[v2,05/17] soc: qcom: ipa: clocking, interrupts, and memory

diff --git a/drivers/net/ipa/ipa_clock.c b/drivers/net/ipa/ipa_clock.c
new file mode 100644
index 000000000000..374491ea11cf
--- /dev/null
+++ b/drivers/net/ipa/ipa_clock.c
@@ -0,0 +1,313 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2018-2020 Linaro Ltd.
+ */
+
+#include <linux/atomic.h>
+#include <linux/mutex.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/interconnect.h>
+
+#include "ipa.h"
+#include "ipa_clock.h"
+#include "ipa_modem.h"
+
+/**
+ * DOC: IPA Clocking
+ *
+ * The "IPA Clock" manages both the IPA core clock and the interconnects
+ * (buses) the IPA depends on as a single logical entity.  A reference count
+ * is incremented by "get" operations and decremented by "put" operations.
+ * Transitions of that count from 0 to 1 result in the clock and interconnects
+ * being enabled, and transitions of the count from 1 to 0 cause them to be
+ * disabled.  We currently operate the core clock at a fixed clock rate, and
+ * all buses at a fixed average and peak bandwidth.  As more advanced IPA
+ * features are enabled, we can make better use of clock and bus scaling.
+ *
+ * An IPA clock reference must be held for any access to IPA hardware.
+ */
+
+#define	IPA_CORE_CLOCK_RATE		(75UL * 1000 * 1000)	/* Hz */
+
+/* Interconnect path bandwidths (each times 1000 bytes per second) */
+#define IPA_MEMORY_AVG			(80 * 1000)	/* 80 MBps */
+#define IPA_MEMORY_PEAK			(600 * 1000)
+
+#define IPA_IMEM_AVG			(80 * 1000)
+#define IPA_IMEM_PEAK			(350 * 1000)
+
+#define IPA_CONFIG_AVG			(40 * 1000)
+#define IPA_CONFIG_PEAK			(40 * 1000)
+
+/**
+ * struct ipa_clock - IPA clocking information
+ * @count:		Clocking reference count
+ * @mutex;		Protects clock enable/disable
+ * @core:		IPA core clock
+ * @memory_path:	Memory interconnect
+ * @imem_path:		Internal memory interconnect
+ * @config_path:	Configuration space interconnect
+ */
+struct ipa_clock {
+	atomic_t count;
+	struct mutex mutex; /* protects clock enable/disable */
+	struct clk *core;
+	struct icc_path *memory_path;
+	struct icc_path *imem_path;
+	struct icc_path *config_path;
+};
+
+static struct icc_path *
+ipa_interconnect_init_one(struct device *dev, const char *name)
+{
+	struct icc_path *path;
+
+	path = of_icc_get(dev, name);
+	if (IS_ERR(path))
+		dev_err(dev, "error %ld getting memory interconnect\n",
+			PTR_ERR(path));
+
+	return path;
+}
+
+/* Initialize interconnects required for IPA operation */
+static int ipa_interconnect_init(struct ipa_clock *clock, struct device *dev)
+{
+	struct icc_path *path;
+
+	path = ipa_interconnect_init_one(dev, "memory");
+	if (IS_ERR(path))
+		goto err_return;
+	clock->memory_path = path;
+
+	path = ipa_interconnect_init_one(dev, "imem");
+	if (IS_ERR(path))
+		goto err_memory_path_put;
+	clock->imem_path = path;
+
+	path = ipa_interconnect_init_one(dev, "config");
+	if (IS_ERR(path))
+		goto err_imem_path_put;
+	clock->config_path = path;
+
+	return 0;
+
+err_imem_path_put:
+	icc_put(clock->imem_path);
+err_memory_path_put:
+	icc_put(clock->memory_path);
+err_return:
+	return PTR_ERR(path);
+}
+
+/* Inverse of ipa_interconnect_init() */
+static void ipa_interconnect_exit(struct ipa_clock *clock)
+{
+	icc_put(clock->config_path);
+	icc_put(clock->imem_path);
+	icc_put(clock->memory_path);
+}
+
+/* Currently we only use one bandwidth level, so just "enable" interconnects */
+static int ipa_interconnect_enable(struct ipa *ipa)
+{
+	struct ipa_clock *clock = ipa->clock;
+	int ret;
+
+	ret = icc_set_bw(clock->memory_path, IPA_MEMORY_AVG, IPA_MEMORY_PEAK);
+	if (ret)
+		return ret;
+
+	ret = icc_set_bw(clock->imem_path, IPA_IMEM_AVG, IPA_IMEM_PEAK);
+	if (ret)
+		goto err_memory_path_disable;
+
+	ret = icc_set_bw(clock->config_path, IPA_CONFIG_AVG, IPA_CONFIG_PEAK);
+	if (ret)
+		goto err_imem_path_disable;
+
+	return 0;
+
+err_imem_path_disable:
+	(void)icc_set_bw(clock->imem_path, 0, 0);
+err_memory_path_disable:
+	(void)icc_set_bw(clock->memory_path, 0, 0);
+
+	return ret;
+}
+
+/* To disable an interconnect, we just its bandwidth to 0 */
+static int ipa_interconnect_disable(struct ipa *ipa)
+{
+	struct ipa_clock *clock = ipa->clock;
+	int ret;
+
+	ret = icc_set_bw(clock->memory_path, 0, 0);
+	if (ret)
+		return ret;
+
+	ret = icc_set_bw(clock->imem_path, 0, 0);
+	if (ret)
+		goto err_memory_path_reenable;
+
+	ret = icc_set_bw(clock->config_path, 0, 0);
+	if (ret)
+		goto err_imem_path_reenable;
+
+	return 0;
+
+err_imem_path_reenable:
+	(void)icc_set_bw(clock->imem_path, IPA_IMEM_AVG, IPA_IMEM_PEAK);
+err_memory_path_reenable:
+	(void)icc_set_bw(clock->memory_path, IPA_MEMORY_AVG, IPA_MEMORY_PEAK);
+
+	return ret;
+}
+
+/* Turn on IPA clocks, including interconnects */
+static int ipa_clock_enable(struct ipa *ipa)
+{
+	int ret;
+
+	ret = ipa_interconnect_enable(ipa);
+	if (ret)
+		return ret;
+
+	ret = clk_prepare_enable(ipa->clock->core);
+	if (ret)
+		ipa_interconnect_disable(ipa);
+
+	return ret;
+}
+
+/* Inverse of ipa_clock_enable() */
+static void ipa_clock_disable(struct ipa *ipa)
+{
+	clk_disable_unprepare(ipa->clock->core);
+	(void)ipa_interconnect_disable(ipa);
+}
+
+/* Get an IPA clock reference, but only if the reference count is
+ * already non-zero.  Returns true if the additional reference was
+ * added successfully, or false otherwise.
