diff mbox series

[RFC,net-next,v5,02/11] net/smc: introduce loopback-ism for SMC intra-OS shortcut

Message ID 20240324135522.108564-3-guwen@linux.alibaba.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series net/smc: SMC intra-OS shortcut with loopback-ism | 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 success Errors and warnings before: 950 this patch: 950
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 10 of 10 maintainers
netdev/build_clang success Errors and warnings before: 956 this patch: 956
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 success Errors and warnings before: 962 this patch: 962
netdev/checkpatch warning WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
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

Wen Gu March 24, 2024, 1:55 p.m. UTC 
This introduces a kind of Emulated-ISM device named loopback-ism for
SMCv2.1. The loopback-ism device is currently exclusive for SMC usage,
and aims to provide an SMC shortcut for sockets within the same kernel,
leading to improved intra-OS traffic performance. Configuration of this
feature is managed through the config SMC_LO.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
 net/smc/Kconfig        |  13 ++++
 net/smc/Makefile       |   2 +-
 net/smc/af_smc.c       |  12 ++-
 net/smc/smc_loopback.c | 164 +++++++++++++++++++++++++++++++++++++++++
 net/smc/smc_loopback.h |  33 +++++++++
 5 files changed, 222 insertions(+), 2 deletions(-)
 create mode 100644 net/smc/smc_loopback.c
 create mode 100644 net/smc/smc_loopback.h

Comments

Gerd Bayer April 3, 2024, 11:27 a.m. UTC | #1 
On Sun, 2024-03-24 at 21:55 +0800, Wen Gu wrote:
> Configuration of this feature is managed through the config SMC_LO.

Hi Wen,

you could omit building smc_loopback.o if CONFIG_SMC_LO was not set if
you included the following fixup-patch. I think it's cleaner to put a
few parts of net/smc/af_smc.c under conditional compile rather than
have most of the contents of net/smc/smc_loopback.c under #ifdef.

>From 11a9cfce550f0c4df10eafdd30aa4226d4d522a8 Mon Sep 17 00:00:00 2001
From: Gerd Bayer <gbayer@linux.ibm.com>
Date: Wed, 3 Apr 2024 11:43:36 +0200
Subject: [PATCH] fixup! net/smc: introduce loopback-ism for SMC intra-
OS
 shortcut

---
 net/smc/Makefile       | 5 +++--
 net/smc/af_smc.c       | 6 ++++++
 net/smc/smc_loopback.c | 8 --------
 3 files changed, 9 insertions(+), 10 deletions(-)

diff --git a/net/smc/Makefile b/net/smc/Makefile
index a8c37111abe1..3b73c9d561bb 100644
--- a/net/smc/Makefile
+++ b/net/smc/Makefile
@@ -4,5 +4,6 @@ obj-$(CONFIG_SMC)	+= smc.o
 obj-$(CONFIG_SMC_DIAG)	+= smc_diag.o
 smc-y := af_smc.o smc_pnet.o smc_ib.o smc_clc.o smc_core.o smc_wr.o
smc_llc.o
 smc-y += smc_cdc.o smc_tx.o smc_rx.o smc_close.o smc_ism.o
smc_netlink.o smc_stats.o
-smc-y += smc_tracepoint.o smc_loopback.o
-smc-$(CONFIG_SYSCTL) += smc_sysctl.o
+smc-y += smc_tracepoint.o
+smc-$(CONFIG_SMC_LO)	+= smc_loopback.o
+smc-$(CONFIG_SYSCTL)	+= smc_sysctl.o
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index fce7a5b2ce5c..bcbf600cd271 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -3574,11 +3574,13 @@ static int __init smc_init(void)
 		goto out_sock;
 	}
 
+#if IS_ENABLED(CONFIG_SMC_LO)
 	rc = smc_loopback_init();
 	if (rc) {
 		pr_err("%s: smc_loopback_init fails with %d\n",
__func__, rc);
 		goto out_ib;
 	}
+#endif
 
 	rc = tcp_register_ulp(&smc_ulp_ops);
 	if (rc) {
@@ -3590,8 +3592,10 @@ static int __init smc_init(void)
 	return 0;
 
 out_lo:
+#if IS_ENABLED(CONFIG_SMC_LO)
 	smc_loopback_exit();
 out_ib:
+#endif
 	smc_ib_unregister_client();
 out_sock:
 	sock_unregister(PF_SMC);
@@ -3628,7 +3632,9 @@ static void __exit smc_exit(void)
 	tcp_unregister_ulp(&smc_ulp_ops);
 	sock_unregister(PF_SMC);
 	smc_core_exit();
+#if IS_ENABLED(CONFIG_SMC_LO)
 	smc_loopback_exit();
+#endif
 	smc_ib_unregister_client();
 	smc_ism_exit();
 	destroy_workqueue(smc_close_wq);
diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
index 994fe39930ad..8d0181635ded 100644
--- a/net/smc/smc_loopback.c
+++ b/net/smc/smc_loopback.c
@@ -19,7 +19,6 @@
 #include "smc_ism.h"
 #include "smc_loopback.h"
 
