vgsp: mode-29 construct-last golden execution lane + fetch-aligned USERD control offset

- New mode 29 (GOLDEN_EXEC_LAST): identical to mode 28 but skips the
  TURING_COMPUTE_A alloc on the client-wired golden channel (every GR object
  construct there blocks RM); stage 3 completes with the golden handle
  swapped and BIND/GPFIFO_SCHEDULE/token are accepted. Param clamp 0..29.
- Shape bits: bit6 TSG parent (alloc accepted, same no-fetch), bit7 host
  USERD control offset 0 (THE FETCH FIX: the server applies the sysmem
  userd_mem base directly and ignores the captured USERD_INDEX_VALUE=3, so
  GP_PUT/GP_GET live at +0x8c/+0x88; m14: GP_GET advanced 1), bit8
  pre-promote compute object (invalid order: RM blocked -110 + NOCAT
  0x52a8b04).
- Failure diagnostics: REAL GR SEM FAILED now dumps both candidate USERD
  control offsets (ctl and alt).

1 files changed, 225 insertions, 32 deletions

diff --git a/kernel/gsp_phys_booter.c b/kernel/gsp_phys_booter.c
index c049c44..989c91f 100644
--- a/kernel/gsp_phys_booter.c
+++ b/kernel/gsp_phys_booter.c
@@ -638,6 +638,18 @@ bool gsp_phys_boot_requested(void)
  */
 #define GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC		28u
 /*
+ * Mode 29: the construct-last golden execution lane. Identical to mode 28
+ * (same wired golden channel + 9-entry promote + execution swap + suppressed
+ * V6 promote) with ONE ordering change: the ladder's TURING_COMPUTE_A (0xc5c0)
+ * object alloc is skipped, because every GR object construct on a
+ * client-wired golden channel deadlocks the server (m3a-m3g: -110, RM task
+ * blocked). The golden replay itself skips its TURING_A via shape bit5, so
+ * after the wired channel alloc + promote no construct touches the golden
+ * channel again; BIND/GPFIFO_SCHEDULE/token and every forwarded publish run
+ * object-less (the SET_OBJECT 0xc5c0 binding is the live experiment).
+ */
+#define GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST	29u
+/*
  * Mode-28 golden execution channel shape bits (gsp_phys_rmcall_golden_exec_shape,
  * default 7). Every combination keeps the captured flags 0x00200320 and the
  * FBMEM instance/RAMFC/mthd slices; the bits only choose the client-visible
@@ -650,6 +662,37 @@ bool gsp_phys_boot_requested(void)
 #define GSP_PHYS_RMCALL_GOLDEN_EXEC_SHAPE_HOBJ_VAS	BIT(4)
 #define GSP_PHYS_RMCALL_GOLDEN_EXEC_SHAPE_SKIP_TURING_A	BIT(5)
 /*
+ * Shape bit6: parent the golden execution channel to the ladder TSG (with
+ * hVASpace=0 per the TSG rule, kernel_channel.c:429-435) instead of the
+ * captured device parenting. The channel that actually fetches on this board
+ * (V6) is TSG-parented (variant skipctx tsg_parent=true) and is scheduled by
+ * TSG_GPFIFO_SCHEDULE; m11's device-parented golden channel accepted BIND +
+ * channel GPFIFO_SCHEDULE but its PBDMA never fetched (GP_PUT=1, GP_GET=0,
+ * no sem release). This bit tests the runlist-membership hypothesis.
+ */
+#define GSP_PHYS_RMCALL_GOLDEN_EXEC_SHAPE_TSG_PARENT	BIT(6)
+/*
+ * Shape bit7: point the HOST USERD control offset at +0x0 (instead of the
+ * captured +0x600) while leaving the channel flags captured. Pure H2 probe:
+ * if the server applies the sysmem userd_mem base directly and ignores the
+ * captured USERD_INDEX_VALUE=3, the hardware control block lives at +0x8c
+ * while m11/m12 wrote +0x68c (GP_PUT invisible to the PBDMA, GP_GET stuck 0).
+ * Clearing the flags index instead was m13: the channel alloc is REJECTED
+ * (rpc_result=0x51), so this bit must not touch the flags. The failure-path
+ * diagnostic dumps both candidate offsets.
