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44
45
46 /**
47 * @file
48 *
49 * Module to support operations on bitmap of cores. Coremask can be used to
50 * select a specific core, a group of cores, or all available cores, for
51 * initialization and differentiation of roles within a single shared binary
52 * executable image.
53 *
54 * <hr>$Revision: 70030 $<hr>
55 *
56 */
57
58 #include "cvmx-config.h"
59 #include "cvmx.h"
60 #include "cvmx-spinlock.h"
61 #include "cvmx-coremask.h"
62
63
64 #define CVMX_COREMASK_MAX_SYNCS 20 /* maximum number of coremasks for barrier sync */
65
66 /**
67 * This structure defines the private state maintained by coremask module.
68 *
69 */
70 CVMX_SHARED static struct {
71
72 cvmx_spinlock_t lock; /**< mutex spinlock */
73
74 struct {
75
76 unsigned int coremask; /**< coremask specified for barrier */
77 unsigned int checkin; /**< bitmask of cores checking in */
78 volatile unsigned int exit; /**< variable to poll for exit condition */
79
80 } s[CVMX_COREMASK_MAX_SYNCS];
81
82 } state = {
83
84 { CVMX_SPINLOCK_UNLOCKED_VAL },
85
86 { { 0, 0, 0 } },
87 };
88
89
90 /**
91 * Wait (stall) until all cores in the given coremask has reached this point
92 * in the program execution before proceeding.
93 *
94 * @param coremask the group of cores performing the barrier sync
95 *
96 */
cvmx_coremask_barrier_sync(unsigned int coremask)97 void cvmx_coremask_barrier_sync(unsigned int coremask)
98 {
99 int i;
100 unsigned int target;
101
102 assert(coremask != 0);
103
104 cvmx_spinlock_lock(&state.lock);
105
106 for (i = 0; i < CVMX_COREMASK_MAX_SYNCS; i++) {
107
108 if (state.s[i].coremask == 0) {
109 /* end of existing coremask list, create new entry, fall-thru */
110 state.s[i].coremask = coremask;
111 }
112
113 if (state.s[i].coremask == coremask) {
114
115 target = state.s[i].exit + 1; /* wrap-around at 32b */
116
117 state.s[i].checkin |= cvmx_coremask_core(cvmx_get_core_num());
118 if (state.s[i].checkin == coremask) {
119 state.s[i].checkin = 0;
120 state.s[i].exit = target; /* signal exit condition */
121 }
122 cvmx_spinlock_unlock(&state.lock);
123
124 while (state.s[i].exit != target)
125 ;
126
127 return;
128 }
129 }
130
131 /* error condition - coremask array overflowed */
132 cvmx_spinlock_unlock(&state.lock);
133 assert(0);
134 }
135