diff options
Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_llc.c')
| -rw-r--r-- | drivers/gpu/drm/i915/gt/intel_llc.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_llc.c b/drivers/gpu/drm/i915/gt/intel_llc.c new file mode 100644 index 000000000000..ceb785b75c25 --- /dev/null +++ b/drivers/gpu/drm/i915/gt/intel_llc.c @@ -0,0 +1,161 @@ +/* + * SPDX-License-Identifier: MIT + * + * Copyright © 2019 Intel Corporation + */ + +#include <linux/cpufreq.h> + +#include "i915_drv.h" +#include "intel_gt.h" +#include "intel_llc.h" +#include "intel_sideband.h" + +struct ia_constants { + unsigned int min_gpu_freq; + unsigned int max_gpu_freq; + + unsigned int min_ring_freq; + unsigned int max_ia_freq; +}; + +static struct intel_gt *llc_to_gt(struct intel_llc *llc) +{ + return container_of(llc, struct intel_gt, llc); +} + +static unsigned int cpu_max_MHz(void) +{ + struct cpufreq_policy *policy; + unsigned int max_khz; + + policy = cpufreq_cpu_get(0); + if (policy) { + max_khz = policy->cpuinfo.max_freq; + cpufreq_cpu_put(policy); + } else { + /* + * Default to measured freq if none found, PCU will ensure we + * don't go over + */ + max_khz = tsc_khz; + } + + return max_khz / 1000; +} + +static bool get_ia_constants(struct intel_llc *llc, + struct ia_constants *consts) +{ + struct drm_i915_private *i915 = llc_to_gt(llc)->i915; + struct intel_rps *rps = &llc_to_gt(llc)->rps; + + if (rps->max_freq <= rps->min_freq) + return false; + + consts->max_ia_freq = cpu_max_MHz(); + + consts->min_ring_freq = + intel_uncore_read(llc_to_gt(llc)->uncore, DCLK) & 0xf; + /* convert DDR frequency from units of 266.6MHz to bandwidth */ + consts->min_ring_freq = mult_frac(consts->min_ring_freq, 8, 3); + + consts->min_gpu_freq = rps->min_freq; + consts->max_gpu_freq = rps->max_freq; + if (INTEL_GEN(i915) >= 9) { + /* Convert GT frequency to 50 HZ units */ + consts->min_gpu_freq /= GEN9_FREQ_SCALER; + consts->max_gpu_freq /= GEN9_FREQ_SCALER; + } + + return true; +} + +static void calc_ia_freq(struct intel_llc *llc, + unsigned int gpu_freq, + const struct ia_constants *consts, + unsigned int *out_ia_freq, + unsigned int *out_ring_freq) +{ + struct drm_i915_private *i915 = llc_to_gt(llc)->i915; + const int diff = consts->max_gpu_freq - gpu_freq; + unsigned int ia_freq = 0, ring_freq = 0; + + if (INTEL_GEN(i915) >= 9) { + /* + * ring_freq = 2 * GT. ring_freq is in 100MHz units + * No floor required for ring frequency on SKL. + */ + ring_freq = gpu_freq; + } else if (INTEL_GEN(i915) >= 8) { + /* max(2 * GT, DDR). NB: GT is 50MHz units */ + ring_freq = max(consts->min_ring_freq, gpu_freq); + } else if (IS_HASWELL(i915)) { + ring_freq = mult_frac(gpu_freq, 5, 4); + ring_freq = max(consts->min_ring_freq, ring_freq); + /* leave ia_freq as the default, chosen by cpufreq */ + } else { + const int min_freq = 15; + const int scale = 180; + + /* + * On older processors, there is no separate ring + * clock domain, so in order to boost the bandwidth + * of the ring, we need to upclock the CPU (ia_freq). + * + * For GPU frequencies less than 750MHz, + * just use the lowest ring freq. + */ + if (gpu_freq < min_freq) + ia_freq = 800; + else + ia_freq = consts->max_ia_freq - diff * scale / 2; + ia_freq = DIV_ROUND_CLOSEST(ia_freq, 100); + } + + *out_ia_freq = ia_freq; + *out_ring_freq = ring_freq; +} + +static void gen6_update_ring_freq(struct intel_llc *llc) +{ + struct drm_i915_private *i915 = llc_to_gt(llc)->i915; + struct ia_constants consts; + unsigned int gpu_freq; + + if (!get_ia_constants(llc, &consts)) + return; + + /* + * For each potential GPU frequency, load a ring frequency we'd like + * to use for memory access. We do this by specifying the IA frequency + * the PCU should use as a reference to determine the ring frequency. + */ + for (gpu_freq = consts.max_gpu_freq; + gpu_freq >= consts.min_gpu_freq; + gpu_freq--) { + unsigned int ia_freq, ring_freq; + + calc_ia_freq(llc, gpu_freq, &consts, &ia_freq, &ring_freq); + sandybridge_pcode_write(i915, + GEN6_PCODE_WRITE_MIN_FREQ_TABLE, + ia_freq << GEN6_PCODE_FREQ_IA_RATIO_SHIFT | + ring_freq << GEN6_PCODE_FREQ_RING_RATIO_SHIFT | + gpu_freq); + } +} + +void intel_llc_enable(struct intel_llc *llc) +{ + if (HAS_LLC(llc_to_gt(llc)->i915)) + gen6_update_ring_freq(llc); +} + +void intel_llc_disable(struct intel_llc *llc) +{ + /* Currently there is no HW configuration to be done to disable. */ +} + +#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST) +#include "selftest_llc.c" +#endif |