wmi_tlv_helper.c

/*
 * Copyright (c) 2013-2017 The Linux Foundation. All rights reserved.
 *
 * Previously licensed under the ISC license by Qualcomm Atheros, Inc.
 *
 *
 * Permission to use, copy, modify, and/or distribute this software for
 * any purpose with or without fee is hereby granted, provided that the
 * above copyright notice and this permission notice appear in all
 * copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
 * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/*
 * This file was originally distributed by Qualcomm Atheros, Inc.
 * under proprietary terms before Copyright ownership was assigned
 * to the Linux Foundation.
 */

#include "wmi_tlv_platform.c"
#include "wmi_tlv_defs.h"
#include "wmi_version.h"

#define WMITLV_GET_ATTRIB_NUM_TLVS  0xFFFFFFFF

#define WMITLV_GET_CMDID(val) (val & 0x00FFFFFF)
#define WMITLV_GET_NUM_TLVS(val) ((val >> 24) & 0xFF)

#define WMITLV_GET_TAGID(val) (val & 0x00000FFF)
#define WMITLV_GET_TAG_STRUCT_SIZE(val) ((val >> 12) & 0x000001FF)
#define WMITLV_GET_TAG_ARRAY_SIZE(val) ((val >> 21) & 0x000001FF)
#define WMITLV_GET_TAG_VARIED(val) ((val >> 30) & 0x00000001)

#define WMITLV_SET_ATTRB0(id) ((WMITLV_GET_TAG_NUM_TLV_ATTRIB(id) << 24) | \
				(id & 0x00FFFFFF))
#define WMITLV_SET_ATTRB1(tagID, tagStructSize, tagArraySize, tagVaried) \
	(((tagVaried&0x1)<<30) | ((tagArraySize&0x1FF)<<21) | \
	((tagStructSize&0x1FF)<<12) | (tagID&0xFFF))

#define WMITLV_OP_SET_TLV_ATTRIB_macro(param_ptr, param_len, wmi_cmd_event_id, \
	elem_tlv_tag, elem_struc_type, elem_name, var_len, arr_size)  \
	WMITLV_SET_ATTRB1(elem_tlv_tag, sizeof(elem_struc_type), arr_size, var_len),

#define WMITLV_GET_CMD_EVT_ATTRB_LIST(id) \
	WMITLV_SET_ATTRB0(id), \
	WMITLV_TABLE(id,SET_TLV_ATTRIB, NULL, 0)

A_UINT32 cmd_attr_list[] = {
	WMITLV_ALL_CMD_LIST(WMITLV_GET_CMD_EVT_ATTRB_LIST)
};

A_UINT32 evt_attr_list[] = {
	WMITLV_ALL_EVT_LIST(WMITLV_GET_CMD_EVT_ATTRB_LIST)
};

#ifdef NO_DYNAMIC_MEM_ALLOC
static wmitlv_cmd_param_info *g_wmi_static_cmd_param_info_buf;
A_UINT32 g_wmi_static_max_cmd_param_tlvs;
#endif


/**
 * wmitlv_set_static_param_tlv_buf() - tlv helper function
 * @param_tlv_buf: tlv buffer parameter
 * @max_tlvs_accomodated: max no of tlv entries
 *
 *
 * WMI TLV Helper function to set the static cmd_param_tlv structure
 * and number of TLVs that can be accomodated in the structure.
 * This function should be used when dynamic memory allocation is not
 * supported. When dynamic memory allocation is not supported by any
 * component then NO_DYNAMIC_MEMALLOC macro has to be defined in respective
 * tlv_platform.c file. And respective component has to allocate
 * cmd_param_tlv structure buffer to accomodate whatever number of TLV's.
 * Both the buffer address and number of TLV's that can be accomodated in
 * the buffer should be sent as arguments to this function.
 *
 * Return None
 */
void
wmitlv_set_static_param_tlv_buf(void *param_tlv_buf,
				A_UINT32 max_tlvs_accomodated)
{
#ifdef NO_DYNAMIC_MEM_ALLOC
	g_wmi_static_cmd_param_info_buf = param_tlv_buf;
	g_wmi_static_max_cmd_param_tlvs = max_tlvs_accomodated;
#endif
}

/**
 * wmitlv_get_attributes() - tlv helper function
 * @is_cmd_id: boolean for command attribute
 * @cmd_event_id: command event id
 * @curr_tlv_order: tlv order
 * @tlv_attr_ptr: pointer to tlv attribute
 *
 *
 * WMI TLV Helper functions to find the attributes of the
 * Command/Event TLVs.
 *
 * Return: 0 if success. Return >=1 if failure.
 */
static
A_UINT32 wmitlv_get_attributes(A_UINT32 is_cmd_id, A_UINT32 cmd_event_id,
			       A_UINT32 curr_tlv_order,
			       wmitlv_attributes_struc *tlv_attr_ptr)
{
	A_UINT32 i, base_index, num_tlvs, num_entries;
	A_UINT32 *pAttrArrayList;

	if (is_cmd_id) {
		pAttrArrayList = &cmd_attr_list[0];
		num_entries = QDF_ARRAY_SIZE(cmd_attr_list);
	} else {
		pAttrArrayList = &evt_attr_list[0];
		num_entries = QDF_ARRAY_SIZE(evt_attr_list);
	}

	for (i = 0; i < num_entries; i++) {
		num_tlvs = WMITLV_GET_NUM_TLVS(pAttrArrayList[i]);
		if (WMITLV_GET_CMDID(cmd_event_id) ==
		    WMITLV_GET_CMDID(pAttrArrayList[i])) {
			tlv_attr_ptr->cmd_num_tlv = num_tlvs;
			/* Return success from here when only number of TLVS for
			 * this command/event is required */
			if (curr_tlv_order == WMITLV_GET_ATTRIB_NUM_TLVS) {
				wmi_tlv_print_verbose
					("%s: WMI TLV attribute definitions for %s:0x%x found; num_of_tlvs:%d\n",
					__func__, (is_cmd_id ? "Cmd" : "Evt"),
					cmd_event_id, num_tlvs);
				return 0;
			}

