8 files changed, 864 insertions, 2 deletions

diff --git a/drivers/accel/qaic/Makefile b/drivers/accel/qaic/Makefile
index 3f7f6dfde7..35e8835156 100644
--- a/drivers/accel/qaic/Makefile
+++ b/drivers/accel/qaic/Makefile
@@ -10,4 +10,7 @@ qaic-y := \
 	qaic_control.o \
 	qaic_data.o \
 	qaic_drv.o \
-	qaic_timesync.o
+	qaic_timesync.o \
+	sahara.o
+
+qaic-$(CONFIG_DEBUG_FS) += qaic_debugfs.o
diff --git a/drivers/accel/qaic/qaic.h b/drivers/accel/qaic/qaic.h
index 9256653b30..02561b6cec 100644
--- a/drivers/accel/qaic/qaic.h
+++ b/drivers/accel/qaic/qaic.h
@@ -153,6 +153,14 @@ struct qaic_device {
 	struct mhi_device	*qts_ch;
 	/* Work queue for tasks related to MHI "QAIC_TIMESYNC" channel */
 	struct workqueue_struct	*qts_wq;
+	/* Head of list of page allocated by MHI bootlog device */
+	struct list_head        bootlog;
+	/* MHI bootlog channel device */
+	struct mhi_device       *bootlog_ch;
+	/* Work queue for tasks related to MHI bootlog device */
+	struct workqueue_struct *bootlog_wq;
+	/* Synchronizes access of pages in MHI bootlog device */
+	struct mutex            bootlog_mutex;
 };
 
 struct qaic_drm_device {
@@ -280,6 +288,7 @@ int disable_dbc(struct qaic_device *qdev, u32 dbc_id, struct qaic_user *usr);
 void enable_dbc(struct qaic_device *qdev, u32 dbc_id, struct qaic_user *usr);
 void wakeup_dbc(struct qaic_device *qdev, u32 dbc_id);
 void release_dbc(struct qaic_device *qdev, u32 dbc_id);
+void qaic_data_get_fifo_info(struct dma_bridge_chan *dbc, u32 *head, u32 *tail);
 
 void wake_all_cntl(struct qaic_device *qdev);
 void qaic_dev_reset_clean_local_state(struct qaic_device *qdev);
diff --git a/drivers/accel/qaic/qaic_data.c b/drivers/accel/qaic/qaic_data.c
index 2459fe4a3f..e86e71c1cd 100644
--- a/drivers/accel/qaic/qaic_data.c
+++ b/drivers/accel/qaic/qaic_data.c
@@ -1981,3 +1981,12 @@ void release_dbc(struct qaic_device *qdev, u32 dbc_id)
 	dbc->in_use = false;
 	wake_up(&dbc->dbc_release);
 }
+
+void qaic_data_get_fifo_info(struct dma_bridge_chan *dbc, u32 *head, u32 *tail)
+{
+	if (!dbc || !head || !tail)
+		return;
+
+	*head = readl(dbc->dbc_base + REQHP_OFF);
+	*tail = readl(dbc->dbc_base + REQTP_OFF);
+}
diff --git a/drivers/accel/qaic/qaic_debugfs.c b/drivers/accel/qaic/qaic_debugfs.c
new file mode 100644
index 0000000000..20b653d99e
--- /dev/null
+++ b/drivers/accel/qaic/qaic_debugfs.c
@@ -0,0 +1,338 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/* Copyright (c) 2020, The Linux Foundation. All rights reserved. */
+/* Copyright (c) 2021-2024 Qualcomm Innovation Center, Inc. All rights reserved. */
+
+#include <linux/debugfs.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/list.h>
+#include <linux/mhi.h>
+#include <linux/mutex.h>
+#include <linux/overflow.h>
+#include <linux/pci.h>
+#include <linux/seq_file.h>
+#include <linux/sprintf.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#include "qaic.h"
+#include "qaic_debugfs.h"
+
+#define BOOTLOG_POOL_SIZE		16
+#define BOOTLOG_MSG_SIZE		512
+#define QAIC_DBC_DIR_NAME		9
+
+struct bootlog_msg {
+	/* Buffer for bootlog messages */
+	char str[BOOTLOG_MSG_SIZE];
+	/* Root struct of device, used to access device resources */
+	struct qaic_device *qdev;
+	/* Work struct to schedule work coming on QAIC_LOGGING channel */
+	struct work_struct work;
+};
+
+struct bootlog_page {
+	/* Node in list of bootlog pages maintained by root device struct */
