--- /dev/null
+/*
+ * Copyright © 2011-2012 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ * Authors:
+ * Ben Widawsky <ben@bwidawsk.net>
+ *
+ */
+
+/*
+ * This file implements HW context support. On gen5+ a HW context consists of an
+ * opaque GPU object which is referenced at times of context saves and restores.
+ * With RC6 enabled, the context is also referenced as the GPU enters and exists
+ * from RC6 (GPU has it's own internal power context, except on gen5). Though
+ * something like a context does exist for the media ring, the code only
+ * supports contexts for the render ring.
+ *
+ * In software, there is a distinction between contexts created by the user,
+ * and the default HW context. The default HW context is used by GPU clients
+ * that do not request setup of their own hardware context. The default
+ * context's state is never restored to help prevent programming errors. This
+ * would happen if a client ran and piggy-backed off another clients GPU state.
+ * The default context only exists to give the GPU some offset to load as the
+ * current to invoke a save of the context we actually care about. In fact, the
+ * code could likely be constructed, albeit in a more complicated fashion, to
+ * never use the default context, though that limits the driver's ability to
+ * swap out, and/or destroy other contexts.
+ *
+ * All other contexts are created as a request by the GPU client. These contexts
+ * store GPU state, and thus allow GPU clients to not re-emit state (and
+ * potentially query certain state) at any time. The kernel driver makes
+ * certain that the appropriate commands are inserted.
+ *
+ * The context life cycle is semi-complicated in that context BOs may live
+ * longer than the context itself because of the way the hardware, and object
+ * tracking works. Below is a very crude representation of the state machine
+ * describing the context life.
+ * refcount pincount active
+ * S0: initial state 0 0 0
+ * S1: context created 1 0 0
+ * S2: context is currently running 2 1 X
+ * S3: GPU referenced, but not current 2 0 1
+ * S4: context is current, but destroyed 1 1 0
+ * S5: like S3, but destroyed 1 0 1
+ *
+ * The most common (but not all) transitions:
+ * S0->S1: client creates a context
+ * S1->S2: client submits execbuf with context
+ * S2->S3: other clients submits execbuf with context
+ * S3->S1: context object was retired
+ * S3->S2: clients submits another execbuf
+ * S2->S4: context destroy called with current context
+ * S3->S5->S0: destroy path
+ * S4->S5->S0: destroy path on current context
+ *
+ * There are two confusing terms used above:
+ * The "current context" means the context which is currently running on the
+ * GPU. The GPU has loaded its state already and has stored away the gtt
+ * offset of the BO. The GPU is not actively referencing the data at this
+ * offset, but it will on the next context switch. The only way to avoid this
+ * is to do a GPU reset.
+ *
+ * An "active context' is one which was previously the "current context" and is
+ * on the active list waiting for the next context switch to occur. Until this
+ * happens, the object must remain at the same gtt offset. It is therefore
+ * possible to destroy a context, but it is still active.
+ *
+ */
+
+#include <drm/drmP.h>
+#include <drm/i915_drm.h>
+#include "i915_drv.h"
+#include "i915_trace.h"
+
+/* This is a HW constraint. The value below is the largest known requirement
+ * I've seen in a spec to date, and that was a workaround for a non-shipping
+ * part. It should be safe to decrease this, but it's more future proof as is.
