gem5  v22.1.0.0
BankedArray.cc
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1 /*
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28  * Author: Brad Beckmann
29  *
30  */
31 
33 
34 #include "base/intmath.hh"
36 #include "sim/cur_tick.hh"
37 
38 namespace gem5
39 {
40 
41 namespace ruby
42 {
43 
44 BankedArray::BankedArray(unsigned int banks, Cycles accessLatency,
45  unsigned int startIndexBit, RubySystem *rs)
46  : m_ruby_system(rs)
47 {
48  this->banks = banks;
49  this->accessLatency = accessLatency;
50  this->startIndexBit = startIndexBit;
51 
52  if (banks != 0) {
54  }
55 
56  busyBanks.resize(banks);
57 }
58 
59 bool
61 {
62  if (accessLatency == 0)
63  return true;
64 
65  unsigned int bank = mapIndexToBank(idx);
66  assert(bank < banks);
67 
68  if (busyBanks[bank].endAccess >= curTick()) {
69  return false;
70  }
71 
72  return true;
73 }
74 
75 void
77 {
78  if (accessLatency == 0)
79  return;
80 
81  unsigned int bank = mapIndexToBank(idx);
82  assert(bank < banks);
83 
84  if (busyBanks[bank].endAccess >= curTick()) {
85  if (busyBanks[bank].startAccess == curTick() &&
86  busyBanks[bank].idx == idx) {
87  // this is the same reservation (can happen when
88  // e.g., reserve the same resource for read and write)
89  return; // OK
90  } else {
91  panic("BankedArray reservation error");
92  }
93  }
94 
95  busyBanks[bank].idx = idx;
96  busyBanks[bank].startAccess = curTick();
97  busyBanks[bank].endAccess = curTick() +
99 }
100 
101 unsigned int
103 {
104  if (banks == 1) {
105  return 0;
106  }
107  return idx % banks;
108 }
109 
110 } // namespace ruby
111 } // namespace gem5
Tick clockPeriod() const
Cycles is a wrapper class for representing cycle counts, i.e.
Definition: types.hh:79
void reserve(int64_t idx)
Definition: BankedArray.cc:76
std::vector< AccessRecord > busyBanks
Definition: BankedArray.hh:66
RubySystem * m_ruby_system
Definition: BankedArray.hh:53
bool tryAccess(int64_t idx)
Definition: BankedArray.cc:60
BankedArray(unsigned int banks, Cycles accessLatency, unsigned int startIndexBit, RubySystem *rs)
Definition: BankedArray.cc:44
unsigned int startIndexBit
Definition: BankedArray.hh:52
unsigned int mapIndexToBank(int64_t idx)
Definition: BankedArray.cc:102
static constexpr std::enable_if_t< std::is_integral_v< T >, int > floorLog2(T x)
Definition: intmath.hh:59
#define panic(...)
This implements a cprintf based panic() function.
Definition: logging.hh:178
Bitfield< 9, 8 > rs
Definition: misc_types.hh:383
Reference material can be found at the JEDEC website: UFS standard http://www.jedec....
Tick curTick()
The universal simulation clock.
Definition: cur_tick.hh:46

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