// SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
/*
 * Firmware code update for FSP systems
 *
 * Copyright 2013-2018 IBM Corp.
 */

#include <skiboot.h>
#include <fsp.h>
#include <fsp-sysparam.h>
#include <lock.h>
#include <device.h>
#include <ccan/endian/endian.h>
#include <errorlog.h>
#include <opal-api.h>
#include <timebase.h>

#include "fsp-codeupdate.h"

enum flash_state {
	FLASH_STATE_ABSENT,
	FLASH_STATE_INVALID, /* IPL side marker lid is invalid */
	FLASH_STATE_READING,
	FLASH_STATE_READ,
	FLASH_STATE_ABORT,
};

enum lid_fetch_side {
	FETCH_T_SIDE_ONLY,
	FETCH_P_SIDE_ONLY,
	FETCH_BOTH_SIDE,
};

static enum flash_state flash_state = FLASH_STATE_INVALID;
static enum lid_fetch_side lid_fetch_side = FETCH_BOTH_SIDE;

/* Image buffers */
static struct opal_sg_list *image_data;
static uint32_t tce_start;
static void *lid_data;
static char validate_buf[VALIDATE_BUF_SIZE];

/* TCE buffer lock */
static struct lock flash_lock = LOCK_UNLOCKED;

/* FW VPD data */
static struct fw_image_vpd fw_vpd[2];

/* Code update related sys parameters */
static uint32_t ipl_side;
static uint32_t hmc_managed;
static uint32_t update_policy;
static uint32_t in_flight_params;

/* If non-NULL, this gets called just before rebooting */
int (*fsp_flash_term_hook)(void);

DEFINE_LOG_ENTRY(OPAL_RC_CU_INIT, OPAL_PLATFORM_ERR_EVT, OPAL_CODEUPDATE,
		OPAL_PLATFORM_FIRMWARE,
		OPAL_PREDICTIVE_ERR_FAULT_RECTIFY_REBOOT, OPAL_NA);

DEFINE_LOG_ENTRY(OPAL_RC_CU_FLASH, OPAL_PLATFORM_ERR_EVT, OPAL_CODEUPDATE,
		OPAL_PLATFORM_FIRMWARE,
		OPAL_PREDICTIVE_ERR_FAULT_RECTIFY_REBOOT, OPAL_NA);

DEFINE_LOG_ENTRY(OPAL_RC_CU_SG_LIST, OPAL_PLATFORM_ERR_EVT, OPAL_CODEUPDATE,
		OPAL_PLATFORM_FIRMWARE,
		OPAL_PREDICTIVE_ERR_FAULT_RECTIFY_REBOOT, OPAL_NA);

DEFINE_LOG_ENTRY(OPAL_RC_CU_COMMIT, OPAL_PLATFORM_ERR_EVT, OPAL_CODEUPDATE,
		OPAL_PLATFORM_FIRMWARE,
		OPAL_PREDICTIVE_ERR_FAULT_RECTIFY_REBOOT, OPAL_NA);

DEFINE_LOG_ENTRY(OPAL_RC_CU_MSG, OPAL_PLATFORM_ERR_EVT, OPAL_CODEUPDATE,
		OPAL_PLATFORM_FIRMWARE,
		OPAL_PREDICTIVE_ERR_FAULT_RECTIFY_REBOOT, OPAL_NA);

DEFINE_LOG_ENTRY(OPAL_RC_CU_NOTIFY, OPAL_PLATFORM_ERR_EVT, OPAL_CODEUPDATE,
		OPAL_PLATFORM_FIRMWARE,
		OPAL_PREDICTIVE_ERR_FAULT_RECTIFY_REBOOT, OPAL_NA);

DEFINE_LOG_ENTRY(OPAL_RC_CU_MARKER_LID, OPAL_PLATFORM_ERR_EVT, OPAL_CODEUPDATE,
		OPAL_PLATFORM_FIRMWARE,
		OPAL_PREDICTIVE_ERR_FAULT_RECTIFY_REBOOT, OPAL_NA);

static inline void code_update_tce_map(uint32_t tce_offset,
				       void *buffer, uint32_t size)
{
	uint32_t tlen = ALIGN_UP(size, TCE_PSIZE);

	fsp_tce_map(PSI_DMA_CODE_UPD + tce_offset, buffer, tlen);
}

static inline void code_update_tce_unmap(uint32_t size)
{
	fsp_tce_unmap(PSI_DMA_CODE_UPD, size);
}

static inline void set_def_fw_version(uint32_t side)
{
	strncpy(fw_vpd[side].mi_keyword, FW_VERSION_UNKNOWN, MI_KEYWORD_SIZE);
	strncpy(fw_vpd[side].ext_fw_id, FW_VERSION_UNKNOWN, ML_KEYWORD_SIZE);
}

/*
 * Get IPL side
 */
static void get_ipl_side(void)
{
	struct dt_node *iplp;
	const char *side = NULL;

	iplp = dt_find_by_path(dt_root, "ipl-params/ipl-params");
	if (iplp)
		side = dt_prop_get_def(iplp, "cec-ipl-side", NULL);

	if (!side || !strcmp(side, "temp"))
		ipl_side = FW_IPL_SIDE_TEMP;
	else
		ipl_side = FW_IPL_SIDE_PERM;

	prlog(PR_NOTICE, "CUPD: IPL SIDE = %s\n",
	      ipl_side == FW_IPL_SIDE_TEMP ? "temp" : "perm");
}


