Messages in this thread Patch in this message | | | Date | Mon, 10 Oct 2022 12:08:24 +0100 | Subject | Re: [PATCH v10 1/3] ipmi: ssif_bmc: Add SSIF BMC driver | From | Graeme Gregory <> |
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On 10/10/2022 02:28, Quan Nguyen wrote: > > > On 07/10/2022 20:26, Graeme Gregory wrote: >> >> On 04/10/2022 10:31, Quan Nguyen wrote: >>> The SMBus system interface (SSIF) IPMI BMC driver can be used to >>> perform >>> in-band IPMI communication with their host in management (BMC) side. >>> >>> Thanks Dan for the copy_from_user() fix in the link below. >>> >>> Link: >>> https://lore.kernel.org/linux-arm-kernel/20220310114119.13736-4-quan@os.amperecomputing.com/ >>> Signed-off-by: Quan Nguyen <quan@os.amperecomputing.com> >> >> I have been testing this on our hardware and I don't seem to be able >> to get this driver working. I was using an older version. >> >> I have hacked ssifbridged to deal with the change in len from u8 to >> unsigned int. >> >> It works as long as I only ever send SSIF commands, any attempt to >> read a response crashes the state machine and the driver never >> recovers. No further SSIF comms is possible! (slave doesnt even ACK >> writes). >> >> A couple of comments below on possible state machine errors. >> >> Its possible I am doing something wrong! >> > > Thanks Graeme for the test and the comments. > > What's your testing hardware? > > This was tested with Aspeed ast2500 and ast2600 with the patch series > [1] below applied. > > If you use the same hw, could you pick the series and see if any thing > improve ? > > [1] > https://lore.kernel.org/all/20210616031046.2317-1-quan@os.amperecomputing.com/ > Thanks, that patch series does stop the state machine crashing.
I am testing on AST2600EVB with A1 rev, but we also have our own DC-SCM with A3 chip.
Responses are still not working for me, but I think that may be an error in my ssifbridged hacks.
Oct 10 10:54:55 qcom-evb-proto-ccf37d18ea0c ssifbridged[335]: Read ssif request message with len=13 netfn=44 lun=0 cmd=2
Oct 10 10:54:55 qcom-evb-proto-ccf37d18ea0c ipmid[312]: BootCode: 000000000000000000
Oct 10 10:54:55 qcom-evb-proto-ccf37d18ea0c ssifbridged[335]: Send ssif respond message with len=4 netfn=45 lun=0 cmd=2 cc=0
Oct 10 10:54:55 qcom-evb-proto-ccf37d18ea0c kernel: ipmi-ssif-host 0-0010: Warn: on_read_requested_event unexpected READ REQUESTED in state=SSIF_READY
Oct 10 10:54:55 qcom-evb-proto-ccf37d18ea0c kernel: ipmi-ssif-host 0-0010: Warn: on_stop_event unexpected SLAVE STOP in state=SSIF_ABORTING
>>> --- >>> v10: >>> + None >>> >>> v9: >>> + Fix dependence with I2C subsystem >>> [Randy] >>> + Remove useless error handling path >>> [CJ] >>> + Update comment for SSIF_ABORTING state >>> [CJ] >>> + Fix "unknown type name --u8" [kernel test >>> robot] >>> + Fix ssif_bmc_remove() to return void to align with recent kernel >>> change [Quan] >>> >>> v8: >>> + Dropped ssif_bmc.h file and move its content to ssif_bmc.c >>> [Corey] >>> + Add struct ipmi_ssif_msg to include/uapi/linux/ipmi_ssif_bmc.h >>> header file [Corey] >>> + Use unsigned int for len field in struct ipmi_ssif_msg >>> [Corey] >>> + Avoid using packed structure >>> [Corey] >>> + Add comment to clarify the logic flow >>> [Corey] >>> + Fix multipart read end with len=0 issue >>> [Corey] >>> + Refactor code handle the too big request message >>> [Corey] >>> + Fix code indentation issue >>> [Corey] >>> + Clean buffer before receiving request to avoid garbage >>> [Quan] >>> + Fix the license to SPDX-License-Identifier: GPL-2.0-only >>> [Quan] >>> >>> v7: >>> + Remove unneccessary del_timer() in response_timeout() >>> [Corey] >>> + Change compatible string from "ampere,ssif-bmc" to "ssif-bmc" >>> [Jae] >>> + Add MODULE_DEVICE_TABLE(of, ssif_bmc_match), fix blank line >>> [Jae] >>> + Dropped the use of ssif_msg_len() macro, use the len directly >>> [Quan] >>> + Solve possible issue if both response timer and ssif_bmc_write() >>> occurred at the same time >>> [Corey] >>> + Fix wrong return type of ssif_bmc_poll() [kernel robot >>> test] >>> + Refactor and introduce ssif_part_buffer struct to replace the >>> response_buf to manage each send/receive part of ssif >>> [Quan] >>> + Change SSIF_BAD_SMBUS state to SSIF_ABORTING state >>> [Corey] >>> + Support abort feature to skip the current bad request/response and >>> wait until next new request >>> [Corey] >>> + Refactor the PEC calculation to avoid the re-calculate the PEC on >>> each I2C_SLAVE_WRITE_RECEIVED event >>> [Quan] >>> + Fix the use of error-proned idx >>> [Corey] >>> + Defer the test for valid SMBus command until the read/write part >>> is determined [Quan] >>> + Change/split unsupported_smbus_cmd() to >>> supported_[write|read]_cmd() [Corey] >>> + Abort the request if somehow its size exceeded 255 bytes >>> [Quan] >>> >>> v6: >>> + Drop the use of slave_enable() >>> [Wolfram] >>> + Make i2c-aspeed to issue RxCmdLast command