v4.19.13 snapshot.
diff --git a/drivers/hid/intel-ish-hid/ishtp/dma-if.c b/drivers/hid/intel-ish-hid/ishtp/dma-if.c
new file mode 100644
index 0000000..2783f36
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ishtp/dma-if.c
@@ -0,0 +1,175 @@
+/*
+ * ISHTP DMA I/F functions
+ *
+ * Copyright (c) 2003-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/delay.h>
+#include <linux/dma-mapping.h>
+#include "ishtp-dev.h"
+#include "client.h"
+
+/**
+ * ishtp_cl_alloc_dma_buf() - Allocate DMA RX and TX buffer
+ * @dev: ishtp device
+ *
+ * Allocate RX and TX DMA buffer once during bus setup.
+ * It allocates 1MB, RX and TX DMA buffer, which are divided
+ * into slots.
+ */
+void ishtp_cl_alloc_dma_buf(struct ishtp_device *dev)
+{
+ dma_addr_t h;
+
+ if (dev->ishtp_host_dma_tx_buf)
+ return;
+
+ dev->ishtp_host_dma_tx_buf_size = 1024*1024;
+ dev->ishtp_host_dma_rx_buf_size = 1024*1024;
+
+ /* Allocate Tx buffer and init usage bitmap */
+ dev->ishtp_host_dma_tx_buf = dma_alloc_coherent(dev->devc,
+ dev->ishtp_host_dma_tx_buf_size,
+ &h, GFP_KERNEL);
+ if (dev->ishtp_host_dma_tx_buf)
+ dev->ishtp_host_dma_tx_buf_phys = h;
+
+ dev->ishtp_dma_num_slots = dev->ishtp_host_dma_tx_buf_size /
+ DMA_SLOT_SIZE;
+
+ dev->ishtp_dma_tx_map = kcalloc(dev->ishtp_dma_num_slots,
+ sizeof(uint8_t),
+ GFP_KERNEL);
+ spin_lock_init(&dev->ishtp_dma_tx_lock);
+
+ /* Allocate Rx buffer */
+ dev->ishtp_host_dma_rx_buf = dma_alloc_coherent(dev->devc,
+ dev->ishtp_host_dma_rx_buf_size,
+ &h, GFP_KERNEL);
+
+ if (dev->ishtp_host_dma_rx_buf)
+ dev->ishtp_host_dma_rx_buf_phys = h;
+}
+
+/**
+ * ishtp_cl_free_dma_buf() - Free DMA RX and TX buffer
+ * @dev: ishtp device
+ *
+ * Free DMA buffer when all clients are released. This is
+ * only happens during error path in ISH built in driver
+ * model
+ */
+void ishtp_cl_free_dma_buf(struct ishtp_device *dev)
+{
+ dma_addr_t h;
+
+ if (dev->ishtp_host_dma_tx_buf) {
+ h = dev->ishtp_host_dma_tx_buf_phys;
+ dma_free_coherent(dev->devc, dev->ishtp_host_dma_tx_buf_size,
+ dev->ishtp_host_dma_tx_buf, h);
+ }
+
+ if (dev->ishtp_host_dma_rx_buf) {
+ h = dev->ishtp_host_dma_rx_buf_phys;
+ dma_free_coherent(dev->devc, dev->ishtp_host_dma_rx_buf_size,
+ dev->ishtp_host_dma_rx_buf, h);
+ }
+
+ kfree(dev->ishtp_dma_tx_map);
+ dev->ishtp_host_dma_tx_buf = NULL;
+ dev->ishtp_host_dma_rx_buf = NULL;
+ dev->ishtp_dma_tx_map = NULL;
+}
+
+/*
+ * ishtp_cl_get_dma_send_buf() - Get a DMA memory slot
+ * @dev: ishtp device
+ * @size: Size of memory to get
+ *
+ * Find and return free address of "size" bytes in dma tx buffer.
+ * the function will mark this address as "in-used" memory.
+ *
+ * Return: NULL when no free buffer else a buffer to copy
+ */
+void *ishtp_cl_get_dma_send_buf(struct ishtp_device *dev,
+ uint32_t size)
+{
+ unsigned long flags;
+ int i, j, free;
+ /* additional slot is needed if there is rem */
+ int required_slots = (size / DMA_SLOT_SIZE)
+ + 1 * (size % DMA_SLOT_SIZE != 0);
+
+ spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags);
+ for (i = 0; i <= (dev->ishtp_dma_num_slots - required_slots); i++) {
+ free = 1;
+ for (j = 0; j < required_slots; j++)
+ if (dev->ishtp_dma_tx_map[i+j]) {
+ free = 0;
+ i += j;
+ break;
+ }
+ if (free) {
+ /* mark memory as "caught" */
+ for (j = 0; j < required_slots; j++)
+ dev->ishtp_dma_tx_map[i+j] = 1;
+ spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
+ return (i * DMA_SLOT_SIZE) +
+ (unsigned char *)dev->ishtp_host_dma_tx_buf;
+ }
+ }
+ spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
+ dev_err(dev->devc, "No free DMA buffer to send msg\n");
+ return NULL;
+}
+
+/*
+ * ishtp_cl_release_dma_acked_mem() - Release DMA memory slot
+ * @dev: ishtp device
+ * @msg_addr: message address of slot
+ * @size: Size of memory to get
+ *
+ * Release_dma_acked_mem - returnes the acked memory to free list.
+ * (from msg_addr, size bytes long)
+ */
+void ishtp_cl_release_dma_acked_mem(struct ishtp_device *dev,
+ void *msg_addr,
+ uint8_t size)
+{
+ unsigned long flags;
+ int acked_slots = (size / DMA_SLOT_SIZE)
+ + 1 * (size % DMA_SLOT_SIZE != 0);
+ int i, j;
+
+ if ((msg_addr - dev->ishtp_host_dma_tx_buf) % DMA_SLOT_SIZE) {
+ dev_err(dev->devc, "Bad DMA Tx ack address\n");
+ return;
+ }
+
+ i = (msg_addr - dev->ishtp_host_dma_tx_buf) / DMA_SLOT_SIZE;
+ spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags);
+ for (j = 0; j < acked_slots; j++) {
+ if ((i + j) >= dev->ishtp_dma_num_slots ||
+ !dev->ishtp_dma_tx_map[i+j]) {
+ /* no such slot, or memory is already free */
+ spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
+ dev_err(dev->devc, "Bad DMA Tx ack address\n");
+ return;
+ }
+ dev->ishtp_dma_tx_map[i+j] = 0;
+ }
+ spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags);
+}