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[v7,05/14] add minimal virtio support for devtree virtio-mmio

Message ID 1405500463-20713-6-git-send-email-drjones@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Andrew Jones July 16, 2014, 8:47 a.m. UTC 
Support the bare minimum of virtio to enable access to the virtio-mmio
config space of a device. Currently this implementation must use a
device tree to find the device.

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
---
v7:
 - s/alloc/calloc/
 - split into virtio.[ch] and virtio-mmio.[ch] [Paolo Bonzini]
 - dump virtio_bind_busses table [Paolo Bonzini]
v6:
 - switch to using alloc()
 - s/vmdev/vm_dev/ to be consistent with kernel naming
 - check for virtio magic in vm_dt_match
v5:
 - use same virtio struct names as kernel
 - no need to alloc a new virtio_config_ops for each virtio device
 - use ioremap
v4:
 - split from the virtio-testdev patch
 - search a table to "discover" that the device must be DT/virtio-mmio,
   which doesn't change anything, but looks less hacky than comments
   saying the device must be DT/virtio-mmio...
 - manage own pool of virtio-mmio pre-allocated device structures in
   order to avoid needing access to the heap
---
 lib/virtio-mmio.c | 111 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 lib/virtio-mmio.h |  47 +++++++++++++++++++++++
 lib/virtio.c      |  13 +++++++
 lib/virtio.h      |  74 ++++++++++++++++++++++++++++++++++++
 4 files changed, 245 insertions(+)
 create mode 100644 lib/virtio-mmio.c
 create mode 100644 lib/virtio-mmio.h
 create mode 100644 lib/virtio.c
 create mode 100644 lib/virtio.h
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Patch