			/* Return failure if tlv_order is more than the expected
			 * number of TLVs */
			if (curr_tlv_order >= num_tlvs) {
				wmi_tlv_print_error
					("%s: ERROR: TLV order %d greater than num_of_tlvs:%d for %s:0x%x\n",
					__func__, curr_tlv_order, num_tlvs,
					(is_cmd_id ? "Cmd" : "Evt"), cmd_event_id);
				return 1;
			}

			base_index = i + 1;     /* index to first TLV attributes */
			wmi_tlv_print_verbose
				("%s: WMI TLV attributes for %s:0x%x tlv[%d]:0x%x\n",
				__func__, (is_cmd_id ? "Cmd" : "Evt"),
				cmd_event_id, curr_tlv_order,
				pAttrArrayList[(base_index + curr_tlv_order)]);
			tlv_attr_ptr->tag_order = curr_tlv_order;
			tlv_attr_ptr->tag_id =
				WMITLV_GET_TAGID(pAttrArrayList
						 [(base_index + curr_tlv_order)]);
			tlv_attr_ptr->tag_struct_size =
				WMITLV_GET_TAG_STRUCT_SIZE(pAttrArrayList
							   [(base_index +
							     curr_tlv_order)]);
			tlv_attr_ptr->tag_varied_size =
				WMITLV_GET_TAG_VARIED(pAttrArrayList
						      [(base_index +
							curr_tlv_order)]);
			tlv_attr_ptr->tag_array_size =
				WMITLV_GET_TAG_ARRAY_SIZE(pAttrArrayList
							  [(base_index +
							    curr_tlv_order)]);
			return 0;
		}
		i += num_tlvs;
	}

	wmi_tlv_print_error
		("%s: ERROR: Didn't found WMI TLV attribute definitions for %s:0x%x\n",
		__func__, (is_cmd_id ? "Cmd" : "Evt"), cmd_event_id);
	return 1;
}

/**
 * wmitlv_check_tlv_params() - tlv helper function
 * @os_handle: os context handle
 * @param_struc_ptr: pointer to tlv structure
 * @is_cmd_id: boolean for command attribute
 * @wmi_cmd_event_id: command event id
 *
 *
 * Helper Function to vaidate the prepared TLV's for
 * an WMI event/command to be sent.
 *
 * Return: 0 if success. Return < 0 if failure.
 */
static int
wmitlv_check_tlv_params(void *os_handle, void *param_struc_ptr,
			A_UINT32 param_buf_len, A_UINT32 is_cmd_id,
			A_UINT32 wmi_cmd_event_id)
{
	wmitlv_attributes_struc attr_struct_ptr;
	A_UINT32 buf_idx = 0;
	A_UINT32 tlv_index = 0;
	A_UINT8 *buf_ptr = (unsigned char *)param_struc_ptr;
	A_UINT32 expected_num_tlvs, expected_tlv_len;
	A_INT32 error = -1;

	/* Get the number of TLVs for this command/event */
	if (wmitlv_get_attributes
		    (is_cmd_id, wmi_cmd_event_id, WMITLV_GET_ATTRIB_NUM_TLVS,
		    &attr_struct_ptr) != 0) {
		wmi_tlv_print_error
			("%s: ERROR: Couldn't get expected number of TLVs for Cmd=%d\n",
			__func__, wmi_cmd_event_id);
		goto Error_wmitlv_check_tlv_params;
	}

	/* NOTE: the returned number of TLVs is in "attr_struct_ptr.cmd_num_tlv" */

	expected_num_tlvs = attr_struct_ptr.cmd_num_tlv;

	while ((buf_idx + WMI_TLV_HDR_SIZE) <= param_buf_len) {
		A_UINT32 curr_tlv_tag =
			WMITLV_GET_TLVTAG(WMITLV_GET_HDR(buf_ptr));
		A_UINT32 curr_tlv_len =
			WMITLV_GET_TLVLEN(WMITLV_GET_HDR(buf_ptr));

		if ((buf_idx + WMI_TLV_HDR_SIZE + curr_tlv_len) > param_buf_len) {
			wmi_tlv_print_error
				("%s: ERROR: Invalid TLV length for Cmd=%d Tag_order=%d buf_idx=%d Tag:%d Len:%d TotalLen:%d\n",
				__func__, wmi_cmd_event_id, tlv_index, buf_idx,
				curr_tlv_tag, curr_tlv_len, param_buf_len);
			goto Error_wmitlv_check_tlv_params;
		}

		/* Get the attributes of the TLV with the given order in "tlv_index" */
		wmi_tlv_OS_MEMZERO(&attr_struct_ptr,
				   sizeof(wmitlv_attributes_struc));
		if (wmitlv_get_attributes
			    (is_cmd_id, wmi_cmd_event_id, tlv_index,
			    &attr_struct_ptr) != 0) {
			wmi_tlv_print_error
				("%s: ERROR: No TLV attributes found for Cmd=%d Tag_order=%d\n",
				__func__, wmi_cmd_event_id, tlv_index);
			goto Error_wmitlv_check_tlv_params;
		}

		/* Found the TLV that we wanted */
		wmi_tlv_print_verbose("%s: [tlv %d]: tag=%d, len=%d\n",
				      __func__, tlv_index, curr_tlv_tag,
				      curr_tlv_len);

		/* Validating Tag ID order */
		if (curr_tlv_tag != attr_struct_ptr.tag_id) {
			wmi_tlv_print_error
				("%s: ERROR: TLV has wrong tag in order for Cmd=0x%x. Given=%d, Expected=%d.\n",
				__func__, wmi_cmd_event_id, curr_tlv_tag,
				attr_struct_ptr.tag_id);
			goto Error_wmitlv_check_tlv_params;
		}

		/* Validate Tag length */
		/* Array TLVs length checking needs special handling */
		if ((curr_tlv_tag >= WMITLV_TAG_FIRST_ARRAY_ENUM)
		    && (curr_tlv_tag <= WMITLV_TAG_LAST_ARRAY_ENUM)) {
			if (attr_struct_ptr.tag_varied_size == WMITLV_SIZE_FIX) {
				/* Array size can't be invalid for fixed size Array TLV */
				if (WMITLV_ARR_SIZE_INVALID ==
				    attr_struct_ptr.tag_array_size) {
					wmi_tlv_print_error
						("%s: ERROR: array_size can't be invalid for Array TLV Cmd=0x%x Tag=%d\n",
						__func__, wmi_cmd_event_id,
						curr_tlv_tag);
					goto Error_wmitlv_check_tlv_params;
				}

				expected_tlv_len =
					attr_struct_ptr.tag_array_size *
					attr_struct_ptr.tag_struct_size;
				/* Paddding is only required for Byte array Tlvs all other
				 * array tlv's should be aligned to 4 bytes during their
				 * definition */
				if (WMITLV_TAG_ARRAY_BYTE ==
				    attr_struct_ptr.tag_id) {
					expected_tlv_len =
						roundup(expected_tlv_len,
							sizeof(A_UINT32));
				}

				if (curr_tlv_len != expected_tlv_len) {
					wmi_tlv_print_error
						("%s: ERROR: TLV has wrong length for Cmd=0x%x. Tag_order=%d  Tag=%d, Given_Len:%d Expected_Len=%d.\n",
						__func__, wmi_cmd_event_id,
						tlv_index, curr_tlv_tag,
						curr_tlv_len, expected_tlv_len);
					goto Error_wmitlv_check_tlv_params;
				}
			} else {
				/* Array size should be invalid for variable size Array TLV */
				if (WMITLV_ARR_SIZE_INVALID !=
				    attr_struct_ptr.tag_array_size) {
					wmi_tlv_print_error
						("%s: ERROR: array_size should be invalid for Array TLV Cmd=0x%x Tag=%d\n",
						__func__, wmi_cmd_event_id,
						curr_tlv_tag);
					goto Error_wmitlv_check_tlv_params;
				}