+ */
+bool ipa_clock_get_additional(struct ipa *ipa)
+{
+	return !!atomic_inc_not_zero(&ipa->clock->count);
+}
+
+/* Get an IPA clock reference.  If the reference count is non-zero, it is
+ * incremented and return is immediate.  Otherwise it is checked again
+ * under protection of the mutex, and if appropriate the clock (and
+ * interconnects) are enabled suspended endpoints (if any) are resumed
+ * before returning.
+ *
+ * Incrementing the reference count is intentionally deferred until
+ * after the clock is running and endpoints are resumed.
+ */
+void ipa_clock_get(struct ipa *ipa)
+{
+	struct ipa_clock *clock = ipa->clock;
+	int ret;
+
+	/* If the clock is running, just bump the reference count */
+	if (ipa_clock_get_additional(ipa))
+		return;
+
+	/* Otherwise get the mutex and check again */
+	mutex_lock(&clock->mutex);
+
+	/* A reference might have been added before we got the mutex. */
+	if (ipa_clock_get_additional(ipa))
+		goto out_mutex_unlock;
+
+	ret = ipa_clock_enable(ipa);
+	if (ret) {
+		dev_err(&ipa->pdev->dev, "error %d enabling IPA clock\n", ret);
+		goto out_mutex_unlock;
+	}
+
+	ipa_endpoint_resume(ipa);
+
+	atomic_inc(&clock->count);
+
+out_mutex_unlock:
+	mutex_unlock(&clock->mutex);
+}
+
+/* Attempt to remove an IPA clock reference.  If this represents the last
+ * reference, suspend endpoints and disable the clock (and interconnects)
+ * under protection of a mutex.
+ */
+void ipa_clock_put(struct ipa *ipa)
+{
+	struct ipa_clock *clock = ipa->clock;
+
+	/* If this is not the last reference there's nothing more to do */
+	if (!atomic_dec_and_mutex_lock(&clock->count, &clock->mutex))
+		return;
+
+	ipa_endpoint_suspend(ipa);
+
+	ipa_clock_disable(ipa);
+
+	mutex_unlock(&clock->mutex);
+}
+
+/* Initialize IPA clocking */
+struct ipa_clock *ipa_clock_init(struct device *dev)
+{
+	struct ipa_clock *clock;
+	struct clk *clk;
+	int ret;
+
+	clk = clk_get(dev, "core");
+	if (IS_ERR(clk)) {
+		dev_err(dev, "error %ld getting core clock\n", PTR_ERR(clk));
+		return ERR_CAST(clk);
+	}
+
+	ret = clk_set_rate(clk, IPA_CORE_CLOCK_RATE);
+	if (ret) {
+		dev_err(dev, "error %d setting core clock rate to %lu\n",
+			ret, IPA_CORE_CLOCK_RATE);
+		goto err_clk_put;
+	}
+
+	clock = kzalloc(sizeof(*clock), GFP_KERNEL);
+	if (!clock) {
+		ret = -ENOMEM;
+		goto err_clk_put;
+	}
+	clock->core = clk;
+
+	ret = ipa_interconnect_init(clock, dev);
+	if (ret)
+		goto err_kfree;
+
+	mutex_init(&clock->mutex);
+	atomic_set(&clock->count, 0);
+
+	return clock;
+
+err_kfree:
+	kfree(clock);
+err_clk_put:
+	clk_put(clk);
+
+	return ERR_PTR(ret);
+}
+
+/* Inverse of ipa_clock_init() */
+void ipa_clock_exit(struct ipa_clock *clock)
+{
+	struct clk *clk = clock->core;
+
+	WARN_ON(atomic_read(&clock->count) != 0);
+	mutex_destroy(&clock->mutex);
+	ipa_interconnect_exit(clock);
+	kfree(clock);
+	clk_put(clk);
+}
diff --git a/drivers/net/ipa/ipa_clock.h b/drivers/net/ipa/ipa_clock.h
new file mode 100644
index 000000000000..bc52b35e6bb2
--- /dev/null
+++ b/drivers/net/ipa/ipa_clock.h
@@ -0,0 +1,53 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2018-2020 Linaro Ltd.
