drm/apple: traced firmware 27.3 IOMFB method IDs

drivers/gpu/drm/apple/dcp-internal.h

@@ -457,6 +457,8 @@ struct apple_dcp {
 	enum dcp_firmware_version fw_compat;
 	/* Bumped by every iomfb poweron; see afk_compact_slot(). */
 	u32 afk_power_gen;
+	/* Firmware 27.x: the method IDs of this build (iomfb_v27_methods()). */
+	const struct dcp_method_entry *v27_methods;
 	bool external;
 	/* A desktop 26.x external processor (apple,t6041-dcpext) */
 	bool desktop_external;

drivers/gpu/drm/apple/dcp.c

@@ -5044,6 +5044,8 @@ static enum dcp_firmware_version dcp_check_firmware_version(struct device *dev)
 	const struct dcp_v14_board *v14_board;
 	char compat_str[DCP_FW_VERSION_STR_LEN];
 	char fw_str[DCP_FW_VERSION_STR_LEN];
+	unsigned int num_missing;
+	const char *missing;
 	int ret;
 
 	/*
@@ -5060,8 +5062,18 @@ static enum dcp_firmware_version dcp_check_firmware_version(struct device *dev)
 
 	if (hw->firmware_compat == DCP_FIRMWARE_V_27_0) {
 		ret = dcp_read_fw_version(dev, "apple,firmware-compat", compat_str);
-		if (ret < 0 || strcmp(compat_str, "27.0.0"))
+		if (ret < 0 || !iomfb_v27_methods(compat_str)) {
+			dev_err(dev, "DCP firmware-compat %s has no 27.x method table\n",
+				ret < 0 ? "missing" : compat_str);
 			return DCP_FIRMWARE_UNKNOWN;
+		}
+		missing = iomfb_v27_missing_method(iomfb_v27_methods(compat_str),
+						   &num_missing);
+		if (missing) {
+			dev_err(dev, "DCP firmware-compat %s not started: no ID known for %u methods (first: %s)\n",
+				compat_str, num_missing, missing);
+			return DCP_FIRMWARE_UNKNOWN;
+		}
 		return DCP_FIRMWARE_V_27_0;
 	}
 
@@ -6174,6 +6186,13 @@ static int dcp_platform_probe_pipe(struct platform_device *pdev)
 				return -ENOMEM;
 		}
 	}
+	if (fw_compat == DCP_FIRMWARE_V_27_0) {
+		char compat_str[DCP_FW_VERSION_STR_LEN];
+
+		/* Checked by dcp_check_firmware_version(). */
+		dcp_read_fw_version(dev, "apple,firmware-compat", compat_str);
+		dcp->v27_methods = iomfb_v27_methods(compat_str);
+	}
 	if (fw_compat == DCP_FIRMWARE_V_26_6_DESKTOP) {
 		dcp->desktop = devm_kzalloc(dev, sizeof(*dcp->desktop), GFP_KERNEL);
 		if (!dcp->desktop)

drivers/gpu/drm/apple/iomfb-peer-runtime-v27.inc

@@ -83,12 +83,12 @@ static void dcp_peer_started_on_owner(struct apple_dcp *owner, void *data, void
 	dcp_peer_swap_armed_v27(owner, id);
 	trace_iomfb_swap_submit(owner, id);
 	trace_iomfb_swap_submit(peer, id);
-	dcp_push(owner, false, &dcp_methods[dcpep_swap_submit], sizeof(owner->present_v27),
+	dcp_push(owner, false, &owner->v27_methods[dcpep_swap_submit], sizeof(owner->present_v27),
 		 sizeof(struct dcp_swap_submit_resp_v27), &owner->present_v27,
 		 dcp_peer_submitted, owner);
 	if (READ_ONCE(owner->crashed))
 		return;
-	dcp_push(peer, false, &dcp_methods[dcpep_swap_submit], sizeof(owner->peer_present_v27),
+	dcp_push(peer, false, &peer->v27_methods[dcpep_swap_submit], sizeof(owner->peer_present_v27),
 		 sizeof(struct dcp_swap_submit_resp_v27), &owner->peer_present_v27,
 		 dcp_peer_submitted, owner);
 	if (READ_ONCE(peer->crashed))

drivers/gpu/drm/apple/iomfb.h

@@ -212,6 +212,12 @@ struct dcp_method_entry {
 	char tag_h17g[4];
 };
 