/*
 * Helper routines to retrieve code update related
 * system parameters from FSP.
 */

static void inc_in_flight_param(void)
{
	lock(&flash_lock);
	in_flight_params++;
	unlock(&flash_lock);
}

static void dec_in_flight_param(void)
{
	lock(&flash_lock);
	assert(in_flight_params > 0);
	in_flight_params--;
	unlock(&flash_lock);
}

static void got_code_update_policy(uint32_t param_id __unused, int err_len,
				   void *data __unused)
{
	if (err_len != 4) {
		log_simple_error(&e_info(OPAL_RC_CU_INIT), "CUPD: Error "
			"retrieving code update policy: %d\n", err_len);
	} else {
		update_policy = be32_to_cpu((__be32)update_policy);
		prlog(PR_NOTICE, "CUPD: Code update policy from FSP: %d\n",
		      update_policy);
	}

	dec_in_flight_param();
}

static void get_code_update_policy(void)
{
	int rc;

	inc_in_flight_param();
	rc = fsp_get_sys_param(SYS_PARAM_FLASH_POLICY, &update_policy, 4,
			       got_code_update_policy, NULL);
	if (rc) {
		log_simple_error(&e_info(OPAL_RC_CU_INIT),
			"CUPD: Error %d queueing param request\n", rc);
		dec_in_flight_param();
	}
}

static void got_platform_hmc_managed(uint32_t param_id __unused, int err_len,
				     void *data __unused)
{
	if (err_len != 4) {
		log_simple_error(&e_info(OPAL_RC_CU_INIT), "CUPD: Error "
			"retrieving hmc managed status: %d\n", err_len);
	} else {
		hmc_managed = be32_to_cpu((__be32)hmc_managed);
		prlog(PR_NOTICE, "CUPD: HMC managed status from FSP: %d\n",
		      hmc_managed);
	}

	dec_in_flight_param();
}

static void get_platform_hmc_managed(void)
{
	int rc;

	inc_in_flight_param();
	rc = fsp_get_sys_param(SYS_PARAM_HMC_MANAGED, &hmc_managed, 4,
			       got_platform_hmc_managed, NULL);
	if (rc) {
		log_simple_error(&e_info(OPAL_RC_CU_INIT),
			"CUPD: Error %d queueing param request\n", rc);
		dec_in_flight_param();
	}
}

static bool fw_ipl_side_update_notify(struct fsp_msg *msg)
{
	u32 param_id = fsp_msg_get_data_word(msg, 0);
	int dlen = fsp_msg_get_data_word(msg, 1) & 0xffff;
	uint32_t state = fsp_msg_get_data_word(msg, 2);

	if (param_id != SYS_PARAM_FW_IPL_SIDE)
		return false;

	if (dlen != 4) {
		prlog(PR_DEBUG,
		      "CUPD: Invalid sysparams notify len : 0x%x\n", dlen);
		return false;
	}

	prlog(PR_NOTICE, "CUPD: FW IPL side changed. Disable fast reboot\n");
	prlog(PR_NOTICE, "CUPD: Next IPL side : %s\n",
	      state == FW_IPL_SIDE_TEMP ? "temp" : "perm");

	disable_fast_reboot("FSP IPL Side Change");
	return true;
}

static int64_t code_update_check_state(void)
{
	switch(flash_state) {
	case FLASH_STATE_ABSENT:
		return OPAL_HARDWARE;
	case FLASH_STATE_INVALID:
	case FLASH_STATE_ABORT:
		return OPAL_INTERNAL_ERROR;
	case FLASH_STATE_READING:
		return OPAL_BUSY;
	default:
		break;
	}
	return OPAL_SUCCESS;
}

/*
 * Get common marker LID additional data section
 */
static void *get_adf_sec_data(struct com_marker_adf_sec *adf_sec,
			      uint32_t name)
{
	struct com_marker_adf_header *adf_header;
	int i;

	adf_header = (void *)adf_sec->adf_data;
	for (i = 0; i < be32_to_cpu(adf_sec->adf_cnt); i++) {
		if (be32_to_cpu(adf_header->name) == name)
			return adf_header;

		adf_header = (void *)adf_header + be32_to_cpu(adf_header->size);
	}
	return NULL;
}

/*
 * Parse common marker LID to get FW version details
 *
 * Note:
 *   At present, we are parsing "Service Pack Nomenclature ADF"
 *   section only. If we are adding FW IP support, then we have
 *   to parse "Firmware IP Protection ADF" as well.
 */
static void parse_marker_lid(uint32_t side)
{
	struct com_marker_header *header;
	struct com_marker_mi_section *mi_sec;
	struct com_marker_adf_sec *adf_sec;
	struct com_marker_adf_sp *adf_sp;

	header = (void *)lid_data;

	/* Get MI details */
	mi_sec = (void *)header + be32_to_cpu(header->MI_offset);
	/*
	 * If Marker LID is invalid, then FSP will return a Marker
	 * LID with ASCII zeros for the entire MI keyword.
	 */
	if (mi_sec->mi_keyword[0] == '0')
		return;

	strncpy(fw_vpd[side].mi_keyword, mi_sec->mi_keyword, MI_KEYWORD_SIZE);
	fw_vpd[side].mi_keyword[MI_KEYWORD_SIZE - 1] = '\0';
	prlog(PR_NOTICE, "CUPD: %s side MI Keyword = %s\n",
	      side == 0x00 ? "P" : "T", fw_vpd[side].mi_keyword);

