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ipmi: ssif_bmc: Add SSIF BMC driver
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> Message-Id: <20221004093106.1653317-2-quan@os.amperecomputing.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
This commit is contained in:
Quan Nguyen
Corey Minyard
parent
9abf2313ad
commit
dd2bc5cc9e
@ -169,6 +169,16 @@ config ASPEED_BT_IPMI_BMC
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found on Aspeed SOCs (AST2400 and AST2500). The driver
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implements the BMC side of the BT interface.
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config SSIF_IPMI_BMC
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tristate "SSIF IPMI BMC driver"
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depends on I2C && I2C_SLAVE
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help
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This enables the IPMI SMBus system interface (SSIF) at the
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management (BMC) side.
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The driver implements the BMC side of the SMBus system
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interface (SSIF).
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config IPMB_DEVICE_INTERFACE
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tristate 'IPMB Interface handler'
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depends on I2C
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@ -30,3 +30,4 @@ obj-$(CONFIG_ASPEED_BT_IPMI_BMC) += bt-bmc.o
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obj-$(CONFIG_ASPEED_KCS_IPMI_BMC) += kcs_bmc_aspeed.o
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obj-$(CONFIG_NPCM7XX_KCS_IPMI_BMC) += kcs_bmc_npcm7xx.o
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obj-$(CONFIG_IPMB_DEVICE_INTERFACE) += ipmb_dev_int.o
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obj-$(CONFIG_SSIF_IPMI_BMC) += ssif_bmc.o
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873
drivers/char/ipmi/ssif_bmc.c
Normal file
873
drivers/char/ipmi/ssif_bmc.c
Normal file
@ -0,0 +1,873 @@
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// SPDX-License-Identifier: GPL-2.0-only
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/*
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* The driver for BMC side of SSIF interface
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*
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* Copyright (c) 2022, Ampere Computing LLC
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*
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*/
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#include <linux/i2c.h>
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#include <linux/miscdevice.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/poll.h>
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#include <linux/sched.h>
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#include <linux/mutex.h>
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#include <linux/spinlock.h>
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#include <linux/timer.h>
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#include <linux/jiffies.h>
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#include <linux/ipmi_ssif_bmc.h>
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#define DEVICE_NAME "ipmi-ssif-host"
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#define GET_8BIT_ADDR(addr_7bit) (((addr_7bit) << 1) & 0xff)
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/* A standard SMBus Transaction is limited to 32 data bytes */
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#define MAX_PAYLOAD_PER_TRANSACTION 32
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/* Transaction includes the address, the command, the length and the PEC byte */
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#define MAX_TRANSACTION (MAX_PAYLOAD_PER_TRANSACTION + 4)
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#define MAX_IPMI_DATA_PER_START_TRANSACTION 30
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#define MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION 31
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#define SSIF_IPMI_SINGLEPART_WRITE 0x2
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#define SSIF_IPMI_SINGLEPART_READ 0x3
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#define SSIF_IPMI_MULTIPART_WRITE_START 0x6
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#define SSIF_IPMI_MULTIPART_WRITE_MIDDLE 0x7
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#define SSIF_IPMI_MULTIPART_WRITE_END 0x8
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#define SSIF_IPMI_MULTIPART_READ_START 0x3
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#define SSIF_IPMI_MULTIPART_READ_MIDDLE 0x9
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/*
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* IPMI 2.0 Spec, section 12.7 SSIF Timing,
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* Request-to-Response Time is T6max(250ms) - T1max(20ms) - 3ms = 227ms
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* Recover ssif_bmc from busy state if it takes up to 500ms
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*/
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#define RESPONSE_TIMEOUT 500 /* ms */
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struct ssif_part_buffer {
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u8 address;
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u8 smbus_cmd;
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u8 length;
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u8 payload[MAX_PAYLOAD_PER_TRANSACTION];
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u8 pec;
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u8 index;
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};
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/*
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* SSIF internal states:
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* SSIF_READY 0x00 : Ready state
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* SSIF_START 0x01 : Start smbus transaction
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* SSIF_SMBUS_CMD 0x02 : Received SMBus command
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* SSIF_REQ_RECVING 0x03 : Receiving request
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* SSIF_RES_SENDING 0x04 : Sending response
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* SSIF_ABORTING 0x05 : Aborting state
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*/
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enum ssif_state {
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SSIF_READY,
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SSIF_START,
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SSIF_SMBUS_CMD,
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SSIF_REQ_RECVING,
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SSIF_RES_SENDING,
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SSIF_ABORTING,
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SSIF_STATE_MAX
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};
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struct ssif_bmc_ctx {
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struct i2c_client *client;
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struct miscdevice miscdev;
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int msg_idx;
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bool pec_support;
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/* ssif bmc spinlock */
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spinlock_t lock;
