diff mbox series

[RFC,net-next,1/7] net/ism: Create net/ism

Message ID 20250115195527.2094320-2-wintera@linux.ibm.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series Provide an ism layer | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net-next
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit fail Errors and warnings before: 1 this patch: 6
netdev/build_tools success Errors and warnings before: 0 (+1) this patch: 0 (+1)
netdev/cc_maintainers success CCed 13 of 13 maintainers
netdev/build_clang fail Errors and warnings before: 52 this patch: 57
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn fail Errors and warnings before: 5 this patch: 10
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 464 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Alexandra Winter Jan. 15, 2025, 7:55 p.m. UTC
Create an 'ISM' shim layer that will provide generic functionality and
declarations for ism device drivers and ism clients.

Move the respective pieces from drivers/s390/net/ism_drv.* to net/ism/

When we need to distinguish between generic ism interfaces and
specifically the s390 virtual pci ism device, it will be called 'ISM_vPCI'.

No optimizations are done in this patch, it only moves pieces around.
Following patch will further detangle ism_vpci and smc-d.

Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
---
 MAINTAINERS                |   7 ++
 drivers/s390/net/Kconfig   |   9 +--
 drivers/s390/net/Makefile  |   4 +-
 drivers/s390/net/ism_drv.c | 129 ++---------------------------
 include/linux/ism.h        |   8 ++
 include/net/smc.h          |   3 -
 net/Kconfig                |   1 +
 net/Makefile               |   1 +
 net/ism/Kconfig            |  14 ++++
 net/ism/Makefile           |   7 ++
 net/ism/ism_main.c         | 162 +++++++++++++++++++++++++++++++++++++
 11 files changed, 213 insertions(+), 132 deletions(-)
 create mode 100644 net/ism/Kconfig
 create mode 100644 net/ism/Makefile
 create mode 100644 net/ism/ism_main.c
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index 4dcb849e6748..780db61f3f16 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -12239,6 +12239,13 @@  F:	Documentation/devicetree/bindings/hwmon/renesas,isl28022.yaml
 F:	Documentation/hwmon/isl28022.rst
 F:	drivers/hwmon/isl28022.c
 
+ISM (INTERNAL SHARED MEMORY)
+M:	Alexandra Winter <wintera@linux.ibm.com>
+L:	netdev@vger.kernel.org
+S:	Supported
+F:	include/linux/ism.h
+F:	net/ism/
+
 ISOFS FILESYSTEM
 M:	Jan Kara <jack@suse.cz>
 L:	linux-fsdevel@vger.kernel.org
diff --git a/drivers/s390/net/Kconfig b/drivers/s390/net/Kconfig
index c61e6427384c..2e900d3087d4 100644
--- a/drivers/s390/net/Kconfig
+++ b/drivers/s390/net/Kconfig
@@ -100,15 +100,14 @@  config CCWGROUP
 	tristate
 	default (LCS || CTCM || QETH || SMC)
 
-config ISM
+config ISM_VPCI
 	tristate "Support for ISM vPCI Adapter"
-	depends on PCI
+	depends on PCI && ISM
 	imply SMC
-	default n
+	default y
 	help
 	  Select this option if you want to use the Internal Shared Memory
 	  vPCI Adapter. The adapter can be used with the SMC network protocol.
 
-	  To compile as a module choose M. The module name is ism.
-	  If unsure, choose N.
+	  To compile as a module choose M. The module name is ism_vpci.
 endmenu
diff --git a/drivers/s390/net/Makefile b/drivers/s390/net/Makefile
index bc55ec316adb..87461019184e 100644
--- a/drivers/s390/net/Makefile
+++ b/drivers/s390/net/Makefile
@@ -16,5 +16,5 @@  obj-$(CONFIG_QETH_L2) += qeth_l2.o
 qeth_l3-y += qeth_l3_main.o qeth_l3_sys.o
 obj-$(CONFIG_QETH_L3) += qeth_l3.o
 
