HID: intel-ish-hid: Implement loading firmware from host feature

Starting from the Lunar Lake generation, the ISH firmware has been
divided into two components for better space optimization and increased
flexibility. These components include a bootloader that is integrated
into the BIOS, and a main firmware that is stored within the operating
system's file system.

Introduce support for loading ISH main firmware from host. This feature is
applicable for Lunar Lake and later generation.

Current intel-ishtp-loader, is designed for Chrome OS based systems which
uses core boot and has different firmware loading method. For non chrome
systems the ISH firmware loading uses different method.

Key differences include:
1. The new method utilizes ISHTP capability/fixed client to enumerate the
firmware loader function. It does not require a connection or flow control,
unlike the method used in Chrome OS, which is enumerated as an ISHTP
dynamic client driver, necessitating connect/disconnect operations and flow
control.

2. The new method employs a table to describe firmware fragments, which are
sent to ISH in a single operation. Conversely, the Chrome OS method sends
firmware fragments in multiple operations within a loop, sending only one
fragment at a time.

Additionally, address potential error scenarios to ensure graceful failure
handling.
- Firmware Not Found: Triggers if request_firmware() fails, leaving ISH in
  a waiting state.
  Recovery: Re-insmod the ISH drivers to retry.

- DMA Buffer Allocation Failure: Occurs during prepare_dma_bufs(), leading
  to ISH waiting state. Allocated resources are released.
  Recovery: Re-insmod the ISH drivers to retry.

- Incorrect Firmware Image: Causes ISH to refuse loading after three failed
  attempts.
  Recovery: A platform reset is required.

Please refer to the [Documentation](Documentation/hid/intel-ish-hid.rst)
for the details on flows.

Signed-off-by: Zhang Lixu <lixu.zhang@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

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);
+}