Initial import

1 files changed, 398 insertions, 0 deletions

diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h
new file mode 100644
index 000000000..1e306f727
--- /dev/null
+++ b/include/linux/virtio_config.h
@@ -0,0 +1,398 @@
+#ifndef _LINUX_VIRTIO_CONFIG_H
+#define _LINUX_VIRTIO_CONFIG_H
+
+#include <linux/err.h>
+#include <linux/bug.h>
+#include <linux/virtio.h>
+#include <linux/virtio_byteorder.h>
+#include <uapi/linux/virtio_config.h>
+
+/**
+ * virtio_config_ops - operations for configuring a virtio device
+ * @get: read the value of a configuration field
+ *	vdev: the virtio_device
+ *	offset: the offset of the configuration field
+ *	buf: the buffer to write the field value into.
+ *	len: the length of the buffer
+ * @set: write the value of a configuration field
+ *	vdev: the virtio_device
+ *	offset: the offset of the configuration field
+ *	buf: the buffer to read the field value from.
+ *	len: the length of the buffer
+ * @generation: config generation counter
+ *	vdev: the virtio_device
+ *	Returns the config generation counter
+ * @get_status: read the status byte
+ *	vdev: the virtio_device
+ *	Returns the status byte
+ * @set_status: write the status byte
+ *	vdev: the virtio_device
+ *	status: the new status byte
+ * @reset: reset the device
+ *	vdev: the virtio device
+ *	After this, status and feature negotiation must be done again
+ *	Device must not be reset from its vq/config callbacks, or in
+ *	parallel with being added/removed.
+ * @find_vqs: find virtqueues and instantiate them.
+ *	vdev: the virtio_device
+ *	nvqs: the number of virtqueues to find
+ *	vqs: on success, includes new virtqueues
+ *	callbacks: array of callbacks, for each virtqueue
+ *		include a NULL entry for vqs that do not need a callback
+ *	names: array of virtqueue names (mainly for debugging)
+ *		include a NULL entry for vqs unused by driver
+ *	Returns 0 on success or error status
+ * @del_vqs: free virtqueues found by find_vqs().
+ * @get_features: get the array of feature bits for this device.
+ *	vdev: the virtio_device
+ *	Returns the first 32 feature bits (all we currently need).
+ * @finalize_features: confirm what device features we'll be using.
+ *	vdev: the virtio_device
+ *	This gives the final feature bits for the device: it can change
+ *	the dev->feature bits if it wants.
+ *	Returns 0 on success or error status
+ * @bus_name: return the bus name associated with the device
+ *	vdev: the virtio_device
+ *      This returns a pointer to the bus name a la pci_name from which
+ *      the caller can then copy.
+ * @set_vq_affinity: set the affinity for a virtqueue.
+ */
+typedef void vq_callback_t(struct virtqueue *);
+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);
+	u32 (*generation)(struct virtio_device *vdev);
+	u8 (*get_status)(struct virtio_device *vdev);
+	void (*set_status)(struct virtio_device *vdev, u8 status);
+	void (*reset)(struct virtio_device *vdev);
+	int (*find_vqs)(struct virtio_device *, unsigned nvqs,
+			struct virtqueue *vqs[],
+			vq_callback_t *callbacks[],
+			const char *names[]);
+	void (*del_vqs)(struct virtio_device *);
+	u64 (*get_features)(struct virtio_device *vdev);
+	int (*finalize_features)(struct virtio_device *vdev);
+	const char *(*bus_name)(struct virtio_device *vdev);
+	int (*set_vq_affinity)(struct virtqueue *vq, int cpu);
+};
+
+/* If driver didn't advertise the feature, it will never appear. */
+void virtio_check_driver_offered_feature(const struct virtio_device *vdev,
+					 unsigned int fbit);
+
+/**
+ * __virtio_test_bit - helper to test feature bits. For use by transports.
+ *                     Devices should normally use virtio_has_feature,
+ *                     which includes more checks.
+ * @vdev: the device
+ * @fbit: the feature bit
+ */
+static inline bool __virtio_test_bit(const struct virtio_device *vdev,
+				     unsigned int fbit)
+{
+	/* Did you forget to fix assumptions on max features? */
+	if (__builtin_constant_p(fbit))
+		BUILD_BUG_ON(fbit >= 64);
+	else
+		BUG_ON(fbit >= 64);
+
+	return vdev->features & BIT_ULL(fbit);
+}
+
+/**
+ * __virtio_set_bit - helper to set feature bits. For use by transports.