				/* Incase of variable length TLV's, there is no expectation
				 * on the length field so do whatever checking you can
				 * depending on the TLV tag if TLV length is non-zero */
				if (curr_tlv_len != 0) {
					/* Verify TLV length is aligned to the size of structure */
					if ((curr_tlv_len %
					     attr_struct_ptr.tag_struct_size) !=
					    0) {
						wmi_tlv_print_error
							("%s: ERROR: TLV length %d for Cmd=0x%x is not aligned to size of structure(%d bytes)\n",
							__func__, curr_tlv_len,
							wmi_cmd_event_id,
							attr_struct_ptr.
							tag_struct_size);
						goto Error_wmitlv_check_tlv_params;
					}

					if (curr_tlv_tag ==
					    WMITLV_TAG_ARRAY_STRUC) {
						A_UINT8 *tlv_buf_ptr = NULL;
						A_UINT32 in_tlv_len;
						A_UINT32 idx;
						A_UINT32 num_of_elems;

						/* Verify length of inner TLVs */

						num_of_elems =
							curr_tlv_len /
							attr_struct_ptr.
							tag_struct_size;
						/* Set tlv_buf_ptr to the first inner TLV address */
						tlv_buf_ptr =
							buf_ptr + WMI_TLV_HDR_SIZE;
						for (idx = 0;
						     idx < num_of_elems;
						     idx++) {
							in_tlv_len =
								WMITLV_GET_TLVLEN
									(WMITLV_GET_HDR
										(tlv_buf_ptr));
							if ((in_tlv_len +
							     WMI_TLV_HDR_SIZE)
							    !=
							    attr_struct_ptr.
							    tag_struct_size) {
								wmi_tlv_print_error
									("%s: ERROR: TLV has wrong length for Cmd=0x%x. Tag_order=%d  Tag=%d, Given_Len:%zu Expected_Len=%d.\n",
									__func__,
									wmi_cmd_event_id,
									tlv_index,
									curr_tlv_tag,
									(in_tlv_len
									 +
									 WMI_TLV_HDR_SIZE),
									attr_struct_ptr.
									tag_struct_size);
								goto Error_wmitlv_check_tlv_params;
							}
							tlv_buf_ptr +=
								in_tlv_len +
								WMI_TLV_HDR_SIZE;
						}
					} else
					if ((curr_tlv_tag ==
					     WMITLV_TAG_ARRAY_UINT32)
					    || (curr_tlv_tag ==
						WMITLV_TAG_ARRAY_BYTE)
					    || (curr_tlv_tag ==
						WMITLV_TAG_ARRAY_FIXED_STRUC)) {
						/* Nothing to verify here */
					} else {
						wmi_tlv_print_error
							("%s ERROR Need to handle the Array tlv %d for variable length for Cmd=0x%x\n",
							__func__,
							attr_struct_ptr.tag_id,
							wmi_cmd_event_id);
						goto Error_wmitlv_check_tlv_params;
					}
				}
			}
		} else {
			/* Non-array TLV. */

			if ((curr_tlv_len + WMI_TLV_HDR_SIZE) !=
			    attr_struct_ptr.tag_struct_size) {
				wmi_tlv_print_error
					("%s: ERROR: TLV has wrong length for Cmd=0x%x. Given=%zu, Expected=%d.\n",
					__func__, wmi_cmd_event_id,
					(curr_tlv_len + WMI_TLV_HDR_SIZE),
					attr_struct_ptr.tag_struct_size);
				goto Error_wmitlv_check_tlv_params;
			}
		}

		/* Check TLV length is aligned to 4 bytes or not */
		if ((curr_tlv_len % sizeof(A_UINT32)) != 0) {
			wmi_tlv_print_error
				("%s: ERROR: TLV length %d for Cmd=0x%x is not aligned to %zu bytes\n",
				__func__, curr_tlv_len, wmi_cmd_event_id,
				sizeof(A_UINT32));
			goto Error_wmitlv_check_tlv_params;
		}

		tlv_index++;
		buf_ptr += curr_tlv_len + WMI_TLV_HDR_SIZE;
		buf_idx += curr_tlv_len + WMI_TLV_HDR_SIZE;
	}

	if (tlv_index != expected_num_tlvs) {
		wmi_tlv_print_verbose
			("%s: INFO: Less number of TLVs filled for Cmd=0x%x Filled %d Expected=%d\n",
			__func__, wmi_cmd_event_id, tlv_index, expected_num_tlvs);
	}

	return 0;
Error_wmitlv_check_tlv_params:
	return error;
}

/**
 * wmitlv_check_event_tlv_params() - tlv helper function
 * @os_handle: os context handle
 * @param_struc_ptr: pointer to tlv structure
 * @is_cmd_id: boolean for command attribute
 * @wmi_cmd_event_id: command event id
 *
 *
 * Helper Function to vaidate the prepared TLV's for
 * an WMI event/command to be sent.
 *
 * Return: 0 if success. Return < 0 if failure.
 */
int
wmitlv_check_event_tlv_params(void *os_handle, void *param_struc_ptr,
			      A_UINT32 param_buf_len, A_UINT32 wmi_cmd_event_id)
{
	A_UINT32 is_cmd_id = 0;

	return wmitlv_check_tlv_params
			(os_handle, param_struc_ptr, param_buf_len, is_cmd_id,
			wmi_cmd_event_id);
}

/**
 * wmitlv_check_command_tlv_params() - tlv helper function
 * @os_handle: os context handle
 * @param_struc_ptr: pointer to tlv structure
 * @is_cmd_id: boolean for command attribute
 * @wmi_cmd_event_id: command event id
 *
 *
 * Helper Function to vaidate the prepared TLV's for
 * an WMI event/command to be sent.
 *
 * Return: 0 if success. Return < 0 if failure.
 */
int
wmitlv_check_command_tlv_params(void *os_handle, void *param_struc_ptr,
				A_UINT32 param_buf_len,
				A_UINT32 wmi_cmd_event_id)
{
	A_UINT32 is_cmd_id = 1;

	return wmitlv_check_tlv_params
			(os_handle, param_struc_ptr, param_buf_len, is_cmd_id,
			wmi_cmd_event_id);
}

/**
 * wmitlv_check_and_pad_tlvs() - tlv helper function
 * @os_handle: os context handle
 * @param_buf_len: length of tlv parameter
 * @param_struc_ptr: pointer to tlv structure
 * @is_cmd_id: boolean for command attribute
 * @wmi_cmd_event_id: command event id
 * @wmi_cmd_struct_ptr: wmi command structure
 *
 *
 * vaidate the TLV's coming for an event/command and
 * also pads data to TLV's if necessary
 *
 * Return: 0 if success. Return < 0 if failure.
 */
static int
wmitlv_check_and_pad_tlvs(void *os_handle, void *param_struc_ptr,
			  A_UINT32 param_buf_len, A_UINT32 is_cmd_id,
			  A_UINT32 wmi_cmd_event_id, void **wmi_cmd_struct_ptr)
{
	wmitlv_attributes_struc attr_struct_ptr;
	A_UINT32 buf_idx = 0;
	A_UINT32 tlv_index = 0;
	A_UINT32 num_of_elems = 0;
	int tlv_size_diff = 0;
	A_UINT8 *buf_ptr = (unsigned char *)param_struc_ptr;
	wmitlv_cmd_param_info *cmd_param_tlvs_ptr = NULL;
	A_UINT32 remaining_expected_tlvs = 0xFFFFFFFF;
	A_UINT32 len_wmi_cmd_struct_buf;
	A_INT32 error = -1;