+ */
+#define GEN6_CONTEXT_ALIGN (64<<10)
+#define GEN7_CONTEXT_ALIGN 4096
+
+static size_t get_context_alignment(struct drm_device *dev)
+{
+ if (IS_GEN6(dev))
+ return GEN6_CONTEXT_ALIGN;
+
+ return GEN7_CONTEXT_ALIGN;
+}
+
+static int get_context_size(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ int ret;
+ u32 reg;
+
+ switch (INTEL_INFO(dev)->gen) {
+ case 6:
+ reg = I915_READ(CXT_SIZE);
+ ret = GEN6_CXT_TOTAL_SIZE(reg) * 64;
+ break;
+ case 7:
+ reg = I915_READ(GEN7_CXT_SIZE);
+ if (IS_HASWELL(dev))
+ ret = HSW_CXT_TOTAL_SIZE;
+ else
+ ret = GEN7_CXT_TOTAL_SIZE(reg) * 64;
+ break;
+ case 8:
+ ret = GEN8_CXT_TOTAL_SIZE;
+ break;
+ default:
+ BUG();
+ }
+
+ return ret;
+}
+
+void i915_gem_context_free(struct kref *ctx_ref)
+{
+ struct intel_context *ctx = container_of(ctx_ref,
+ typeof(*ctx), ref);
+
+ trace_i915_context_free(ctx);
+
+ if (i915.enable_execlists)
+ intel_lr_context_free(ctx);
+
+ i915_ppgtt_put(ctx->ppgtt);
+
+ if (ctx->legacy_hw_ctx.rcs_state)
+ drm_gem_object_unreference(&ctx->legacy_hw_ctx.rcs_state->base);
+ list_del(&ctx->link);
+ kfree(ctx);
+}
+
+struct drm_i915_gem_object *
+i915_gem_alloc_context_obj(struct drm_device *dev, size_t size)
+{
+ struct drm_i915_gem_object *obj;
+ int ret;
+
+ obj = i915_gem_alloc_object(dev, size);
+ if (obj == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * Try to make the context utilize L3 as well as LLC.
+ *
+ * On VLV we don't have L3 controls in the PTEs so we
+ * shouldn't touch the cache level, especially as that
+ * would make the object snooped which might have a
+ * negative performance impact.
+ */
+ if (INTEL_INFO(dev)->gen >= 7 && !IS_VALLEYVIEW(dev)) {
+ ret = i915_gem_object_set_cache_level(obj, I915_CACHE_L3_LLC);
+ /* Failure shouldn't ever happen this early */
+ if (WARN_ON(ret)) {
+ drm_gem_object_unreference(&obj->base);
+ return ERR_PTR(ret);
+ }
+ }
+
+ return obj;
+}
+
+static struct intel_context *
+__create_hw_context(struct drm_device *dev,
+ struct drm_i915_file_private *file_priv)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct intel_context *ctx;
+ int ret;
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (ctx == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ kref_init(&ctx->ref);
+ list_add_tail(&ctx->link, &dev_priv->context_list);
+
+ if (dev_priv->hw_context_size) {
+ struct drm_i915_gem_object *obj =
+ i915_gem_alloc_context_obj(dev, dev_priv->hw_context_size);
+ if (IS_ERR(obj)) {
+ ret = PTR_ERR(obj);
+ goto err_out;
+ }
+ ctx->legacy_hw_ctx.rcs_state = obj;
+ }
+
+ /* Default context will never have a file_priv */
+ if (file_priv != NULL) {
+ ret = idr_alloc(&file_priv->context_idr, ctx,
+ DEFAULT_CONTEXT_HANDLE, 0, GFP_KERNEL);
+ if (ret < 0)
+ goto err_out;
+ } else
+ ret = DEFAULT_CONTEXT_HANDLE;
+
+ ctx->file_priv = file_priv;
+ ctx->user_handle = ret;
+ /* NB: Mark all slices as needing a remap so that when the context first
+ * loads it will restore whatever remap state already exists. If there
+ * is no remap info, it will be a NOP. */
+ ctx->remap_slice = (1 << NUM_L3_SLICES(dev)) - 1;
+
+ ctx->hang_stats.ban_period_seconds = DRM_I915_CTX_BAN_PERIOD;
+
+ return ctx;
+
+err_out:
+ i915_gem_context_unreference(ctx);
+ return ERR_PTR(ret);
+}
+
+/**
+ * The default context needs to exist per ring that uses contexts. It stores the
+ * context state of the GPU for applications that don't utilize HW contexts, as
+ * well as an idle case.
+ */
+static struct intel_context *
+i915_gem_create_context(struct drm_device *dev,
+ struct drm_i915_file_private *file_priv)
+{
+ const bool is_global_default_ctx = file_priv == NULL;
+ struct intel_context *ctx;
+ int ret = 0;
+
+ BUG_ON(!mutex_is_locked(&dev->struct_mutex));
+
+ ctx = __create_hw_context(dev, file_priv);
+ if (IS_ERR(ctx))
+ return ctx;
+
+ if (is_global_default_ctx && ctx->legacy_hw_ctx.rcs_state) {
+ /* We may need to do things with the shrinker which
+ * require us to immediately switch back to the default
+ * context. This can cause a problem as pinning the
+ * default context also requires GTT space which may not
+ * be available. To avoid this we always pin the default
+ * context.
