drivers: ipm: added IPM over IVSHMEM driver

This driver is built on top of the IVSHMEM doorbell
notification mechanism providing an unified way
to generate inter VM interrupts.

Signed-off-by: Felipe Neves <felipe.neves@linaro.org>

CODEOWNERS

@@ -346,6 +346,7 @@
 /drivers/ipm/ipm_stm32_ipcc.c             @arnopo
 /drivers/ipm/ipm_stm32_hsem.c             @cameled
 /drivers/ipm/ipm_esp32.c                  @uLipe
+/drivers/ipm/ipm_ivshmem.c                @uLipe
 /drivers/kscan/                           @VenkatKotakonda @franciscomunoz @sjvasanth1
 /drivers/kscan/*xec*                      @franciscomunoz @sjvasanth1
 /drivers/kscan/*ft5336*                   @MaureenHelm

drivers/ipm/CMakeLists.txt

@@ -15,3 +15,4 @@ zephyr_library_sources_ifdef(CONFIG_IPM_STM32_HSEM ipm_stm32_hsem.c)
 zephyr_library_sources_ifdef(CONFIG_IPM_CAVS_HOST ipm_cavs_host.c)
 zephyr_library_sources_ifdef(CONFIG_ESP32_SOFT_IPM ipm_esp32.c)
 zephyr_library_sources_ifdef(CONFIG_USERSPACE   ipm_handlers.c)
+zephyr_library_sources_ifdef(CONFIG_IPM_IVSHMEM ipm_ivshmem.c)

drivers/ipm/Kconfig

@@ -38,10 +38,21 @@ config ESP32_SOFT_IPM
 	help
 	  Interprocessor driver for ESP32 when using AMP.
 
+config IPM_IVSHMEM
+	bool "IPM driver based on IVSHMEM-Doorbell"
+	default y
+	depends on DT_HAS_LINARO_IVSHMEM_IPM_ENABLED
+	depends on IVSHMEM
+	depends on IVSHMEM_DOORBELL
+	help
+	  Interprocessor driver using IVSHMEM Doorbell mechanism.
+
 source "drivers/ipm/Kconfig.nrfx"
 source "drivers/ipm/Kconfig.imx"
 source "drivers/ipm/Kconfig.stm32"
 source "drivers/ipm/Kconfig.intel_adsp"
+source "drivers/ipm/Kconfig.ivshmem"
+
 
 module = IPM
 module-str = ipm

drivers/ipm/Kconfig.ivshmem

@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: Apache-2.0
+# Copyright (c) 2023, Linaro
+
+if IPM_IVSHMEM
+
+config IPM_IVSHMEM_EVENT_LOOP_STACK_SIZE
+	int "Stack size in bytes of IVSHMEM IPM Event loop task"
+	default 8192
+	help
+	  Adjust the stack size, in bytes of the ivshmem event loop task.
+
+config IPM_IVSHMEM_EVENT_LOOP_PRIO
+	int "Priority of IVSHMEM IPM Event loop task"
+	default 2
+	help
+	  Adjust the priority of the ivshmem event loop task.
+
+endif