+ */
+#ifndef _IPA_CLOCK_H_
+#define _IPA_CLOCK_H_
+
+struct device;
+
+struct ipa;
+
+/**
+ * ipa_clock_init() - Initialize IPA clocking
+ * @dev:	IPA device
+ *
+ * @Return:	A pointer to an ipa_clock structure, or a pointer-coded error
+ */
+struct ipa_clock *ipa_clock_init(struct device *dev);
+
+/**
+ * ipa_clock_exit() - Inverse of ipa_clock_init()
+ * @clock:	IPA clock pointer
+ */
+void ipa_clock_exit(struct ipa_clock *clock);
+
+/**
+ * ipa_clock_get() - Get an IPA clock reference
+ * @ipa:	IPA pointer
+ *
+ * This call blocks if this is the first reference.
+ */
+void ipa_clock_get(struct ipa *ipa);
+
+/**
+ * ipa_clock_get_additional() - Get an IPA clock reference if not first
+ * @ipa:	IPA pointer
+ *
+ * This returns immediately, and only takes a reference if not the first
+ */
+bool ipa_clock_get_additional(struct ipa *ipa);
+
+/**
+ * ipa_clock_put() - Drop an IPA clock reference
+ * @ipa:	IPA pointer
+ *
+ * This drops a clock reference.  If the last reference is being dropped,
+ * the clock is stopped and RX endpoints are suspended.  This call will
+ * not block unless the last reference is dropped.
+ */
+void ipa_clock_put(struct ipa *ipa);
+
+#endif /* _IPA_CLOCK_H_ */
diff --git a/drivers/net/ipa/ipa_interrupt.c b/drivers/net/ipa/ipa_interrupt.c
new file mode 100644
index 000000000000..90353987c45f
--- /dev/null
+++ b/drivers/net/ipa/ipa_interrupt.c
@@ -0,0 +1,253 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2014-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2018-2020 Linaro Ltd.
+ */
+
+/* DOC: IPA Interrupts
+ *
+ * The IPA has an interrupt line distinct from the interrupt used by the GSI
+ * code.  Whereas GSI interrupts are generally related to channel events (like
+ * transfer completions), IPA interrupts are related to other events related
+ * to the IPA.  Some of the IPA interrupts come from a microcontroller
+ * embedded in the IPA.  Each IPA interrupt type can be both masked and
+ * acknowledged independent of the others.
+ *
+ * Two of the IPA interrupts are initiated by the microcontroller.  A third
+ * can be generated to signal the need for a wakeup/resume when an IPA
+ * endpoint has been suspended.  There are other IPA events, but at this
+ * time only these three are supported.
+ */
+
+#include <linux/types.h>
+#include <linux/interrupt.h>
+
+#include "ipa.h"
+#include "ipa_clock.h"
+#include "ipa_reg.h"
+#include "ipa_endpoint.h"
+#include "ipa_interrupt.h"
+
+/**
+ * struct ipa_interrupt - IPA interrupt information
+ * @ipa:		IPA pointer
+ * @irq:		Linux IRQ number used for IPA interrupts
+ * @enabled:		Mask indicating which interrupts are enabled
+ * @handler:		Array of handlers indexed by IPA interrupt ID
+ */
+struct ipa_interrupt {
+	struct ipa *ipa;
+	u32 irq;
+	u32 enabled;
+	ipa_irq_handler_t handler[IPA_IRQ_COUNT];
+};
+
+/* Returns true if the interrupt type is associated with the microcontroller */
+static bool ipa_interrupt_uc(struct ipa_interrupt *interrupt, u32 irq_id)
+{
+	return irq_id == IPA_IRQ_UC_0 || irq_id == IPA_IRQ_UC_1;
+}
+
+/* Process a particular interrupt type that has been received */
+static void ipa_interrupt_process(struct ipa_interrupt *interrupt, u32 irq_id)
+{
+	bool uc_irq = ipa_interrupt_uc(interrupt, irq_id);
+	struct ipa *ipa = interrupt->ipa;
+	u32 mask = BIT(irq_id);
+
+	/* For microcontroller interrupts, clear the interrupt right away,
+	 * "to avoid clearing unhandled interrupts."
+	 */
+	if (uc_irq)
+		iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET);
+
+	if (irq_id < IPA_IRQ_COUNT && interrupt->handler[irq_id])
+		interrupt->handler[irq_id](interrupt->ipa, irq_id);
+
+	/* Clearing the SUSPEND_TX interrupt also clears the register
+	 * that tells us which suspended endpoint(s) caused the interrupt,
+	 * so defer clearing until after the handler has been called.
+	 */
+	if (!uc_irq)
+		iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET);
+}
+
+/* Process all IPA interrupt types that have been signaled */
+static void ipa_interrupt_process_all(struct ipa_interrupt *interrupt)
+{
+	struct ipa *ipa = interrupt->ipa;
+	u32 enabled = interrupt->enabled;
+	u32 mask;
+
+	/* The status register indicates which conditions are present,
+	 * including conditions whose interrupt is not enabled.  Handle
+	 * only the enabled ones.