-#if IS_ENABLED(CONFIG_SMC_LO)
 #define SMC_LO_V2_CAPABLE	0x1 /* loopback-ism acts as ISMv2 */
 #define SMC_LO_SUPPORT_NOCOPY	0x1
 #define SMC_DMA_ADDR_INVALID	(~(dma_addr_t)0)
@@ -442,20 +441,13 @@ static void smc_lo_dev_remove(void)
 	smc_lo_dev_exit(lo_dev);
 	put_device(&lo_dev->dev); /* device_initialize in
smc_lo_dev_probe */
 }
-#endif
 
 int smc_loopback_init(void)
 {
-#if IS_ENABLED(CONFIG_SMC_LO)
 	return smc_lo_dev_probe();
-#else
-	return 0;
-#endif
 }
 
 void smc_loopback_exit(void)
 {
-#if IS_ENABLED(CONFIG_SMC_LO)
 	smc_lo_dev_remove();
-#endif
 }
Wen Gu April 4, 2024, 8:46 a.m. UTC | #2 
On 2024/4/3 19:27, Gerd Bayer wrote:
> On Sun, 2024-03-24 at 21:55 +0800, Wen Gu wrote:
>> Configuration of this feature is managed through the config SMC_LO.
> 
> Hi Wen,
> 
> you could omit building smc_loopback.o if CONFIG_SMC_LO was not set if
> you included the following fixup-patch. I think it's cleaner to put a
> few parts of net/smc/af_smc.c under conditional compile rather than
> have most of the contents of net/smc/smc_loopback.c under #ifdef.
> 

Hi Gerd. That is a really good suggestion. It is much cleaner in this way.
I will improve it in next version. Thank you very much!

>  From 11a9cfce550f0c4df10eafdd30aa4226d4d522a8 Mon Sep 17 00:00:00 2001
> From: Gerd Bayer <gbayer@linux.ibm.com>
> Date: Wed, 3 Apr 2024 11:43:36 +0200
> Subject: [PATCH] fixup! net/smc: introduce loopback-ism for SMC intra-
> OS
>   shortcut
> 
> ---
>   net/smc/Makefile       | 5 +++--
>   net/smc/af_smc.c       | 6 ++++++
>   net/smc/smc_loopback.c | 8 --------
>   3 files changed, 9 insertions(+), 10 deletions(-)
> 
> diff --git a/net/smc/Makefile b/net/smc/Makefile
> index a8c37111abe1..3b73c9d561bb 100644
> --- a/net/smc/Makefile
> +++ b/net/smc/Makefile
> @@ -4,5 +4,6 @@ obj-$(CONFIG_SMC)	+= smc.o
>   obj-$(CONFIG_SMC_DIAG)	+= smc_diag.o
>   smc-y := af_smc.o smc_pnet.o smc_ib.o smc_clc.o smc_core.o smc_wr.o
> smc_llc.o
>   smc-y += smc_cdc.o smc_tx.o smc_rx.o smc_close.o smc_ism.o
> smc_netlink.o smc_stats.o
> -smc-y += smc_tracepoint.o smc_loopback.o
> -smc-$(CONFIG_SYSCTL) += smc_sysctl.o
> +smc-y += smc_tracepoint.o
> +smc-$(CONFIG_SMC_LO)	+= smc_loopback.o
> +smc-$(CONFIG_SYSCTL)	+= smc_sysctl.o
> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
> index fce7a5b2ce5c..bcbf600cd271 100644
> --- a/net/smc/af_smc.c
> +++ b/net/smc/af_smc.c
> @@ -3574,11 +3574,13 @@ static int __init smc_init(void)
>   		goto out_sock;
>   	}
>   
> +#if IS_ENABLED(CONFIG_SMC_LO)
>   	rc = smc_loopback_init();
>   	if (rc) {
>   		pr_err("%s: smc_loopback_init fails with %d\n",
> __func__, rc);
>   		goto out_ib;
>   	}
> +#endif
>   
>   	rc = tcp_register_ulp(&smc_ulp_ops);
>   	if (rc) {
> @@ -3590,8 +3592,10 @@ static int __init smc_init(void)
>   	return 0;
>   
>   out_lo:
> +#if IS_ENABLED(CONFIG_SMC_LO)
>   	smc_loopback_exit();
>   out_ib:
> +#endif
>   	smc_ib_unregister_client();
>   out_sock:
>   	sock_unregister(PF_SMC);
> @@ -3628,7 +3632,9 @@ static void __exit smc_exit(void)
>   	tcp_unregister_ulp(&smc_ulp_ops);
>   	sock_unregister(PF_SMC);
>   	smc_core_exit();
> +#if IS_ENABLED(CONFIG_SMC_LO)
>   	smc_loopback_exit();
> +#endif
>   	smc_ib_unregister_client();
>   	smc_ism_exit();
>   	destroy_workqueue(smc_close_wq);
> diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
> index 994fe39930ad..8d0181635ded 100644
> --- a/net/smc/smc_loopback.c
> +++ b/net/smc/smc_loopback.c
> @@ -19,7 +19,6 @@
>   #include "smc_ism.h"
>   #include "smc_loopback.h"
>   
> -#if IS_ENABLED(CONFIG_SMC_LO)
>   #define SMC_LO_V2_CAPABLE	0x1 /* loopback-ism acts as ISMv2 */
>   #define SMC_LO_SUPPORT_NOCOPY	0x1
>   #define SMC_DMA_ADDR_INVALID	(~(dma_addr_t)0)
> @@ -442,20 +441,13 @@ static void smc_lo_dev_remove(void)
>   	smc_lo_dev_exit(lo_dev);
>   	put_device(&lo_dev->dev); /* device_initialize in
> smc_lo_dev_probe */
>   }
> -#endif
>   
>   int smc_loopback_init(void)
>   {
> -#if IS_ENABLED(CONFIG_SMC_LO)
>   	return smc_lo_dev_probe();
> -#else
> -	return 0;
> -#endif
>   }
>   
>   void smc_loopback_exit(void)
>   {
> -#if IS_ENABLED(CONFIG_SMC_LO)
>   	smc_lo_dev_remove();
> -#endif
>   }
diff mbox series

