[Skiboot] [RFC 1/2] occ: Add support for OPAL-OCC command/response interface
Cyril Bur
cyrilbur at gmail.com
Tue Jun 6 15:41:18 AEST 2017
On Mon, 2017-06-05 at 10:10 +0530, Shilpasri G Bhat wrote:
> This patch adds support for a shared memory based command/response
> interface between OCC and OPAL. In HOMER, there is an OPAL command
> buffer and an OCC response buffer which is used to send inband
> commands to OCC.
>
> The OPAL-OCC command/response sequence is as follows:
>
> 1. Check if both 'OCC Progress' bit in OCC response flag and 'Cmd Ready'
> bit in OPAL command flag are set to zero. If yes then proceed with
> below steps to send a command to OCC.
> 2. Write the command value, request ID and command specific data
> to the OPAL command buffer.
> 3. Clear the response flag and set the 'Cmd Ready' bit in OPAL command
> flag to indicate command is ready.
> 4. OCC will poll the command flag every 4ms to check if 'Cmd Ready' bit
> is set by OPAL. If the bit is set then OCC will set the 'OCC Progress'
> bit.
> 5. OCC will process the command and write the response to the OCC response
> buffer and set the 'Rsp Ready' bit in the response flag and sends an
> interrupt.
> 8. OPAL will receive the interrupt and queue the response to the host.
>
Hi Shilpasri,
Looks good!
I have a question about retries, from what I can see this allows
write_occ_cmd() to memcpy() no matter what, which sounds good, however,
you've called it 'retry' does that mean theres an expectation that the
caller wants to retry the same command? As far as I can tell the caller
could 'retry' anything.
Other comments inline.
> Signed-off-by: Shilpasri G Bhat <shilpa.bhat at linux.vnet.ibm.com>
> ---
> hw/occ.c | 453 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
> include/opal-api.h | 68 +++++++-
> 2 files changed, 516 insertions(+), 5 deletions(-)
>
> diff --git a/hw/occ.c b/hw/occ.c
> index 4be4df4..aa01bba 100644
> --- a/hw/occ.c
> +++ b/hw/occ.c
> @@ -119,6 +119,87 @@ struct occ_pstate_table {
> } __packed;
>
> /**
> + * OPAL-OCC Command Response Interface
> + *
> + * OPAL-OCC Command Buffer
> + *
> + * ---------------------------------------------------------------------
> + * | OPAL | Cmd | OPAL | | Cmd Data | Cmd Data | OPAL |
> + * | Cmd | Request | OCC | Reserved | Length | Length | Cmd |
> + * | Flags | ID | Cmd | | (MSB) | (LSB) | Data... |
> + * ---------------------------------------------------------------------
> + * | ….OPAL Command Data up to max of Cmd Data Length 4090 bytes |
> + * | |
> + * ---------------------------------------------------------------------
> + *
> + * OPAL Command Flag
> + *
> + * -----------------------------------------------------------------
> + * | Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
> + * | (msb) | | | | | | | (lsb) |
> + * -----------------------------------------------------------------
> + * |Cmd | | | | | | | |
> + * |Ready | | | | | | | |
> + * -----------------------------------------------------------------
> + *
> + * struct opal_command_buffer - Defines the layout of OPAL command buffer