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wait_queue_head_t wait_queue;
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u8 running;
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enum ssif_state state;
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/* Timeout waiting for response */
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struct timer_list response_timer;
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bool response_timer_inited;
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/* Flag to identify a Multi-part Read Transaction */
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bool is_singlepart_read;
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u8 nbytes_processed;
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u8 remain_len;
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u8 recv_len;
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/* Block Number of a Multi-part Read Transaction */
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u8 block_num;
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bool request_available;
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bool response_in_progress;
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bool busy;
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bool aborting;
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/* Buffer for SSIF Transaction part*/
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struct ssif_part_buffer part_buf;
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struct ipmi_ssif_msg response;
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struct ipmi_ssif_msg request;
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};
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static inline struct ssif_bmc_ctx *to_ssif_bmc(struct file *file)
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{
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return container_of(file->private_data, struct ssif_bmc_ctx, miscdev);
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}
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static const char *state_to_string(enum ssif_state state)
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{
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switch (state) {
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case SSIF_READY:
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return "SSIF_READY";
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case SSIF_START:
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return "SSIF_START";
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case SSIF_SMBUS_CMD:
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return "SSIF_SMBUS_CMD";
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case SSIF_REQ_RECVING:
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return "SSIF_REQ_RECVING";
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case SSIF_RES_SENDING:
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return "SSIF_RES_SENDING";
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case SSIF_ABORTING:
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return "SSIF_ABORTING";
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default:
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return "SSIF_STATE_UNKNOWN";
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}
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}
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/* Handle SSIF message that will be sent to user */
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static ssize_t ssif_bmc_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
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{
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struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file);
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struct ipmi_ssif_msg msg;
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unsigned long flags;
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ssize_t ret;
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spin_lock_irqsave(&ssif_bmc->lock, flags);
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while (!ssif_bmc->request_available) {
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spin_unlock_irqrestore(&ssif_bmc->lock, flags);
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if (file->f_flags & O_NONBLOCK)
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return -EAGAIN;
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ret = wait_event_interruptible(ssif_bmc->wait_queue,
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ssif_bmc->request_available);
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if (ret)
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return ret;
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spin_lock_irqsave(&ssif_bmc->lock, flags);
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}
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if (count < min_t(ssize_t,
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sizeof_field(struct ipmi_ssif_msg, len) + ssif_bmc->request.len,
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sizeof(struct ipmi_ssif_msg))) {
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spin_unlock_irqrestore(&ssif_bmc->lock, flags);
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ret = -EINVAL;
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} else {
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count = min_t(ssize_t,
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sizeof_field(struct ipmi_ssif_msg, len) + ssif_bmc->request.len,
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sizeof(struct ipmi_ssif_msg));
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memcpy(&msg, &ssif_bmc->request, count);
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ssif_bmc->request_available = false;
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spin_unlock_irqrestore(&ssif_bmc->lock, flags);
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ret = copy_to_user(buf, &msg, count);
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}
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return (ret < 0) ? ret : count;
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}
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/* Handle SSIF message that is written by user */
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static ssize_t ssif_bmc_write(struct file *file, const char __user *buf, size_t count,
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loff_t *ppos)
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{
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struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file);
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struct ipmi_ssif_msg msg;
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unsigned long flags;
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ssize_t ret;
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if (count > sizeof(struct ipmi_ssif_msg))
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return -EINVAL;
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if (copy_from_user(&msg, buf, count))
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return -EFAULT;
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if (!msg.len || count < sizeof_field(struct ipmi_ssif_msg, len) + msg.len)
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return -EINVAL;
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spin_lock_irqsave(&ssif_bmc->lock, flags);
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while (ssif_bmc->response_in_progress) {
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spin_unlock_irqrestore(&ssif_bmc->lock, flags);