	/* Get the number of TLVs for this command/event */
	if (wmitlv_get_attributes
		    (is_cmd_id, wmi_cmd_event_id, WMITLV_GET_ATTRIB_NUM_TLVS,
		    &attr_struct_ptr) != 0) {
		wmi_tlv_print_error
			("%s: ERROR: Couldn't get expected number of TLVs for Cmd=%d\n",
			__func__, wmi_cmd_event_id);
		return error;
	}
	/* NOTE: the returned number of TLVs is in "attr_struct_ptr.cmd_num_tlv" */

	if (param_buf_len < WMI_TLV_HDR_SIZE) {
		wmi_tlv_print_error
			("%s: ERROR: Incorrect param buf length passed\n",
			__func__);
		return error;
	}

	/* Create base structure of format wmi_cmd_event_id##_param_tlvs */
	len_wmi_cmd_struct_buf =
		attr_struct_ptr.cmd_num_tlv * sizeof(wmitlv_cmd_param_info);
#ifndef NO_DYNAMIC_MEM_ALLOC
	/* Dynamic memory allocation supported */
	wmi_tlv_os_mem_alloc(os_handle, *wmi_cmd_struct_ptr,
			     len_wmi_cmd_struct_buf);
#else
	/* Dynamic memory allocation is not supported. Use the buffer
	 * g_wmi_static_cmd_param_info_buf, which should be set using
	 * wmi_tlv_set_static_param_tlv_buf(),
	 * for base structure of format wmi_cmd_event_id##_param_tlvs */
	*wmi_cmd_struct_ptr = g_wmi_static_cmd_param_info_buf;
	if (attr_struct_ptr.cmd_num_tlv > g_wmi_static_max_cmd_param_tlvs) {
		/* Error: Expecting more TLVs that accomodated for static structure  */
		wmi_tlv_print_error
			("%s: Error: Expecting more TLVs that accomodated for static structure. Expected:%d Accomodated:%d\n",
			__func__, attr_struct_ptr.cmd_num_tlv,
			g_wmi_static_max_cmd_param_tlvs);
		return error;
	}
#endif
	if (*wmi_cmd_struct_ptr == NULL) {
		/* Error: unable to alloc memory */
		wmi_tlv_print_error
			("%s: Error: unable to alloc memory (size=%d) for TLV\n",
			__func__, len_wmi_cmd_struct_buf);
		return error;
	}

	cmd_param_tlvs_ptr = (wmitlv_cmd_param_info *) *wmi_cmd_struct_ptr;
	wmi_tlv_OS_MEMZERO(cmd_param_tlvs_ptr, len_wmi_cmd_struct_buf);
	remaining_expected_tlvs = attr_struct_ptr.cmd_num_tlv;

	while (((buf_idx + WMI_TLV_HDR_SIZE) <= param_buf_len)
	       && (remaining_expected_tlvs)) {
		A_UINT32 curr_tlv_tag =
			WMITLV_GET_TLVTAG(WMITLV_GET_HDR(buf_ptr));
		A_UINT32 curr_tlv_len =
			WMITLV_GET_TLVLEN(WMITLV_GET_HDR(buf_ptr));
		int num_padding_bytes = 0;

		/* Get the attributes of the TLV with the given order in "tlv_index" */
		wmi_tlv_OS_MEMZERO(&attr_struct_ptr,
				   sizeof(wmitlv_attributes_struc));
		if (wmitlv_get_attributes
			    (is_cmd_id, wmi_cmd_event_id, tlv_index,
			    &attr_struct_ptr) != 0) {
			wmi_tlv_print_error
				("%s: ERROR: No TLV attributes found for Cmd=%d Tag_order=%d\n",
				__func__, wmi_cmd_event_id, tlv_index);
			goto Error_wmitlv_check_and_pad_tlvs;
		}

		/* Found the TLV that we wanted */
		wmi_tlv_print_verbose("%s: [tlv %d]: tag=%d, len=%d\n",
				      __func__, tlv_index, curr_tlv_tag,
				      curr_tlv_len);

		/* Validating Tag order */
		if (curr_tlv_tag != attr_struct_ptr.tag_id) {
			wmi_tlv_print_error
				("%s: ERROR: TLV has wrong tag in order for Cmd=0x%x. Given=%d, Expected=%d.\n",
				__func__, wmi_cmd_event_id, curr_tlv_tag,
				attr_struct_ptr.tag_id);
			goto Error_wmitlv_check_and_pad_tlvs;
		}

		if ((curr_tlv_tag >= WMITLV_TAG_FIRST_ARRAY_ENUM)
		    && (curr_tlv_tag <= WMITLV_TAG_LAST_ARRAY_ENUM)) {
			/* Current Tag is an array of some kind. */
			/* Skip the TLV header of this array */
			buf_ptr += WMI_TLV_HDR_SIZE;
			buf_idx += WMI_TLV_HDR_SIZE;
		} else {
			/* Non-array TLV. */
			curr_tlv_len += WMI_TLV_HDR_SIZE;
		}

		if (attr_struct_ptr.tag_varied_size == WMITLV_SIZE_FIX) {
			/* This TLV is fixed length */
			if (WMITLV_ARR_SIZE_INVALID ==
			    attr_struct_ptr.tag_array_size) {
				tlv_size_diff =
					curr_tlv_len -
					attr_struct_ptr.tag_struct_size;
				num_of_elems =
					(curr_tlv_len > WMI_TLV_HDR_SIZE) ? 1 : 0;
			} else {
				tlv_size_diff =
					curr_tlv_len -
					(attr_struct_ptr.tag_struct_size *
					 attr_struct_ptr.tag_array_size);
				num_of_elems = attr_struct_ptr.tag_array_size;
			}
		} else {
			/* This TLV has a variable number of elements */
			if (WMITLV_TAG_ARRAY_STRUC == attr_struct_ptr.tag_id) {
				A_UINT32 in_tlv_len = 0;

