virtio: virtio-mmio framework

VIRTIO MMIO transport for OpenAMP.

Signed-off-by: Dan Milea <dan.milea@windriver.com>

cmake/options.cmake

@@ -78,6 +78,12 @@ if (NOT WITH_VIRTIO_DEVICE AND NOT WITH_VIRTIO_SLAVE)
 	add_definitions(-DVIRTIO_DRIVER_ONLY)
 endif (NOT WITH_VIRTIO_DEVICE AND NOT WITH_VIRTIO_SLAVE)
 
+option (WITH_VIRTIO_MMIO_DRV "Build with virtio mmio driver support enabled" OFF)
+
+if (WITH_VIRTIO_MMIO_DRV)
+  add_definitions(-DWITH_VIRTIO_MMIO_DRV)
+endif (WITH_VIRTIO_MMIO_DRV)
+
 option (WITH_DCACHE_VRINGS "Build with vrings cache operations enabled" OFF)
 
 if (WITH_DCACHE_VRINGS)

lib/CMakeLists.txt

@@ -10,6 +10,9 @@ collect (PROJECT_LIB_SOURCES version.c)
 add_subdirectory (virtio)
 add_subdirectory (rpmsg)
 add_subdirectory (remoteproc)
+if (WITH_VIRTIO_MMIO_DRV)
+add_subdirectory (virtio_mmio)
+endif (WITH_VIRTIO_MMIO_DRV)
 
 if (WITH_PROXY)
   add_subdirectory (proxy)

lib/include/openamp/rpmsg_virtio.h

@@ -142,7 +142,7 @@ rpmsg_virtio_create_virtqueues(struct rpmsg_virtio_device *rvdev,
 			       vq_callback *callbacks)
 {
 	return virtio_create_virtqueues(rvdev->vdev, flags, nvqs, names,
-					callbacks);
+					callbacks, NULL);
 }
 
 /**

lib/include/openamp/virtio.h

@@ -98,6 +98,7 @@ __deprecated static inline int deprecated_virtio_dev_slave(void)
 struct virtio_device_id {
 	uint32_t device;
 	uint32_t vendor;
+	uint32_t version;
 };
 
 /*
@@ -120,6 +121,44 @@ struct virtio_device_id {
 #define VIRTIO_TRANSPORT_F_START      28
 #define VIRTIO_TRANSPORT_F_END        32
 
+#ifdef VIRTIO_DEBUG
+#include <metal/log.h>
+
+#define VIRTIO_ASSERT(_exp, _msg) do { \
+		if (!(_exp)) { \
+			metal_log(METAL_LOG_EMERGENCY, \
+				  "FATAL: %s - " _msg, __func__); \
+			metal_assert(_exp); \
+		} \
+	} while (0)
+#else
+#define VIRTIO_ASSERT(_exp, _msg) metal_assert(_exp)
+#endif /* VIRTIO_DEBUG */
+
+#define VRING_ALIGNMENT           4096
+
+#define VIRTIO_RING_SIZE(n, align) \
+	(( \
+		( \
+		sizeof(struct vring_desc) * n + \
+		sizeof(struct vring_avail) + \
+		sizeof(uint16_t) * (n + 1) + \
+		align - 1 \
+		) \
+		& ~(align - 1) \
+	) + \
+	sizeof(struct vring_used) + \
+	sizeof(struct vring_used_elem) * n + sizeof(uint16_t))
+
+#define VRING_DECLARE(name, n, align) \
+static char __vrbuf_##name[VIRTIO_RING_SIZE(n, align)] __aligned(VRING_ALIGNMENT); \
+static struct vring __vring_##name = { \
+	.desc = (void *)__vrbuf_##name, \
+	.avail = (void *)((unsigned long)__vrbuf_##name + n * sizeof(struct vring_desc)), \
+	.used = (void *)((unsigned long)__vrbuf_##name + ((n * sizeof(struct vring_desc) + \
+		(n + 1) * sizeof(uint16_t) + align - 1) & ~(align - 1))), \
+}
+
 typedef void (*virtio_dev_reset_cb)(struct virtio_device *vdev);
 