-ism-y := ism_drv.o
-obj-$(CONFIG_ISM) += ism.o
+ism_vpci-y += ism_drv.o
+obj-$(CONFIG_ISM_VPCI) += ism_vpci.o
diff --git a/drivers/s390/net/ism_drv.c b/drivers/s390/net/ism_drv.c
index e36e3ea165d3..2eeccf5ef48d 100644
--- a/drivers/s390/net/ism_drv.c
+++ b/drivers/s390/net/ism_drv.c
@@ -4,7 +4,7 @@ 
  *
  * Copyright IBM Corp. 2018
  */
-#define KMSG_COMPONENT "ism"
+#define KMSG_COMPONENT "ism-vpci"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/module.h>
@@ -31,100 +31,7 @@  MODULE_DEVICE_TABLE(pci, ism_device_table);
 
 static debug_info_t *ism_debug_info;
 
-#define NO_CLIENT		0xff		/* must be >= MAX_CLIENTS */
-static struct ism_client *clients[MAX_CLIENTS];	/* use an array rather than */
-						/* a list for fast mapping  */
-static u8 max_client;
-static DEFINE_MUTEX(clients_lock);
 static bool ism_v2_capable;
-struct ism_dev_list {
-	struct list_head list;
-	struct mutex mutex; /* protects ism device list */
-};
-
-static struct ism_dev_list ism_dev_list = {
-	.list = LIST_HEAD_INIT(ism_dev_list.list),
-	.mutex = __MUTEX_INITIALIZER(ism_dev_list.mutex),
-};
-
-static void ism_setup_forwarding(struct ism_client *client, struct ism_dev *ism)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&ism->lock, flags);
-	ism->subs[client->id] = client;
-	spin_unlock_irqrestore(&ism->lock, flags);
-}
-
-int ism_register_client(struct ism_client *client)
-{
-	struct ism_dev *ism;
-	int i, rc = -ENOSPC;
-
-	mutex_lock(&ism_dev_list.mutex);
-	mutex_lock(&clients_lock);
-	for (i = 0; i < MAX_CLIENTS; ++i) {
-		if (!clients[i]) {
-			clients[i] = client;
-			client->id = i;
-			if (i == max_client)
-				max_client++;
-			rc = 0;
-			break;
-		}
-	}
-	mutex_unlock(&clients_lock);
-
-	if (i < MAX_CLIENTS) {
-		/* initialize with all devices that we got so far */
-		list_for_each_entry(ism, &ism_dev_list.list, list) {
-			ism->priv[i] = NULL;
-			client->add(ism);
-			ism_setup_forwarding(client, ism);
-		}
-	}
-	mutex_unlock(&ism_dev_list.mutex);
-
-	return rc;
-}
-EXPORT_SYMBOL_GPL(ism_register_client);
-
-int ism_unregister_client(struct ism_client *client)
-{
-	struct ism_dev *ism;
-	unsigned long flags;
-	int rc = 0;
-
-	mutex_lock(&ism_dev_list.mutex);
-	list_for_each_entry(ism, &ism_dev_list.list, list) {
-		spin_lock_irqsave(&ism->lock, flags);
-		/* Stop forwarding IRQs and events */
-		ism->subs[client->id] = NULL;
-		for (int i = 0; i < ISM_NR_DMBS; ++i) {
-			if (ism->sba_client_arr[i] == client->id) {
-				WARN(1, "%s: attempt to unregister '%s' with registered dmb(s)\n",
-				     __func__, client->name);
-				rc = -EBUSY;
-				goto err_reg_dmb;
-			}
-		}
-		spin_unlock_irqrestore(&ism->lock, flags);
-	}
-	mutex_unlock(&ism_dev_list.mutex);
-
-	mutex_lock(&clients_lock);
-	clients[client->id] = NULL;
-	if (client->id + 1 == max_client)
-		max_client--;
-	mutex_unlock(&clients_lock);
-	return rc;
-
-err_reg_dmb:
-	spin_unlock_irqrestore(&ism->lock, flags);
-	mutex_unlock(&ism_dev_list.mutex);
-	return rc;
-}
-EXPORT_SYMBOL_GPL(ism_unregister_client);
 
 static int ism_cmd(struct ism_dev *ism, void *cmd)
 {
@@ -475,7 +382,7 @@  static void ism_handle_event(struct ism_dev *ism)
 
 		entry = &ism->ieq->entry[ism->ieq_idx];
 		debug_event(ism_debug_info, 2, entry, sizeof(*entry));
-		for (i = 0; i < max_client; ++i) {
+		for (i = 0; i < MAX_CLIENTS; ++i) {
 			clt = ism->subs[i];
 			if (clt)
 				clt->handle_event(ism, entry);
@@ -524,7 +431,7 @@  static irqreturn_t ism_handle_irq(int irq, void *data)
 static int ism_dev_init(struct ism_dev *ism)
 {
 	struct pci_dev *pdev = ism->pdev;
-	int i, ret;
+	int ret;
 
