diff mbox series

drm/i915: Engine relative MMIO

Message ID 20190330001045.4850-1-John.C.Harrison@Intel.com (mailing list archive)
State New, archived
Headers show
Series drm/i915: Engine relative MMIO | expand

Commit Message

John Harrison March 30, 2019, 12:10 a.m. UTC
From: John Harrison <John.C.Harrison@Intel.com>

With virtual engines, it is no longer possible to know which specific
physical engine a given request will be executed on at the time that
request is generated. This means that the request itself must be engine
agnostic - any direct register writes must be relative to the engine
and not absolute addresses.

The LRI command has support for engine relative addressing. However,
the mechanism is not transparent to the driver. The scheme for Gen11
(MI_LRI_ADD_CS_MMIO_START) requires the LRI address to have no
absolute engine base component. The hardware then adds on the correct
engine offset at execution time.

Due to the non-trivial and differing schemes on different hardware, it
is not possible to simply update the code that creates the LRI
commands to set a remap flag and let the hardware get on with it.
Instead, this patch adds function wrappers for generating the LRI
command itself and then for constructing the correct address to use
with the LRI.

v2: Fix build break in GVT. Remove flags parameter [review feedback
from Chris W].

v3: Fix build break in selftest. Rebase to newer base tree and fix
merge conflict.

Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
---
 drivers/gpu/drm/i915/gvt/mmio_context.c       | 16 +++-
 drivers/gpu/drm/i915/i915_cmd_parser.c        |  4 +-
 drivers/gpu/drm/i915/i915_gem_context.c       | 12 +--
 drivers/gpu/drm/i915/i915_gem_execbuffer.c    |  4 +-
 drivers/gpu/drm/i915/i915_perf.c              | 19 +++--
 drivers/gpu/drm/i915/intel_engine_cs.c        | 11 +++
 drivers/gpu/drm/i915/intel_gpu_commands.h     |  6 +-
 drivers/gpu/drm/i915/intel_lrc.c              | 80 ++++++++++---------
 drivers/gpu/drm/i915/intel_lrc_reg.h          |  4 +-
 drivers/gpu/drm/i915/intel_mocs.c             | 17 ++--
 drivers/gpu/drm/i915/intel_ringbuffer.c       | 45 +++++++++--
 drivers/gpu/drm/i915/intel_ringbuffer.h       |  4 +
 drivers/gpu/drm/i915/intel_workarounds.c      |  4 +-
 .../drm/i915/selftests/intel_workarounds.c    |  9 ++-
 14 files changed, 154 insertions(+), 81 deletions(-)

Comments

Chris Wilson March 30, 2019, 7:59 a.m. UTC | #1
Quoting John.C.Harrison@Intel.com (2019-03-30 00:10:45)
> From: John Harrison <John.C.Harrison@Intel.com>
> 
> With virtual engines, it is no longer possible to know which specific
> physical engine a given request will be executed on at the time that
> request is generated. This means that the request itself must be engine
> agnostic - any direct register writes must be relative to the engine
> and not absolute addresses.
> 
> The LRI command has support for engine relative addressing. However,
> the mechanism is not transparent to the driver. The scheme for Gen11
> (MI_LRI_ADD_CS_MMIO_START) requires the LRI address to have no
> absolute engine base component. The hardware then adds on the correct
> engine offset at execution time.
> 
> Due to the non-trivial and differing schemes on different hardware, it
> is not possible to simply update the code that creates the LRI
> commands to set a remap flag and let the hardware get on with it.
> Instead, this patch adds function wrappers for generating the LRI
> command itself and then for constructing the correct address to use
> with the LRI.
> 
> v2: Fix build break in GVT. Remove flags parameter [review feedback
> from Chris W].

I'm still asking why are we "changing" instructions that we know are tied
to an engine? The instruction is the same, it just gained an extra bit
to denote relative mmio offset.
-Chris
John Harrison April 1, 2019, 9:02 p.m. UTC | #2
On 3/30/2019 00:59, Chris Wilson wrote:
> Quoting John.C.Harrison@Intel.com (2019-03-30 00:10:45)
>> From: John Harrison <John.C.Harrison@Intel.com>
>>
>> With virtual engines, it is no longer possible to know which specific
>> physical engine a given request will be executed on at the time that
>> request is generated. This means that the request itself must be engine
>> agnostic - any direct register writes must be relative to the engine
>> and not absolute addresses.
>>
>> The LRI command has support for engine relative addressing. However,
>> the mechanism is not transparent to the driver. The scheme for Gen11
>> (MI_LRI_ADD_CS_MMIO_START) requires the LRI address to have no
>> absolute engine base component. The hardware then adds on the correct
>> engine offset at execution time.
>>
>> Due to the non-trivial and differing schemes on different hardware, it
>> is not possible to simply update the code that creates the LRI
>> commands to set a remap flag and let the hardware get on with it.
>> Instead, this patch adds function wrappers for generating the LRI
>> command itself and then for constructing the correct address to use
>> with the LRI.
>>
>> v2: Fix build break in GVT. Remove flags parameter [review feedback
>> from Chris W].
> I'm still asking why are we "changing" instructions that we know are tied
> to an engine? The instruction is the same, it just gained an extra bit
> to denote relative mmio offset.
> -Chris

I'm not sure that I understand your question. It's not really an option 
to just add the extra bit wherever an LRI is used on account of the 
decision of which bit to add is complex. Also, it's not just the LRI 
command that needs to change but the address used within the LRI too. 
And it is only getting more complex in the future. Rather than add all 
that extra code to each LRI instance, it is far simpler to add a helper 
function for generating the LRI.