 struct virtio_dispatch;
@@ -180,7 +219,8 @@ struct virtio_dispatch {
 	int (*create_virtqueues)(struct virtio_device *vdev,
 				 unsigned int flags,
 				 unsigned int nvqs, const char *names[],
-				 vq_callback callbacks[]);
+				 vq_callback callbacks[],
+				 void *callback_args[]);
 	void (*delete_virtqueues)(struct virtio_device *vdev);
 	uint8_t (*get_status)(struct virtio_device *dev);
 	void (*set_status)(struct virtio_device *dev, uint8_t status);
@@ -205,17 +245,18 @@ struct virtio_dispatch {
 /**
  * @brief Create the virtio device virtqueue.
  *
- * @param vdev		Pointer to virtio device structure.
- * @param flags		Create flag.
- * @param nvqs		The virtqueue number.
- * @param names		Virtqueue names.
- * @param callbacks	Virtqueue callback functions.
+ * @param vdev			Pointer to virtio device structure.
+ * @param flags			Create flag.
+ * @param nvqs			The virtqueue number.
+ * @param names			Virtqueue names.
+ * @param callbacks		Virtqueue callback functions.
+ * @param callback_args	Virtqueue callback function arguments.
  *
  * @return 0 on success, otherwise error code.
  */
 int virtio_create_virtqueues(struct virtio_device *vdev, unsigned int flags,
 			     unsigned int nvqs, const char *names[],
-			     vq_callback callbacks[]);
+			     vq_callback callbacks[], void *callback_args[]);
 
 /**
  * @brief Delete the virtio device virtqueue.
@@ -236,6 +277,20 @@ static inline int virtio_delete_virtqueues(struct virtio_device *vdev)
 	return 0;
 }
 
+/**
+ * @brief Get device ID.
+ *
+ * @param dev Pointer to device structure.
+ *
+ * @return Device ID value.
+ */
+static inline uint32_t virtio_get_devid(const struct virtio_device *vdev)
+{
+	if (!vdev)
+		return 0;
+	return vdev->id.device;
+}
+
 /**
  * @brief Retrieve device status.
  *