				if (curr_tlv_len != 0) {
					in_tlv_len =
						WMITLV_GET_TLVLEN(WMITLV_GET_HDR
									  (buf_ptr));
					in_tlv_len += WMI_TLV_HDR_SIZE;
					tlv_size_diff =
						in_tlv_len -
						attr_struct_ptr.tag_struct_size;
					num_of_elems =
						curr_tlv_len / in_tlv_len;
					wmi_tlv_print_verbose
						("%s: WARN: TLV array of structures in_tlv_len=%d struct_size:%d diff:%d num_of_elems=%d \n",
						__func__, in_tlv_len,
						attr_struct_ptr.tag_struct_size,
						tlv_size_diff, num_of_elems);
				} else {
					tlv_size_diff = 0;
					num_of_elems = 0;
				}
			} else
			if ((WMITLV_TAG_ARRAY_UINT32 ==
			     attr_struct_ptr.tag_id)
			    || (WMITLV_TAG_ARRAY_BYTE ==
				attr_struct_ptr.tag_id)
			    || (WMITLV_TAG_ARRAY_FIXED_STRUC ==
				attr_struct_ptr.tag_id)) {
				tlv_size_diff = 0;
				num_of_elems =
					curr_tlv_len /
					attr_struct_ptr.tag_struct_size;
			} else {
				wmi_tlv_print_error
					("%s ERROR Need to handle this tag ID for variable length %d\n",
					__func__, attr_struct_ptr.tag_id);
				goto Error_wmitlv_check_and_pad_tlvs;
			}
		}

		if ((WMITLV_TAG_ARRAY_STRUC == attr_struct_ptr.tag_id) &&
		    (tlv_size_diff != 0)) {
			void *new_tlv_buf = NULL;
			A_UINT8 *tlv_buf_ptr = NULL;
			A_UINT32 in_tlv_len;
			A_UINT32 i;

			if (attr_struct_ptr.tag_varied_size == WMITLV_SIZE_FIX) {
				/* This is not allowed. The tag WMITLV_TAG_ARRAY_STRUC can
				 * only be used with variable-length structure array
				 * should not have a fixed number of elements (contradicting).
				 * Use WMITLV_TAG_ARRAY_FIXED_STRUC tag for fixed size
				 * structure array(where structure never change without
				 * breaking compatibility) */
				wmi_tlv_print_error
					("%s: ERROR: TLV (tag=%d) should be variable-length and not fixed length\n",
					__func__, curr_tlv_tag);
				goto Error_wmitlv_check_and_pad_tlvs;
			}

			/* Warning: Needs to allocate a larger structure and pad with zeros */
			wmi_tlv_print_verbose
				("%s: WARN: TLV array of structures needs padding. tlv_size_diff=%d\n",
				__func__, tlv_size_diff);

			/* incoming structure length */
			in_tlv_len =
				WMITLV_GET_TLVLEN(WMITLV_GET_HDR(buf_ptr)) +
				WMI_TLV_HDR_SIZE;
#ifndef NO_DYNAMIC_MEM_ALLOC
			wmi_tlv_os_mem_alloc(os_handle, new_tlv_buf,
					     (num_of_elems *
					      attr_struct_ptr.tag_struct_size));
			if (new_tlv_buf == NULL) {
				/* Error: unable to alloc memory */
				wmi_tlv_print_error
					("%s: Error: unable to alloc memory (size=%d) for padding the TLV array %d\n",
					__func__,
					(num_of_elems *
					 attr_struct_ptr.tag_struct_size),
					curr_tlv_tag);
				goto Error_wmitlv_check_and_pad_tlvs;
			}

			wmi_tlv_OS_MEMZERO(new_tlv_buf,
					   (num_of_elems *
					    attr_struct_ptr.tag_struct_size));
			tlv_buf_ptr = (A_UINT8 *) new_tlv_buf;
			for (i = 0; i < num_of_elems; i++) {
				if (tlv_size_diff > 0) {
					/* Incoming structure size is greater than expected
					 * structure size. so copy the number of bytes equal
					 * to expected structure size */
					wmi_tlv_OS_MEMCPY(tlv_buf_ptr,
							  (void *)(buf_ptr +
								   i *
								   in_tlv_len),
							  attr_struct_ptr.
							  tag_struct_size);
				} else {
					/* Incoming structure size is smaller than expected
					 * structure size. so copy the number of bytes equal
					 * to incoming structure size */
					wmi_tlv_OS_MEMCPY(tlv_buf_ptr,
							  (void *)(buf_ptr +
								   i *
								   in_tlv_len),
							  in_tlv_len);
				}
				tlv_buf_ptr += attr_struct_ptr.tag_struct_size;
			}
#else
			{
				A_UINT8 *src_addr;
				A_UINT8 *dst_addr;
				A_UINT32 buf_mov_len;

				if (tlv_size_diff < 0) {
					/* Incoming structure size is smaller than expected size
					 * then this needs padding for each element in the array */

					/* Find amount of bytes to be padded for one element */
					num_padding_bytes = tlv_size_diff * -1;

					/* Move subsequent TLVs by number of bytes to be padded
					 * for all elements */
					if (param_buf_len >
					    (buf_idx + curr_tlv_len)) {
						src_addr =
							buf_ptr + curr_tlv_len;
						dst_addr =
							buf_ptr + curr_tlv_len +
							(num_padding_bytes *
							 num_of_elems);
						buf_mov_len =
							param_buf_len - (buf_idx +
									 curr_tlv_len);

						wmi_tlv_OS_MEMMOVE(dst_addr,
								   src_addr,
								   buf_mov_len);
					}

					/* Move subsequent elements of array down by number of
					 * bytes to be padded for one element and alse set
					 * padding bytes to zero */
					tlv_buf_ptr = buf_ptr;
					for (i = 0; i < num_of_elems; i++) {
						src_addr =
							tlv_buf_ptr + in_tlv_len;
						if (i != (num_of_elems - 1)) {
							/* Need not move anything for last element
							 * in the array */
							dst_addr =
								tlv_buf_ptr +
								in_tlv_len +
								num_padding_bytes;
							buf_mov_len =
								curr_tlv_len -
								((i +
								  1) * in_tlv_len);

							wmi_tlv_OS_MEMMOVE
								(dst_addr, src_addr,
								buf_mov_len);
						}

						/* Set the padding bytes to zeroes */
						wmi_tlv_OS_MEMZERO(src_addr,
								   num_padding_bytes);

						tlv_buf_ptr +=
							attr_struct_ptr.
							tag_struct_size;
					}

					/* Update the number of padding bytes to total number
					 * of bytes padded for all elements in the array */
					num_padding_bytes =
						num_padding_bytes * num_of_elems;

					new_tlv_buf = buf_ptr;
				} else {
					/* Incoming structure size is greater than expected size
					 * then this needs shrinking for each element in the array */

					/* Find amount of bytes to be shrinked for one element */
					num_padding_bytes = tlv_size_diff * -1;

					/* Move subsequent elements of array up by number of bytes
					 * to be shrinked for one element */
					tlv_buf_ptr = buf_ptr;
					for (i = 0; i < (num_of_elems - 1); i++) {
						src_addr =
							tlv_buf_ptr + in_tlv_len;
						dst_addr =
							tlv_buf_ptr + in_tlv_len +
							num_padding_bytes;
						buf_mov_len =
							curr_tlv_len -
							((i + 1) * in_tlv_len);

						wmi_tlv_OS_MEMMOVE(dst_addr,
								   src_addr,
								   buf_mov_len);

						tlv_buf_ptr +=
							attr_struct_ptr.
							tag_struct_size;
					}

					/* Move subsequent TLVs by number of bytes to be shrinked
					 * for all elements */
					if (param_buf_len >
					    (buf_idx + curr_tlv_len)) {
						src_addr =
							buf_ptr + curr_tlv_len;
						dst_addr =
							buf_ptr + curr_tlv_len +
							(num_padding_bytes *
							 num_of_elems);
						buf_mov_len =
							param_buf_len - (buf_idx +
									 curr_tlv_len);

						wmi_tlv_OS_MEMMOVE(dst_addr,
								   src_addr,
								   buf_mov_len);
					}