John.
Chris Wilson April 1, 2019, 9:10 p.m. UTC | #3
Quoting John Harrison (2019-04-01 22:02:07)
> On 3/30/2019 00:59, Chris Wilson wrote:
> > Quoting John.C.Harrison@Intel.com (2019-03-30 00:10:45)
> >> From: John Harrison <John.C.Harrison@Intel.com>
> >>
> >> With virtual engines, it is no longer possible to know which specific
> >> physical engine a given request will be executed on at the time that
> >> request is generated. This means that the request itself must be engine
> >> agnostic - any direct register writes must be relative to the engine
> >> and not absolute addresses.
> >>
> >> The LRI command has support for engine relative addressing. However,
> >> the mechanism is not transparent to the driver. The scheme for Gen11
> >> (MI_LRI_ADD_CS_MMIO_START) requires the LRI address to have no
> >> absolute engine base component. The hardware then adds on the correct
> >> engine offset at execution time.
> >>
> >> Due to the non-trivial and differing schemes on different hardware, it
> >> is not possible to simply update the code that creates the LRI
> >> commands to set a remap flag and let the hardware get on with it.
> >> Instead, this patch adds function wrappers for generating the LRI
> >> command itself and then for constructing the correct address to use
> >> with the LRI.
> >>
> >> v2: Fix build break in GVT. Remove flags parameter [review feedback
> >> from Chris W].
> > I'm still asking why are we "changing" instructions that we know are tied
> > to an engine? The instruction is the same, it just gained an extra bit
> > to denote relative mmio offset.
> > -Chris
> 
> I'm not sure that I understand your question. It's not really an option 
> to just add the extra bit wherever an LRI is used on account of the 
> decision of which bit to add is complex. Also, it's not just the LRI 
> command that needs to change but the address used within the LRI too. 
> And it is only getting more complex in the future. Rather than add all 
> that extra code to each LRI instance, it is far simpler to add a helper 
> function for generating the LRI.

I disagree that adding complexity and obfuscation to old platforms is
simpler. I disagree that it makes any sense to add those options to paths
that are explicitly targeting a physical engine. That whittles it down to
intel_lrc.c.
-Chris
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/gvt/mmio_context.c b/drivers/gpu/drm/i915/gvt/mmio_context.c
index 76630fbe51b6..1d24095b345a 100644
--- a/drivers/gpu/drm/i915/gvt/mmio_context.c
+++ b/drivers/gpu/drm/i915/gvt/mmio_context.c
@@ -199,14 +199,14 @@  restore_context_mmio_for_inhibit(struct intel_vgpu *vgpu,
 	if (IS_ERR(cs))
 		return PTR_ERR(cs);
 
-	*cs++ = MI_LOAD_REGISTER_IMM(count);
+	*cs++ = i915_get_lri_cmd(req->engine, count);
 	for (mmio = gvt->engine_mmio_list.mmio;
 	     i915_mmio_reg_valid(mmio->reg); mmio++) {
 		if (mmio->ring_id != ring_id ||
 		    !mmio->in_context)
 			continue;
 
-		*cs++ = i915_mmio_reg_offset(mmio->reg);
+		*cs++ = i915_get_lri_reg(req->engine, mmio->reg);
 		*cs++ = vgpu_vreg_t(vgpu, mmio->reg) |
 				(mmio->mask << 16);
 		gvt_dbg_core("add lri reg pair 0x%x:0x%x in inhibit ctx, vgpu:%d, rind_id:%d\n",
@@ -234,7 +234,11 @@  restore_render_mocs_control_for_inhibit(struct intel_vgpu *vgpu,
 	if (IS_ERR(cs))
 		return PTR_ERR(cs);
 
-	*cs++ = MI_LOAD_REGISTER_IMM(GEN9_MOCS_SIZE);
+	/*
+	 * GEN9_GFX_MOCS is not engine relative, therefore there is no
+	 * need for relative addressing.
+	 */
+	*cs++ = __MI_LOAD_REGISTER_IMM(GEN9_MOCS_SIZE);
 
 	for (index = 0; index < GEN9_MOCS_SIZE; index++) {
 		*cs++ = i915_mmio_reg_offset(GEN9_GFX_MOCS(index));
@@ -261,7 +265,11 @@  restore_render_mocs_l3cc_for_inhibit(struct intel_vgpu *vgpu,
 	if (IS_ERR(cs))
 		return PTR_ERR(cs);
 
