33 ++---
> drivers/gpu/drm/i915/i915_gem_execbuffer.c | 2 +-
> drivers/gpu/drm/i915/i915_gpu_error.c | 2 +-
> drivers/gpu/drm/i915/intel_lrc.c | 2 +-
> 6 files changed, 211 insertions(+), 68 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 00ecbb4da25e..c8617360c912 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1051,44 +1051,118 @@ enum i915_cache_level {
> #define DEFAULT_CONTEXT_HANDLE 0
>
> /**
> - * struct i915_gem_context - as the name implies, represents a context.
> - * @ref: reference count.
> - * @user_handle: userspace tracking identity for this context.
> - * @remap_slice: l3 row remapping information.
> - * @flags: context specific flags:
> - * CONTEXT_NO_ZEROMAP: do not allow mapping things to page 0.
> - * @file_priv: filp associated with this context (NULL for global default
> - * context).
> - * @hang_stats: information about the role of this context in possible GPU
> - * hangs.
> - * @ppgtt: virtual memory space used by this context.
> - * @legacy_hw_ctx: render context backing object and whether it is correctly
> - * initialized (legacy ring submission mechanism only).
> - * @link: link in the global list of contexts.
> + * struct i915_gem_context - client state
> *
> - * Contexts are memory images used by the hardware to store copies of their
> - * internal state.
> + * The struct i915_gem_context represents the combined view of the driver and
> + * logical hardware state for a particular client.
> */
> struct i915_gem_context {
> - struct kref ref;
> + /**
> + * @i915: i915 device backpointer
> + */
> struct drm_i915_private *i915;
Hot of the press, but 4.10 has a new one-line inline format:
/** i915: i915 device backpointer */
Only works if it's really just one line, but perfect for small stuff in
big structs.
Feel free to bikeshed while applying, or not.
> +
> + /**
> + * @file_priv: owning file descriptor
> + */
> struct drm_i915_file_private *file_priv;
> +
> + /**
> + * @ppgtt: unique address space (GTT)
> + *
> + * In full-ppgtt mode, each context has its own address space ensuring
> + * complete seperation of one client from all others.
> + */
> struct i915_hw_ppgtt *ppgtt;
> +
> + /**
> + * @pid: process id of creator
> + *
> + * Note that who created the context may not be the principle user,
> + * as the context may be shared across a local socket. However,
> + * that should only affect the default context, all contexts created
> + * explicitly by the client are expected to be isolated.
> + */
> struct pid *pid;
> +
> + /**
> + * @name: arbitrary name
> + *
> + * A name is constructed for the context from the creator's process
> + * name, pid and user handle in order to uniquely identify the
> + * context in messages.
... debug messages.
> + */
> const char *name;
>
> + /**
> + * @link: place with &drm_i915_private.context_list
> + */
> + struct list_head link;
> +
> + /**
> + * @ref: reference count
> + *
> + * A reference to a context is held by both the client who created it
> + * and on each request submitted to the hardware using the request
> + * (to ensure the hardware has access to the state until it has
> + * finished all pending writes).
> + */
For refcounts I like to point at the functions meant to manipulate it,
here i915_gem_context_get() and i915_gem_context_put(). Seems good
practice in general to mentions the funcs used to manipulate a bit of
data.
> + struct kref ref;
> +
> + /**
> + * @flags: small set of booleans
> + */
> unsigned long flags;
> #define CONTEXT_NO_ZEROMAP BIT(0)
> -#define CONTEXT_NO_ERROR_CAPTURE BIT(1)
> +#define CONTEXT_NO_ERROR_CAPTURE 1
> +#define CONTEXT_CLOSED 2
> +#define CONTEXT_BANNABLE 3
> +#define CONTEXT_BANNED 4
> +#define CONTEXT_FORCE_SINGLE_SUBMISSION 5
>
> - /* Unique identifier for this context, used by the hw for tracking */
> + /**
> + * @hw_id: - unique identifier for the context
> + *
> + * The hardware needs to uniquely identify the context for a few
> + * functions like fault reporting, PASID, scheduling. The
> + * &drm_i915_private.context_hw_ida is used to assign a unqiue
> + * id for the lifetime of the context.