 	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
 	if (ret <= 0)
@@ -558,19 +465,7 @@  static int ism_dev_init(struct ism_dev *ism)
 	else
 		ism_v2_capable = false;
 
-	mutex_lock(&ism_dev_list.mutex);
-	mutex_lock(&clients_lock);
-	for (i = 0; i < max_client; ++i) {
-		if (clients[i]) {
-			clients[i]->add(ism);
-			ism_setup_forwarding(clients[i], ism);
-		}
-	}
-	mutex_unlock(&clients_lock);
-
-	list_add(&ism->list, &ism_dev_list.list);
-	mutex_unlock(&ism_dev_list.mutex);
-
+	ism_dev_register(ism);
 	query_info(ism);
 	return 0;
 
@@ -649,17 +544,11 @@  static void ism_dev_exit(struct ism_dev *ism)
 	int i;
 
 	spin_lock_irqsave(&ism->lock, flags);
-	for (i = 0; i < max_client; ++i)
+	for (i = 0; i < MAX_CLIENTS; ++i)
 		ism->subs[i] = NULL;
 	spin_unlock_irqrestore(&ism->lock, flags);
 
-	mutex_lock(&ism_dev_list.mutex);
-	mutex_lock(&clients_lock);
-	for (i = 0; i < max_client; ++i) {
-		if (clients[i])
-			clients[i]->remove(ism);
-	}
-	mutex_unlock(&clients_lock);
+	ism_dev_unregister(ism);
 
 	if (ism_v2_capable)
 		ism_del_vlan_id(ism, ISM_RESERVED_VLANID);
@@ -668,8 +557,6 @@  static void ism_dev_exit(struct ism_dev *ism)
 	free_irq(pci_irq_vector(pdev, 0), ism);
 	kfree(ism->sba_client_arr);
 	pci_free_irq_vectors(pdev);
-	list_del_init(&ism->list);
-	mutex_unlock(&ism_dev_list.mutex);
 }
 
 static void ism_remove(struct pci_dev *pdev)
@@ -700,8 +587,6 @@  static int __init ism_init(void)
 	if (!ism_debug_info)
 		return -ENODEV;
 
-	memset(clients, 0, sizeof(clients));
-	max_client = 0;
 	debug_register_view(ism_debug_info, &debug_hex_ascii_view);
 	ret = pci_register_driver(&ism_driver);
 	if (ret)
@@ -721,7 +606,7 @@  module_exit(ism_exit);
 
 /*************************** SMC-D Implementation *****************************/
 
-#if IS_ENABLED(CONFIG_SMC)
+#if IS_ENABLED(CONFIG_SMC) // needed to avoid unused functions
 static int ism_query_rgid(struct ism_dev *ism, u64 rgid, u32 vid_valid,
 			  u32 vid)
 {
diff --git a/include/linux/ism.h b/include/linux/ism.h
index 5428edd90982..1462296e8ba7 100644
--- a/include/linux/ism.h
+++ b/include/linux/ism.h
@@ -9,6 +9,7 @@ 
 #ifndef _ISM_H
 #define _ISM_H
 
+#include <linux/device.h>
 #include <linux/workqueue.h>
 
 struct ism_dmb {
@@ -24,6 +25,7 @@  struct ism_dmb {
 
 /* Unless we gain unexpected popularity, this limit should hold for a while */
 #define MAX_CLIENTS		8
+#define NO_CLIENT		0xff		/* must be >= MAX_CLIENTS */
 #define ISM_NR_DMBS		1920
 
 struct ism_dev {
@@ -76,6 +78,9 @@  static inline void *ism_get_priv(struct ism_dev *dev,
 	return dev->priv[client->id];
 }
 