> + * @flag: Provides general status of the command
> + * @request_id: Token to identify request
> + * @cmd: Command sent
> + * @data_size: Command data length
> + * @data: Command specific data
> + * @spare: Unused byte
> + */
> +struct opal_command_buffer {
> + u8 flag;
> + u8 request_id;
> + u8 cmd;
> + u8 spare;
> + u16 data_size;
> + u8 data[MAX_OPAL_CMD_DATA_LENGTH];
> +} __packed;
> +
> +/**
> + * OPAL-OCC Response Buffer
> + *
> + * ---------------------------------------------------------------------
> + * | OCC | Cmd | OPAL | Response | Rsp Data | Rsp Data | OPAL |
> + * | Rsp | Request | OCC | Status | Length | Length | Rsp |
> + * | Flags | ID | Cmd | | (MSB) | (LSB) | Data... |
> + * ---------------------------------------------------------------------
> + * | ….OPAL Response Data up to max of Rsp Data Length 8698 bytes |
> + * | |
> + * ---------------------------------------------------------------------
> + *
> + * OCC Response Flag
> + *
> + * -----------------------------------------------------------------
> + * | Bit 7 | Bit 6 | Bit 5 | Bit 4 | Bit 3 | Bit 2 | Bit 1 | Bit 0 |
> + * | (msb) | | | | | | | (lsb) |
> + * -----------------------------------------------------------------
> + * | | | | | | |OCC in | Rsp |
> + * | | | | | | |progress|Ready |
> + * -----------------------------------------------------------------
> + *
> + * struct occ_response_buffer - Defines the layout of OCC response buffer
> + * @flag: Provides general status of the response
> + * @request_id: Token to identify request
> + * @cmd: Command requested
> + * @status: Indicates success/failure status of
> + * the command
> + * @data_size: Response data length
> + * @data: Response specific data
> + */
> +struct occ_response_buffer {
> + u8 flag;
> + u8 request_id;
> + u8 cmd;
> + u8 status;
> + u16 data_size;
> + u8 data[MAX_OCC_RSP_DATA_LENGTH];
> +} __packed;
> +
> +/**
> * OCC-OPAL Shared Memory Interface Dynamic Data Vx90
> *
> * struct occ_dynamic_data - Contains runtime attributes
> @@ -135,6 +216,8 @@ struct occ_pstate_table {
> * @max_pwr_cap: Maximum allowed system power cap in Watts
> * @cur_pwr_cap: Current system power cap
> * @spare/reserved: Unused data
> + * @cmd: Opal Command Buffer
> + * @rsp: OCC Response Buffer
> */
> struct occ_dynamic_data {
> u8 occ_state;
> @@ -150,7 +233,9 @@ struct occ_dynamic_data {
> u16 min_pwr_cap;
> u16 max_pwr_cap;
> u16 cur_pwr_cap;
> - u64 reserved;
> + u8 pad[112];
> + struct opal_command_buffer cmd;
> + struct occ_response_buffer rsp;
> } __packed;
>
> static bool occ_reset;
> @@ -842,6 +927,363 @@ done:
> unlock(&occ_lock);
> }
>
> +#define OCC_RSP_READY 0x01
> +#define OCC_IN_PROGRESS 0x02
> +#define OPAL_CMD_READY 0x80
> +
> +enum occ_state {
> + OCC_STATE_NOT_RUNNING = 0x00,
> + OCC_STATE_STANDBY = 0x01,
> + OCC_STATE_OBSERVATION = 0x02,
> + OCC_STATE_ACTIVE = 0x03,
> + OCC_STATE_SAFE = 0x04,
> + OCC_STATE_CHAR = 0x05, /* Characterization */
Not to be confused with the type... I can't think of a better name...
> +};
> +
> +enum occ_role {
> + OCC_ROLE_SLAVE = 0x0,