+ */
+ ret = i915_gem_obj_ggtt_pin(ctx->legacy_hw_ctx.rcs_state,
+ get_context_alignment(dev), 0);
+ if (ret) {
+ DRM_DEBUG_DRIVER("Couldn't pin %d\n", ret);
+ goto err_destroy;
+ }
+ }
+
+ if (USES_FULL_PPGTT(dev)) {
+ struct i915_hw_ppgtt *ppgtt = i915_ppgtt_create(dev, file_priv);
+
+ if (IS_ERR_OR_NULL(ppgtt)) {
+ DRM_DEBUG_DRIVER("PPGTT setup failed (%ld)\n",
+ PTR_ERR(ppgtt));
+ ret = PTR_ERR(ppgtt);
+ goto err_unpin;
+ }
+
+ ctx->ppgtt = ppgtt;
+ }
+
+ trace_i915_context_create(ctx);
+
+ return ctx;
+
+err_unpin:
+ if (is_global_default_ctx && ctx->legacy_hw_ctx.rcs_state)
+ i915_gem_object_ggtt_unpin(ctx->legacy_hw_ctx.rcs_state);
+err_destroy:
+ i915_gem_context_unreference(ctx);
+ return ERR_PTR(ret);
+}
+
+void i915_gem_context_reset(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ int i;
+
+ if (i915.enable_execlists) {
+ struct intel_context *ctx;
+
+ list_for_each_entry(ctx, &dev_priv->context_list, link) {
+ intel_lr_context_reset(dev, ctx);
+ }
+
+ return;
+ }
+
+ for (i = 0; i < I915_NUM_RINGS; i++) {
+ struct intel_engine_cs *ring = &dev_priv->ring[i];
+ struct intel_context *lctx = ring->last_context;
+
+ if (lctx) {
+ if (lctx->legacy_hw_ctx.rcs_state && i == RCS)
+ i915_gem_object_ggtt_unpin(lctx->legacy_hw_ctx.rcs_state);
+
+ i915_gem_context_unreference(lctx);
+ ring->last_context = NULL;
+ }
+ }
+}
+
+int i915_gem_context_init(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct intel_context *ctx;
+ int i;
+
+ /* Init should only be called once per module load. Eventually the
+ * restriction on the context_disabled check can be loosened. */
+ if (WARN_ON(dev_priv->ring[RCS].default_context))
+ return 0;
+
+ if (i915.enable_execlists) {
+ /* NB: intentionally left blank. We will allocate our own
+ * backing objects as we need them, thank you very much */
+ dev_priv->hw_context_size = 0;
+ } else if (HAS_HW_CONTEXTS(dev)) {
+ dev_priv->hw_context_size = round_up(get_context_size(dev), 4096);
+ if (dev_priv->hw_context_size > (1<<20)) {
+ DRM_DEBUG_DRIVER("Disabling HW Contexts; invalid size %d\n",
+ dev_priv->hw_context_size);
+ dev_priv->hw_context_size = 0;
+ }
+ }
+
+ ctx = i915_gem_create_context(dev, NULL);
+ if (IS_ERR(ctx)) {
+ DRM_ERROR("Failed to create default global context (error %ld)\n",
+ PTR_ERR(ctx));
+ return PTR_ERR(ctx);
+ }
+
+ for (i = 0; i < I915_NUM_RINGS; i++) {
+ struct intel_engine_cs *ring = &dev_priv->ring[i];
+
+ /* NB: RCS will hold a ref for all rings */
+ ring->default_context = ctx;
+ }
+
+ DRM_DEBUG_DRIVER("%s context support initialized\n",
+ i915.enable_execlists ? "LR" :
+ dev_priv->hw_context_size ? "HW" : "fake");
+ return 0;
+}
+
+void i915_gem_context_fini(struct drm_device *dev)
+{
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct intel_context *dctx = dev_priv->ring[RCS].default_context;
+ int i;
+
+ if (dctx->legacy_hw_ctx.rcs_state) {
+ /* The only known way to stop the gpu from accessing the hw context is
+ * to reset it. Do this as the very last operation to avoid confusing
+ * other code, leading to spurious errors. */
+ intel_gpu_reset(dev);
+
+ /* When default context is created and switched to, base object refcount
+ * will be 2 (+1 from object creation and +1 from do_switch()).