+	struct list_head node;
+	/* Total size of the buffer that holds the bootlogs. It is PAGE_SIZE */
+	unsigned int size;
+	/* Offset for the next bootlog */
+	unsigned int offset;
+};
+
+static int bootlog_show(struct seq_file *s, void *unused)
+{
+	struct bootlog_page *page;
+	struct qaic_device *qdev;
+	void *page_end;
+	void *log;
+
+	qdev = s->private;
+	mutex_lock(&qdev->bootlog_mutex);
+	list_for_each_entry(page, &qdev->bootlog, node) {
+		log = page + 1;
+		page_end = (void *)page + page->offset;
+		while (log < page_end) {
+			seq_printf(s, "%s", (char *)log);
+			log += strlen(log) + 1;
+		}
+	}
+	mutex_unlock(&qdev->bootlog_mutex);
+
+	return 0;
+}
+
+static int bootlog_fops_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, bootlog_show, inode->i_private);
+}
+
+static const struct file_operations bootlog_fops = {
+	.owner = THIS_MODULE,
+	.open = bootlog_fops_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int read_dbc_fifo_size(struct seq_file *s, void *unused)
+{
+	struct dma_bridge_chan *dbc = s->private;
+
+	seq_printf(s, "%u\n", dbc->nelem);
+	return 0;
+}
+
+static int fifo_size_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, read_dbc_fifo_size, inode->i_private);
+}
+
+static const struct file_operations fifo_size_fops = {
+	.owner = THIS_MODULE,
+	.open = fifo_size_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int read_dbc_queued(struct seq_file *s, void *unused)
+{
+	struct dma_bridge_chan *dbc = s->private;
+	u32 tail = 0, head = 0;
+
+	qaic_data_get_fifo_info(dbc, &head, &tail);
+
+	if (head == U32_MAX || tail == U32_MAX)
+		seq_printf(s, "%u\n", 0);
+	else if (head > tail)
+		seq_printf(s, "%u\n", dbc->nelem - head + tail);
+	else
+		seq_printf(s, "%u\n", tail - head);
+
+	return 0;
+}
+
+static int queued_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, read_dbc_queued, inode->i_private);
+}
+
+static const struct file_operations queued_fops = {
+	.owner = THIS_MODULE,
+	.open = queued_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+void qaic_debugfs_init(struct qaic_drm_device *qddev)
+{
+	struct qaic_device *qdev = qddev->qdev;
+	struct dentry *debugfs_root;
+	struct dentry *debugfs_dir;
+	char name[QAIC_DBC_DIR_NAME];
+	u32 i;
+
+	debugfs_root = to_drm(qddev)->debugfs_root;
+
+	debugfs_create_file("bootlog", 0400, debugfs_root, qdev, &bootlog_fops);
+	/*
+	 * 256 dbcs per device is likely the max we will ever see and lets static checking see a
+	 * reasonable range.
+	 */
+	for (i = 0; i < qdev->num_dbc && i < 256; ++i) {
+		snprintf(name, QAIC_DBC_DIR_NAME, "dbc%03u", i);
+		debugfs_dir = debugfs_create_dir(name, debugfs_root);
+		debugfs_create_file("fifo_size", 0400, debugfs_dir, &qdev->dbc[i], &fifo_size_fops);
+		debugfs_create_file("queued", 0400, debugfs_dir, &qdev->dbc[i], &queued_fops);
+	}
+}
+
+static struct bootlog_page *alloc_bootlog_page(struct qaic_device *qdev)
+{
+	struct bootlog_page *page;
+
+	page = (struct bootlog_page *)devm_get_free_pages(&qdev->pdev->dev, GFP_KERNEL, 0);
+	if (!page)
+		return page;
+
+	page->size = PAGE_SIZE;
+	page->offset = sizeof(*page);
+	list_add_tail(&page->node, &qdev->bootlog);
+
+	return page;
+}
+
+static int reset_bootlog(struct qaic_device *qdev)
+{
+	struct bootlog_page *page;
+	struct bootlog_page *i;
+
+	mutex_lock(&qdev->bootlog_mutex);
+	list_for_each_entry_safe(page, i, &qdev->bootlog, node) {
+		list_del(&page->node);