> + */
> unsigned int hw_id;
> +
> + /**
> + * @user_handle: userspace identifier
> + *
> + * A unique per-file identifier is generated from
> + * &drm_i915_file_private.contexts.
> + */
> u32 user_handle;
> - int priority; /* greater priorities are serviced first */
>
> + /**
> + * @priority: execution and service priority
> + *
> + * All clients are equal, but some are more equal than others!
> + *
> + * Requests from a context with a greater (more positive) value of
> + * @priority will be executed before those with a lower @priority
> + * value, forming a simple QoS.
> + *
> + * The kernel_context is assigned the minimum priority.
> + */
> + int priority;
> +
> + /**
> + * @ggtt_alignment: alignment restriction for context objects
> + */
> u32 ggtt_alignment;
> + /**
> + * @ggtt_offset_bias: placement restriction for context objects
> + */
> u32 ggtt_offset_bias;
>
> + /**
> + * @engine: per-engine logical HW state
> + */
> struct intel_context {
> struct i915_vma *state;
> struct intel_ring *ring;
> @@ -1097,27 +1171,105 @@ struct i915_gem_context {
> int pin_count;
> bool initialised;
> } engine[I915_NUM_ENGINES];
> +
> + /**
> + * @ring_size: size for allocating the per-engine ring buffer
> + */
> u32 ring_size;
> + /**
> + * @desc_template: common/invariant fields for the HW context descriptor
> + */
> u32 desc_template;
> - struct atomic_notifier_head status_notifier;
> - bool execlists_force_single_submission;
> -
> - struct list_head link;
>
> - u8 remap_slice;
> - bool closed:1;
> - bool bannable:1;
> - bool banned:1;
> + /**
> + * @status_notifier: list of callbacks
> + */
> + struct atomic_notifier_head status_notifier;
>
> - unsigned int guilty_count; /* guilty of a hang */
> - unsigned int active_count; /* active during hang */
> + /**
> + * @guilty_count: How many times this context has caused a GPU hang.
> + */
> + unsigned int guilty_count;
> + /**
> + * @active_count: How many times this context was active during a GPU
> + * hang, but did not cause it.
> + */
> + unsigned int active_count;
>
> #define CONTEXT_SCORE_GUILTY 10
> #define CONTEXT_SCORE_BAN_THRESHOLD 40
> - /* Accumulated score of hangs caused by this context */
> + /**
> + * @ban_score: Accumulated score of all hangs caused by this context.
> + */
> int ban_score;
> +
> + /**
> + * @remap_slice: Bitmask of cache lines that need remapping
> + */
> + u8 remap_slice;
> };
>
> +static inline bool i915_gem_context_is_closed(const struct i915_gem_context *ctx)
> +{
> + return test_bit(CONTEXT_CLOSED, &ctx->flags);
> +}
> +
> +static inline void i915_gem_context_set_closed(struct i915_gem_context *ctx)
> +{
> + GEM_BUG_ON(i915_gem_context_is_closed(ctx));
> + set_bit(CONTEXT_CLOSED, &ctx->flags);
> +}
> +
> +static inline bool i915_gem_context_no_error_capture(const struct i915_gem_context *ctx)
> +{
> + return test_bit(CONTEXT_NO_ERROR_CAPTURE, &ctx->flags);
> +}
> +
> +static inline void i915_gem_context_set_no_error_capture(struct i915_gem_context *ctx)
> +{
> + return set_bit(CONTEXT_NO_ERROR_CAPTURE, &ctx->flags);
> +}
> +
> +static inline void i915_gem_context_unset_no_error_capture(struct i915_gem_context *ctx)
> +{
> + return clear_bit(CONTEXT_NO_ERROR_CAPTURE, &ctx->flags);
> +}
> +
> +static inline bool i915_gem_context_is_bannable(const struct i915_gem_context *ctx)
> +{
> + return test_bit(CONTEXT_BANNABLE, &ctx->flags);
> +}
> +
> +static inline void i915_gem_context_set_bannable(struct i915_gem_context *ctx)
