1 files changed, 297 insertions, 0 deletions
diff --git a/drivers/hid/intel-ish-hid/ishtp/client-buffers.c b/drivers/hid/intel-ish-hid/ishtp/client-buffers.c
new file mode 100644
index 000000000..513d7a4a1
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ishtp/client-buffers.c
@@ -0,0 +1,297 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ISHTP Ring Buffers
+ *
+ * Copyright (c) 2003-2016, Intel Corporation.
+ */
+
+#include <linux/slab.h>
+#include "client.h"
+
+/**
+ * ishtp_cl_alloc_rx_ring() - Allocate RX ring buffers
+ * @cl: client device instance
+ *
+ * Allocate and initialize RX ring buffers
+ *
+ * Return: 0 on success else -ENOMEM
+ */
+int ishtp_cl_alloc_rx_ring(struct ishtp_cl *cl)
+{
+	size_t	len = cl->device->fw_client->props.max_msg_length;
+	int	j;
+	struct ishtp_cl_rb *rb;
+	int	ret = 0;
+	unsigned long	flags;
+
+	for (j = 0; j < cl->rx_ring_size; ++j) {
+		rb = ishtp_io_rb_init(cl);
+		if (!rb) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		ret = ishtp_io_rb_alloc_buf(rb, len);
+		if (ret)
+			goto out;
+		spin_lock_irqsave(&cl->free_list_spinlock, flags);
+		list_add_tail(&rb->list, &cl->free_rb_list.list);
+		spin_unlock_irqrestore(&cl->free_list_spinlock, flags);
+	}
+
+	return	0;
+
+out:
+	dev_err(&cl->device->dev, "error in allocating Rx buffers\n");
+	ishtp_cl_free_rx_ring(cl);
+	return	ret;
+}
+
+/**
+ * ishtp_cl_alloc_tx_ring() - Allocate TX ring buffers
+ * @cl: client device instance
+ *
+ * Allocate and initialize TX ring buffers
+ *
+ * Return: 0 on success else -ENOMEM
+ */
+int ishtp_cl_alloc_tx_ring(struct ishtp_cl *cl)
+{
+	size_t	len = cl->device->fw_client->props.max_msg_length;
+	int	j;
+	unsigned long	flags;
+
+	cl->tx_ring_free_size = 0;
+
+	/* Allocate pool to free Tx bufs */
+	for (j = 0; j < cl->tx_ring_size; ++j) {
+		struct ishtp_cl_tx_ring	*tx_buf;
+
+		tx_buf = kzalloc(sizeof(struct ishtp_cl_tx_ring), GFP_KERNEL);
+		if (!tx_buf)
+			goto	out;
+
+		tx_buf->send_buf.data = kmalloc(len, GFP_KERNEL);
+		if (!tx_buf->send_buf.data) {
+			kfree(tx_buf);
+			goto	out;
+		}
+
+		spin_lock_irqsave(&cl->tx_free_list_spinlock, flags);
+		list_add_tail(&tx_buf->list, &cl->tx_free_list.list);
+		++cl->tx_ring_free_size;
+		spin_unlock_irqrestore(&cl->tx_free_list_spinlock, flags);
+	}
+	return	0;
+out:
+	dev_err(&cl->device->dev, "error in allocating Tx pool\n");
+	ishtp_cl_free_tx_ring(cl);
+	return	-ENOMEM;
+}
+
+/**
+ * ishtp_cl_free_rx_ring() - Free RX ring buffers
+ * @cl: client device instance
+ *
+ * Free RX ring buffers
+ */
+void ishtp_cl_free_rx_ring(struct ishtp_cl *cl)
+{
+	struct ishtp_cl_rb *rb;
+	unsigned long	flags;
+
+	/* release allocated memory - pass over free_rb_list */
+	spin_lock_irqsave(&cl->free_list_spinlock, flags);
+	while (!list_empty(&cl->free_rb_list.list)) {
+		rb = list_entry(cl->free_rb_list.list.next, struct ishtp_cl_rb,
+				list);
+		list_del(&rb->list);
+		kfree(rb->buffer.data);
+		kfree(rb);
+	}
+	spin_unlock_irqrestore(&cl->free_list_spinlock, flags);
+	/* release allocated memory - pass over in_process_list */
+	spin_lock_irqsave(&cl->in_process_spinlock, flags);
+	while (!list_empty(&cl->in_process_list.list)) {
+		rb = list_entry(cl->in_process_list.list.next,
+				struct ishtp_cl_rb, list);
+		list_del(&rb->list);
+		kfree(rb->buffer.data);
+		kfree(rb);
+	}
+	spin_unlock_irqrestore(&cl->in_process_spinlock, flags);
+}
+
+/**
+ * ishtp_cl_free_tx_ring() - Free TX ring buffers
+ * @cl: client device instance
+ *
+ * Free TX ring buffers
+ */
+void ishtp_cl_free_tx_ring(struct ishtp_cl *cl)
+{
+	struct ishtp_cl_tx_ring	*tx_buf;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&cl->tx_free_list_spinlock, flags);
+	/* release allocated memory - pass over tx_free_list */
+	while (!list_empty(&cl->tx_free_list.list)) {
+		tx_buf = list_entry(cl->tx_free_list.list.next,