	/* Get ML details */
	adf_sec = (void *)header + be32_to_cpu(mi_sec->adf_offset);
	adf_sp = get_adf_sec_data(adf_sec, ADF_NAME_SP);
	if (!adf_sp)
		return;

	strncpy(fw_vpd[side].ext_fw_id,
		(void *)adf_sp + be32_to_cpu(adf_sp->sp_name_offset),
		ML_KEYWORD_SIZE);
	fw_vpd[side].ext_fw_id[ML_KEYWORD_SIZE - 1] = '\0';
	prlog(PR_NOTICE, "CUPD: %s side ML Keyword = %s\n",
	      side == 0x00 ? "P" : "T", fw_vpd[side].ext_fw_id);
}

static void validate_com_marker_lid(void)
{
	if (!strncmp(fw_vpd[ipl_side].mi_keyword, FW_VERSION_UNKNOWN,
		     sizeof(FW_VERSION_UNKNOWN))) {
		log_simple_error(&e_info(OPAL_RC_CU_MARKER_LID),
			"CUPD: IPL side Marker LID is not valid\n");
		flash_state = FLASH_STATE_INVALID;
		return;
	}

	flash_state = FLASH_STATE_READ;
}

static void fetch_lid_data_complete(struct fsp_msg *msg)
{
	void *buffer;
	size_t length, chunk;
	uint32_t lid_id, offset;
	uint16_t id;
	uint8_t flags, status;
	int rc;

	status = (msg->resp->word1 >> 8) & 0xff;
	flags = (fsp_msg_get_data_word(msg, 0) >> 16) & 0xff;
	id = fsp_msg_get_data_word(msg, 0) & 0xffff;
	lid_id = fsp_msg_get_data_word(msg, 1);
	offset = fsp_msg_get_data_word(msg->resp, 1);
	length = fsp_msg_get_data_word(msg->resp, 2);

	prlog(PR_NOTICE, "CUPD: Marker LID id : size : status = "
	      "0x%x : 0x%x : 0x%x\n",
	      fsp_msg_get_data_word(msg, 1), fsp_msg_get_data_word(msg->resp, 2), status);

	fsp_freemsg(msg);

	switch (status) {
	case FSP_STATUS_SUCCESS: /* Read complete, parse VPD */
		parse_marker_lid(lid_id == P_COM_MARKER_LID_ID ? 0 : 1);
		break;
	case FSP_STATUS_MORE_DATA: /* More data left */
		offset += length;
		chunk = MARKER_LID_SIZE - offset;
		if (chunk > 0) {
			buffer = (void *)PSI_DMA_CODE_UPD + offset;
			rc = fsp_fetch_data_queue(flags, id, lid_id,
						  offset, buffer, &chunk,
						  fetch_lid_data_complete);

			/* If queue msg fails, then continue with marker LID
			 * validation hoping that we have at least boot side
			 * information.
			 */
			if (rc == OPAL_SUCCESS)
				return;
		}
		break;
	default:	/* Fetch LID call failed */
		break;
	}

	/* If required, fetch T side marker LID */
	if (lid_id == P_COM_MARKER_LID_ID &&
	    lid_fetch_side == FETCH_BOTH_SIDE) {
		length = MARKER_LID_SIZE;
		rc = fsp_fetch_data_queue(flags, id, T_COM_MARKER_LID_ID,
					  0, (void *)PSI_DMA_CODE_UPD,
					  &length, fetch_lid_data_complete);

		/* If queue msg fails, then continue with marker LID
		 * validation hoping that we have at least boot side
		 * information.
		 */
		if (rc == OPAL_SUCCESS)
			return;
	}

	lock(&flash_lock);

	/* Validate marker LID data */
	validate_com_marker_lid();
	/* TCE unmap */
	code_update_tce_unmap(MARKER_LID_SIZE);

	unlock(&flash_lock);
}

static void fetch_com_marker_lid(void)
{
	size_t length = MARKER_LID_SIZE;
	uint32_t lid_id;
	int rc;

	/* Read in progress? */
	rc = code_update_check_state();
	if (rc == OPAL_HARDWARE || rc == OPAL_BUSY)
		return;

	if (lid_fetch_side == FETCH_T_SIDE_ONLY) {
		lid_id = T_COM_MARKER_LID_ID;
		set_def_fw_version(FW_IPL_SIDE_TEMP);
	} else if (lid_fetch_side == FETCH_P_SIDE_ONLY) {
		lid_id = P_COM_MARKER_LID_ID;
		set_def_fw_version(FW_IPL_SIDE_PERM);
	} else {
		lid_id = P_COM_MARKER_LID_ID;
		set_def_fw_version(FW_IPL_SIDE_PERM);
		set_def_fw_version(FW_IPL_SIDE_TEMP);
	}

	code_update_tce_map(0, lid_data, length);
	rc = fsp_fetch_data_queue(0x00, 0x05, lid_id, 0,
				  (void *)PSI_DMA_CODE_UPD, &length,
				  fetch_lid_data_complete);
	if (!rc)
		flash_state = FLASH_STATE_READING;
	else
		flash_state = FLASH_STATE_INVALID;
}

/*
 * Add MI and ML keyword details into DT
 */
#define FW_VER_SIZE	64
static void add_opal_firmware_version(void)
{
	struct dt_node *dt_fw;
	char buffer[FW_VER_SIZE];
	int offset;

	dt_fw = dt_find_by_path(dt_root, "ibm,opal/firmware");
	if (!dt_fw)
		return;

	/* MI version */
	offset = snprintf(buffer, FW_VER_SIZE, "MI %s %s",
			  fw_vpd[FW_IPL_SIDE_TEMP].mi_keyword,
			  fw_vpd[FW_IPL_SIDE_PERM].mi_keyword);
	if (ipl_side == FW_IPL_SIDE_TEMP)
		snprintf(buffer + offset, FW_VER_SIZE - offset,
			 " %s", fw_vpd[FW_IPL_SIDE_TEMP].mi_keyword);
	else
		snprintf(buffer + offset, FW_VER_SIZE - offset,
			 " %s", fw_vpd[FW_IPL_SIDE_PERM].mi_keyword);

	dt_add_property(dt_fw, "mi-version", buffer, strlen(buffer));