					/* Update the number of padding bytes to total number of
					 * bytes shrinked for all elements in the array */
					num_padding_bytes =
						num_padding_bytes * num_of_elems;

					new_tlv_buf = buf_ptr;
				}
			}
#endif
			cmd_param_tlvs_ptr[tlv_index].tlv_ptr = new_tlv_buf;
			cmd_param_tlvs_ptr[tlv_index].num_elements =
				num_of_elems;
			cmd_param_tlvs_ptr[tlv_index].buf_is_allocated = 1;     /* Indicates that buffer is allocated */

		} else if (tlv_size_diff >= 0) {
			/* Warning: some parameter truncation */
			if (tlv_size_diff > 0) {
				wmi_tlv_print_verbose
					("%s: WARN: TLV truncated. tlv_size_diff=%d, curr_tlv_len=%d\n",
					__func__, tlv_size_diff, curr_tlv_len);
			}
			/* TODO: this next line needs more comments and explanation */
			cmd_param_tlvs_ptr[tlv_index].tlv_ptr =
				(attr_struct_ptr.tag_varied_size
				 && !curr_tlv_len) ? NULL : (void *)buf_ptr;
			cmd_param_tlvs_ptr[tlv_index].num_elements =
				num_of_elems;
			cmd_param_tlvs_ptr[tlv_index].buf_is_allocated = 0;     /* Indicates that buffer is not allocated */
		} else {
			void *new_tlv_buf = NULL;

			/* Warning: Needs to allocate a larger structure and pad with zeros */
			wmi_tlv_print_verbose
				("%s: WARN: TLV needs padding. tlv_size_diff=%d\n",
				__func__, tlv_size_diff);
#ifndef NO_DYNAMIC_MEM_ALLOC
			/* Dynamic memory allocation is supported */
			wmi_tlv_os_mem_alloc(os_handle, new_tlv_buf,
					     (curr_tlv_len - tlv_size_diff));
			if (new_tlv_buf == NULL) {
				/* Error: unable to alloc memory */
				wmi_tlv_print_error
					("%s: Error: unable to alloc memory (size=%d) for padding the TLV %d\n",
					__func__, (curr_tlv_len - tlv_size_diff),
					curr_tlv_tag);
				goto Error_wmitlv_check_and_pad_tlvs;
			}

			wmi_tlv_OS_MEMZERO(new_tlv_buf,
					   (curr_tlv_len - tlv_size_diff));
			wmi_tlv_OS_MEMCPY(new_tlv_buf, (void *)buf_ptr,
					  curr_tlv_len);
#else
			/* Dynamic memory allocation is not supported. Padding has
			 * to be done with in the existing buffer assuming we have
			 * enough space to grow */
			{
				/* Note: tlv_size_diff is a value less than zero */
				/* Move the Subsequent TLVs by amount of bytes needs to be padded */
				A_UINT8 *src_addr;
				A_UINT8 *dst_addr;
				A_UINT32 src_len;

				num_padding_bytes = (tlv_size_diff * -1);

				src_addr = buf_ptr + curr_tlv_len;
				dst_addr =
					buf_ptr + curr_tlv_len + num_padding_bytes;
				src_len =
					param_buf_len - (buf_idx + curr_tlv_len);

				wmi_tlv_OS_MEMMOVE(dst_addr, src_addr, src_len);

				/* Set the padding bytes to zeroes */
				wmi_tlv_OS_MEMZERO(src_addr, num_padding_bytes);

				new_tlv_buf = buf_ptr;
			}
#endif
			cmd_param_tlvs_ptr[tlv_index].tlv_ptr = new_tlv_buf;
			cmd_param_tlvs_ptr[tlv_index].num_elements =
				num_of_elems;
			cmd_param_tlvs_ptr[tlv_index].buf_is_allocated = 1;     /* Indicates that buffer is allocated */
		}

		tlv_index++;
		remaining_expected_tlvs--;
		buf_ptr += curr_tlv_len + num_padding_bytes;
		buf_idx += curr_tlv_len + num_padding_bytes;
	}

	return 0;
Error_wmitlv_check_and_pad_tlvs:
	if (is_cmd_id) {
		wmitlv_free_allocated_command_tlvs(wmi_cmd_event_id,
						   wmi_cmd_struct_ptr);
	} else {
		wmitlv_free_allocated_event_tlvs(wmi_cmd_event_id,
						 wmi_cmd_struct_ptr);
	}
	*wmi_cmd_struct_ptr = NULL;
	return error;
}

/**
 * wmitlv_check_and_pad_event_tlvs() - tlv helper function
 * @os_handle: os context handle
 * @param_struc_ptr: pointer to tlv structure
 * @param_buf_len: length of tlv parameter
 * @wmi_cmd_event_id: command event id
 * @wmi_cmd_struct_ptr: wmi command structure
 *
 *
 * validate and pad(if necessary) for incoming WMI Event TLVs
 *
 * Return: 0 if success. Return < 0 if failure.
 */
int
wmitlv_check_and_pad_event_tlvs(void *os_handle, void *param_struc_ptr,
				A_UINT32 param_buf_len,
				A_UINT32 wmi_cmd_event_id,
				void **wmi_cmd_struct_ptr)
{
	A_UINT32 is_cmd_id = 0;
	return wmitlv_check_and_pad_tlvs
			(os_handle, param_struc_ptr, param_buf_len, is_cmd_id,
			wmi_cmd_event_id, wmi_cmd_struct_ptr);
}

/**
 * wmitlv_check_and_pad_command_tlvs() - tlv helper function
 * @os_handle: os context handle
 * @param_struc_ptr: pointer to tlv structure
 * @param_buf_len: length of tlv parameter
 * @wmi_cmd_event_id: command event id
 * @wmi_cmd_struct_ptr: wmi command structure
 *
 *
 * validate and pad(if necessary) for incoming WMI Command TLVs
 *
 * Return: 0 if success. Return < 0 if failure.
 */
int
wmitlv_check_and_pad_command_tlvs(void *os_handle, void *param_struc_ptr,
				  A_UINT32 param_buf_len,
				  A_UINT32 wmi_cmd_event_id,
				  void **wmi_cmd_struct_ptr)
{
	A_UINT32 is_cmd_id = 1;
	return wmitlv_check_and_pad_tlvs
			(os_handle, param_struc_ptr, param_buf_len, is_cmd_id,
			wmi_cmd_event_id, wmi_cmd_struct_ptr);
}

