sc53c94: implement sequencer and some commands.

This commit is contained in:
Maxim Poliakovski 2022-02-05 18:17:17 +01:00
parent 2edb50a821
commit 7c53620a40
2 changed files with 234 additions and 16 deletions

View File

@ -21,27 +21,46 @@ along with this program. If not, see <https://www.gnu.org/licenses/>.
/** @file NCR53C94/Am53CF94 SCSI controller emulation. */
#include "sc53c94.h"
#include <core/timermanager.h>
#include <devices/common/hwcomponent.h>
#include <devices/common/scsi/sc53c94.h>
#include <loguru.hpp>
#include <machines/machinebase.h>
#include <cinttypes>
Sc53C94::Sc53C94(uint8_t chip_id)
Sc53C94::Sc53C94(uint8_t chip_id, uint8_t my_id)
{
this->chip_id = chip_id;
this->chip_id = chip_id;
this->my_bus_id = my_id;
supports_types(HWCompType::SCSI_HOST | HWCompType::SCSI_DEV);
reset_device();
}
int Sc53C94::device_postinit()
{
this->bus_obj = dynamic_cast<ScsiBus*>(gMachineObj->get_comp_by_name("SCSI0"));
this->bus_obj->register_device(7, static_cast<ScsiDevice*>(this));
return 0;
}
void Sc53C94::reset_device()
{
// part-unique ID to be read using a magic sequence
this->set_xfer_count = this->chip_id << 16;
this->clk_factor = 2;
this->sel_timeout = 0;
this->clk_factor = 2;
this->sel_timeout = 0;
this->is_initiator = true;
// clear command FIFO
this->cmd_fifo_pos = 0;
// clear data FIFO
this->data_fifo_pos = 0;
this->data_fifo[0] = 0;
this->seq_step = 0;
}
uint8_t Sc53C94::read(uint8_t reg_offset)
@ -70,13 +89,25 @@ void Sc53C94::write(uint8_t reg_offset, uint8_t value)
case Write::Reg53C94::Command:
update_command_reg(value);
break;
case Write::Reg53C94::FIFO:
fifo_push(value);
break;
case Write::Reg53C94::Dest_Bus_ID:
this->target_id = value & 7;
break;
case Write::Reg53C94::Sel_Timeout:
this->sel_timeout = value;
break;
case Write::Reg53C94::Sync_Offset:
this->sync_offset = value;
break;
case Write::Reg53C94::Clock_Factor:
this->clk_factor = value;
break;
case Write::Reg53C94::Config_1:
if ((value & 7) != this->my_bus_id) {
ABORT_F("SC53C94: HBA bus ID mismatch!");
}
this->config1 = value;
break;
case Write::Reg53C94::Config_2:
@ -131,6 +162,9 @@ void Sc53C94::exec_command()
}
}
// simple commands will be executed immediately
// complex commands will be broken into multiple steps
// and handled by the sequencer
switch (cmd) {
case CMD_NOP:
this->on_reset = false; // unblock the command register
@ -147,12 +181,36 @@ void Sc53C94::exec_command()
return;
case CMD_RESET_BUS:
LOG_F(INFO, "SC53C94: resetting SCSI bus...");
// assert RST line
this->bus_obj->assert_ctrl_line(this->my_bus_id, SCSI_CTRL_RST);
// release RST line after 25 us
my_timer_id = TimerManager::get_instance()->add_oneshot_timer(
USECS_TO_NSECS(25),
[this]() {
this->bus_obj->release_ctrl_line(this->my_bus_id, SCSI_CTRL_RST);
});
if (!(config1 & 0x40)) {
LOG_F(INFO, "SC53C94: reset interrupt issued");
this->int_status |= INTSTAT_SRST;
}
exec_next_command();
break;
case CMD_SELECT_NO_ATN:
static SeqDesc sel_no_atn_desc[] {
{SeqState::SEL_BEGIN, 2, INTSTAT_SR | INTSTAT_SO},
{SeqState::CMD_BEGIN, 3, INTSTAT_SR | INTSTAT_SO},
{SeqState::CMD_COMPLETE, 4, INTSTAT_SR | INTSTAT_SO},
};
this->seq_step = 0;
this->cmd_steps = sel_no_atn_desc;
this->cur_state = SeqState::BUS_FREE;