+ */
+#define GSP_PHYS_RMCALL_GOLDEN_EXEC_SHAPE_USERD_INDEX0	BIT(7)
+/*
+ * Shape bit8: allocate TURING_COMPUTE_A (0xc5c0) on the wired golden channel
+ * BETWEEN the channel alloc and the 9-entry promote (a construct-before-
+ * promote ordering that the m3 series never tested; every construct after the
+ * promote deadlocked). Needed because m14 proved the PBDMA fetches
+ * (GP_GET advances at host offset 0) but the engine methods need the class
+ * object the object-less mode 29 skipped. The handle is GOLDEN_GR_OBJ
+ * (0xcaf00058, free because shape bit5 skips the replay's TURING_A).
+ */
+#define GSP_PHYS_RMCALL_GOLDEN_EXEC_SHAPE_PRE_PROMOTE_COMPUTE_OBJ	BIT(8)
+/*
  * Existing fwclient mask bit 8: mode-25 gate for the captured VAS
  * COPY_SERVER_RESERVED_PDES control. The captured control copies three
  * server-RM-internal page-table levels the ladder cannot source safely, so
@@ -707,8 +750,20 @@ bool gsp_phys_boot_requested(void)
  * VA_GOLDEN9_PRIV). One VA-only booking entry, like the accepted globals.
  */
 #define GSP_PHYS_RMCALL_FWCLIENT_MASK_PRIV_VA_ONLY	(1u << 15)
+/*
+ * Mode-25 bisection bit 16: the FECS_EVENT sysmem variant. The FBMEM FECS
+ * entry is refused 0x1f on V6 in every PA-bearing form (combined and
+ * PA-only) while the golden channel accepts the identical entry. The mode-24
+ * sysmem shape (attr 0x6, 4 KB, trust the PA) was never tested alone. With
+ * this bit the FBMEM FECS PA/size are released before the small-buffer
+ * prepare, so the FWCLIENT FECS entry is built from the sysmem chunk
+ * (bit 3 = combined sysmem form) and an extra init-only sysmem entry
+ * (PA + size + attr 0x6, bInitialize=1, bNonmapped=1, like the accepted PM)
+ * is sent after the FECS VA-only booking.
+ */
+#define GSP_PHYS_RMCALL_FWCLIENT_MASK_FECS_SYSMEM	(1u << 16)
 #define GSP_PHYS_RMCALL_GR_PROMOTE_MAX \
-	(GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC)
+	(GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST)
 
 /*
  * Work-submit token notifier slot. The default index is
@@ -7555,6 +7610,8 @@ static const char *gsp_phys_rmcall_gr_promote_name(void)
 		return "mode 27: golden9 9-entry promote on the V6 execution channel only (no golden-channel promote)";
 	case GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC:
 		return "mode 28: golden execution lane (golden channel with client GPFIFO/USERD, 9-entry promote on it, execution switched to it)";
+	case GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST:
+		return "mode 29: construct-last golden execution lane (mode 28 minus the TURING_COMPUTE_A object construct on the wired golden channel)";
 	default:
 		return "off (PROMOTE_CTX never sent)";
 	}
@@ -7935,7 +7992,9 @@ static void gsp_phys_rmcall_golden_3d_on_ladder(void __iomem *bar0)
 	 * GR-instance by-product) must not attach a second one to it.
 	 */
 	if (boot_stage.rmcall_gr_promote ==
-			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC)
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+	    boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST)
 		return;
 	ret = gsp_phys_rmcall_alloc_gr_object_class(bar0,
 			GSP_PHYS_RMCALL_CLASS_GR_3D,
@@ -8196,7 +8255,9 @@ static int gsp_phys_rmcall_golden_replay(void __iomem *bar0)
 	     boot_stage.rmcall_gr_promote ==
 			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN9_V6_ONLY ||
 	     boot_stage.rmcall_gr_promote ==
-			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC) &&
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+	     boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) &&
 	    gsp_phys_rmcall_engine_is_gr()) {
 		if (gsp_phys_rmcall_fwclient_mask_value() &
 		    GSP_PHYS_RMCALL_GOLDEN9_MASK_LADDER_VAS) {
@@ -8302,7 +8363,9 @@ static int gsp_phys_rmcall_golden_replay(void __iomem *bar0)
 	     boot_stage.rmcall_gr_promote ==
 			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN9_V6_ONLY ||
 	     boot_stage.rmcall_gr_promote ==
-			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC) &&
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+	     boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) &&
 	    gsp_phys_rmcall_engine_is_gr()) {
 		ch.flags = cpu_to_le32(GSP_PHYS_RMCALL_CHANNEL_FLAG_GOLDEN9);
 		ch.internal_flags = cpu_to_le32(
@@ -8367,7 +8430,9 @@ static int gsp_phys_rmcall_golden_replay(void __iomem *bar0)
 		 * object alloc.
