int dram_system_get_request(struct dram_system_t *system)
{
unsigned int logical_channel_id;
struct dram_controller_t *controller;
struct dram_request_t *request;
request = list_get(system->dram_request_list, 0);
/* Do nothing if no request is passed */
if (!request)
return 0;
/* Decode request address */
dram_decode_address(system, request->addr, &logical_channel_id,
NULL, NULL, NULL, NULL, NULL);
/* Send request to the request queue*/
/* return 0 if request queue cannot take any request at this moment */
controller = list_get(system->dram_controller_list, logical_channel_id);
if (!dram_controller_get_request(controller, request))
return 0;
/* Return */
return 1;
}
int dram_controller_get_request(struct dram_controller_t *controller, struct dram_request_t *request)
{
int i;
unsigned int rank_id, bank_id, physical_channel_id;
struct dram_bank_info_t *info;
/* Do nothing if pointer is not passed*/
if (!request || !controller)
return 0;
/* Decode address*/
dram_decode_address(request->system, request->addr,
NULL, &rank_id, NULL, &bank_id, NULL, &physical_channel_id);
/* Locate bank info */
i = (physical_channel_id) * (controller->dram_num_ranks) * (controller->dram_num_banks_per_device) + (rank_id) * (controller->dram_num_banks_per_device) + (bank_id);
info = list_get(controller->dram_bank_info_list, i);
list_add(info->request_queue, request);
return 1;
}
void dram_controller_process_request(struct dram_controller_t *controller)
{
int i;
unsigned int num_bank_info;
unsigned int row_id, column_id;
struct dram_request_t *request;
struct dram_bank_info_t *info;
struct dram_command_t *command_precharge;
struct dram_command_t *command_activate;
struct dram_command_t *command_access;
/* Go through bank info list */
num_bank_info = list_count(controller->dram_bank_info_list);
for (i = 0; i < num_bank_info; i++)
{
/* Locate bank info */
info = list_get(controller->dram_bank_info_list, i);
/* Fetch a request from request queue */
request = list_dequeue(info->request_queue);
if (request)
{
dram_decode_address(request->system, request->addr, NULL, NULL,
&row_id, NULL, &column_id, NULL);
/* Determine policy to be used */
switch (controller->rb_policy)
{
/* Open page row buffer policy */
case open_page_row_buffer_policy:
/* Row hit */
if (info->row_buffer_valid && info->active_row_id == row_id)
{
/* Create single read/write command */
command_access = dram_command_create();
command_access->dram = list_get(controller->dram_list, info->channel_id);
if (request->type == request_type_read)
{
command_access->type = dram_command_read;
command_access->u.read.rank_id = info->rank_id;
command_access->u.read.bank_id = info->bank_id;
command_access->u.read.column_id = column_id;
}
else if (request->type == request_type_write)
{
command_access->type = dram_command_write;
command_access->u.write.rank_id = info->rank_id;
command_access->u.write.bank_id = info->bank_id;
command_access->u.write.column_id = column_id;
}
/* Append command to queue */
list_add(info->command_queue, command_access);
}
/* Row miss - different row was activated */
else if (info->row_buffer_valid)
{
/* Create pre, act, rd/wr three commands */
command_precharge = dram_command_create();
command_activate = dram_command_create();
command_access = dram_command_create();
/* Precharge */
command_precharge->type = dram_command_precharge;
command_precharge->dram = list_get(controller->dram_list, info->channel_id);
command_precharge->u.precharge.rank_id = info->rank_id;
command_precharge->u.precharge.bank_id = info->bank_id;
/* Activate */
command_activate->type = dram_command_activate;
command_activate->dram = list_get(controller->dram_list, info->channel_id);
command_activate->u.activate.rank_id = info->rank_id;
command_activate->u.activate.bank_id = info->bank_id;
command_activate->u.activate.row_id = row_id;
/* Access */
command_access->dram = list_get(controller->dram_list, info->channel_id);
if (request->type == request_type_read)
{
command_access->type = dram_command_read;
command_access->u.read.rank_id = info->rank_id;
command_access->u.read.bank_id = info->bank_id;
command_access->u.read.column_id = column_id;
}
else if (request->type == request_type_write)
{
command_access->type = dram_command_write;
command_access->u.write.rank_id = info->rank_id;
command_access->u.write.bank_id = info->bank_id;
command_access->u.write.column_id = column_id;
}
list_add(info->command_queue, command_precharge);
list_add(info->command_queue, command_activate);
list_add(info->command_queue, command_access);
/* Update the active row status */
info->active_row_id = row_id;
}
/* Row miss - no row was activated */
else
{
/* Create act, rd/wr two commands */
command_activate = dram_command_create();
command_access = dram_command_create();
/* Activate */
command_activate->type = dram_command_activate;
command_activate->dram = list_get(controller->dram_list, info->channel_id);
command_activate->u.activate.rank_id = info->rank_id;
command_activate->u.activate.bank_id = info->bank_id;
command_activate->u.activate.row_id = row_id;
/* Access */
command_access->dram = list_get(controller->dram_list, info->channel_id);
if (request->type == request_type_read)
{
command_access->type = dram_command_read;
command_access->u.read.rank_id = info->rank_id;
command_access->u.read.bank_id = info->bank_id;
command_access->u.read.column_id = column_id;
}
else if (request->type == request_type_write)
{
command_access->type = dram_command_write;
command_access->u.write.rank_id = info->rank_id;
command_access->u.write.bank_id = info->bank_id;
command_access->u.write.column_id = column_id;
}
list_add(info->command_queue, command_activate);
list_add(info->command_queue, command_access);
/* Update the active row status */
info->row_buffer_valid = 1;
info->active_row_id = row_id;
}
break;
/* Close page row buffer policy */
case close_page_row_buffer_policy:
/* Create act, rd/wr, pre three commands */
command_activate = dram_command_create();
command_access = dram_command_create();
command_precharge = dram_command_create();
/* Activate */
command_activate->type = dram_command_activate;
command_activate->dram = list_get(controller->dram_list, info->channel_id);
command_activate->u.activate.rank_id = info->rank_id;
command_activate->u.activate.bank_id = info->bank_id;
command_activate->u.activate.row_id = row_id;
/* Access */
command_access->dram = list_get(controller->dram_list, info->channel_id);
if (request->type == request_type_read)
{
command_access->type = dram_command_read;
command_access->u.read.rank_id = info->rank_id;
command_access->u.read.bank_id = info->bank_id;
command_access->u.read.column_id = column_id;
}
else if (request->type == request_type_write)
{
command_access->type = dram_command_write;
command_access->u.write.rank_id = info->rank_id;
command_access->u.write.bank_id = info->bank_id;
command_access->u.write.column_id = column_id;
}
/* Precharge */
command_precharge->type = dram_command_precharge;
command_precharge->dram = list_get(controller->dram_list, info->channel_id);
command_precharge->u.precharge.rank_id = info->rank_id;
command_precharge->u.precharge.bank_id = info->bank_id;
list_add(info->command_queue, command_activate);
list_add(info->command_queue, command_access);
list_add(info->command_queue, command_precharge);
/* Update the active row status */
info->row_buffer_valid = 0;
break;
case hybird_page_row_buffer_policy:
break;
default:
break;
}
dram_request_free(request);
}
}
}
