drm/i915/gt: Split low level gen2-7 CS emitters

Pull the routines for writing CS packets out of intel_ring_submission
into their own files. These are low level operations for building CS
instructions, rather than the logic for filling the global ring buffer
with requests, and we will want to reuse them outside of this context.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200601072446.19548-2-chris@chris-wilson.co.uk

1 files changed, 455 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/gt/gen6_engine_cs.c b/drivers/gpu/drm/i915/gt/gen6_engine_cs.c
new file mode 100644
index 000000000000..ce38d1bcaba3
--- /dev/null
+++ b/drivers/gpu/drm/i915/gt/gen6_engine_cs.c
@@ -0,0 +1,455 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2020 Intel Corporation
+ */
+
+#include "gen6_engine_cs.h"
+#include "intel_engine.h"
+#include "intel_gpu_commands.h"
+#include "intel_gt.h"
+#include "intel_gt_irq.h"
+#include "intel_gt_pm_irq.h"
+#include "intel_ring.h"
+
+#define HWS_SCRATCH_ADDR	(I915_GEM_HWS_SCRATCH * sizeof(u32))
+
+/*
+ * Emits a PIPE_CONTROL with a non-zero post-sync operation, for
+ * implementing two workarounds on gen6.  From section 1.4.7.1
+ * "PIPE_CONTROL" of the Sandy Bridge PRM volume 2 part 1:
+ *
+ * [DevSNB-C+{W/A}] Before any depth stall flush (including those
+ * produced by non-pipelined state commands), software needs to first
+ * send a PIPE_CONTROL with no bits set except Post-Sync Operation !=
+ * 0.
+ *
+ * [Dev-SNB{W/A}]: Before a PIPE_CONTROL with Write Cache Flush Enable
+ * =1, a PIPE_CONTROL with any non-zero post-sync-op is required.
+ *
+ * And the workaround for these two requires this workaround first:
+ *
+ * [Dev-SNB{W/A}]: Pipe-control with CS-stall bit set must be sent
+ * BEFORE the pipe-control with a post-sync op and no write-cache
+ * flushes.
+ *
+ * And this last workaround is tricky because of the requirements on
+ * that bit.  From section 1.4.7.2.3 "Stall" of the Sandy Bridge PRM
+ * volume 2 part 1:
+ *
+ *     "1 of the following must also be set:
+ *      - Render Target Cache Flush Enable ([12] of DW1)
+ *      - Depth Cache Flush Enable ([0] of DW1)
+ *      - Stall at Pixel Scoreboard ([1] of DW1)
+ *      - Depth Stall ([13] of DW1)
+ *      - Post-Sync Operation ([13] of DW1)
+ *      - Notify Enable ([8] of DW1)"
+ *
+ * The cache flushes require the workaround flush that triggered this
+ * one, so we can't use it.  Depth stall would trigger the same.
+ * Post-sync nonzero is what triggered this second workaround, so we
+ * can't use that one either.  Notify enable is IRQs, which aren't
+ * really our business.  That leaves only stall at scoreboard.
+ */
+static int
+gen6_emit_post_sync_nonzero_flush(struct i915_request *rq)
+{
+	u32 scratch_addr =
+		intel_gt_scratch_offset(rq->engine->gt,
+					INTEL_GT_SCRATCH_FIELD_RENDER_FLUSH);
+	u32 *cs;
+
+	cs = intel_ring_begin(rq, 6);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	*cs++ = GFX_OP_PIPE_CONTROL(5);
+	*cs++ = PIPE_CONTROL_CS_STALL | PIPE_CONTROL_STALL_AT_SCOREBOARD;
+	*cs++ = scratch_addr | PIPE_CONTROL_GLOBAL_GTT;
+	*cs++ = 0; /* low dword */
+	*cs++ = 0; /* high dword */
+	*cs++ = MI_NOOP;
+	intel_ring_advance(rq, cs);
+
+	cs = intel_ring_begin(rq, 6);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	*cs++ = GFX_OP_PIPE_CONTROL(5);
+	*cs++ = PIPE_CONTROL_QW_WRITE;
+	*cs++ = scratch_addr | PIPE_CONTROL_GLOBAL_GTT;
+	*cs++ = 0;
+	*cs++ = 0;
+	*cs++ = MI_NOOP;
+	intel_ring_advance(rq, cs);
+
+	return 0;
+}
+
+int gen6_emit_flush_rcs(struct i915_request *rq, u32 mode)
+{
+	u32 scratch_addr =
+		intel_gt_scratch_offset(rq->engine->gt,
+					INTEL_GT_SCRATCH_FIELD_RENDER_FLUSH);
+	u32 *cs, flags = 0;
+	int ret;
+
+	/* Force SNB workarounds for PIPE_CONTROL flushes */
+	ret = gen6_emit_post_sync_nonzero_flush(rq);
+	if (ret)
+		return ret;
+
+	/*
+	 * Just flush everything.  Experiments have shown that reducing the
+	 * number of bits based on the write domains has little performance
+	 * impact. And when rearranging requests, the order of flushes is
+	 * unknown.
