scsi: ufs: core: Make fault injection dynamically configurable per HBA

The UFS driver has two driver-specific fault injection mechanisms
(trigger_eh and timeout). Each fault injection configuration can only be
specified by a module parameter and cannot be reconfigured without
reloading the driver. Also, each configuration is common to all HBAs.

This change adds the following subdirectories for each UFS HBA when
debugfs is enabled:

  /sys/kernel/debug/ufshcd/<HBA>/timeout_inject
  /sys/kernel/debug/ufshcd/<HBA>/trigger_eh_inject

Each fault injection attribute can be dynamically set per HBA by a
corresponding file in these directories.

This is tested with QEMU UFS devices.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Link: https://lore.kernel.org/r/20231118124443.1007116-1-akinobu.mita@gmail.com
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

3 files changed, 27 insertions, 10 deletions

diff --git a/drivers/ufs/core/ufs-fault-injection.c b/drivers/ufs/core/ufs-fault-injection.c
index 5b1184aac585..169540417079 100644
--- a/drivers/ufs/core/ufs-fault-injection.c
+++ b/drivers/ufs/core/ufs-fault-injection.c
@@ -4,6 +4,7 @@
 #include <linux/types.h>
 #include <linux/fault-inject.h>
 #include <linux/module.h>
+#include <ufs/ufshcd.h>
 #include "ufs-fault-injection.h"
 
 static int ufs_fault_get(char *buffer, const struct kernel_param *kp);
@@ -59,12 +60,22 @@ static int ufs_fault_set(const char *val, const struct kernel_param *kp)
 	return 0;
 }
 
-bool ufs_trigger_eh(void)
+void ufs_fault_inject_hba_init(struct ufs_hba *hba)
 {
-	return should_fail(&ufs_trigger_eh_attr, 1);
+	hba->trigger_eh_attr = ufs_trigger_eh_attr;
+	hba->timeout_attr = ufs_timeout_attr;
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+	fault_create_debugfs_attr("trigger_eh_inject", hba->debugfs_root, &hba->trigger_eh_attr);
+	fault_create_debugfs_attr("timeout_inject", hba->debugfs_root, &hba->timeout_attr);
+#endif
 }
 
-bool ufs_fail_completion(void)
+bool ufs_trigger_eh(struct ufs_hba *hba)
 {
-	return should_fail(&ufs_timeout_attr, 1);
+	return should_fail(&hba->trigger_eh_attr, 1);
+}
+
+bool ufs_fail_completion(struct ufs_hba *hba)
+{
+	return should_fail(&hba->timeout_attr, 1);
 }
diff --git a/drivers/ufs/core/ufs-fault-injection.h b/drivers/ufs/core/ufs-fault-injection.h
index 6d0cd8e10c87..996a35769781 100644
--- a/drivers/ufs/core/ufs-fault-injection.h
+++ b/drivers/ufs/core/ufs-fault-injection.h
@@ -7,15 +7,20 @@
 #include <linux/types.h>
 
 #ifdef CONFIG_SCSI_UFS_FAULT_INJECTION
-bool ufs_trigger_eh(void);
-bool ufs_fail_completion(void);
+void ufs_fault_inject_hba_init(struct ufs_hba *hba);
+bool ufs_trigger_eh(struct ufs_hba *hba);
+bool ufs_fail_completion(struct ufs_hba *hba);
 #else
-static inline bool ufs_trigger_eh(void)
+static inline void ufs_fault_inject_hba_init(struct ufs_hba *hba)
+{
+}
+
+static inline bool ufs_trigger_eh(struct ufs_hba *hba)
 {
 	return false;
 }
 
-static inline bool ufs_fail_completion(void)
+static inline bool ufs_fail_completion(struct ufs_hba *hba)
 {
 	return false;
 }
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 8b1031fb0a44..63f0ee117399 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -2992,7 +2992,7 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 	ufshcd_send_command(hba, tag, hwq);
 
 out:
-	if (ufs_trigger_eh()) {
+	if (ufs_trigger_eh(hba)) {
 		unsigned long flags;
 
 		spin_lock_irqsave(hba->host->host_lock, flags);
@@ -5649,7 +5649,7 @@ static irqreturn_t ufshcd_transfer_req_compl(struct ufs_hba *hba)
 	    !(hba->quirks & UFSHCI_QUIRK_SKIP_RESET_INTR_AGGR))
 		ufshcd_reset_intr_aggr(hba);
 
-	if (ufs_fail_completion())
+	if (ufs_fail_completion(hba))
 		return IRQ_HANDLED;
 
 	/*
@@ -9348,6 +9348,7 @@ static int ufshcd_hba_init(struct ufs_hba *hba)
 		goto out_disable_vreg;
 
 	ufs_debugfs_hba_init(hba);
+	ufs_fault_inject_hba_init(hba);
 
 	hba->is_powered = true;
 	goto out;