 		 */
 		if (boot_stage.rmcall_gr_promote ==
-				GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC) {
+				GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+		    boot_stage.rmcall_gr_promote ==
+				GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) {
 			u32 exec_shape =
 				gsp_phys_rmcall_golden_exec_shape_value();
 
@@ -8394,13 +8459,20 @@ static int gsp_phys_rmcall_golden_replay(void __iomem *bar0)
 			    GSP_PHYS_RMCALL_GOLDEN_EXEC_SHAPE_HOBJ_VAS)
 				ch.h_object_buffer =
 					cpu_to_le32(boot_stage.rmcall_vas);
+			if (exec_shape &
+			    GSP_PHYS_RMCALL_GOLDEN_EXEC_SHAPE_TSG_PARENT) {
+				ch_parent = boot_stage.rmcall_tsg;
+				ch.h_va_space = cpu_to_le32(0);
+			}
 		}
 		pr_info("vgsp-boot: rm-call: GOLDEN9 channel shape: flags=0x%x (PRIVILEGED|USERD_INDEX_VALUE=3|USERD_INDEX_PAGE_FIXED, no SKIP_SCRUBBER/SKIP_CTXBUFFER_ALLOC) hObjectBuffer=0 gpFifoEntries=0x%x instance/userd/ramfc/mthd=FBMEM memdescs block=0x%llx (capture-matched apertures)\n",
 			GSP_PHYS_RMCALL_CHANNEL_FLAG_GOLDEN9,
 			GSP_PHYS_RMCALL_GOLDEN_GPFIFO_ENTRIES, golden_fb);
 		if (boot_stage.rmcall_gr_promote ==
-				GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC)
-			pr_info("vgsp-boot: rm-call: GOLDEN EXEC channel shape (mode 28): flags=0x%x (captured) shape=0x%x gpFifoOffset=0x%llx gpFifoEntries=%u hObjectBuffer=0x%x userd=%s size=0x%llx hParent=device hVASpace=0x%x; instance/ramfc/mthd stay FBMEM\n",
+				GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+		    boot_stage.rmcall_gr_promote ==
+				GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST)
+			pr_info("vgsp-boot: rm-call: GOLDEN EXEC channel shape (mode 28/29): flags=0x%x (captured) shape=0x%x gpFifoOffset=0x%llx gpFifoEntries=%u hObjectBuffer=0x%x userd=%s size=0x%llx hParent=%s hVASpace=0x%x; instance/ramfc/mthd stay FBMEM\n",
 				GSP_PHYS_RMCALL_CHANNEL_FLAG_GOLDEN9,
 				gsp_phys_rmcall_golden_exec_shape_value(),
 				le64_to_cpu(ch.gp_fifo_offset),
@@ -8410,7 +8482,9 @@ static int gsp_phys_rmcall_golden_replay(void __iomem *bar0)
 				 cpu_to_le32(GSP_PHYS_RMCALL_ADDR_SYSMEM)) ?
 					"sysmem" : "FBMEM",
 				le64_to_cpu(ch.userd_mem.size),
-				boot_stage.rmcall_vas);
+				ch_parent == boot_stage.rmcall_tsg ?
+					"ladder-TSG" : "device",
+				le32_to_cpu(ch.h_va_space));
 	}
 	ret = gsp_phys_rmcall_alloc(bar0, boot_stage.rmcall_client,
 				    ch_parent,
@@ -8432,6 +8506,38 @@ static int gsp_phys_rmcall_golden_replay(void __iomem *bar0)
 	}
 
 	/*
+	 * Shape bit8: allocate the TURING_COMPUTE_A (0xc5c0) object on the
+	 * wired golden channel BEFORE the 9-entry promote. Every construct
+	 * AFTER the promote on a client-wired golden channel deadlocked RM
+	 * (m3a-m3g); the before-promote ordering is untested. The m14 result
+	 * (GP_GET advances at +0x88 -> the PBDMA fetches) shows the remaining
+	 * blocker is engine-method execution, and the engine methods
+	 * (SET_OBJECT/SET_REPORT_SEMAPHORE 0xc5c0) need this class object in
+	 * the channel's context, which mode 29 skipped.
