1 files changed, 275 insertions, 0 deletions
diff --git a/drivers/hid/intel-ish-hid/ishtp/loader.c b/drivers/hid/intel-ish-hid/ishtp/loader.c
new file mode 100644
index 000000000000..993f8b390e57
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ishtp/loader.c
@@ -0,0 +1,275 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * ISHTP firmware loader function
+ *
+ * Copyright (c) 2024, Intel Corporation.
+ *
+ * This module implements the functionality to load the main ISH firmware from the host, starting
+ * with the Lunar Lake generation. It leverages a new method that enhances space optimization and
+ * flexibility by dividing the ISH firmware into a bootloader and main firmware.
+ *
+ * Please refer to the [Documentation](Documentation/hid/intel-ish-hid.rst) for the details on
+ * flows.
+ *
+ * Additionally, address potential error scenarios to ensure graceful failure handling.
+ * - Firmware Image Not Found:
+ *   Occurs when `request_firmware()` cannot locate the firmware image. The ISH firmware will
+ *   remain in a state awaiting firmware loading from the host, with no further action from
+ *   the ISHTP driver.
+ *   Recovery: Re-insmod the ISH drivers allows for a retry of the firmware loading from the host.
+ *
+ * - DMA Buffer Allocation Failure:
+ *   This happens if allocating a DMA buffer during `prepare_dma_bufs()` fails. The ISH firmware
+ *   will stay in a waiting state, and the ISHTP driver will release any allocated DMA buffers and
+ *   firmware without further actions.
+ *   Recovery: Re-insmod the ISH drivers allows for a retry of the firmware loading from the host.
+ *
+ * - Incorrect Firmware Image:
+ *   Using an incorrect firmware image will initiate the firmware loading process but will
+ *   eventually be refused by the ISH firmware after three unsuccessful attempts, indicated by
+ *   returning an error code. The ISHTP driver will stop attempting after three tries.
+ *   Recovery: A platform reset is required to retry firmware loading from the host.
+ */
+
+#define dev_fmt(fmt) "ISH loader: " fmt
+
+#include <linux/cacheflush.h>
+#include <linux/container_of.h>
+#include <linux/dev_printk.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/firmware.h>
+#include <linux/gfp_types.h>
+#include <linux/math.h>
+#include <linux/module.h>
+#include <linux/pfn.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/wait.h>
+
+#include "hbm.h"
+#include "loader.h"
+
+/**
+ * loader_write_message() - Write a message to the ISHTP device
+ * @dev: The ISHTP device
+ * @buf: The buffer containing the message
+ * @len: The length of the message
+ *
+ * Return: 0 on success, negative error code on failure
+ */
+static int loader_write_message(struct ishtp_device *dev, void *buf, int len)
+{
+	struct ishtp_msg_hdr ishtp_hdr = {
+		.fw_addr = ISHTP_LOADER_CLIENT_ADDR,
+		.length = len,
+		.msg_complete = 1,
+	};
+
+	dev->fw_loader_received = false;
+
+	return ishtp_write_message(dev, &ishtp_hdr, buf);
+}
+
+/**
+ * loader_xfer_cmd() - Transfer a command to the ISHTP device
+ * @dev: The ISHTP device
+ * @req: The request buffer
+ * @req_len: The length of the request
+ * @resp: The response buffer
+ * @resp_len: The length of the response
+ *
+ * Return: 0 on success, negative error code on failure
+ */
+static int loader_xfer_cmd(struct ishtp_device *dev, void *req, int req_len,
+			   void *resp, int resp_len)
+{
+	struct loader_msg_header *req_hdr = req;
+	struct loader_msg_header *resp_hdr = resp;
+	struct device *devc = dev->devc;
+	int rv;
+
+	dev->fw_loader_rx_buf = resp;
+	dev->fw_loader_rx_size = resp_len;
+
+	rv = loader_write_message(dev, req, req_len);
+	if (rv < 0) {
+		dev_err(devc, "write cmd %u failed:%d\n", req_hdr->command, rv);
+		return rv;
+	}
+
+	/* Wait the ACK */
+	wait_event_interruptible_timeout(dev->wait_loader_recvd_msg, dev->fw_loader_received,
+					 ISHTP_LOADER_TIMEOUT);
+	dev->fw_loader_rx_size = 0;
+	dev->fw_loader_rx_buf = NULL;
+	if (!dev->fw_loader_received) {
+		dev_err(devc, "wait response of cmd %u timeout\n", req_hdr->command);
+		return -ETIMEDOUT;
+	}
+
+	if (!resp_hdr->is_response) {
+		dev_err(devc, "not a response for %u\n", req_hdr->command);
+		return -EBADMSG;
+	}
+
+	if (req_hdr->command != resp_hdr->command) {
+		dev_err(devc, "unexpected cmd response %u:%u\n", req_hdr->command,
+			resp_hdr->command);
+		return -EBADMSG;
+	}
+
+	if (resp_hdr->status) {
+		dev_err(devc, "cmd %u failed %u\n", req_hdr->command, resp_hdr->status);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ * release_dma_bufs() - Release the DMA buffer for transferring firmware fragments
+ * @dev: The ISHTP device
+ * @fragment: The ISHTP firmware fragment descriptor
+ * @dma_bufs: The array of DMA fragment buffers
+ * @fragment_size: The size of a single DMA fragment
+ */