	/* ML version */
	offset = snprintf(buffer, FW_VER_SIZE, "ML %s %s",
			  fw_vpd[FW_IPL_SIDE_TEMP].ext_fw_id,
			  fw_vpd[FW_IPL_SIDE_PERM].ext_fw_id);
	if (ipl_side == FW_IPL_SIDE_TEMP)
		snprintf(buffer + offset, FW_VER_SIZE - offset,
			 " %s", fw_vpd[FW_IPL_SIDE_TEMP].ext_fw_id);
	else
		snprintf(buffer + offset, FW_VER_SIZE - offset,
			 " %s", fw_vpd[FW_IPL_SIDE_PERM].ext_fw_id);

	dt_add_property(dt_fw, "ml-version", buffer, strlen(buffer));
}

/*
 * This is called right before starting the payload (Linux) to
 * ensure the common marker LID read and parsing has happened
 * before we transfer control.
 */
void fsp_code_update_wait_vpd(bool is_boot)
{
	int waited = 0;

	if (!fsp_present())
		return;

	prlog(PR_NOTICE, "CUPD: Waiting read marker LID"
	      " and in flight parsm completion...\n");

	lock(&flash_lock);
	while(true) {
		if (!(flash_state == FLASH_STATE_READING || in_flight_params))
			break;
		unlock(&flash_lock);
		time_wait_ms(5);
		waited+=5;
		lock(&flash_lock);
	}
	unlock(&flash_lock);

	if (waited)
		prlog(PR_DEBUG, "CUPD: fsp_code_update_wait_vpd %d\n", waited);

	if (is_boot)
		add_opal_firmware_version();
}

static int code_update_start(void)
{
	struct fsp_msg *msg;
	int rc;
	uint16_t comp = 0x00;	/* All components */
	uint8_t side = OPAL_COMMIT_TMP_SIDE;	/* Temporary side */

	msg = fsp_mkmsg(FSP_CMD_FLASH_START, 1, side << 16 | comp);
	if (!msg) {
		log_simple_error(&e_info(OPAL_RC_CU_MSG),
			"CUPD: CMD_FLASH_START message allocation failed !\n");
		return OPAL_INTERNAL_ERROR;
	}
	if (fsp_sync_msg(msg, false)) {
		fsp_freemsg(msg);
		return OPAL_INTERNAL_ERROR;
	}
	rc = (msg->resp->word1 >> 8) & 0xff;
	fsp_freemsg(msg);
	return rc;
}

static int code_update_write_lid(uint32_t lid_id, uint32_t size)
{
	struct fsp_msg *msg;
	int rc, n_pairs = 1;

	msg = fsp_mkmsg(FSP_CMD_FLASH_WRITE, 5, lid_id,
			n_pairs, 0, tce_start, size);
	if (!msg) {
		log_simple_error(&e_info(OPAL_RC_CU_MSG),
			"CUPD: CMD_FLASH_WRITE message allocation failed !\n");
		return OPAL_INTERNAL_ERROR;
	}
	if (fsp_sync_msg(msg, false)) {
		fsp_freemsg(msg);
		return OPAL_INTERNAL_ERROR;
	}
	rc = (msg->resp->word1 >> 8) & 0xff;
	fsp_freemsg(msg);
	return rc;
}

static int code_update_del_lid(uint32_t lid_id)
{
	struct fsp_msg *msg;
	int rc;

	msg = fsp_mkmsg(FSP_CMD_FLASH_DEL, 1, lid_id);
	if (!msg) {
		log_simple_error(&e_info(OPAL_RC_CU_MSG),
			"CUPD: CMD_FLASH_DEL message allocation failed !\n");
		return OPAL_INTERNAL_ERROR;
	}
	if (fsp_sync_msg(msg, false)) {
		fsp_freemsg(msg);
		return OPAL_INTERNAL_ERROR;
	}
	rc = (msg->resp->word1 >> 8) & 0xff;
	fsp_freemsg(msg);
	return rc;
}

static int code_update_complete(uint32_t cmd)
{
	struct fsp_msg *msg;
	int rc;

	msg = fsp_mkmsg(cmd, 0);
	if (!msg) {
		log_simple_error(&e_info(OPAL_RC_CU_MSG),
			"CUPD: CUPD COMPLETE message allocation failed !\n");
		return OPAL_INTERNAL_ERROR;
	}
	if (fsp_sync_msg(msg, false)) {
		fsp_freemsg(msg);
		return OPAL_INTERNAL_ERROR;
	}
	rc = (msg->resp->word1 >> 8) & 0xff;
	fsp_freemsg(msg);
	return rc;
}

static int code_update_swap_side(void)
{
	struct fsp_msg *msg;
	int rc;

	msg = fsp_mkmsg(FSP_CMD_FLASH_SWAP, 0);
	if (!msg) {
		log_simple_error(&e_info(OPAL_RC_CU_MSG),
			"CUPD: CMD_FLASH_SWAP message allocation failed !\n");
		return OPAL_INTERNAL_ERROR;
	}

	if (fsp_sync_msg(msg, false)) {
		fsp_freemsg(msg);
		return OPAL_INTERNAL_ERROR;
	}
	rc = (msg->resp->word1 >> 8) & 0xff;
	fsp_freemsg(msg);
	return rc;
}

static int code_update_set_ipl_side(void)
{
	struct fsp_msg *msg;
	uint8_t side = FW_IPL_SIDE_TEMP; /* Next IPL side */
	int rc;

	msg = fsp_mkmsg(FSP_CMD_SET_IPL_SIDE, 1, side << 16);
	if (!msg) {
		log_simple_error(&e_info(OPAL_RC_CU_MSG),
			"CUPD: CMD_SET_IPL_SIDE message allocation failed!\n");
		return OPAL_INTERNAL_ERROR;
	}
	if (fsp_sync_msg(msg, false)) {
		fsp_freemsg(msg);
		log_simple_error(&e_info(OPAL_RC_CU_MSG),
			"CUPD: Setting next IPL side failed!\n");
		return OPAL_INTERNAL_ERROR;
	}
	rc = (msg->resp->word1 >> 8) & 0xff;
	fsp_freemsg(msg);
	return rc;
}

static void code_update_commit_complete(struct fsp_msg *msg)
{
	int rc;
	uint8_t type;

	rc = (msg->resp->word1 >> 8) & 0xff;
	type = (msg->word1 >> 8) & 0xff;
	fsp_freemsg(msg);
	if (rc) {
		log_simple_error(&e_info(OPAL_RC_CU_COMMIT),
			"CUPD: Code update commit failed, err 0x%x\n", rc);
		return;
	}