+		devm_free_pages(&qdev->pdev->dev, (unsigned long)page);
+	}
+
+	page = alloc_bootlog_page(qdev);
+	mutex_unlock(&qdev->bootlog_mutex);
+	if (!page)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void *bootlog_get_space(struct qaic_device *qdev, unsigned int size)
+{
+	struct bootlog_page *page;
+
+	page = list_last_entry(&qdev->bootlog, struct bootlog_page, node);
+
+	if (size_add(size, sizeof(*page)) > page->size)
+		return NULL;
+
+	if (page->offset + size > page->size) {
+		page = alloc_bootlog_page(qdev);
+		if (!page)
+			return NULL;
+	}
+
+	return (void *)page + page->offset;
+}
+
+static void bootlog_commit(struct qaic_device *qdev, unsigned int size)
+{
+	struct bootlog_page *page;
+
+	page = list_last_entry(&qdev->bootlog, struct bootlog_page, node);
+
+	page->offset += size;
+}
+
+static void bootlog_log(struct work_struct *work)
+{
+	struct bootlog_msg *msg = container_of(work, struct bootlog_msg, work);
+	unsigned int len = strlen(msg->str) + 1;
+	struct qaic_device *qdev = msg->qdev;
+	void *log;
+
+	mutex_lock(&qdev->bootlog_mutex);
+	log = bootlog_get_space(qdev, len);
+	if (log) {
+		memcpy(log, msg, len);
+		bootlog_commit(qdev, len);
+	}
+	mutex_unlock(&qdev->bootlog_mutex);
+
+	if (mhi_queue_buf(qdev->bootlog_ch, DMA_FROM_DEVICE, msg, BOOTLOG_MSG_SIZE, MHI_EOT))
+		devm_kfree(&qdev->pdev->dev, msg);
+}
+
+static int qaic_bootlog_mhi_probe(struct mhi_device *mhi_dev, const struct mhi_device_id *id)
+{
+	struct qaic_device *qdev = pci_get_drvdata(to_pci_dev(mhi_dev->mhi_cntrl->cntrl_dev));
+	struct bootlog_msg *msg;
+	int i, ret;
+
+	qdev->bootlog_wq = alloc_ordered_workqueue("qaic_bootlog", 0);
+	if (!qdev->bootlog_wq) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	ret = reset_bootlog(qdev);
+	if (ret)
+		goto destroy_workqueue;
+
+	ret = mhi_prepare_for_transfer(mhi_dev);
+	if (ret)
+		goto destroy_workqueue;
+
+	for (i = 0; i < BOOTLOG_POOL_SIZE; i++) {
+		msg = devm_kzalloc(&qdev->pdev->dev, sizeof(*msg), GFP_KERNEL);
+		if (!msg) {
+			ret = -ENOMEM;
+			goto mhi_unprepare;
+		}
+
+		msg->qdev = qdev;
+		INIT_WORK(&msg->work, bootlog_log);
+
+		ret = mhi_queue_buf(mhi_dev, DMA_FROM_DEVICE, msg, BOOTLOG_MSG_SIZE, MHI_EOT);
+		if (ret)
+			goto mhi_unprepare;
+	}
+
+	dev_set_drvdata(&mhi_dev->dev, qdev);
+	qdev->bootlog_ch = mhi_dev;
+	return 0;
+
+mhi_unprepare:
+	mhi_unprepare_from_transfer(mhi_dev);
+destroy_workqueue:
+	flush_workqueue(qdev->bootlog_wq);
+	destroy_workqueue(qdev->bootlog_wq);
+out:
+	return ret;
+}
+
+static void qaic_bootlog_mhi_remove(struct mhi_device *mhi_dev)
+{
+	struct qaic_device *qdev;
+
+	qdev = dev_get_drvdata(&mhi_dev->dev);
+
+	mhi_unprepare_from_transfer(qdev->bootlog_ch);
+	flush_workqueue(qdev->bootlog_wq);
+	destroy_workqueue(qdev->bootlog_wq);
+	qdev->bootlog_ch = NULL;
+}
+
+static void qaic_bootlog_mhi_ul_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result)
+{
+}
+
+static void qaic_bootlog_mhi_dl_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result)
+{
+	struct qaic_device *qdev = dev_get_drvdata(&mhi_dev->dev);
+	struct bootlog_msg *msg = mhi_result->buf_addr;
+
+	if (mhi_result->transaction_status) {
+		devm_kfree(&qdev->pdev->dev, msg);
+		return;
+	}
+
+	/* Force a null at the end of the transferred string */
+	msg->str[mhi_result->bytes_xferd - 1] = 0;
+
+	queue_work(qdev->bootlog_wq, &msg->work);
+}
+
+static const struct mhi_device_id qaic_bootlog_mhi_match_table[] = {
