soc: apple: report the T6031 GPU to the PMP

drivers/gpu/drm/asahi/Kconfig

@@ -67,6 +67,7 @@ config DRM_ASAHI_G15
 	depends on DRM_ASAHI
 	depends on DRM_APPLE=y || (DRM_APPLE=m && DRM_ASAHI=m)
 	select APPLE_T6030_GPU_PMP_LINK
+	select APPLE_T6031_GPU_PMP_REPORT
 	select CRYPTO_LIB_SHA256
 	select DRM_ASAHI_UAT_ADOPTION
 	default n

drivers/gpu/drm/asahi/g15/boot.rs

@@ -1,3 +1,3 @@
 // SPDX-License-Identifier: GPL-2.0-only OR MIT
 
 //! Admission and firmware start to READY.
@@ -75,6 +75,7 @@
         pub(crate) fn asahi_g15_display_prepare(dev: *mut core::ffi::c_void) -> core::ffi::c_int;
         pub(crate) fn asahi_g15_pmp_get(dev: *mut core::ffi::c_void) -> core::ffi::c_int;
         pub(crate) fn asahi_g15_pmp_ready() -> core::ffi::c_int;
+        pub(crate) fn asahi_g15_pmp_report_t6031(enable: bool) -> core::ffi::c_int;
         pub(crate) fn asahi_g15_pmp_put(dev: *mut core::ffi::c_void);
         fn asahi_g15_reserved_uat(index: u32, start: u64, size: u64) -> bool;
     }

drivers/gpu/drm/asahi/g15/glue.c

@@ -19,6 +19,7 @@
 #include <linux/pfn.h>
 #include <linux/pm_runtime.h>
 #include <linux/soc/apple/pmp.h>
+#include <linux/soc/apple/pmp-report.h>
 #include <linux/soc/apple/display.h>
 
 void asahi_g15_sha256(const u8 *data, size_t len, u8 *out);
@@ -37,6 +38,7 @@ int asahi_g15_pmp_prepare(struct device *dev);
 int asahi_g15_display_prepare(struct device *dev);
 int asahi_g15_pmp_get(struct device *dev);
 int asahi_g15_pmp_ready(void);
+int asahi_g15_pmp_report_t6031(bool enable);
 void asahi_g15_pmp_put(struct device *dev);
 bool asahi_g15_reserved_uat(u32 index, u64 start, u64 size);
 
@@ -184,6 +186,12 @@ int asahi_g15_pmp_ready(void)
 	return apple_pmp_t6030_gpu_ready();
 }
 
+/* T6031: the AGX request of the PMP report, after the firmware is running. */
+int asahi_g15_pmp_report_t6031(bool enable)
+{
+	return apple_pmp_report_t6031_gfx(enable);
+}
+
 /*
  * Give back the vote of asahi_g15_pmp_get() after a start that failed before
  * the firmware was touched. The full M3 stack's J514S bridge has no release:

drivers/gpu/drm/asahi/g15/mod.rs

@@ -1,3 +1,3 @@
 // SPDX-License-Identifier: GPL-2.0-only OR MIT
 
 //! G15 GPU support (T6030, M3 Pro: J514S, J516S; firmware RTKit 2419, the macOS 14.7-14.8 stub).
@@ -566,6 +566,21 @@
             } = KBox::into_inner(firmware);
             return Err(orphan(session, objects, channels, init, events, e));
         }
+        if cfg.platform == hw::Platform::DeviceTree {
+            // T6031: nothing else sets the PMP's AGX request, and without it memory stays at its
+            // idle floor. Set it after setup, as T6030 does; a failure keeps the GPU as before.
+            // SAFETY: The session is retained until reboot, and the request with it.
+            let ret = unsafe { boot::glue::asahi_g15_pmp_report_t6031(true) };
+            if ret == 0 {
+                dev_info!(dev.as_ref(), "G15: PMP AGX request set (memory bandwidth scaling)\n");
+            } else if ret != ENODEV.to_errno() {
+                dev_warn!(
+                    dev.as_ref(),
+                    "G15: PMP AGX request failed ({}); memory stays at its idle floor\n",
+                    ret
+                );
+            }
+        }
         Ok(firmware)
     }
 }

drivers/pmdomain/apple/pmp-report.c

@@ -1348,6 +1348,58 @@ int apple_pmp_report_set_t6030_gfx(struct device *supplier, bool enable)
 }
 EXPORT_SYMBOL_GPL(apple_pmp_report_set_t6030_gfx);
 