+	 */
+	if (mode & EMIT_FLUSH) {
+		flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
+		flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
+		/*
+		 * Ensure that any following seqno writes only happen
+		 * when the render cache is indeed flushed.
+		 */
+		flags |= PIPE_CONTROL_CS_STALL;
+	}
+	if (mode & EMIT_INVALIDATE) {
+		flags |= PIPE_CONTROL_TLB_INVALIDATE;
+		flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
+		flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
+		flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
+		flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
+		flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
+		/*
+		 * TLB invalidate requires a post-sync write.
+		 */
+		flags |= PIPE_CONTROL_QW_WRITE | PIPE_CONTROL_CS_STALL;
+	}
+
+	cs = intel_ring_begin(rq, 4);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = flags;
+	*cs++ = scratch_addr | PIPE_CONTROL_GLOBAL_GTT;
+	*cs++ = 0;
+	intel_ring_advance(rq, cs);
+
+	return 0;
+}
+
+u32 *gen6_emit_breadcrumb_rcs(struct i915_request *rq, u32 *cs)
+{
+	/* First we do the gen6_emit_post_sync_nonzero_flush w/a */
+	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = PIPE_CONTROL_CS_STALL | PIPE_CONTROL_STALL_AT_SCOREBOARD;
+	*cs++ = 0;
+	*cs++ = 0;
+
+	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = PIPE_CONTROL_QW_WRITE;
+	*cs++ = intel_gt_scratch_offset(rq->engine->gt,
+					INTEL_GT_SCRATCH_FIELD_DEFAULT) |
+		PIPE_CONTROL_GLOBAL_GTT;
+	*cs++ = 0;
+
+	/* Finally we can flush and with it emit the breadcrumb */
+	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = (PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
+		 PIPE_CONTROL_DEPTH_CACHE_FLUSH |
+		 PIPE_CONTROL_DC_FLUSH_ENABLE |
+		 PIPE_CONTROL_QW_WRITE |
+		 PIPE_CONTROL_CS_STALL);
+	*cs++ = i915_request_active_timeline(rq)->hwsp_offset |
+		PIPE_CONTROL_GLOBAL_GTT;
+	*cs++ = rq->fence.seqno;
+
+	*cs++ = MI_USER_INTERRUPT;
+	*cs++ = MI_NOOP;
+
+	rq->tail = intel_ring_offset(rq, cs);
+	assert_ring_tail_valid(rq->ring, rq->tail);
+
+	return cs;
+}
+
+static int mi_flush_dw(struct i915_request *rq, u32 flags)
+{
+	u32 cmd, *cs;
+
+	cs = intel_ring_begin(rq, 4);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	cmd = MI_FLUSH_DW;
+
+	/*
+	 * We always require a command barrier so that subsequent
+	 * commands, such as breadcrumb interrupts, are strictly ordered
+	 * wrt the contents of the write cache being flushed to memory
+	 * (and thus being coherent from the CPU).
+	 */
+	cmd |= MI_FLUSH_DW_STORE_INDEX | MI_FLUSH_DW_OP_STOREDW;
+
+	/*
+	 * Bspec vol 1c.3 - blitter engine command streamer:
+	 * "If ENABLED, all TLBs will be invalidated once the flush
+	 * operation is complete. This bit is only valid when the
+	 * Post-Sync Operation field is a value of 1h or 3h."