+				    struct ishtp_cl_tx_ring, list);
+		list_del(&tx_buf->list);
+		--cl->tx_ring_free_size;
+		kfree(tx_buf->send_buf.data);
+		kfree(tx_buf);
+	}
+	spin_unlock_irqrestore(&cl->tx_free_list_spinlock, flags);
+
+	spin_lock_irqsave(&cl->tx_list_spinlock, flags);
+	/* release allocated memory - pass over tx_list */
+	while (!list_empty(&cl->tx_list.list)) {
+		tx_buf = list_entry(cl->tx_list.list.next,
+				    struct ishtp_cl_tx_ring, list);
+		list_del(&tx_buf->list);
+		kfree(tx_buf->send_buf.data);
+		kfree(tx_buf);
+	}
+	spin_unlock_irqrestore(&cl->tx_list_spinlock, flags);
+}
+
+/**
+ * ishtp_io_rb_free() - Free IO request block
+ * @rb: IO request block
+ *
+ * Free io request block memory
+ */
+void ishtp_io_rb_free(struct ishtp_cl_rb *rb)
+{
+	if (rb == NULL)
+		return;
+
+	kfree(rb->buffer.data);
+	kfree(rb);
+}
+
+/**
+ * ishtp_io_rb_init() - Allocate and init IO request block
+ * @cl: client device instance
+ *
+ * Allocate and initialize request block
+ *
+ * Return: Allocted IO request block pointer
+ */
+struct ishtp_cl_rb *ishtp_io_rb_init(struct ishtp_cl *cl)
+{
+	struct ishtp_cl_rb *rb;
+
+	rb = kzalloc(sizeof(struct ishtp_cl_rb), GFP_KERNEL);
+	if (!rb)
+		return NULL;
+
+	INIT_LIST_HEAD(&rb->list);
+	rb->cl = cl;
+	rb->buf_idx = 0;
+	return rb;
+}
+
+/**
+ * ishtp_io_rb_alloc_buf() - Allocate and init response buffer
+ * @rb: IO request block
+ * @length: length of response buffer
+ *
+ * Allocate respose buffer
+ *
+ * Return: 0 on success else -ENOMEM
+ */
+int ishtp_io_rb_alloc_buf(struct ishtp_cl_rb *rb, size_t length)
+{
+	if (!rb)
+		return -EINVAL;
+
+	if (length == 0)
+		return 0;
+
+	rb->buffer.data = kmalloc(length, GFP_KERNEL);
+	if (!rb->buffer.data)
+		return -ENOMEM;
+
+	rb->buffer.size = length;
+	return 0;
+}
+
+/**
+ * ishtp_cl_io_rb_recycle() - Recycle IO request blocks
+ * @rb: IO request block
+ *
+ * Re-append rb to its client's free list and send flow control if needed
+ *
+ * Return: 0 on success else -EFAULT
+ */
+int ishtp_cl_io_rb_recycle(struct ishtp_cl_rb *rb)
+{
+	struct ishtp_cl *cl;
+	int	rets = 0;
+	unsigned long	flags;
+
+	if (!rb || !rb->cl)
+		return	-EFAULT;
+
+	cl = rb->cl;
+	spin_lock_irqsave(&cl->free_list_spinlock, flags);
+	list_add_tail(&rb->list, &cl->free_rb_list.list);
+	spin_unlock_irqrestore(&cl->free_list_spinlock, flags);
+
+	/*
+	 * If we returned the first buffer to empty 'free' list,
+	 * send flow control
+	 */
+	if (!cl->out_flow_ctrl_creds)
+		rets = ishtp_cl_read_start(cl);
+
+	return	rets;
+}
+EXPORT_SYMBOL(ishtp_cl_io_rb_recycle);
+
+/**
+ * ishtp_cl_tx_empty() -test whether client device tx buffer is empty
+ * @cl: Pointer to client device instance
+ *
+ * Look client device tx buffer list, and check whether this list is empty
+ *
+ * Return: true if client tx buffer list is empty else false
+ */
+bool ishtp_cl_tx_empty(struct ishtp_cl *cl)
+{
+	int tx_list_empty;
+	unsigned long tx_flags;
+
+	spin_lock_irqsave(&cl->tx_list_spinlock, tx_flags);
+	tx_list_empty = list_empty(&cl->tx_list.list);
+	spin_unlock_irqrestore(&cl->tx_list_spinlock, tx_flags);
+
+	return !!tx_list_empty;
+}
+EXPORT_SYMBOL(ishtp_cl_tx_empty);
+
+/**
+ * ishtp_cl_rx_get_rb() -Get a rb from client device rx buffer list
+ * @cl: Pointer to client device instance
+ *
+ * Check client device in-processing buffer list and get a rb from it.
+ *
+ * Return: rb pointer if buffer list isn't empty else NULL
+ */
+struct ishtp_cl_rb *ishtp_cl_rx_get_rb(struct ishtp_cl *cl)
+{
+	unsigned long rx_flags;
+	struct ishtp_cl_rb *rb;
+
+	spin_lock_irqsave(&cl->in_process_spinlock, rx_flags);
+	rb = list_first_entry_or_null(&cl->in_process_list.list,
+				struct ishtp_cl_rb, list);
+	if (rb)
+		list_del_init(&rb->list);
+	spin_unlock_irqrestore(&cl->in_process_spinlock, rx_flags);
+
+	return rb;
+}
+EXPORT_SYMBOL(ishtp_cl_rx_get_rb);