on all >>> I2C_SLAVE_WRITE_REQUESTED event to assert NAK when slave busy >>> [Quan] >>> + Make i2c slave to return -EBUSY when it's busy >>> [Quan] >>> + Drop the aborting feature as return Completion Code 0xFF may stop >>> host to retry and make ipmi_ssif.so fails to load >>> [Quan] >>> + Add timer to recover slave from busy state when no response >>> [Quan] >>> + Clean request/response buffer appropriately >>> [Quan] >>> + Add some minor change on error and warning messages >>> [Quan] >>> >>> v5: >>> + None >>> >>> v4: >>> + Send response with Completion code 0xFF when aborting >>> [Quan] >>> + Added bounding check on SMBus writes and the whole request >>> [Dan] >>> + Moved buffer to end of struct ssif_bmc_ctx to avoid context >>> corruption if somehow buffer is written past the end >>> [Dan] >>> + Return -EINVAL if userspace buffer too small, dont >>> silence truncate [Corey, Joel] >>> + Not necessary to check NONBLOCK in lock >>> [Corey] >>> + Enforce one user at a time >>> [Joel] >>> + Reject write with invalid response length from userspace >>> [Corey] >>> + Add state machines for better ssif bmc state handling >>> [Quan] >>> + Drop ssif_bmc_aspeed.c and make ssif_bmc.c is generic >>> SSIF BMC driver >>> [Quan] >>> + Change compatible string "aspeed,ast2500-ssif-bmc" to >>> "ampere,ssif-bmc" [Quan] >>> + Abort current request with invalid SMBus write or >>> invalid command >>> [Quan] >>> + Abort all request if there is pending response >>> [Quan] >>> + Changed validate_pec() to validate_request() >>> [Quan] >>> + Add unsupported_smbus_cmd() to handle unknown SMBus command >>> [Quan] >>> + Print internal state string for ease investigating issue >>> [Quan] >>> + Move to READY state on SLAVE_STOP event >>> [Quan] >>> + Change initilize_transfer() to process_smbus_cmd() >>> [Quan] >>> + Introduce functions for each slave event >>> [Quan] >>> >>> v3: >>> + Removed redundant license info >>> [Joel] >>> + Switched to use traditional if-else >>> [Joel] >>> + Removed unused ssif_bmc_ioctl() >>> [Joel] >>> + Made handle_request()/complete_response() to return void >>> [Joel] >>> + Refactored send_ssif_bmc_response() and >>> receive_ssif_bmc_request() [Corey] >>> + Removed mutex >>> [Corey] >>> + Use spin_lock/unlock_irqsave/restore in callback >>> [Corey] >>> + Removed the unnecessary memset >>> [Corey] >>> + Switch to use dev_err() >>> [Corey] >>> >>> v2: >>> + Fixed compiling error with COMPILE_TEST for arc >>> --- >>> drivers/char/ipmi/Kconfig | 10 + >>> drivers/char/ipmi/Makefile | 1 + >>> drivers/char/ipmi/ssif_bmc.c | 873 >>> +++++++++++++++++++++++++++++ >>> include/uapi/linux/ipmi_ssif_bmc.h | 18 + >>> 4 files changed, 902 insertions(+) >>> create mode 100644 drivers/char/ipmi/ssif_bmc.c >>> create mode 100644 include/uapi/linux/ipmi_ssif_bmc.h >>> >>> diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig >>> index 39565cf74b2c..b6c0d35fc1a5 100644 >>> --- a/drivers/char/ipmi/Kconfig >>> +++ b/drivers/char/ipmi/Kconfig >>> @@ -169,6 +169,16 @@ config ASPEED_BT_IPMI_BMC >>> found on Aspeed SOCs (AST2400 and AST2500). The driver >>> implements the BMC side of the BT interface. >>> +config SSIF_IPMI_BMC >>> + tristate "SSIF IPMI BMC driver" >>> + depends on I2C && I2C_SLAVE >>> + help >>> + This enables the IPMI SMBus system interface (SSIF) at the >>> + management (BMC) side. >>> + >>> + The driver implements the BMC side of the SMBus system >>> + interface (SSIF). >>> + >>> config IPMB_DEVICE_INTERFACE >>> tristate 'IPMB Interface handler' >>> depends on I2C >>> diff --git a/drivers/char/ipmi/Makefile b/drivers/char/ipmi/Makefile >>> index 7ce790efad92..cb6138b8ded9 100644 >>> --- a/drivers/char/ipmi/Makefile >>> +++ b/drivers/char/ipmi/Makefile >>> @@ -30,3 +30,4 @@ obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o >>> obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o >>> obj-$(CONFIG_NPCM7XX_KCS_IPMI_BMC) += kcs_bmc_npcm7xx.o >>> obj-$(CONFIG_IPMB_DEVICE_INTERFACE) += ipmb_dev_int.o >>> +obj-$(CONFIG_SSIF_IPMI_BMC) += ssif_bmc.o >>> diff --git a/drivers/char/ipmi/ssif_bmc.c >>> b/drivers/char/ipmi/ssif_bmc.c >>> new file mode 100644 >>> index 000000000000..a7bb4b99000e >>> --- /dev/null >>> +++ b/drivers/char/ipmi/ssif_bmc.c >>> @@ -0,0 +1,873 @@ >>> +// SPDX-License-Identifier: GPL-2.0-only >>> +/* >>> + * The driver for BMC side of SSIF interface >>> + * >>> + * Copyright (c) 2022, Ampere Computing LLC >>> + * >>> + */ >>> + >>> +#include <linux/i2c.h> >>> +#include <linux/miscdevice.h> >>> +#include <linux/module.h> >>> +#include <linux/of.h> >>> +#include <linux/platform_device.h> >>> +#include <linux/poll.h> >>> +#include <linux/sched.h> >>> +#include <linux/mutex.h> >>> +#include <linux/spinlock.h> >>> +#include <linux/timer.h> >>> +#include <linux/jiffies.h> >>> +#include <linux/ipmi_ssif_bmc.h> >>> + >>> +#define DEVICE_NAME "ipmi-ssif-host" >>> + >>> +#define GET_8BIT_ADDR(addr_7bit) (((addr_7bit) << 1) >>> & 