> + OCC_ROLE_MASTER = 0x1,
> +};
> +
> +enum occ_cmd_value {
> + OCC_CMD_VALUE_AMESTER_PASS_THRU = 0x41,
> + OCC_CMD_VALUE_CLEAR_SENSOR_DATA = 0xD0,
> + OCC_CMD_VALUE_SET_POWER_CAP = 0xD1,
> + OCC_CMD_VALUE_SET_POWER_SHIFTING_RATIO = 0xD2,
> +};
> +
> +struct opal_occ_cmd_info {
> + enum occ_cmd_value value;
> + int timeout_ms;
> + u16 state_mask;
> + u8 role_mask;
> +};
> +
> +static struct opal_occ_cmd_info occ_cmds[] = {
> + { OCC_CMD_VALUE_AMESTER_PASS_THRU,
> + 1000,
> + PPC_BIT16(OCC_STATE_OBSERVATION) |
> + PPC_BIT16(OCC_STATE_ACTIVE) |
> + PPC_BIT16(OCC_STATE_CHAR),
> + PPC_BIT8(OCC_ROLE_MASTER) | PPC_BIT8(OCC_ROLE_SLAVE)
> + },
> + { OCC_CMD_VALUE_CLEAR_SENSOR_DATA,
> + 1000,
> + PPC_BIT16(OCC_STATE_OBSERVATION) |
> + PPC_BIT16(OCC_STATE_ACTIVE) |
> + PPC_BIT16(OCC_STATE_CHAR),
> + PPC_BIT8(OCC_ROLE_MASTER) | PPC_BIT8(OCC_ROLE_SLAVE)
> + },
> + { OCC_CMD_VALUE_SET_POWER_CAP,
> + 1000,
> + PPC_BIT16(OCC_STATE_OBSERVATION) |
> + PPC_BIT16(OCC_STATE_ACTIVE) |
> + PPC_BIT16(OCC_STATE_CHAR),
> + PPC_BIT8(OCC_ROLE_MASTER)
> + },
> + { OCC_CMD_VALUE_SET_POWER_SHIFTING_RATIO,
> + 1000,
> + PPC_BIT16(OCC_STATE_OBSERVATION) |
> + PPC_BIT16(OCC_STATE_ACTIVE) |
> + PPC_BIT16(OCC_STATE_CHAR),
> + PPC_BIT8(OCC_ROLE_MASTER) | PPC_BIT8(OCC_ROLE_SLAVE)
> + },
> +};
> +
> +static struct cmd_interface {
> + struct lock queue_lock;
> + struct timer timeout;
> + struct opal_command_buffer *cmd;
> + struct occ_response_buffer *rsp;
> + struct opal_occ_cmd_rsp_msg *msg;
> + u32 id;
> + u8 occ_role;
> + u8 *occ_state;
> + bool cmd_in_progress;
> +} *chips;
> +
> +struct occ_rsp_msg {
> + struct list_node link;
> + u8 token;
> + int rc;
> +};
> +
> +static LIST_HEAD(rsp_msg_list);
> +static struct lock rsp_msg_lock = LOCK_UNLOCKED;
> +static bool rsp_msg_in_use;
> +
> +static inline struct cmd_interface *get_chip_cmd_interface(int chip_id)
> +{
> + struct proc_chip *chip;
> + int i = 0;
> +
> + for_each_chip(chip) {
> + if (chips[i].id == chip_id)
> + return &chips[i];
> + i++;
> + }
> +
> + return NULL;
> +}
You seem to have abused the for_each_chip() macro to loop on your chips
structure. It should work, in the init your chips->id is equal to each
chip->id.
Would it not make more sense to store the size of your chips array so
that you can
for (i = 0; i < nr_chips; i++) {
instead of
for_each_chip(chip) {
Cyril
> +
> +static inline bool occ_in_progress(struct cmd_interface *chip)
> +{
> + return (chip->rsp->flag == OCC_IN_PROGRESS);
> +}
> +
> +static int write_occ_cmd(struct cmd_interface *chip, bool retry)
> +{
> + struct opal_command_buffer *cmd = chip->cmd;
> + struct opal_occ_cmd_rsp_msg *msg = chip->msg;
> +
> + if (!retry && occ_in_progress(chip)) {
> + chip->cmd_in_progress = false;
> + return OPAL_OCC_BUSY;
> + }
> +
> + cmd->flag = chip->rsp->flag = 0;
> + cmd->cmd = occ_cmds[msg->cmd].value;
> + cmd->request_id = msg->request_id;
> + cmd->data_size = msg->cdata_size;
> + memcpy(&cmd->data, msg->cdata, msg->cdata_size);
> + cmd->flag = OPAL_CMD_READY;
> +
> + schedule_timer(&chip->timeout,
> + msecs_to_tb(occ_cmds[msg->cmd].timeout_ms));