+	{ .chan = "QAIC_LOGGING", },
+	{},
+};
+
+static struct mhi_driver qaic_bootlog_mhi_driver = {
+	.id_table = qaic_bootlog_mhi_match_table,
+	.remove = qaic_bootlog_mhi_remove,
+	.probe = qaic_bootlog_mhi_probe,
+	.ul_xfer_cb = qaic_bootlog_mhi_ul_xfer_cb,
+	.dl_xfer_cb = qaic_bootlog_mhi_dl_xfer_cb,
+	.driver = {
+		.name = "qaic_bootlog",
+	},
+};
+
+int qaic_bootlog_register(void)
+{
+	return mhi_driver_register(&qaic_bootlog_mhi_driver);
+}
+
+void qaic_bootlog_unregister(void)
+{
+	mhi_driver_unregister(&qaic_bootlog_mhi_driver);
+}
diff --git a/drivers/accel/qaic/qaic_debugfs.h b/drivers/accel/qaic/qaic_debugfs.h
new file mode 100644
index 0000000000..05e74f84cf
--- /dev/null
+++ b/drivers/accel/qaic/qaic_debugfs.h
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/* Copyright (c) 2020, The Linux Foundation. All rights reserved. */
+/* Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved. */
+
+#ifndef __QAIC_DEBUGFS_H__
+#define __QAIC_DEBUGFS_H__
+
+#include <drm/drm_file.h>
+
+#ifdef CONFIG_DEBUG_FS
+int qaic_bootlog_register(void);
+void qaic_bootlog_unregister(void);
+void qaic_debugfs_init(struct qaic_drm_device *qddev);
+#else
+static inline int qaic_bootlog_register(void) { return 0; }
+static inline void qaic_bootlog_unregister(void) {}
+static inline void qaic_debugfs_init(struct qaic_drm_device *qddev) {}
+#endif /* CONFIG_DEBUG_FS */
+#endif /* __QAIC_DEBUGFS_H__ */
diff --git a/drivers/accel/qaic/qaic_drv.c b/drivers/accel/qaic/qaic_drv.c
index d1a632dbae..580b29ed19 100644
--- a/drivers/accel/qaic/qaic_drv.c
+++ b/drivers/accel/qaic/qaic_drv.c
@@ -28,7 +28,9 @@
 
 #include "mhi_controller.h"
 #include "qaic.h"
+#include "qaic_debugfs.h"
 #include "qaic_timesync.h"
+#include "sahara.h"
 
 MODULE_IMPORT_NS(DMA_BUF);
 
@@ -229,8 +231,12 @@ static int qaic_create_drm_device(struct qaic_device *qdev, s32 partition_id)
 	qddev->partition_id = partition_id;
 
 	ret = drm_dev_register(drm, 0);
-	if (ret)
+	if (ret) {
 		pci_dbg(qdev->pdev, "drm_dev_register failed %d\n", ret);
+		return ret;
+	}
+
+	qaic_debugfs_init(qddev);
 
 	return ret;
 }
@@ -382,6 +388,9 @@ static struct qaic_device *create_qdev(struct pci_dev *pdev, const struct pci_de
 	ret = drmm_mutex_init(drm, &qdev->cntl_mutex);
 	if (ret)
 		return NULL;
+	ret = drmm_mutex_init(drm, &qdev->bootlog_mutex);
+	if (ret)
+		return NULL;
 
 	qdev->cntl_wq = qaicm_wq_init(drm, "qaic_cntl");
 	if (IS_ERR(qdev->cntl_wq))
@@ -399,6 +408,7 @@ static struct qaic_device *create_qdev(struct pci_dev *pdev, const struct pci_de
 	qddev->qdev = qdev;
 
 	INIT_LIST_HEAD(&qdev->cntl_xfer_list);
+	INIT_LIST_HEAD(&qdev->bootlog);
 	INIT_LIST_HEAD(&qddev->users);
 
 	for (i = 0; i < qdev->num_dbc; ++i) {
@@ -635,12 +645,24 @@ static int __init qaic_init(void)
 		goto free_pci;
 	}
 
+	ret = sahara_register();
+	if (ret) {
+		pr_debug("qaic: sahara_register failed %d\n", ret);
+		goto free_mhi;
+	}
+
 	ret = qaic_timesync_init();
 	if (ret)
 		pr_debug("qaic: qaic_timesync_init failed %d\n", ret);
 
+	ret = qaic_bootlog_register();
+	if (ret)
+		pr_debug("qaic: qaic_bootlog_register failed %d\n", ret);
+
 	return 0;
 
+free_mhi:
+	mhi_driver_unregister(&qaic_mhi_driver);
 free_pci:
 	pci_unregister_driver(&qaic_pci_driver);
 	return ret;
@@ -664,7 +686,9 @@ static void __exit qaic_exit(void)
 	 * reinitializing the link_up state after the cleanup is done.