0xff) >>> + >>> +/* A standard SMBus Transaction is limited to 32 data bytes */ >>> +#define MAX_PAYLOAD_PER_TRANSACTION 32 >>> +/* Transaction includes the address, the command, the length and >>> the PEC byte */ >>> +#define MAX_TRANSACTION (MAX_PAYLOAD_PER_TRANSACTION + 4) >>> + >>> +#define MAX_IPMI_DATA_PER_START_TRANSACTION 30 >>> +#define MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION 31 >>> + >>> +#define SSIF_IPMI_SINGLEPART_WRITE 0x2 >>> +#define SSIF_IPMI_SINGLEPART_READ 0x3 >>> +#define SSIF_IPMI_MULTIPART_WRITE_START 0x6 >>> +#define SSIF_IPMI_MULTIPART_WRITE_MIDDLE 0x7 >>> +#define SSIF_IPMI_MULTIPART_WRITE_END 0x8 >>> +#define SSIF_IPMI_MULTIPART_READ_START 0x3 >>> +#define SSIF_IPMI_MULTIPART_READ_MIDDLE 0x9 >>> + >>> +/* >>> + * IPMI 2.0 Spec, section 12.7 SSIF Timing, >>> + * Request-to-Response Time is T6max(250ms) - T1max(20ms) - 3ms = >>> 227ms >>> + * Recover ssif_bmc from busy state if it takes up to 500ms >>> + */ >>> +#define RESPONSE_TIMEOUT 500 /* ms */ >>> + >>> +struct ssif_part_buffer { >>> + u8 address; >>> + u8 smbus_cmd; >>> + u8 length; >>> + u8 payload[MAX_PAYLOAD_PER_TRANSACTION]; >>> + u8 pec; >>> + u8 index; >>> +}; >>> + >>> +/* >>> + * SSIF internal states: >>> + * SSIF_READY 0x00 : Ready state >>> + * SSIF_START 0x01 : Start smbus transaction >>> + * SSIF_SMBUS_CMD 0x02 : Received SMBus command >>> + * SSIF_REQ_RECVING 0x03 : Receiving request >>> + * SSIF_RES_SENDING 0x04 : Sending response >>> + * SSIF_ABORTING 0x05 : Aborting state >>> + */ >>> +enum ssif_state { >>> + SSIF_READY, >>> + SSIF_START, >>> + SSIF_SMBUS_CMD, >>> + SSIF_REQ_RECVING, >>> + SSIF_RES_SENDING, >>> + SSIF_ABORTING, >>> + SSIF_STATE_MAX >>> +}; >>> + >>> +struct ssif_bmc_ctx { >>> + struct i2c_client *client; >>> + struct miscdevice miscdev; >>> + int msg_idx; >>> + bool pec_support; >>> + /* ssif bmc spinlock */ >>> + spinlock_t lock; >>> + wait_queue_head_t wait_queue; >>> + u8 running; >>> + enum ssif_state state; >>> + /* Timeout waiting for response */ >>> + struct timer_list response_timer; >>> + bool response_timer_inited; >>> + /* Flag to identify a Multi-part Read Transaction */ >>> + bool is_singlepart_read; >>> + u8 nbytes_processed; >>> + u8 remain_len; >>> + u8 recv_len; >>> + /* Block Number of a Multi-part Read Transaction */ >>> + u8 block_num; >>> + bool request_available; >>> + bool response_in_progress; >>> + bool busy; >>> + bool aborting; >>> + /* Buffer for SSIF Transaction part*/ >>> + struct ssif_part_buffer part_buf; >>> + struct ipmi_ssif_msg response; >>> + struct ipmi_ssif_msg request; >>> +}; >>> + >>> +static inline struct ssif_bmc_ctx *to_ssif_bmc(struct file *file) >>> +{ >>> + return container_of(file->private_data, struct ssif_bmc_ctx, >>> miscdev); >>> +} >>> + >>> +static const char *state_to_string(enum ssif_state state) >>> +{ >>> + switch (state) { >>> + case SSIF_READY: >>> + return "SSIF_READY"; >>> + case SSIF_START: >>> + return "SSIF_START"; >>> + case SSIF_SMBUS_CMD: >>> + return "SSIF_SMBUS_CMD"; >>> + case SSIF_REQ_RECVING: >>> + return "SSIF_REQ_RECVING"; >>> + case SSIF_RES_SENDING: >>> + return "SSIF_RES_SENDING"; >>> + case SSIF_ABORTING: >>> + return "SSIF_ABORTING"; >>> + default: >>> + return "SSIF_STATE_UNKNOWN"; >>> + } >>> +} >>> + >>> +/* Handle SSIF message that will be sent to user */ >>> +static ssize_t ssif_bmc_read(struct file *file, char __user *buf, >>> size_t count, loff_t *ppos) >>> +{ >>> + struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); >>> + struct ipmi_ssif_msg msg; >>> + unsigned long flags; >>> + ssize_t ret; >>> + >>> + spin_lock_irqsave(&ssif_bmc->lock, flags); >>> + while (!ssif_bmc->request_available) { >>> + spin_unlock_irqrestore(&ssif_bmc->lock, flags); >>> + if (file->f_flags & O_NONBLOCK) >>> + return -EAGAIN; >>> + ret = wait_event_interruptible(ssif_bmc->wait_queue, >>> + ssif_bmc->request_available); >>> + if (ret) >>> + return ret; >>> + spin_lock_irqsave(&ssif_bmc->lock, flags); >>> + } >>> + >>> + if (count < min_t(ssize_t, >>> + sizeof_field(struct ipmi_ssif_msg, len) + >>> ssif_bmc->request.len, >>> + sizeof(struct ipmi_ssif_msg))) { >>> + spin_unlock_irqrestore(&ssif_bmc->lock, flags); >>> + ret = -EINVAL; >>> + } else { >>> + count = min_t(ssize_t, >>> + sizeof_field(struct ipmi_ssif_msg, len) + >>> ssif_bmc->request.len, >>> + sizeof(struct ipmi_ssif_msg)); >>> + memcpy(&msg, &ssif_bmc->request, count); >>> + ssif_bmc->request_available = false; >>> + spin_unlock_irqrestore(&ssif_bmc->lock, flags); >>> + >>> + ret = copy_to_user(buf, &msg, count); >>> + } >>> + >>> + return (ret < 0) ? ret : count; >>> +} >>> + >>> +/* Handle SSIF message that is written by user */ >>> +static ssize_t ssif_bmc_write(struct file *file, const char __user >>> *buf, size_t count, >>> + loff_t *ppos) >>> +{ >>> + struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); >>> + struct ipmi_ssif_msg msg; >>> + unsigned long flags; >>> + ssize_t