	/* Reset cached VPD data */
	lock(&flash_lock);

	/* Find commit type */
	if (type == 0x01) {
		lid_fetch_side = FETCH_P_SIDE_ONLY;
	} else if (type == 0x02)
		lid_fetch_side = FETCH_T_SIDE_ONLY;
	else
		lid_fetch_side = FETCH_BOTH_SIDE;

	fetch_com_marker_lid();

	unlock(&flash_lock);
}

static int code_update_commit(uint32_t cmd)
{
	struct fsp_msg *msg;

	msg = fsp_mkmsg(cmd, 0);
	if (!msg) {
		log_simple_error(&e_info(OPAL_RC_CU_MSG),
			"CUPD: COMMIT message allocation failed !\n");
		return OPAL_INTERNAL_ERROR;
	}
	if (fsp_queue_msg(msg, code_update_commit_complete)) {
		log_simple_error(&e_info(OPAL_RC_CU_COMMIT),
			"CUPD: Failed to queue code update commit message\n");
		fsp_freemsg(msg);
		return OPAL_INTERNAL_ERROR;
	}
	return OPAL_SUCCESS;
}

/*
 * Inband code update is allowed?
 */
static int64_t validate_inband_policy(void)
{
	/* Quirk:
	 *  If the code update policy is out-of-band, but the system
	 *  is not HMC-managed, then inband update is allowed.
	 */
	if (hmc_managed != PLATFORM_HMC_MANAGED)
		return 0;
	if (update_policy == INBAND_UPDATE_ALLOWED)
		return 0;

	return -1;
}

/*
 * Validate magic Number
 */
static int64_t validate_magic_num(uint16_t magic)
{
	if (magic != IMAGE_MAGIC_NUMBER)
		return -1;
	return 0;
}

/*
 * Compare MI keyword to make sure candidate image
 * is valid for this platform.
 */
static int64_t validate_image_version(struct update_image_header *header,
				      uint32_t *result)
{
	struct fw_image_vpd vpd;
	int t_valid = 0, p_valid = 0, cton_ver = -1, ptot_ver = -1;

	/* Valid flash image level? */
	if (strncmp(fw_vpd[0].mi_keyword, FW_VERSION_UNKNOWN,
		    sizeof(FW_VERSION_UNKNOWN)) != 0)
		p_valid = 1;

	if (strncmp(fw_vpd[1].mi_keyword, FW_VERSION_UNKNOWN,
		    sizeof(FW_VERSION_UNKNOWN)) != 0)
		t_valid = 1;

	/* Validate with IPL side image */
	vpd = fw_vpd[ipl_side];

	/* Validate platform identifier (first two char of MI keyword) */
	if (strncmp(vpd.mi_keyword, header->mi_keyword_data, 2) != 0) {
		*result = VALIDATE_INVALID_IMG;
		return OPAL_SUCCESS;
	}

	/* Don't flash different FW series (like P7 image on P8) */
	if (vpd.mi_keyword[2] != header->mi_keyword_data[2]) {
		*result = VALIDATE_INVALID_IMG;
		return OPAL_SUCCESS;
	}

	/* Get current to new version difference */
	cton_ver = strncmp(vpd.mi_keyword + 3, header->mi_keyword_data + 3, 6);

	/* Get P to T version difference */
	if (t_valid && p_valid)
		ptot_ver = strncmp(fw_vpd[0].mi_keyword + 3,
				   fw_vpd[1].mi_keyword + 3, 6);

	/* Update validation result */
	if (ipl_side == FW_IPL_SIDE_TEMP) {
		if (!ptot_ver && cton_ver > 0) /* downgrade T side */
			*result = VALIDATE_TMP_UPDATE_DL;
		else if (!ptot_ver && cton_ver <= 0) /* upgrade T side */
			*result = VALIDATE_TMP_UPDATE;
		else if (cton_ver > 0) /* Implied commit & downgrade T side */
			*result = VALIDATE_TMP_COMMIT_DL;
		else /* Implied commit & upgrade T side */
			*result = VALIDATE_TMP_COMMIT;
	} else {
		if (!t_valid)	/* Current unknown */
			*result = VALIDATE_CUR_UNKNOWN;
		else if (cton_ver > 0) /* downgrade FW version */
			*result = VALIDATE_TMP_UPDATE_DL;
		else		/* upgrade FW version */
			*result = VALIDATE_TMP_UPDATE;
	}
	return OPAL_SUCCESS;
}

/*
 * Validate candidate image
 */
static int validate_candidate_image(uint64_t buffer,
				    uint32_t size, uint32_t *result)
{
	struct update_image_header *header;
	int rc = OPAL_PARAMETER;

	if (size < VALIDATE_BUF_SIZE)
		goto out;

	rc = code_update_check_state();
	if (rc != OPAL_SUCCESS)
		goto out;

	if (validate_inband_policy() != 0) {
		*result = VALIDATE_FLASH_AUTH;
		rc = OPAL_SUCCESS;
		goto out;
	}

	memcpy(validate_buf, (void *)buffer, VALIDATE_BUF_SIZE);
	header = (struct update_image_header *)validate_buf;

	if (validate_magic_num(be16_to_cpu(header->magic)) != 0) {
		*result = VALIDATE_INVALID_IMG;
		rc = OPAL_SUCCESS;
		goto out;
	}
	rc = validate_image_version(header, result);
out:
	return rc;
}

static int validate_out_buf_mi_data(void *buffer, int offset, uint32_t result)
{
	struct update_image_header *header = (void *)validate_buf;

