// SPDX-License-Identifier: MIT
/*
* Copyright © 2020 Intel Corporation
*/
#include "i915_drv.h"
#include "i915_reg.h"
#include "intel_gt.h"
#include "intel_gt_clock_utils.h"
#include "intel_gt_print.h"
#include "intel_gt_regs.h"
#include "soc/intel_dram.h"
static u32 read_reference_ts_freq(struct intel_uncore *uncore)
{
u32 ts_override = intel_uncore_read(uncore, GEN9_TIMESTAMP_OVERRIDE);
u32 base_freq, frac_freq;
base_freq = ((ts_override & GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DIVIDER_MASK) >>
GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DIVIDER_SHIFT) + 1;
base_freq *= 1000000;
frac_freq = ((ts_override &
GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_MASK) >>
GEN9_TIMESTAMP_OVERRIDE_US_COUNTER_DENOMINATOR_SHIFT);
frac_freq = 1000000 / (frac_freq + 1);
return base_freq + frac_freq;
}
static u32 gen11_get_crystal_clock_freq(struct intel_uncore *uncore,
u32 rpm_config_reg)
{
u32 f19_2_mhz = 19200000;
u32 f24_mhz = 24000000;
u32 f25_mhz = 25000000;
u32 f38_4_mhz = 38400000;
u32 crystal_clock =
(rpm_config_reg & GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_MASK) >>
GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_SHIFT;
switch (crystal_clock) {
case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_24_MHZ:
return f24_mhz;
case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_19_2_MHZ:
return f19_2_mhz;
case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_38_4_MHZ:
return f38_4_mhz;
case GEN11_RPM_CONFIG0_CRYSTAL_CLOCK_FREQ_25_MHZ:
return f25_mhz;
default:
MISSING_CASE(crystal_clock);
return 0;
}
}
static u32 gen11_read_clock_frequency(struct intel_uncore *uncore)
{
u32 ctc_reg = intel_uncore_read(uncore, CTC_MODE);
u32 freq = 0;
/*
* Note that on gen11+, the clock frequency may be reconfigured.
* We do not, and we assume nobody else does.
*
* First figure out the reference frequency. There are 2 ways
* we can compute the frequency, either through the
* TIMESTAMP_OVERRIDE register or through RPM_CONFIG. CTC_MODE
* tells us which one we should use.
*/
if ((ctc_reg & CTC_SOURCE_PARAMETER_MASK) == CTC_SOURCE_DIVIDE_LOGIC) {
freq = read_reference_ts_freq(uncore);
} else {
u32 c0 = intel_uncore_read(uncore, RPM_CONFIG0);
freq = gen11_get_crystal_clock_freq(uncore, c0);
/*
* Now figure out how the command stream's timestamp
* register increments from this frequency (it might
* increment only every few clock cycle).
*/
freq >>= 3 - ((c0 & GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_MASK) >>
GEN10_RPM_CONFIG0_CTC_SHIFT_PARAMETER_SHIFT);
}
return freq;
}
static u32 gen9_read_clock_frequency(struct intel_uncore *uncore)
{
u32 ctc_reg = intel_uncore_read(uncore, CTC_MODE);
u32 freq = 0;
if ((ctc_reg & CTC_SOURCE_PARAMETER_MASK) == CTC_SOURCE_DIVIDE_LOGIC) {
freq = read_reference_ts_freq(uncore);
} else {
freq = IS_GEN9_LP(uncore->i915) ? 19200000 : 24000000;
/*
* Now figure out how the command stream's timestamp
* register increments from this frequency (it might
* increment only every few clock cycle).
*/
freq >>= 3 - ((ctc_reg & CTC_SHIFT_PARAMETER_MASK) >>
CTC_SHIFT_PARAMETER_SHIFT);
}
return freq;
}
static u32 gen6_read_clock_frequency(struct intel_uncore *uncore)
{
/*
* PRMs say:
*
* "The PCU TSC counts 10ns increments; this timestamp
* reflects bits 38:3 of the TSC (i.e. 80ns granularity,
* rolling over every 1.5 hours).