+ * i915_gem_context_fini() will be called after gpu_idle() has switched
+ * to default context. So we need to unreference the base object once
+ * to offset the do_switch part, so that i915_gem_context_unreference()
+ * can then free the base object correctly. */
+ WARN_ON(!dev_priv->ring[RCS].last_context);
+ if (dev_priv->ring[RCS].last_context == dctx) {
+ /* Fake switch to NULL context */
+ WARN_ON(dctx->legacy_hw_ctx.rcs_state->active);
+ i915_gem_object_ggtt_unpin(dctx->legacy_hw_ctx.rcs_state);
+ i915_gem_context_unreference(dctx);
+ dev_priv->ring[RCS].last_context = NULL;
+ }
+
+ i915_gem_object_ggtt_unpin(dctx->legacy_hw_ctx.rcs_state);
+ }
+
+ for (i = 0; i < I915_NUM_RINGS; i++) {
+ struct intel_engine_cs *ring = &dev_priv->ring[i];
+
+ if (ring->last_context)
+ i915_gem_context_unreference(ring->last_context);
+
+ ring->default_context = NULL;
+ ring->last_context = NULL;
+ }
+
+ i915_gem_context_unreference(dctx);
+}
+
+int i915_gem_context_enable(struct drm_i915_private *dev_priv)
+{
+ struct intel_engine_cs *ring;
+ int ret, i;
+
+ BUG_ON(!dev_priv->ring[RCS].default_context);
+
+ if (i915.enable_execlists) {
+ for_each_ring(ring, dev_priv, i) {
+ if (ring->init_context) {
+ ret = ring->init_context(ring,
+ ring->default_context);
+ if (ret) {
+ DRM_ERROR("ring init context: %d\n",
+ ret);
+ return ret;
+ }
+ }
+ }
+
+ } else
+ for_each_ring(ring, dev_priv, i) {
+ ret = i915_switch_context(ring, ring->default_context);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int context_idr_cleanup(int id, void *p, void *data)
+{
+ struct intel_context *ctx = p;
+
+ i915_gem_context_unreference(ctx);
+ return 0;
+}
+
+int i915_gem_context_open(struct drm_device *dev, struct drm_file *file)
+{
+ struct drm_i915_file_private *file_priv = file->driver_priv;
+ struct intel_context *ctx;
+
+ idr_init(&file_priv->context_idr);
+
+ mutex_lock(&dev->struct_mutex);
+ ctx = i915_gem_create_context(dev, file_priv);
+ mutex_unlock(&dev->struct_mutex);
+
+ if (IS_ERR(ctx)) {
+ idr_destroy(&file_priv->context_idr);
+ return PTR_ERR(ctx);
+ }
+
+ return 0;
+}
+
+void i915_gem_context_close(struct drm_device *dev, struct drm_file *file)
+{
+ struct drm_i915_file_private *file_priv = file->driver_priv;
+
+ idr_for_each(&file_priv->context_idr, context_idr_cleanup, NULL);
+ idr_destroy(&file_priv->context_idr);
+}
+
+struct intel_context *
+i915_gem_context_get(struct drm_i915_file_private *file_priv, u32 id)
+{
+ struct intel_context *ctx;
+
+ ctx = (struct intel_context *)idr_find(&file_priv->context_idr, id);
+ if (!ctx)
+ return ERR_PTR(-ENOENT);
+
+ return ctx;
+}
+
+static inline int
+mi_set_context(struct intel_engine_cs *ring,
+ struct intel_context *new_context,
+ u32 hw_flags)
+{
+ u32 flags = hw_flags | MI_MM_SPACE_GTT;
+ const int num_rings =
+ /* Use an extended w/a on ivb+ if signalling from other rings */
+ i915_semaphore_is_enabled(ring->dev) ?