-	*cs++ = MI_LOAD_REGISTER_IMM(GEN9_MOCS_SIZE / 2);
+	/*
+	 * GEN9_LNCFCMOCS is not engine relative, therefore there is no
+	 * need for relative addressing.
+	 */
+	*cs++ = __MI_LOAD_REGISTER_IMM(GEN9_MOCS_SIZE / 2);
 
 	for (index = 0; index < GEN9_MOCS_SIZE / 2; index++) {
 		*cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(index));
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 503d548a55f7..91ebe18aacc6 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -220,7 +220,7 @@  static const struct drm_i915_cmd_descriptor common_cmds[] = {
 	CMD(  MI_SUSPEND_FLUSH,                 SMI,    F,  1,      S  ),
 	CMD(  MI_SEMAPHORE_MBOX,                SMI,   !F,  0xFF,   R  ),
 	CMD(  MI_STORE_DWORD_INDEX,             SMI,   !F,  0xFF,   R  ),
-	CMD(  MI_LOAD_REGISTER_IMM(1),          SMI,   !F,  0xFF,   W,
+	CMD(  __MI_LOAD_REGISTER_IMM(1),        SMI,   !F,  0xFF,   W,
 	      .reg = { .offset = 1, .mask = 0x007FFFFC, .step = 2 }    ),
 	CMD(  MI_STORE_REGISTER_MEM,            SMI,    F,  3,     W | B,
 	      .reg = { .offset = 1, .mask = 0x007FFFFC },
@@ -1182,7 +1182,7 @@  static bool check_cmd(const struct intel_engine_cs *engine,
 					return false;
 				}
 
-				if (desc->cmd.value == MI_LOAD_REGISTER_IMM(1) &&
+				if (desc->cmd.value == __MI_LOAD_REGISTER_IMM(1) &&
 				    (offset + 2 > length ||
 				     (cmd[offset + 1] & reg->mask) != reg->value)) {
 					DRM_DEBUG_DRIVER("CMD: Rejected LRI to masked register 0x%08X\n",
diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
index 662da485e15f..8bba3640059a 100644
--- a/drivers/gpu/drm/i915/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/i915_gem_context.c
@@ -1038,11 +1038,11 @@  static int emit_ppgtt_update(struct i915_request *rq, void *data)
 		if (IS_ERR(cs))
 			return PTR_ERR(cs);
 
-		*cs++ = MI_LOAD_REGISTER_IMM(2);
+		*cs++ = i915_get_lri_cmd(engine, 2);
 
-		*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(engine, 0));
+		*cs++ = i915_get_lri_reg(engine, GEN8_RING_PDP_UDW(engine, 0));
 		*cs++ = upper_32_bits(pd_daddr);
-		*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(engine, 0));
+		*cs++ = i915_get_lri_reg(engine, GEN8_RING_PDP_LDW(engine, 0));
 		*cs++ = lower_32_bits(pd_daddr);
 
 		*cs++ = MI_NOOP;
@@ -1052,13 +1052,13 @@  static int emit_ppgtt_update(struct i915_request *rq, void *data)
 		if (IS_ERR(cs))
 			return PTR_ERR(cs);
 
-		*cs++ = MI_LOAD_REGISTER_IMM(2 * GEN8_3LVL_PDPES);
+		*cs++ = i915_get_lri_cmd(engine, 2 * GEN8_3LVL_PDPES);
 		for (i = GEN8_3LVL_PDPES; i--; ) {
 			const dma_addr_t pd_daddr = i915_page_dir_dma_addr(ppgtt, i);
 
-			*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(engine, i));
+			*cs++ = i915_get_lri_reg(engine, GEN8_RING_PDP_UDW(engine, i));
 			*cs++ = upper_32_bits(pd_daddr);
-			*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(engine, i));
+			*cs++ = i915_get_lri_reg(engine, GEN8_RING_PDP_LDW(engine, i));
 			*cs++ = lower_32_bits(pd_daddr);
 		}
 		*cs++ = MI_NOOP;
diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
index 3d672c9edb94..bd602b6261ed 100644
--- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
@@ -1965,9 +1965,9 @@  static int i915_reset_gen7_sol_offsets(struct i915_request *rq)
 	if (IS_ERR(cs))
 		return PTR_ERR(cs);
 
-	*cs++ = MI_LOAD_REGISTER_IMM(4);
+	*cs++ = i915_get_lri_cmd(rq->engine, 4);
 	for (i = 0; i < 4; i++) {
-		*cs++ = i915_mmio_reg_offset(GEN7_SO_WRITE_OFFSET(i));
+		*cs++ = i915_get_lri_reg(rq->engine, GEN7_SO_WRITE_OFFSET(i));
 		*cs++ = 0;
 	}
 	*cs++ = MI_NOOP;
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c
index 39a4804091d7..10d5ab991908 100644
--- a/drivers/gpu/drm/i915/i915_perf.c
+++ b/drivers/gpu/drm/i915/i915_perf.c
@@ -1628,7 +1628,8 @@  static void hsw_disable_metric_set(struct drm_i915_private *dev_priv)
  * in the case that the OA unit has been disabled.
  */
 static void
-gen8_update_reg_state_unlocked(struct intel_context *ce,
+gen8_update_reg_state_unlocked(struct intel_engine_cs *engine,
+			       struct intel_context *ce,
 			       u32 *reg_state,
 			       const struct i915_oa_config *oa_config)
 {
@@ -1647,7 +1648,12 @@  gen8_update_reg_state_unlocked(struct intel_context *ce,
 	};
 	int i;
 
-	CTX_REG(reg_state, ctx_oactxctrl, GEN8_OACTXCONTROL,
+	/*
+	 * NB: The LRI instruction is generated by the hardware.
+	 * Should we read it in and assert that the offset flag is set?
+	 */
+
+	CTX_REG(engine, reg_state, ctx_oactxctrl, GEN8_OACTXCONTROL,
 		(i915->perf.oa.period_exponent << GEN8_OA_TIMER_PERIOD_SHIFT) |
 		(i915->perf.oa.periodic ? GEN8_OA_TIMER_ENABLE : 0) |
 		GEN8_OA_COUNTER_RESUME);
@@ -1674,10 +1680,10 @@  gen8_update_reg_state_unlocked(struct intel_context *ce,
 			}
 		}
 
