drm/i915/perf: Refactor oa object to better manage resources

The oa object manages the oa buffer and must be allocated when the user
intends to read performance counter snapshots. This can be achieved by
making the oa object part of the stream object which is allocated when a
stream is opened by the user.

Attributes in the oa object that are gen-specific are moved to the perf
object so that they can be initialized on driver load.

The split provides a better separation of the objects used in perf
implementation of i915 driver so that resources are allocated and
initialized only when needed.

v2: Fix checkpatch warnings
v3: Addressed Lionel's review comment
v4: Rebase
v5: Fix rebase/merge issue with ratelimit_state_init

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190806233002.984-1-umesh.nerlige.ramappa@intel.com

1 files changed, 107 insertions, 112 deletions

diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 1f70d9e2fc35..7232e203aab3 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1241,6 +1241,86 @@ struct i915_perf_stream {
 	 * @oa_config: The OA configuration used by the stream.
 	 */
 	struct i915_oa_config *oa_config;
+
+	/**
+	 * The OA context specific information.
+	 */
+	struct intel_context *pinned_ctx;
+	u32 specific_ctx_id;
+	u32 specific_ctx_id_mask;
+
+	struct hrtimer poll_check_timer;
+	wait_queue_head_t poll_wq;
+	bool pollin;
+
+	bool periodic;
+	int period_exponent;
+
+	/**
+	 * State of the OA buffer.
+	 */
+	struct {
+		struct i915_vma *vma;
+		u8 *vaddr;
+		u32 last_ctx_id;
+		int format;
+		int format_size;
+		int size_exponent;
+
+		/**
+		 * Locks reads and writes to all head/tail state
+		 *
+		 * Consider: the head and tail pointer state needs to be read
+		 * consistently from a hrtimer callback (atomic context) and
+		 * read() fop (user context) with tail pointer updates happening
+		 * in atomic context and head updates in user context and the
+		 * (unlikely) possibility of read() errors needing to reset all
+		 * head/tail state.
+		 *
+		 * Note: Contention/performance aren't currently a significant
+		 * concern here considering the relatively low frequency of
+		 * hrtimer callbacks (5ms period) and that reads typically only
+		 * happen in response to a hrtimer event and likely complete
+		 * before the next callback.
+		 *
+		 * Note: This lock is not held *while* reading and copying data
+		 * to userspace so the value of head observed in htrimer
+		 * callbacks won't represent any partial consumption of data.
+		 */
+		spinlock_t ptr_lock;
+
+		/**
+		 * One 'aging' tail pointer and one 'aged' tail pointer ready to
+		 * used for reading.
+		 *
+		 * Initial values of 0xffffffff are invalid and imply that an
+		 * update is required (and should be ignored by an attempted
+		 * read)
+		 */
+		struct {
+			u32 offset;
+		} tails[2];
+
+		/**
+		 * Index for the aged tail ready to read() data up to.
+		 */
+		unsigned int aged_tail_idx;
+
+		/**
+		 * A monotonic timestamp for when the current aging tail pointer
+		 * was read; used to determine when it is old enough to trust.
+		 */
+		u64 aging_timestamp;
+
+		/**
+		 * Although we can always read back the head pointer register,
+		 * we prefer to avoid trusting the HW state, just to avoid any
+		 * risk that some hardware condition could * somehow bump the
+		 * head pointer unpredictably and cause us to forward the wrong
+		 * OA buffer data to userspace.
+		 */
+		u32 head;
+	} oa_buffer;
 };
 
 /**
@@ -1278,7 +1358,7 @@ struct i915_oa_ops {
 	 * @disable_metric_set: Remove system constraints associated with using
 	 * the OA unit.
 	 */
-	void (*disable_metric_set)(struct drm_i915_private *dev_priv);
+	void (*disable_metric_set)(struct i915_perf_stream *stream);
 
 	/**
 	 * @oa_enable: Enable periodic sampling
@@ -1306,7 +1386,7 @@ struct i915_oa_ops {
 	 * handling the OA unit tail pointer race that affects multiple
 	 * generations.
 	 */
-	u32 (*oa_hw_tail_read)(struct drm_i915_private *dev_priv);
+	u32 (*oa_hw_tail_read)(struct i915_perf_stream *stream);
 };
 
 struct intel_cdclk_state {
@@ -1705,120 +1785,35 @@ struct drm_i915_private {
 		struct mutex lock;
 		struct list_head streams;
 