	/* Current T & P side MI data */
	offset += snprintf(buffer + offset, VALIDATE_BUF_SIZE - offset,
			   "MI %s %s\n",
			   fw_vpd[1].mi_keyword, fw_vpd[0].mi_keyword);

	/* New T & P side MI data */
	offset += snprintf(buffer + offset, VALIDATE_BUF_SIZE - offset,
			   "MI %s", header->mi_keyword_data);
	if (result == VALIDATE_TMP_COMMIT_DL ||
	    result == VALIDATE_TMP_COMMIT)
		offset += snprintf(buffer + offset,
				   VALIDATE_BUF_SIZE - offset,
				   " %s\n", fw_vpd[1].mi_keyword);
	else
		offset += snprintf(buffer + offset,
				   VALIDATE_BUF_SIZE - offset,
				   " %s\n", fw_vpd[0].mi_keyword);
	return offset;
}

static int validate_out_buf_ml_data(void *buffer, int offset, uint32_t result)
{
	struct update_image_header *header = (void *)validate_buf;
	/* Candidate image ML data */
	char *ext_fw_id = (void *)header->data;

	/* Current T & P side ML data */
	offset += snprintf(buffer + offset, VALIDATE_BUF_SIZE - offset,
			   "ML %s %s\n",
			   fw_vpd[1].ext_fw_id, fw_vpd[0].ext_fw_id);

	/* New T & P side ML data */
	offset += snprintf(buffer + offset, VALIDATE_BUF_SIZE - offset,
			   "ML %s", ext_fw_id);
	if (result == VALIDATE_TMP_COMMIT_DL ||
	    result == VALIDATE_TMP_COMMIT)
		offset += snprintf(buffer + offset,
				   VALIDATE_BUF_SIZE - offset,
				   " %s\n", fw_vpd[1].ext_fw_id);
	else
		offset += snprintf(buffer + offset,
				   VALIDATE_BUF_SIZE - offset,
				   " %s\n", fw_vpd[0].ext_fw_id);

	return offset;
}

/*
 * Copy LID data to TCE buffer
 */
static int get_lid_data(struct opal_sg_list *list,
			int lid_size, int lid_offset)
{
	struct opal_sg_list *sg;
	struct opal_sg_entry *entry;
	int length, num_entries, i, buf_pos = 0;
	int map_act, map_size;
	bool last = false;

	/* Reset TCE start address */
	tce_start = 0;

	for (sg = list; sg; sg = (struct opal_sg_list*)be64_to_cpu(sg->next)) {
		length = (be64_to_cpu(sg->length) & ~(SG_LIST_VERSION << 56)) - 16;
		num_entries = length / sizeof(struct opal_sg_entry);
		if (num_entries <= 0)
			return -1;

		for (i = 0; i < num_entries; i++) {
			entry = &sg->entry[i];

			/*
			 * Continue until we get data block which
			 * contains LID data
			 */
			if (lid_offset > be64_to_cpu(entry->length)) {
				lid_offset -= be64_to_cpu(entry->length);
				continue;
			}

                        /*
			 * SG list entry size can be more than 4k.
			 * Map only required pages, instead of
			 * mapping entire entry.
			 */
			map_act = be64_to_cpu(entry->length);
			map_size = be64_to_cpu(entry->length);

			/* First TCE mapping */
			if (!tce_start) {
				tce_start = PSI_DMA_CODE_UPD +
						(lid_offset & 0xfff);
				map_act = be64_to_cpu(entry->length) - lid_offset;
				lid_offset &= ~0xfff;
				map_size = be64_to_cpu(entry->length) - lid_offset;
			}

			/* Check pending LID size to map */
			if (lid_size <= map_act) {
				/* (map_size - map_act) gives page
				 * start to tce offset difference.
				 * This is required when LID size
				 * is <= 4k.
				 */
				map_size = (map_size - map_act) + lid_size;
				last = true;
			}

			/* Ajust remaining size to map */
			lid_size -= map_act;

			/* TCE mapping */
			code_update_tce_map(buf_pos,
					    (void*)(be64_to_cpu(entry->data)
						    + lid_offset),
					    map_size);
			buf_pos += map_size;
			/* Reset LID offset count */
			lid_offset = 0;

			if (last)
				return OPAL_SUCCESS;
		}
	} /* outer loop */
	return -1;
}

/*
 * If IPL side is T, then swap P & T sides to add
 * new fix to T side.
 */
static int validate_ipl_side(void)
{
	if (ipl_side == FW_IPL_SIDE_PERM)
		return 0;
	return code_update_swap_side();
}

static int64_t fsp_opal_validate_flash(uint64_t buffer,
				       __be32 *size, __be32 *result)
{
	int64_t rc = 0;
	int offset;
	uint32_t r;

	lock(&flash_lock);

	rc = validate_candidate_image(buffer, be32_to_cpu(*size), &r);
	/* Fill output buffer
	 *
	 * Format:
	 *   MI<sp>current-T-image<sp>current-P-image<0x0A>
	 *   MI<sp>new-T-image<sp>new-P-image<0x0A>
	 *   ML<sp>current-T-image<sp>current-P-image<0x0A>
	 *   ML<sp>new-T-image<sp>new-P-image<0x0A>
	 */
	if (!rc && (r != VALIDATE_FLASH_AUTH && r != VALIDATE_INVALID_IMG)) {
		/* Clear output buffer */
		memset((void *)buffer, 0, VALIDATE_BUF_SIZE);

		offset = validate_out_buf_mi_data((void *)buffer, 0, r);
		offset += validate_out_buf_ml_data((void *)buffer, offset, r);
		*size = cpu_to_be32(offset);
	}
	*result = cpu_to_be32(r);

	unlock(&flash_lock);
	return rc;
}

/* Commit/Reject T side image */
static int64_t fsp_opal_manage_flash(uint8_t op)
{
	uint32_t cmd;
	int rc;