-		CTX_REG(reg_state, state_offset, flex_regs[i], value);
+		CTX_REG(engine, reg_state, state_offset, flex_regs[i], value);
 	}
 
-	CTX_REG(reg_state,
+	CTX_REG(engine, reg_state,
 		CTX_R_PWR_CLK_STATE, GEN8_R_PWR_CLK_STATE,
 		gen8_make_rpcs(i915, &ce->sseu));
 }
@@ -1752,7 +1758,7 @@  static int gen8_configure_all_contexts(struct drm_i915_private *dev_priv,
 		ce->state->obj->mm.dirty = true;
 		regs += LRC_STATE_PN * PAGE_SIZE / sizeof(*regs);
 
-		gen8_update_reg_state_unlocked(ce, regs, oa_config);
+		gen8_update_reg_state_unlocked(engine, ce, regs, oa_config);
 
 		i915_gem_object_unpin_map(ce->state->obj);
 	}
@@ -2146,7 +2152,8 @@  void i915_oa_init_reg_state(struct intel_engine_cs *engine,
 
 	stream = engine->i915->perf.oa.exclusive_stream;
 	if (stream)
-		gen8_update_reg_state_unlocked(ce, regs, stream->oa_config);
+		gen8_update_reg_state_unlocked(engine, ce, regs,
+					       stream->oa_config);
 }
 
 /**
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index d0427c2e3997..0b5580b19d3d 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -246,6 +246,17 @@  static u32 __engine_mmio_base(struct drm_i915_private *i915,
 	return bases[i].base;
 }
 
+bool i915_engine_has_relative_lri(const struct intel_engine_cs *engine)
+{
+	if (INTEL_GEN(engine->i915) < 11)
+		return false;
+
+	if (engine->id == BCS0)
+		return false;
+
+	return true;
+}
+
 static void __sprint_engine_name(char *name, const struct engine_info *info)
 {
 	WARN_ON(snprintf(name, INTEL_ENGINE_CS_MAX_NAME, "%s%u",
diff --git a/drivers/gpu/drm/i915/intel_gpu_commands.h b/drivers/gpu/drm/i915/intel_gpu_commands.h
index a34ece53a771..97c2cfd1d38f 100644
--- a/drivers/gpu/drm/i915/intel_gpu_commands.h
+++ b/drivers/gpu/drm/i915/intel_gpu_commands.h
@@ -123,9 +123,13 @@ 
  *   simply ignores the register load under certain conditions.
  * - One can actually load arbitrary many arbitrary registers: Simply issue x
  *   address/value pairs. Don't overdue it, though, x <= 2^4 must hold!
+ * - Newer hardware supports engine relative addresses but older hardware does
+ *   not. So never call MI_LRI directly, always use the i915_get_lri_cmd()
+ *   and i915_get_lri_reg() helper functions.
  */
-#define MI_LOAD_REGISTER_IMM(x)	MI_INSTR(0x22, 2*(x)-1)
+#define __MI_LOAD_REGISTER_IMM(x)	MI_INSTR(0x22, 2*(x)-1)
 #define   MI_LRI_FORCE_POSTED		(1<<12)
+#define   MI_LRI_ADD_CS_MMIO_START	(1<<19)
 #define MI_STORE_REGISTER_MEM        MI_INSTR(0x24, 1)
 #define MI_STORE_REGISTER_MEM_GEN8   MI_INSTR(0x24, 2)
 #define   MI_SRM_LRM_GLOBAL_GTT		(1<<22)
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index bec232acc8d7..b658f9d77d25 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -1448,13 +1448,14 @@  static int emit_pdps(struct i915_request *rq)
 		return PTR_ERR(cs);
 
 	/* Ensure the LRI have landed before we invalidate & continue */
-	*cs++ = MI_LOAD_REGISTER_IMM(2 * GEN8_3LVL_PDPES) | MI_LRI_FORCE_POSTED;
+	*cs++ = i915_get_lri_cmd(engine, 2 * GEN8_3LVL_PDPES) |
+				 MI_LRI_FORCE_POSTED;
 	for (i = GEN8_3LVL_PDPES; i--; ) {
 		const dma_addr_t pd_daddr = i915_page_dir_dma_addr(ppgtt, i);
 
-		*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_UDW(engine, i));
+		*cs++ = i915_get_lri_reg(engine, GEN8_RING_PDP_UDW(engine, i));
 		*cs++ = upper_32_bits(pd_daddr);
-		*cs++ = i915_mmio_reg_offset(GEN8_RING_PDP_LDW(engine, i));
+		*cs++ = i915_get_lri_reg(engine, GEN8_RING_PDP_LDW(engine, i));
 		*cs++ = lower_32_bits(pd_daddr);
 	}
 	*cs++ = MI_NOOP;
@@ -1528,8 +1529,8 @@  gen8_emit_flush_coherentl3_wa(struct intel_engine_cs *engine, u32 *batch)
 	*batch++ = i915_scratch_offset(engine->i915) + 256;
 	*batch++ = 0;
 
