Re: [Intel-xe] [PATCH 02/21] drm/xe/oa: Add OA types

[Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>]

On Tue, Sep 19, 2023 at 09:10:30AM -0700, Ashutosh Dixit wrote:
>Add types and data structs used by OA. The data structs maintain device and
>gt level information, information about the open OA stream and OA buffer
>used internally to capture OA counters written by HW as well as capture
>configurations which can be selected for an OA stream.
>
>v2: Add linux includes to fix build
>v3: Change oa_unit_id to u16 (Umesh)
>
>Signed-off-by: Ashutosh Dixit <ashutosh.dixit@intel.com>

lgtm,

Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Umesh
>---
> drivers/gpu/drm/xe/xe_oa_types.h | 295 +++++++++++++++++++++++++++++++
> 1 file changed, 295 insertions(+)
> create mode 100644 drivers/gpu/drm/xe/xe_oa_types.h
>
>diff --git a/drivers/gpu/drm/xe/xe_oa_types.h b/drivers/gpu/drm/xe/xe_oa_types.h
>new file mode 100644
>index 0000000000000..4063c81e353ff
>--- /dev/null
>+++ b/drivers/gpu/drm/xe/xe_oa_types.h
>@@ -0,0 +1,295 @@
>+/* SPDX-License-Identifier: MIT */
>+/*
>+ * Copyright © 2023 Intel Corporation
>+ */
>+
>+#ifndef _XE_OA_TYPES_H_
>+#define _XE_OA_TYPES_H__
>+
>+#include <linux/idr.h>
>+#include <linux/kobject.h>
>+#include <linux/poll.h>
>+#include <linux/sysfs.h>
>+#include <drm/xe_drm.h>
>+#include "regs/xe_reg_defs.h"
>+
>+struct drm_device;
>+struct drm_file;
>+
>+enum {
>+	OA_GROUP_OAG = 0,
>+	OA_GROUP_OAM_SAMEDIA_0 = 0,
>+
>+	OA_GROUP_MAX,
>+	OA_GROUP_INVALID = U32_MAX,
>+};
>+
>+enum oa_type {
>+	TYPE_OAG,
>+	TYPE_OAM,
>+};
>+
>+enum report_header {
>+	HDR_32_BIT = 0,
>+	HDR_64_BIT,
>+};
>+
>+struct xe_oa_format {
>+	u32 format;
>+	int size;
>+	int type;
>+	enum report_header header;
>+};
>+
>+struct xe_oa_reg {
>+	struct xe_reg addr;
>+	u32 value;
>+};
>+
>+struct xe_oa_config {
>+	struct xe_oa *oa;
>+
>+	char uuid[UUID_STRING_LEN + 1];
>+	int id;
>+
>+	const struct xe_oa_reg *mux_regs;
>+	u32 mux_regs_len;
>+	const struct xe_oa_reg *b_counter_regs;
>+	u32 b_counter_regs_len;
>+	const struct xe_oa_reg *flex_regs;
>+	u32 flex_regs_len;
>+
>+	struct attribute_group sysfs_metric;
>+	struct attribute *attrs[2];
>+	struct kobj_attribute sysfs_metric_id;
>+
>+	struct kref ref;
>+	struct rcu_head rcu;
>+};
>+
>+struct xe_oa_regs {
>+	u32 base;
>+	struct xe_reg oa_head_ptr;
>+	struct xe_reg oa_tail_ptr;
>+	struct xe_reg oa_buffer;
>+	struct xe_reg oa_ctx_ctrl;
>+	struct xe_reg oa_ctrl;
>+	struct xe_reg oa_debug;
>+	struct xe_reg oa_status;
>+	u32 oa_ctrl_counter_format_shift;
>+};
>+
>+/**
>+ * struct xe_oa_group - OA group representing one hardware OA unit
>+ */
>+struct xe_oa_group {
>+	/** @oa_unit_id: identifier for the OA unit */
>+	u16 oa_unit_id;
>+
>+	/**
>+	 * @exclusive_stream: The stream currently using the OA unit. This is
>+	 * sometimes accessed outside a syscall associated to its file
>+	 * descriptor.
>+	 */
>+	struct xe_oa_stream *exclusive_stream;
>+
>+	/** @num_engines: number of engines using this OA unit */
>+	u32 num_engines;
>+
>+	/** @regs: OA buffer register group for programming the OA unit */
>+	struct xe_oa_regs regs;
>+
>+	/** @type: Type of OA unit - OAM, OAG etc. */
>+	enum oa_type type;
>+};
>+
>+/**
>+ * struct xe_oa_gt - OA per-gt information
>+ */
>+struct xe_oa_gt {
>+	/** @lock: lock associated with anything below within this structure */
>+	struct mutex lock;
>+
>+	/** @num_oa_groups: number of oa groups per gt */
>+	u32 num_oa_groups;
>+
>+	/** @group: list of OA groups - one for each OA buffer */
>+	struct xe_oa_group *group;
>+};
>+
>+/**
>+ * struct xe_oa - OA device level information
>+ */
>+struct xe_oa {
>+	/** @xe: back pointer to xe device */
>+	struct xe_device *xe;
>+
>+	/** @metrics_kobj: kobj for metrics sysfs */
>+	struct kobject *metrics_kobj;
>+
>+	/**
>+	 * @metrics_lock: lock associated with adding/modifying/removing OA
>+	 * configs in oa->metrics_idr.