sequencer();
LOG_F(INFO, "SC53C94: SELECT W/O ATN command started");
break;
default:
LOG_F(ERROR, "SC53C94: invalid/unimplemented command 0x%X", cmd);
this->cmd_fifo_pos--; // remove invalid command from FIFO
this->int_status |= 0x40; // set ICMD bit
this->int_status |= INTSTAT_ICMD;
}
}
@ -166,3 +224,102 @@ void Sc53C94::exec_next_command()
}
}
}
void Sc53C94::fifo_push(const uint8_t data)
{
if (this->data_fifo_pos < 16) {
this->data_fifo[this->data_fifo_pos++] = data;
} else {
LOG_F(ERROR, "SC53C94: data FIFO overflow!");
this->status |= 0x40; // signal IOE/Gross Error
}
}
void Sc53C94::seq_defer_state(uint64_t delay_ns)
{
seq_timer_id = TimerManager::get_instance()->add_oneshot_timer(
delay_ns,
[this]() {
// re-enter the sequencer with the state specified in next_state
this->cur_state = this->next_state;
this->sequencer();
});
}
void Sc53C94::sequencer()
{
switch (this->cur_state) {
case SeqState::IDLE:
break;
case SeqState::BUS_FREE:
if (this->bus_obj->current_phase() == ScsiPhase::BUS_FREE) {
this->next_state = SeqState::ARB_BEGIN;
this->seq_defer_state(BUS_FREE_DELAY + BUS_SETTLE_DELAY);
} else { // continue waiting
this->next_state = SeqState::BUS_FREE;
this->seq_defer_state(BUS_FREE_DELAY);
}
break;
case SeqState::ARB_BEGIN:
if (!this->bus_obj->begin_arbitration(this->my_bus_id)) {
LOG_F(ERROR, "SC53C94: arbitration error, bus not free!");
this->bus_obj->release_ctrl_lines(this->my_bus_id);
this->next_state = SeqState::BUS_FREE;
this->seq_defer_state(BUS_CLEAR_DELAY);
break;
}
this->next_state = SeqState::ARB_END;
this->seq_defer_state(ARB_DELAY);
break;
case SeqState::ARB_END:
if (this->bus_obj->end_arbitration(this->my_bus_id)) { // arbitration won
this->next_state = this->cmd_steps->next_step;
this->seq_defer_state(BUS_CLEAR_DELAY + BUS_SETTLE_DELAY);
} else { // arbitration lost
LOG_F(INFO, "SC53C94: arbitration lost!");
this->bus_obj->release_ctrl_lines(this->my_bus_id);
this->next_state = SeqState::BUS_FREE;
this->seq_defer_state(BUS_CLEAR_DELAY);
}
break;
case SeqState::SEL_BEGIN:
this->is_initiator = true;
this->bus_obj->begin_selection(this->my_bus_id, this->target_id,
this->cur_cmd != CMD_SELECT_NO_ATN);
this->next_state = SeqState::SEL_END;
this->seq_defer_state(SEL_TIME_OUT);
break;
case SeqState::SEL_END:
if (this->bus_obj->end_selection(this->my_bus_id, this->target_id)) {
LOG_F(INFO, "SC53C94: selection completed");
this->cmd_steps++;
} else { // selection timeout
this->seq_step = this->cmd_steps->step_num;
this->int_status |= this->cmd_steps->status;
this->bus_obj->release_ctrl_lines(this->my_bus_id);
this->cur_state = SeqState::IDLE;
exec_next_command();
}
break;
default:
ABORT_F("SC53C94: unimplemented sequencer state %d", this->cur_state);
}
}
void Sc53C94::notify(ScsiMsg msg_type, int param)
{
switch (msg_type) {
case ScsiMsg::CONFIRM_SEL:
if (this->target_id == param) {
// cancel selection timeout timer
TimerManager::get_instance()->cancel_timer(this->seq_timer_id);
this->cur_state = SeqState::SEL_END;
sequencer();
} else {
LOG_F(WARNING, "SC53C94: ignore invalid selection confirmation message");
}
break;
default:
LOG_F(WARNING, "SC53C94: ignore notification message, type: %d", msg_type);
}
}