-	*batch++ = MI_LOAD_REGISTER_IMM(1);
-	*batch++ = i915_mmio_reg_offset(GEN8_L3SQCREG4);
+	*batch++ = i915_get_lri_cmd(engine, 1);
+	*batch++ = i915_get_lri_reg(engine, GEN8_L3SQCREG4);
 	*batch++ = 0x40400000 | GEN8_LQSC_FLUSH_COHERENT_LINES;
 
 	batch = gen8_emit_pipe_control(batch,
@@ -1599,13 +1600,14 @@  struct lri {
 	u32 value;
 };
 
-static u32 *emit_lri(u32 *batch, const struct lri *lri, unsigned int count)
+static u32 *emit_lri(struct intel_engine_cs *engine, u32 *batch,
+		     const struct lri *lri, unsigned int count)
 {
 	GEM_BUG_ON(!count || count > 63);
 
-	*batch++ = MI_LOAD_REGISTER_IMM(count);
+	*batch++ = i915_get_lri_cmd(engine, count);
 	do {
-		*batch++ = i915_mmio_reg_offset(lri->reg);
+		*batch++ = i915_get_lri_reg(engine, lri->reg);
 		*batch++ = lri->value;
 	} while (lri++, --count);
 	*batch++ = MI_NOOP;
@@ -1643,7 +1645,7 @@  static u32 *gen9_init_indirectctx_bb(struct intel_engine_cs *engine, u32 *batch)
 	/* WaFlushCoherentL3CacheLinesAtContextSwitch:skl,bxt,glk */
 	batch = gen8_emit_flush_coherentl3_wa(engine, batch);
 
-	batch = emit_lri(batch, lri, ARRAY_SIZE(lri));
+	batch = emit_lri(engine, batch, lri, ARRAY_SIZE(lri));
 
 	/* WaMediaPoolStateCmdInWABB:bxt,glk */
 	if (HAS_POOLED_EU(engine->i915)) {
@@ -2655,10 +2657,10 @@  static void execlists_init_reg_state(u32 *regs,
 	 * values (including all the missing MI_LOAD_REGISTER_IMM commands that
 	 * we are not initializing here).
 	 */
-	regs[CTX_LRI_HEADER_0] = MI_LOAD_REGISTER_IMM(rcs ? 14 : 11) |
-				 MI_LRI_FORCE_POSTED;
+	regs[CTX_LRI_HEADER_0] = i915_get_lri_cmd(engine, rcs ? 14 : 11) |
+						  MI_LRI_FORCE_POSTED;
 
-	CTX_REG(regs, CTX_CONTEXT_CONTROL, RING_CONTEXT_CONTROL(base),
+	CTX_REG(engine, regs, CTX_CONTEXT_CONTROL, RING_CONTEXT_CONTROL(base),
 		_MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT) |
 		_MASKED_BIT_ENABLE(CTX_CTRL_INHIBIT_SYN_CTX_SWITCH));
 	if (INTEL_GEN(engine->i915) < 11) {
@@ -2666,22 +2668,23 @@  static void execlists_init_reg_state(u32 *regs,
 			_MASKED_BIT_DISABLE(CTX_CTRL_ENGINE_CTX_SAVE_INHIBIT |
 					    CTX_CTRL_RS_CTX_ENABLE);
 	}
-	CTX_REG(regs, CTX_RING_HEAD, RING_HEAD(base), 0);
-	CTX_REG(regs, CTX_RING_TAIL, RING_TAIL(base), 0);
-	CTX_REG(regs, CTX_RING_BUFFER_START, RING_START(base), 0);
-	CTX_REG(regs, CTX_RING_BUFFER_CONTROL, RING_CTL(base),
+	CTX_REG(engine, regs, CTX_RING_HEAD, RING_HEAD(base), 0);
+	CTX_REG(engine, regs, CTX_RING_TAIL, RING_TAIL(base), 0);
+	CTX_REG(engine, regs, CTX_RING_BUFFER_START, RING_START(base), 0);
+	CTX_REG(engine, regs, CTX_RING_BUFFER_CONTROL, RING_CTL(base),
 		RING_CTL_SIZE(ring->size) | RING_VALID);
-	CTX_REG(regs, CTX_BB_HEAD_U, RING_BBADDR_UDW(base), 0);
-	CTX_REG(regs, CTX_BB_HEAD_L, RING_BBADDR(base), 0);
-	CTX_REG(regs, CTX_BB_STATE, RING_BBSTATE(base), RING_BB_PPGTT);
-	CTX_REG(regs, CTX_SECOND_BB_HEAD_U, RING_SBBADDR_UDW(base), 0);
-	CTX_REG(regs, CTX_SECOND_BB_HEAD_L, RING_SBBADDR(base), 0);
-	CTX_REG(regs, CTX_SECOND_BB_STATE, RING_SBBSTATE(base), 0);
+	CTX_REG(engine, regs, CTX_BB_HEAD_U, RING_BBADDR_UDW(base), 0);
+	CTX_REG(engine, regs, CTX_BB_HEAD_L, RING_BBADDR(base), 0);
+	CTX_REG(engine, regs, CTX_BB_STATE, RING_BBSTATE(base), RING_BB_PPGTT);
+	CTX_REG(engine, regs, CTX_SECOND_BB_HEAD_U, RING_SBBADDR_UDW(base), 0);
+	CTX_REG(engine, regs, CTX_SECOND_BB_HEAD_L, RING_SBBADDR(base), 0);
+	CTX_REG(engine, regs, CTX_SECOND_BB_STATE, RING_SBBSTATE(base), 0);
 	if (rcs) {
 		struct i915_ctx_workarounds *wa_ctx = &engine->wa_ctx;
 