 	 */
 	link_up = true;
+	qaic_bootlog_unregister();
 	qaic_timesync_deinit();
+	sahara_unregister();
 	mhi_driver_unregister(&qaic_mhi_driver);
 	pci_unregister_driver(&qaic_pci_driver);
 }
diff --git a/drivers/accel/qaic/sahara.c b/drivers/accel/qaic/sahara.c
new file mode 100644
index 0000000000..bf94bbab6b
--- /dev/null
+++ b/drivers/accel/qaic/sahara.c
@@ -0,0 +1,449 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/* Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved. */
+
+#include <linux/firmware.h>
+#include <linux/limits.h>
+#include <linux/mhi.h>
+#include <linux/minmax.h>
+#include <linux/mod_devicetable.h>
+#include <linux/overflow.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
+#include "sahara.h"
+
+#define SAHARA_HELLO_CMD		0x1  /* Min protocol version 1.0 */
+#define SAHARA_HELLO_RESP_CMD		0x2  /* Min protocol version 1.0 */
+#define SAHARA_READ_DATA_CMD		0x3  /* Min protocol version 1.0 */
+#define SAHARA_END_OF_IMAGE_CMD		0x4  /* Min protocol version 1.0 */
+#define SAHARA_DONE_CMD			0x5  /* Min protocol version 1.0 */
+#define SAHARA_DONE_RESP_CMD		0x6  /* Min protocol version 1.0 */
+#define SAHARA_RESET_CMD		0x7  /* Min protocol version 1.0 */
+#define SAHARA_RESET_RESP_CMD		0x8  /* Min protocol version 1.0 */
+#define SAHARA_MEM_DEBUG_CMD		0x9  /* Min protocol version 2.0 */
+#define SAHARA_MEM_READ_CMD		0xa  /* Min protocol version 2.0 */
+#define SAHARA_CMD_READY_CMD		0xb  /* Min protocol version 2.1 */
+#define SAHARA_SWITCH_MODE_CMD		0xc  /* Min protocol version 2.1 */
+#define SAHARA_EXECUTE_CMD		0xd  /* Min protocol version 2.1 */
+#define SAHARA_EXECUTE_RESP_CMD		0xe  /* Min protocol version 2.1 */
+#define SAHARA_EXECUTE_DATA_CMD		0xf  /* Min protocol version 2.1 */
+#define SAHARA_MEM_DEBUG64_CMD		0x10 /* Min protocol version 2.5 */
+#define SAHARA_MEM_READ64_CMD		0x11 /* Min protocol version 2.5 */
+#define SAHARA_READ_DATA64_CMD		0x12 /* Min protocol version 2.8 */
+#define SAHARA_RESET_STATE_CMD		0x13 /* Min protocol version 2.9 */
+#define SAHARA_WRITE_DATA_CMD		0x14 /* Min protocol version 3.0 */
+
+#define SAHARA_PACKET_MAX_SIZE		0xffffU /* MHI_MAX_MTU */
+#define SAHARA_TRANSFER_MAX_SIZE	0x80000
+#define SAHARA_NUM_TX_BUF		DIV_ROUND_UP(SAHARA_TRANSFER_MAX_SIZE,\
+							SAHARA_PACKET_MAX_SIZE)
+#define SAHARA_IMAGE_ID_NONE		U32_MAX
+
+#define SAHARA_VERSION			2
+#define SAHARA_SUCCESS			0
+
+#define SAHARA_MODE_IMAGE_TX_PENDING	0x0
+#define SAHARA_MODE_IMAGE_TX_COMPLETE	0x1
+#define SAHARA_MODE_MEMORY_DEBUG	0x2
+#define SAHARA_MODE_COMMAND		0x3
+
+#define SAHARA_HELLO_LENGTH		0x30
+#define SAHARA_READ_DATA_LENGTH		0x14
+#define SAHARA_END_OF_IMAGE_LENGTH	0x10
+#define SAHARA_DONE_LENGTH		0x8
+#define SAHARA_RESET_LENGTH		0x8
+
+struct sahara_packet {
+	__le32 cmd;
+	__le32 length;
+
+	union {
+		struct {
+			__le32 version;
+			__le32 version_compat;
+			__le32 max_length;
+			__le32 mode;
+		} hello;
+		struct {
+			__le32 version;
+			__le32 version_compat;
+			__le32 status;
+			__le32 mode;
+		} hello_resp;
+		struct {
+			__le32 image;
+			__le32 offset;
+			__le32 length;
+		} read_data;
+		struct {
+			__le32 image;
+			__le32 status;
+		} end_of_image;
+	};
+};
+
+struct sahara_context {
+	struct sahara_packet		*tx[SAHARA_NUM_TX_BUF];
+	struct sahara_packet		*rx;
+	struct work_struct		work;
+	struct mhi_device		*mhi_dev;
+	const char			**image_table;
+	u32				table_size;
+	u32				active_image_id;
+	const struct firmware		*firmware;
+};
+
+static const char *aic100_image_table[] = {
+	[1]  = "qcom/aic100/fw1.bin",
+	[2]  = "qcom/aic100/fw2.bin",
+	[4]  = "qcom/aic100/fw4.bin",
+	[5]  = "qcom/aic100/fw5.bin",
+	[6]  = "qcom/aic100/fw6.bin",
+	[8]  = "qcom/aic100/fw8.bin",
+	[9]  = "qcom/aic100/fw9.bin",
+	[10] = "qcom/aic100/fw10.bin",
+};
+
+static int sahara_find_image(struct sahara_context *context, u32 image_id)
+{
+	int ret;
+
+	if (image_id == context->active_image_id)
+		return 0;
+
+	if (context->active_image_id != SAHARA_IMAGE_ID_NONE) {
+		dev_err(&context->mhi_dev->dev, "image id %d is not valid as %d is active\n",
+			image_id, context->active_image_id);
+		return -EINVAL;
+	}
+
+	if (image_id >= context->table_size || !context->image_table[image_id]) {
+		dev_err(&context->mhi_dev->dev, "request for unknown image: %d\n", image_id);
+		return -EINVAL;
+	}
+
+	/*
+	 * This image might be optional. The device may continue without it.