ret; >>> + >>> + if (count > sizeof(struct ipmi_ssif_msg)) >>> + return -EINVAL; >>> + >>> + if (copy_from_user(&msg, buf, count)) >>> + return -EFAULT; >>> + >>> + if (!msg.len || count < sizeof_field(struct ipmi_ssif_msg, len) >>> + msg.len) >>> + return -EINVAL; >>> + >>> + spin_lock_irqsave(&ssif_bmc->lock, flags); >>> + while (ssif_bmc->response_in_progress) { >>> + spin_unlock_irqrestore(&ssif_bmc->lock, flags); >>> + if (file->f_flags & O_NONBLOCK) >>> + return -EAGAIN; >>> + ret = wait_event_interruptible(ssif_bmc->wait_queue, >>> + !ssif_bmc->response_in_progress); >>> + if (ret) >>> + return ret; >>> + spin_lock_irqsave(&ssif_bmc->lock, flags); >>> + } >>> + >>> + /* >>> + * The write must complete before the response timeout fired, >>> otherwise >>> + * the response is aborted and wait for next request >>> + * Return -EINVAL if the response is aborted >>> + */ >>> + ret = (ssif_bmc->response_timer_inited) ? 0 : -EINVAL; >>> + if (ret) >>> + goto exit; >>> + >>> + del_timer(&ssif_bmc->response_timer); >>> + ssif_bmc->response_timer_inited = false; >>> + >>> + memcpy(&ssif_bmc->response, &msg, count); >>> + ssif_bmc->is_singlepart_read = (msg.len <= >>> MAX_PAYLOAD_PER_TRANSACTION); >>> + >>> + ssif_bmc->response_in_progress = true; >>> + >>> + /* ssif_bmc not busy */ >>> + ssif_bmc->busy = false; >>> + >>> + /* Clean old request buffer */ >>> + memset(&ssif_bmc->request, 0, sizeof(struct ipmi_ssif_msg)); >>> +exit: >>> + spin_unlock_irqrestore(&ssif_bmc->lock, flags); >>> + >>> + return (ret < 0) ? ret : count; >>> +} >>> + >>> +static int ssif_bmc_open(struct inode *inode, struct file *file) >>> +{ >>> + struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); >>> + int ret = 0; >>> + >>> + spin_lock_irq(&ssif_bmc->lock); >>> + if (!ssif_bmc->running) >>> + ssif_bmc->running = 1; >>> + else >>> + ret = -EBUSY; >>> + spin_unlock_irq(&ssif_bmc->lock); >>> + >>> + return ret; >>> +} >>> + >>> +static __poll_t ssif_bmc_poll(struct file *file, poll_table *wait) >>> +{ >>> + struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); >>> + __poll_t mask = 0; >>> + >>> + poll_wait(file, &ssif_bmc->wait_queue, wait); >>> + >>> + spin_lock_irq(&ssif_bmc->lock); >>> + /* The request is available, userspace application can get the >>> request */ >>> + if (ssif_bmc->request_available) >>> + mask |= POLLIN; >>> + >>> + spin_unlock_irq(&ssif_bmc->lock); >>> + >>> + return mask; >>> +} >>> + >>> +static int ssif_bmc_release(struct inode *inode, struct file *file) >>> +{ >>> + struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file); >>> + >>> + spin_lock_irq(&ssif_bmc->lock); >>> + ssif_bmc->running = 0; >>> + spin_unlock_irq(&ssif_bmc->lock); >>> + >>> + return 0; >>> +} >>> + >>> +/* >>> + * System calls to device interface for user apps >>> + */ >>> +static const struct file_operations ssif_bmc_fops = { >>> + .owner = THIS_MODULE, >>> + .open = ssif_bmc_open, >>> + .read = ssif_bmc_read, >>> + .write = ssif_bmc_write, >>> + .release = ssif_bmc_release, >>> + .poll = ssif_bmc_poll, >>> +}; >>> + >>> +/* Called with ssif_bmc->lock held. */ >>> +static void complete_response(struct ssif_bmc_ctx *ssif_bmc) >>> +{ >>> + /* Invalidate response in buffer to denote it having been sent. */ >>> + ssif_bmc->response.len = 0; >>> + ssif_bmc->response_in_progress = false; >>> + ssif_bmc->nbytes_processed = 0; >>> + ssif_bmc->remain_len = 0; >>> + ssif_bmc->busy = false; >>> + memset(&ssif_bmc->part_buf, 0, sizeof(struct ssif_part_buffer)); >>> + wake_up_all(&ssif_bmc->wait_queue); >>> +} >>> + >>> +static void response_timeout(struct timer_list *t) >>> +{ >>> + struct ssif_bmc_ctx *ssif_bmc = from_timer(ssif_bmc, t, >>> response_timer); >>> + unsigned long flags; >>> + >>> + spin_lock_irqsave(&ssif_bmc->lock, flags); >>> + >>> + /* Do nothing if the response is in progress */ >>> + if (!ssif_bmc->response_in_progress) { >>> + /* Recover ssif_bmc from busy */ >>> + ssif_bmc->busy = false; >>> + ssif_bmc->response_timer_inited = false; >>> + /* Set aborting flag */ >>> + ssif_bmc->aborting = true; >>> + } >>> + >>> + spin_unlock_irqrestore(&ssif_bmc->lock, flags); >>> +} >>> + >>> +/* Called with ssif_bmc->lock held. */ >>> +static void handle_request(struct ssif_bmc_ctx *ssif_bmc) >>> +{ >>> + /* set ssif_bmc to busy waiting for response */ >>> + ssif_bmc->busy = true; >>> + /* Request message is available to process */ >>> + ssif_bmc->request_available = true; >>> + /* Clean old response buffer */ >>> + memset(&ssif_bmc->response, 0, sizeof(struct ipmi_ssif_msg)); >>> + /* This is the new READ request.