	lock(&flash_lock);
	rc = code_update_check_state();
	unlock(&flash_lock);

	if (rc != OPAL_SUCCESS)
		return rc;

	if (op != OPAL_REJECT_TMP_SIDE && op != OPAL_COMMIT_TMP_SIDE)
		return OPAL_PARAMETER;

	if ((op == OPAL_COMMIT_TMP_SIDE && ipl_side == FW_IPL_SIDE_PERM) ||
	    (op == OPAL_REJECT_TMP_SIDE && ipl_side == FW_IPL_SIDE_TEMP))
		return OPAL_ACTIVE_SIDE_ERR;

	if (op == OPAL_COMMIT_TMP_SIDE)
		cmd = FSP_CMD_FLASH_NORMAL;
	else
		cmd = FSP_CMD_FLASH_REMOVE;

	return code_update_commit(cmd);
}

static int fsp_flash_firmware(void)
{
	struct update_image_header *header;
	struct lid_index_entry *idx_entry;
	struct opal_sg_list *list;
	struct opal_sg_entry *entry;
	int rc, i;

	/* Make sure no outstanding LID read is in progress */
	rc = code_update_check_state();
	if (rc == OPAL_BUSY)
		fsp_code_update_wait_vpd(false);

	/* Get LID Index */
	list = image_data;
	if (!list)
		goto out;
	entry = &list->entry[0];
	header = (struct update_image_header *)be64_to_cpu(entry->data);
	idx_entry = (void *)header + be16_to_cpu(header->lid_index_offset);

	/* FIXME:
	 *   At present we depend on FSP to validate CRC for
	 *   individual LIDs. Calculate and validate individual
	 *   LID CRC here.
	 */

	if (validate_ipl_side() != 0) {
		log_simple_error(&e_info(OPAL_RC_CU_FLASH), "CUPD: "
				 "Rename (Swap T and P) failed!\n");
		goto out;
	}

	/* Set next IPL side */
	if (code_update_set_ipl_side() != 0) {
		log_simple_error(&e_info(OPAL_RC_CU_FLASH), "CUPD: "
				 "Setting next IPL side failed!\n");
		goto out;
	}

	/* Start code update process */
	if (code_update_start() != 0) {
		log_simple_error(&e_info(OPAL_RC_CU_FLASH), "CUPD: "
				 "Code update start failed!\n");
		goto out;
	}

	/*
	 * Delete T side LIDs before writing.
	 *
	 * Note:
	 *   - Applicable for FWv >= 760.
	 *   - Current Code Update design is to ignore
	 *     any delete lid failure, and continue with
	 *     the update.
	 */
	rc = code_update_del_lid(DEL_UPD_SIDE_LIDS);

	if (rc)
		prlog(PR_TRACE, "CUPD: Failed to delete LIDs (%d). This is okay, continuing..", rc);

	for (i = 0; i < be16_to_cpu(header->number_lids); i++) {
		if (be32_to_cpu(idx_entry->size) > LID_MAX_SIZE) {
			log_simple_error(&e_info(OPAL_RC_CU_FLASH), "CUPD: LID"
				" (0x%x) size 0x%x is > max LID size (0x%x).\n",
				 be32_to_cpu(idx_entry->id),
				 be32_to_cpu(idx_entry->size), LID_MAX_SIZE);
			goto abort_update;
		}

		rc = get_lid_data(list, be32_to_cpu(idx_entry->size),
				  be32_to_cpu(idx_entry->offset));
		if (rc) {
			log_simple_error(&e_info(OPAL_RC_CU_FLASH), "CUPD: "
				"Failed to parse LID from firmware image."
				" (rc : %d).\n", rc);
			goto abort_update;
		}

		rc = code_update_write_lid(be32_to_cpu(idx_entry->id),
					   be32_to_cpu(idx_entry->size));
		if (rc) {
			log_simple_error(&e_info(OPAL_RC_CU_FLASH), "CUPD: "
				"Failed to write LID to FSP. (rc : %d).\n", rc);
			goto abort_update;
		}

		/* Unmap TCE */
		code_update_tce_unmap(PSI_DMA_CODE_UPD_SIZE);

		/* Next LID index */
		idx_entry = (void *)idx_entry + sizeof(struct lid_index_entry);
	}

	/* Code update completed */
	rc = code_update_complete(FSP_CMD_FLASH_COMPLETE);

	return rc;

abort_update:
	rc = code_update_complete(FSP_CMD_FLASH_ABORT);
	if (rc)
		log_simple_error(&e_info(OPAL_RC_CU_FLASH), "CUPD: "
			 "Code update abort command failed. (rc : %d).", rc);

out:
	return -1;
}

static int64_t validate_sglist(struct opal_sg_list *list)
{
	struct opal_sg_list *sg;
	struct opal_sg_entry *prev_entry, *entry;
	int length, num_entries, i;

	prev_entry = NULL;
	for (sg = list; sg; sg = (struct opal_sg_list*)be64_to_cpu(sg->next)) {
		length = (be64_to_cpu(sg->length) & ~(SG_LIST_VERSION << 56)) - 16;
		num_entries = length / sizeof(struct opal_sg_entry);
		if (num_entries <= 0)
			return -1;

		for (i = 0; i < num_entries; i++) {
			entry = &sg->entry[i];

			/* All entries must be aligned */
			if (((uint64_t)be64_to_cpu(entry->data)) & 0xfff)
				return OPAL_PARAMETER;

			/* All non-terminal entries size must be aligned */
			if (prev_entry && (be64_to_cpu(prev_entry->length) & 0xfff))
				return OPAL_PARAMETER;

			prev_entry = entry;
		}
	}
	return OPAL_SUCCESS;
}

static int64_t fsp_opal_update_flash(struct opal_sg_list *list)
{
	struct opal_sg_entry *entry;
	int length, num_entries, result = 0, rc = OPAL_PARAMETER;