+	 * Only the device knows. Suppress error messages that could suggest an
+	 * a problem when we were actually able to continue.
+	 */
+	ret = firmware_request_nowarn(&context->firmware,
+				      context->image_table[image_id],
+				      &context->mhi_dev->dev);
+	if (ret) {
+		dev_dbg(&context->mhi_dev->dev, "request for image id %d / file %s failed %d\n",
+			image_id, context->image_table[image_id], ret);
+		return ret;
+	}
+
+	context->active_image_id = image_id;
+
+	return 0;
+}
+
+static void sahara_release_image(struct sahara_context *context)
+{
+	if (context->active_image_id != SAHARA_IMAGE_ID_NONE)
+		release_firmware(context->firmware);
+	context->active_image_id = SAHARA_IMAGE_ID_NONE;
+}
+
+static void sahara_send_reset(struct sahara_context *context)
+{
+	int ret;
+
+	context->tx[0]->cmd = cpu_to_le32(SAHARA_RESET_CMD);
+	context->tx[0]->length = cpu_to_le32(SAHARA_RESET_LENGTH);
+
+	ret = mhi_queue_buf(context->mhi_dev, DMA_TO_DEVICE, context->tx[0],
+			    SAHARA_RESET_LENGTH, MHI_EOT);
+	if (ret)
+		dev_err(&context->mhi_dev->dev, "Unable to send reset response %d\n", ret);
+}
+
+static void sahara_hello(struct sahara_context *context)
+{
+	int ret;
+
+	dev_dbg(&context->mhi_dev->dev,
+		"HELLO cmd received. length:%d version:%d version_compat:%d max_length:%d mode:%d\n",
+		le32_to_cpu(context->rx->length),
+		le32_to_cpu(context->rx->hello.version),
+		le32_to_cpu(context->rx->hello.version_compat),
+		le32_to_cpu(context->rx->hello.max_length),
+		le32_to_cpu(context->rx->hello.mode));
+
+	if (le32_to_cpu(context->rx->length) != SAHARA_HELLO_LENGTH) {
+		dev_err(&context->mhi_dev->dev, "Malformed hello packet - length %d\n",
+			le32_to_cpu(context->rx->length));
+		return;
+	}
+	if (le32_to_cpu(context->rx->hello.version) != SAHARA_VERSION) {
+		dev_err(&context->mhi_dev->dev, "Unsupported hello packet - version %d\n",
+			le32_to_cpu(context->rx->hello.version));
+		return;
+	}
+
+	if (le32_to_cpu(context->rx->hello.mode) != SAHARA_MODE_IMAGE_TX_PENDING &&
+	    le32_to_cpu(context->rx->hello.mode) != SAHARA_MODE_IMAGE_TX_COMPLETE) {
+		dev_err(&context->mhi_dev->dev, "Unsupported hello packet - mode %d\n",
+			le32_to_cpu(context->rx->hello.mode));
+		return;
+	}
+
+	context->tx[0]->cmd = cpu_to_le32(SAHARA_HELLO_RESP_CMD);
+	context->tx[0]->length = cpu_to_le32(SAHARA_HELLO_LENGTH);
+	context->tx[0]->hello_resp.version = cpu_to_le32(SAHARA_VERSION);
+	context->tx[0]->hello_resp.version_compat = cpu_to_le32(SAHARA_VERSION);
+	context->tx[0]->hello_resp.status = cpu_to_le32(SAHARA_SUCCESS);
+	context->tx[0]->hello_resp.mode = context->rx->hello_resp.mode;
+
+	ret = mhi_queue_buf(context->mhi_dev, DMA_TO_DEVICE, context->tx[0],
+			    SAHARA_HELLO_LENGTH, MHI_EOT);
+	if (ret)
+		dev_err(&context->mhi_dev->dev, "Unable to send hello response %d\n", ret);
+}
+
+static void sahara_read_data(struct sahara_context *context)
+{
+	u32 image_id, data_offset, data_len, pkt_data_len;
+	int ret;
+	int i;
+
+	dev_dbg(&context->mhi_dev->dev,
+		"READ_DATA cmd received. length:%d image:%d offset:%d data_length:%d\n",
+		le32_to_cpu(context->rx->length),
+		le32_to_cpu(context->rx->read_data.image),
+		le32_to_cpu(context->rx->read_data.offset),
+		le32_to_cpu(context->rx->read_data.length));
+
+	if (le32_to_cpu(context->rx->length) != SAHARA_READ_DATA_LENGTH) {
+		dev_err(&context->mhi_dev->dev, "Malformed read_data packet - length %d\n",
+			le32_to_cpu(context->rx->length));
+		return;
+	}
+
+	image_id = le32_to_cpu(context->rx->read_data.image);
+	data_offset = le32_to_cpu(context->rx->read_data.offset);
+	data_len = le32_to_cpu(context->rx->read_data.length);
+
+	ret = sahara_find_image(context, image_id);
+	if (ret) {
+		sahara_send_reset(context);
+		return;
+	}
+
+	/*
+	 * Image is released when the device is done with it via
+	 * SAHARA_END_OF_IMAGE_CMD. sahara_send_reset() will either cause the
+	 * device to retry the operation with a modification, or decide to be
+	 * done with the image and trigger SAHARA_END_OF_IMAGE_CMD.