> +{
> + set_bit(CONTEXT_BANNABLE, &ctx->flags);
> +}
> +
> +static inline void i915_gem_context_unset_bannable(struct i915_gem_context *ctx)
> +{
> + clear_bit(CONTEXT_BANNABLE, &ctx->flags);
> +}
> +
> +static inline bool i915_gem_context_is_banned(const struct i915_gem_context *ctx)
> +{
> + return test_bit(CONTEXT_BANNED, &ctx->flags);
> +}
> +
> +static inline void i915_gem_context_set_banned(struct i915_gem_context *ctx)
> +{
> + set_bit(CONTEXT_BANNED, &ctx->flags);
> +}
> +
> +static inline bool i915_gem_context_force_single_submission(const struct i915_gem_context *ctx)
> +{
> + return test_bit(CONTEXT_FORCE_SINGLE_SUBMISSION, &ctx->flags);
> +}
> +
> +static inline void i915_gem_context_set_force_single_submission(struct i915_gem_context *ctx)
> +{
> + set_bit(CONTEXT_FORCE_SINGLE_SUBMISSION, &ctx->flags);
> +}
> +
> enum fb_op_origin {
> ORIGIN_GTT,
> ORIGIN_CPU,
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 92560a776e17..d8760acf8001 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2656,34 +2656,24 @@ void *i915_gem_object_pin_map(struct drm_i915_gem_object *obj,
> goto out_unlock;
> }
>
> -static bool i915_context_is_banned(const struct i915_gem_context *ctx)
> +static bool ban_context(const struct i915_gem_context *ctx)
> {
> - if (ctx->banned)
> - return true;
> -
> - if (!ctx->bannable)
> - return false;
> -
> - if (ctx->ban_score >= CONTEXT_SCORE_BAN_THRESHOLD) {
> - DRM_DEBUG("context hanging too often, banning!\n");
> - return true;
> - }
> -
> - return false;
> + return (i915_gem_context_is_bannable(ctx) &&
> + ctx->ban_score >= CONTEXT_SCORE_BAN_THRESHOLD);
> }
>
> static void i915_gem_context_mark_guilty(struct i915_gem_context *ctx)
> {
> - ctx->ban_score += CONTEXT_SCORE_GUILTY;
> -
> - ctx->banned = i915_context_is_banned(ctx);
> ctx->guilty_count++;
> + ctx->ban_score += CONTEXT_SCORE_GUILTY;
> + if (ban_context(ctx))
> + i915_gem_context_set_banned(ctx);
>
> DRM_DEBUG_DRIVER("context %s marked guilty (score %d) banned? %s\n",
> ctx->name, ctx->ban_score,
> - yesno(ctx->banned));
> + yesno(i915_gem_context_is_banned(ctx)));
>
> - if (!ctx->banned || IS_ERR_OR_NULL(ctx->file_priv))
> + if (!i915_gem_context_is_banned(ctx) || IS_ERR_OR_NULL(ctx->file_priv))
> return;
>
> ctx->file_priv->context_bans++;
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index 48e4ed5bb209..5c0c7064d532 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -141,7 +141,7 @@ void i915_gem_context_free(struct kref *ctx_ref)
>
> lockdep_assert_held(&ctx->i915->drm.struct_mutex);
> trace_i915_context_free(ctx);
> - GEM_BUG_ON(!ctx->closed);
> + GEM_BUG_ON(!i915_gem_context_is_closed(ctx));
>
> i915_ppgtt_put(ctx->ppgtt);
>
> @@ -228,8 +228,7 @@ static void i915_ppgtt_close(struct i915_address_space *vm)
>
> static void context_close(struct i915_gem_context *ctx)
> {
> - GEM_BUG_ON(ctx->closed);
> - ctx->closed = true;
> + i915_gem_context_set_closed(ctx);
> if (ctx->ppgtt)
> i915_ppgtt_close(&ctx->ppgtt->base);
> ctx->file_priv = ERR_PTR(-EBADF);
> @@ -329,7 +328,7 @@ __create_hw_context(struct drm_i915_private *dev_priv,
> * is no remap info, it will be a NOP. */
> ctx->remap_slice = ALL_L3_SLICES(dev_priv);
>
> - ctx->bannable = true;
> + i915_gem_context_set_bannable(ctx);
> ctx->ring_size = 4 * PAGE_SIZE;
> ctx->desc_template = GEN8_CTX_ADDRESSING_MODE(dev_priv) <<
> GEN8_CTX_ADDRESSING_MODE_SHIFT;
> @@ -418,8 +417,9 @@ i915_gem_context_create_gvt(struct drm_device *dev)