+/* The IOMFB method table of a firmware 27.x build, by its compat string; NULL if unknown. */
+const struct dcp_method_entry *iomfb_v27_methods(const char *compat);
+/* The first method of a firmware 27.x table that has no ID, NULL if none. */
+const char *iomfb_v27_missing_method(const struct dcp_method_entry *methods,
+				     unsigned int *count);
+
 #define IOMFB_MAX_CB (1000)
 
 bool iomfb_validate_callback_h17p(int tag, u32 in_len, u32 out_len);

drivers/gpu/drm/apple/iomfb_template.c

@@ -1706,6 +1706,11 @@ static void boot_5(struct apple_dcp *dcp, void *out, void *cookie)
 {
 #if DCP_FW_H17(DCP_FW_VER)
 	/* H17P expects A380 right before set_display_refresh_properties */
+	if (!dcp_methods[dcpep_dfb_ready_query].tag[0]) {
+		/* No tag is known for this firmware build: do not send one. */
+		boot_5b(dcp, out, cookie);
+		return;
+	}
 	dcp_dfb_ready_query(dcp, false, boot_5b, NULL);
 #else
 	boot_5b(dcp, out, cookie);

drivers/gpu/drm/apple/iomfb_v27.c

@@ -69,7 +69,8 @@ static_assert(offsetof(struct dcp_swap_v27, brightness_update) == 0x354);
 static_assert(offsetof(struct dcp_swap_v27, brightness_nits) == 0x35e);
 static_assert(sizeof(struct dcp_swap_v27) == 0x6e0);
 
-static const struct dcp_method_entry dcp_methods[dcpep_num_methods] = {
+/* Firmware 27.0, the build Aurora's t6050-gpu table was written for. */
+static const struct dcp_method_entry dcp_methods_27_0[dcpep_num_methods] = {
 	IOMFB_METHOD("A000", dcpep_late_init_signal),
 	IOMFB_METHOD("A027", dcpep_setup_video_limits),
 	IOMFB_METHOD("A136", iomfbep_a131_pmu_service_matched),
@@ -113,6 +114,132 @@ static const struct dcp_method_entry dcp_methods[dcpep_num_methods] = {
 	IOMFB_METHOD("A483", dcpep_register_dfb_surface),
 };
 
