linux_dsm_epyc7002/drivers/gpu/drm/i915/i915_utils.h
Chris Wilson b887d61546 drm/i915: Retire requests along rings
In the next patch, rings are the central timeline as requests may jump
between engines. Therefore in the future as we retire in order along the
engine timeline, we may retire out-of-order within a ring (as the ring now
occurs along multiple engines), leading to much hilarity in miscomputing
the position of ring->head.

As an added bonus, retiring along the ring reduces the penalty of having
one execlists client do cleanup for another (old legacy submission
shares a ring between all clients). The downside is that slow and
irregular (off the critical path) process of cleaning up stale requests
after userspace becomes a modicum less efficient.

In the long run, it will become apparent that the ordered
ring->request_list matches the ring->timeline, a fun challenge for the
future will be unifying the two lists to avoid duplication!

v2: We need both engine-order and ring-order processing to maintain our
knowledge of where individual rings have completed upto as well as
knowing what was last executing on any engine. And finally by decoupling
retiring the contexts on the engine and the timelines along the rings,
we do have to keep a reference to the context on each request
(previously it was guaranteed by the context being pinned).

v3: Not just a reference to the context, but we need to keep it pinned
as we manipulate the rings; i.e. we need a pin for both the manipulation
of the engine state during its retirements, and a separate pin for the
manipulation of the ring state.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180430131503.5375-3-chris@chris-wilson.co.uk
2018-04-30 16:01:18 +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_UTILS_H
#define __I915_UTILS_H
#undef WARN_ON
/* Many gcc seem to no see through this and fall over :( */
#if 0
#define WARN_ON(x) ({ \
bool __i915_warn_cond = (x); \
if (__builtin_constant_p(__i915_warn_cond)) \
BUILD_BUG_ON(__i915_warn_cond); \
WARN(__i915_warn_cond, "WARN_ON(" #x ")"); })
#else
#define WARN_ON(x) WARN((x), "%s", "WARN_ON(" __stringify(x) ")")
#endif
#undef WARN_ON_ONCE
#define WARN_ON_ONCE(x) WARN_ONCE((x), "%s", "WARN_ON_ONCE(" __stringify(x) ")")
#define MISSING_CASE(x) WARN(1, "Missing case (%s == %ld)\n", \
__stringify(x), (long)(x))
#if GCC_VERSION >= 70000
#define add_overflows(A, B) \
__builtin_add_overflow_p((A), (B), (typeof((A) + (B)))0)
#else
#define add_overflows(A, B) ({ \
typeof(A) a = (A); \
typeof(B) b = (B); \
a + b < a; \
})
#endif
#define range_overflows(start, size, max) ({ \
typeof(start) start__ = (start); \
typeof(size) size__ = (size); \
typeof(max) max__ = (max); \
(void)(&start__ == &size__); \
(void)(&start__ == &max__); \
start__ > max__ || size__ > max__ - start__; \
})
#define range_overflows_t(type, start, size, max) \
range_overflows((type)(start), (type)(size), (type)(max))
/* Note we don't consider signbits :| */
#define overflows_type(x, T) \
(sizeof(x) > sizeof(T) && (x) >> (sizeof(T) * BITS_PER_BYTE))
#define ptr_mask_bits(ptr, n) ({ \
unsigned long __v = (unsigned long)(ptr); \
(typeof(ptr))(__v & -BIT(n)); \
})
#define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
#define ptr_unpack_bits(ptr, bits, n) ({ \
unsigned long __v = (unsigned long)(ptr); \
*(bits) = __v & (BIT(n) - 1); \
(typeof(ptr))(__v & -BIT(n)); \
})
#define ptr_pack_bits(ptr, bits, n) ({ \
unsigned long __bits = (bits); \
GEM_BUG_ON(__bits & -BIT(n)); \
((typeof(ptr))((unsigned long)(ptr) | __bits)); \
})
#define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
#define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
#define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
#define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
#define ptr_offset(ptr, member) offsetof(typeof(*(ptr)), member)
#define fetch_and_zero(ptr) ({ \
typeof(*ptr) __T = *(ptr); \
*(ptr) = (typeof(*ptr))0; \
__T; \
})
static inline u64 ptr_to_u64(const void *ptr)
{
return (uintptr_t)ptr;
}
#define u64_to_ptr(T, x) ({ \
typecheck(u64, x); \
(T *)(uintptr_t)(x); \
})
#define __mask_next_bit(mask) ({ \
int __idx = ffs(mask) - 1; \
mask &= ~BIT(__idx); \
__idx; \
})
#include <linux/list.h>
static inline int list_is_first(const struct list_head *list,
const struct list_head *head)
{
return head->next == list;
}
static inline void __list_del_many(struct list_head *head,
struct list_head *first)
{
first->prev = head;
WRITE_ONCE(head->next, first);
}
/*
* Wait until the work is finally complete, even if it tries to postpone
* by requeueing itself. Note, that if the worker never cancels itself,
* we will spin forever.
*/
static inline void drain_delayed_work(struct delayed_work *dw)
{
do {
while (flush_delayed_work(dw))
;
} while (delayed_work_pending(dw));
}
static inline const char *yesno(bool v)
{
return v ? "yes" : "no";
}
static inline const char *onoff(bool v)
{
return v ? "on" : "off";
}
static inline const char *enableddisabled(bool v)
{
return v ? "enabled" : "disabled";
}
#endif /* !__I915_UTILS_H */