dibs: Move event handling to dibs layer

Add defines for all event types and subtypes an ism device is known to
produce as it can be helpful for debugging purposes.

Introduces a generic 'struct dibs_event' and adopt ism device driver
and smc-d client accordingly. Tolerate and ignore other type and subtype
values to enable future device extensions.

SMC-D and ISM are now independent.
struct ism_dev can be moved to drivers/s390/net/ism.h.

Note that in smc, the term 'ism' is still used. Future patches could
replace that with 'dibs' or 'smc-d' as appropriate.

Signed-off-by: Julian Ruess <julianr@linux.ibm.com>
Co-developed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Link: https://patch.msgid.link/20250918110500.1731261-15-wintera@linux.ibm.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

2 files changed, 62 insertions, 15 deletions

diff --git a/include/linux/dibs.h b/include/linux/dibs.h
index be009c614205..c75607f8a5cf 100644
--- a/include/linux/dibs.h
+++ b/include/linux/dibs.h
@@ -67,6 +67,41 @@ struct dibs_dmb {
 	dma_addr_t dma_addr;
 };
 
+/* DIBS events
+ * -----------
+ * Dibs devices can optionally notify dibs clients about events that happened
+ * in the fabric or at the remote device or remote dmb.
+ */
+enum dibs_event_type {
+	/* Buffer event, e.g. a remote dmb was unregistered */
+	DIBS_BUF_EVENT,
+	/* Device event, e.g. a remote dibs device was disabled */
+	DIBS_DEV_EVENT,
+	/* Software event, a dibs client can send an event signal to a
+	 * remote dibs device.
+	 */
+	DIBS_SW_EVENT,
+	DIBS_OTHER_TYPE };
+
+enum dibs_event_subtype {
+	DIBS_BUF_UNREGISTERED,
+	DIBS_DEV_DISABLED,
+	DIBS_DEV_ERR_STATE,
+	DIBS_OTHER_SUBTYPE
+};
+
+struct dibs_event {
+	u32 type;
+	u32 subtype;
+	/* uuid_null if invalid */
+	uuid_t gid;
+	/* zero if invalid */
+	u64 buffer_tok;
+	u64 time;
+	/* additional data or zero */
+	u64 data;
+};
+
 struct dibs_dev;
 
 /* DIBS client
@@ -117,6 +152,15 @@ struct dibs_client_ops {
 	 */
 	void (*handle_irq)(struct dibs_dev *dev, unsigned int idx,
 			   u16 dmbemask);
+	/**
+	 * handle_event() - Handle control information sent by device
+	 * @dev: device reporting the event
+	 * @event: ism event structure
+	 *
+	 * * Context: Called in IRQ context by dibs device driver
+	 */
+	void (*handle_event)(struct dibs_dev *dev,
+			     const struct dibs_event *event);
 };
 
 struct dibs_client {
@@ -286,6 +330,24 @@ struct dibs_dev_ops {
 	 */
 	int (*del_vlan_id)(struct dibs_dev *dev, u64 vlan_id);
 	/**
+	 * signal_event() - trigger an event at a remote dibs device (optional)
+	 * @dev: local dibs device
+	 * @rgid: gid of remote dibs device
+	 * trigger_irq: zero: notification may be coalesced with other events
+	 *		non-zero: notify immediately
+	 * @subtype: 4 byte event code, meaning is defined by dibs client
+	 * @data: 8 bytes of additional information,
+	 *	  meaning is defined by dibs client
+	 *
+	 * dibs devices can offer support for sending a control event of type
+	 * EVENT_SWR to a remote dibs device.
+	 * NOTE: handle_event() will be called for all registered dibs clients
+	 * at the remote device.
+	 * Return: zero on success
+	 */
+	int (*signal_event)(struct dibs_dev *dev, const uuid_t *rgid,
+			    u32 trigger_irq, u32 event_code, u64 info);
+	/**
 	 * support_mmapped_rdmb() - can this device provide memory mapped
 	 *			    remote dmbs? (optional)
 	 * @dev: dibs device
diff --git a/include/net/smc.h b/include/net/smc.h
index 8e3debcf7db5..08bee529ed8d 100644
--- a/include/net/smc.h
+++ b/include/net/smc.h
@@ -16,7 +16,6 @@
 #include <linux/types.h>
 #include <linux/wait.h>
 #include <linux/dibs.h>
-#include "linux/ism.h"
 
 struct sock;
 
@@ -28,28 +27,14 @@ struct smc_hashinfo {
 };
 
 /* SMCD/ISM device driver interface */
-#define ISM_EVENT_DMB	0
-#define ISM_EVENT_GID	1
-#define ISM_EVENT_SWR	2
-
 #define ISM_RESERVED_VLANID	0x1FFF
 
-struct smcd_dev;
-
 struct smcd_gid {
 	u64	gid;
 	u64	gid_ext;
 };
 
-struct smcd_ops {
-	/* optional operations */
-	int (*signal_event)(struct smcd_dev *dev, struct smcd_gid *rgid,
-			    u32 trigger_irq, u32 event_code, u64 info);
-};
-
 struct smcd_dev {
-	const struct smcd_ops *ops;
-	void *priv;
 	struct dibs_dev *dibs;
 	struct list_head list;
 	spinlock_t lock;