drivers/ipm/ipm_ivshmem.c

@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2023 Linaro.
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT linaro_ivshmem_ipm
+
+#include <stdint.h>
+#include <string.h>
+#include <zephyr/device.h>
+#include <zephyr/drivers/ipm.h>
+#include <zephyr/drivers/virtualization/ivshmem.h>
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(ipm_ivshmem, CONFIG_IPM_LOG_LEVEL);
+
+K_THREAD_STACK_DEFINE(ivshmem_ev_loop_stack, CONFIG_IPM_IVSHMEM_EVENT_LOOP_STACK_SIZE);
+static struct k_thread ivshmem_ev_loop_thread;
+
+struct ivshmem_ipm_data {
+	ipm_callback_t cb;
+	void *user_data;
+};
+
+struct ivshmem_ipm_config {
+	const struct device *ivshmem_dev;
+};
+
+static void ivshmem_ipm_event_loop_thread(void *arg, void *p2, void *p3)
+{
+	ARG_UNUSED(p2);
+	ARG_UNUSED(p3);
+
+	unsigned int poll_signaled;
+	int ivshmem_vector_rx;
+	struct k_poll_signal sig;
+	struct k_poll_event events[] = {
+		K_POLL_EVENT_INITIALIZER(K_POLL_TYPE_SIGNAL,
+					 K_POLL_MODE_NOTIFY_ONLY,
+					 &sig),
+	};
+
+	const struct device *dev = (const struct device *)arg;
+	struct ivshmem_ipm_data *dev_data = (struct ivshmem_ipm_data *)dev->data;
+	struct ivshmem_ipm_config *dev_cfg = (struct ivshmem_ipm_config *)dev->config;
+
+	k_poll_signal_init(&sig);
+	int ret = ivshmem_register_handler(dev_cfg->ivshmem_dev, &sig, 0);
+
+	if (ret < 0) {
+		LOG_ERR("registering handlers must be supported: %d\n", ret);
+		k_panic();
+	}
+
+	while (1) {
+		LOG_DBG("%s: waiting interrupt from client...\n", __func__);
+		ret = k_poll(events, ARRAY_SIZE(events), K_FOREVER);
+
+		k_poll_signal_check(&sig, &poll_signaled, &ivshmem_vector_rx);
+		/* get ready for next signal */
+		k_poll_signal_reset(&sig);
+
+		if (dev_data->cb)
+			dev_data->cb(dev, dev_data->user_data, 0, NULL);
+	}
+}
+
+static int ivshmem_ipm_send(const struct device *dev, int wait, uint32_t id,
+			 const void *data, int size)
+{
+	ARG_UNUSED(wait);
+	ARG_UNUSED(data);
+	ARG_UNUSED(size);
+
+	struct ivshmem_ipm_config *dev_cfg = (struct ivshmem_ipm_config *)dev->config;
+
+	LOG_DBG("sending notification to the peer id 0x%x\n", id);
+	return ivshmem_int_peer(dev_cfg->ivshmem_dev, id, 0);
+}
+
+static void ivshmem_ipm_register_callback(const struct device *dev,
+					ipm_callback_t cb,
+					void *user_data)
+{
+	struct ivshmem_ipm_data *dev_data = (struct ivshmem_ipm_data *)dev->data;
+
+	dev_data->cb = cb;
+	dev_data->user_data = user_data;
+}
+
+static int ivshmem_ipm_set_enabled(const struct device *dev, int enable)
+{
+	/* some subsystems needs this minimal function just return success here*/
+	ARG_UNUSED(dev);
+	ARG_UNUSED(enable);
+
+	return 0;
+}
+
+static int ivshmem_ipm_init(const struct device *dev)
+{
+	k_thread_create(&ivshmem_ev_loop_thread,
+		ivshmem_ev_loop_stack,
+		CONFIG_IPM_IVSHMEM_EVENT_LOOP_STACK_SIZE,
+		(k_thread_entry_t)ivshmem_ipm_event_loop_thread,
+		(void *)dev, NULL, NULL,
+		CONFIG_IPM_IVSHMEM_EVENT_LOOP_PRIO,
+		0, K_NO_WAIT);
+
+	return 0;
+}
+
+static const struct ipm_driver_api ivshmem_ipm_driver_api = {
+	.send = ivshmem_ipm_send,
+	.register_callback = ivshmem_ipm_register_callback,
+	.set_enabled = ivshmem_ipm_set_enabled
+};
+
+#define IPM_IVSHMEM_INIT(inst)								    \
+	static const struct ivshmem_ipm_config ivshmem_ipm_cfg_##inst = {	\
+		.ivshmem_dev =	\
+			DEVICE_DT_GET(DT_INST_PHANDLE(inst, ivshmem))\
+	};	\
+	static struct ivshmem_ipm_data ivshmem_ipm_data_##inst = {	\
+		.cb = NULL,	\
+		.user_data = NULL,	\
+	};	\
+	DEVICE_DT_INST_DEFINE(inst,	\
+				ivshmem_ipm_init,	\
+				NULL,	\
+				&ivshmem_ipm_data_##inst, &ivshmem_ipm_cfg_##inst,  \
+				POST_KERNEL, CONFIG_APPLICATION_INIT_PRIORITY,      \
+				&ivshmem_ipm_driver_api);                           \
+
+DT_INST_FOREACH_STATUS_OKAY(IPM_IVSHMEM_INIT);

dts/bindings/ipm/linaro,ivshmem-ipm.yaml

@@ -0,0 +1,15 @@
+# Copyright (c) 2023 Linaro
+# SPDX-License-Identifier: Apache-2.0
+
+description: Inter processor message based on IVSHMEM
+
+compatible: "linaro,ivshmem-ipm"
+
+include: base.yaml
+
+properties:
+
+  ivshmem:
+    type: phandle
+    required: true
+    description: ivshmem device node