+/*
+ * Firmware 27.2 renumbered the AP methods: UnifiedPipeline2 grew into
+ * A400/A401, so IOMobileFramebufferAP moved up by 50 (start_signal A451,
+ * get_color_remap_mode A477), and set_create_DFB and vi_set_temperature_hint
+ * up by one. The UPPipe A0xx and A1xx IDs are unchanged. The firmware rejects
+ * an unknown tag with a panic ("link_rpc_lookup callback not found"), so
+ * dfb_ready_query, whose 27.2 tag has not been seen in a call, has no entry
+ * here and is not sent to this build (boot_5()).
+ */
+static const struct dcp_method_entry dcp_methods_27_2[dcpep_num_methods] = {
+	IOMFB_METHOD("A000", dcpep_late_init_signal),
+	IOMFB_METHOD("A027", dcpep_setup_video_limits),
+	IOMFB_METHOD("A136", iomfbep_a131_pmu_service_matched),
+	IOMFB_METHOD("A137", iomfbep_a132_backlight_service_matched),
+	IOMFB_METHOD("A390", dcpep_set_create_dfb),
+	IOMFB_METHOD("A391", iomfbep_a358_vi_set_temperature_hint),
+	IOMFB_METHOD("A451", dcpep_start_signal),
+	IOMFB_METHOD("A456", dcpep_swap_start),
+	IOMFB_METHOD("A458", dcpep_swap_submit),
+	IOMFB_METHOD("A461", dcpep_set_display_device),
+	IOMFB_METHOD("A462", dcpep_is_main_display),
+	IOMFB_METHOD("A463", dcpep_set_digital_out_mode),
+	IOMFB_METHOD("A473", iomfbep_set_matrix),
+	IOMFB_METHOD("A477", iomfbep_get_color_remap_mode),
+	IOMFB_METHOD("A500", dcpep_set_parameter_dcp),
+	IOMFB_METHOD("A504", dcpep_create_default_fb),
+	IOMFB_METHOD("A037", dcpep_get_dfb_compression_info),
+	IOMFB_METHOD("A036", dcpep_get_dfb_info),
+	IOMFB_METHOD("A103", dcpep_get_dfb_layout),
+	IOMFB_METHOD("A503", dcpep_get_dfb_state),
+	IOMFB_METHOD("A104", dcpep_set_dfb_dimensions),
+	IOMFB_METHOD("A105", dcpep_commit_dfb_info),
+	IOMFB_METHOD("A035", dcpep_dfb_query),
+	IOMFB_METHOD("A353", dcpep_pipe_query_353),
+	IOMFB_METHOD("A352", dcpep_pipe_set_352),
+	IOMFB_METHOD("A465", dcpep_pipe_cfg_415),
+	IOMFB_METHOD("A033", dcpep_pipe_cfg_031),
+	IOMFB_METHOD("A464", dcpep_pipe_cfg_414),
+	IOMFB_METHOD("A539", dcpep_pipe_query_478),
+	IOMFB_METHOD("A535", dcpep_pipe_query_474),
+	IOMFB_METHOD("A537", dcpep_pipe_set_476),
+	IOMFB_METHOD("A478", iomfbep_set_brightness_correction),
+	IOMFB_METHOD("A508", dcpep_enable_disable_video_power_savings),
+	IOMFB_METHOD("A516", dcpep_first_client_open),
+	IOMFB_METHOD("A517", iomfbep_last_client_close),
+	IOMFB_METHOD("A525", dcpep_set_display_refresh_properties),
+	IOMFB_METHOD("A528", dcpep_flush_supports_power),
+	IOMFB_METHOD("A529", iomfbep_abort_swaps_dcp),
+	IOMFB_METHOD("A534", dcpep_set_power_state),
+	IOMFB_METHOD("A533", dcpep_register_dfb_surface),
+};
+
+/*
+ * Firmware 27.3: only the methods seen, with the request and reply sizes this
+ * driver uses, in a trace of the calls the macOS 27.3 display driver makes to
+ * the DCP of a J716s while it starts. Three are one above their 27.2 IDs
+ * (set_display_refresh_properties A526, flush_supports_power A529,
+ * register_dfb_surface A534) and create_default_fb is still A504, so 27.3 has
+ * one more method somewhere between those. That trace has no display client,
+ * so it has no mode set, swap or power state call, and the methods it does not
+ * show have no entry here. Until a trace shows them the table is incomplete
+ * and the driver does not start this firmware (iomfb_v27_missing_method()).
+ */
+static const struct dcp_method_entry dcp_methods_27_3[dcpep_num_methods] = {
+	IOMFB_METHOD("A000", dcpep_late_init_signal),
+	IOMFB_METHOD("A027", dcpep_setup_video_limits),
+	IOMFB_METHOD("A136", iomfbep_a131_pmu_service_matched),
+	IOMFB_METHOD("A137", iomfbep_a132_backlight_service_matched),
+	IOMFB_METHOD("A390", dcpep_set_create_dfb),
+	IOMFB_METHOD("A391", iomfbep_a358_vi_set_temperature_hint),
+	IOMFB_METHOD("A451", dcpep_start_signal),
+	IOMFB_METHOD("A504", dcpep_create_default_fb),
+	IOMFB_METHOD("A037", dcpep_get_dfb_compression_info),
+	IOMFB_METHOD("A036", dcpep_get_dfb_info),
+	IOMFB_METHOD("A103", dcpep_get_dfb_layout),
+	IOMFB_METHOD("A503", dcpep_get_dfb_state),
+	IOMFB_METHOD("A104", dcpep_set_dfb_dimensions),
+	IOMFB_METHOD("A105", dcpep_commit_dfb_info),
+	IOMFB_METHOD("A035", dcpep_dfb_query),
+	IOMFB_METHOD("A385", dcpep_dfb_ready_query),
+	IOMFB_METHOD("A353", dcpep_pipe_query_353),
+	IOMFB_METHOD("A526", dcpep_set_display_refresh_properties),
+	IOMFB_METHOD("A529", dcpep_flush_supports_power),
+	IOMFB_METHOD("A534", dcpep_register_dfb_surface),
+};
+
+const struct dcp_method_entry *iomfb_v27_methods(const char *compat)
+{
+	if (!strcmp(compat, "27.0.0"))
+		return dcp_methods_27_0;
+	if (!strcmp(compat, "27.2.0"))
+		return dcp_methods_27_2;
+	if (!strcmp(compat, "27.3.0"))
+		return dcp_methods_27_3;
+	return NULL;
+}
+
+/*
+ * The driver sends every method of the 27.0 table. dfb_ready_query is the one
+ * it leaves out for a build whose table has no ID for it (boot_5()). Return
+ * the name of the first other method @methods has no ID for, with their number
+ * in @count, or NULL if the table is complete. A method without an ID would go
+ * out with an empty tag, which the firmware answers with a panic, so a build
+ * with an incomplete table must not be started.
+ */
+const char *iomfb_v27_missing_method(const struct dcp_method_entry *methods,
+				     unsigned int *count)
+{
+	const char *first = NULL;
+	unsigned int i;
+
+	*count = 0;
+	for (i = 0; i < dcpep_num_methods; i++) {
+		if (!dcp_methods_27_0[i].tag[0] || methods[i].tag[0] ||
+		    i == dcpep_dfb_ready_query)
+			continue;
+		if (!first)
+			first = dcp_methods_27_0[i].name;
+		(*count)++;
+	}
+	return first;
+}
+
+/* The template's calls resolve through the table probe chose for this build. */
+#define dcp_methods (dcp->v27_methods)
+
 #define iomfb_modeset_h17p iomfb_modeset_v27
 #define iomfb_flush_h17p iomfb_flush_v27
 #define iomfb_poweron_h17p iomfb_poweron_v27