Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 463 insertions, 0 deletions

diff --git a/drivers/soc/apple/mailbox.c b/drivers/soc/apple/mailbox.c
new file mode 100644
index 000000000..5c4845518
--- /dev/null
+++ b/drivers/soc/apple/mailbox.c
@@ -0,0 +1,463 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple mailbox driver
+ *
+ * Copyright The Asahi Linux Contributors
+ *
+ * This driver adds support for two mailbox variants (called ASC and M3 by
+ * Apple) found in Apple SoCs such as the M1. It consists of two FIFOs used to
+ * exchange 64+32 bit messages between the main CPU and a co-processor.
+ * Various coprocessors implement different IPC protocols based on these simple
+ * messages and shared memory buffers.
+ *
+ * Both the main CPU and the co-processor see the same set of registers but
+ * the first FIFO (A2I) is always used to transfer messages from the application
+ * processor (us) to the I/O processor and the second one (I2A) for the
+ * other direction.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include "mailbox.h"
+
+#define APPLE_ASC_MBOX_CONTROL_FULL BIT(16)
+#define APPLE_ASC_MBOX_CONTROL_EMPTY BIT(17)
+
+#define APPLE_ASC_MBOX_A2I_CONTROL 0x110
+#define APPLE_ASC_MBOX_A2I_SEND0 0x800
+#define APPLE_ASC_MBOX_A2I_SEND1 0x808
+#define APPLE_ASC_MBOX_A2I_RECV0 0x810
+#define APPLE_ASC_MBOX_A2I_RECV1 0x818
+
+#define APPLE_ASC_MBOX_I2A_CONTROL 0x114
+#define APPLE_ASC_MBOX_I2A_SEND0 0x820
+#define APPLE_ASC_MBOX_I2A_SEND1 0x828
+#define APPLE_ASC_MBOX_I2A_RECV0 0x830
+#define APPLE_ASC_MBOX_I2A_RECV1 0x838
+
+#define APPLE_T8015_MBOX_A2I_CONTROL	0x108
+#define APPLE_T8015_MBOX_I2A_CONTROL	0x10c
+
+#define APPLE_M3_MBOX_CONTROL_FULL BIT(16)
+#define APPLE_M3_MBOX_CONTROL_EMPTY BIT(17)
+
+#define APPLE_M3_MBOX_A2I_CONTROL 0x50
+#define APPLE_M3_MBOX_A2I_SEND0 0x60
+#define APPLE_M3_MBOX_A2I_SEND1 0x68
+#define APPLE_M3_MBOX_A2I_RECV0 0x70
+#define APPLE_M3_MBOX_A2I_RECV1 0x78
+
+#define APPLE_M3_MBOX_I2A_CONTROL 0x80
+#define APPLE_M3_MBOX_I2A_SEND0 0x90
+#define APPLE_M3_MBOX_I2A_SEND1 0x98
+#define APPLE_M3_MBOX_I2A_RECV0 0xa0
+#define APPLE_M3_MBOX_I2A_RECV1 0xa8
+
+#define APPLE_M3_MBOX_IRQ_ENABLE 0x48
+#define APPLE_M3_MBOX_IRQ_ACK 0x4c
+#define APPLE_M3_MBOX_IRQ_A2I_EMPTY BIT(0)
+#define APPLE_M3_MBOX_IRQ_A2I_NOT_EMPTY BIT(1)
+#define APPLE_M3_MBOX_IRQ_I2A_EMPTY BIT(2)
+#define APPLE_M3_MBOX_IRQ_I2A_NOT_EMPTY BIT(3)
+
+#define APPLE_MBOX_MSG1_OUTCNT GENMASK(56, 52)
+#define APPLE_MBOX_MSG1_INCNT GENMASK(51, 48)
+#define APPLE_MBOX_MSG1_OUTPTR GENMASK(47, 44)
+#define APPLE_MBOX_MSG1_INPTR GENMASK(43, 40)
+#define APPLE_MBOX_MSG1_MSG GENMASK(31, 0)
+
+#define APPLE_MBOX_TX_TIMEOUT 500
+
+struct apple_mbox_hw {
+	unsigned int control_full;
+	unsigned int control_empty;
+
+	unsigned int a2i_control;
+	unsigned int a2i_send0;
+	unsigned int a2i_send1;
+
+	unsigned int i2a_control;
+	unsigned int i2a_recv0;
+	unsigned int i2a_recv1;
+
+	bool has_irq_controls;
+	unsigned int irq_enable;
+	unsigned int irq_ack;
+	unsigned int irq_bit_recv_not_empty;
+	unsigned int irq_bit_send_empty;
+};
+
+int apple_mbox_send(struct apple_mbox *mbox, const struct apple_mbox_msg msg,
+		    bool atomic)
+{
+	unsigned long flags;
+	int ret;
+	u32 mbox_ctrl;
+	long t;
+
+	spin_lock_irqsave(&mbox->tx_lock, flags);
+	mbox_ctrl = readl_relaxed(mbox->regs + mbox->hw->a2i_control);
+
+	while (mbox_ctrl & mbox->hw->control_full) {
+		if (atomic) {
+			ret = readl_poll_timeout_atomic(
+				mbox->regs + mbox->hw->a2i_control, mbox_ctrl,
+				!(mbox_ctrl & mbox->hw->control_full), 100,
+				APPLE_MBOX_TX_TIMEOUT * 1000);
+
+			if (ret) {
+				spin_unlock_irqrestore(&mbox->tx_lock, flags);
+				return ret;
+			}
+
+			break;
+		}
+		/*
+		 * The interrupt is level triggered and will keep firing as long as the
+		 * FIFO is empty. It will also keep firing if the FIFO was empty
+		 * at any point in the past until it has been acknowledged at the
+		 * mailbox level. By acknowledging it here we can ensure that we will
+		 * only get the interrupt once the FIFO has been cleared again.