+	 */
+	if ((boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+	     boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) &&
+	    (gsp_phys_rmcall_golden_exec_shape_value() &
+	     GSP_PHYS_RMCALL_GOLDEN_EXEC_SHAPE_PRE_PROMOTE_COMPUTE_OBJ)) {
+		ret = gsp_phys_rmcall_alloc_gr_object_class(bar0,
+				GSP_PHYS_RMCALL_CLASS_COMPUTE,
+				GSP_PHYS_RMCALL_HANDLE_GOLDEN_GR_OBJ,
+				GSP_PHYS_RMCALL_HANDLE_GOLDEN_CHANNEL,
+				"GOLDEN pre-promote TURING_COMPUTE_A", &rpc,
+				&status);
+		if (ret) {
+			pr_err("vgsp-boot: rm-call: GOLDEN pre-promote TURING_COMPUTE_A (0xc5c0) alloc failed (status=0x%x rpc_result=0x%x ret=%d); the golden replay aborts with no retry\n",
+			       status, rpc, ret);
+			return ret;
+		}
+		pr_info("vgsp-boot: rm-call: GOLDEN pre-promote TURING_COMPUTE_A (0xc5c0) allocated on the wired golden channel 0x%x (hObj=0x%x) before the promote\n",
+			GSP_PHYS_RMCALL_HANDLE_GOLDEN_CHANNEL,
+			GSP_PHYS_RMCALL_HANDLE_GOLDEN_GR_OBJ);
+	}
+
+	/*
 	 * Mode 25: the single atomic 9-entry GPU_PROMOTE_CTX on the golden
 	 * channel, in the captured order/forms. It runs after the channel
 	 * alloc and before the 3D object, matching the wire order of the real
@@ -8445,7 +8551,9 @@ static int gsp_phys_rmcall_golden_replay(void __iomem *bar0)
 	     boot_stage.rmcall_gr_promote ==
 			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN9_V6 ||
 	     boot_stage.rmcall_gr_promote ==
-			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC) &&
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+	     boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) &&
 	    gsp_phys_rmcall_engine_is_gr()) {
 		ret = gsp_phys_rmcall_golden9_promote(bar0);
 		if (ret)
@@ -8453,8 +8561,10 @@ static int gsp_phys_rmcall_golden_replay(void __iomem *bar0)
 	}
 
 	/* 6. TURING_A (0xc597) 3D object on the golden channel (kernel_graphics.c:2409-2433). */
-	if (boot_stage.rmcall_gr_promote ==
-			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC &&
+	if ((boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+	     boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) &&
 	    (gsp_phys_rmcall_golden_exec_shape_value() &
 	     GSP_PHYS_RMCALL_GOLDEN_EXEC_SHAPE_SKIP_TURING_A)) {
 		pr_info("vgsp-boot: rm-call: mode 28: GOLDEN TURING_A 3D object skipped (shape bit5); the ladder's TURING_COMPUTE_A on the same channel provides the GR instance state\n");
@@ -9915,7 +10025,12 @@ static int gsp_phys_rmcall_gr_ctx_promote(void __iomem *bar0)
 	int ret;
 
 	if (!boot_stage.rmcall_ctx_prepared ||
-	    !boot_stage.rmcall_channel || !boot_stage.rmcall_gr_object)
+	    !boot_stage.rmcall_channel ||
+	    (!boot_stage.rmcall_gr_object &&
+	     boot_stage.rmcall_gr_promote !=
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC &&
+	     boot_stage.rmcall_gr_promote !=
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST))
 		return -EINVAL;
 	if (mode == GSP_PHYS_RMCALL_GR_PROMOTE_OFF)
 		return -EOPNOTSUPP;
@@ -9927,7 +10042,8 @@ static int gsp_phys_rmcall_gr_ctx_promote(void __iomem *bar0)
 	 */
 	if ((mode == GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN9 ||
 	     mode == GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN9_V6_ONLY ||
-	     mode == GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC) &&
+	     mode == GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+	     mode == GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) &&
 	    (!gsp_phys_rmcall_golden_enabled() || !gsp_phys_gpu_enabled())) {
 		pr_err("vgsp-boot: rm-call: mode %u requires gsp_phys_rmcall_golden=1 and gsp_phys_gpu=1 (the golden replay did not run); no PROMOTE_CTX is sent and the ladder aborts with no retry\n",
 		       mode);
@@ -9938,8 +10054,9 @@ static int gsp_phys_rmcall_gr_ctx_promote(void __iomem *bar0)
 	 * channel inside the golden replay (it owns the committed context and
 	 * the forwarded launches); nothing is sent on the V6 channel at all.
