soc: apple: retain the live J613 MTP through s2idle

drivers/iommu/apple-dart.c

@@ -36,6 +36,8 @@
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/pm_wakeup.h>
+#include <linux/suspend.h>
 #include <linux/slab.h>
 #include <linux/soc/apple/tunable.h>
 #include <linux/swab.h>
@@ -286,6 +288,9 @@ struct apple_dart {
 	u32 pgsize;
 	u32 num_streams;
 	u32 supports_bypass : 1;
+	/* J613 MTP keeps issuing DMA in the boot loader identity domain. */
+	bool live_mtp;
+	bool live_mtp_sleep;
 	u32 four_level : 1;
 	u32 locked : 1;
 	u32 tunneled : 1;
@@ -2032,6 +2037,10 @@ static int apple_dart_attach_dev_paging(struct iommu_domain *domain,
 	struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 	struct apple_dart_domain *dart_domain = to_dart_domain(domain);
 
+	for_each_stream_map(i, cfg, stream_map)
+		if (stream_map->dart->live_mtp)
+			return -EBUSY;
+
 	for_each_stream_map(i, cfg, stream_map)
 		WARN_ON(pm_runtime_get_sync(stream_map->dart->dev) < 0);
 
@@ -2101,6 +2110,10 @@ static int apple_dart_attach_dev_blocked(struct iommu_domain *domain,
 	struct apple_dart_stream_map *stream_map;
 	int i;
 
+	for_each_stream_map(i, cfg, stream_map)
+		if (stream_map->dart->live_mtp)
+			return -EBUSY;
+
 	if (cfg->locked)
 		return -EINVAL;
 
@@ -2528,6 +2541,8 @@ static int apple_dart_def_domain_type(struct device *dev)
 {
 	struct apple_dart_master_cfg *cfg = dev_iommu_priv_get(dev);
 
+	if (cfg->stream_maps[0].dart->live_mtp)
+		return IOMMU_DOMAIN_IDENTITY;
 	if (cfg->stream_maps[0].dart->pgsize > PAGE_SIZE)
 		return IOMMU_DOMAIN_IDENTITY;
 	if (!cfg->supports_bypass)
@@ -3189,6 +3204,25 @@ static int apple_dart_probe(struct platform_device *pdev)
 		goto err_clk_disable;
 	}
 
+	/* A live MTP epoch must never lose its firmware DMA addresses. */
+	if (of_property_present(dev->of_node, "apple,bypass-handoff-streams")) {
+		u32 stream;
+
+		if (!of_machine_is_compatible("apple,j613") ||
+		    !of_device_is_compatible(dev->of_node, "apple,t8122-dart") ||
+		    res->start != 0x2fa808000ULL || !dart->supports_bypass ||
+		    of_property_count_u32_elems(dev->of_node,
+					    "apple,bypass-handoff-streams") != 1 ||
+		    of_property_read_u32(dev->of_node, "apple,bypass-handoff-streams",
+					 &stream) ||
+		    stream != 1 || stream >= dart->num_streams ||
+		    apple_dart_readl(dart, DART_TCR(dart, stream)) != dart->hw->tcr_bypass) {
+			ret = -EINVAL;
+			goto err_clk_disable;
+		}
+		dart->live_mtp = true;
+	}
+
 	ret = apple_dart_read_remaps(dart);
 	if (ret)
 		goto err_clk_disable;
@@ -3204,7 +3238,7 @@ static int apple_dart_probe(struct platform_device *pdev)
 	dart->fw_mirror = dart->locked && !dart->fw_handoff &&
 		(of_device_is_compatible(dev->of_node, "apple,t8140-dart") ||
 		 of_device_is_compatible(dev->of_node, "apple,t8142-dart"));
-	if (!dart->locked) {
+	if (!dart->locked && !dart->live_mtp) {
 		ret = apple_dart_hw_reset(dart);
 		if (ret)
 			goto err_clk_disable;
@@ -3354,15 +3388,16 @@ static void apple_dart_remove(struct platform_device *pdev)
 	 * A command issued then never completes. The next probe resets the
 	 * block after that clock is running again.
 	 */
-	if (!dart->locked && !READ_ONCE(dart->commands_gated))
+	if (!dart->locked && !dart->live_mtp && !READ_ONCE(dart->commands_gated))
 		apple_dart_hw_reset(dart);
 
 	free_irq(dart->irq, dart);
 
 	iommu_device_unregister(&dart->iommu);
 	iommu_device_sysfs_remove(&dart->iommu);
 