View File

@ -29,6 +29,8 @@ along with this program. If not, see <https://www.gnu.org/licenses/>.
#ifndef SC_53C94_H
#define SC_53C94_H
#include "scsi.h"
#include <cinttypes>
/** 53C94 read registers */
@ -59,8 +61,8 @@ namespace Write {
Command = 3,
Dest_Bus_ID = 4,
Sel_Timeout = 5,
Synch_Period = 6,
Synch_Offset = 7,
Sync_Period = 6,
Sync_Offset = 7,
Config_1 = 8,
Clock_Factor = 9,
Test_Mode = 0xA,
@ -74,34 +76,82 @@ namespace Write {
/** NCR53C94/Am53CF94 commands. */
enum {
CMD_NOP = 0,
CMD_CLEAR_FIFO = 1,
CMD_RESET_DEVICE = 2,
CMD_RESET_BUS = 3,
CMD_DMA_STOP = 4,
CMD_NOP = 0,
CMD_CLEAR_FIFO = 1,
CMD_RESET_DEVICE = 2,
CMD_RESET_BUS = 3,
CMD_DMA_STOP = 4,
CMD_SELECT_NO_ATN = 0x41,
};
/** Interrupt status register bits. */
enum {
INTSTAT_SRST = 0x80, // bus reset
INTSTAT_ICMD = 0x40, // invalid command
INTSTAT_DIS = 0x20, // disconnected
INTSTAT_SR = 0x10, // service request
INTSTAT_SO = 0x08, // successful operation
INTSTAT_RESEL = 0x04, // reselected
INTSTAT_SELA = 0x02, // selected as a target with attention
INTSTAT_SEL = 0x01, // selected as a target without attention
};
enum {
CFG2_ENF = 0x40, // Am53CF94: enable features (ENF) bit
CFG2_ENF = 0x40, // Am53CF94: enable features (ENF) bit
};
class Sc53C94 {
/** Sequencer states. */
namespace SeqState {
enum {
IDLE = 0,
BUS_FREE,
ARB_BEGIN,
ARB_END,
SEL_BEGIN,
SEL_END,
CMD_BEGIN,
CMD_COMPLETE,
};
};
/** Sequence descriptor for sequencer commands. */
typedef struct {
int next_step;
int step_num;
int status;
} SeqDesc;
class Sc53C94 : public ScsiDevice {
public:
Sc53C94(uint8_t chip_id=12);
Sc53C94(uint8_t chip_id=12, uint8_t my_id=7);
~Sc53C94() = default;
// HWComponent methods
int device_postinit();
// 53C94 registers access
uint8_t read(uint8_t reg_offset);
void write(uint8_t reg_offset, uint8_t value);
// ScsiDevice methods
void notify(ScsiMsg msg_type, int param);
protected:
void reset_device();
void update_command_reg(uint8_t cmd);
void exec_command();
void exec_next_command();
void fifo_push(const uint8_t data);
void sequencer();
void seq_defer_state(uint64_t delay_ns);
private:
uint8_t chip_id;
uint8_t my_bus_id;
ScsiBus* bus_obj;
uint32_t my_timer_id;
uint8_t cmd_fifo[2];
uint8_t data_fifo[16];
int cmd_fifo_pos;
@ -110,12 +160,23 @@ private:
uint32_t xfer_count;
uint32_t set_xfer_count;
uint8_t status;
uint8_t target_id;
uint8_t int_status;
uint8_t seq_step;
uint8_t sel_timeout;
uint8_t sync_offset;
uint8_t clk_factor;
uint8_t config1;
uint8_t config2;
uint8_t config3;
// sequencer state
uint32_t seq_timer_id;
uint32_t cur_state;
uint32_t next_state;
SeqDesc* cmd_steps;
bool is_initiator;
uint8_t cur_cmd;
};
#endif // SC_53C94_H