1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2020 Intel Corporation 4 */ 5 6 #include "i915_drv.h" 7 #include "i915_reg.h" 8 #include "intel_gt.h" 9 #include "intel_gt_clock_utils.h" 10 #include "intel_gt_regs.h" 11 12 static u32 read_reference_ts_freq(struct intel_uncore *uncore) 13 { 14 u32 ts_override = intel_uncore_read(uncore, GEN9_TIMESTAMP_OVERRIDE); 15 u32 base_freq, frac_freq; 16 17 base_freq = ((ts_override & GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DIVIDER_MASK) >> 18 GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DIVIDER_SHIFT) + 1; 19 base_freq *= 1000000; 20 21 frac_freq = ((ts_override & 22 GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_MASK) >> 23 GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_SHIFT); 24 frac_freq = 1000000 / (frac_freq + 1); 25 26 return base_freq + frac_freq; 27 } 28 29 static u32 gen11_get_crystal_clock_freq(struct intel_uncore *uncore, 30 u32 rpm_config_reg) 31 { 32 u32 f19_2_mhz = 19200000; 33 u32 f24_mhz = 24000000; 34 u32 f25_mhz = 25000000; 35 u32 f38_4_mhz = 38400000; 36 u32 crystal_clock = 37 (rpm_config_reg & GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK) >> 38 GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT; 39 40 switch (crystal_clock) { 41 case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ: 42 return f24_mhz; 43 case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ: 44 return f19_2_mhz; 45 case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_38_4_MHZ: 46 return f38_4_mhz; 47 case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_25_MHZ: 48 return f25_mhz; 49 default: 50 MISSING_CASE(crystal_clock); 51 return 0; 52 } 53 } 54 55 static u32 gen11_read_clock_frequency(struct intel_uncore *uncore) 56 { 57 u32 ctc_reg = intel_uncore_read(uncore, CTC_MODE); 58 u32 freq = 0; 59 60 /* 61 * Note that on gen11+, the clock frequency may be reconfigured. 62 * We do not, and we assume nobody else does. 63 * 64 * First figure out the reference frequency. There are 2 ways 65 * we can compute the frequency, either through the 66 * TIMESTAMP_OVERRIDE register or through RPM_CONFIG. CTC_MODE 67 * tells us which one we should use. 68 */ 69 if ((ctc_reg & CTC_SOURCE_PARAMETER_MASK) == CTC_SOURCE_DIVIDE_LOGIC) { 70 freq = read_reference_ts_freq(uncore); 71 } else { 72 u32 c0 = intel_uncore_read(uncore, RPM_CONFIG0); 73 74 freq = gen11_get_crystal_clock_freq(uncore, c0); 75 76 /* 77 * Now figure out how the command stream's timestamp 78 * register increments from this frequency (it might 79 * increment only every few clock cycle). 80 */ 81 freq >>= 3 - ((c0 & GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_MASK) >> 82 GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT); 83 } 84 85 return freq; 86 } 87 88 static u32 gen9_read_clock_frequency(struct intel_uncore *uncore) 89 { 90 u32 ctc_reg = intel_uncore_read(uncore, CTC_MODE); 91 u32 freq = 0; 92 93 if ((ctc_reg & CTC_SOURCE_PARAMETER_MASK) == CTC_SOURCE_DIVIDE_LOGIC) { 94 freq = read_reference_ts_freq(uncore); 95 } else { 96 freq = IS_GEN9_LP(uncore->i915) ? 19200000 : 24000000; 97 98 /* 99 * Now figure out how the command stream's timestamp 100 * register increments from this frequency (it might 101 * increment only every few clock cycle). 