lib/include/openamp/virtio_mmio.h

@@ -0,0 +1,216 @@
+/*
+ * Copyright (c) 2022 Wind River Systems, Inc.
+ * Based on Virtio PCI driver by Anthony Liguori, copyright IBM Corp. 2007
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef OPENAMP_VIRTIO_MMIO_H
+#define OPENAMP_VIRTIO_MMIO_H
+
+#include <metal/device.h>
+#include <openamp/virtio.h>
+#include <openamp/virtqueue.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Enable support for legacy devices */
+#define VIRTIO_MMIO_LEGACY
+
+/* Control registers */
+
+/* Magic value ("virt" string) - Read Only */
+#define VIRTIO_MMIO_MAGIC_VALUE		0x000
+
+#define VIRTIO_MMIO_MAGIC_VALUE_STRING ('v' | ('i' << 8) | ('r' << 16) | ('t' << 24))
+
+/* Virtio device version - Read Only */
+#define VIRTIO_MMIO_VERSION		0x004
+
+/* Virtio device ID - Read Only */
+#define VIRTIO_MMIO_DEVICE_ID		0x008
+
+/* Virtio vendor ID - Read Only */
+#define VIRTIO_MMIO_VENDOR_ID		0x00c
+
+/*
+ * Bitmask of the features supported by the device (host)
+ * (32 bits per set) - Read Only
+ */
+#define VIRTIO_MMIO_DEVICE_FEATURES	0x010
+
+/* Device (host) features set selector - Write Only */
+#define VIRTIO_MMIO_DEVICE_FEATURES_SEL	0x014
+
+/*
+ * Bitmask of features activated by the driver (guest)
+ * (32 bits per set) - Write Only
+ */
+#define VIRTIO_MMIO_DRIVER_FEATURES	0x020
+
+/* Activated features set selector - Write Only */
+#define VIRTIO_MMIO_DRIVER_FEATURES_SEL	0x024
+
+#ifndef VIRTIO_MMIO_NO_LEGACY /* LEGACY DEVICES ONLY! */
+/* Guest's memory page size in bytes - Write Only */
+#define VIRTIO_MMIO_GUEST_PAGE_SIZE	0x028
+#endif
+
+/* Queue selector - Write Only */
+#define VIRTIO_MMIO_QUEUE_SEL		0x030
+
+/* Maximum size of the currently selected queue - Read Only */
+#define VIRTIO_MMIO_QUEUE_NUM_MAX	0x034
+
+/* Queue size for the currently selected queue - Write Only */
+#define VIRTIO_MMIO_QUEUE_NUM		0x038
+
+#ifdef VIRTIO_MMIO_LEGACY
+/* Used Ring alignment for the currently selected queue - Write Only */
+#define VIRTIO_MMIO_QUEUE_ALIGN		0x03c
+/* Guest's PFN for the currently selected queue - Read Write */
+#define VIRTIO_MMIO_QUEUE_PFN		0x040
+#endif
+
+/* Ready bit for the currently selected queue - Read Write */
+#define VIRTIO_MMIO_QUEUE_READY		0x044
+
+/* Queue notifier - Write Only */
+#define VIRTIO_MMIO_QUEUE_NOTIFY	0x050
+
+/* Interrupt status - Read Only */
+#define VIRTIO_MMIO_INTERRUPT_STATUS	0x060
+
+/* Interrupt acknowledge - Write Only */
+#define VIRTIO_MMIO_INTERRUPT_ACK	0x064
+
+/* Device status register - Read Write */
+#define VIRTIO_MMIO_STATUS		0x070
+
+/* Selected queue's Descriptor Table address, 64 bits in two halves */
+#define VIRTIO_MMIO_QUEUE_DESC_LOW	0x080
+#define VIRTIO_MMIO_QUEUE_DESC_HIGH	0x084
+
+/* Selected queue's Available Ring address, 64 bits in two halves */
+#define VIRTIO_MMIO_QUEUE_AVAIL_LOW	0x090
+#define VIRTIO_MMIO_QUEUE_AVAIL_HIGH	0x094
+
+/* Selected queue's Used Ring address, 64 bits in two halves */
+#define VIRTIO_MMIO_QUEUE_USED_LOW	0x0a0
+#define VIRTIO_MMIO_QUEUE_USED_HIGH	0x0a4
+
+/* Shared memory region id */
+#define VIRTIO_MMIO_SHM_SEL             0x0ac
+
+/* Shared memory region length, 64 bits in two halves */
+#define VIRTIO_MMIO_SHM_LEN_LOW         0x0b0
+#define VIRTIO_MMIO_SHM_LEN_HIGH        0x0b4
+
+/* Shared memory region base address, 64 bits in two halves */
+#define VIRTIO_MMIO_SHM_BASE_LOW        0x0b8
+#define VIRTIO_MMIO_SHM_BASE_HIGH       0x0bc
+
+/* Configuration atomicity value */
+#define VIRTIO_MMIO_CONFIG_GENERATION	0x0fc
+
+/*
+ * The config space is defined by each driver as
+ * the per-driver configuration space - Read Write
+ */
+#define VIRTIO_MMIO_CONFIG		0x100
+
+/* Interrupt flags (re: interrupt status & acknowledge registers) */
+#define VIRTIO_MMIO_INT_VRING		(1 << 0)
+#define VIRTIO_MMIO_INT_CONFIG		(1 << 1)
+
+/* Data buffer size for preallocated buffers before vring */
+#define VIRTIO_MMIO_MAX_DATA_SIZE 128
+
+/**
+ * struct virtio_mmio_dev_mem: VIRTIO MMIO memory area
+ * @base memory region physical address
+ * @size memory region size
+ */
+struct virtio_mmio_dev_mem {
+	void *base;
+	size_t size;
+};
+
+/**
+ * struct virtio_mmio_device: representation of a VIRTIO MMIO device
+ * @vdev	base virtio device struct
+ * @cfg_io	device configuration space metal_io_region
+ * @shm_io	pre-shared memory space metal_io_region
+ * @shm_device	shared memory device
+ * @cfg_mem	VIRTIO device configuration space
+ * @shm_mem	VIRTIO device pre-shared memory
+ * @device_mode	VIRTIO_DEV_DRIVER or VIRTIO_DEV_DEVICE
+ * @irq		interrupt number
+ * @user_data	custom user data
+ */
+struct virtio_mmio_device {
+	struct virtio_device vdev;
+	struct metal_io_region *cfg_io;
+	struct metal_io_region *shm_io;
+	struct metal_device shm_device;
+	struct virtio_mmio_dev_mem cfg_mem;
+	struct virtio_mmio_dev_mem shm_mem;
+	unsigned int device_mode;
+	unsigned int irq;
+	void *user_data;
+};
+
+/**
+ * @brief Register a VIRTIO device with the VIRTIO stack.
+ *
+ * @param dev		Pointer to device structure.
+ * @param vq_num	Number of virtqueues the device uses.
+ * @param vqs		Array of pointers to vthe virtqueues used by the device.
+ */
+void virtio_mmio_register_device(struct virtio_device *vdev, int vq_num, struct virtqueue **vqs);
+
+/**
+ * @brief Setup a virtqueue structure.
+ *
+ * @param dev		Pointer to device structure.
+ * @param idx		Index of the virtqueue.
+ * @param vq		Pointer to virtqueue structure.
+ * @param cb		Pointer to virtqueue callback. Can be NULL.
+ * @param cb_arg	Argument for the virtqueue callback.
+ *
+ * @return pointer to virtqueue structure.
+ */
+struct virtqueue *virtio_mmio_setup_virtqueue(struct virtio_device *vdev,
+					      unsigned int idx,
+					      struct virtqueue *vq,
+					      void (*cb)(void *),
+					      void *cb_arg,
+					      const char *vq_name);
+
+/**
+ * @brief VIRTIO MMIO device initialization.
+ *
+ * @param vmdev			Pointer to virtio_mmio_device structure.
+ * @param virt_mem_ptr	Guest virtio (shared) memory base address (virtual).
+ * @param cfg_mem_ptr	Virtio device configuration memory base address (virtual).
+ * @param user_data		Pointer to custom user data.
+ *
+ * @return int 0 for success.
+ */
+int virtio_mmio_device_init(struct virtio_mmio_device *vmdev, uintptr_t virt_mem_ptr,
+			    uintptr_t cfg_mem_ptr, void *user_data);
+
+/**
+ * @brief VIRTIO MMIO interrupt service routine.
+ *
+ * @param vdev Pointer to virtio_device structure.
+ */
+void virtio_mmio_isr(struct virtio_device *vdev);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* OPENAMP_VIRTIO_MMIO_H */