-		struct {
-			/*
-			 * The stream currently using the OA unit. If accessed
-			 * outside a syscall associated to its file
-			 * descriptor, you need to hold
-			 * dev_priv->drm.struct_mutex.
-			 */
-			struct i915_perf_stream *exclusive_stream;
+		/*
+		 * The stream currently using the OA unit. If accessed
+		 * outside a syscall associated to its file
+		 * descriptor, you need to hold
+		 * dev_priv->drm.struct_mutex.
+		 */
+		struct i915_perf_stream *exclusive_stream;
+
+		/**
+		 * For rate limiting any notifications of spurious
+		 * invalid OA reports
+		 */
+		struct ratelimit_state spurious_report_rs;
 
-			struct intel_context *pinned_ctx;
-			u32 specific_ctx_id;
-			u32 specific_ctx_id_mask;
+		struct i915_oa_config test_config;
 
-			struct hrtimer poll_check_timer;
-			wait_queue_head_t poll_wq;
-			bool pollin;
+		u32 gen7_latched_oastatus1;
+		u32 ctx_oactxctrl_offset;
+		u32 ctx_flexeu0_offset;
 
-			/**
-			 * For rate limiting any notifications of spurious
-			 * invalid OA reports
-			 */
-			struct ratelimit_state spurious_report_rs;
-
-			bool periodic;
-			int period_exponent;
-
-			struct i915_oa_config test_config;
-
-			struct {
-				struct i915_vma *vma;
-				u8 *vaddr;
-				u32 last_ctx_id;
-				int format;
-				int format_size;
-
-				/**
-				 * Locks reads and writes to all head/tail state
-				 *
-				 * Consider: the head and tail pointer state
-				 * needs to be read consistently from a hrtimer
-				 * callback (atomic context) and read() fop
-				 * (user context) with tail pointer updates
-				 * happening in atomic context and head updates
-				 * in user context and the (unlikely)
-				 * possibility of read() errors needing to
-				 * reset all head/tail state.
-				 *
-				 * Note: Contention or performance aren't
-				 * currently a significant concern here
-				 * considering the relatively low frequency of
-				 * hrtimer callbacks (5ms period) and that
-				 * reads typically only happen in response to a
-				 * hrtimer event and likely complete before the
-				 * next callback.
-				 *
-				 * Note: This lock is not held *while* reading
-				 * and copying data to userspace so the value
-				 * of head observed in htrimer callbacks won't
-				 * represent any partial consumption of data.
-				 */
-				spinlock_t ptr_lock;
-
-				/**
-				 * One 'aging' tail pointer and one 'aged'
-				 * tail pointer ready to used for reading.
-				 *
-				 * Initial values of 0xffffffff are invalid
-				 * and imply that an update is required
-				 * (and should be ignored by an attempted
-				 * read)
-				 */
-				struct {
-					u32 offset;
-				} tails[2];
-
-				/**
-				 * Index for the aged tail ready to read()
-				 * data up to.
-				 */
-				unsigned int aged_tail_idx;
-
-				/**
-				 * A monotonic timestamp for when the current
-				 * aging tail pointer was read; used to
-				 * determine when it is old enough to trust.
-				 */
-				u64 aging_timestamp;
-
-				/**
-				 * Although we can always read back the head
-				 * pointer register, we prefer to avoid
-				 * trusting the HW state, just to avoid any
-				 * risk that some hardware condition could
-				 * somehow bump the head pointer unpredictably
-				 * and cause us to forward the wrong OA buffer
-				 * data to userspace.
-				 */
-				u32 head;
-			} oa_buffer;
-
-			u32 gen7_latched_oastatus1;
-			u32 ctx_oactxctrl_offset;
-			u32 ctx_flexeu0_offset;
-
-			/**
-			 * The RPT_ID/reason field for Gen8+ includes a bit
-			 * to determine if the CTX ID in the report is valid
-			 * but the specific bit differs between Gen 8 and 9
-			 */
-			u32 gen8_valid_ctx_bit;
+		/**
+		 * The RPT_ID/reason field for Gen8+ includes a bit
+		 * to determine if the CTX ID in the report is valid
+		 * but the specific bit differs between Gen 8 and 9
+		 */
+		u32 gen8_valid_ctx_bit;
 
-			struct i915_oa_ops ops;
-			const struct i915_oa_format *oa_formats;
-		} oa;
+		struct i915_oa_ops ops;
+		const struct i915_oa_format *oa_formats;
 	} perf;
 
 	/* Abstract the submission mechanism (legacy ringbuffer or execlists) away */