-		CTX_REG(regs, CTX_RCS_INDIRECT_CTX, RING_INDIRECT_CTX(base), 0);
-		CTX_REG(regs, CTX_RCS_INDIRECT_CTX_OFFSET,
+		CTX_REG(engine, regs, CTX_RCS_INDIRECT_CTX,
+			RING_INDIRECT_CTX(base), 0);
+		CTX_REG(engine, regs, CTX_RCS_INDIRECT_CTX_OFFSET,
 			RING_INDIRECT_CTX_OFFSET(base), 0);
 		if (wa_ctx->indirect_ctx.size) {
 			u32 ggtt_offset = i915_ggtt_offset(wa_ctx->vma);
@@ -2694,7 +2697,8 @@  static void execlists_init_reg_state(u32 *regs,
 				intel_lr_indirect_ctx_offset(engine) << 6;
 		}
 
-		CTX_REG(regs, CTX_BB_PER_CTX_PTR, RING_BB_PER_CTX_PTR(base), 0);
+		CTX_REG(engine, regs, CTX_BB_PER_CTX_PTR,
+			RING_BB_PER_CTX_PTR(base), 0);
 		if (wa_ctx->per_ctx.size) {
 			u32 ggtt_offset = i915_ggtt_offset(wa_ctx->vma);
 
@@ -2703,18 +2707,19 @@  static void execlists_init_reg_state(u32 *regs,
 		}
 	}
 
-	regs[CTX_LRI_HEADER_1] = MI_LOAD_REGISTER_IMM(9) | MI_LRI_FORCE_POSTED;
+	regs[CTX_LRI_HEADER_1] = i915_get_lri_cmd(engine, 9) |
+						  MI_LRI_FORCE_POSTED;
 
-	CTX_REG(regs, CTX_CTX_TIMESTAMP, RING_CTX_TIMESTAMP(base), 0);
+	CTX_REG(engine, regs, CTX_CTX_TIMESTAMP, RING_CTX_TIMESTAMP(base), 0);
 	/* PDP values well be assigned later if needed */
-	CTX_REG(regs, CTX_PDP3_UDW, GEN8_RING_PDP_UDW(engine, 3), 0);
-	CTX_REG(regs, CTX_PDP3_LDW, GEN8_RING_PDP_LDW(engine, 3), 0);
-	CTX_REG(regs, CTX_PDP2_UDW, GEN8_RING_PDP_UDW(engine, 2), 0);
-	CTX_REG(regs, CTX_PDP2_LDW, GEN8_RING_PDP_LDW(engine, 2), 0);
-	CTX_REG(regs, CTX_PDP1_UDW, GEN8_RING_PDP_UDW(engine, 1), 0);
-	CTX_REG(regs, CTX_PDP1_LDW, GEN8_RING_PDP_LDW(engine, 1), 0);
-	CTX_REG(regs, CTX_PDP0_UDW, GEN8_RING_PDP_UDW(engine, 0), 0);
-	CTX_REG(regs, CTX_PDP0_LDW, GEN8_RING_PDP_LDW(engine, 0), 0);
+	CTX_REG(engine, regs, CTX_PDP3_UDW, GEN8_RING_PDP_UDW(engine, 3), 0);
+	CTX_REG(engine, regs, CTX_PDP3_LDW, GEN8_RING_PDP_LDW(engine, 3), 0);
+	CTX_REG(engine, regs, CTX_PDP2_UDW, GEN8_RING_PDP_UDW(engine, 2), 0);
+	CTX_REG(engine, regs, CTX_PDP2_LDW, GEN8_RING_PDP_LDW(engine, 2), 0);
+	CTX_REG(engine, regs, CTX_PDP1_UDW, GEN8_RING_PDP_UDW(engine, 1), 0);
+	CTX_REG(engine, regs, CTX_PDP1_LDW, GEN8_RING_PDP_LDW(engine, 1), 0);
+	CTX_REG(engine, regs, CTX_PDP0_UDW, GEN8_RING_PDP_UDW(engine, 0), 0);
+	CTX_REG(engine, regs, CTX_PDP0_LDW, GEN8_RING_PDP_LDW(engine, 0), 0);
 
 	if (i915_vm_is_4lvl(&ppgtt->vm)) {
 		/* 64b PPGTT (48bit canonical)
@@ -2730,8 +2735,9 @@  static void execlists_init_reg_state(u32 *regs,
 	}
 
 	if (rcs) {
-		regs[CTX_LRI_HEADER_2] = MI_LOAD_REGISTER_IMM(1);
-		CTX_REG(regs, CTX_R_PWR_CLK_STATE, GEN8_R_PWR_CLK_STATE, 0);
+		regs[CTX_LRI_HEADER_2] = i915_get_lri_cmd(engine, 1);
+		CTX_REG(engine, regs, CTX_R_PWR_CLK_STATE,
+			GEN8_R_PWR_CLK_STATE, 0);
 
 		i915_oa_init_reg_state(engine, ce, regs);
 	}
diff --git a/drivers/gpu/drm/i915/intel_lrc_reg.h b/drivers/gpu/drm/i915/intel_lrc_reg.h
index 5ef932d810a7..40b1142d0d74 100644
--- a/drivers/gpu/drm/i915/intel_lrc_reg.h
+++ b/drivers/gpu/drm/i915/intel_lrc_reg.h
@@ -39,10 +39,10 @@ 
 #define CTX_R_PWR_CLK_STATE		0x42
 #define CTX_END				0x44
 