+		 * If the FIFO is already empty before the ack it will fire again
+		 * immediately after the ack.
+		 */
+		if (mbox->hw->has_irq_controls) {
+			writel_relaxed(mbox->hw->irq_bit_send_empty,
+				       mbox->regs + mbox->hw->irq_ack);
+		}
+		enable_irq(mbox->irq_send_empty);
+		reinit_completion(&mbox->tx_empty);
+		spin_unlock_irqrestore(&mbox->tx_lock, flags);
+
+		t = wait_for_completion_interruptible_timeout(
+			&mbox->tx_empty,
+			msecs_to_jiffies(APPLE_MBOX_TX_TIMEOUT));
+		if (t < 0)
+			return t;
+		else if (t == 0)
+			return -ETIMEDOUT;
+
+		spin_lock_irqsave(&mbox->tx_lock, flags);
+		mbox_ctrl = readl_relaxed(mbox->regs + mbox->hw->a2i_control);
+	}
+
+	writeq_relaxed(msg.msg0, mbox->regs + mbox->hw->a2i_send0);
+	writeq_relaxed(FIELD_PREP(APPLE_MBOX_MSG1_MSG, msg.msg1),
+		       mbox->regs + mbox->hw->a2i_send1);
+
+	spin_unlock_irqrestore(&mbox->tx_lock, flags);
+
+	return 0;
+}
+EXPORT_SYMBOL(apple_mbox_send);
+
+static irqreturn_t apple_mbox_send_empty_irq(int irq, void *data)
+{
+	struct apple_mbox *mbox = data;
+
+	/*
+	 * We don't need to acknowledge the interrupt at the mailbox level
+	 * here even if supported by the hardware. It will keep firing but that
+	 * doesn't matter since it's disabled at the main interrupt controller.
+	 * apple_mbox_send will acknowledge it before enabling
+	 * it at the main controller again.
+	 */
+	spin_lock(&mbox->tx_lock);
+	disable_irq_nosync(mbox->irq_send_empty);
+	complete(&mbox->tx_empty);
+	spin_unlock(&mbox->tx_lock);
+
+	return IRQ_HANDLED;
+}
+
+static int apple_mbox_poll_locked(struct apple_mbox *mbox)
+{
+	struct apple_mbox_msg msg;
+	int ret = 0;
+
+	u32 mbox_ctrl = readl_relaxed(mbox->regs + mbox->hw->i2a_control);
+
+	while (!(mbox_ctrl & mbox->hw->control_empty)) {
+		msg.msg0 = readq_relaxed(mbox->regs + mbox->hw->i2a_recv0);
+		msg.msg1 = FIELD_GET(
+			APPLE_MBOX_MSG1_MSG,
+			readq_relaxed(mbox->regs + mbox->hw->i2a_recv1));
+
+		mbox->rx(mbox, msg, mbox->cookie);
+		ret++;
+		mbox_ctrl = readl_relaxed(mbox->regs + mbox->hw->i2a_control);
+	}
+
+	/*
+	 * The interrupt will keep firing even if there are no more messages
+	 * unless we also acknowledge it at the mailbox level here.
+	 * There's no race if a message comes in between the check in the while
+	 * loop above and the ack below: If a new messages arrives inbetween
+	 * those two the interrupt will just fire again immediately after the
+	 * ack since it's level triggered.