> +
> + return OPAL_ASYNC_COMPLETION;
> +}
> +
> +static int64_t opal_occ_command(int chip_id, struct opal_occ_cmd_rsp_msg *msg,
> + bool retry)
> +{
> + struct cmd_interface *chip;
> + int rc;
> +
> + if (!msg || !opal_addr_valid(msg->cdata) ||
> + !opal_addr_valid(msg->rdata))
> + return OPAL_PARAMETER;
> +
> + if (msg->cmd >= OCC_CMD_LAST)
> + return OPAL_UNSUPPORTED;
> +
> + if (msg->cdata_size > MAX_OPAL_CMD_DATA_LENGTH)
> + return OPAL_PARAMETER;
> +
> + chip = get_chip_cmd_interface(chip_id);
> + if (!chip)
> + return OPAL_PARAMETER;
> +
> + if (!(PPC_BIT8(chip->occ_role) & occ_cmds[msg->cmd].role_mask))
> + return OPAL_PARAMETER;
> +
> + if (!(PPC_BIT16(*chip->occ_state) & occ_cmds[msg->cmd].state_mask))
> + return OPAL_OCC_INVALID_STATE;
> +
> + lock(&chip->queue_lock);
> + if (chip->cmd_in_progress) {
> + rc = OPAL_OCC_BUSY;
> + goto out;
> + }
> +
> + chip->msg = msg;
> + chip->cmd_in_progress = true;
> + rc = write_occ_cmd(chip, retry);
> +out:
> + unlock(&chip->queue_lock);
> + return rc;
> +}
> +
> +static inline bool sanity_check_opal_cmd(struct opal_command_buffer *cmd,
> + struct opal_occ_cmd_rsp_msg *msg)
> +{
> + return ((cmd->cmd == occ_cmds[msg->cmd].value) &&
> + (cmd->request_id == msg->request_id) &&
> + (cmd->data_size == msg->cdata_size));
> +}
> +
> +static inline bool check_occ_rsp(struct opal_command_buffer *cmd,
> + struct occ_response_buffer *rsp)
> +{
> + if (cmd->cmd != rsp->cmd) {
> + prlog(PR_WARNING, "OCC: Command value mismatch in OCC response"
> + "rsp->cmd = %d cmd->cmd = %d\n", rsp->cmd, cmd->cmd);
> + return false;
> + }
> +
> + if (cmd->request_id != rsp->request_id) {
> + prlog(PR_WARNING, "OCC: Request ID mismatch in OCC response"
> + "rsp->request_id = %d cmd->request_id = %d\n",
> + rsp->request_id, cmd->request_id);
> + return false;
> + }
> +
> + return true;
> +}
> +
> +static void occ_rsp_msg_consumed(void *data __unused);
> +
> +static inline int queue_occ_rsp_msg(int token, int rc)
> +{
> + return opal_queue_msg(OPAL_MSG_ASYNC_COMP, NULL, occ_rsp_msg_consumed,
> + token, rc);
> +}
> +
> +static void occ_rsp_msg_consumed(void *data __unused)
> +{
> + struct occ_rsp_msg *item;
> +
> + lock(&rsp_msg_lock);
> +
> + /* Queue next message */
> + item = list_pop(&rsp_msg_list, struct occ_rsp_msg, link);
> + if (!item) {
> + rsp_msg_in_use = false;
> + goto exit;
> + }
> +
> + if (!queue_occ_rsp_msg(item->token, item->rc)) {
> + rsp_msg_in_use = true;
> + free(item);
> + } else {
> + rsp_msg_in_use = false;
> + list_add(&rsp_msg_list, &item->link);
> + }
> +exit:
> + unlock(&rsp_msg_lock);
> +}
> +
> +static void send_occ_rsp_msg(u8 token, int rc)
> +{
> + struct occ_rsp_msg *item;
> +
> + lock(&rsp_msg_lock);
> + if (!rsp_msg_in_use && !queue_occ_rsp_msg(token, rc)) {
> + rsp_msg_in_use = true;
> + goto out;
> + }
> +
> + item = malloc(sizeof(*item));
> + if (!item)
> + goto out;
> +
> + item->token = token;
> + item->rc = rc;
> + item->link.next = item->link.prev = NULL;
> + list_add_tail(&rsp_msg_list, &item->link);
> +out:
> + unlock(&rsp_msg_lock);