+int ism_dev_register(struct ism_dev *ism);
+void ism_dev_unregister(struct ism_dev *ism);
+
 static inline void ism_set_priv(struct ism_dev *dev, struct ism_client *client,
 				void *priv) {
 	dev->priv[client->id] = priv;
@@ -87,6 +92,9 @@  int  ism_unregister_dmb(struct ism_dev *dev, struct ism_dmb *dmb);
 int  ism_move(struct ism_dev *dev, u64 dmb_tok, unsigned int idx, bool sf,
 	      unsigned int offset, void *data, unsigned int size);
 
+#define ISM_RESERVED_VLANID	0x1FFF
+#define ISM_ERROR	0xFFFF
+
 const struct smcd_ops *ism_get_smcd_ops(void);
 
 #endif	/* _ISM_H */
diff --git a/include/net/smc.h b/include/net/smc.h
index db84e4e35080..ab732b286f91 100644
--- a/include/net/smc.h
+++ b/include/net/smc.h
@@ -42,9 +42,6 @@  struct smcd_dmb {
 #define ISM_EVENT_GID	1
 #define ISM_EVENT_SWR	2
 
-#define ISM_RESERVED_VLANID	0x1FFF
-
-#define ISM_ERROR	0xFFFF
 
 struct smcd_dev;
 
diff --git a/net/Kconfig b/net/Kconfig
index c3fca69a7c83..2dbe9655f7de 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -83,6 +83,7 @@  source "net/tls/Kconfig"
 source "net/xfrm/Kconfig"
 source "net/iucv/Kconfig"
 source "net/smc/Kconfig"
+source "net/ism/Kconfig"
 source "net/xdp/Kconfig"
 
