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path: root/drivers/gpu/drm/i915/gt/intel_sseu.c
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Diffstat (limited to 'drivers/gpu/drm/i915/gt/intel_sseu.c')
-rw-r--r--drivers/gpu/drm/i915/gt/intel_sseu.c159
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gt/intel_sseu.c b/drivers/gpu/drm/i915/gt/intel_sseu.c
new file mode 100644
index 000000000000..a0756f006f5f
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/intel_sseu.c
@@ -0,0 +1,159 @@
+/*
+ * SPDX-License-Identifier: MIT
+ *
+ * Copyright © 2019 Intel Corporation
+ */
+
+#include "i915_drv.h"
+#include "intel_lrc_reg.h"
+#include "intel_sseu.h"
+
+unsigned int
+intel_sseu_subslice_total(const struct sseu_dev_info *sseu)
+{
+ unsigned int i, total = 0;
+
+ for (i = 0; i < ARRAY_SIZE(sseu->subslice_mask); i++)
+ total += hweight8(sseu->subslice_mask[i]);
+
+ return total;
+}
+
+unsigned int
+intel_sseu_subslices_per_slice(const struct sseu_dev_info *sseu, u8 slice)
+{
+ return hweight8(sseu->subslice_mask[slice]);
+}
+
+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;
+}