>+	 */
>+	struct mutex metrics_lock;
>+
>+	/**
>+	 * @metrics_idr: List of dynamic configurations (struct xe_oa_config)
>+	 */
>+	struct idr metrics_idr;
>+
>+	/** @ctx_oactxctrl_offset: offset of OACTXCONTROL register in context image */
>+	u32 ctx_oactxctrl_offset;
>+
>+	/** @oa_formats: tracks all OA formats across platforms */
>+	const struct xe_oa_format *oa_formats;
>+
>+#define FORMAT_MASK_SIZE DIV_ROUND_UP(XE_OA_FORMAT_MAX - 1, BITS_PER_LONG)
>+
>+	/** @format_mask: tracks valid OA formats for a platform */
>+	unsigned long format_mask[FORMAT_MASK_SIZE];
>+
>+	/** @oa_unit_ids: tracks oa unit ids assigned across gt's */
>+	u16 oa_unit_ids;
>+};
>+
>+/**
>+ * struct xe_oa_stream - state for a single open stream FD
>+ */
>+struct xe_oa_stream {
>+	/** @oa: xe_oa backpointer */
>+	struct xe_oa *oa;
>+
>+	/** @gt: gt associated with the oa stream */
>+	struct xe_gt *gt;
>+
>+	/**
>+	 * @hwe: hardware engine associated with this performance stream.
>+	 */
>+	struct xe_hw_engine *hwe;
>+
>+	/** @lock: Lock associated with operations on stream */
>+	struct mutex lock;
>+
>+	/**
>+	 * @sample: true when DRM_XE_OA_PROP_SAMPLE_OA is given when
>+	 * opening a stream, representing the contents of a single sample
>+	 * as read() by userspace.
>+	 */
>+	bool sample;
>+
>+	/**
>+	 * @sample_size: Considering the configured contents of a sample
>+	 * combined with the required header size, this is the total size
>+	 * of a single sample record.
>+	 */
>+	int sample_size;
>+
>+	/**
>+	 * @exec_q: %NULL if measuring system-wide across all exec_q's or a
>+	 * specific exec_q that is being monitored.
>+	 */
>+	struct xe_exec_queue *exec_q;
>+
>+	/**
>+	 * @enabled: Whether the stream is currently enabled, considering
>+	 * whether the stream was opened in a disabled state and based
>+	 * on `XE_OA_IOCTL_ENABLE` and `XE_OA_IOCTL_DISABLE` calls.
>+	 */
>+	bool enabled;
>+
>+	/** @oa_config: The OA configuration used by the stream */
>+	struct xe_oa_config *oa_config;
>+
>+	/**
>+	 * @oa_config_bos: A list of struct i915_oa_config_bo allocated lazily
>+	 * each time @oa_config changes.
>+	 */
>+	struct llist_head oa_config_bos;
>+
>+	/** @specific_ctx_id: id of the context used for filtering reports */
>+	u32 specific_ctx_id;
>+
>+	/** @specific_ctx_id_mask: The mask used to masking specific_ctx_id bits */
>+	u32 specific_ctx_id_mask;
>+
>+	/**
>+	 * @poll_check_timer: High resolution timer that will periodically
>+	 * check for data in the circular OA buffer for notifying userspace
>+	 * (e.g. during a read() or poll()).
>+	 */
>+	struct hrtimer poll_check_timer;
>+
>+	/**
>+	 * @poll_wq: The wait queue that hrtimer callback wakes when it
>+	 * sees data ready to read in the circular OA buffer.
>+	 */
>+	wait_queue_head_t poll_wq;
>+
>+	/** @pollin: Whether there is data available to read */
>+	bool pollin;
>+
>+	/** @periodic: Whether periodic sampling is currently enabled */
>+	bool periodic;
>+
>+	/** @period_exponent: The OA unit sampling frequency is derived from this */
>+	int period_exponent;
>+
>+	/** @oa_buffer: State of the OA buffer */
>+	struct {
>+		/** @format: data format */
>+		const struct xe_oa_format *format;
>+
>+		/** @format: xe_bo backing the OA buffer */
>+		struct xe_bo *bo;
>+
>+		/** @vaddr: mapped vaddr of the OA buffer */
>+		u8 *vaddr;
>+
>+		/** @last_ctx_id: last context id for OA data added */
>+		u32 last_ctx_id;
>+
>+		/**
>+		 * @ptr_lock: 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;
>+
>+		/**
>+		 * @head: 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;
>+
>+		/**
>+		 * @tail: The last verified tail that can be read by userspace.
>+		 */
>+		u32 tail;
>+	} oa_buffer;
>+
>+	/**
>+	 * @poll_oa_period: The period in nanoseconds at which the OA
>+	 * buffer should be checked for available data.
>+	 */
>+	u64 poll_oa_period;
>+};
>+#endif
>-- 
>2.41.0
>