+	 */
+	mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET);
+	while ((mask &= enabled)) {
+		do {
+			u32 irq_id = __ffs(mask);
+
+			mask ^= BIT(irq_id);
+
+			ipa_interrupt_process(interrupt, irq_id);
+		} while (mask);
+		mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET);
+	}
+}
+
+/* Threaded part of the IPA IRQ handler */
+static irqreturn_t ipa_isr_thread(int irq, void *dev_id)
+{
+	struct ipa_interrupt *interrupt = dev_id;
+
+	ipa_clock_get(interrupt->ipa);
+
+	ipa_interrupt_process_all(interrupt);
+
+	ipa_clock_put(interrupt->ipa);
+
+	return IRQ_HANDLED;
+}
+
+/* Hard part (i.e., "real" IRQ handler) of the IRQ handler */
+static irqreturn_t ipa_isr(int irq, void *dev_id)
+{
+	struct ipa_interrupt *interrupt = dev_id;
+	struct ipa *ipa = interrupt->ipa;
+	u32 mask;
+
+	mask = ioread32(ipa->reg_virt + IPA_REG_IRQ_STTS_OFFSET);
+	if (mask & interrupt->enabled)
+		return IRQ_WAKE_THREAD;
+
+	/* Nothing in the mask was supposed to cause an interrupt */
+	iowrite32(mask, ipa->reg_virt + IPA_REG_IRQ_CLR_OFFSET);
+
+	dev_err(&ipa->pdev->dev, "%s: unexpected interrupt, mask 0x%08x\n",
+		__func__, mask);
+
+	return IRQ_HANDLED;
+}
+
+/* Common function used to enable/disable TX_SUSPEND for an endpoint */
+static void ipa_interrupt_suspend_control(struct ipa_interrupt *interrupt,
+					  u32 endpoint_id, bool enable)
+{
+	struct ipa *ipa = interrupt->ipa;
+	u32 mask = BIT(endpoint_id);
+	u32 val;
+
+	/* assert(mask & ipa->available); */
+	val = ioread32(ipa->reg_virt + IPA_REG_SUSPEND_IRQ_EN_OFFSET);
+	if (enable)
+		val |= mask;
+	else
+		val &= ~mask;
+	iowrite32(val, ipa->reg_virt + IPA_REG_SUSPEND_IRQ_EN_OFFSET);
+}
+
+/* Enable TX_SUSPEND for an endpoint */
+void
+ipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt, u32 endpoint_id)
+{
+	ipa_interrupt_suspend_control(interrupt, endpoint_id, true);
+}
+
+/* Disable TX_SUSPEND for an endpoint */
+void
+ipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt, u32 endpoint_id)
+{
+	ipa_interrupt_suspend_control(interrupt, endpoint_id, false);
+}
+
+/* Clear the suspend interrupt for all endpoints that signaled it */
+void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt)
+{
+	struct ipa *ipa = interrupt->ipa;
+	u32 val;
+
+	val = ioread32(ipa->reg_virt + IPA_REG_IRQ_SUSPEND_INFO_OFFSET);
+	iowrite32(val, ipa->reg_virt + IPA_REG_SUSPEND_IRQ_CLR_OFFSET);
+}
+
+/* Simulate arrival of an IPA TX_SUSPEND interrupt */
+void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt)
+{
+	ipa_interrupt_process(interrupt, IPA_IRQ_TX_SUSPEND);
+}
+
+/* Add a handler for an IPA interrupt */
+void ipa_interrupt_add(struct ipa_interrupt *interrupt,
+		       enum ipa_irq_id ipa_irq, ipa_irq_handler_t handler)
+{
+	struct ipa *ipa = interrupt->ipa;
+
+	/* assert(ipa_irq < IPA_IRQ_COUNT); */
+	interrupt->handler[ipa_irq] = handler;
+
+	/* Update the IPA interrupt mask to enable it */
+	interrupt->enabled |= BIT(ipa_irq);
+	iowrite32(interrupt->enabled, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET);
+}
+
+/* Remove the handler for an IPA interrupt type */
+void
+ipa_interrupt_remove(struct ipa_interrupt *interrupt, enum ipa_irq_id ipa_irq)
+{
+	struct ipa *ipa = interrupt->ipa;
+
+	/* assert(ipa_irq < IPA_IRQ_COUNT); */
+	/* Update the IPA interrupt mask to disable it */
+	interrupt->enabled &= ~BIT(ipa_irq);
+	iowrite32(interrupt->enabled, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET);
+
+	interrupt->handler[ipa_irq] = NULL;
+}
+
+/* Set up the IPA interrupt framework */
+struct ipa_interrupt *ipa_interrupt_setup(struct ipa *ipa)
+{
+	struct device *dev = &ipa->pdev->dev;
+	struct ipa_interrupt *interrupt;
+	unsigned int irq;
+	int ret;
+
+	ret = platform_get_irq_byname(ipa->pdev, "ipa");
+	if (ret <= 0) {
+		dev_err(dev, "DT error %d getting \"ipa\" IRQ property\n",
+			ret);
+		return ERR_PTR(ret ? : -EINVAL);
+	}
+	irq = ret;
+
+	interrupt = kzalloc(sizeof(*interrupt), GFP_KERNEL);
+	if (!interrupt)
+		return ERR_PTR(-ENOMEM);
+	interrupt->ipa = ipa;
+	interrupt->irq = irq;
+
+	/* Start with all IPA interrupts disabled */
+	iowrite32(0, ipa->reg_virt + IPA_REG_IRQ_EN_OFFSET);
+
+	ret = request_threaded_irq(irq, ipa_isr, ipa_isr_thread, IRQF_ONESHOT,
+				   "ipa", interrupt);
+	if (ret) {
+		dev_err(dev, "error %d requesting \"ipa\" IRQ\n", ret);
+		goto err_kfree;
+	}
+
+	return interrupt;
+
+err_kfree:
+	kfree(interrupt);
+
+	return ERR_PTR(ret);
+}
+
+/* Tear down the IPA interrupt framework */
+void ipa_interrupt_teardown(struct ipa_interrupt *interrupt)
+{
+	free_irq(interrupt->irq, interrupt);
+	kfree(interrupt);
+}
diff --git a/drivers/net/ipa/ipa_interrupt.h b/drivers/net/ipa/ipa_interrupt.h
new file mode 100644
index 000000000000..d4f4c1c9f0b1
--- /dev/null
+++ b/drivers/net/ipa/ipa_interrupt.h
@@ -0,0 +1,117 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2018-2020 Linaro Ltd.