-	clk_bulk_disable_unprepare(dart->num_clks, dart->clks);
+	if (!dart->live_mtp)
+		clk_bulk_disable_unprepare(dart->num_clks, dart->clks);
 }
 
 static const struct apple_dart_hw apple_dart_hw_t8103 = {
@@ -3478,6 +3513,9 @@ static __maybe_unused int apple_dart_suspend(struct device *dev)
 	struct apple_dart *dart = dev_get_drvdata(dev);
 	unsigned int sid, idx;
 
+	if (dart->live_mtp)
+		return -EBUSY;
+
 	dart->tunnel_state_restored = false;
 	if (READ_ONCE(dart->commands_gated))
 		return 0;
@@ -3627,7 +3665,45 @@ static __maybe_unused int apple_dart_resume(struct device *dev)
 	return ret;
 }
 
-static DEFINE_RUNTIME_DEV_PM_OPS(apple_dart_pm_ops, apple_dart_suspend, apple_dart_resume, NULL);
+/* The adopted MTP stays live: system s2idle must retain, never reset it. */
+static int apple_dart_system_suspend(struct device *dev)
+{
+	struct apple_dart *dart = dev_get_drvdata(dev);
+
+	if (!dart->live_mtp)
+		return pm_runtime_force_suspend(dev);
+	if (pm_suspend_target_state != PM_SUSPEND_TO_IDLE)
+		return -EBUSY;
+	if (apple_dart_readl(dart, DART_TCR(dart, 1)) != dart->hw->tcr_bypass)
+		return -EIO;
+	/* PMGR's ACTIVE_WAKEUP domains and their ancestors must stay powered. */
+	device_set_awake_path(dev);
+	dart->live_mtp_sleep = true;
+	dev_dbg(dev, "live MTP s2idle: retaining clocks, supplier power and bypass stream 1\n");
+	return 0;
+}
+
+static int apple_dart_system_resume(struct device *dev)
+{
+	struct apple_dart *dart = dev_get_drvdata(dev);
+
+	if (!dart->live_mtp)
+		return pm_runtime_force_resume(dev);
+	if (!dart->live_mtp_sleep)
+		return 0;
+	dart->live_mtp_sleep = false;
+	if (apple_dart_readl(dart, DART_TCR(dart, 1)) != dart->hw->tcr_bypass) {
+		dev_err(dev, "live MTP bypass lost across s2idle; refusing reset of inherited DMA\n");
+		return -EIO;
+	}
+	dev_dbg(dev, "live MTP s2idle: bypass retained; no reset or invalidate\n");
+	return 0;
+}
+
+static const struct dev_pm_ops apple_dart_pm_ops = {
+	RUNTIME_PM_OPS(apple_dart_suspend, apple_dart_resume, NULL)
+	SYSTEM_SLEEP_PM_OPS(apple_dart_system_suspend, apple_dart_system_resume)
+};
 
 static const struct of_device_id apple_dart_of_match[] = {
 	{ .compatible = "apple,t8103-dart", .data = &apple_dart_hw_t8103 },

drivers/soc/apple/rtkit-helper.c

@@ -11,6 +11,8 @@
 #include <linux/of.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
+#include <linux/pm_wakeup.h>
+#include <linux/suspend.h>
 #include <linux/soc/apple/rtkit.h>
 #include <linux/string.h>
 