*/
return 12500000;
}
static u32 gen5_read_clock_frequency(struct intel_uncore *uncore)
{
/*
* 63:32 increments every 1000 ns
* 31:0 mbz
*/
return 1000000000 / 1000;
}
static u32 g4x_read_clock_frequency(struct intel_uncore *uncore)
{
/*
* 63:20 increments every 1/4 ns
* 19:0 mbz
*
* -> 63:32 increments every 1024 ns
*/
return 1000000000 / 1024;
}
static u32 gen4_read_clock_frequency(struct intel_uncore *uncore)
{
/*
* PRMs say:
*
* "The value in this register increments once every 16
* hclks." (through the “Clocking Configuration”
* (“CLKCFG”) MCHBAR register)
*
* Testing on actual hardware has shown there is no /16.
*/
return DIV_ROUND_CLOSEST(i9xx_fsb_freq(uncore->i915), 4) * 1000;
}
static u32 read_clock_frequency(struct intel_uncore *uncore)
{
if (GRAPHICS_VER(uncore->i915) >= 11)
return gen11_read_clock_frequency(uncore);
else if (GRAPHICS_VER(uncore->i915) >= 9)
return gen9_read_clock_frequency(uncore);
else if (GRAPHICS_VER(uncore->i915) >= 6)
return gen6_read_clock_frequency(uncore);
else if (GRAPHICS_VER(uncore->i915) == 5)
return gen5_read_clock_frequency(uncore);
else if (IS_G4X(uncore->i915))
return g4x_read_clock_frequency(uncore);
else if (GRAPHICS_VER(uncore->i915) == 4)
return gen4_read_clock_frequency(uncore);
else
return 0;
}
void intel_gt_init_clock_frequency(struct intel_gt *gt)
{
gt->clock_frequency = read_clock_frequency(gt->uncore);
/* Icelake appears to use another fixed frequency for CTX_TIMESTAMP */
if (GRAPHICS_VER(gt->i915) == 11)
gt->clock_period_ns = NSEC_PER_SEC / 13750000;
else if (gt->clock_frequency)
gt->clock_period_ns = intel_gt_clock_interval_to_ns(gt, 1);
GT_TRACE(gt,
"Using clock frequency: %dkHz, period: %dns, wrap: %lldms\n",
gt->clock_frequency / 1000,
gt->clock_period_ns,
div_u64(mul_u32_u32(gt->clock_period_ns, S32_MAX),
USEC_PER_SEC));
}
#if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
void intel_gt_check_clock_frequency(const struct intel_gt *gt)
{
if (gt->clock_frequency != read_clock_frequency(gt->uncore)) {
gt_err(gt, "GT clock frequency changed, was %uHz, now %uHz!\n",
gt->clock_frequency,
read_clock_frequency(gt->uncore));
}
}
#endif
static u64 div_u64_roundup(u64 nom, u32 den)
{
return div_u64(nom + den - 1, den);
}
u64 intel_gt_clock_interval_to_ns(const struct intel_gt *gt, u64 count)
{
return div_u64_roundup(count * NSEC_PER_SEC, gt->clock_frequency);
}
u64 intel_gt_pm_interval_to_ns(const struct intel_gt *gt, u64 count)
{
return intel_gt_clock_interval_to_ns(gt, 16 * count);
}
u64 intel_gt_ns_to_clock_interval(const struct intel_gt *gt, u64 ns)
{
return div_u64_roundup(gt->clock_frequency * ns, NSEC_PER_SEC);
}
u64 intel_gt_ns_to_pm_interval(const struct intel_gt *gt, u64 ns)
{
u64 val;
/*
* Make these a multiple of magic 25 to avoid SNB (eg. Dell XPS
* 8300) freezing up around GPU hangs. Looks as if even
* scheduling/timer interrupts start misbehaving if the RPS
* EI/thresholds are "bad", leading to a very sluggish or even
* frozen machine.
*/
val = div_u64_roundup(intel_gt_ns_to_clock_interval(gt, ns), 16);
if (GRAPHICS_VER(gt->i915) == 6)
val = div_u64_roundup(val, 25) * 25;
return val;
}
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