+ */
+#ifndef _IPA_INTERRUPT_H_
+#define _IPA_INTERRUPT_H_
+
+#include <linux/types.h>
+#include <linux/bits.h>
+
+struct ipa;
+struct ipa_interrupt;
+
+/**
+ * enum ipa_irq_id - IPA interrupt type
+ * @IPA_IRQ_UC_0:	Microcontroller event interrupt
+ * @IPA_IRQ_UC_1:	Microcontroller response interrupt
+ * @IPA_IRQ_TX_SUSPEND:	Data ready interrupt
+ *
+ * The data ready interrupt is signaled if data has arrived that is destined
+ * for an AP RX endpoint whose underlying GSI channel is suspended/stopped.
+ */
+enum ipa_irq_id {
+	IPA_IRQ_UC_0		= 2,
+	IPA_IRQ_UC_1		= 3,
+	IPA_IRQ_TX_SUSPEND	= 14,
+	IPA_IRQ_COUNT,		/* Number of interrupt types (not an index) */
+};
+
+/**
+ * typedef ipa_irq_handler_t - IPA interrupt handler function type
+ * @ipa:	IPA pointer
+ * @irq_id:	interrupt type
+ *
+ * Callback function registered by ipa_interrupt_add() to handle a specific
+ * IPA interrupt type
+ */
+typedef void (*ipa_irq_handler_t)(struct ipa *ipa, enum ipa_irq_id irq_id);
+
+/**
+ * ipa_interrupt_add() - Register a handler for an IPA interrupt type
+ * @irq_id:	IPA interrupt type
+ * @handler:	Handler function for the interrupt
+ *
+ * Add a handler for an IPA interrupt and enable it.  IPA interrupt
+ * handlers are run in threaded interrupt context, so are allowed to
+ * block.
+ */
+void ipa_interrupt_add(struct ipa_interrupt *interrupt, enum ipa_irq_id irq_id,
+		       ipa_irq_handler_t handler);
+
+/**
+ * ipa_interrupt_remove() - Remove the handler for an IPA interrupt type
+ * @interrupt:	IPA interrupt structure
+ * @irq_id:	IPA interrupt type
+ *
+ * Remove an IPA interrupt handler and disable it.
+ */
+void ipa_interrupt_remove(struct ipa_interrupt *interrupt,
+			  enum ipa_irq_id irq_id);
+
+/**
+ * ipa_interrupt_suspend_enable - Enable TX_SUSPEND for an endpoint
+ * @interrupt:		IPA interrupt structure
+ * @endpoint_id:	Endpoint whose interrupt should be enabled
+ *
+ * Note:  The "TX" in the name is from the perspective of the IPA hardware.
+ * A TX_SUSPEND interrupt arrives on an AP RX enpoint when packet data can't
+ * be delivered to the endpoint because it is suspended (or its underlying
+ * channel is stopped).
+ */
+void ipa_interrupt_suspend_enable(struct ipa_interrupt *interrupt,
+				  u32 endpoint_id);
+
+/**
+ * ipa_interrupt_suspend_disable - Disable TX_SUSPEND for an endpoint
+ * @interrupt:		IPA interrupt structure
+ * @endpoint_id:	Endpoint whose interrupt should be disabled
+ */
+void ipa_interrupt_suspend_disable(struct ipa_interrupt *interrupt,
+				   u32 endpoint_id);
+
+/**
+ * ipa_interrupt_suspend_clear_all - clear all suspend interrupts
+ * @interrupt:	IPA interrupt structure
+ *
+ * Clear the TX_SUSPEND interrupt for all endpoints that signaled it.
+ */
+void ipa_interrupt_suspend_clear_all(struct ipa_interrupt *interrupt);
+
+/**
+ * ipa_interrupt_simulate_suspend() - Simulate TX_SUSPEND IPA interrupt
+ * @interrupt:	IPA interrupt structure
+ *
+ * This calls the TX_SUSPEND interrupt handler, as if such an interrupt
+ * had been signaled.  This is needed to work around a hardware quirk
+ * that occurs if aggregation is active on an endpoint when its underlying
+ * channel is suspended.