+static void release_dma_bufs(struct ishtp_device *dev,
+			     struct loader_xfer_dma_fragment *fragment,
+			     void **dma_bufs, u32 fragment_size)
+{
+	int i;
+
+	for (i = 0; i < FRAGMENT_MAX_NUM; i++) {
+		if (dma_bufs[i]) {
+			dma_free_coherent(dev->devc, fragment_size, dma_bufs[i],
+					  fragment->fragment_tbl[i].ddr_adrs);
+			dma_bufs[i] = NULL;
+		}
+	}
+}
+
+/**
+ * prepare_dma_bufs() - Prepare the DMA buffer for transferring firmware fragments
+ * @dev: The ISHTP device
+ * @ish_fw: The ISH firmware
+ * @fragment: The ISHTP firmware fragment descriptor
+ * @dma_bufs: The array of DMA fragment buffers
+ * @fragment_size: The size of a single DMA fragment
+ *
+ * Return: 0 on success, negative error code on failure
+ */
+static int prepare_dma_bufs(struct ishtp_device *dev,
+			    const struct firmware *ish_fw,
+			    struct loader_xfer_dma_fragment *fragment,
+			    void **dma_bufs, u32 fragment_size)
+{
+	u32 offset = 0;
+	int i;
+
+	for (i = 0; i < fragment->fragment_cnt && offset < ish_fw->size; i++) {
+		dma_bufs[i] = dma_alloc_coherent(dev->devc, fragment_size,
+						 &fragment->fragment_tbl[i].ddr_adrs, GFP_KERNEL);
+		if (!dma_bufs[i])
+			return -ENOMEM;
+
+		fragment->fragment_tbl[i].length = clamp(ish_fw->size - offset, 0, fragment_size);
+		fragment->fragment_tbl[i].fw_off = offset;
+		memcpy(dma_bufs[i], ish_fw->data + offset, fragment->fragment_tbl[i].length);
+		clflush_cache_range(dma_bufs[i], fragment_size);
+
+		offset += fragment->fragment_tbl[i].length;
+	}
+
+	return 0;
+}
+
+/**
+ * ishtp_loader_work() - Load the ISHTP firmware
+ * @work: The work structure
+ *
+ * The ISH Loader attempts to load firmware by sending a series of commands
+ * to the ISH device. If a command fails to be acknowledged by the ISH device,
+ * the loader will retry sending the command, up to a maximum of
+ * ISHTP_LOADER_RETRY_TIMES.
+ *
+ * After the maximum number of retries has been reached without success, the
+ * ISH bootloader will return an error status code and will no longer respond
+ * to the driver's commands. This behavior indicates that the ISH Loader has
+ * encountered a critical error during the firmware loading process.
+ *
+ * In such a case, where the ISH bootloader is unresponsive after all retries
+ * have been exhausted, a platform reset is required to restore communication
+ * with the ISH device and to recover from this error state.
+ */
+void ishtp_loader_work(struct work_struct *work)
+{
+	DEFINE_RAW_FLEX(struct loader_xfer_dma_fragment, fragment, fragment_tbl, FRAGMENT_MAX_NUM);
+	struct ishtp_device *dev = container_of(work, struct ishtp_device, work_fw_loader);
+	struct loader_xfer_query query = {
+		.header.command = LOADER_CMD_XFER_QUERY,
+	};
+	struct loader_start start = {
+		.header.command = LOADER_CMD_START,
+	};
+	union loader_recv_message recv_msg;
+	char *filename = dev->driver_data->fw_filename;
+	const struct firmware *ish_fw;
+	void *dma_bufs[FRAGMENT_MAX_NUM] = {};
+	u32 fragment_size;
+	int retry = ISHTP_LOADER_RETRY_TIMES;
+	int rv;
+
+	rv = request_firmware(&ish_fw, filename, dev->devc);
+	if (rv < 0) {
+		dev_err(dev->devc, "request firmware %s failed:%d\n", filename, rv);
+		return;
+	}
+
+	fragment->fragment.header.command = LOADER_CMD_XFER_FRAGMENT;
+	fragment->fragment.xfer_mode = LOADER_XFER_MODE_DMA;
+	fragment->fragment.is_last = 1;
+	fragment->fragment.size = ish_fw->size;
+	/* Calculate the size of a single DMA fragment */
+	fragment_size = PFN_ALIGN(DIV_ROUND_UP(ish_fw->size, FRAGMENT_MAX_NUM));
+	/* Calculate the count of DMA fragments */
+	fragment->fragment_cnt = DIV_ROUND_UP(ish_fw->size, fragment_size);
+
+	rv = prepare_dma_bufs(dev, ish_fw, fragment, dma_bufs, fragment_size);
+	if (rv) {
+		dev_err(dev->devc, "prepare DMA buffer failed.\n");
+		goto out;
+	}
+
+	do {
+		query.image_size = ish_fw->size;
+		rv = loader_xfer_cmd(dev, &query, sizeof(query), recv_msg.raw_data,
+				     sizeof(struct loader_xfer_query_ack));
+		if (rv)
+			continue; /* try again if failed */
+
+		dev_dbg(dev->devc, "ISH Version %u.%u.%u.%u\n",
+			recv_msg.query_ack.version_major,
+			recv_msg.query_ack.version_minor,
+			recv_msg.query_ack.version_hotfix,
+			recv_msg.query_ack.version_build);
+
+		rv = loader_xfer_cmd(dev, fragment,
+				     struct_size(fragment, fragment_tbl, fragment->fragment_cnt),
+				     recv_msg.raw_data, sizeof(struct loader_xfer_fragment_ack));
+		if (rv)
+			continue; /* try again if failed */
+
+		rv = loader_xfer_cmd(dev, &start, sizeof(start), recv_msg.raw_data,
+				     sizeof(struct loader_start_ack));
+		if (rv)
+			continue; /* try again if failed */
+
+		dev_info(dev->devc, "firmware loaded. size:%zu\n", ish_fw->size);
+		break;
+	} while (--retry);
+
+out:
+	release_dma_bufs(dev, fragment, dma_bufs, fragment_size);
+	release_firmware(ish_fw);
+}