+ * @vdev: the device
+ * @fbit: the feature bit
+ */
+static inline void __virtio_set_bit(struct virtio_device *vdev,
+				    unsigned int fbit)
+{
+	/* Did you forget to fix assumptions on max features? */
+	if (__builtin_constant_p(fbit))
+		BUILD_BUG_ON(fbit >= 64);
+	else
+		BUG_ON(fbit >= 64);
+
+	vdev->features |= BIT_ULL(fbit);
+}
+
+/**
+ * __virtio_clear_bit - helper to clear feature bits. For use by transports.
+ * @vdev: the device
+ * @fbit: the feature bit
+ */
+static inline void __virtio_clear_bit(struct virtio_device *vdev,
+				      unsigned int fbit)
+{
+	/* Did you forget to fix assumptions on max features? */
+	if (__builtin_constant_p(fbit))
+		BUILD_BUG_ON(fbit >= 64);
+	else
+		BUG_ON(fbit >= 64);
+
+	vdev->features &= ~BIT_ULL(fbit);
+}
+
+/**
+ * virtio_has_feature - helper to determine if this device has this feature.
+ * @vdev: the device
+ * @fbit: the feature bit
+ */
+static inline bool virtio_has_feature(const struct virtio_device *vdev,
+				      unsigned int fbit)
+{
+	if (fbit < VIRTIO_TRANSPORT_F_START)
+		virtio_check_driver_offered_feature(vdev, fbit);
+
+	return __virtio_test_bit(vdev, fbit);
+}
+
+static inline
+struct virtqueue *virtio_find_single_vq(struct virtio_device *vdev,
+					vq_callback_t *c, const char *n)
+{
+	vq_callback_t *callbacks[] = { c };
+	const char *names[] = { n };
+	struct virtqueue *vq;
+	int err = vdev->config->find_vqs(vdev, 1, &vq, callbacks, names);
+	if (err < 0)
+		return ERR_PTR(err);
+	return vq;
+}
+
+/**
+ * virtio_device_ready - enable vq use in probe function
+ * @vdev: the device
+ *
+ * Driver must call this to use vqs in the probe function.
+ *
+ * Note: vqs are enabled automatically after probe returns.
+ */
+static inline
+void virtio_device_ready(struct virtio_device *dev)
+{
+	unsigned status = dev->config->get_status(dev);
+
+	BUG_ON(status & VIRTIO_CONFIG_S_DRIVER_OK);
+	dev->config->set_status(dev, status | VIRTIO_CONFIG_S_DRIVER_OK);
+}
+
+static inline
+const char *virtio_bus_name(struct virtio_device *vdev)
+{
+	if (!vdev->config->bus_name)
+		return "virtio";
+	return vdev->config->bus_name(vdev);
+}
+
+/**
+ * virtqueue_set_affinity - setting affinity for a virtqueue
+ * @vq: the virtqueue
+ * @cpu: the cpu no.
+ *
+ * Pay attention the function are best-effort: the affinity hint may not be set
+ * due to config support, irq type and sharing.
+ *
+ */
+static inline
+int virtqueue_set_affinity(struct virtqueue *vq, int cpu)
+{
+	struct virtio_device *vdev = vq->vdev;
+	if (vdev->config->set_vq_affinity)
+		return vdev->config->set_vq_affinity(vq, cpu);
+	return 0;
+}
+
+/* Memory accessors */
+static inline u16 virtio16_to_cpu(struct virtio_device *vdev, __virtio16 val)
+{
+	return __virtio16_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio16 cpu_to_virtio16(struct virtio_device *vdev, u16 val)
+{
+	return __cpu_to_virtio16(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+static inline u32 virtio32_to_cpu(struct virtio_device *vdev, __virtio32 val)
+{
+	return __virtio32_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio32 cpu_to_virtio32(struct virtio_device *vdev, u32 val)
+{
+	return __cpu_to_virtio32(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+static inline u64 virtio64_to_cpu(struct virtio_device *vdev, __virtio64 val)
+{
+	return __virtio64_to_cpu(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+static inline __virtio64 cpu_to_virtio64(struct virtio_device *vdev, u64 val)
+{
+	return __cpu_to_virtio64(virtio_has_feature(vdev, VIRTIO_F_VERSION_1), val);
+}
+
+/* Config space accessors. */
+#define virtio_cread(vdev, structname, member, ptr)			\
+	do {								\
+		/* Must match the member's type, and be integer */	\
+		if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
+			(*ptr) = 1;					\
+									\
+		switch (sizeof(*ptr)) {					\
+		case 1:							\
+			*(ptr) = virtio_cread8(vdev,			\
+					       offsetof(structname, member)); \
+			break;						\
+		case 2:							\