 config NET_HANDSHAKE
diff --git a/net/Makefile b/net/Makefile
index 60ed5190eda8..6f06cf00bfbb 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -51,6 +51,7 @@  obj-$(CONFIG_TIPC)		+= tipc/
 obj-$(CONFIG_NETLABEL)		+= netlabel/
 obj-$(CONFIG_IUCV)		+= iucv/
 obj-$(CONFIG_SMC)		+= smc/
+obj-$(CONFIG_ISM)		+= ism/
 obj-$(CONFIG_RFKILL)		+= rfkill/
 obj-$(CONFIG_NET_9P)		+= 9p/
 obj-$(CONFIG_CAIF)		+= caif/
diff --git a/net/ism/Kconfig b/net/ism/Kconfig
new file mode 100644
index 000000000000..4329489cc1e9
--- /dev/null
+++ b/net/ism/Kconfig
@@ -0,0 +1,14 @@ 
+# SPDX-License-Identifier: GPL-2.0
+config ISM
+	tristate "ISM support"
+	default n
+	help
+	  Internal Shared Memory (ISM)
+	  A communication method that uses common physical memory for
+	  synchronous direct access into a remote buffer.
+
+	  Select this option to provide the abstraction layer between
+	  ISM devices and ISM users like the SMC protocol.
+
+	  To compile as a module choose M. The module name is ism.
+	  If unsure, choose N.
diff --git a/net/ism/Makefile b/net/ism/Makefile
new file mode 100644
index 000000000000..b752baf72003
--- /dev/null
+++ b/net/ism/Makefile
@@ -0,0 +1,7 @@ 
+# SPDX-License-Identifier: GPL-2.0
+#
+# ISM class module
+#
+
+ism-y += ism_main.o
+obj-$(CONFIG_ISM) += ism.o
diff --git a/net/ism/ism_main.c b/net/ism/ism_main.c
new file mode 100644
index 000000000000..268408dbd691
--- /dev/null
+++ b/net/ism/ism_main.c
@@ -0,0 +1,162 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Internal Shared Memory
+ *
+ *  Implementation of the ISM class module
+ *
+ *  Copyright IBM Corp. 2024
+ */
+#define KMSG_COMPONENT "ism"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/err.h>
+#include <linux/ism.h>
+
+MODULE_DESCRIPTION("Internal Shared Memory class");
+MODULE_LICENSE("GPL");
+
+static struct ism_client *clients[MAX_CLIENTS];	/* use an array rather than */
+						/* a list for fast mapping  */
+static u8 max_client;
+static DEFINE_MUTEX(clients_lock);
+struct ism_dev_list {
+	struct list_head list;
+	struct mutex mutex; /* protects ism device list */
+};
+
+static struct ism_dev_list ism_dev_list = {
+	.list = LIST_HEAD_INIT(ism_dev_list.list),
+	.mutex = __MUTEX_INITIALIZER(ism_dev_list.mutex),
+};
+
+static void ism_setup_forwarding(struct ism_client *client, struct ism_dev *ism)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&ism->lock, flags);
+	ism->subs[client->id] = client;
+	spin_unlock_irqrestore(&ism->lock, flags);
+}
+
+int ism_register_client(struct ism_client *client)
+{
+	struct ism_dev *ism;
+	int i, rc = -ENOSPC;
+
+	mutex_lock(&ism_dev_list.mutex);
+	mutex_lock(&clients_lock);
+	for (i = 0; i < MAX_CLIENTS; ++i) {
+		if (!clients[i]) {
+			clients[i] = client;
+			client->id = i;
+			if (i == max_client)
+				max_client++;
+			rc = 0;
+			break;
+		}
+	}
+	mutex_unlock(&clients_lock);
+
+	if (i < MAX_CLIENTS) {
+		/* initialize with all devices that we got so far */
+		list_for_each_entry(ism, &ism_dev_list.list, list) {
+			ism->priv[i] = NULL;
+			client->add(ism);
+			ism_setup_forwarding(client, ism);
+		}
+	}
+	mutex_unlock(&ism_dev_list.mutex);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ism_register_client);
+
+int ism_unregister_client(struct ism_client *client)
+{
+	struct ism_dev *ism;
+	unsigned long flags;
+	int rc = 0;
+
+	mutex_lock(&ism_dev_list.mutex);
+	list_for_each_entry(ism, &ism_dev_list.list, list) {
+		spin_lock_irqsave(&ism->lock, flags);
+		/* Stop forwarding IRQs and events */
+		ism->subs[client->id] = NULL;
+		for (int i = 0; i < ISM_NR_DMBS; ++i) {
+			if (ism->sba_client_arr[i] == client->id) {
+				WARN(1, "%s: attempt to unregister '%s' with registered dmb(s)\n",
+				     __func__, client->name);
+				rc = -EBUSY;
+				goto err_reg_dmb;
+			}
+		}
+		spin_unlock_irqrestore(&ism->lock, flags);
+	}
+	mutex_unlock(&ism_dev_list.mutex);
+
+	mutex_lock(&clients_lock);
+	clients[client->id] = NULL;
+	if (client->id + 1 == max_client)
+		max_client--;
+	mutex_unlock(&clients_lock);
+	return rc;
+
+err_reg_dmb:
+	spin_unlock_irqrestore(&ism->lock, flags);
+	mutex_unlock(&ism_dev_list.mutex);
+	return rc;
+}
+EXPORT_SYMBOL_GPL(ism_unregister_client);
+
+int ism_dev_register(struct ism_dev *ism)
+{
+	int i;
+
+	mutex_lock(&ism_dev_list.mutex);
+	mutex_lock(&clients_lock);
+	for (i = 0; i < max_client; ++i) {
+		if (clients[i]) {
+			clients[i]->add(ism);
+			ism_setup_forwarding(clients[i], ism);
+		}
+	}
+	mutex_unlock(&clients_lock);
+	list_add(&ism->list, &ism_dev_list.list);
+	mutex_unlock(&ism_dev_list.mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(ism_dev_register);
+
+void ism_dev_unregister(struct ism_dev *ism)
+{
+	int i;
+
+	mutex_lock(&ism_dev_list.mutex);
+	mutex_lock(&clients_lock);
+	for (i = 0; i < max_client; ++i) {
+		if (clients[i])
+			clients[i]->remove(ism);
+	}
+	mutex_unlock(&clients_lock);
+	list_del_init(&ism->list);
+	mutex_unlock(&ism_dev_list.mutex);
+}
+EXPORT_SYMBOL_GPL(ism_dev_unregister);
+
+static int __init ism_init(void)
+{
+	memset(clients, 0, sizeof(clients));
+	max_client = 0;
+
+	return 0;
+}
+
+static void __exit ism_exit(void)
+{
+}
+
+module_init(ism_init);
+module_exit(ism_exit);