lib/include/openamp/virtqueue.h

@@ -63,6 +63,7 @@ struct virtqueue {
 	uint16_t vq_queue_index;
 	uint16_t vq_nentries;
 	void (*callback)(struct virtqueue *vq);
+	void *priv;
 	void (*notify)(struct virtqueue *vq);
 	struct vring vq_ring;
 	uint16_t vq_free_cnt;
@@ -334,6 +335,30 @@ uint32_t virtqueue_get_desc_size(struct virtqueue *vq);
 uint32_t virtqueue_get_buffer_length(struct virtqueue *vq, uint16_t idx);
 void *virtqueue_get_buffer_addr(struct virtqueue *vq, uint16_t idx);
 
+/**
+ * @brief Test if virtqueue is empty
+ *
+ * @param vq	Pointer to VirtIO queue control block
+ *
+ * @return 1 if virtqueue is empty
+ */
+static inline int virtqueue_empty(struct virtqueue *vq)
+{
+	return (vq->vq_nentries == vq->vq_free_cnt);
+}
+
+/**
+ * @brief Test if virtqueue is full
+ *
+ * @param vq	Pointer to VirtIO queue control block
+ *
+ * @return 1 if virtqueue is full
+ */
+static inline int virtqueue_full(struct virtqueue *vq)
+{
+	return (vq->vq_free_cnt == 0);
+}
+
 #if defined __cplusplus
 }
 #endif