	/* Ensure that the sg list honors our alignment requirements */
	rc = validate_sglist(list);
	if (rc) {
		log_simple_error(&e_info(OPAL_RC_CU_SG_LIST),
			"CUPD: sglist fails alignment requirements\n");
		return rc;
	}

	lock(&flash_lock);
	if (!list) {	/* Cancel update request */
		fsp_flash_term_hook = NULL;
		image_data = NULL;
		rc = OPAL_SUCCESS;
		goto out;
	}

	disable_fast_reboot("FSP Code Update");

	length = (be64_to_cpu(list->length) & ~(SG_LIST_VERSION << 56)) - 16;
	num_entries = length / sizeof(struct opal_sg_entry);
	if (num_entries <= 0)
		goto out;

	/* Validate image header */
	entry = &list->entry[0];
	rc = validate_candidate_image((uint64_t)be64_to_cpu(entry->data),
				      VALIDATE_BUF_SIZE, &result);
	if (!rc && (result != VALIDATE_FLASH_AUTH &&
		   result != VALIDATE_INVALID_IMG)) {
		image_data = list;
		fsp_flash_term_hook = fsp_flash_firmware;
		goto out;
	}

	/* Adjust return code */
	if (result == VALIDATE_FLASH_AUTH)
		rc = OPAL_FLASH_NO_AUTH;
	else if (result == VALIDATE_INVALID_IMG)
		rc = OPAL_INVALID_IMAGE;

out:
	unlock(&flash_lock);
	return rc;
}

/*
 * Code Update notifications
 *
 * Note: At present we just ACK these notifications.
 *       Reset cached VPD data if we are going to support
 *       concurrent image maint in future.
 */
static bool code_update_notify(uint32_t cmd_sub_mod, struct fsp_msg *msg)
{
	int rc;
	uint32_t cmd;

	switch(cmd_sub_mod) {
	case FSP_CMD_FLASH_CACHE:
		cmd = FSP_CMD_FLASH_CACHE_RSP;
		prlog(PR_NOTICE, "CUPD: Update LID cache event [data = 0x%x]\n",
		      fsp_msg_get_data_word(msg, 0));
		break;
	case FSP_CMD_FLASH_OUTC:
	case FSP_CMD_FLASH_OUTR:
	case FSP_CMD_FLASH_OUTS:
		cmd = FSP_CMD_FLASH_OUT_RSP;
		prlog(PR_NOTICE, "CUPD: Out of band commit notify "
		      "[Type = 0x%x]\n", (msg->word1 >> 8) & 0xff);
		break;
	default:
		log_simple_error(&e_info(OPAL_RC_CU_NOTIFY), "CUPD: Unknown "
			"notification [cmd = 0x%x]\n", cmd_sub_mod);
		return false;
	}

	rc = fsp_queue_msg(fsp_mkmsg(cmd, 0), fsp_freemsg);
	if (rc)
		log_simple_error(&e_info(OPAL_RC_CU_NOTIFY), "CUPD: Failed to "
			"queue code update notification response :%d\n", rc);

	return true;
}

/*
 * Handle FSP R/R event.
 *
 * Note:
 *   If FSP R/R happens during code update, then entire system reboots
 *   and comes up with P side image (and T side image will be invalid).
 *   Hence we don't need to handle R/R during code update.
 *
 *   Also if FSP R/R happens in init path (while retrieving in_flight_params)
 *   then system fails to continue booting (because we have not yet loaded
 *   all required data/LID from FSP). Hence we don't need to handle R/R
 *   for system params.
 */
static bool fsp_code_update_rr(uint32_t cmd_sub_mod,
			       struct fsp_msg *msg __unused)
{
	switch (cmd_sub_mod) {
	case FSP_RESET_START:
		lock(&flash_lock);

		if (code_update_check_state() == OPAL_BUSY)
			flash_state = FLASH_STATE_ABORT;

		unlock(&flash_lock);
		return true;
	case FSP_RELOAD_COMPLETE:
		lock(&flash_lock);

		/* Lets try to parse marker LID again, if we failed
		 * to parse marker LID last time.
		 */
		if (code_update_check_state() == OPAL_INTERNAL_ERROR)
			fetch_com_marker_lid();

		unlock(&flash_lock);
		return true;
	}
	return false;
}

static struct fsp_client fsp_cupd_client_rr = {
	        .message = fsp_code_update_rr,
};

static struct fsp_client fsp_get_notify = {
	.message = code_update_notify,
};

void fsp_code_update_init(void)
{
	if (!fsp_present()) {
		flash_state = FLASH_STATE_ABSENT;
		return;
	}

	/* OPAL interface */
	opal_register(OPAL_FLASH_VALIDATE, fsp_opal_validate_flash, 3);
	opal_register(OPAL_FLASH_MANAGE, fsp_opal_manage_flash, 1);
	opal_register(OPAL_FLASH_UPDATE, fsp_opal_update_flash, 1);

	/* register Code Update Class D3 */
	fsp_register_client(&fsp_get_notify, FSP_MCLASS_CODE_UPDATE);
	/* Register for Class AA (FSP R/R) */
	fsp_register_client(&fsp_cupd_client_rr, FSP_MCLASS_RR_EVENT);

	/* Register for firmware IPL side update notification */
	sysparam_add_update_notifier(fw_ipl_side_update_notify);

	/* Flash hook */
	fsp_flash_term_hook = NULL;

	/* Fetch various code update related sys parameters */
	get_ipl_side();
	get_code_update_policy();
	get_platform_hmc_managed();

	/* Fetch common marker LID */
	lid_data = memalign(TCE_PSIZE, MARKER_LID_SIZE);
	if (!lid_data) {
		log_simple_error(&e_info(OPAL_RC_CU_INIT),
			"CUPD: Failed to allocate memory for marker LID\n");
		flash_state = FLASH_STATE_ABSENT;
		return;
	}
	fetch_com_marker_lid();
}