linux_dsm_epyc7002/drivers/gpu/drm/i915/i915_gem_context.h
Chris Wilson 288f1ced5e drm/i915: Reduce context HW ID lifetime
Future gen reduce the number of bits we will have available to
differentiate between contexts, so reduce the lifetime of the ID
assignment from that of the context to its current active cycle (i.e.
only while it is pinned for use by the HW, will it have a constant ID).
This means that instead of a max of 2k allocated contexts (worst case
before fun with bit twiddling), we instead have a limit of 2k in flight
contexts (minus a few that have been pinned by the kernel or by perf).

To reduce the number of contexts id we require, we allocate a context id
on first and mark it as pinned for as long as the GEM context itself is,
that is we keep it pinned it while active on each engine. If we exhaust
our context id space, then we try to reclaim an id from an idle context.
In the extreme case where all context ids are pinned by active contexts,
we force the system to idle in order to recover ids.

We cannot reduce the scope of an HW-ID to an engine (allowing the same
gem_context to have different ids on each engine) as in the future we
will need to preassign an id before we know which engine the
context is being executed on.

v2: Improved commentary (Tvrtko) [I tried at least]

References: https://bugs.freedesktop.org/show_bug.cgi?id=107788
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Michel Thierry <michel.thierry@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180904153117.3907-1-chris@chris-wilson.co.uk
2018-09-05 11:58:08 +01:00