102 */ 103 freq >>= 3 - ((ctc_reg & CTC_SHIFT_PARAMETER_MASK) >> 104 CTC_SHIFT_PARAMETER_SHIFT); 105 } 106 107 return freq; 108 } 109 110 static u32 gen5_read_clock_frequency(struct intel_uncore *uncore) 111 { 112 /* 113 * PRMs say: 114 * 115 * "The PCU TSC counts 10ns increments; this timestamp 116 * reflects bits 38:3 of the TSC (i.e. 80ns granularity, 117 * rolling over every 1.5 hours). 118 */ 119 return 12500000; 120 } 121 122 static u32 gen2_read_clock_frequency(struct intel_uncore *uncore) 123 { 124 /* 125 * PRMs say: 126 * 127 * "The value in this register increments once every 16 128 * hclks." (through the “Clocking Configuration” 129 * (“CLKCFG”) MCHBAR register) 130 */ 131 return RUNTIME_INFO(uncore->i915)->rawclk_freq * 1000 / 16; 132 } 133 134 static u32 read_clock_frequency(struct intel_uncore *uncore) 135 { 136 if (GRAPHICS_VER(uncore->i915) >= 11) 137 return gen11_read_clock_frequency(uncore); 138 else if (GRAPHICS_VER(uncore->i915) >= 9) 139 return gen9_read_clock_frequency(uncore); 140 else if (GRAPHICS_VER(uncore->i915) >= 5) 141 return gen5_read_clock_frequency(uncore); 142 else 143 return gen2_read_clock_frequency(uncore); 144 } 145 146 void intel_gt_init_clock_frequency(struct intel_gt *gt) 147 { 148 gt->clock_frequency = read_clock_frequency(gt->uncore); 149 150 /* Icelake appears to use another fixed frequency for CTX_TIMESTAMP */ 151 if (GRAPHICS_VER(gt->i915) == 11) 152 gt->clock_period_ns = NSEC_PER_SEC / 13750000; 153 else if (gt->clock_frequency) 154 gt->clock_period_ns = intel_gt_clock_interval_to_ns(gt, 1); 155 156 GT_TRACE(gt, 157 "Using clock frequency: %dkHz, period: %dns, wrap: %lldms\n", 158 gt->clock_frequency / 1000, 159 gt->clock_period_ns, 160 div_u64(mul_u32_u32(gt->clock_period_ns, S32_MAX), 161 USEC_PER_SEC)); 162 } 163 164 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM) 165 void intel_gt_check_clock_frequency(const struct intel_gt *gt) 166 { 167 if (gt->clock_frequency != read_clock_frequency(gt->uncore)) { 168 dev_err(gt->i915->drm.dev, 169 "GT clock frequency changed, was %uHz, now %uHz!\n", 170 gt->clock_frequency, 171 read_clock_frequency(gt->uncore)); 172 } 173 } 174 #endif 175 176 static u64 div_u64_roundup(u64 nom, u32 den) 177 { 178 return div_u64(nom + den - 1, den); 179 } 180 181 u64 intel_gt_clock_interval_to_ns(const struct intel_gt *gt, u64 count) 182 { 183 return div_u64_roundup(count * NSEC_PER_SEC, gt->clock_frequency); 184 } 185 186 u64 intel_gt_pm_interval_to_ns(const struct intel_gt *gt, u64 count) 187 { 188 return intel_gt_clock_interval_to_ns(gt, 16 * count); 189 } 190 191 u64 intel_gt_ns_to_clock_interval(const struct intel_gt *gt, u64 ns) 192 { 193 return div_u64_roundup(gt->clock_frequency * ns, NSEC_PER_SEC); 194 } 195 196 u64 intel_gt_ns_to_pm_interval(const struct intel_gt *gt, u64 ns) 197 { 198 u64 val; 199 200 /* 201 * Make these a multiple of magic 25 to avoid SNB (eg. Dell XPS 202 * 8300) freezing up around GPU hangs. Looks as if even 203 * scheduling/timer interrupts start misbehaving if the RPS 204 * EI/thresholds are "bad", leading to a very sluggish or even 205 * frozen machine. 206 */ 207 val = div_u64_roundup(intel_gt_ns_to_clock_interval(gt, ns), 16); 208 if (GRAPHICS_VER(gt->i915) == 6) 209 val = div_u64_roundup(val, 25) * 25; 210 211 return val; 212 } 213