+			*(ptr) = virtio_cread16(vdev,			\
+						offsetof(structname, member)); \
+			break;						\
+		case 4:							\
+			*(ptr) = virtio_cread32(vdev,			\
+						offsetof(structname, member)); \
+			break;						\
+		case 8:							\
+			*(ptr) = virtio_cread64(vdev,			\
+						offsetof(structname, member)); \
+			break;						\
+		default:						\
+			BUG();						\
+		}							\
+	} while(0)
+
+/* Config space accessors. */
+#define virtio_cwrite(vdev, structname, member, ptr)			\
+	do {								\
+		/* Must match the member's type, and be integer */	\
+		if (!typecheck(typeof((((structname*)0)->member)), *(ptr))) \
+			BUG_ON((*ptr) == 1);				\
+									\
+		switch (sizeof(*ptr)) {					\
+		case 1:							\
+			virtio_cwrite8(vdev,				\
+				       offsetof(structname, member),	\
+				       *(ptr));				\
+			break;						\
+		case 2:							\
+			virtio_cwrite16(vdev,				\
+					offsetof(structname, member),	\
+					*(ptr));			\
+			break;						\
+		case 4:							\
+			virtio_cwrite32(vdev,				\
+					offsetof(structname, member),	\
+					*(ptr));			\
+			break;						\
+		case 8:							\
+			virtio_cwrite64(vdev,				\
+					offsetof(structname, member),	\
+					*(ptr));			\
+			break;						\
+		default:						\
+			BUG();						\
+		}							\
+	} while(0)
+
+/* Read @count fields, @bytes each. */
+static inline void __virtio_cread_many(struct virtio_device *vdev,
+				       unsigned int offset,
+				       void *buf, size_t count, size_t bytes)
+{
+	u32 old, gen = vdev->config->generation ?
+		vdev->config->generation(vdev) : 0;
+	int i;
+
+	do {
+		old = gen;
+
+		for (i = 0; i < count; i++)
+			vdev->config->get(vdev, offset + bytes * i,
+					  buf + i * bytes, bytes);
+
+		gen = vdev->config->generation ?
+			vdev->config->generation(vdev) : 0;
+	} while (gen != old);
+}
+
+static inline void virtio_cread_bytes(struct virtio_device *vdev,
+				      unsigned int offset,
+				      void *buf, size_t len)
+{
+	__virtio_cread_many(vdev, offset, buf, len, 1);
+}
+
+static inline u8 virtio_cread8(struct virtio_device *vdev, unsigned int offset)
+{
+	u8 ret;
+	vdev->config->get(vdev, offset, &ret, sizeof(ret));
+	return ret;
+}
+
+static inline void virtio_cwrite8(struct virtio_device *vdev,
+				  unsigned int offset, u8 val)
+{
+	vdev->config->set(vdev, offset, &val, sizeof(val));
+}
+
+static inline u16 virtio_cread16(struct virtio_device *vdev,
+				 unsigned int offset)
+{
+	u16 ret;
+	vdev->config->get(vdev, offset, &ret, sizeof(ret));
+	return virtio16_to_cpu(vdev, (__force __virtio16)ret);
+}
+
+static inline void virtio_cwrite16(struct virtio_device *vdev,
+				   unsigned int offset, u16 val)
+{
+	val = (__force u16)cpu_to_virtio16(vdev, val);
+	vdev->config->set(vdev, offset, &val, sizeof(val));
+}
+
+static inline u32 virtio_cread32(struct virtio_device *vdev,
+				 unsigned int offset)
+{
+	u32 ret;
+	vdev->config->get(vdev, offset, &ret, sizeof(ret));
+	return virtio32_to_cpu(vdev, (__force __virtio32)ret);
+}
+
+static inline void virtio_cwrite32(struct virtio_device *vdev,
+				   unsigned int offset, u32 val)
+{
+	val = (__force u32)cpu_to_virtio32(vdev, val);
+	vdev->config->set(vdev, offset, &val, sizeof(val));
+}
+
+static inline u64 virtio_cread64(struct virtio_device *vdev,
+				 unsigned int offset)
+{
+	u64 ret;
+	__virtio_cread_many(vdev, offset, &ret, 1, sizeof(ret));
+	return virtio64_to_cpu(vdev, (__force __virtio64)ret);
+}
+
+static inline void virtio_cwrite64(struct virtio_device *vdev,
+				   unsigned int offset, u64 val)
+{
+	val = (__force u64)cpu_to_virtio64(vdev, val);
+	vdev->config->set(vdev, offset, &val, sizeof(val));
+}
+
+/* Conditional config space accessors. */
+#define virtio_cread_feature(vdev, fbit, structname, member, ptr)	\
+	({								\
+		int _r = 0;						\
+		if (!virtio_has_feature(vdev, fbit))			\
+			_r = -ENOENT;					\
+		else							\
+			virtio_cread((vdev), structname, member, ptr);	\
+		_r;							\
+	})
+
+#endif /* _LINUX_VIRTIO_CONFIG_H */