+	 */
+	cmd |= flags;
+
+	*cs++ = cmd;
+	*cs++ = HWS_SCRATCH_ADDR | MI_FLUSH_DW_USE_GTT;
+	*cs++ = 0;
+	*cs++ = MI_NOOP;
+
+	intel_ring_advance(rq, cs);
+
+	return 0;
+}
+
+static int gen6_flush_dw(struct i915_request *rq, u32 mode, u32 invflags)
+{
+	return mi_flush_dw(rq, mode & EMIT_INVALIDATE ? invflags : 0);
+}
+
+int gen6_emit_flush_xcs(struct i915_request *rq, u32 mode)
+{
+	return gen6_flush_dw(rq, mode, MI_INVALIDATE_TLB);
+}
+
+int gen6_emit_flush_vcs(struct i915_request *rq, u32 mode)
+{
+	return gen6_flush_dw(rq, mode, MI_INVALIDATE_TLB | MI_INVALIDATE_BSD);
+}
+
+int gen6_emit_bb_start(struct i915_request *rq,
+		       u64 offset, u32 len,
+		       unsigned int dispatch_flags)
+{
+	u32 security;
+	u32 *cs;
+
+	security = MI_BATCH_NON_SECURE_I965;
+	if (dispatch_flags & I915_DISPATCH_SECURE)
+		security = 0;
+
+	cs = intel_ring_begin(rq, 2);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	cs = __gen6_emit_bb_start(cs, offset, security);
+	intel_ring_advance(rq, cs);
+
+	return 0;
+}
+
+int
+hsw_emit_bb_start(struct i915_request *rq,
+		  u64 offset, u32 len,
+		  unsigned int dispatch_flags)
+{
+	u32 security;
+	u32 *cs;
+
+	security = MI_BATCH_PPGTT_HSW | MI_BATCH_NON_SECURE_HSW;
+	if (dispatch_flags & I915_DISPATCH_SECURE)
+		security = 0;
+
+	cs = intel_ring_begin(rq, 2);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	cs = __gen6_emit_bb_start(cs, offset, security);
+	intel_ring_advance(rq, cs);
+
+	return 0;
+}
+
+static int gen7_stall_cs(struct i915_request *rq)
+{
+	u32 *cs;
+
+	cs = intel_ring_begin(rq, 4);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = PIPE_CONTROL_CS_STALL | PIPE_CONTROL_STALL_AT_SCOREBOARD;
+	*cs++ = 0;
+	*cs++ = 0;
+	intel_ring_advance(rq, cs);
+
+	return 0;
+}
+
+int gen7_emit_flush_rcs(struct i915_request *rq, u32 mode)
+{
+	u32 scratch_addr =
+		intel_gt_scratch_offset(rq->engine->gt,
+					INTEL_GT_SCRATCH_FIELD_RENDER_FLUSH);
+	u32 *cs, flags = 0;
+
+	/*
+	 * Ensure that any following seqno writes only happen when the render
+	 * cache is indeed flushed.
+	 *
+	 * Workaround: 4th PIPE_CONTROL command (except the ones with only
+	 * read-cache invalidate bits set) must have the CS_STALL bit set. We
+	 * don't try to be clever and just set it unconditionally.
+	 */
+	flags |= PIPE_CONTROL_CS_STALL;
+
+	/*
+	 * CS_STALL suggests at least a post-sync write.
+	 */
+	flags |= PIPE_CONTROL_QW_WRITE;
+	flags |= PIPE_CONTROL_GLOBAL_GTT_IVB;
+
+	/*
+	 * Just flush everything.  Experiments have shown that reducing the
+	 * number of bits based on the write domains has little performance
+	 * impact.
+	 */
+	if (mode & EMIT_FLUSH) {
+		flags |= PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH;
+		flags |= PIPE_CONTROL_DEPTH_CACHE_FLUSH;
+		flags |= PIPE_CONTROL_DC_FLUSH_ENABLE;
+		flags |= PIPE_CONTROL_FLUSH_ENABLE;
+	}
+	if (mode & EMIT_INVALIDATE) {
+		flags |= PIPE_CONTROL_TLB_INVALIDATE;
+		flags |= PIPE_CONTROL_INSTRUCTION_CACHE_INVALIDATE;
+		flags |= PIPE_CONTROL_TEXTURE_CACHE_INVALIDATE;
+		flags |= PIPE_CONTROL_VF_CACHE_INVALIDATE;
+		flags |= PIPE_CONTROL_CONST_CACHE_INVALIDATE;
+		flags |= PIPE_CONTROL_STATE_CACHE_INVALIDATE;
+		flags |= PIPE_CONTROL_MEDIA_STATE_CLEAR;
+
+		/*
+		 * Workaround: we must issue a pipe_control with CS-stall bit
+		 * set before a pipe_control command that has the state cache
+		 * invalidate bit set.