+ hweight32(INTEL_INFO(ring->dev)->ring_mask) - 1 :
+ 0;
+ int len, i, ret;
+
+ /* w/a: If Flush TLB Invalidation Mode is enabled, driver must do a TLB
+ * invalidation prior to MI_SET_CONTEXT. On GEN6 we don't set the value
+ * explicitly, so we rely on the value at ring init, stored in
+ * itlb_before_ctx_switch.
+ */
+ if (IS_GEN6(ring->dev)) {
+ ret = ring->flush(ring, I915_GEM_GPU_DOMAINS, 0);
+ if (ret)
+ return ret;
+ }
+
+ /* These flags are for resource streamer on HSW+ */
+ if (!IS_HASWELL(ring->dev) && INTEL_INFO(ring->dev)->gen < 8)
+ flags |= (MI_SAVE_EXT_STATE_EN | MI_RESTORE_EXT_STATE_EN);
+
+
+ len = 4;
+ if (INTEL_INFO(ring->dev)->gen >= 7)
+ len += 2 + (num_rings ? 4*num_rings + 2 : 0);
+
+ ret = intel_ring_begin(ring, len);
+ if (ret)
+ return ret;
+
+ /* WaProgramMiArbOnOffAroundMiSetContext:ivb,vlv,hsw,bdw,chv */
+ if (INTEL_INFO(ring->dev)->gen >= 7) {
+ intel_ring_emit(ring, MI_ARB_ON_OFF | MI_ARB_DISABLE);
+ if (num_rings) {
+ struct intel_engine_cs *signaller;
+
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(num_rings));
+ for_each_ring(signaller, to_i915(ring->dev), i) {
+ if (signaller == ring)
+ continue;
+
+ intel_ring_emit(ring, RING_PSMI_CTL(signaller->mmio_base));
+ intel_ring_emit(ring, _MASKED_BIT_ENABLE(GEN6_PSMI_SLEEP_MSG_DISABLE));
+ }
+ }
+ }
+
+ intel_ring_emit(ring, MI_NOOP);
+ intel_ring_emit(ring, MI_SET_CONTEXT);
+ intel_ring_emit(ring, i915_gem_obj_ggtt_offset(new_context->legacy_hw_ctx.rcs_state) |
+ flags);
+ /*
+ * w/a: MI_SET_CONTEXT must always be followed by MI_NOOP
+ * WaMiSetContext_Hang:snb,ivb,vlv
+ */
+ intel_ring_emit(ring, MI_NOOP);
+
+ if (INTEL_INFO(ring->dev)->gen >= 7) {
+ if (num_rings) {
+ struct intel_engine_cs *signaller;
+
+ intel_ring_emit(ring, MI_LOAD_REGISTER_IMM(num_rings));
+ for_each_ring(signaller, to_i915(ring->dev), i) {
+ if (signaller == ring)
+ continue;
+
+ intel_ring_emit(ring, RING_PSMI_CTL(signaller->mmio_base));
+ intel_ring_emit(ring, _MASKED_BIT_DISABLE(GEN6_PSMI_SLEEP_MSG_DISABLE));
+ }
+ }
+ intel_ring_emit(ring, MI_ARB_ON_OFF | MI_ARB_ENABLE);
+ }
+
+ intel_ring_advance(ring);
+
+ return ret;
+}
+
+static inline bool should_skip_switch(struct intel_engine_cs *ring,
+ struct intel_context *from,
+ struct intel_context *to)
+{
+ struct drm_i915_private *dev_priv = ring->dev->dev_private;
+
+ if (to->remap_slice)
+ return false;
+
+ if (to->ppgtt) {
+ if (from == to && !test_bit(ring->id,
+ &to->ppgtt->pd_dirty_rings))
+ return true;
+ } else if (dev_priv->mm.aliasing_ppgtt) {
+ if (from == to && !test_bit(ring->id,
+ &dev_priv->mm.aliasing_ppgtt->pd_dirty_rings))
+ return true;
+ }
+
+ return false;
+}
+
+static bool
+needs_pd_load_pre(struct intel_engine_cs *ring, struct intel_context *to)
+{
+ struct drm_i915_private *dev_priv = ring->dev->dev_private;
+
+ if (!to->ppgtt)
+ return false;
+
+ if (INTEL_INFO(ring->dev)->gen < 8)
+ return true;
+
+ if (ring != &dev_priv->ring[RCS])
+ return true;
+
+ return false;
+}
+
+static bool
+needs_pd_load_post(struct intel_engine_cs *ring, struct intel_context *to,
+ u32 hw_flags)
+{
+ struct drm_i915_private *dev_priv = ring->dev->dev_private;
+
+ if (!to->ppgtt)
+ return false;
+
+ if (!IS_GEN8(ring->dev))