> +}
> +
> +static void occ_cmd_timeout_handler(struct timer *t __unused, void *data,
> + uint64_t now __unused)
> +{
> + struct cmd_interface *chip = data;
> +
> + lock(&chip->queue_lock);
> + if (!chip->cmd_in_progress)
> + goto exit;
> +
> + chip->cmd_in_progress = false;
> + send_occ_rsp_msg(chip->msg->request_id, OPAL_OCC_CMD_TIMEOUT);
> +exit:
> + unlock(&chip->queue_lock);
> +}
> +
> +static void read_occ_rsp(struct occ_response_buffer *rsp,
> + struct opal_occ_cmd_rsp_msg *msg)
> +{
> + /* Copy response to host buffer */
> + msg->status = rsp->status;
> + msg->rdata_size = rsp->data_size;
> + memcpy(msg->rdata, rsp->data, rsp->data_size);
> +
> + /* Clear the OCC response flag */
> + rsp->flag = 0;
> +}
> +
> +static void handle_occ_rsp(uint32_t chip_id)
> +{
> + struct cmd_interface *chip;
> + struct opal_command_buffer *cmd;
> + struct occ_response_buffer *rsp;
> + struct opal_occ_cmd_rsp_msg *msg;
> +
> + chip = get_chip_cmd_interface(chip_id);
> + if (!chip)
> + return;
> +
> + cmd = chip->cmd;
> + rsp = chip->rsp;
> + msg = chip->msg;
> +
> + /*Read rsp*/
> + if (rsp->flag != OCC_RSP_READY)
> + return;
> + lock(&chip->queue_lock);
> + if (!chip->cmd_in_progress)
> + goto exit;
> +
> + chip->cmd_in_progress = false;
> + cancel_timer(&chip->timeout);
> + if (!sanity_check_opal_cmd(cmd, chip->msg) ||
> + !check_occ_rsp(cmd, rsp)) {
> + send_occ_rsp_msg(msg->request_id, OPAL_OCC_CMD_MISMATCH);
> + goto exit;
> + }
> +
> + read_occ_rsp(chip->rsp, msg);
> + send_occ_rsp_msg(msg->request_id, OPAL_SUCCESS);
> +exit:
> + unlock(&chip->queue_lock);
> +}
> +
> +static void occ_cmd_interface_init(void)
> +{
> + struct dt_node *power_mgt;
> + struct occ_dynamic_data *data;
> + struct occ_pstate_table *pdata;
> + struct proc_chip *chip;
> + int i = 0, nr_chips = 0;
> +
> + chip = next_chip(NULL);
> + pdata = get_occ_pstate_table(chip);
> + if (pdata->version != 0x90)
> + return;
> +
> + for_each_chip(chip)
> + nr_chips++;
> +
> + chips = malloc(sizeof(*chips) * nr_chips);
> + assert(chips);
> +
> + for_each_chip(chip) {
> + pdata = get_occ_pstate_table(chip);
> + data = get_occ_dynamic_data(chip);
> + chips[i].id = chip->id;
> + chips[i].occ_role = pdata->v9.occ_role;
> + chips[i].occ_state = &data->occ_state;
> + chips[i].cmd = &data->cmd;
> + chips[i].rsp = &data->rsp;
> + init_lock(&chips[i].queue_lock);
> + chips[i].cmd_in_progress = false;
> + init_timer(&chips[i].timeout, occ_cmd_timeout_handler,
> + &chips[i]);
> + i++;
> + }
> +
> + power_mgt = dt_find_by_path(dt_root, "/ibm,opal/power-mgt");
> + if (!power_mgt) {
> + prerror("OCC: dt node /ibm,opal/power-mgt not found\n");
> + free(chips);
> + return;
> + }
> +
> + dt_add_property_string(power_mgt, "compatible",
> + "ibm,opal-occ-cmd-rsp-interface");
> + opal_register(OPAL_OCC_COMMAND, opal_occ_command, 3);
> +}
> +
> /* CPU-OCC PState init */
> /* Called after OCC init on P8 and P9 */
> void occ_pstates_init(void)
> @@ -909,6 +1351,9 @@ void occ_pstates_init(void)
> chip->throttle = 0;
> opal_add_poller(occ_throttle_poll, NULL);
> occ_pstates_initialized = true;
