1/* Copyright (c) 2007-2009, Stanford University
2* All rights reserved.
3*
4* Redistribution and use in source and binary forms, with or without
5* modification, are permitted provided that the following conditions are met:
6*     * Redistributions of source code must retain the above copyright
7*       notice, this list of conditions and the following disclaimer.
8*     * Redistributions in binary form must reproduce the above copyright
9*       notice, this list of conditions and the following disclaimer in the
10*       documentation and/or other materials provided with the distribution.
11*     * Neither the name of Stanford University nor the names of its
12*       contributors may be used to endorse or promote products derived from
13*       this software without specific prior written permission.
14*
15* THIS SOFTWARE IS PROVIDED BY STANFORD UNIVERSITY ``AS IS'' AND ANY
16* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18* DISCLAIMED. IN NO EVENT SHALL STANFORD UNIVERSITY BE LIABLE FOR ANY
19* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
21* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
22* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
24* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25*/
26
27#include <assert.h>
28
29#include "scheduler.h"
30#include "locality.h"
31#include "processor.h"
32
33/* TODO: Detect this automatically. */
34#ifdef _SOLARIS_
35#define NUM_CORES_PER_CHIP      8
36#define NUM_STRANDS_PER_CORE    8
37#endif
38
39static int map_fill_strand(sched_policy* sp, int thr);
40static int map_fill_core(sched_policy* sp, int thr);
41static int map_fill_chip(sched_policy* sp, int thr);
42
43struct sched_policy
44{
45    int     num_cpus;
46    int     num_chips_per_sys;
47    int     (*map)(sched_policy* sp, int thr_idx);
48};
49
50struct sched_policy policies[SCHED_POLICY_LAST + 1] = {
51    { .map = map_fill_strand },
52    { .map = map_fill_core },
53    { .map = map_fill_chip },
54};
55
56sched_policy* sched_policy_get(unsigned int policy)
57{
58    assert (policy <= SCHED_POLICY_LAST);
59    /* XXX make this configurable */
60    policies[policy].num_cpus = proc_get_num_cpus();
61    policies[policy].num_chips_per_sys = loc_get_num_lgrps ();
62    return &policies[policy];
63}
64
65void sched_policy_put(sched_policy* sp)
66{
67    /* STUB */
68}
69
70/**
71 * Given a thread index, gives the cpu it should be assigned to.
72 */
73int sched_thr_to_cpu(sched_policy* sp, int thr)
74{
75    return sp->map(sp, thr);
76}
77
78static int map_fill_strand(sched_policy* sp, int thr)
79{
80    int num_cpus = sp->num_cpus;
81    return (thr % num_cpus);
82}
83
84static int map_fill_core(sched_policy* sp, int thr)
85{
86    int num_cpus = sp->num_cpus;
87
88#ifdef NUM_CORES_PER_CHIP
89    int core, strand;
90
91    thr %= num_cpus;
92    core = thr % (NUM_CORES_PER_CHIP * sp->num_chips_per_sys);
93    strand = (thr / (NUM_CORES_PER_CHIP * sp->num_chips_per_sys));
94    strand %= NUM_STRANDS_PER_CORE;
95    return (core * NUM_STRANDS_PER_CORE + strand);
96#else
97    return thr % num_cpus;
98#endif
99}
100
101static int map_fill_chip(sched_policy* sp, int thr)
102{
103    int num_cpus = sp->num_cpus;
104
105#ifdef NUM_CORES_PER_CHIP
106    int chip,  core, strand;
107
108    thr %= num_cpus;
109
110    chip = thr % sp->num_chips_per_sys;
111    core = (thr / sp->num_chips_per_sys) % NUM_CORES_PER_CHIP;
112    strand = thr / (NUM_CORES_PER_CHIP * NUM_STRANDS_PER_CORE);
113    strand %= NUM_STRANDS_PER_CORE;
114
115    return (chip * (NUM_CORES_PER_CHIP * NUM_STRANDS_PER_CORE) +
116            core * (NUM_STRANDS_PER_CORE) +
117            strand);
118#else
119    return thr % num_cpus;
120#endif
121}
122