+		 */
+		gen7_stall_cs(rq);
+	}
+
+	cs = intel_ring_begin(rq, 4);
+	if (IS_ERR(cs))
+		return PTR_ERR(cs);
+
+	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = flags;
+	*cs++ = scratch_addr;
+	*cs++ = 0;
+	intel_ring_advance(rq, cs);
+
+	return 0;
+}
+
+u32 *gen7_emit_breadcrumb_rcs(struct i915_request *rq, u32 *cs)
+{
+	*cs++ = GFX_OP_PIPE_CONTROL(4);
+	*cs++ = (PIPE_CONTROL_RENDER_TARGET_CACHE_FLUSH |
+		 PIPE_CONTROL_DEPTH_CACHE_FLUSH |
+		 PIPE_CONTROL_DC_FLUSH_ENABLE |
+		 PIPE_CONTROL_FLUSH_ENABLE |
+		 PIPE_CONTROL_QW_WRITE |
+		 PIPE_CONTROL_GLOBAL_GTT_IVB |
+		 PIPE_CONTROL_CS_STALL);
+	*cs++ = i915_request_active_timeline(rq)->hwsp_offset;
+	*cs++ = rq->fence.seqno;
+
+	*cs++ = MI_USER_INTERRUPT;
+	*cs++ = MI_NOOP;
+
+	rq->tail = intel_ring_offset(rq, cs);
+	assert_ring_tail_valid(rq->ring, rq->tail);
+
+	return cs;
+}
+
+u32 *gen6_emit_breadcrumb_xcs(struct i915_request *rq, u32 *cs)
+{
+	GEM_BUG_ON(i915_request_active_timeline(rq)->hwsp_ggtt != rq->engine->status_page.vma);
+	GEM_BUG_ON(offset_in_page(i915_request_active_timeline(rq)->hwsp_offset) != I915_GEM_HWS_SEQNO_ADDR);
+
+	*cs++ = MI_FLUSH_DW | MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+	*cs++ = I915_GEM_HWS_SEQNO_ADDR | MI_FLUSH_DW_USE_GTT;
+	*cs++ = rq->fence.seqno;
+
+	*cs++ = MI_USER_INTERRUPT;
+
+	rq->tail = intel_ring_offset(rq, cs);
+	assert_ring_tail_valid(rq->ring, rq->tail);
+
+	return cs;
+}
+
+#define GEN7_XCS_WA 32
+u32 *gen7_emit_breadcrumb_xcs(struct i915_request *rq, u32 *cs)
+{
+	int i;
+
+	GEM_BUG_ON(i915_request_active_timeline(rq)->hwsp_ggtt != rq->engine->status_page.vma);
+	GEM_BUG_ON(offset_in_page(i915_request_active_timeline(rq)->hwsp_offset) != I915_GEM_HWS_SEQNO_ADDR);
+
+	*cs++ = MI_FLUSH_DW | MI_INVALIDATE_TLB |
+		MI_FLUSH_DW_OP_STOREDW | MI_FLUSH_DW_STORE_INDEX;
+	*cs++ = I915_GEM_HWS_SEQNO_ADDR | MI_FLUSH_DW_USE_GTT;
+	*cs++ = rq->fence.seqno;
+
+	for (i = 0; i < GEN7_XCS_WA; i++) {
+		*cs++ = MI_STORE_DWORD_INDEX;
+		*cs++ = I915_GEM_HWS_SEQNO_ADDR;
+		*cs++ = rq->fence.seqno;
+	}
+
+	*cs++ = MI_FLUSH_DW;
+	*cs++ = 0;
+	*cs++ = 0;
+
+	*cs++ = MI_USER_INTERRUPT;
+	*cs++ = MI_NOOP;
+
+	rq->tail = intel_ring_offset(rq, cs);
+	assert_ring_tail_valid(rq->ring, rq->tail);
+
+	return cs;
+}
+#undef GEN7_XCS_WA
+
+void gen6_irq_enable(struct intel_engine_cs *engine)
+{
+	ENGINE_WRITE(engine, RING_IMR,
+		     ~(engine->irq_enable_mask | engine->irq_keep_mask));
+
+	/* Flush/delay to ensure the RING_IMR is active before the GT IMR */
+	ENGINE_POSTING_READ(engine, RING_IMR);
+
+	gen5_gt_enable_irq(engine->gt, engine->irq_enable_mask);
+}
+
+void gen6_irq_disable(struct intel_engine_cs *engine)
+{
+	ENGINE_WRITE(engine, RING_IMR, ~engine->irq_keep_mask);
+	gen5_gt_disable_irq(engine->gt, engine->irq_enable_mask);
+}
+
+void hsw_irq_enable_vecs(struct intel_engine_cs *engine)
+{
+	ENGINE_WRITE(engine, RING_IMR, ~engine->irq_enable_mask);
+
+	/* Flush/delay to ensure the RING_IMR is active before the GT IMR */
+	ENGINE_POSTING_READ(engine, RING_IMR);
+
+	gen6_gt_pm_unmask_irq(engine->gt, engine->irq_enable_mask);
+}
+
+void hsw_irq_disable_vecs(struct intel_engine_cs *engine)
+{
+	ENGINE_WRITE(engine, RING_IMR, ~0);
+	gen6_gt_pm_mask_irq(engine->gt, engine->irq_enable_mask);
+}