> +
> + /* Init OPAL-OCC command-response interface */
> + occ_cmd_interface_init();
> }
>
> struct occ_load_req {
> @@ -1394,8 +1839,10 @@ void occ_p9_interrupt(uint32_t chip_id)
> if (ireg & OCB_OCI_OCIMISC_IRQ_TMGT)
> prd_tmgt_interrupt(chip_id);
>
> - if (ireg & OCB_OCI_OCIMISC_IRQ_SHMEM)
> + if (ireg & OCB_OCI_OCIMISC_IRQ_SHMEM) {
> occ_throttle_poll(NULL);
> + handle_occ_rsp(chip_id);
> + }
>
> /* We may have masked-out OCB_OCI_OCIMISC_IRQ in the previous
> * OCCMISC_AND write. Check if there are any new source bits set,
> @@ -1417,5 +1864,3 @@ void occ_fsp_init(void)
> if (fsp_present())
> fsp_register_client(&fsp_occ_client, FSP_MCLASS_OCC);
> }
> -
> -
> diff --git a/include/opal-api.h b/include/opal-api.h
> index 80033c6..4acbd44 100644
> --- a/include/opal-api.h
> +++ b/include/opal-api.h
> @@ -55,6 +55,10 @@
> #define OPAL_XSCOM_CTR_OFFLINED -30
> #define OPAL_XIVE_PROVISIONING -31
> #define OPAL_XIVE_FREE_ACTIVE -32
> +#define OPAL_OCC_INVALID_STATE -33
> +#define OPAL_OCC_BUSY -34
> +#define OPAL_OCC_CMD_TIMEOUT -35
> +#define OPAL_OCC_CMD_MISMATCH -36
>
> /* API Tokens (in r0) */
> #define OPAL_INVALID_CALL -1
> @@ -204,7 +208,8 @@
> #define OPAL_NPU_INIT_CONTEXT 146
> #define OPAL_NPU_DESTROY_CONTEXT 147
> #define OPAL_NPU_MAP_LPAR 148
> -#define OPAL_LAST 148
> +#define OPAL_OCC_COMMAND 149
> +#define OPAL_LAST 149
>
> /* Device tree flags */
>
> @@ -1021,6 +1026,67 @@ typedef struct oppanel_line {
> __be64 line_len;
> } oppanel_line_t;
>
> +enum occ_cmd {
> + OCC_CMD_AMESTER_PASS_THRU = 0,
> + OCC_CMD_CLEAR_SENSOR_DATA,
> + OCC_CMD_SET_POWER_CAP,
> + OCC_CMD_SET_POWER_SHIFTING_RATIO,
> + OCC_CMD_LAST
> +};
> +
> +enum occ_cmd_data_length {
> + OCC_CMD_DL_AMESTER_PASS_THRU = 0, /* Variable data length */
> + OCC_CMD_DL_CLEAR_SENSOR_DATA = 4,
> + OCC_CMD_DL_SET_POWER_CAP = 2,
> + OCC_CMD_DL_SET_POWER_SHIFTING_RATIO = 1,
> +};
> +
> +enum occ_rsp_data_length {
> + OCC_RSP_DL_AMESTER_PASS_THRU = 0, /* Variable data length */
> + OCC_RSP_DL_CLEAR_SENSOR_DATA = 4,
> + OCC_RSP_DL_SET_POWER_CAP = 2,
> + OCC_RSP_DL_SET_POWER_SHIFTING_RATIO = 1,
> +};
> +
> +enum occ_sensor_limit_group {
> + OCC_SENSOR_LIMIT_GROUP_CSM = 0x10,
> + OCC_SENSOR_LIMIT_GROUP_PROFILER = 0x20,
> + OCC_SENSOR_LIMIT_GROUP_JOB_SCHED = 0x30,
> +};
> +
> +#define MAX_OPAL_CMD_DATA_LENGTH 4090
> +#define MAX_OCC_RSP_DATA_LENGTH 8698
> +
> +enum occ_response_status {
> + OCC_SUCCESS = 0x00,
> + OCC_INVALID_COMMAND = 0x11,
> + OCC_INVALID_CMD_DATA_LENGTH = 0x12,
> + OCC_INVALID_DATA = 0x13,
> + OCC_INTERNAL_ERROR = 0x15,
> +};
> +
> +struct opal_occ_cmd_rsp_msg {
> + u8 *cdata;
> + u8 *rdata;
> + __be16 cdata_size;
> + __be16 rdata_size;
> + u8 cmd;
> + u8 request_id;
> + u8 status;
> +};
> +
> +struct opal_occ_cmd_data {
> + u16 size;
> + u8 cmd;
> + u8 data[];
> +};
> +
> +struct opal_occ_rsp_data {
> + u16 size;
> + u8 status;
> + u8 data[];
> +};
> +
> enum opal_prd_msg_type {
> OPAL_PRD_MSG_TYPE_INIT = 0, /* HBRT --> OPAL */
> OPAL_PRD_MSG_TYPE_FINI, /* HBRT/kernel --> OPAL */
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