/**
 * wmitlv_free_allocated_tlvs() - tlv helper function
 * @is_cmd_id: bollean to check if cmd or event tlv
 * @cmd_event_id: command or event id
 * @wmi_cmd_struct_ptr: wmi command structure
 *
 *
 * free any allocated buffers for WMI Event/Command TLV processing
 *
 * Return: none
 */
static void wmitlv_free_allocated_tlvs(A_UINT32 is_cmd_id,
				       A_UINT32 cmd_event_id,
				       void **wmi_cmd_struct_ptr)
{
	void *ptr = *wmi_cmd_struct_ptr;

	if (!ptr) {
		wmi_tlv_print_error("%s: Nothing to free for CMD/Event 0x%x\n",
				    __func__, cmd_event_id);
		return;
	}
#ifndef NO_DYNAMIC_MEM_ALLOC

/* macro to free that previously allocated memory for this TLV. When (op==FREE_TLV_ELEM). */
#define WMITLV_OP_FREE_TLV_ELEM_macro(param_ptr, param_len, wmi_cmd_event_id, elem_tlv_tag, elem_struc_type, elem_name, var_len, arr_size)  \
	if ((((WMITLV_TYPEDEF_STRUCT_PARAMS_TLVS(wmi_cmd_event_id) *)ptr)->WMITLV_FIELD_BUF_IS_ALLOCATED(elem_name)) &&	\
	    (((WMITLV_TYPEDEF_STRUCT_PARAMS_TLVS(wmi_cmd_event_id) *)ptr)->elem_name != NULL)) \
	{ \
		wmi_tlv_os_mem_free(((WMITLV_TYPEDEF_STRUCT_PARAMS_TLVS(wmi_cmd_event_id) *)ptr)->elem_name); \
	}

#define WMITLV_FREE_TLV_ELEMS(id)	     \
case id: \
{ \
	WMITLV_TABLE(id, FREE_TLV_ELEM, NULL, 0)     \
} \
break;

	if (is_cmd_id) {
		switch (cmd_event_id) {
			WMITLV_ALL_CMD_LIST(WMITLV_FREE_TLV_ELEMS);
		default:
			wmi_tlv_print_error
				("%s: ERROR: Cannot find the TLVs attributes for Cmd=0x%x, %d\n",
				__func__, cmd_event_id, cmd_event_id);
		}
	} else {
		switch (cmd_event_id) {
			WMITLV_ALL_EVT_LIST(WMITLV_FREE_TLV_ELEMS);
		default:
			wmi_tlv_print_error
				("%s: ERROR: Cannot find the TLVs attributes for Cmd=0x%x, %d\n",
				__func__, cmd_event_id, cmd_event_id);
		}
	}

	wmi_tlv_os_mem_free(*wmi_cmd_struct_ptr);
	*wmi_cmd_struct_ptr = NULL;
#endif

	return;
}

/**
 * wmitlv_free_allocated_command_tlvs() - tlv helper function
 * @cmd_event_id: command or event id
 * @wmi_cmd_struct_ptr: wmi command structure
 *
 *
 * free any allocated buffers for WMI Event/Command TLV processing
 *
 * Return: none
 */
void wmitlv_free_allocated_command_tlvs(A_UINT32 cmd_event_id,
					void **wmi_cmd_struct_ptr)
{
	wmitlv_free_allocated_tlvs(1, cmd_event_id, wmi_cmd_struct_ptr);
}

/**
 * wmitlv_free_allocated_event_tlvs() - tlv helper function
 * @cmd_event_id: command or event id
 * @wmi_cmd_struct_ptr: wmi command structure
 *
 *
 * free any allocated buffers for WMI Event/Command TLV processing
 *
 * Return: none
 */
void wmitlv_free_allocated_event_tlvs(A_UINT32 cmd_event_id,
				      void **wmi_cmd_struct_ptr)
{
	wmitlv_free_allocated_tlvs(0, cmd_event_id, wmi_cmd_struct_ptr);
}

/**
 * wmi_versions_are_compatible() - tlv helper function
 * @vers1: host wmi version
 * @vers2: target wmi version
 *
 *
 * check if two given wmi versions are compatible
 *
 * Return: none
 */
int
wmi_versions_are_compatible(wmi_abi_version *vers1, wmi_abi_version *vers2)
{
	if ((vers1->abi_version_ns_0 != vers2->abi_version_ns_0) ||
	    (vers1->abi_version_ns_1 != vers2->abi_version_ns_1) ||
	    (vers1->abi_version_ns_2 != vers2->abi_version_ns_2) ||
	    (vers1->abi_version_ns_3 != vers2->abi_version_ns_3)) {
		/* The namespaces are different. Incompatible. */
		return 0;
	}

	if (vers1->abi_version_0 != vers2->abi_version_0) {
		/* The major or minor versions are different. Incompatible */
		return 0;
	}
	/* We ignore the build version */
	return 1;
}

/**
 * wmi_versions_can_downgrade() - tlv helper function
 * @version_whitelist_table: version table
 * @my_vers: host version
 * @opp_vers: target version
 * @out_vers: downgraded version
 *
 *
 * check if target wmi version can be downgraded
 *
 * Return: 0 if success. Return < 0 if failure.
 */
static int
wmi_versions_can_downgrade(int num_whitelist,
			   wmi_whitelist_version_info *version_whitelist_table,
			   wmi_abi_version *my_vers,
			   wmi_abi_version *opp_vers,
			   wmi_abi_version *out_vers)
{
	A_UINT8 can_try_to_downgrade;
	A_UINT32 my_major_vers = WMI_VER_GET_MAJOR(my_vers->abi_version_0);
	A_UINT32 my_minor_vers = WMI_VER_GET_MINOR(my_vers->abi_version_0);
	A_UINT32 opp_major_vers = WMI_VER_GET_MAJOR(opp_vers->abi_version_0);
	A_UINT32 opp_minor_vers = WMI_VER_GET_MINOR(opp_vers->abi_version_0);
	A_UINT32 downgraded_minor_vers;

	if ((my_vers->abi_version_ns_0 != opp_vers->abi_version_ns_0) ||
	    (my_vers->abi_version_ns_1 != opp_vers->abi_version_ns_1) ||
	    (my_vers->abi_version_ns_2 != opp_vers->abi_version_ns_2) ||
	    (my_vers->abi_version_ns_3 != opp_vers->abi_version_ns_3)) {
		/* The namespaces are different. Incompatible. */
		can_try_to_downgrade = false;
	} else if (my_major_vers != opp_major_vers) {
		/* Major version is different. Incompatible and cannot downgrade. */
		can_try_to_downgrade = false;
	} else {
		/* Same major version. */

		if (my_minor_vers < opp_minor_vers) {
			/* Opposite party is newer. Incompatible and cannot downgrade. */
			can_try_to_downgrade = false;
		} else if (my_minor_vers > opp_minor_vers) {
			/* Opposite party is older. Check whitelist if we can downgrade */
			can_try_to_downgrade = true;
		} else {
			/* Same version */
			wmi_tlv_OS_MEMCPY(out_vers, my_vers,
					  sizeof(wmi_abi_version));
			return 1;
		}
	}