+/*
+ * T6031 (M3 Max): the GPU is powered by its PMGR domain alone, with no RTKit
+ * vote, and nothing sets its PTD request, so PMP ignores the GPU's bandwidth
+ * demand and memory stays at its idle floor. AGX is the acknowledged
+ * soc-device ID 14 (record 13) of the J516C table. As on T6030, a request
+ * made before the firmware runs is acknowledged without enabling bandwidth
+ * scaling: enabling clears and sets it again. On a failed enable the request
+ * is cleared, which is how the GPU ran before.
+ */
+int apple_pmp_report_t6031_gfx(bool enable)
+{
+	struct apple_pmp_report *rep, *found = NULL;
+	struct device_node *pmp = NULL;
+	const u8 *table = NULL;
+	int len = 0, ret = -ENODEV;
+
+	if (!IS_ENABLED(CONFIG_APPLE_T6031_GPU_PMP_REPORT) ||
+	    !of_machine_is_compatible("apple,t6031"))
+		return -ENODEV;
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(rep, &apple_pmp_reports, list) {
+		if (rep->offsets != &apple_pmp_offsets_t6031)
+			continue;
+		if (found)
+			goto out;
+		found = rep;
+	}
+	if (!found)
+		goto out;
+	pmp = of_parse_phandle(found->dev->of_node, "apple,pmp", 0);
+	if (pmp && of_device_is_compatible(pmp, "apple,t6031-pmp-v2"))
+		table = of_get_property(pmp, "apple,tunable-soc-device", &len);
+	if (!apple_pmp_devices_valid(table, len > 0 ? len : 0, BIT_ULL(13), BIT_ULL(13), true) ||
+	    memcmp(table + 13 * PMP_SOC_DEVICE_SIZE + 116, "AGX\0\0\0\0\0", 8)) {
+		ret = -EINVAL;
+	} else if (readq(found->base + found->offsets->status) != PMP_REPORT_READY) {
+		ret = -EAGAIN;
+	} else {
+		ret = apple_pmp_report_set_state(found, 13, false, false);
+		if (!ret && enable)
+			ret = apple_pmp_report_set_state(found, 13, true, false);
+		if (ret && enable)
+			apple_pmp_report_set_state(found, 13, false, false);
+	}
+	of_node_put(pmp);
+out:
+	rcu_read_unlock();
+	return ret;
+}
+EXPORT_SYMBOL_GPL(apple_pmp_report_t6031_gfx);
+
 static int apple_pmp_report_entry_set_state(struct generic_pm_domain *genpd, bool enable)
 {
 	struct apple_pmp_report_entry *ent = genpd_to_apple_pmp_report_entry(genpd);

drivers/soc/apple/Kconfig

@@ -257,6 +257,16 @@ config APPLE_T6030_GPU_PMP_LINK
 	  GPU power commands wait for that supplier's acknowledged display
 	  request through the existing PMP report startup and removal rules.
 
+config APPLE_T6031_GPU_PMP_REPORT
+	bool
+	depends on APPLE_PMP_REPORT
+	default n
+	help
+	  Set the AGX request of the T6031 (M3 Max) PMP report once the G15
+	  firmware runs. The T6031 GPU is powered by its PMGR domain alone, so
+	  nothing else sets that request, and without it the PMP ignores the
+	  GPU's bandwidth demand: memory stays at its idle floor.
+
 config APPLE_DISPLAY_GATE_KUNIT_TEST
 	bool "KUnit tests for the Apple display gate" if !KUNIT_ALL_TESTS
 	depends on KUNIT=y && APPLE_T6030_DISPLAY_GATE

include/linux/soc/apple/pmp-report.h

@@ -18,6 +18,8 @@ int apple_pmp_report_wait_supplier_ready(struct device *supplier, unsigned int t
 /* Caller holds the PMP owner's vote lock and keeps the supplier bound. */
 int apple_pmp_report_check_t6030_gfx(struct device *supplier);
 int apple_pmp_report_set_t6030_gfx(struct device *supplier, bool enable);
+/* After the T6031 G15 firmware is running; the request stays until reboot. */
+int apple_pmp_report_t6031_gfx(bool enable);
 int apple_pmp_report_wait_ready(struct device_node *entry, unsigned long timeout);
 int apple_pmp_report_fast_die_effort(const struct device_node *np,
 				     unsigned int lane, u8 *effort);
@@ -38,6 +40,11 @@ static inline int apple_pmp_report_set_t6030_gfx(struct device *supplier, bool e
 	return -ENODEV;
 }
 
+static inline int apple_pmp_report_t6031_gfx(bool enable)
+{
+	return -ENODEV;
+}
+
 static inline int apple_pmp_report_wait_ready(struct device_node *entry,
 					      unsigned long timeout)
 {