-#define CTX_REG(reg_state, pos, reg, val) do { \
+#define CTX_REG(engine, reg_state, pos, reg, val) do { \
 	u32 *reg_state__ = (reg_state); \
 	const u32 pos__ = (pos); \
-	(reg_state__)[(pos__) + 0] = i915_mmio_reg_offset(reg); \
+	(reg_state__)[(pos__) + 0] = i915_get_lri_reg((engine), (reg)); \
 	(reg_state__)[(pos__) + 1] = (val); \
 } while (0)
 
diff --git a/drivers/gpu/drm/i915/intel_mocs.c b/drivers/gpu/drm/i915/intel_mocs.c
index 274ba78500c0..bb11d0f68bba 100644
--- a/drivers/gpu/drm/i915/intel_mocs.c
+++ b/drivers/gpu/drm/i915/intel_mocs.c
@@ -322,9 +322,6 @@  static u32 get_entry_control(const struct drm_i915_mocs_table *table,
 /**
  * intel_mocs_init_engine() - emit the mocs control table
  * @engine:	The engine for whom to emit the registers.
- *
- * This function simply emits a MI_LOAD_REGISTER_IMM command for the
- * given table starting at the given address.
  */
 void intel_mocs_init_engine(struct intel_engine_cs *engine)
 {
@@ -378,18 +375,20 @@  static int emit_mocs_control_table(struct i915_request *rq,
 	if (IS_ERR(cs))
 		return PTR_ERR(cs);
 
-	*cs++ = MI_LOAD_REGISTER_IMM(table->n_entries);
+	*cs++ = i915_get_lri_cmd(rq->engine, table->n_entries);
 
 	for (index = 0; index < table->size; index++) {
 		u32 value = get_entry_control(table, index);
 
-		*cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
+		*cs++ = i915_get_lri_reg(rq->engine,
+					 mocs_register(engine, index));
 		*cs++ = value;
 	}
 
 	/* All remaining entries are also unused */
 	for (; index < table->n_entries; index++) {
-		*cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
+		*cs++ = i915_get_lri_reg(rq->engine,
+					 mocs_register(engine, index));
 		*cs++ = unused_value;
 	}
 
@@ -447,7 +446,11 @@  static int emit_mocs_l3cc_table(struct i915_request *rq,
 	if (IS_ERR(cs))
 		return PTR_ERR(cs);
 
-	*cs++ = MI_LOAD_REGISTER_IMM(table->n_entries / 2);
+	/*
+	 * GEN9_LNCFCMOCS is not engine relative, therefore there is no
+	 * need for relative addressing?
+	 */
+	*cs++ = __MI_LOAD_REGISTER_IMM(table->n_entries / 2);
 
 	for (i = 0; i < table->size / 2; i++) {
 		u16 low = get_entry_l3cc(table, 2 * i);
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 8a19eee9c5d4..f2a410c48c7b 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1601,12 +1601,13 @@  static int load_pd_dir(struct i915_request *rq,
 	if (IS_ERR(cs))
 		return PTR_ERR(cs);
 
-	*cs++ = MI_LOAD_REGISTER_IMM(1);
-	*cs++ = i915_mmio_reg_offset(RING_PP_DIR_DCLV(engine->mmio_base));
+	/* Can these not be merged into a single LRI??? */
+	*cs++ = i915_get_lri_cmd(engine, 1);
+	*cs++ = i915_get_lri_reg(engine, RING_PP_DIR_DCLV(engine->mmio_base));
 	*cs++ = PP_DIR_DCLV_2G;
 
-	*cs++ = MI_LOAD_REGISTER_IMM(1);
-	*cs++ = i915_mmio_reg_offset(RING_PP_DIR_BASE(engine->mmio_base));
+	*cs++ = i915_get_lri_cmd(engine, 1);
+	*cs++ = i915_get_lri_reg(engine, RING_PP_DIR_BASE(engine->mmio_base));
 	*cs++ = ppgtt->pd.base.ggtt_offset << 10;
 
 	intel_ring_advance(rq, cs);
@@ -1671,7 +1672,11 @@  static inline int mi_set_context(struct i915_request *rq, u32 flags)
 		if (num_engines) {
 			struct intel_engine_cs *signaller;
 
-			*cs++ = MI_LOAD_REGISTER_IMM(num_engines);
+			/*
+			 * Must use absolute engine address as the register
+			 * write is targeting a different engine.
+			 */
+			*cs++ = __MI_LOAD_REGISTER_IMM(num_engines);
 			for_each_engine(signaller, i915, id) {
 				if (signaller == engine)
 					continue;
@@ -1717,7 +1722,11 @@  static inline int mi_set_context(struct i915_request *rq, u32 flags)
 			struct intel_engine_cs *signaller;
 			i915_reg_t last_reg = {}; /* keep gcc quiet */
 