+ return false;
+
+ if (ring != &dev_priv->ring[RCS])
+ return false;
+
+ if (hw_flags & MI_RESTORE_INHIBIT)
+ return true;
+
+ return false;
+}
+
+static int do_switch(struct intel_engine_cs *ring,
+ struct intel_context *to)
+{
+ struct drm_i915_private *dev_priv = ring->dev->dev_private;
+ struct intel_context *from = ring->last_context;
+ u32 hw_flags = 0;
+ bool uninitialized = false;
+ struct i915_vma *vma;
+ int ret, i;
+
+ if (from != NULL && ring == &dev_priv->ring[RCS]) {
+ BUG_ON(from->legacy_hw_ctx.rcs_state == NULL);
+ BUG_ON(!i915_gem_obj_is_pinned(from->legacy_hw_ctx.rcs_state));
+ }
+
+ if (should_skip_switch(ring, from, to))
+ return 0;
+
+ /* Trying to pin first makes error handling easier. */
+ if (ring == &dev_priv->ring[RCS]) {
+ ret = i915_gem_obj_ggtt_pin(to->legacy_hw_ctx.rcs_state,
+ get_context_alignment(ring->dev), 0);
+ if (ret)
+ return ret;
+ }
+
+ /*
+ * Pin can switch back to the default context if we end up calling into
+ * evict_everything - as a last ditch gtt defrag effort that also
+ * switches to the default context. Hence we need to reload from here.
+ */
+ from = ring->last_context;
+
+ if (needs_pd_load_pre(ring, to)) {
+ /* Older GENs and non render rings still want the load first,
+ * "PP_DCLV followed by PP_DIR_BASE register through Load
+ * Register Immediate commands in Ring Buffer before submitting
+ * a context."*/
+ trace_switch_mm(ring, to);
+ ret = to->ppgtt->switch_mm(to->ppgtt, ring);
+ if (ret)
+ goto unpin_out;
+
+ /* Doing a PD load always reloads the page dirs */
+ clear_bit(ring->id, &to->ppgtt->pd_dirty_rings);
+ }
+
+ if (ring != &dev_priv->ring[RCS]) {
+ if (from)
+ i915_gem_context_unreference(from);
+ goto done;
+ }
+
+ /*
+ * Clear this page out of any CPU caches for coherent swap-in/out. Note
+ * that thanks to write = false in this call and us not setting any gpu
+ * write domains when putting a context object onto the active list
+ * (when switching away from it), this won't block.
+ *
+ * XXX: We need a real interface to do this instead of trickery.
+ */
+ ret = i915_gem_object_set_to_gtt_domain(to->legacy_hw_ctx.rcs_state, false);
+ if (ret)
+ goto unpin_out;
+
+ vma = i915_gem_obj_to_ggtt(to->legacy_hw_ctx.rcs_state);
+ if (!(vma->bound & GLOBAL_BIND)) {
+ ret = i915_vma_bind(vma,
+ to->legacy_hw_ctx.rcs_state->cache_level,
+ GLOBAL_BIND);
+ /* This shouldn't ever fail. */
+ if (WARN_ONCE(ret, "GGTT context bind failed!"))
+ goto unpin_out;
+ }
+
+ if (!to->legacy_hw_ctx.initialized) {
+ hw_flags |= MI_RESTORE_INHIBIT;
+ /* NB: If we inhibit the restore, the context is not allowed to
+ * die because future work may end up depending on valid address
+ * space. This means we must enforce that a page table load
+ * occur when this occurs. */
+ } else if (to->ppgtt &&
+ test_and_clear_bit(ring->id, &to->ppgtt->pd_dirty_rings))
+ hw_flags |= MI_FORCE_RESTORE;
+
+ /* We should never emit switch_mm more than once */
+ WARN_ON(needs_pd_load_pre(ring, to) &&
+ needs_pd_load_post(ring, to, hw_flags));
+
+ ret = mi_set_context(ring, to, hw_flags);
+ if (ret)
+ goto unpin_out;
+
+ /* GEN8 does *not* require an explicit reload if the PDPs have been
+ * setup, and we do not wish to move them.