+ */
+void ipa_interrupt_simulate_suspend(struct ipa_interrupt *interrupt);
+
+/**
+ * ipa_interrupt_setup() - Set up the IPA interrupt framework
+ * @ipa:	IPA pointer
+ *
+ * @Return:	Pointer to IPA SMP2P info, or a pointer-coded error
+ */
+struct ipa_interrupt *ipa_interrupt_setup(struct ipa *ipa);
+
+/**
+ * ipa_interrupt_teardown() - Tear down the IPA interrupt framework
+ * @interrupt:	IPA interrupt structure
+ */
+void ipa_interrupt_teardown(struct ipa_interrupt *interrupt);
+
+#endif /* _IPA_INTERRUPT_H_ */
diff --git a/drivers/net/ipa/ipa_mem.c b/drivers/net/ipa/ipa_mem.c
new file mode 100644
index 000000000000..42d2c29d9f0c
--- /dev/null
+++ b/drivers/net/ipa/ipa_mem.c
@@ -0,0 +1,314 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2019-2020 Linaro Ltd.
+ */
+
+#include <linux/types.h>
+#include <linux/bitfield.h>
+#include <linux/bug.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+
+#include "ipa.h"
+#include "ipa_reg.h"
+#include "ipa_cmd.h"
+#include "ipa_mem.h"
+#include "ipa_data.h"
+#include "ipa_table.h"
+#include "gsi_trans.h"
+
+/* "Canary" value placed between memory regions to detect overflow */
+#define IPA_MEM_CANARY_VAL		cpu_to_le32(0xdeadbeef)
+
+/* Add an immediate command to a transaction that zeroes a memory region */
+static void
+ipa_mem_zero_region_add(struct gsi_trans *trans, const struct ipa_mem *mem)
+{
+	struct ipa *ipa = container_of(trans->gsi, struct ipa, gsi);
+	dma_addr_t addr = ipa->zero_addr;
+
+	if (!mem->size)
+		return;
+
+	ipa_cmd_dma_shared_mem_add(trans, mem->offset, mem->size, addr, true);
+}
+
+/**
+ * ipa_mem_setup() - Set up IPA AP and modem shared memory areas
+ *
+ * Set up the shared memory regions in IPA local memory.  This involves
+ * zero-filling memory regions, and in the case of header memory, telling
+ * the IPA where it's located.
+ *
+ * This function performs the initial setup of this memory.  If the modem
+ * crashes, its regions are re-zeroed in ipa_mem_zero_modem().
+ *
+ * The AP informs the modem where its portions of memory are located
+ * in a QMI exchange that occurs at modem startup.
+ *
+ * @Return:	0 if successful, or a negative error code
+ */
+int ipa_mem_setup(struct ipa *ipa)
+{
+	dma_addr_t addr = ipa->zero_addr;
+	struct gsi_trans *trans;
+	u32 offset;
+	u16 size;
+
+	/* Get a transaction to define the header memory region and to zero
+	 * the processing context and modem memory regions.
+	 */
+	trans = ipa_cmd_trans_alloc(ipa, 4);
+	if (!trans) {
+		dev_err(&ipa->pdev->dev, "no transaction for memory setup\n");
+		return -EBUSY;
+	}
+
+	/* Initialize IPA-local header memory.  The modem and AP header
+	 * regions are contiguous, and initialized together.
+	 */
+	offset = ipa->mem[IPA_MEM_MODEM_HEADER].offset;
+	size = ipa->mem[IPA_MEM_MODEM_HEADER].size;
+	size += ipa->mem[IPA_MEM_AP_HEADER].size;
+
+	ipa_cmd_hdr_init_local_add(trans, offset, size, addr);
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM_PROC_CTX]);
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_AP_PROC_CTX]);
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM]);
+
+	gsi_trans_commit_wait(trans);
+
+	/* Tell the hardware where the processing context area is located */
+	iowrite32(ipa->mem_offset + offset,
+		  ipa->reg_virt + IPA_REG_LOCAL_PKT_PROC_CNTXT_BASE_OFFSET);
+
+	return 0;
+}
+
+void ipa_mem_teardown(struct ipa *ipa)
+{
+	/* Nothing to do */
+}
+
+#ifdef IPA_VALIDATE
+
+static bool ipa_mem_valid(struct ipa *ipa, enum ipa_mem_id mem_id)
+{
+	const struct ipa_mem *mem = &ipa->mem[mem_id];
+	struct device *dev = &ipa->pdev->dev;
+	u16 size_multiple;
+
+	/* Other than modem memory, sizes must be a multiple of 8 */
+	size_multiple = mem_id == IPA_MEM_MODEM ? 4 : 8;
+	if (mem->size % size_multiple)
+		dev_err(dev, "region %u size not a multiple of %u bytes\n",
+			mem_id, size_multiple);
+	else if (mem->offset % 8)
+		dev_err(dev, "region %u offset not 8-byte aligned\n", mem_id);
+	else if (mem->offset < mem->canary_count * sizeof(__le32))
+		dev_err(dev, "region %u offset too small for %hu canaries\n",
+			mem_id, mem->canary_count);
+	else if (mem->offset + mem->size > ipa->mem_size)
+		dev_err(dev, "region %u ends beyond memory limit (0x%08x)\n",
+			mem_id, ipa->mem_size);
+	else
+		return true;
+
+	return false;
+}
+
+#else /* !IPA_VALIDATE */
+
+static bool ipa_mem_valid(struct ipa *ipa, enum ipa_mem_id mem_id)
+{
+	return true;
+}
+
+#endif /*! IPA_VALIDATE */
+
+/**
+ * ipa_mem_config() - Configure IPA shared memory
+ *
+ * @Return:	0 if successful, or a negative error code
+ */
+int ipa_mem_config(struct ipa *ipa)
+{
+	struct device *dev = &ipa->pdev->dev;
+	enum ipa_mem_id mem_id;
+	dma_addr_t addr;
+	u32 mem_size;
+	void *virt;
+	u32 val;
+
+	/* Check the advertised location and size of the shared memory area */
+	val = ioread32(ipa->reg_virt + IPA_REG_SHARED_MEM_SIZE_OFFSET);
+
+	/* The fields in the register are in 8 byte units */
+	ipa->mem_offset = 8 * u32_get_bits(val, SHARED_MEM_BADDR_FMASK);
+	/* Make sure the end is within the region's mapped space */
+	mem_size = 8 * u32_get_bits(val, SHARED_MEM_SIZE_FMASK);
+
+	/* If the sizes don't match, issue a warning */
+	if (ipa->mem_offset + mem_size > ipa->mem_size) {
+		dev_warn(dev, "ignoring larger reported memory size: 0x%08x\n",
+			mem_size);
+	} else if (ipa->mem_offset + mem_size < ipa->mem_size) {
+		dev_warn(dev, "limiting IPA memory size to 0x%08x\n",
+			 mem_size);
+		ipa->mem_size = mem_size;
+	}
+
+	/* Prealloc DMA memory for zeroing regions */
+	virt = dma_alloc_coherent(dev, IPA_MEM_MAX, &addr, GFP_KERNEL);
+	if (!virt)
+		return -ENOMEM;
+	ipa->zero_addr = addr;
+	ipa->zero_virt = virt;
+	ipa->zero_size = IPA_MEM_MAX;
+
+	/* Verify each defined memory region is valid, and if indicated
+	 * for the region, write "canary" values in the space prior to
+	 * the region's base address.