> if (IS_ERR(ctx))
> goto out;
>
> - ctx->closed = true; /* not user accessible */
> - ctx->execlists_force_single_submission = true;
> + i915_gem_context_set_closed(ctx); /* not user accessible */
> + i915_gem_context_unset_bannable(ctx);
> + i915_gem_context_set_force_single_submission(ctx);
> ctx->ring_size = 512 * PAGE_SIZE; /* Max ring buffer size */
> out:
> mutex_unlock(&dev->struct_mutex);
> @@ -468,6 +468,7 @@ int i915_gem_context_init(struct drm_i915_private *dev_priv)
> return PTR_ERR(ctx);
> }
>
> + i915_gem_context_unset_bannable(ctx);
> ctx->priority = I915_PRIORITY_MIN; /* lowest priority; idle task */
> dev_priv->kernel_context = ctx;
>
> @@ -1040,10 +1041,10 @@ int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
> args->value = to_i915(dev)->ggtt.base.total;
> break;
> case I915_CONTEXT_PARAM_NO_ERROR_CAPTURE:
> - args->value = !!(ctx->flags & CONTEXT_NO_ERROR_CAPTURE);
> + args->value = i915_gem_context_no_error_capture(ctx);
> break;
> case I915_CONTEXT_PARAM_BANNABLE:
> - args->value = ctx->bannable;
> + args->value = i915_gem_context_is_bannable(ctx);
> break;
> default:
> ret = -EINVAL;
> @@ -1085,22 +1086,22 @@ int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
> }
> break;
> case I915_CONTEXT_PARAM_NO_ERROR_CAPTURE:
> - if (args->size) {
> + if (args->size)
> ret = -EINVAL;
> - } else {
> - if (args->value)
> - ctx->flags |= CONTEXT_NO_ERROR_CAPTURE;
> - else
> - ctx->flags &= ~CONTEXT_NO_ERROR_CAPTURE;
> - }
> + else if (args->value)
> + i915_gem_context_set_no_error_capture(ctx);
> + else
> + i915_gem_context_unset_no_error_capture(ctx);
> break;
> case I915_CONTEXT_PARAM_BANNABLE:
> if (args->size)
> ret = -EINVAL;
> else if (!capable(CAP_SYS_ADMIN) && !args->value)
> ret = -EPERM;
> + else if (args->value)
> + i915_gem_context_set_bannable(ctx);
> else
> - ctx->bannable = args->value;
> + i915_gem_context_unset_bannable(ctx);
> break;
> default:
> ret = -EINVAL;
> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> index c64438f8171c..a5fe299da1d3 100644
> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
> @@ -1238,7 +1238,7 @@ i915_gem_validate_context(struct drm_device *dev, struct drm_file *file,
> if (IS_ERR(ctx))
> return ctx;
>
> - if (ctx->banned) {
> + if (i915_gem_context_is_banned(ctx)) {
> DRM_DEBUG("Context %u tried to submit while banned\n", ctx_id);
> return ERR_PTR(-EIO);
> }
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index e16037d1b0ba..e34532d98004 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -1331,7 +1331,7 @@ static void i915_gem_record_rings(struct drm_i915_private *dev_priv,
> }
>
> error->simulated |=
> - request->ctx->flags & CONTEXT_NO_ERROR_CAPTURE;
> + i915_gem_context_no_error_capture(request->ctx);
>
> ee->rq_head = request->head;
> ee->rq_post = request->postfix;
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index fc64be1bdea7..227978820320 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -413,7 +413,7 @@ static void execlists_submit_ports(struct intel_engine_cs *engine)
> static bool ctx_single_port_submission(const struct i915_gem_context *ctx)
> {
> return (IS_ENABLED(CONFIG_DRM_I915_GVT) &&
> - ctx->execlists_force_single_submission);
> + i915_gem_context_force_single_submission(ctx));
> }
>
> static bool can_merge_ctx(const struct i915_gem_context *prev,
> --
> 2.11.0
>
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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