 	 */
-	if (mode == GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC) {
-		pr_info("vgsp-boot: rm-call: mode-28 golden execution lane: no PROMOTE_CTX on V6 (the golden channel 0x%x carries the committed context); continuing to stage 4 on the golden channel\n",
+	if (mode == GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+	    mode == GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) {
+		pr_info("vgsp-boot: rm-call: mode-28/29 golden execution lane: no PROMOTE_CTX on V6 (the golden channel 0x%x carries the committed context); continuing to stage 4 on the golden channel\n",
 			GSP_PHYS_RMCALL_HANDLE_GOLDEN_CHANNEL);
 		boot_stage.rmcall_gr_promote_step = 1;
 		return 0;
@@ -10693,6 +10810,22 @@ static int gsp_phys_rmcall_gr_ctx_promote(void __iomem *bar0)
 		}
 		if (gsp_phys_rmcall_gr_pm_prepare(bar0))
 			pr_warn("vgsp-boot: rm-call: PROMOTE_CTX fwclient: PM prepare failed; omitting the PM entry and continuing (mode 24 treats PM as best-effort; the reference set pre-allocates it for an externally-owned VAS)\n");
+		/*
+		 * Bit 16: release the FBMEM FECS booking so the small-buffer
+		 * prepare allocates the sysmem 4 KB chunk and the FECS entries
+		 * are built in the mode-24 sysmem shape (attr 0x6). The FBMEM
+		 * chunk/PA itself stays allocated server-side and the PDB
+		 * FECS VA mapping is untouched; only the promote entry source
+		 * changes.
+		 */
+		if ((mask & GSP_PHYS_RMCALL_FWCLIENT_MASK_FECS_SYSMEM) &&
+		    boot_stage.rmcall_fecs_pa && boot_stage.rmcall_fecs_size) {
+			pr_info("vgsp-boot: rm-call: PROMOTE_CTX fwclient FECS sysmem variant: releasing the FBMEM FECS pa=0x%llx size=0x%x to force the sysmem small buffer\n",
+				boot_stage.rmcall_fecs_pa,
+				boot_stage.rmcall_fecs_size);
+			boot_stage.rmcall_fecs_pa = 0;
+			boot_stage.rmcall_fecs_size = 0;
+		}
 		gsp_phys_rmcall_gr_fwclient_small_prepare();
 
 		/*
@@ -11106,6 +11239,35 @@ static int gsp_phys_rmcall_gr_ctx_promote(void __iomem *bar0)
 				GSP_PHYS_RMCALL_VA_GOLDEN9_PRIV, status,
 				rpc_result, boot_stage.rmcall_channel);
 		}
+
+		/*
+		 * Bit 16: the FECS init-only sysmem entry (PA + size + sysmem
+		 * attr 0x6, bInitialize=1, bNonmapped=1) - the form the accepted
+		 * PM entry uses, with the mode-24 sysmem buffer the bit released
+		 * above. Sent after the FECS VA-only booking so the pair is
+		 * complete either way.