@@ -193,15 +195,52 @@ static void apple_rtkit_helper_remove(struct platform_device *pdev)
 	writel_relaxed(0, helper->asc_base + APPLE_ASC_CPU_CONTROL);
 }
 
+static int apple_rtkit_helper_suspend(struct device *dev)
+{
+	struct apple_rtkit_helper *helper = dev_get_drvdata(dev);
+
+	if (!helper->adopted || !of_machine_is_compatible("apple,j613"))
+		return 0;
+	if (pm_suspend_target_state != PM_SUSPEND_TO_IDLE)
+		return -EBUSY;
+	if (!(readl(helper->asc_base + APPLE_ASC_CPU_CONTROL) & APPLE_ASC_CPU_CONTROL_RUN))
+		return -EHOSTDOWN;
+	/* mtp-live-v1 cannot be restarted: keep its ASC suppliers awake. */
+	device_set_awake_path(dev);
+	dev_dbg(dev, "adopted MTP s2idle: retaining ASC RUN and firmware session\n");
+	return 0;
+}
+
+static int apple_rtkit_helper_resume(struct device *dev)
+{
+	struct apple_rtkit_helper *helper = dev_get_drvdata(dev);
+
+	if (!helper->adopted || !of_machine_is_compatible("apple,j613"))
+		return 0;
+	if (!(readl(helper->asc_base + APPLE_ASC_CPU_CONTROL) & APPLE_ASC_CPU_CONTROL_RUN)) {
+		dev_err(dev, "adopted MTP lost ASC RUN; refusing firmware restart\n");
+		return -EHOSTDOWN;
+	}
+	dev_dbg(dev, "adopted MTP s2idle: ASC RUN retained, no INIT\n");
+	return 0;
+}
+
+static const struct dev_pm_ops apple_rtkit_helper_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(apple_rtkit_helper_suspend, apple_rtkit_helper_resume)
+};
+
 static const struct of_device_id apple_rtkit_helper_of_match[] = {
 	{ .compatible = "apple,rtk-helper-asc4" },
+	/* J613/J615 25G83 DTs omit the generic fallback (see t8122-j613-25g83.dts). */
+	{ .compatible = "apple,t8122-rtk-helper-asc4" },
 	{},
 };
 MODULE_DEVICE_TABLE(of, apple_rtkit_helper_of_match);
 
 static struct platform_driver apple_rtkit_helper_driver = {
 	.driver = {
 		.name = "rtkit-helper",
+		.pm = pm_sleep_ptr(&apple_rtkit_helper_pm_ops),
 		.of_match_table = apple_rtkit_helper_of_match,
 	},
 	.probe = apple_rtkit_helper_probe,