+	 * release_image() is called from SAHARA_END_OF_IMAGE_CMD. processing
+	 * and is not needed here on error.
+	 */
+
+	if (data_len > SAHARA_TRANSFER_MAX_SIZE) {
+		dev_err(&context->mhi_dev->dev, "Malformed read_data packet - data len %d exceeds max xfer size %d\n",
+			data_len, SAHARA_TRANSFER_MAX_SIZE);
+		sahara_send_reset(context);
+		return;
+	}
+
+	if (data_offset >= context->firmware->size) {
+		dev_err(&context->mhi_dev->dev, "Malformed read_data packet - data offset %d exceeds file size %zu\n",
+			data_offset, context->firmware->size);
+		sahara_send_reset(context);
+		return;
+	}
+
+	if (size_add(data_offset, data_len) > context->firmware->size) {
+		dev_err(&context->mhi_dev->dev, "Malformed read_data packet - data offset %d and length %d exceeds file size %zu\n",
+			data_offset, data_len, context->firmware->size);
+		sahara_send_reset(context);
+		return;
+	}
+
+	for (i = 0; i < SAHARA_NUM_TX_BUF && data_len; ++i) {
+		pkt_data_len = min(data_len, SAHARA_PACKET_MAX_SIZE);
+
+		memcpy(context->tx[i], &context->firmware->data[data_offset], pkt_data_len);
+
+		data_offset += pkt_data_len;
+		data_len -= pkt_data_len;
+
+		ret = mhi_queue_buf(context->mhi_dev, DMA_TO_DEVICE,
+				    context->tx[i], pkt_data_len,
+				    !data_len ? MHI_EOT : MHI_CHAIN);
+		if (ret) {
+			dev_err(&context->mhi_dev->dev, "Unable to send read_data response %d\n",
+				ret);
+			return;
+		}
+	}
+}
+
+static void sahara_end_of_image(struct sahara_context *context)
+{
+	int ret;
+
+	dev_dbg(&context->mhi_dev->dev,
+		"END_OF_IMAGE cmd received. length:%d image:%d status:%d\n",
+		le32_to_cpu(context->rx->length),
+		le32_to_cpu(context->rx->end_of_image.image),
+		le32_to_cpu(context->rx->end_of_image.status));
+
+	if (le32_to_cpu(context->rx->length) != SAHARA_END_OF_IMAGE_LENGTH) {
+		dev_err(&context->mhi_dev->dev, "Malformed end_of_image packet - length %d\n",
+			le32_to_cpu(context->rx->length));
+		return;
+	}
+
+	if (context->active_image_id != SAHARA_IMAGE_ID_NONE &&
+	    le32_to_cpu(context->rx->end_of_image.image) != context->active_image_id) {
+		dev_err(&context->mhi_dev->dev, "Malformed end_of_image packet - image %d is not the active image\n",
+			le32_to_cpu(context->rx->end_of_image.image));
+		return;
+	}
+
+	sahara_release_image(context);
+
+	if (le32_to_cpu(context->rx->end_of_image.status))
+		return;
+
+	context->tx[0]->cmd = cpu_to_le32(SAHARA_DONE_CMD);
+	context->tx[0]->length = cpu_to_le32(SAHARA_DONE_LENGTH);
+
+	ret = mhi_queue_buf(context->mhi_dev, DMA_TO_DEVICE, context->tx[0],
+			    SAHARA_DONE_LENGTH, MHI_EOT);
+	if (ret)
+		dev_dbg(&context->mhi_dev->dev, "Unable to send done response %d\n", ret);
+}
+
+static void sahara_processing(struct work_struct *work)
+{
+	struct sahara_context *context = container_of(work, struct sahara_context, work);
+	int ret;
+
+	switch (le32_to_cpu(context->rx->cmd)) {
+	case SAHARA_HELLO_CMD:
+		sahara_hello(context);
+		break;
+	case SAHARA_READ_DATA_CMD:
+		sahara_read_data(context);
+		break;
+	case SAHARA_END_OF_IMAGE_CMD:
+		sahara_end_of_image(context);
+		break;
+	case SAHARA_DONE_RESP_CMD:
+		/* Intentional do nothing as we don't need to exit an app */
+		break;
+	default:
+		dev_err(&context->mhi_dev->dev, "Unknown command %d\n",
+			le32_to_cpu(context->rx->cmd));
+		break;
+	}
+
+	ret = mhi_queue_buf(context->mhi_dev, DMA_FROM_DEVICE, context->rx,