+		 */
+		if ((mask & GSP_PHYS_RMCALL_FWCLIENT_MASK_FECS_SYSMEM) &&
+		    boot_stage.rmcall_fecs_pa) {
+			gsp_phys_rmcall_promote_entry_fill(p, 0, 9,
+				boot_stage.rmcall_fecs_pa, 0, 0x1000u,
+				GSP_PHYS_RMCALL_GR_CTX_PHYS_ATTR, 1, 1);
+			p->entry_count = cpu_to_le32(1);
+			rpc_result = 0;
+			status = 0;
+			ret = gsp_phys_rmcall_control(bar0,
+					boot_stage.rmcall_subdevice,
+					GSP_PHYS_RMCALL_CTRL_GPU_PROMOTE_CTX,
+					p, sizeof(*p), 24, NULL, 0,
+					&rpc_result, &status,
+					"GPU_PROMOTE_CTX (FECS sysmem init-only)");
+			pr_info("vgsp-boot: rm-call: PROMOTE_CTX FECS sysmem init-only: bufferId=9 pa=0x%llx size=0x1000 physAttr=0x%x status=0x%x rpc_result=0x%x (hObject=0x%x)\n",
+				boot_stage.rmcall_fecs_pa,
+				GSP_PHYS_RMCALL_GR_CTX_PHYS_ATTR, status,
+				rpc_result, boot_stage.rmcall_channel);
+		} else if (mask & GSP_PHYS_RMCALL_FWCLIENT_MASK_FECS_SYSMEM) {
+			pr_warn("vgsp-boot: rm-call: PROMOTE_CTX FECS sysmem init-only skipped: no sysmem FECS buffer prepared\n");
+		}
 	} else {
 		pr_err("vgsp-boot: rm-call: unknown gr_promote_param=%u reached the promote step; no PROMOTE_CTX is sent and the ladder aborts with no retry\n",
 		       mode);
@@ -11715,7 +11877,9 @@ static int gsp_phys_rmcall_stage3(void __iomem *bar0)
 			if ((boot_stage.rmcall_gr_promote ==
 					GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN9 ||
 			     boot_stage.rmcall_gr_promote ==
-					GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC) &&
+					GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+			     boot_stage.rmcall_gr_promote ==
+					GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) &&
 			    gsp_phys_rmcall_engine_is_gr()) {
 				pr_err("vgsp-boot: rm-call: stage 3 aborted: mode-%u golden replay failed (%d); the golden construct is atomic and is not retried\n",
 				       boot_stage.rmcall_gr_promote, ret);
@@ -11771,12 +11935,17 @@ static int gsp_phys_rmcall_stage3(void __iomem *bar0)
 	 * early in gsp_phys_rmcall_gr_ctx_promote).
 	 */
 	if (gsp_phys_rmcall_engine_is_gr() &&
-	    boot_stage.rmcall_gr_promote ==
-			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC) {
-		pr_info("vgsp-boot: rm-call: mode 28: execution channel switched from V6 0x%x to golden execution channel 0x%x (client ring gpFifoVa=0x%llx userd=sysmem, device-parented); the V6 channel stays unscheduled\n",
+	    (boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+	     boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST)) {
+		pr_info("vgsp-boot: rm-call: mode 28/29: execution channel switched from V6 0x%x to golden execution channel 0x%x (client ring gpFifoVa=0x%llx userd=%s, device-parented); the V6 channel stays unscheduled\n",
 			boot_stage.rmcall_channel,
 			GSP_PHYS_RMCALL_HANDLE_GOLDEN_CHANNEL,
-			GSP_PHYS_RMCALL_VA_GPFIFO);
+			GSP_PHYS_RMCALL_VA_GPFIFO,
+			boot_stage.rmcall_gr_promote ==
+				GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST ?