+	 */
+	if (mbox->hw->has_irq_controls) {
+		writel_relaxed(mbox->hw->irq_bit_recv_not_empty,
+			       mbox->regs + mbox->hw->irq_ack);
+	}
+
+	return ret;
+}
+
+static irqreturn_t apple_mbox_recv_irq(int irq, void *data)
+{
+	struct apple_mbox *mbox = data;
+
+	spin_lock(&mbox->rx_lock);
+	apple_mbox_poll_locked(mbox);
+	spin_unlock(&mbox->rx_lock);
+
+	return IRQ_HANDLED;
+}
+
+int apple_mbox_poll(struct apple_mbox *mbox)
+{
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&mbox->rx_lock, flags);
+	ret = apple_mbox_poll_locked(mbox);
+	spin_unlock_irqrestore(&mbox->rx_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(apple_mbox_poll);
+
+int apple_mbox_start(struct apple_mbox *mbox)
+{
+	int ret;
+
+	if (mbox->active)
+		return 0;
+
+	ret = pm_runtime_resume_and_get(mbox->dev);
+	if (ret)
+		return ret;
+
+	/*
+	 * Only some variants of this mailbox HW provide interrupt control
+	 * at the mailbox level. We therefore need to handle enabling/disabling
+	 * interrupts at the main interrupt controller anyway for hardware that
+	 * doesn't. Just always keep the interrupts we care about enabled at
+	 * the mailbox level so that both hardware revisions behave almost
+	 * the same.
+	 */
+	if (mbox->hw->has_irq_controls) {
+		writel_relaxed(mbox->hw->irq_bit_recv_not_empty |
+				       mbox->hw->irq_bit_send_empty,
+			       mbox->regs + mbox->hw->irq_enable);
+	}
+
+	enable_irq(mbox->irq_recv_not_empty);
+	mbox->active = true;
+	return 0;
+}
+EXPORT_SYMBOL(apple_mbox_start);
+
+void apple_mbox_stop(struct apple_mbox *mbox)
+{
+	if (!mbox->active)
+		return;
+
+	mbox->active = false;
+	disable_irq(mbox->irq_recv_not_empty);
+	pm_runtime_mark_last_busy(mbox->dev);
+	pm_runtime_put_autosuspend(mbox->dev);
+}
+EXPORT_SYMBOL(apple_mbox_stop);
+
+struct apple_mbox *apple_mbox_get(struct device *dev, int index)
+{
+	struct of_phandle_args args;
+	struct platform_device *pdev;
+	struct apple_mbox *mbox;
+	int ret;
+
+	ret = of_parse_phandle_with_args(dev->of_node, "mboxes", "#mbox-cells",
+					 index, &args);
+	if (ret || !args.np)
+		return ERR_PTR(ret);
+
+	pdev = of_find_device_by_node(args.np);
+	of_node_put(args.np);
+
+	if (!pdev)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	mbox = platform_get_drvdata(pdev);
+	if (!mbox) {
+		mbox = ERR_PTR(-EPROBE_DEFER);
+		goto out_put_pdev;
+	}
+
+	if (!device_link_add(dev, &pdev->dev, DL_FLAG_AUTOREMOVE_CONSUMER)) {
+		mbox = ERR_PTR(-ENODEV);
+		goto out_put_pdev;
+	}
+
+out_put_pdev:
+	put_device(&pdev->dev);
+
+	return mbox;
+}
+EXPORT_SYMBOL(apple_mbox_get);
+
+struct apple_mbox *apple_mbox_get_byname(struct device *dev, const char *name)
+{
+	int index;
+
+	index = of_property_match_string(dev->of_node, "mbox-names", name);
+	if (index < 0)
+		return ERR_PTR(index);
+
+	return apple_mbox_get(dev, index);
+}
+EXPORT_SYMBOL(apple_mbox_get_byname);
+
+static int apple_mbox_probe(struct platform_device *pdev)
+{
+	int ret;
+	char *irqname;
+	struct apple_mbox *mbox;
+	struct device *dev = &pdev->dev;
+
+	mbox = devm_kzalloc(dev, sizeof(*mbox), GFP_KERNEL);
+	if (!mbox)
+		return -ENOMEM;
+
+	mbox->dev = &pdev->dev;
+	mbox->hw = of_device_get_match_data(dev);
+	if (!mbox->hw)
+		return -EINVAL;
+
+	mbox->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(mbox->regs))
+		return PTR_ERR(mbox->regs);