+ */
+ if (needs_pd_load_post(ring, to, hw_flags)) {
+ trace_switch_mm(ring, to);
+ ret = to->ppgtt->switch_mm(to->ppgtt, ring);
+ /* The hardware context switch is emitted, but we haven't
+ * actually changed the state - so it's probably safe to bail
+ * here. Still, let the user know something dangerous has
+ * happened.
+ */
+ if (ret) {
+ DRM_ERROR("Failed to change address space on context switch\n");
+ goto unpin_out;
+ }
+ }
+
+ for (i = 0; i < MAX_L3_SLICES; i++) {
+ if (!(to->remap_slice & (1<<i)))
+ continue;
+
+ ret = i915_gem_l3_remap(ring, i);
+ /* If it failed, try again next round */
+ if (ret)
+ DRM_DEBUG_DRIVER("L3 remapping failed\n");
+ else
+ to->remap_slice &= ~(1<<i);
+ }
+
+ /* The backing object for the context is done after switching to the
+ * *next* context. Therefore we cannot retire the previous context until
+ * the next context has already started running. In fact, the below code
+ * is a bit suboptimal because the retiring can occur simply after the
+ * MI_SET_CONTEXT instead of when the next seqno has completed.
+ */
+ if (from != NULL) {
+ from->legacy_hw_ctx.rcs_state->base.read_domains = I915_GEM_DOMAIN_INSTRUCTION;
+ i915_vma_move_to_active(i915_gem_obj_to_ggtt(from->legacy_hw_ctx.rcs_state), ring);
+ /* As long as MI_SET_CONTEXT is serializing, ie. it flushes the
+ * whole damn pipeline, we don't need to explicitly mark the
+ * object dirty. The only exception is that the context must be
+ * correct in case the object gets swapped out. Ideally we'd be
+ * able to defer doing this until we know the object would be
+ * swapped, but there is no way to do that yet.
+ */
+ from->legacy_hw_ctx.rcs_state->dirty = 1;
+ BUG_ON(i915_gem_request_get_ring(
+ from->legacy_hw_ctx.rcs_state->last_read_req) != ring);
+
+ /* obj is kept alive until the next request by its active ref */
+ i915_gem_object_ggtt_unpin(from->legacy_hw_ctx.rcs_state);
+ i915_gem_context_unreference(from);
+ }
+
+ uninitialized = !to->legacy_hw_ctx.initialized;
+ to->legacy_hw_ctx.initialized = true;
+
+done:
+ i915_gem_context_reference(to);
+ ring->last_context = to;
+
+ if (uninitialized) {
+ if (ring->init_context) {
+ ret = ring->init_context(ring, to);
+ if (ret)
+ DRM_ERROR("ring init context: %d\n", ret);
+ }
+ }
+
+ return 0;
+
+unpin_out:
+ if (ring->id == RCS)
+ i915_gem_object_ggtt_unpin(to->legacy_hw_ctx.rcs_state);
+ return ret;
+}
+
+/**
+ * i915_switch_context() - perform a GPU context switch.
+ * @ring: ring for which we'll execute the context switch
+ * @to: the context to switch to
+ *
+ * The context life cycle is simple. The context refcount is incremented and
+ * decremented by 1 and create and destroy. If the context is in use by the GPU,
+ * it will have a refcount > 1. This allows us to destroy the context abstract
+ * object while letting the normal object tracking destroy the backing BO.
+ *
+ * This function should not be used in execlists mode. Instead the context is
+ * switched by writing to the ELSP and requests keep a reference to their
+ * context.