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C

/*
* Copyright © 2016 Intel Corporation
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
*/
#ifndef __I915_GEM_CONTEXT_H__
#define __I915_GEM_CONTEXT_H__
#include <linux/bitops.h>
#include <linux/list.h>
#include <linux/radix-tree.h>
#include "i915_gem.h"
#include "i915_scheduler.h"
struct pid;
struct drm_device;
struct drm_file;
struct drm_i915_private;
struct drm_i915_file_private;
struct i915_hw_ppgtt;
struct i915_request;
struct i915_vma;
struct intel_ring;
#define DEFAULT_CONTEXT_HANDLE 0
struct intel_context;
struct intel_context_ops {
void (*unpin)(struct intel_context *ce);
void (*destroy)(struct intel_context *ce);
};
/**
* struct i915_gem_context - client 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 {
/** i915: i915 device backpointer */
struct drm_i915_private *i915;
/** 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.
*
* In other modes, this is a NULL pointer with the expectation that
* the caller uses the shared global GTT.
*/
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.
*/
const char *name;
/** link: place with &drm_i915_private.context_list */
struct list_head link;
struct llist_node free_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). See i915_gem_context_get() and
* i915_gem_context_put() for access.
*/
struct kref ref;
/**
* @rcu: rcu_head for deferred freeing.
*/
struct rcu_head rcu;
/**
* @flags: small set of booleans
*/
unsigned long flags;
#define CONTEXT_NO_ZEROMAP BIT(0)
#define CONTEXT_NO_ERROR_CAPTURE 1
#define CONTEXT_CLOSED 2
#define CONTEXT_BANNABLE 3
#define CONTEXT_BANNED 4
#define CONTEXT_FORCE_SINGLE_SUBMISSION 5
/**
* @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.
*
* @hw_id_pin_count: - number of times this context had been pinned
* for use (should be, at most, once per engine).
*
* @hw_id_link: - all contexts with an assigned id are tracked
* for possible repossession.
*/
unsigned int hw_id;
atomic_t hw_id_pin_count;
struct list_head hw_id_link;
/**
* @user_handle: userspace identifier
*
* A unique per-file identifier is generated from
* &drm_i915_file_private.contexts.
*/
u32 user_handle;
struct i915_sched_attr sched;
/** engine: per-engine logical HW state */
struct intel_context {
struct i915_gem_context *gem_context;
struct i915_vma *state;
struct intel_ring *ring;
u32 *lrc_reg_state;
u64 lrc_desc;
int pin_count;
const struct intel_context_ops *ops;
} __engine[I915_NUM_ENGINES];
/** ring_size: size for allocating the per-engine ring buffer */
u32 ring_size;
/** desc_template: invariant fields for the HW context descriptor */
u32 desc_template;
/** guilty_count: How many times this context has caused a GPU hang. */
atomic_t guilty_count;
/**
* @active_count: How many times this context was active during a GPU
* hang, but did not cause it.
*/
atomic_t active_count;
#define CONTEXT_SCORE_GUILTY 10
#define CONTEXT_SCORE_BAN_THRESHOLD 40
/** ban_score: Accumulated score of all hangs caused by this context. */
atomic_t ban_score;
/** remap_slice: Bitmask of cache lines that need remapping */
u8 remap_slice;
/** handles_vma: rbtree to look up our context specific obj/vma for
* the user handle. (user handles are per fd, but the binding is
* per vm, which may be one per context or shared with the global GTT)
*/
struct radix_tree_root handles_vma;
/** handles_list: reverse list of all the rbtree entries in use for
* this context, which allows us to free all the allocations on
* context close.
*/
struct list_head handles_list;
};
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)
{
__set_bit(CONTEXT_NO_ERROR_CAPTURE, &ctx->flags);
}
static inline void i915_gem_context_clear_no_error_capture(struct i915_gem_context *ctx)
{
__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_clear_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);
}
int __i915_gem_context_pin_hw_id(struct i915_gem_context *ctx);
static inline int i915_gem_context_pin_hw_id(struct i915_gem_context *ctx)
{
if (atomic_inc_not_zero(&ctx->hw_id_pin_count))
return 0;
return __i915_gem_context_pin_hw_id(ctx);
}
static inline void i915_gem_context_unpin_hw_id(struct i915_gem_context *ctx)
{
GEM_BUG_ON(atomic_read(&ctx->hw_id_pin_count) == 0u);
atomic_dec(&ctx->hw_id_pin_count);
}
static inline bool i915_gem_context_is_default(const struct i915_gem_context *c)
{
return c->user_handle == DEFAULT_CONTEXT_HANDLE;
}
static inline bool i915_gem_context_is_kernel(struct i915_gem_context *ctx)
{
return !ctx->file_priv;
}
static inline struct intel_context *
to_intel_context(struct i915_gem_context *ctx,
const struct intel_engine_cs *engine)
{
return &ctx->__engine[engine->id];
}
static inline struct intel_context *
intel_context_pin(struct i915_gem_context *ctx, struct intel_engine_cs *engine)
{
return engine->context_pin(engine, ctx);
}
static inline void __intel_context_pin(struct intel_context *ce)
{
GEM_BUG_ON(!ce->pin_count);
ce->pin_count++;
}
static inline void intel_context_unpin(struct intel_context *ce)
{
GEM_BUG_ON(!ce->pin_count);
if (--ce->pin_count)
return;
GEM_BUG_ON(!ce->ops);
ce->ops->unpin(ce);
}
/* i915_gem_context.c */
int __must_check i915_gem_contexts_init(struct drm_i915_private *dev_priv);
void i915_gem_contexts_lost(struct drm_i915_private *dev_priv);
void i915_gem_contexts_fini(struct drm_i915_private *dev_priv);
int i915_gem_context_open(struct drm_i915_private *i915,
struct drm_file *file);
void i915_gem_context_close(struct drm_file *file);
int i915_switch_context(struct i915_request *rq);
int i915_gem_switch_to_kernel_context(struct drm_i915_private *dev_priv);
void i915_gem_context_release(struct kref *ctx_ref);
struct i915_gem_context *
i915_gem_context_create_gvt(struct drm_device *dev);
int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
struct drm_file *file);
int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
struct drm_file *file);
int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv);
int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
struct drm_file *file_priv);
int i915_gem_context_reset_stats_ioctl(struct drm_device *dev, void *data,
struct drm_file *file);
struct i915_gem_context *
i915_gem_context_create_kernel(struct drm_i915_private *i915, int prio);
static inline struct i915_gem_context *
i915_gem_context_get(struct i915_gem_context *ctx)
{
kref_get(&ctx->ref);
return ctx;
}
static inline void i915_gem_context_put(struct i915_gem_context *ctx)
{
kref_put(&ctx->ref, i915_gem_context_release);
}
#endif /* !__I915_GEM_CONTEXT_H__ */