-			*cs++ = MI_LOAD_REGISTER_IMM(num_engines);
+			/*
+			 * Must use absolute engine address as the register
+			 * write is targeting a different engine.
+			 */
+			*cs++ = __MI_LOAD_REGISTER_IMM(num_engines);
 			for_each_engine(signaller, i915, id) {
 				if (signaller == engine)
 					continue;
@@ -1759,9 +1768,9 @@  static int remap_l3(struct i915_request *rq, int slice)
 	 * here because no other code should access these registers other than
 	 * at initialization time.
 	 */
-	*cs++ = MI_LOAD_REGISTER_IMM(GEN7_L3LOG_SIZE/4);
+	*cs++ = i915_get_lri_cmd(rq->engine, GEN7_L3LOG_SIZE/4);
 	for (i = 0; i < GEN7_L3LOG_SIZE/4; i++) {
-		*cs++ = i915_mmio_reg_offset(GEN7_L3LOG(slice, i));
+		*cs++ = i915_get_lri_reg(rq->engine, GEN7_L3LOG(slice, i));
 		*cs++ = remap_info[i];
 	}
 	*cs++ = MI_NOOP;
@@ -2346,3 +2355,23 @@  int intel_init_vebox_ring_buffer(struct intel_engine_cs *engine)
 
 	return intel_init_ring_buffer(engine);
 }
+
+u32 i915_get_lri_cmd(const struct intel_engine_cs *engine, u32 word_count)
+{
+	u32 word;
+
+	word = __MI_LOAD_REGISTER_IMM(word_count);
+
+	if (i915_engine_has_relative_lri(engine))
+		word |= MI_LRI_ADD_CS_MMIO_START;
+
+	return word;
+}
+
+u32 i915_get_lri_reg(const struct intel_engine_cs *engine, i915_reg_t reg)
+{
+	if (!i915_engine_has_relative_lri(engine))
+		return i915_mmio_reg_offset(reg);
+
+	return i915_mmio_reg_offset(reg) - engine->mmio_base;
+}
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
index e58d6f04177b..8f89cc14b3e0 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.h
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
@@ -581,4 +581,8 @@  intel_engine_get_hangcheck_seqno(struct intel_engine_cs *engine)
 	return intel_read_status_page(engine, I915_GEM_HWS_HANGCHECK);
 }
 
+bool i915_engine_has_relative_lri(const struct intel_engine_cs *engine);
+u32 i915_get_lri_cmd(const struct intel_engine_cs *engine, u32 word_count);
+u32 i915_get_lri_reg(const struct intel_engine_cs *engine, i915_reg_t reg);
+
 #endif /* _INTEL_RINGBUFFER_H_ */
diff --git a/drivers/gpu/drm/i915/intel_workarounds.c b/drivers/gpu/drm/i915/intel_workarounds.c
index a04dbc58ec1c..0b6c81f5e65c 100644
--- a/drivers/gpu/drm/i915/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/intel_workarounds.c
@@ -614,9 +614,9 @@  int intel_engine_emit_ctx_wa(struct i915_request *rq)
 	if (IS_ERR(cs))
 		return PTR_ERR(cs);
 
-	*cs++ = MI_LOAD_REGISTER_IMM(wal->count);
+	*cs++ = i915_get_lri_cmd(rq->engine, wal->count);
 	for (i = 0, wa = wal->list; i < wal->count; i++, wa++) {
-		*cs++ = i915_mmio_reg_offset(wa->reg);
+		*cs++ = i915_get_lri_reg(rq->engine, wa->reg);
 		*cs++ = wa->val;
 	}
 	*cs++ = MI_NOOP;
diff --git a/drivers/gpu/drm/i915/selftests/intel_workarounds.c b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
index 3baed59008d7..34ef4a3d58b9 100644
--- a/drivers/gpu/drm/i915/selftests/intel_workarounds.c
+++ b/drivers/gpu/drm/i915/selftests/intel_workarounds.c
@@ -487,6 +487,7 @@  static int check_dirty_whitelist(struct i915_gem_context *ctx,
 
 	for (i = 0; i < engine->whitelist.count; i++) {
 		u32 reg = i915_mmio_reg_offset(engine->whitelist.list[i].reg);
+		u32 regLRI = i915_get_lri_reg(engine, engine->whitelist.list[i].reg);
 		u64 addr = scratch->node.start;
 		struct i915_request *rq;
 		u32 srm, lrm, rsvd;
@@ -519,8 +520,8 @@  static int check_dirty_whitelist(struct i915_gem_context *ctx,
 		idx = 1;
 		for (v = 0; v < ARRAY_SIZE(values); v++) {
 			/* LRI garbage */
-			*cs++ = MI_LOAD_REGISTER_IMM(1);
-			*cs++ = reg;
+			*cs++ = i915_get_lri_cmd(engine, 1);
+			*cs++ = regLRI;
 			*cs++ = values[v];
 
 			/* SRM result */
@@ -532,8 +533,8 @@  static int check_dirty_whitelist(struct i915_gem_context *ctx,
 		}
 		for (v = 0; v < ARRAY_SIZE(values); v++) {
 			/* LRI garbage */
-			*cs++ = MI_LOAD_REGISTER_IMM(1);
-			*cs++ = reg;
+			*cs++ = i915_get_lri_cmd(engine, 1);
+			*cs++ = regLRI;
 			*cs++ = ~values[v];
 
 			/* SRM result */