+	 */
+	for (mem_id = 0; mem_id < IPA_MEM_COUNT; mem_id++) {
+		const struct ipa_mem *mem = &ipa->mem[mem_id];
+		u16 canary_count;
+		__le32 *canary;
+
+		/* Validate all regions (even undefined ones) */
+		if (!ipa_mem_valid(ipa, mem_id))
+			goto err_dma_free;
+
+		/* Skip over undefined regions */
+		if (!mem->offset && !mem->size)
+			continue;
+
+		canary_count = mem->canary_count;
+		if (!canary_count)
+			continue;
+
+		/* Write canary values in the space before the region */
+		canary = ipa->mem_virt + ipa->mem_offset + mem->offset;
+		do
+			*--canary = IPA_MEM_CANARY_VAL;
+		while (--canary_count);
+	}
+
+	/* Make sure filter and route table memory regions are valid */
+	if (!ipa_table_valid(ipa))
+		goto err_dma_free;
+
+	/* Validate memory-related properties relevant to immediate commands */
+	if (!ipa_cmd_data_valid(ipa))
+		goto err_dma_free;
+
+	/* Verify the microcontroller ring alignment (0 is OK too) */
+	if (ipa->mem[IPA_MEM_UC_EVENT_RING].offset % 1024) {
+		dev_err(dev, "microcontroller ring not 1024-byte aligned\n");
+		goto err_dma_free;
+	}
+
+	return 0;
+
+err_dma_free:
+	dma_free_coherent(dev, IPA_MEM_MAX, ipa->zero_virt, ipa->zero_addr);
+
+	return -EINVAL;
+}
+
+/* Inverse of ipa_mem_config() */
+void ipa_mem_deconfig(struct ipa *ipa)
+{
+	struct device *dev = &ipa->pdev->dev;
+
+	dma_free_coherent(dev, ipa->zero_size, ipa->zero_virt, ipa->zero_addr);
+	ipa->zero_size = 0;
+	ipa->zero_virt = NULL;
+	ipa->zero_addr = 0;
+}
+
+/**
+ * ipa_mem_zero_modem() - Zero IPA-local memory regions owned by the modem
+ *
+ * Zero regions of IPA-local memory used by the modem.  These are configured
+ * (and initially zeroed) by ipa_mem_setup(), but if the modem crashes and
+ * restarts via SSR we need to re-initialize them.  A QMI message tells the
+ * modem where to find regions of IPA local memory it needs to know about
+ * (these included).
+ */
+int ipa_mem_zero_modem(struct ipa *ipa)
+{
+	struct gsi_trans *trans;
+
+	/* Get a transaction to zero the modem memory, modem header,
+	 * and modem processing context regions.