tools/asahi/j613-mtp-s2idle-tests.py

@@ -0,0 +1,61 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: GPL-2.0-only
+"""Actual system PM callbacks, synthetic register/PM boundaries; no device access."""
+from pathlib import Path
+import subprocess,tempfile
+R=Path(__file__).resolve().parents[2]
+def fn(s,n):
+ a=s.index('static int '+n+'(');b=s.index('\n}',a)+2;return s[a:b]
+s=(R/'drivers/iommu/apple-dart.c').read_text();h=(R/'drivers/soc/apple/rtkit-helper.c').read_text()
+assert 'if (dart->live_mtp)\n\t\treturn -EBUSY;' in s
+pre=r'''
+#include <assert.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <errno.h>
+#define dev_dbg(...) ((void)0)
+#define dev_err(...) ((void)0)
+#define DART_TCR(d,s) (s)
+#define APPLE_ASC_CPU_CONTROL 0x44
+#define APPLE_ASC_CPU_CONTROL_RUN 16
+#define PM_SUSPEND_TO_IDLE 1
+static int pm_suspend_target_state=1;
+struct device {void *data;bool awake;};
+struct hw {unsigned tcr_bypass;};
+struct apple_dart {bool live_mtp,live_mtp_sleep;struct hw *hw;unsigned tcr;};
+struct apple_rtkit_helper {bool adopted;unsigned char *asc_base;};
+static void *dev_get_drvdata(struct device *d){return d->data;}
+static unsigned apple_dart_readl(struct apple_dart *d,unsigned sid){assert(sid==1);return d->tcr;}
+static void device_set_awake_path(struct device *d){d->awake=true;}
+static unsigned forced_suspend,forced_resume;
+static int pm_runtime_force_suspend(struct device *d){forced_suspend++;return 7;}
+static int pm_runtime_force_resume(struct device *d){forced_resume++;return 8;}
+static bool of_machine_is_compatible(const char *s){return true;}
+static unsigned readl(void *p){return *(unsigned *)p;}
+'''
+body=fn(s,'apple_dart_system_suspend')+fn(s,'apple_dart_system_resume')+fn(h,'apple_rtkit_helper_suspend')+fn(h,'apple_rtkit_helper_resume')
+for forbidden in ['writel','hw_reset','invalidate_tlb','apple_rtkit_wake','apple_rtkit_boot','apple_rtkit_quiesce']:
+ assert forbidden not in body,forbidden
+checks=r'''
+int main(void){
+ struct hw hw={.tcr_bypass=3};struct apple_dart a={.live_mtp=true,.hw=&hw,.tcr=3};struct device d={.data=&a};
+ assert(!apple_dart_system_suspend(&d)&&d.awake&&a.live_mtp_sleep);
+ assert(!apple_dart_system_resume(&d)&&!a.live_mtp_sleep&&a.tcr==3&&!forced_suspend&&!forced_resume);
+ // Abort unwind is the same retained transaction, and can be repeated.
+ assert(!apple_dart_system_suspend(&d));assert(!apple_dart_system_resume(&d));
+ pm_suspend_target_state=2;assert(apple_dart_system_suspend(&d)==-EBUSY);pm_suspend_target_state=1;
+ a.tcr=0;assert(apple_dart_system_suspend(&d)==-EIO);a.tcr=3;
+ assert(!apple_dart_system_suspend(&d));a.tcr=0;assert(apple_dart_system_resume(&d)==-EIO&&a.tcr==0);
+ a.live_mtp=false;assert(apple_dart_system_suspend(&d)==7&&apple_dart_system_resume(&d)==8);
+ unsigned regs[32]={0};struct apple_rtkit_helper h={.adopted=true,.asc_base=(void *)regs};d.data=&h;d.awake=false;
+ regs[0x44/4]=16;assert(!apple_rtkit_helper_suspend(&d)&&d.awake);assert(!apple_rtkit_helper_resume(&d));
+ regs[0x44/4]=0;assert(apple_rtkit_helper_resume(&d)==-EHOSTDOWN&&!regs[0x44/4]);
+ assert(apple_rtkit_helper_suspend(&d)==-EHOSTDOWN);
+ h.adopted=false;assert(!apple_rtkit_helper_suspend(&d)&&!apple_rtkit_helper_resume(&d));
+}
+'''
+with tempfile.TemporaryDirectory() as t:
+ p=Path(t)/'pm.c';p.write_text(pre+body+checks)
+ subprocess.run(['clang','-std=gnu11','-Wall','-Werror','-fsanitize=address,undefined',str(p),'-o',str(p.with_suffix(''))],check=True)
+ subprocess.run([str(p.with_suffix(''))],check=True)
+print('PASS actual MTP/DART system PM: retained normal/abort cycles, runtime delegation, non-s2idle refusal, lost bypass/RUN refuses without reset/INIT')

tools/aurora-ci/host-tests.json

@@ -2282,6 +2282,14 @@
     "{output}"
    ],
    "note": "Build only the host Kconfig tool in an isolated output directory; check all built-in/module dependency combinations."
+  },
+  {
+   "name": "tools/asahi/j613-mtp-s2idle-tests.py",
+   "group": "tools",
+   "argv": [
+    "python3",
+    "tools/asahi/j613-mtp-s2idle-tests.py"
+   ]
   }
  ],
  "helpers": {