+ */
+int i915_switch_context(struct intel_engine_cs *ring,
+ struct intel_context *to)
+{
+ struct drm_i915_private *dev_priv = ring->dev->dev_private;
+
+ WARN_ON(i915.enable_execlists);
+ WARN_ON(!mutex_is_locked(&dev_priv->dev->struct_mutex));
+
+ if (to->legacy_hw_ctx.rcs_state == NULL) { /* We have the fake context */
+ if (to != ring->last_context) {
+ i915_gem_context_reference(to);
+ if (ring->last_context)
+ i915_gem_context_unreference(ring->last_context);
+ ring->last_context = to;
+ }
+ return 0;
+ }
+
+ return do_switch(ring, to);
+}
+
+static bool contexts_enabled(struct drm_device *dev)
+{
+ return i915.enable_execlists || to_i915(dev)->hw_context_size;
+}
+
+int i915_gem_context_create_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file)
+{
+ struct drm_i915_gem_context_create *args = data;
+ struct drm_i915_file_private *file_priv = file->driver_priv;
+ struct intel_context *ctx;
+ int ret;
+
+ if (!contexts_enabled(dev))
+ return -ENODEV;
+
+ ret = i915_mutex_lock_interruptible(dev);
+ if (ret)
+ return ret;
+
+ ctx = i915_gem_create_context(dev, file_priv);
+ mutex_unlock(&dev->struct_mutex);
+ if (IS_ERR(ctx))
+ return PTR_ERR(ctx);
+
+ args->ctx_id = ctx->user_handle;
+ DRM_DEBUG_DRIVER("HW context %d created\n", args->ctx_id);
+
+ return 0;
+}
+
+int i915_gem_context_destroy_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file)
+{
+ struct drm_i915_gem_context_destroy *args = data;
+ struct drm_i915_file_private *file_priv = file->driver_priv;
+ struct intel_context *ctx;
+ int ret;
+
+ if (args->ctx_id == DEFAULT_CONTEXT_HANDLE)
+ return -ENOENT;
+
+ ret = i915_mutex_lock_interruptible(dev);
+ if (ret)
+ return ret;
+
+ ctx = i915_gem_context_get(file_priv, args->ctx_id);
+ if (IS_ERR(ctx)) {
+ mutex_unlock(&dev->struct_mutex);
+ return PTR_ERR(ctx);
+ }
+
+ idr_remove(&ctx->file_priv->context_idr, ctx->user_handle);
+ i915_gem_context_unreference(ctx);
+ mutex_unlock(&dev->struct_mutex);
+
+ DRM_DEBUG_DRIVER("HW context %d destroyed\n", args->ctx_id);
+ return 0;
+}
+
+int i915_gem_context_getparam_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file)
+{
+ struct drm_i915_file_private *file_priv = file->driver_priv;
+ struct drm_i915_gem_context_param *args = data;
+ struct intel_context *ctx;
+ int ret;
+
+ ret = i915_mutex_lock_interruptible(dev);
+ if (ret)
+ return ret;
+
+ ctx = i915_gem_context_get(file_priv, args->ctx_id);
+ if (IS_ERR(ctx)) {
+ mutex_unlock(&dev->struct_mutex);
+ return PTR_ERR(ctx);
+ }
+
+ args->size = 0;
+ switch (args->param) {
+ case I915_CONTEXT_PARAM_BAN_PERIOD:
+ args->value = ctx->hang_stats.ban_period_seconds;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ mutex_unlock(&dev->struct_mutex);
+
+ return ret;
+}
+
+int i915_gem_context_setparam_ioctl(struct drm_device *dev, void *data,
+ struct drm_file *file)
+{
+ struct drm_i915_file_private *file_priv = file->driver_priv;
+ struct drm_i915_gem_context_param *args = data;
+ struct intel_context *ctx;
+ int ret;
+
+ ret = i915_mutex_lock_interruptible(dev);
+ if (ret)
+ return ret;
+
+ ctx = i915_gem_context_get(file_priv, args->ctx_id);
+ if (IS_ERR(ctx)) {
+ mutex_unlock(&dev->struct_mutex);
+ return PTR_ERR(ctx);
+ }
+
+ switch (args->param) {
+ case I915_CONTEXT_PARAM_BAN_PERIOD:
+ if (args->size)
+ ret = -EINVAL;
+ else if (args->value < ctx->hang_stats.ban_period_seconds &&
+ !capable(CAP_SYS_ADMIN))
+ ret = -EPERM;
+ else
+ ctx->hang_stats.ban_period_seconds = args->value;
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+ mutex_unlock(&dev->struct_mutex);
+
+ return ret;
+}
Code Review / kvmfornfv.git / blobdiff