+	 */
+	trans = ipa_cmd_trans_alloc(ipa, 3);
+	if (!trans) {
+		dev_err(&ipa->pdev->dev,
+			"no transaction to zero modem memory\n");
+		return -EBUSY;
+	}
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM_HEADER]);
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM_PROC_CTX]);
+
+	ipa_mem_zero_region_add(trans, &ipa->mem[IPA_MEM_MODEM]);
+
+	gsi_trans_commit_wait(trans);
+
+	return 0;
+}
+
+/* Perform memory region-related initialization */
+int ipa_mem_init(struct ipa *ipa, u32 count, const struct ipa_mem *mem)
+{
+	struct device *dev = &ipa->pdev->dev;
+	struct resource *res;
+	int ret;
+
+	if (count > IPA_MEM_COUNT) {
+		dev_err(dev, "to many memory regions (%u > %u)\n",
+			count, IPA_MEM_COUNT);
+		return -EINVAL;
+	}
+
+	ret = dma_set_mask_and_coherent(&ipa->pdev->dev, DMA_BIT_MASK(64));
+	if (ret) {
+		dev_err(dev, "error %d setting DMA mask\n", ret);
+		return ret;
+	}
+
+	res = platform_get_resource_byname(ipa->pdev, IORESOURCE_MEM,
+					   "ipa-shared");
+	if (!res) {
+		dev_err(dev,
+			"DT error getting \"ipa-shared\" memory property\n");
+		return -ENODEV;
+	}
+
+	ipa->mem_virt = memremap(res->start, resource_size(res), MEMREMAP_WC);
+	if (!ipa->mem_virt) {
+		dev_err(dev, "unable to remap \"ipa-shared\" memory\n");
+		return -ENOMEM;
+	}
+
+	ipa->mem_addr = res->start;
+	ipa->mem_size = resource_size(res);
+
+	/* The ipa->mem[] array is indexed by enum ipa_mem_id values */
+	ipa->mem = mem;
+
+	return 0;
+}
+
+/* Inverse of ipa_mem_init() */
+void ipa_mem_exit(struct ipa *ipa)
+{
+	memunmap(ipa->mem_virt);
+}
diff --git a/drivers/net/ipa/ipa_mem.h b/drivers/net/ipa/ipa_mem.h
new file mode 100644
index 000000000000..065cb499ebe5
--- /dev/null
+++ b/drivers/net/ipa/ipa_mem.h
@@ -0,0 +1,90 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2019-2020 Linaro Ltd.
+ */
+#ifndef _IPA_MEM_H_
+#define _IPA_MEM_H_
+
+struct ipa;
+
+/**
+ * DOC: IPA Local Memory
+ *
+ * The IPA has a block of shared memory, divided into regions used for
+ * specific purposes.
+ *
+ * The regions within the shared block are bounded by an offset (relative to
+ * the "ipa-shared" memory range) and size found in the IPA_SHARED_MEM_SIZE
+ * register.
+ *
+ * Each region is optionally preceded by one or more 32-bit "canary" values.
+ * These are meant to detect out-of-range writes (if they become corrupted).
+ * A given region (such as a filter or routing table) has the same number
+ * of canaries for all IPA hardware versions.  Still, the number used is
+ * defined in the config data, allowing for generic handling of regions.
+ *
+ * The set of memory regions is defined in configuration data.  They are
+ * subject to these constraints:
+ * - a zero offset and zero size represents and undefined region
+ * - a region's offset is defined to be *past* all "canary" values
+ * - offset must be large enough to account for all canaries
+ * - a region's size may be zero, but may still have canaries
+ * - all offsets must be 8-byte aligned
+ * - most sizes must be a multiple of 8
+ * - modem memory size must be a multiple of 4
+ * - the microcontroller ring offset must be a multiple of 1024
+ */
+
+/* The maximum allowed size for any memory region */
+#define IPA_MEM_MAX	(2 * PAGE_SIZE)
+
+/* IPA-resident memory region ids */
+enum ipa_mem_id {
+	IPA_MEM_UC_SHARED,		/* 0 canaries */
+	IPA_MEM_UC_INFO,		/* 0 canaries */
+	IPA_MEM_V4_FILTER_HASHED,	/* 2 canaries */
+	IPA_MEM_V4_FILTER,		/* 2 canaries */
+	IPA_MEM_V6_FILTER_HASHED,	/* 2 canaries */
+	IPA_MEM_V6_FILTER,		/* 2 canaries */
+	IPA_MEM_V4_ROUTE_HASHED,	/* 2 canaries */
+	IPA_MEM_V4_ROUTE,		/* 2 canaries */
+	IPA_MEM_V6_ROUTE_HASHED,	/* 2 canaries */
+	IPA_MEM_V6_ROUTE,		/* 2 canaries */
+	IPA_MEM_MODEM_HEADER,		/* 2 canaries */
+	IPA_MEM_AP_HEADER,		/* 0 canaries */
+	IPA_MEM_MODEM_PROC_CTX,		/* 2 canaries */
+	IPA_MEM_AP_PROC_CTX,		/* 0 canaries */
+	IPA_MEM_PDN_CONFIG,		/* 2 canaries (IPA v4.0 and above) */
+	IPA_MEM_STATS_QUOTA,		/* 2 canaries (IPA v4.0 and above) */
+	IPA_MEM_STATS_TETHERING,	/* 0 canaries (IPA v4.0 and above) */
+	IPA_MEM_STATS_DROP,		/* 0 canaries (IPA v4.0 and above) */
+	IPA_MEM_MODEM,			/* 0 canaries */
+	IPA_MEM_UC_EVENT_RING,		/* 1 canary */
+	IPA_MEM_COUNT,			/* Number of regions (not an index) */
+};
+
+/**
+ * struct ipa_mem - IPA local memory region description
+ * @offset:		offset in IPA memory space to base of the region
+ * @size:		size in bytes base of the region
+ * @canary_count	# 32-bit "canary" values that precede region
+ */
+struct ipa_mem {
+	u32 offset;
+	u16 size;
+	u16 canary_count;
+};
+
+int ipa_mem_config(struct ipa *ipa);
+void ipa_mem_deconfig(struct ipa *ipa);
+
+int ipa_mem_setup(struct ipa *ipa);
+void ipa_mem_teardown(struct ipa *ipa);
+
+int ipa_mem_zero_modem(struct ipa *ipa);
+
+int ipa_mem_init(struct ipa *ipa, u32 count, const struct ipa_mem *mem);
+void ipa_mem_exit(struct ipa *ipa);
+
+#endif /* _IPA_MEM_H_ */