+			    SAHARA_PACKET_MAX_SIZE, MHI_EOT);
+	if (ret)
+		dev_err(&context->mhi_dev->dev, "Unable to requeue rx buf %d\n", ret);
+}
+
+static int sahara_mhi_probe(struct mhi_device *mhi_dev, const struct mhi_device_id *id)
+{
+	struct sahara_context *context;
+	int ret;
+	int i;
+
+	context = devm_kzalloc(&mhi_dev->dev, sizeof(*context), GFP_KERNEL);
+	if (!context)
+		return -ENOMEM;
+
+	context->rx = devm_kzalloc(&mhi_dev->dev, SAHARA_PACKET_MAX_SIZE, GFP_KERNEL);
+	if (!context->rx)
+		return -ENOMEM;
+
+	/*
+	 * AIC100 defines SAHARA_TRANSFER_MAX_SIZE as the largest value it
+	 * will request for READ_DATA. This is larger than
+	 * SAHARA_PACKET_MAX_SIZE, and we need 9x SAHARA_PACKET_MAX_SIZE to
+	 * cover SAHARA_TRANSFER_MAX_SIZE. When the remote side issues a
+	 * READ_DATA, it requires a transfer of the exact size requested. We
+	 * can use MHI_CHAIN to link multiple buffers into a single transfer
+	 * but the remote side will not consume the buffers until it sees an
+	 * EOT, thus we need to allocate enough buffers to put in the tx fifo
+	 * to cover an entire READ_DATA request of the max size.
+	 */
+	for (i = 0; i < SAHARA_NUM_TX_BUF; ++i) {
+		context->tx[i] = devm_kzalloc(&mhi_dev->dev, SAHARA_PACKET_MAX_SIZE, GFP_KERNEL);
+		if (!context->tx[i])
+			return -ENOMEM;
+	}
+
+	context->mhi_dev = mhi_dev;
+	INIT_WORK(&context->work, sahara_processing);
+	context->image_table = aic100_image_table;
+	context->table_size = ARRAY_SIZE(aic100_image_table);
+	context->active_image_id = SAHARA_IMAGE_ID_NONE;
+	dev_set_drvdata(&mhi_dev->dev, context);
+
+	ret = mhi_prepare_for_transfer(mhi_dev);
+	if (ret)
+		return ret;
+
+	ret = mhi_queue_buf(mhi_dev, DMA_FROM_DEVICE, context->rx, SAHARA_PACKET_MAX_SIZE, MHI_EOT);
+	if (ret) {
+		mhi_unprepare_from_transfer(mhi_dev);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void sahara_mhi_remove(struct mhi_device *mhi_dev)
+{
+	struct sahara_context *context = dev_get_drvdata(&mhi_dev->dev);
+
+	cancel_work_sync(&context->work);
+	sahara_release_image(context);
+	mhi_unprepare_from_transfer(mhi_dev);
+}
+
+static void sahara_mhi_ul_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result)
+{
+}
+
+static void sahara_mhi_dl_xfer_cb(struct mhi_device *mhi_dev, struct mhi_result *mhi_result)
+{
+	struct sahara_context *context = dev_get_drvdata(&mhi_dev->dev);
+
+	if (!mhi_result->transaction_status)
+		schedule_work(&context->work);
+}
+
+static const struct mhi_device_id sahara_mhi_match_table[] = {
+	{ .chan = "QAIC_SAHARA", },
+	{},
+};
+
+static struct mhi_driver sahara_mhi_driver = {
+	.id_table = sahara_mhi_match_table,
+	.remove = sahara_mhi_remove,
+	.probe = sahara_mhi_probe,
+	.ul_xfer_cb = sahara_mhi_ul_xfer_cb,
+	.dl_xfer_cb = sahara_mhi_dl_xfer_cb,
+	.driver = {
+		.name = "sahara",
+	},
+};
+
+int sahara_register(void)
+{
+	return mhi_driver_register(&sahara_mhi_driver);
+}
+
+void sahara_unregister(void)
+{
+	mhi_driver_unregister(&sahara_mhi_driver);
+}
diff --git a/drivers/accel/qaic/sahara.h b/drivers/accel/qaic/sahara.h
new file mode 100644
index 0000000000..640208acc0
--- /dev/null
+++ b/drivers/accel/qaic/sahara.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/* Copyright (c) 2024 Qualcomm Innovation Center, Inc. All rights reserved. */
+
+#ifndef __SAHARA_H__
+#define __SAHARA_H__
+
+int sahara_register(void);
+void sahara_unregister(void);
+#endif /* __SAHARA_H__ */