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if (file->f_flags & O_NONBLOCK)
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return -EAGAIN;
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ret = wait_event_interruptible(ssif_bmc->wait_queue,
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!ssif_bmc->response_in_progress);
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if (ret)
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return ret;
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spin_lock_irqsave(&ssif_bmc->lock, flags);
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}
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/*
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* The write must complete before the response timeout fired, otherwise
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* the response is aborted and wait for next request
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* Return -EINVAL if the response is aborted
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*/
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ret = (ssif_bmc->response_timer_inited) ? 0 : -EINVAL;
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if (ret)
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goto exit;
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del_timer(&ssif_bmc->response_timer);
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ssif_bmc->response_timer_inited = false;
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memcpy(&ssif_bmc->response, &msg, count);
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ssif_bmc->is_singlepart_read = (msg.len <= MAX_PAYLOAD_PER_TRANSACTION);
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ssif_bmc->response_in_progress = true;
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/* ssif_bmc not busy */
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ssif_bmc->busy = false;
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/* Clean old request buffer */
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memset(&ssif_bmc->request, 0, sizeof(struct ipmi_ssif_msg));
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exit:
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spin_unlock_irqrestore(&ssif_bmc->lock, flags);
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return (ret < 0) ? ret : count;
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}
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static int ssif_bmc_open(struct inode *inode, struct file *file)
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{
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struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file);
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int ret = 0;
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spin_lock_irq(&ssif_bmc->lock);
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if (!ssif_bmc->running)
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ssif_bmc->running = 1;
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else
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ret = -EBUSY;
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spin_unlock_irq(&ssif_bmc->lock);
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return ret;
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}
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static __poll_t ssif_bmc_poll(struct file *file, poll_table *wait)
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{
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struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file);
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__poll_t mask = 0;
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poll_wait(file, &ssif_bmc->wait_queue, wait);
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spin_lock_irq(&ssif_bmc->lock);
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/* The request is available, userspace application can get the request */
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if (ssif_bmc->request_available)
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mask |= POLLIN;
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spin_unlock_irq(&ssif_bmc->lock);
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return mask;
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}
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static int ssif_bmc_release(struct inode *inode, struct file *file)
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{
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struct ssif_bmc_ctx *ssif_bmc = to_ssif_bmc(file);
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spin_lock_irq(&ssif_bmc->lock);
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ssif_bmc->running = 0;
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spin_unlock_irq(&ssif_bmc->lock);
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return 0;
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}
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/*
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* System calls to device interface for user apps
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*/
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static const struct file_operations ssif_bmc_fops = {
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.owner = THIS_MODULE,
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.open = ssif_bmc_open,
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.read = ssif_bmc_read,
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.write = ssif_bmc_write,
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.release = ssif_bmc_release,
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.poll = ssif_bmc_poll,
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};
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/* Called with ssif_bmc->lock held. */
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static void complete_response(struct ssif_bmc_ctx *ssif_bmc)
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{
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/* Invalidate response in buffer to denote it having been sent. */
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ssif_bmc->response.len = 0;
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ssif_bmc->response_in_progress = false;
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ssif_bmc->nbytes_processed = 0;
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ssif_bmc->remain_len = 0;
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ssif_bmc->busy = false;
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memset(&ssif_bmc->part_buf, 0, sizeof(struct ssif_part_buffer));
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wake_up_all(&ssif_bmc->wait_queue);
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}
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static void response_timeout(struct timer_list *t)
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{
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struct ssif_bmc_ctx *ssif_bmc = from_timer(ssif_bmc, t, response_timer);
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unsigned long flags;
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spin_lock_irqsave(&ssif_bmc->lock, flags);
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/* Do nothing if the response is in progress */
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if (!ssif_bmc->response_in_progress) {
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/* Recover ssif_bmc from busy */
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ssif_bmc->busy = false;
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ssif_bmc->response_timer_inited = false;
