// SPDX-License-Identifier: GPL-2.0-only OR MIT
/* Copyright (c) 2023 Imagination Technologies Ltd. */

#include "pvr_device.h"
#include "pvr_rogue_fwif_stream.h"
#include "pvr_stream.h"

#include <linux/align.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <uapi/drm/pvr_drm.h>

static __always_inline bool
stream_def_is_supported(struct pvr_device *pvr_dev, const struct pvr_stream_def *stream_def)
{
	if (stream_def->feature == PVR_FEATURE_NONE)
		return true;

	if (!(stream_def->feature & PVR_FEATURE_NOT) &&
	    pvr_device_has_feature(pvr_dev, stream_def->feature)) {
		return true;
	}

	if ((stream_def->feature & PVR_FEATURE_NOT) &&
	    !pvr_device_has_feature(pvr_dev, stream_def->feature & ~PVR_FEATURE_NOT)) {
		return true;
	}

	return false;
}

static int
pvr_stream_get_data(u8 *stream, u32 *stream_offset, u32 stream_size, u32 data_size, u32 align_size,
		    void *dest)
{
	*stream_offset = ALIGN(*stream_offset, align_size);

	if ((*stream_offset + data_size) > stream_size)
		return -EINVAL;

	memcpy(dest, stream + *stream_offset, data_size);

	(*stream_offset) += data_size;

	return 0;
}

/**
 * pvr_stream_process_1() - Process a single stream and fill destination structure
 * @pvr_dev: Device pointer.
 * @stream_def: Stream definition.
 * @nr_entries: Number of entries in &stream_def.
 * @stream: Pointer to stream.
 * @stream_offset: Starting offset within stream.
 * @stream_size: Size of input stream, in bytes.
 * @dest: Pointer to destination structure.
 * @dest_size: Size of destination structure.
 * @stream_offset_out: Pointer to variable to write updated stream offset to. May be NULL.
 *
 * Returns:
 *  * 0 on success, or
 *  * -%EINVAL on malformed stream.
 */
static int
pvr_stream_process_1(struct pvr_device *pvr_dev, const struct pvr_stream_def *stream_def,
		     u32 nr_entries, u8 *stream, u32 stream_offset, u32 stream_size,
		     u8 *dest, u32 dest_size, u32 *stream_offset_out)
{
	int err = 0;

	for (u32 i = 0; i < nr_entries; i++) {
		if (stream_def[i].offset >= dest_size) {
			err = -EINVAL;
			break;
		}

		if (!stream_def_is_supported(pvr_dev, &stream_def[i]))
			continue;

		switch (stream_def[i].size) {
		case PVR_STREAM_SIZE_8:
			err = pvr_stream_get_data(stream, &stream_offset, stream_size, sizeof(u8),
						  sizeof(u8), dest + stream_def[i].offset);
			if (err)
				return err;
			break;

		case PVR_STREAM_SIZE_16:
			err = pvr_stream_get_data(stream, &stream_offset, stream_size, sizeof(u16),
						  sizeof(u16), dest + stream_def[i].offset);
			if (err)
				return err;
			break;

		case PVR_STREAM_SIZE_32:
			err = pvr_stream_get_data(stream, &stream_offset, stream_size, sizeof(u32),
						  sizeof(u32), dest + stream_def[i].offset);
			if (err)
				return err;
			break;

		case PVR_STREAM_SIZE_64:
			err = pvr_stream_get_data(stream, &stream_offset, stream_size, sizeof(u64),
						  sizeof(u64), dest + stream_def[i].offset);
			if (err)
				return err;
			break;

		case PVR_STREAM_SIZE_ARRAY:
			err = pvr_stream_get_data(stream, &stream_offset, stream_size,
						  stream_def[i].array_size, sizeof(u64),
						  dest + stream_def[i].offset);
			if (err)
				return err;
			break;
		}
	}

	if (stream_offset_out)
		*stream_offset_out = stream_offset;

	return err;
}

static int
pvr_stream_process_ext_stream(struct pvr_device *pvr_dev,
			      const struct pvr_stream_cmd_defs *cmd_defs, void *ext_stream,
			      u32 stream_offset, u32 ext_stream_size, void *dest)
{
	u32 musthave_masks[PVR_STREAM_EXTHDR_TYPE_MAX];
	u32 ext_header;
	int err = 0;

