power_spec.h

 
#ifndef BACKENDS_TOFINO_BF_P4C_MAU_POWER_SPEC_H_
#define BACKENDS_TOFINO_BF_P4C_MAU_POWER_SPEC_H_
 
class MauPowerSpec {
 public:
    MauPowerSpec() {}
 
    virtual double get_max_power() const = 0;  // Value for all pipes.
    virtual double get_excess_power_threshold() const = 0;
    virtual double get_absolute_max_power_threshold() const = 0;
 
    virtual double get_ram_scaling_factor() const = 0;
    virtual double get_tcam_scaling_factor() const = 0;
    virtual double get_voltage_scaling_factor() const = 0;
    virtual double get_ram_read_power() const = 0;
    virtual double get_ram_write_power() const = 0;
    virtual double get_tcam_search_power() const = 0;
    virtual double get_map_ram_read_power() const = 0;
    virtual double get_map_ram_write_power() const = 0;
    virtual double get_deferred_ram_read_power() const = 0;
    virtual double get_deferred_ram_write_power() const = 0;
 
    virtual int get_base_delay() const { return 20; }
    virtual int get_base_predication_delay() const { return 11; }
    virtual int get_tcam_delay() const { return 2; }
    virtual int get_selector_delay() const { return 8; }
    virtual int get_meter_lpf_delay() const { return 4; }
    virtual int get_stateful_delay() const { return 4; }
    virtual int get_mau_corner_turn_delay() const = 0;
 
    virtual int get_concurrent_latency_contribution() const = 0;
    virtual int get_action_latency_contribution() const { return 2; }
 
    virtual int get_min_required_egress_mau_latency() const = 0;
 
    virtual int get_deparser_throughput_scaling_starts() const = 0;
    virtual int get_deparser_max_phv_valid() const = 0;
    virtual int get_cycles_to_issue_credit_to_pmarb() const = 0;
    virtual int get_pmarb_cycles_from_receive_credit_to_issue_phv_to_mau() const = 0;
};
 
class TofinoMauPowerSpec : public MauPowerSpec {
 public:
    TofinoMauPowerSpec() {}
 
    double get_max_power() const override { return 40.0; }
    double get_excess_power_threshold() const override { return 10.0; }
    double get_absolute_max_power_threshold() const override { return 22.0; }
 
    double get_ram_scaling_factor() const override {
        return 1.88574 * get_voltage_scaling_factor();
    }
    double get_tcam_scaling_factor() const override {
        return 0.62736 * get_voltage_scaling_factor();
    }
    double get_voltage_scaling_factor() const override { return 1.0; }
 
    // Power nos are for 1.27 GHz PPS (Clock freq of MAU)
    double get_ram_read_power() const override { return 0.012771 * get_ram_scaling_factor(); }
    double get_ram_write_power() const override { return 0.023419 * get_ram_scaling_factor(); }
    double get_tcam_search_power() const override { return 0.0398 * get_tcam_scaling_factor(); }
    double get_map_ram_read_power() const override { return 0.0025861 * get_ram_scaling_factor(); }
    double get_map_ram_write_power() const override { return 0.0030107 * get_ram_scaling_factor(); }
    double get_deferred_ram_read_power() const override {
        return 0.0029238 * get_ram_scaling_factor();
    }
    double get_deferred_ram_write_power() const override {
        return 0.0020185 * get_ram_scaling_factor();
    }
 
    int get_mau_corner_turn_delay() const override { return 4; }
    int get_concurrent_latency_contribution() const override { return 1; }
    int get_min_required_egress_mau_latency() const override { return 160; }
 
    // For scaling MAU power based on deparser throttling.
    int get_deparser_throughput_scaling_starts() const override {
        return get_deparser_max_phv_valid() - get_cycles_to_issue_credit_to_pmarb() -
               get_pmarb_cycles_from_receive_credit_to_issue_phv_to_mau();
    }
    int get_deparser_max_phv_valid() const override { return 288; }
    int get_cycles_to_issue_credit_to_pmarb() const override { return 28; }
    int get_pmarb_cycles_from_receive_credit_to_issue_phv_to_mau() const override { return 11; }
};
 
class JBayMauPowerSpec : public MauPowerSpec {
 public:
    JBayMauPowerSpec() {}
 
    double get_max_power() const override { return 52.0; }
    double get_excess_power_threshold() const override { return 10.0; }
    double get_absolute_max_power_threshold() const override { return 10.0; }
 
    double get_ram_scaling_factor() const override { return 1.0 * get_voltage_scaling_factor(); }
    double get_tcam_scaling_factor() const override { return 1.0 * get_voltage_scaling_factor(); }
    double get_voltage_scaling_factor() const override {
        // The voltage the unit memory numbers are derived from.
        double measured_voltage = 0.750;  // in Volts
        // TODO: Pass in a voltage as command line argument, and sanity check.
        double user_voltage = 0.750;  // in Volts
        // Power consumption scales with difference in voltage from measured as:
        // (V_user / V_meas)^2
        return (user_voltage / measured_voltage) * (user_voltage / measured_voltage);
    }
 
    // Power nos are for 1.5 GHz PPS (Clock freq of MAU)
    double get_ram_read_power() const override { return 0.0166 * get_ram_scaling_factor(); }
    double get_ram_write_power() const override { return 0.0176 * get_ram_scaling_factor(); }
    double get_tcam_search_power() const override { return 0.0185 * get_tcam_scaling_factor(); }
    double get_map_ram_read_power() const override { return 0.0027 * get_ram_scaling_factor(); }
    double get_map_ram_write_power() const override { return 0.0030 * get_ram_scaling_factor(); }
    double get_deferred_ram_read_power() const override {
        return 0.0025 * get_ram_scaling_factor();
    }
    double get_deferred_ram_write_power() const override {
        return 0.0024 * get_ram_scaling_factor();
    }
 
    int get_mau_corner_turn_delay() const override { return 0; }
 
    int get_concurrent_latency_contribution() const override {
        return get_action_latency_contribution();
    }
 
    int get_min_required_egress_mau_latency() const override { return 0; }
 
    int get_deparser_throughput_scaling_starts() const override { return 600; }
 
    int get_deparser_max_phv_valid() const override { return 0; }
    int get_cycles_to_issue_credit_to_pmarb() const override { return 0; }
    int get_pmarb_cycles_from_receive_credit_to_issue_phv_to_mau() const override { return 0; }
};
 
#if BAREFOOT_INTERNAL
class JBayHMauPowerSpec : public JBayMauPowerSpec {
 public:
    JBayHMauPowerSpec() {}
    double get_max_power() const override { return 15.6; }  // scaled by stages
};
#endif /* BAREFOOT_INTERNAL */
 
class JBayMMauPowerSpec : public JBayMauPowerSpec {
 public:
    JBayMMauPowerSpec() {}
    double get_max_power() const override { return 31.2; }  // scaled by stages
};
 
class JBayUMauPowerSpec : public JBayMauPowerSpec {
 public:
    JBayUMauPowerSpec() {}
};
 
#endif /* BACKENDS_TOFINO_BF_P4C_MAU_POWER_SPEC_H_ */