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/* Set aborting flag */
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ssif_bmc->aborting = true;
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}
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spin_unlock_irqrestore(&ssif_bmc->lock, flags);
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}
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/* Called with ssif_bmc->lock held. */
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static void handle_request(struct ssif_bmc_ctx *ssif_bmc)
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{
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/* set ssif_bmc to busy waiting for response */
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ssif_bmc->busy = true;
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/* Request message is available to process */
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ssif_bmc->request_available = true;
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/* Clean old response buffer */
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memset(&ssif_bmc->response, 0, sizeof(struct ipmi_ssif_msg));
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/* This is the new READ request.*/
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wake_up_all(&ssif_bmc->wait_queue);
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/* Armed timer to recover slave from busy state in case of no response */
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if (!ssif_bmc->response_timer_inited) {
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timer_setup(&ssif_bmc->response_timer, response_timeout, 0);
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ssif_bmc->response_timer_inited = true;
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}
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mod_timer(&ssif_bmc->response_timer, jiffies + msecs_to_jiffies(RESPONSE_TIMEOUT));
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}
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static void calculate_response_part_pec(struct ssif_part_buffer *part)
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{
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u8 addr = part->address;
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/* PEC - Start Read Address */
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part->pec = i2c_smbus_pec(0, &addr, 1);
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/* PEC - SSIF Command */
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part->pec = i2c_smbus_pec(part->pec, &part->smbus_cmd, 1);
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/* PEC - Restart Write Address */
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addr = addr | 0x01;
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part->pec = i2c_smbus_pec(part->pec, &addr, 1);
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part->pec = i2c_smbus_pec(part->pec, &part->length, 1);
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if (part->length)
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part->pec = i2c_smbus_pec(part->pec, part->payload, part->length);
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}
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static void set_singlepart_response_buffer(struct ssif_bmc_ctx *ssif_bmc)
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{
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struct ssif_part_buffer *part = &ssif_bmc->part_buf;
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part->address = GET_8BIT_ADDR(ssif_bmc->client->addr);
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part->length = (u8)ssif_bmc->response.len;
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/* Clear the rest to 0 */
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memset(part->payload + part->length, 0, MAX_PAYLOAD_PER_TRANSACTION - part->length);
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memcpy(&part->payload[0], &ssif_bmc->response.payload[0], part->length);
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}
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static void set_multipart_response_buffer(struct ssif_bmc_ctx *ssif_bmc)
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{
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struct ssif_part_buffer *part = &ssif_bmc->part_buf;
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u8 part_len = 0;
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part->address = GET_8BIT_ADDR(ssif_bmc->client->addr);
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switch (part->smbus_cmd) {
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case SSIF_IPMI_MULTIPART_READ_START:
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/*
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* Read Start length is 32 bytes.
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* Read Start transfer first 30 bytes of IPMI response
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* and 2 special code 0x00, 0x01.
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*/
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ssif_bmc->nbytes_processed = 0;
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ssif_bmc->block_num = 0;
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part->length = MAX_PAYLOAD_PER_TRANSACTION;
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part_len = MAX_IPMI_DATA_PER_START_TRANSACTION;
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ssif_bmc->remain_len = ssif_bmc->response.len - part_len;
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part->payload[0] = 0x00; /* Start Flag */
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part->payload[1] = 0x01; /* Start Flag */
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memcpy(&part->payload[2], &ssif_bmc->response.payload[0], part_len);
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break;
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case SSIF_IPMI_MULTIPART_READ_MIDDLE:
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/*
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* IPMI READ Middle or READ End messages can carry up to 31 bytes
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* IPMI data plus block number byte.
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*/
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if (ssif_bmc->remain_len <= MAX_IPMI_DATA_PER_MIDDLE_TRANSACTION) {
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/*
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* This is READ End message
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* Return length is the remaining response data length
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* plus block number
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* Block number 0xFF is to indicate this is last message
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*
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*/
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/* Clean the buffer */
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memset(&part->payload[0], 0, MAX_PAYLOAD_PER_TRANSACTION);
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part->length = ssif_bmc->remain_len + 1;
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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 ||
|
||||
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 ||
|
||||
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 I2C_SLAVE_WRITE_REQUESTED:
|
||||
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");
|
||||
18
include/uapi/linux/ipmi_ssif_bmc.h
Normal file
18
include/uapi/linux/ipmi_ssif_bmc.h
Normal file
@ -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 */
|
||||
Loading…
Reference in New Issue
Block a user