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/*
* SPDX-License-Identifier: MIT
*
* Copyright © 2019 Intel Corporation
*/
#include "i915_drv.h"
#include "intel_lrc_reg.h"
#include "intel_sseu.h"
u32 intel_sseu_make_rpcs(struct drm_i915_private *i915,
const struct intel_sseu *req_sseu)
{
const struct sseu_dev_info *sseu = &RUNTIME_INFO(i915)->sseu;
bool subslice_pg = sseu->has_subslice_pg;
struct intel_sseu ctx_sseu;
u8 slices, subslices;
u32 rpcs = 0;
/*
* No explicit RPCS request is needed to ensure full
* slice/subslice/EU enablement prior to Gen9.
*/
if (INTEL_GEN(i915) < 9)
return 0;
/*
* If i915/perf is active, we want a stable powergating configuration
* on the system.
*
* We could choose full enablement, but on ICL we know there are use
* cases which disable slices for functional, apart for performance
* reasons. So in this case we select a known stable subset.
*/
if (!i915->perf.oa.exclusive_stream) {
ctx_sseu = *req_sseu;
} else {
ctx_sseu = intel_sseu_from_device_info(sseu);
if (IS_GEN(i915, 11)) {
/*
* We only need subslice count so it doesn't matter
* which ones we select - just turn off low bits in the
* amount of half of all available subslices per slice.
*/
ctx_sseu.subslice_mask =
~(~0 << (hweight8(ctx_sseu.subslice_mask) / 2));
ctx_sseu.slice_mask = 0x1;
}
}
slices = hweight8(ctx_sseu.slice_mask);
subslices = hweight8(ctx_sseu.subslice_mask);
/*
* Since the SScount bitfield in GEN8_R_PWR_CLK_STATE is only three bits
* wide and Icelake has up to eight subslices, specfial programming is
* needed in order to correctly enable all subslices.
*
* According to documentation software must consider the configuration
* as 2x4x8 and hardware will translate this to 1x8x8.
*
* Furthemore, even though SScount is three bits, maximum documented
* value for it is four. From this some rules/restrictions follow:
*
* 1.
* If enabled subslice count is greater than four, two whole slices must
* be enabled instead.
*
* 2.
* When more than one slice is enabled, hardware ignores the subslice
* count altogether.
*
* From these restrictions it follows that it is not possible to enable
* a count of subslices between the SScount maximum of four restriction,
* and the maximum available number on a particular SKU. Either all
* subslices are enabled, or a count between one and four on the first
* slice.
*/
if (IS_GEN(i915, 11) &&
slices == 1 &&
subslices > min_t(u8, 4, hweight8(sseu->subslice_mask[0]) / 2)) {
GEM_BUG_ON(subslices & 1);
subslice_pg = false;
slices *= 2;
}
/*
* Starting in Gen9, render power gating can leave
* slice/subslice/EU in a partially enabled state. We
* must make an explicit request through RPCS for full
* enablement.
*/
if (sseu->has_slice_pg) {
u32 mask, val = slices;
if (INTEL_GEN(i915) >= 11) {
mask = GEN11_RPCS_S_CNT_MASK;
val <<= GEN11_RPCS_S_CNT_SHIFT;
} else {
mask = GEN8_RPCS_S_CNT_MASK;
val <<= GEN8_RPCS_S_CNT_SHIFT;
}
GEM_BUG_ON(val & ~mask);
val &= mask;
rpcs |= GEN8_RPCS_ENABLE | GEN8_RPCS_S_CNT_ENABLE | val;
}
if (subslice_pg) {
u32 val = subslices;
val <<= GEN8_RPCS_SS_CNT_SHIFT;
GEM_BUG_ON(val & ~GEN8_RPCS_SS_CNT_MASK);
val &= GEN8_RPCS_SS_CNT_MASK;
rpcs |= GEN8_RPCS_ENABLE | GEN8_RPCS_SS_CNT_ENABLE | val;
}
if (sseu->has_eu_pg) {
u32 val;
val = ctx_sseu.min_eus_per_subslice << GEN8_RPCS_EU_MIN_SHIFT;
GEM_BUG_ON(val & ~GEN8_RPCS_EU_MIN_MASK);
val &= GEN8_RPCS_EU_MIN_MASK;
rpcs |= val;
val = ctx_sseu.max_eus_per_subslice << GEN8_RPCS_EU_MAX_SHIFT;
GEM_BUG_ON(val & ~GEN8_RPCS_EU_MAX_MASK);
val &= GEN8_RPCS_EU_MAX_MASK;
rpcs |= val;
rpcs |= GEN8_RPCS_ENABLE;
}
return rpcs;
}
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