*/ >>> + wake_up_all(&ssif_bmc->wait_queue); >>> + >>> + /* Armed timer to recover slave from busy state in case of no >>> response */ >>> + if (!ssif_bmc->response_timer_inited) { >>> + timer_setup(&ssif_bmc->response_timer, response_timeout, 0); >>> + ssif_bmc->response_timer_inited = true; >>> + } >>> + mod_timer(&ssif_bmc->response_timer, jiffies + >>> msecs_to_jiffies(RESPONSE_TIMEOUT)); >>> +} >>> + >>> +static void calculate_response_part_pec(struct ssif_part_buffer *part) >>> +{ >>> + u8 addr = part->address; >>> + >>> + /* PEC - Start Read Address */ >>> + part->pec = i2c_smbus_pec(0, &addr, 1); >>> + /* PEC - SSIF Command */ >>> + part->pec = i2c_smbus_pec(part->pec, &part->smbus_cmd, 1); >>> + /* PEC - Restart Write Address */ >>> + addr = addr | 0x01; >>> + part->pec = i2c_smbus_pec(part->pec, &addr, 1); >>> + part->pec = i2c_smbus_pec(part->pec, &part->length, 1); >>> + if (part->length) >>> + part->pec = i2c_smbus_pec(part->pec, part->payload, >>> part->length); >>> +} >>> + >>> +static void set_singlepart_response_buffer(struct ssif_bmc_ctx >>> *ssif_bmc) >>> +{ >>> + struct ssif_part_buffer *part = &ssif_bmc->part_buf; >>> + >>> + part->address = GET_8BIT_ADDR(ssif_bmc->client->addr); >>> + part->length = (u8)ssif_bmc->response.len; >>> + >>> + /* Clear the rest to 0 */ >>> + memset(part->payload + part->length, 0, >>> MAX_PAYLOAD_PER_TRANSACTION - part->length); >>> + memcpy(&part->payload[0], &ssif_bmc->response.payload[0], >>> part->length); >>> +} >>> + >>> +static void set_multipart_response_buffer(struct ssif_bmc_ctx >>> *ssif_bmc) >>> +{ >>> + struct ssif_part_buffer *part = &ssif_bmc->part_buf; >>> + u8 part_len = 0; >>> + >>> + part->address = GET_8BIT_ADDR(ssif_bmc->client->addr); >>> + switch (part->smbus_cmd) { >>> + case SSIF_IPMI_MULTIPART_READ_START: >>> + /* >>> + * Read Start length is 32 bytes. >>> + * Read Start transfer first 30 bytes of IPMI response >>> + * and 2 special code 0x00, 0x01. >>> + */ >>> + ssif_bmc->nbytes_processed = 0; >>> + ssif_bmc->block_num = 0; >>> + part->length = MAX_PAYLOAD_PER_TRANSACTION; >>> + part_len = MAX_IPMI_DATA_PER_START_TRANSACTION; >>> + ssif_bmc->remain_len = ssif_bmc->response.len - part_len; >>> + >>> + part->payload[0] = 0x00; /* Start Flag */ >>> + part->payload[1] = 0x01; /* Start Flag */ >>> + >>> + memcpy(&part->payload[2], &ssif_bmc->response.payload[0], >>> part_len); >>> + break; >>> + >>> + case SSIF_IPMI_MULTIPART_READ_MIDDLE: >>> + /* >>> + * IPMI READ Middle or READ End messages can carry up to 31 >>> bytes >>> + * IPMI data plus block number byte. >>> + */ >>> + if (ssif_bmc->remain_len <= >>> MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION) { >>> + /* >>> + * This is READ End message >>> + * Return length is the remaining response data length >>> + * plus block number >>> + * Block number 0xFF is to indicate this is last message >>> + * >>> + */ >>> + /* Clean the buffer */ >>> + memset(&part->payload[0], 0, MAX_PAYLOAD_PER_TRANSACTION); >>> + part->length = ssif_bmc->remain_len + 1; >>> + part_len = ssif_bmc->remain_len; >>> + ssif_bmc->block_num = 0xFF; >>> + part->payload[0] = ssif_bmc->block_num; >>> + } else { >>> + /* >>> + * This is READ Middle message >>> + * Response length is the maximum SMBUS transfer length >>> + * Block number byte is incremented >>> + * Return length is maximum SMBUS transfer length >>> + */ >>> + part->length = MAX_PAYLOAD_PER_TRANSACTION; >>> + part_len = MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION; >>> + part->payload[0] = ssif_bmc->block_num; >>> + ssif_bmc->block_num++; >>> + } >>> + >>> + ssif_bmc->remain_len -= part_len; >>> + memcpy(&part->payload[1], ssif_bmc->response.payload + >>> ssif_bmc->nbytes_processed, >>> + part_len); >>> + break; >>> + >>> + default: >>> + /* Do not expect to go to this case */ >>> + dev_err(&ssif_bmc->client->dev, "%s: Unexpected SMBus >>> command 0x%x\n", >>> + __func__, part->smbus_cmd); >>> + break; >>> + } >>> + >>> + ssif_bmc->nbytes_processed += part_len; >>> +} >>> + >>> +static bool supported_read_cmd(u8 cmd) >>> +{ >>> + if (cmd == SSIF_IPMI_SINGLEPART_READ || >>> + cmd == SSIF_IPMI_MULTIPART_READ_START || >>> + cmd == SSIF_IPMI_MULTIPART_READ_MIDDLE) >>> + return true; >>> + >>> + return false; >>> +} >>> + >>> +static bool supported_write_cmd(u8 cmd) >>> +{ >>> + if (cmd == SSIF_IPMI_SINGLEPART_WRITE || >>> + cmd == SSIF_IPMI_MULTIPART_WRITE_START || >>> + cmd == SSIF_IPMI_MULTIPART_WRITE_MIDDLE || >>> + cmd == SSIF_IPMI_MULTIPART_WRITE_END) >>> + return true; >>> + >>> + return false; >>> +} >>> + >>> +/* Process the IPMI response that will be read by master */ >>> +static void handle_read_processed(struct ssif_bmc_ctx *ssif_bmc, u8 >>> *val) >>> +{ >>> + struct ssif_part_buffer *part = &ssif_bmc->part_buf; >>> + >>> + /* msg_idx start from 0 */ >>> + if (part->index < part->length) >>> + *val = part->payload[part->index]; >>> + else if (part->index == part->length && ssif_bmc->pec_support) >>> + *val = part->pec; >>> + else >>> + *val = 0; >>> + >>> + part->index++; >>> +} >>> + >>> +static void handle_write_received(struct ssif_bmc_ctx *ssif_bmc, u8 >>> *val) >>> +{ >>> + /* >>> + * The msg_idx must be 1 when first enter SSIF_REQ_RECVING state >>> + * And it would never exceeded 36 bytes included the 32 bytes >>> max