static void crisv32_arbiter_config(int region, int unused_slots)
{
int slot;
int client;
int interval = 0;
/*
* This vector corresponds to the hardware arbiter slots (see
* the hardware documentation for semantics). We initialize
* each slot with a suitable sentinel value outside the valid
* range {0 .. NBR_OF_CLIENTS - 1} and replace them with
* client indexes. Then it's fed to the hardware.
*/
s8 val[NBR_OF_SLOTS];
for (slot = 0; slot < NBR_OF_SLOTS; slot++)
val[slot] = -1;
for (client = 0; client < NBR_OF_CLIENTS; client++) {
int pos;
/* Allocate the requested non-zero number of slots, but
* also give clients with zero-requests one slot each
* while stocks last. We do the latter here, in client
* order. This makes sure zero-request clients are the
* first to get to any spare slots, else those slots
* could, when bandwidth is allocated close to the limit,
* all be allocated to low-index non-zero-request clients
* in the default-fill loop below. Another positive but
* secondary effect is a somewhat better spread of the
* zero-bandwidth clients in the vector, avoiding some of
* the latency that could otherwise be caused by the
* partitioning of non-zero-bandwidth clients at low
* indexes and zero-bandwidth clients at high
* indexes. (Note that this spreading can only affect the
* unallocated bandwidth.) All the above only matters for
* memory-intensive situations, of course.
*/
if (!requested_slots[region][client]) {
/*
* Skip inactive clients. Also skip zero-slot
* allocations in this pass when there are no known
* free slots.
*/
if (!active_clients[region][client]
|| unused_slots <= 0)
continue;
unused_slots--;
/* Only allocate one slot for this client. */
interval = NBR_OF_SLOTS;
} else
interval =
NBR_OF_SLOTS / requested_slots[region][client];
pos = 0;
while (pos < NBR_OF_SLOTS) {
if (val[pos] >= 0)
pos++;
else {
val[pos] = client;
pos += interval;
}
}
}
client = 0;
for (slot = 0; slot < NBR_OF_SLOTS; slot++) {
/*
* Allocate remaining slots in round-robin
* client-number order for active clients. For this
* pass, we ignore requested bandwidth and previous
* allocations.
*/
if (val[slot] < 0) {
int first = client;
while (!active_clients[region][client]) {
client = (client + 1) % NBR_OF_CLIENTS;
if (client == first)
break;
}
val[slot] = client;
client = (client + 1) % NBR_OF_CLIENTS;
}
if (region == EXT_REGION)
REG_WR_INT_VECT(marb, regi_marb, rw_ext_slots, slot,
val[slot]);
else if (region == INT_REGION)
REG_WR_INT_VECT(marb, regi_marb, rw_int_slots, slot,
val[slot]);
}
}
static void crisv32_arbiter_config(int region, int unused_slots)
{
int slot;
int client;
int interval = 0;
/*
*/
s8 val[NBR_OF_SLOTS];
for (slot = 0; slot < NBR_OF_SLOTS; slot++)
val[slot] = -1;
for (client = 0; client < NBR_OF_CLIENTS; client++) {
int pos;
/*
*/
if (!requested_slots[region][client]) {
/*
*/
if (!active_clients[region][client]
|| unused_slots <= 0)
continue;
unused_slots--;
/* */
interval = NBR_OF_SLOTS;
} else
interval =
NBR_OF_SLOTS / requested_slots[region][client];
pos = 0;
while (pos < NBR_OF_SLOTS) {
if (val[pos] >= 0)
pos++;
else {
val[pos] = client;
pos += interval;
}
}
}
client = 0;
for (slot = 0; slot < NBR_OF_SLOTS; slot++) {
/*
*/
if (val[slot] < 0) {
int first = client;
while (!active_clients[region][client]) {
client = (client + 1) % NBR_OF_CLIENTS;
if (client == first)
break;
}
val[slot] = client;
client = (client + 1) % NBR_OF_CLIENTS;
}
if (region == EXT_REGION)
REG_WR_INT_VECT(marb, regi_marb, rw_ext_slots, slot,
val[slot]);
else if (region == INT_REGION)
REG_WR_INT_VECT(marb, regi_marb, rw_int_slots, slot,
val[slot]);
}
}