+				"sysmem" : "captured");
 		boot_stage.rmcall_channel =
 			GSP_PHYS_RMCALL_HANDLE_GOLDEN_CHANNEL;
 		boot_stage.rmcall_channel_server_mem = false;
@@ -11793,11 +11962,17 @@ static int gsp_phys_rmcall_stage3(void __iomem *bar0)
 	 */
 	if (gsp_phys_rmcall_engine_is_gr()) {
 		gsp_phys_rmcall_golden_3d_on_ladder(bar0);
-		ret = gsp_phys_rmcall_alloc_gr_object(bar0);
-		if (ret) {
-			pr_err("vgsp-boot: rm-call: stage 3 aborted: TURING_COMPUTE_A (0xc5c0) engine object alloc failed (%d); the GR ladder has no engine object to bind and is not retried\n",
-			       ret);
-			return ret;
+		if (boot_stage.rmcall_gr_promote ==
+		    GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) {
+			pr_info("vgsp-boot: rm-call: mode 29: skipping the TURING_COMPUTE_A (0xc5c0) object alloc: every GR object construct on the client-wired golden channel deadlocked the server (m3a-m3g); the golden execution lane runs object-less (the SET_OBJECT 0xc5c0 binding is the live experiment)\n");
+			boot_stage.rmcall_gr_object = 0;
+		} else {
+			ret = gsp_phys_rmcall_alloc_gr_object(bar0);
+			if (ret) {
+				pr_err("vgsp-boot: rm-call: stage 3 aborted: TURING_COMPUTE_A (0xc5c0) engine object alloc failed (%d); the GR ladder has no engine object to bind and is not retried\n",
+				       ret);
+				return ret;
+			}
 		}
 		/*
 		 * gr_promote_param=0 stops here: the whole pre-promote half
@@ -12016,10 +12191,18 @@ struct gsp_phys_rmcall_ce_submit {
  */
 static u32 gsp_phys_rmcall_userd_ctl_off(void)
 {
-	if (boot_stage.rmcall_gr_promote ==
-			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC &&
-	    gsp_phys_rmcall_engine_is_gr())
+	if ((boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC ||
+	     boot_stage.rmcall_gr_promote ==
+			GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST) &&
+	    gsp_phys_rmcall_engine_is_gr()) {
+		if (boot_stage.rmcall_gr_promote ==
+				GSP_PHYS_RMCALL_GR_PROMOTE_GOLDEN_EXEC_LAST &&
+		    (gsp_phys_rmcall_golden_exec_shape_value() &
+		     GSP_PHYS_RMCALL_GOLDEN_EXEC_SHAPE_USERD_INDEX0))
+			return 0;
 		return GSP_PHYS_RMCALL_USERD_CTL_OFF_CAPTURED;
+	}
 	return 0;
 }
 
@@ -12267,14 +12450,24 @@ static int gsp_phys_rmcall_gr_sem_push_locked(void __iomem *bar0)
 		if (poll == GSP_PHYS_RMCALL_SEM_PAYLOAD)
 			break;
 		if (time_after_eq(jiffies, deadline)) {
-			gpget = get_unaligned_le32((u8 *)userd + gsp_phys_rmcall_userd_ctl_off() +
+			u32 off = gsp_phys_rmcall_userd_ctl_off();
+			u32 alt = off ? 0u :
+				GSP_PHYS_RMCALL_USERD_CTL_OFF_CAPTURED;
+
+			gpget = get_unaligned_le32((u8 *)userd + off +
 						   GSP_PHYS_RMCALL_USERD_GPGET_OFF);
-			gpput = get_unaligned_le32((u8 *)userd + gsp_phys_rmcall_userd_ctl_off() +
+			gpput = get_unaligned_le32((u8 *)userd + off +
 						   GSP_PHYS_RMCALL_USERD_GPPUT_OFF);
-			pr_err("vgsp-boot: rm-call: REAL GR SEM FAILED: no release within %u ms (sem=0x%08x want=0x%08x GPGet=%u GPPut=%u engine=%s); the channel did not execute the GR block\n",
+			pr_err("vgsp-boot: rm-call: REAL GR SEM FAILED: no release within %u ms (sem=0x%08x want=0x%08x GPGet=%u GPPut=%u engine=%s); the channel did not execute the GR block (ctl=0x%x GPGet=%u GPPut=%u | alt ctl=0x%x GPGet=%u GPPut=%u)\n",
 			       GSP_PHYS_RMCALL_TIMEOUT_MS, poll,
 			       GSP_PHYS_RMCALL_SEM_PAYLOAD, gpget, gpput,
-			       gsp_phys_rmcall_engine_name());
+			       gsp_phys_rmcall_engine_name(),
+			       off, gpget, gpput,
+			       alt,
+			       get_unaligned_le32((u8 *)userd + alt +
+						  GSP_PHYS_RMCALL_USERD_GPGET_OFF),
+			       get_unaligned_le32((u8 *)userd + alt +
+						  GSP_PHYS_RMCALL_USERD_GPPUT_OFF));
 			gsp_phys_status_drain(NULL);
 			return -ETIMEDOUT;
 		}