payload + >>> + * the address + the command + the len and the PEC. >>> + */ >>> + if (ssif_bmc->msg_idx < 1 || ssif_bmc->msg_idx > MAX_TRANSACTION) >>> + return; >>> + >>> + if (ssif_bmc->msg_idx == 1) { >>> + ssif_bmc->part_buf.length = *val; >>> + ssif_bmc->part_buf.index = 0; >>> + } else { >>> + ssif_bmc->part_buf.payload[ssif_bmc->part_buf.index++] = *val; >>> + } >>> + >>> + ssif_bmc->msg_idx++; >>> +} >>> + >>> +static bool validate_request_part(struct ssif_bmc_ctx *ssif_bmc) >>> +{ >>> + struct ssif_part_buffer *part = &ssif_bmc->part_buf; >>> + bool ret = true; >>> + u8 cpec; >>> + u8 addr; >>> + >>> + if (part->index == part->length) { >>> + /* PEC is not included */ >>> + ssif_bmc->pec_support = false; >>> + ret = true; >>> + goto exit; >>> + } >>> + >>> + if (part->index != part->length + 1) { >>> + ret = false; >>> + goto exit; >>> + } >>> + >>> + /* PEC is included */ >>> + ssif_bmc->pec_support = true; >>> + part->pec = part->payload[part->length]; >>> + addr = GET_8BIT_ADDR(ssif_bmc->client->addr); >>> + cpec = i2c_smbus_pec(0, &addr, 1); >>> + cpec = i2c_smbus_pec(cpec, &part->smbus_cmd, 1); >>> + cpec = i2c_smbus_pec(cpec, &part->length, 1); >>> + /* >>> + * As SMBus specification does not allow the length >>> + * (byte count) in the Write-Block protocol to be zero. >>> + * Therefore, it is illegal to have the last Middle >>> + * transaction in the sequence carry 32-byte and have >>> + * a length of ‘0’ in the End transaction. >>> + * But some users may try to use this way and we should >>> + * prevent ssif_bmc driver broken in this case. >>> + */ >>> + if (part->length) >>> + cpec = i2c_smbus_pec(cpec, part->payload, part->length); >>> + >>> + if (cpec != part->pec) >>> + ret = false; >>> + >>> +exit: >>> + return ret; >>> +} >>> + >>> +static void process_request_part(struct ssif_bmc_ctx *ssif_bmc) >>> +{ >>> + struct ssif_part_buffer *part = &ssif_bmc->part_buf; >>> + unsigned int len; >>> + >>> + switch (part->smbus_cmd) { >>> + case SSIF_IPMI_SINGLEPART_WRITE: >>> + /* save the whole part to request*/ >>> + ssif_bmc->request.len = part->length; >>> + memcpy(ssif_bmc->request.payload, part->payload, >>> part->length); >>> + >>> + break; >>> + case SSIF_IPMI_MULTIPART_WRITE_START: >>> + ssif_bmc->request.len = 0; >>> + >>> + fallthrough; >>> + case SSIF_IPMI_MULTIPART_WRITE_MIDDLE: >>> + case SSIF_IPMI_MULTIPART_WRITE_END: >>> + len = ssif_bmc->request.len + part->length; >>> + /* Do the bound check here, not allow the request len >>> exceed 254 bytes */ >>> + if (len > IPMI_SSIF_PAYLOAD_MAX) { >>> + dev_warn(&ssif_bmc->client->dev, >>> + "Warn: Request exceeded 254 bytes, aborting"); >>> + /* Request too long, aborting */ >>> + ssif_bmc->aborting = true; >>> + } else { >>> + memcpy(ssif_bmc->request.payload + ssif_bmc->request.len, >>> + part->payload, part->length); >>> + ssif_bmc->request.len += part->length; >>> + } >>> + break; >>> + default: >>> + /* Do not expect to go to this case */ >>> + dev_err(&ssif_bmc->client->dev, "%s: Unexpected SMBus >>> command 0x%x\n", >>> + __func__, part->smbus_cmd); >>> + break; >>> + } >>> +} >>> + >>> +static void process_smbus_cmd(struct ssif_bmc_ctx *ssif_bmc, u8 *val) >>> +{ >>> + /* SMBUS command can vary (single or multi-part) */ >>> + ssif_bmc->part_buf.smbus_cmd = *val; >>> + ssif_bmc->msg_idx = 1; >>> + memset(&ssif_bmc->part_buf.payload[0], 0, >>> MAX_PAYLOAD_PER_TRANSACTION); >>> + >>> + if (*val == SSIF_IPMI_SINGLEPART_WRITE || *val == >>> SSIF_IPMI_MULTIPART_WRITE_START) { >>> + /* >>> + * The response maybe not come in-time, causing host SSIF >>> driver >>> + * to timeout and resend a new request. In such case check for >>> + * pending response and clear it >>> + */ >>> + if (ssif_bmc->response_in_progress) >>> + complete_response(ssif_bmc); >>> + >>> + /* This is new request, flip aborting flag if set */ >>> + if (ssif_bmc->aborting) >>> + ssif_bmc->aborting = false; >>> + } >>> +} >>> + >>> +static void on_read_requested_event(struct ssif_bmc_ctx *ssif_bmc, >>> u8 *val) >>> +{ >>> + if (ssif_bmc->state == SSIF_READY || >> Is this actually correct? The state machine seems to set this as the >> default state and in my testing we seem to always reach here with the >> state == SSIF_READY? > The I2C_SLAVE_READ_REQUESTED event is expected to come on > SSIF_SMBUS_CMD state where Slave has already received and validated > the SMBus command, in this case is the I2C_SLAVE_READ_REQUESTED event > if the SMBus command indeed is the READ command. You can see the check > supported_read_cmd() below. > > If Slave see the I2C_SLAVE_READ_REQUESTED event on other states, it > will transition to SSIF_ABORTING state that discard everything until > there is a new transaction come. > > On READ, the sequence of Slave event should be as below: > I2C_SLAVE_WRITE_REQUESTED (addr) => I2C_SLAVE_WRITE_RECEIVED (SMBus > cmd) => I2C_SLAVE_READ_REQUESTED (Slave feed the first byte) => > I2C_SLAVE_READ_PROCESSED (Slave 2nd byte) => .... => I2C_SLAVE_STOP > >>> + ssif_bmc->state == SSIF_START || >>> + ssif_bmc->state == SSIF_REQ_RECVING || >>> + ssif_bmc->state == SSIF_RES_SENDING) { >>> + dev_warn(&ssif_bmc->client->dev, >>> + "Warn: %s unexpected READ REQUESTED in state=%s\n", >>> + __func__, state_to_string(ssif_bmc->state)); >>> + ssif_bmc->state = SSIF_ABORTING; >>> + *val = 0; >>> + return; >>> + >>> + } else if (ssif_bmc->state == SSIF_SMBUS_CMD) { >>> + if (!supported_read_cmd(ssif_bmc->part_buf.smbus_cmd)) { >>> + dev_warn(&ssif_bmc->client->dev, "Warn: Unknown SMBus >>> read command=0x%x", >>> + ssif_bmc->part_buf.smbus_cmd); >>> + ssif_bmc->aborting = true; >>> + } >>> + >>> + if (ssif_bmc->aborting) >>> + ssif_bmc->state = SSIF_ABORTING; >>> + else >>> + ssif_bmc->state = SSIF_RES_SENDING; >>> + } >>> + >>> + ssif_bmc->msg_idx = 0; >>> + >>> + /* Send 0 if there is nothing to send */ >>> + if (!ssif_bmc->response_in_progress || ssif_bmc->state == >>> SSIF_ABORTING) { >>> + *val = 0; >>> + return; >>> + } >>> + >>> + if (ssif_bmc->is_singlepart_read) >>> + set_singlepart_response_buffer(ssif_bmc); >>> + else >>> + set_multipart_response_buffer(ssif_bmc); >>> + >>> + calculate_response_part_pec(&ssif_bmc->part_buf); >>> + ssif_bmc->part_buf.index = 0; >>> + *val = ssif_bmc->part_buf.length; >>> +} >>> + >>> +static void on_read_processed_event(struct ssif_bmc_ctx *ssif_bmc, >>> u8 *val) >>> +{ >>> + if (ssif_bmc->state == SSIF_READY || >> Same comment as above? > > Same here, I2C_SLAVE_READ_PROCESSED is expected to come after the > I2C_SLAVE_READ_REQUESTED or other I2C_SLAVE_READ_PROCESSED. ie: when > the state is SSIF_RES_SENDING. > If it comes when Slave in states other than SSIF_RES_SENDING, the > Slave will transition to SSIF_ABORTING state. > >>> + ssif_bmc->state == SSIF_START || >>> + ssif_bmc->state == SSIF_REQ_RECVING || >>> + ssif_bmc->state == SSIF_SMBUS_CMD) { >>> + dev_warn(&ssif_bmc->client->dev, >>> + "Warn: %s unexpected READ PROCESSED in state=%s\n", >>> + __func__, state_to_string(ssif_bmc->state)); >>> + ssif_bmc->state = SSIF_ABORTING; >>> + *val = 0; >>> + return; >>> + } >>> + >>> + /* Send 0 if there is nothing to send */ >>> + if (!ssif_bmc->response_in_progress || ssif_bmc->state == >>> SSIF_ABORTING) { >>> + *val = 0; >>> + return; >>> + } >>> + >>> + handle_read_processed(ssif_bmc, val); >>> +} >>> + >>> +static void on_write_requested_event(struct ssif_bmc_ctx *ssif_bmc, >>> u8 *val) >>> +{ >>> + if (ssif_bmc->state == SSIF_READY || ssif_bmc->state == >>> SSIF_SMBUS_CMD) { >>> + ssif_bmc->state = SSIF_START; >>> + >>> + } else if (ssif_bmc->state == SSIF_START || >>> + ssif_bmc->state == SSIF_REQ_RECVING || >>> + ssif_bmc->state == SSIF_RES_SENDING) { >>> + dev_warn(&ssif_bmc->client->dev, >>> + "Warn: %s unexpected WRITE REQUEST in state=%s\n", >>> + __func__, state_to_string(ssif_bmc->state)); >>> + ssif_bmc->state = SSIF_ABORTING; >>> + return; >>> + } >>> + >>> + ssif_bmc->msg_idx = 0; >>> + ssif_bmc->part_buf.address = *val; >>> +} >>> + >>> +static void on_write_received_event(struct ssif_bmc_ctx *ssif_bmc, >>> u8 *val) >>> +{ >>> + if (ssif_bmc->state == SSIF_READY || >>> + ssif_bmc->state == SSIF_RES_SENDING) { >>> + dev_warn(&ssif_bmc->client->dev, >>> + "Warn: %s unexpected WRITE RECEIVED in state=%s\n", >>> + __func__, state_to_string(ssif_bmc->state)); >>> + ssif_bmc->state = SSIF_ABORTING; >>> + >>> + } else if (ssif_bmc->state == SSIF_START) { >>> + ssif_bmc->state = SSIF_SMBUS_CMD; >>> + >>> + } else if (ssif_bmc->state == SSIF_SMBUS_CMD) { >>> + if (!supported_write_cmd(ssif_bmc->part_buf.smbus_cmd)) { >>> + dev_warn(&ssif_bmc->client->dev, "Warn: Unknown SMBus >>> write command=0x%x", >>> + ssif_bmc->part_buf.smbus_cmd); >>> + ssif_bmc->aborting = true; >>> + } >>> + >>> + if (ssif_bmc->aborting) >>> + ssif_bmc->state = SSIF_ABORTING; >>> + else >>> + ssif_bmc->state = SSIF_REQ_RECVING; >>> + } >>> + >>> + /* This is response sending state */ >>> + if (ssif_bmc->state == SSIF_REQ_RECVING) >>> + handle_write_received(ssif_bmc, val); >>> + else if (ssif_bmc->state == SSIF_SMBUS_CMD) >>> + process_smbus_cmd(ssif_bmc, val); >>> +} >>> + >>> +static void on_stop_event(struct ssif_bmc_ctx *ssif_bmc, u8 *val) >>> +{ >>> + if (ssif_bmc->state == SSIF_READY || >>> + ssif_bmc->state == SSIF_START || >>> + ssif_bmc->state == SSIF_SMBUS_CMD || >>> + ssif_bmc->state == SSIF_ABORTING) { >>> + dev_warn(&ssif_bmc->client->dev, >>> + "Warn: %s unexpected SLAVE STOP in state=%s\n", >>> + __func__, state_to_string(ssif_bmc->state)); >>> + ssif_bmc->state = SSIF_READY; >>> + >>> + } else if (ssif_bmc->state == SSIF_REQ_RECVING) { >>> + if (validate_request_part(ssif_bmc)) { >>> + process_request_part(ssif_bmc); >>> + if (ssif_bmc->part_buf.smbus_cmd == >>> SSIF_IPMI_SINGLEPART_WRITE || >>> + ssif_bmc->part_buf.smbus_cmd == >>> SSIF_IPMI_MULTIPART_WRITE_END) >>> + handle_request(ssif_bmc); >>> + ssif_bmc->state = SSIF_READY; >>> + } else { >>> + /* >>> + * A BMC that receives an invalid request drop the data >>> for the write >>> + * transaction and any further transactions (read or >>> write) until >>> + * the next valid read or write Start transaction is >>> received >>> + */ >>> + dev_err(&ssif_bmc->client->dev, "Error: invalid pec\n"); >>> + ssif_bmc->aborting = true; >>> + } >>> + } else if (ssif_bmc->state == SSIF_RES_SENDING) { >>> + if (ssif_bmc->is_singlepart_read || ssif_bmc->block_num == >>> 0xFF) >>> + /* Invalidate response buffer to denote it is sent */ >>> + complete_response(ssif_bmc); >>> + ssif_bmc->state = SSIF_READY; >>> + } >>> + >>> + /* Reset message index */ >>> + ssif_bmc->msg_idx = 0; >>> +} >>> + >>> +/* >>> + * Callback function to handle I2C slave events >>> + */ >>> +static int ssif_bmc_cb(struct i2c_client *client, enum >>> i2c_slave_event event, u8 *val) >>> +{ >>> + unsigned long flags; >>> + struct ssif_bmc_ctx *ssif_bmc = i2c_get_clientdata(client); >>> + int ret = 0; >>> + >>> + spin_lock_irqsave(&ssif_bmc->lock, flags); >>> + >>> + switch (event) { >>> + case I2C_SLAVE_READ_REQUESTED: >>> + on_read_requested_event(ssif_bmc, val); >>> + break; >>> + >>> + case : >>> + on_write_requested_event(ssif_bmc, val); >>> + break; >>> + >>> + case I2C_SLAVE_READ_PROCESSED: >>> + on_read_processed_event(ssif_bmc, val); >>> + break; >>> + >>> + case I2C_SLAVE_WRITE_RECEIVED: >>> + on_write_received_event(ssif_bmc, val); >>> + break; >>> + >>> + case I2C_SLAVE_STOP: >>> + on_stop_event(ssif_bmc, val); >>> + break; >>> + >>> + default: >>> + dev_warn(&ssif_bmc->client->dev, "Warn: Unknown i2c slave >>> event\n"); >>> + break; >>> + } >>> + >>> + if (!ssif_bmc->aborting && ssif_bmc->busy) >>> + ret = -EBUSY; >>> + >>> + spin_unlock_irqrestore(&ssif_bmc->lock, flags); >>> + >>> + return ret; >>> +} >>> + >>> +static int ssif_bmc_probe(struct i2c_client *client, const struct >>> i2c_device_id *id) >>> +{ >>> + struct ssif_bmc_ctx *ssif_bmc; >>> + int ret; >>> + >>> + ssif_bmc = devm_kzalloc(&client->dev, sizeof(*ssif_bmc), >>> GFP_KERNEL); >>> + if (!ssif_bmc) >>> + return -ENOMEM; >>> + >>> + spin_lock_init(&ssif_bmc->lock); >>> + >>> + init_waitqueue_head(&ssif_bmc->wait_queue); >>> + ssif_bmc->request_available = false; >>> + ssif_bmc->response_in_progress = false; >>> + ssif_bmc->busy = false; >>> + ssif_bmc->response_timer_inited = false; >>> + >>> + /* Register misc device interface */ >>> + ssif_bmc->miscdev.minor = MISC_DYNAMIC_MINOR; >>> + ssif_bmc->miscdev.name = DEVICE_NAME; >>> + ssif_bmc->miscdev.fops = &ssif_bmc_fops; >>> + ssif_bmc->miscdev.parent = &client->dev; >>> + ret = misc_register(&ssif_bmc->miscdev); >>> + if (ret) >>> + return ret; >>> + >>> + ssif_bmc->client = client; >>> + ssif_bmc->client->flags |= I2C_CLIENT_SLAVE; >>> + >>> + /* Register I2C slave */ >>> + i2c_set_clientdata(client, ssif_bmc); >>> + ret = i2c_slave_register(client, ssif_bmc_cb); >>> + if (ret) >>> + misc_deregister(&ssif_bmc->miscdev); >>> + >>> + return ret; >>> +} >>> + >>> +static void ssif_bmc_remove(struct i2c_client *client) >>> +{ >>> + struct ssif_bmc_ctx *ssif_bmc = i2c_get_clientdata(client); >>> + >>> + i2c_slave_unregister(client); >>> + misc_deregister(&ssif_bmc->miscdev); >>> +} >>> + >>> +static const struct of_device_id ssif_bmc_match[] = { >>> + { .compatible = "ssif-bmc" }, >>> + { }, >>> +}; >>> +MODULE_DEVICE_TABLE(of, ssif_bmc_match); >>> + >>> +static const struct i2c_device_id ssif_bmc_id[] = { >>> + { DEVICE_NAME, 0 }, >>> + { }, >>> +}; >>> +MODULE_DEVICE_TABLE(i2c, ssif_bmc_id); >>> + >>> +static struct i2c_driver ssif_bmc_driver = { >>> + .driver = { >>> + .name = DEVICE_NAME, >>> + .of_match_table = ssif_bmc_match, >>> + }, >>> + .probe = ssif_bmc_probe, >>> + .remove = ssif_bmc_remove, >>> + .id_table = ssif_bmc_id, >>> +}; >>> + >>> +module_i2c_driver(ssif_bmc_driver); >>> + >>> +MODULE_AUTHOR("Quan Nguyen <quan@os.amperecomputing.com>"); >>> +MODULE_AUTHOR("Chuong Tran <chuong@os.amperecomputing.com>"); >>> +MODULE_DESCRIPTION("Linux device driver of the BMC IPMI SSIF >>> interface."); >>> +MODULE_LICENSE("GPL"); >>> diff --git a/include/uapi/linux/ipmi_ssif_bmc.h >>> b/include/uapi/linux/ipmi_ssif_bmc.h >>> new file mode 100644 >>> index 000000000000..1c6a753dad08 >>> --- /dev/null >>> +++ b/include/uapi/linux/ipmi_ssif_bmc.h >>> @@ -0,0 +1,18 @@ >>> +/* SPDX-License-Identifier: GPL-2.0-only WITH Linux-syscall-note*/ >>> +/* >>> + * Copyright (c) 2022, Ampere Computing LLC. >>> + */ >>> + >>> +#ifndef _UAPI_LINUX_IPMI_SSIF_BMC_H >>> +#define _UAPI_LINUX_IPMI_SSIF_BMC_H >>> + >>> +#include <linux/types.h> >>> + >>> +/* Max length of ipmi ssif message included netfn and cmd field */ >>> +#define IPMI_SSIF_PAYLOAD_MAX 254 >>> +struct ipmi_ssif_msg { >>> + unsigned int len; >>> + __u8 payload[IPMI_SSIF_PAYLOAD_MAX]; >>> +}; >>> + >>> +#endif /* _UAPI_LINUX_IPMI_SSIF_BMC_H */
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