	/* Copy "must have" mask from device. We clear this as we process the stream. */
	memcpy(musthave_masks, pvr_dev->stream_musthave_quirks[cmd_defs->type],
	       sizeof(musthave_masks));

	do {
		const struct pvr_stream_ext_header *header;
		u32 type;
		u32 data;

		err = pvr_stream_get_data(ext_stream, &stream_offset, ext_stream_size, sizeof(u32),
					  sizeof(ext_header), &ext_header);
		if (err)
			return err;

		type = (ext_header & PVR_STREAM_EXTHDR_TYPE_MASK) >> PVR_STREAM_EXTHDR_TYPE_SHIFT;
		data = ext_header & PVR_STREAM_EXTHDR_DATA_MASK;

		if (type >= cmd_defs->ext_nr_headers)
			return -EINVAL;

		header = &cmd_defs->ext_headers[type];
		if (data & ~header->valid_mask)
			return -EINVAL;

		musthave_masks[type] &= ~data;

		for (u32 i = 0; i < header->ext_streams_num; i++) {
			const struct pvr_stream_ext_def *ext_def = &header->ext_streams[i];

			if (!(ext_header & ext_def->header_mask))
				continue;

			if (!pvr_device_has_uapi_quirk(pvr_dev, ext_def->quirk))
				return -EINVAL;

			err = pvr_stream_process_1(pvr_dev, ext_def->stream, ext_def->stream_len,
						   ext_stream, stream_offset,
						   ext_stream_size, dest,
						   cmd_defs->dest_size, &stream_offset);
			if (err)
				return err;
		}
	} while (ext_header & PVR_STREAM_EXTHDR_CONTINUATION);

	/*
	 * Verify that "must have" mask is now zero. If it isn't then one of the "must have" quirks
	 * for this command was not present.
	 */
	for (u32 i = 0; i < cmd_defs->ext_nr_headers; i++) {
		if (musthave_masks[i])
			return -EINVAL;
	}

	return 0;
}

/**
 * pvr_stream_process() - Build FW structure from stream
 * @pvr_dev: Device pointer.
 * @cmd_defs: Stream definition.
 * @stream: Pointer to command stream.
 * @stream_size: Size of command stream, in bytes.
 * @dest_out: Pointer to destination buffer.
 *
 * Caller is responsible for freeing the output structure.
 *
 * Returns:
 *  * 0 on success,
 *  * -%ENOMEM on out of memory, or
 *  * -%EINVAL on malformed stream.
 */
int
pvr_stream_process(struct pvr_device *pvr_dev, const struct pvr_stream_cmd_defs *cmd_defs,
		   void *stream, u32 stream_size, void *dest_out)
{
	u32 stream_offset = 0;
	u32 main_stream_len;
	u32 padding;
	int err;

	if (!stream || !stream_size)
		return -EINVAL;

	err = pvr_stream_get_data(stream, &stream_offset, stream_size, sizeof(u32),
				  sizeof(u32), &main_stream_len);
	if (err)
		return err;

	/*
	 * u32 after stream length is padding to ensure u64 alignment, but may be used for expansion
	 * in the future. Verify it's zero.
	 */
	err = pvr_stream_get_data(stream, &stream_offset, stream_size, sizeof(u32),
				  sizeof(u32), &padding);
	if (err)
		return err;

	if (main_stream_len < stream_offset || main_stream_len > stream_size || padding)
		return -EINVAL;

	err = pvr_stream_process_1(pvr_dev, cmd_defs->main_stream, cmd_defs->main_stream_len,
				   stream, stream_offset, main_stream_len, dest_out,
				   cmd_defs->dest_size, &stream_offset);
	if (err)
		return err;

	if (stream_offset < stream_size) {
		err = pvr_stream_process_ext_stream(pvr_dev, cmd_defs, stream, stream_offset,
						    stream_size, dest_out);
		if (err)
			return err;
	} else {
		/*
		 * If we don't have an extension stream then there must not be any "must have"
		 * quirks for this command.
		 */
		for (u32 i = 0; i < cmd_defs->ext_nr_headers; i++) {
			if (pvr_dev->stream_musthave_quirks[cmd_defs->type][i])
				return -EINVAL;
		}
	}

	return 0;
}

/**
 * pvr_stream_create_musthave_masks() - Create "must have" masks for streams based on current device
 *                                      quirks
 * @pvr_dev: Device pointer.
 */
void
pvr_stream_create_musthave_masks(struct pvr_device *pvr_dev)
{
	memset(pvr_dev->stream_musthave_quirks, 0, sizeof(pvr_dev->stream_musthave_quirks));

	if (pvr_device_has_uapi_quirk(pvr_dev, 47217))
		pvr_dev->stream_musthave_quirks[PVR_STREAM_TYPE_FRAG][0] |=
			PVR_STREAM_EXTHDR_FRAG0_BRN47217;

	if (pvr_device_has_uapi_quirk(pvr_dev, 49927)) {
		pvr_dev->stream_musthave_quirks[PVR_STREAM_TYPE_GEOM][0] |=
			PVR_STREAM_EXTHDR_GEOM0_BRN49927;
		pvr_dev->stream_musthave_quirks[PVR_STREAM_TYPE_FRAG][0] |=
			PVR_STREAM_EXTHDR_FRAG0_BRN49927;
		pvr_dev->stream_musthave_quirks[PVR_STREAM_TYPE_COMPUTE][0] |=
			PVR_STREAM_EXTHDR_COMPUTE0_BRN49927;
	}
}