Merge tag 'for-linus-6.2-1' of https://github.com/cminyard/linux-ipmi

Pull IPMI updates from Corey Minyard:
 "This includes a number of small fixes, as usual.

  It also includes a new driver for doing the i2c (SSIF) interface
  BMC-side, pretty much completing the BMC side interfaces"

* tag 'for-linus-6.2-1' of https://github.com/cminyard/linux-ipmi:
  ipmi/watchdog: use strscpy() to instead of strncpy()
  ipmi: ssif_bmc: Convert to i2c's .probe_new()
  ipmi: fix use after free in _ipmi_destroy_user()
  ipmi/watchdog: Include <linux/kstrtox.h> when appropriate
  ipmi:ssif: Increase the message retry time
  ipmi: Fix some kernel-doc warnings
  ipmi: ssif_bmc: Use EPOLLIN instead of POLLIN
  ipmi: fix msg stack when IPMI is disconnected
  ipmi: fix memleak when unload ipmi driver
  ipmi: fix long wait in unload when IPMI disconnect
  ipmi: kcs: Poll OBF briefly to reduce OBE latency
  bindings: ipmi: Add binding for SSIF BMC driver
  ipmi: ssif_bmc: Add SSIF BMC driver

Documentation/devicetree/bindings/ipmi/ssif-bmc.yaml

+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/ipmi/ssif-bmc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SSIF IPMI BMC interface
+
+description: SSIF IPMI BMC device bindings
+
+maintainers:
+  - Quan Nguyen <quan@os.amperecomputing.com>
+
+properties:
+  compatible:
+    enum:
+      - ssif-bmc
+
+  reg:
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        ssif-bmc@10 {
+            compatible = "ssif-bmc";
+            reg = <0x10>;
+        };
+    };

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

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

drivers/char/ipmi/ipmi_kcs_sm.c

@@ -122,10 +122,10 @@ struct si_sm_data {
 	unsigned long  error0_timeout;
 };
 
-static unsigned int init_kcs_data(struct si_sm_data *kcs,
-				  struct si_sm_io *io)
+static unsigned int init_kcs_data_with_state(struct si_sm_data *kcs,
+				  struct si_sm_io *io, enum kcs_states state)
 {
-	kcs->state = KCS_IDLE;
+	kcs->state = state;
 	kcs->io = io;
 	kcs->write_pos = 0;
 	kcs->write_count = 0;
@@ -140,6 +140,12 @@ static unsigned int init_kcs_data(struct si_sm_data *kcs,
 	return 2;
 }
 
+static unsigned int init_kcs_data(struct si_sm_data *kcs,
+				  struct si_sm_io *io)
+{
+	return init_kcs_data_with_state(kcs, io, KCS_IDLE);
+}
+
 static inline unsigned char read_status(struct si_sm_data *kcs)
 {
 	return kcs->io->inputb(kcs->io, 1);
@@ -270,7 +276,7 @@ static int start_kcs_transaction(struct si_sm_data *kcs, unsigned char *data,
 	if (size > MAX_KCS_WRITE_SIZE)
 		return IPMI_REQ_LEN_EXCEEDED_ERR;
 
-	if ((kcs->state != KCS_IDLE) && (kcs->state != KCS_HOSED)) {
+	if (kcs->state != KCS_IDLE) {
 		dev_warn(kcs->io->dev, "KCS in invalid state %d\n", kcs->state);
 		return IPMI_NOT_IN_MY_STATE_ERR;
 	}
@@ -495,7 +501,7 @@ static enum si_sm_result kcs_event(struct si_sm_data *kcs, long time)
 	}
 
 	if (kcs->state == KCS_HOSED) {
-		init_kcs_data(kcs, kcs->io);
+		init_kcs_data_with_state(kcs, kcs->io, KCS_ERROR0);
 		return SI_SM_HOSED;
 	}
 

drivers/char/ipmi/ipmi_msghandler.c

@@ -614,7 +614,7 @@ static int __ipmi_bmc_register(struct ipmi_smi *intf,
 static int __scan_channels(struct ipmi_smi *intf, struct ipmi_device_id *id);
 
 
-/**
+/*
  * The driver model view of the IPMI messaging driver.
  */
 static struct platform_driver ipmidriver = {
@@ -1330,6 +1330,7 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
 	unsigned long    flags;
 	struct cmd_rcvr  *rcvr;
 	struct cmd_rcvr  *rcvrs = NULL;
+	struct module    *owner;
 
 	if (!acquire_ipmi_user(user, &i)) {
 		/*
@@ -1392,8 +1393,9 @@ static void _ipmi_destroy_user(struct ipmi_user *user)
 		kfree(rcvr);
 	}
 