	if (!can_try_to_downgrade) {
		wmi_tlv_print_error("%s: Warning: incompatible WMI version.\n",
				    __func__);
		wmi_tlv_OS_MEMCPY(out_vers, my_vers, sizeof(wmi_abi_version));
		return 0;
	}
	/* Try to see we can downgrade the supported version */
	downgraded_minor_vers = my_minor_vers;
	while (downgraded_minor_vers > opp_minor_vers) {
		A_UINT8 downgraded = false;
		int i;

		for (i = 0; i < num_whitelist; i++) {
			if (version_whitelist_table[i].major != my_major_vers) {
				continue;       /* skip */
			}
			if ((version_whitelist_table[i].namespace_0 !=
			     my_vers->abi_version_ns_0)
			    || (version_whitelist_table[i].namespace_1 !=
				my_vers->abi_version_ns_1)
			    || (version_whitelist_table[i].namespace_2 !=
				my_vers->abi_version_ns_2)
			    || (version_whitelist_table[i].namespace_3 !=
				my_vers->abi_version_ns_3)) {
				continue;       /* skip */
			}
			if (version_whitelist_table[i].minor ==
			    downgraded_minor_vers) {
				/* Found the next version that I can downgrade */
				wmi_tlv_print_error
					("%s: Note: found a whitelist entry to downgrade. wh. list ver: %d,%d,0x%x 0x%x 0x%x 0x%x\n",
					__func__, version_whitelist_table[i].major,
					version_whitelist_table[i].minor,
					version_whitelist_table[i].namespace_0,
					version_whitelist_table[i].namespace_1,
					version_whitelist_table[i].namespace_2,
					version_whitelist_table[i].namespace_3);
				downgraded_minor_vers--;
				downgraded = true;
				break;
			}
		}
		if (!downgraded) {
			break;  /* Done since we did not find any whitelist to downgrade version */
		}
	}
	wmi_tlv_OS_MEMCPY(out_vers, my_vers, sizeof(wmi_abi_version));
	out_vers->abi_version_0 =
		WMI_VER_GET_VERSION_0(my_major_vers, downgraded_minor_vers);
	if (downgraded_minor_vers != opp_minor_vers) {
		wmi_tlv_print_error
			("%s: Warning: incompatible WMI version and cannot downgrade.\n",
			__func__);
		return 0;       /* Incompatible */
	} else {
		return 1;       /* Compatible */
	}
}

/**
 * wmi_cmp_and_set_abi_version() - tlv helper function
 * @version_whitelist_table: version table
 * @my_vers: host version
 * @opp_vers: target version
 * @out_vers: downgraded version
 *
 * This routine will compare and set the WMI ABI version.
 * First, compare my version with the opposite side's version.
 * If incompatible, then check the whitelist to see if our side can downgrade.
 * Finally, fill in the final ABI version into the output, out_vers.
 * Return 0 if the output version is compatible
 * Else return 1 if the output version is incompatible
 *
 * Return: 0 if the output version is compatible else < 0.
 */
int
wmi_cmp_and_set_abi_version(int num_whitelist,
			    wmi_whitelist_version_info *
			    version_whitelist_table,
			    struct _wmi_abi_version *my_vers,
			    struct _wmi_abi_version *opp_vers,
			    struct _wmi_abi_version *out_vers)
{
	wmi_tlv_print_verbose
		("%s: Our WMI Version: Mj=%d, Mn=%d, bd=%d, ns0=0x%x ns1:0x%x ns2:0x%x ns3:0x%x\n",
		__func__, WMI_VER_GET_MAJOR(my_vers->abi_version_0),
		WMI_VER_GET_MINOR(my_vers->abi_version_0), my_vers->abi_version_1,
		my_vers->abi_version_ns_0, my_vers->abi_version_ns_1,
		my_vers->abi_version_ns_2, my_vers->abi_version_ns_3);

	wmi_tlv_print_verbose
		("%s: Opposite side WMI Version: Mj=%d, Mn=%d, bd=%d, ns0=0x%x ns1:0x%x ns2:0x%x ns3:0x%x\n",
		__func__, WMI_VER_GET_MAJOR(opp_vers->abi_version_0),
		WMI_VER_GET_MINOR(opp_vers->abi_version_0),
		opp_vers->abi_version_1, opp_vers->abi_version_ns_0,
		opp_vers->abi_version_ns_1, opp_vers->abi_version_ns_2,
		opp_vers->abi_version_ns_3);

	/* By default, the output version is our version. */
	wmi_tlv_OS_MEMCPY(out_vers, my_vers, sizeof(wmi_abi_version));
	if (!wmi_versions_are_compatible(my_vers, opp_vers)) {
		/* Our host version and the given firmware version are incompatible. */
		if (wmi_versions_can_downgrade
			    (num_whitelist, version_whitelist_table, my_vers, opp_vers,
			    out_vers)) {
			/* We can downgrade our host versions to match firmware. */
			wmi_tlv_print_error
				("%s: Host downgraded WMI Versions to match fw. Ret version: Mj=%d, Mn=%d, bd=%d, ns0=0x%x ns1:0x%x ns2:0x%x ns3:0x%x\n",
				__func__,
				WMI_VER_GET_MAJOR(out_vers->abi_version_0),
				WMI_VER_GET_MINOR(out_vers->abi_version_0),
				out_vers->abi_version_1,
				out_vers->abi_version_ns_0,
				out_vers->abi_version_ns_1,
				out_vers->abi_version_ns_2,
				out_vers->abi_version_ns_3);
			return 0;       /* Compatible */
		} else {
			/* Warn: We cannot downgrade our host versions to match firmware. */
			wmi_tlv_print_error
				("%s: WARN: Host WMI Versions mismatch with fw. Ret version: Mj=%d, Mn=%d, bd=%d, ns0=0x%x ns1:0x%x ns2:0x%x ns3:0x%x\n",
				__func__,
				WMI_VER_GET_MAJOR(out_vers->abi_version_0),
				WMI_VER_GET_MINOR(out_vers->abi_version_0),
				out_vers->abi_version_1,
				out_vers->abi_version_ns_0,
				out_vers->abi_version_ns_1,
				out_vers->abi_version_ns_2,
				out_vers->abi_version_ns_3);

			return 1;       /* Incompatible */
		}
	} else {
		/* We are compatible. Our host version is the output version */
		wmi_tlv_print_verbose
			("%s: Host and FW Compatible WMI Versions. Ret version: Mj=%d, Mn=%d, bd=%d, ns0=0x%x ns1:0x%x ns2:0x%x ns3:0x%x\n",
			__func__, WMI_VER_GET_MAJOR(out_vers->abi_version_0),
			WMI_VER_GET_MINOR(out_vers->abi_version_0),
			out_vers->abi_version_1, out_vers->abi_version_ns_0,
			out_vers->abi_version_ns_1, out_vers->abi_version_ns_2,
			out_vers->abi_version_ns_3);
		return 0;       /* Compatible */
	}
}