diff --git a/lib/virtio-mmio.c b/lib/virtio-mmio.c
new file mode 100644
index 0000000000000..7331abf128cc5
--- /dev/null
+++ b/lib/virtio-mmio.c
@@ -0,0 +1,111 @@ 
+/*
+ * Copyright (C) 2014, Red Hat Inc, Andrew Jones <drjones@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ */
+#include "libcflat.h"
+#include "devicetree.h"
+#include "alloc.h"
+#include "asm/io.h"
+#include "virtio.h"
+#include "virtio-mmio.h"
+
+static void vm_get(struct virtio_device *vdev, unsigned offset,
+		   void *buf, unsigned len)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+	u8 *p = buf;
+	unsigned i;
+
+	for (i = 0; i < len; ++i)
+		p[i] = readb(vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
+}
+
+static void vm_set(struct virtio_device *vdev, unsigned offset,
+		   const void *buf, unsigned len)
+{
+	struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
+	const u8 *p = buf;
+	unsigned i;
+
+	for (i = 0; i < len; ++i)
+		writeb(p[i], vm_dev->base + VIRTIO_MMIO_CONFIG + offset + i);
+}
+
+static const struct virtio_config_ops vm_config_ops = {
+	.get = vm_get,
+	.set = vm_set,
+};
+
+static void vm_device_init(struct virtio_mmio_device *vm_dev)
+{
+	vm_dev->vdev.id.device = readl(vm_dev->base + VIRTIO_MMIO_DEVICE_ID);
+	vm_dev->vdev.id.vendor = readl(vm_dev->base + VIRTIO_MMIO_VENDOR_ID);
+	vm_dev->vdev.config = &vm_config_ops;
+}
+
+/******************************************************
+ * virtio-mmio device tree support
+ ******************************************************/
+
+struct vm_dt_info {
+	u32 devid;
+	void *base;
+};
+
+static int vm_dt_match(const struct dt_device *dev, int fdtnode)
+{
+	struct vm_dt_info *info = (struct vm_dt_info *)dev->info;
+	struct dt_pbus_reg base;
+	u32 magic;
+
+	dt_device_bind_node((struct dt_device *)dev, fdtnode);
+
+	assert(dt_pbus_get_base(dev, &base) == 0);
+	info->base = ioremap(base.addr, base.size);
+
+	magic = readl(info->base + VIRTIO_MMIO_MAGIC_VALUE);
+	if (magic != ('v' | 'i' << 8 | 'r' << 16 | 't' << 24))
+		return false;
+
+	return readl(info->base + VIRTIO_MMIO_DEVICE_ID) == info->devid;
+}
+
+static struct virtio_device *virtio_mmio_dt_bind(u32 devid)
+{
+	struct virtio_mmio_device *vm_dev;
+	struct dt_device dt_dev;
+	struct dt_bus dt_bus;
+	struct vm_dt_info info;
+	int node;
+
+	if (!dt_available())
+		return NULL;
+
+	dt_bus_init_defaults(&dt_bus);
+	dt_bus.match = vm_dt_match;
+
+	info.devid = devid;
+
+	dt_device_init(&dt_dev, &dt_bus, &info);
+
+	node = dt_device_find_compatible(&dt_dev, "virtio,mmio");
+	assert(node >= 0 || node == -FDT_ERR_NOTFOUND);
+
+	if (node == -FDT_ERR_NOTFOUND)
+		return NULL;
+
+	vm_dev = calloc(1, sizeof(*vm_dev));
+	if (!vm_dev)
+		return NULL;
+
+	vm_dev->base = info.base;
+	vm_device_init(vm_dev);
+
+	return &vm_dev->vdev;
+}
+
+struct virtio_device *virtio_mmio_bind(u32 devid)
+{
+	return virtio_mmio_dt_bind(devid);
+}
diff --git a/lib/virtio-mmio.h b/lib/virtio-mmio.h
new file mode 100644
index 0000000000000..7cd610428b486
--- /dev/null
+++ b/lib/virtio-mmio.h
@@ -0,0 +1,47 @@ 
+#ifndef _VIRTIO_MMIO_H_
+#define _VIRTIO_MMIO_H_
+/*
+ * A minimal implementation of virtio-mmio. Adapted from the Linux Kernel.
+ *
+ * Copyright (C) 2014, Red Hat Inc, Andrew Jones <drjones@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ */
+#include "libcflat.h"
+#include "virtio.h"
+
+#define VIRTIO_MMIO_MAGIC_VALUE		0x000
+#define VIRTIO_MMIO_VERSION		0x004
+#define VIRTIO_MMIO_DEVICE_ID		0x008
+#define VIRTIO_MMIO_VENDOR_ID		0x00c
+#define VIRTIO_MMIO_HOST_FEATURES	0x010
+#define VIRTIO_MMIO_HOST_FEATURES_SEL	0x014
+#define VIRTIO_MMIO_GUEST_FEATURES	0x020
+#define VIRTIO_MMIO_GUEST_FEATURES_SEL	0x024
+#define VIRTIO_MMIO_GUEST_PAGE_SIZE	0x028
+#define VIRTIO_MMIO_QUEUE_SEL		0x030
+#define VIRTIO_MMIO_QUEUE_NUM_MAX	0x034
+#define VIRTIO_MMIO_QUEUE_NUM		0x038
+#define VIRTIO_MMIO_QUEUE_ALIGN		0x03c
+#define VIRTIO_MMIO_QUEUE_PFN		0x040
+#define VIRTIO_MMIO_QUEUE_NOTIFY	0x050
+#define VIRTIO_MMIO_INTERRUPT_STATUS	0x060
+#define VIRTIO_MMIO_INTERRUPT_ACK	0x064
+#define VIRTIO_MMIO_STATUS		0x070
+#define VIRTIO_MMIO_CONFIG		0x100
+
+#define VIRTIO_MMIO_INT_VRING		(1 << 0)
+#define VIRTIO_MMIO_INT_CONFIG		(1 << 1)
+
+
+#define to_virtio_mmio_device(vdev_ptr) \
+	container_of(vdev_ptr, struct virtio_mmio_device, vdev)
+
+struct virtio_mmio_device {
+	struct virtio_device vdev;
+	void *base;
+};
+
+extern struct virtio_device *virtio_mmio_bind(u32 devid);
+
+#endif /* _VIRTIO_MMIO_H_ */
diff --git a/lib/virtio.c b/lib/virtio.c
new file mode 100644
index 0000000000000..b9c403cc71e05
--- /dev/null
+++ b/lib/virtio.c
@@ -0,0 +1,13 @@ 
+/*
+ * Copyright (C) 2014, Red Hat Inc, Andrew Jones <drjones@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ */
+#include "libcflat.h"
+#include "virtio.h"
+#include "virtio-mmio.h"
+
+struct virtio_device *virtio_bind(u32 devid)
+{
+	return virtio_mmio_bind(devid);
+}
diff --git a/lib/virtio.h b/lib/virtio.h
new file mode 100644
index 0000000000000..5941fa40a8655
--- /dev/null
+++ b/lib/virtio.h
@@ -0,0 +1,74 @@ 
+#ifndef _VIRTIO_H_
+#define _VIRTIO_H_
+/*
+ * A minimal implementation of virtio.
+ * Structures adapted from the Linux Kernel.
+ *
+ * Copyright (C) 2014, Red Hat Inc, Andrew Jones <drjones@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.
+ */
+#include "libcflat.h"
+
+struct virtio_device_id {
+	u32 device;
+	u32 vendor;
+};
+
+struct virtio_device {
+	struct virtio_device_id id;
+	const struct virtio_config_ops *config;
+};
+
+struct virtio_config_ops {
+	void (*get)(struct virtio_device *vdev, unsigned offset,
+		    void *buf, unsigned len);
+	void (*set)(struct virtio_device *vdev, unsigned offset,
+		    const void *buf, unsigned len);
+};
+
+static inline u8
+virtio_config_readb(struct virtio_device *vdev, unsigned offset)
+{
+	u8 val;
+	vdev->config->get(vdev, offset, &val, 1);
+	return val;
+}
+
+static inline u16
+virtio_config_readw(struct virtio_device *vdev, unsigned offset)
+{
+	u16 val;
+	vdev->config->get(vdev, offset, &val, 2);
+	return val;
+}
+
+static inline u32
+virtio_config_readl(struct virtio_device *vdev, unsigned offset)
+{
+	u32 val;
+	vdev->config->get(vdev, offset, &val, 4);
+	return val;
+}
+
+static inline void
+virtio_config_writeb(struct virtio_device *vdev, unsigned offset, u8 val)
+{
+	vdev->config->set(vdev, offset, &val, 1);
+}
+
+static inline void
+virtio_config_writew(struct virtio_device *vdev, unsigned offset, u16 val)
+{
+	vdev->config->set(vdev, offset, &val, 2);
+}
+
+static inline void
+virtio_config_writel(struct virtio_device *vdev, unsigned offset, u32 val)
+{
+	vdev->config->set(vdev, offset, &val, 4);
+}
+
+extern struct virtio_device *virtio_bind(u32 devid);
+
+#endif /* _VIRTIO_H_ */