+	owner = intf->owner;
 	kref_put(&intf->refcount, intf_free);
-	module_put(intf->owner);
+	module_put(owner);
 }
 
 int ipmi_destroy_user(struct ipmi_user *user)
@@ -3704,12 +3706,16 @@ static void deliver_smi_err_response(struct ipmi_smi *intf,
 				     struct ipmi_smi_msg *msg,
 				     unsigned char err)
 {
+	int rv;
 	msg->rsp[0] = msg->data[0] | 4;
 	msg->rsp[1] = msg->data[1];
 	msg->rsp[2] = err;
 	msg->rsp_size = 3;
-	/* It's an error, so it will never requeue, no need to check return. */
-	handle_one_recv_msg(intf, msg);
+
+	/* This will never requeue, but it may ask us to free the message. */
+	rv = handle_one_recv_msg(intf, msg);
+	if (rv == 0)
+		ipmi_free_smi_msg(msg);
 }
 
 static void cleanup_smi_msgs(struct ipmi_smi *intf)

drivers/char/ipmi/ipmi_si_intf.c

@@ -2153,6 +2153,20 @@ static int __init init_ipmi_si(void)
 }
 module_init(init_ipmi_si);
 
+static void wait_msg_processed(struct smi_info *smi_info)
+{
+	unsigned long jiffies_now;
+	long time_diff;
+
+	while (smi_info->curr_msg || (smi_info->si_state != SI_NORMAL)) {
+		jiffies_now = jiffies;
+		time_diff = (((long)jiffies_now - (long)smi_info->last_timeout_jiffies)
+		     * SI_USEC_PER_JIFFY);
+		smi_event_handler(smi_info, time_diff);
+		schedule_timeout_uninterruptible(1);
+	}
+}
+
 static void shutdown_smi(void *send_info)
 {
 	struct smi_info *smi_info = send_info;
@@ -2187,16 +2201,13 @@ static void shutdown_smi(void *send_info)
 	 * in the BMC.  Note that timers and CPU interrupts are off,
 	 * so no need for locks.
 	 */
-	while (smi_info->curr_msg || (smi_info->si_state != SI_NORMAL)) {
-		poll(smi_info);
-		schedule_timeout_uninterruptible(1);
-	}
+	wait_msg_processed(smi_info);
+
 	if (smi_info->handlers)
 		disable_si_irq(smi_info);
-	while (smi_info->curr_msg || (smi_info->si_state != SI_NORMAL)) {
-		poll(smi_info);
-		schedule_timeout_uninterruptible(1);
-	}
+
+	wait_msg_processed(smi_info);
+
 	if (smi_info->handlers)
 		smi_info->handlers->cleanup(smi_info->si_sm);
 

drivers/char/ipmi/ipmi_ssif.c

@@ -74,7 +74,7 @@
 /*
  * Timer values
  */
-#define SSIF_MSG_USEC		20000	/* 20ms between message tries. */
+#define SSIF_MSG_USEC		60000	/* 60ms between message tries. */
 #define SSIF_MSG_PART_USEC	5000	/* 5ms for a message part */
 
 /* How many times to we retry sending/receiving the message. */

drivers/char/ipmi/ipmi_watchdog.c

@@ -23,6 +23,7 @@
 #include <linux/init.h>
 #include <linux/completion.h>
 #include <linux/kdebug.h>
+#include <linux/kstrtox.h>
 #include <linux/rwsem.h>
 #include <linux/errno.h>
 #include <linux/uaccess.h>
@@ -212,8 +213,7 @@ static int set_param_str(const char *val, const struct kernel_param *kp)
 	char       valcp[16];
 	char       *s;
 
-	strncpy(valcp, val, 15);
-	valcp[15] = '\0';
+	strscpy(valcp, val, 16);
 
 	s = strstrip(valcp);
 

drivers/char/ipmi/kcs_bmc_aspeed.c

@@ -406,13 +406,31 @@ static void aspeed_kcs_check_obe(struct timer_list *timer)
 static void aspeed_kcs_irq_mask_update(struct kcs_bmc_device *kcs_bmc, u8 mask, u8 state)
 {
 	struct aspeed_kcs_bmc *priv = to_aspeed_kcs_bmc(kcs_bmc);
+	int rc;
+	u8 str;
 
 	/* We don't have an OBE IRQ, emulate it */
 	if (mask & KCS_BMC_EVENT_TYPE_OBE) {
-		if (KCS_BMC_EVENT_TYPE_OBE & state)
-			mod_timer(&priv->obe.timer, jiffies + OBE_POLL_PERIOD);
-		else
+		if (KCS_BMC_EVENT_TYPE_OBE & state) {
+			/*
+			 * Given we don't have an OBE IRQ, delay by polling briefly to see if we can
+			 * observe such an event before returning to the caller. This is not
+			 * incorrect because OBF may have already become clear before enabling the
+			 * IRQ if we had one, under which circumstance no event will be propagated
+			 * anyway.
+			 *
+			 * The onus is on the client to perform a race-free check that it hasn't
+			 * missed the event.
+			 */
+			rc = read_poll_timeout_atomic(aspeed_kcs_inb, str,
+						      !(str & KCS_BMC_STR_OBF), 1, 100, false,
+						      &priv->kcs_bmc, priv->kcs_bmc.ioreg.str);
+			/* Time for the slow path? */
+			if (rc == -ETIMEDOUT)
+				mod_timer(&priv->obe.timer, jiffies + OBE_POLL_PERIOD);
+		} else {
 			del_timer(&priv->obe.timer);
+		}
 	}
 
 	if (mask & KCS_BMC_EVENT_TYPE_IBF) {

include/uapi/linux/ipmi_ssif_bmc.h

+/* 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 */