+
+	mbox->irq_recv_not_empty =
+		platform_get_irq_byname(pdev, "recv-not-empty");
+	if (mbox->irq_recv_not_empty < 0)
+		return -ENODEV;
+
+	mbox->irq_send_empty = platform_get_irq_byname(pdev, "send-empty");
+	if (mbox->irq_send_empty < 0)
+		return -ENODEV;
+
+	spin_lock_init(&mbox->rx_lock);
+	spin_lock_init(&mbox->tx_lock);
+	init_completion(&mbox->tx_empty);
+
+	irqname = devm_kasprintf(dev, GFP_KERNEL, "%s-recv", dev_name(dev));
+	if (!irqname)
+		return -ENOMEM;
+
+	ret = devm_request_irq(dev, mbox->irq_recv_not_empty,
+			       apple_mbox_recv_irq,
+			       IRQF_NO_AUTOEN | IRQF_NO_SUSPEND, irqname, mbox);
+	if (ret)
+		return ret;
+
+	irqname = devm_kasprintf(dev, GFP_KERNEL, "%s-send", dev_name(dev));
+	if (!irqname)
+		return -ENOMEM;
+
+	ret = devm_request_irq(dev, mbox->irq_send_empty,
+			       apple_mbox_send_empty_irq,
+			       IRQF_NO_AUTOEN | IRQF_NO_SUSPEND, irqname, mbox);
+	if (ret)
+		return ret;
+
+	ret = devm_pm_runtime_enable(dev);
+	if (ret)
+		return ret;
+
+	platform_set_drvdata(pdev, mbox);
+	return 0;
+}
+
+static const struct apple_mbox_hw apple_mbox_t8015_hw = {
+	.control_full = APPLE_ASC_MBOX_CONTROL_FULL,
+	.control_empty = APPLE_ASC_MBOX_CONTROL_EMPTY,
+
+	.a2i_control = APPLE_T8015_MBOX_A2I_CONTROL,
+	.a2i_send0 = APPLE_ASC_MBOX_A2I_SEND0,
+	.a2i_send1 = APPLE_ASC_MBOX_A2I_SEND1,
+
+	.i2a_control = APPLE_T8015_MBOX_I2A_CONTROL,
+	.i2a_recv0 = APPLE_ASC_MBOX_I2A_RECV0,
+	.i2a_recv1 = APPLE_ASC_MBOX_I2A_RECV1,
+
+	.has_irq_controls = false,
+};
+
+static const struct apple_mbox_hw apple_mbox_asc_hw = {
+	.control_full = APPLE_ASC_MBOX_CONTROL_FULL,
+	.control_empty = APPLE_ASC_MBOX_CONTROL_EMPTY,
+
+	.a2i_control = APPLE_ASC_MBOX_A2I_CONTROL,
+	.a2i_send0 = APPLE_ASC_MBOX_A2I_SEND0,
+	.a2i_send1 = APPLE_ASC_MBOX_A2I_SEND1,
+
+	.i2a_control = APPLE_ASC_MBOX_I2A_CONTROL,
+	.i2a_recv0 = APPLE_ASC_MBOX_I2A_RECV0,
+	.i2a_recv1 = APPLE_ASC_MBOX_I2A_RECV1,
+
+	.has_irq_controls = false,
+};
+
+static const struct apple_mbox_hw apple_mbox_m3_hw = {
+	.control_full = APPLE_M3_MBOX_CONTROL_FULL,
+	.control_empty = APPLE_M3_MBOX_CONTROL_EMPTY,
+
+	.a2i_control = APPLE_M3_MBOX_A2I_CONTROL,
+	.a2i_send0 = APPLE_M3_MBOX_A2I_SEND0,
+	.a2i_send1 = APPLE_M3_MBOX_A2I_SEND1,
+
+	.i2a_control = APPLE_M3_MBOX_I2A_CONTROL,
+	.i2a_recv0 = APPLE_M3_MBOX_I2A_RECV0,
+	.i2a_recv1 = APPLE_M3_MBOX_I2A_RECV1,
+
+	.has_irq_controls = true,
+	.irq_enable = APPLE_M3_MBOX_IRQ_ENABLE,
+	.irq_ack = APPLE_M3_MBOX_IRQ_ACK,
+	.irq_bit_recv_not_empty = APPLE_M3_MBOX_IRQ_I2A_NOT_EMPTY,
+	.irq_bit_send_empty = APPLE_M3_MBOX_IRQ_A2I_EMPTY,
+};
+
+static const struct of_device_id apple_mbox_of_match[] = {
+	{ .compatible = "apple,asc-mailbox-v4", .data = &apple_mbox_asc_hw },
+	{ .compatible = "apple,t8015-asc-mailbox", .data = &apple_mbox_t8015_hw },
+	{ .compatible = "apple,m3-mailbox-v2", .data = &apple_mbox_m3_hw },
+	{}
+};
+MODULE_DEVICE_TABLE(of, apple_mbox_of_match);
+
+static struct platform_driver apple_mbox_driver = {
+	.driver = {
+		.name = "apple-mailbox",
+		.of_match_table = apple_mbox_of_match,
+	},
+	.probe = apple_mbox_probe,
+};
+module_platform_driver(apple_mbox_driver);
+
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_AUTHOR("Sven Peter <sven@svenpeter.dev>");
+MODULE_DESCRIPTION("Apple Mailbox driver");