Patch

diff --git a/net/smc/Kconfig b/net/smc/Kconfig
index 746be3996768..ba5e6a2dd2fd 100644
--- a/net/smc/Kconfig
+++ b/net/smc/Kconfig
@@ -20,3 +20,16 @@  config SMC_DIAG
 	  smcss.
 
 	  if unsure, say Y.
+
+config SMC_LO
+	bool "SMC intra-OS shortcut with loopback-ism"
+	depends on SMC
+	default n
+	help
+	  SMC_LO enables the creation of an Emulated-ISM device named
+	  loopback-ism in SMC and makes use of it for transferring data
+	  when communication occurs within the same OS. This helps in
+	  convenient testing of SMC-D since loopback-ism is independent
+	  of architecture or hardware.
+
+	  if unsure, say N.
diff --git a/net/smc/Makefile b/net/smc/Makefile
index 875efcd126a2..a8c37111abe1 100644
--- a/net/smc/Makefile
+++ b/net/smc/Makefile
@@ -4,5 +4,5 @@  obj-$(CONFIG_SMC)	+= smc.o
 obj-$(CONFIG_SMC_DIAG)	+= smc_diag.o
 smc-y := af_smc.o smc_pnet.o smc_ib.o smc_clc.o smc_core.o smc_wr.o smc_llc.o
 smc-y += smc_cdc.o smc_tx.o smc_rx.o smc_close.o smc_ism.o smc_netlink.o smc_stats.o
-smc-y += smc_tracepoint.o
+smc-y += smc_tracepoint.o smc_loopback.o
 smc-$(CONFIG_SYSCTL) += smc_sysctl.o
diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 4b52b3b159c0..751a8fdd6eb0 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -53,6 +53,7 @@ 
 #include "smc_stats.h"
 #include "smc_tracepoint.h"
 #include "smc_sysctl.h"
+#include "smc_loopback.h"
 
 static DEFINE_MUTEX(smc_server_lgr_pending);	/* serialize link group
 						 * creation on server
@@ -3557,15 +3558,23 @@  static int __init smc_init(void)
 		goto out_sock;
 	}
 
+	rc = smc_loopback_init();
+	if (rc) {
+		pr_err("%s: smc_loopback_init fails with %d\n", __func__, rc);
+		goto out_ib;
+	}
+
 	rc = tcp_register_ulp(&smc_ulp_ops);
 	if (rc) {
 		pr_err("%s: tcp_ulp_register fails with %d\n", __func__, rc);
-		goto out_ib;
+		goto out_lo;
 	}
 
 	static_branch_enable(&tcp_have_smc);
 	return 0;
 
+out_lo:
+	smc_loopback_exit();
 out_ib:
 	smc_ib_unregister_client();
 out_sock:
@@ -3603,6 +3612,7 @@  static void __exit smc_exit(void)
 	tcp_unregister_ulp(&smc_ulp_ops);
 	sock_unregister(PF_SMC);
 	smc_core_exit();
+	smc_loopback_exit();
 	smc_ib_unregister_client();
 	smc_ism_exit();
 	destroy_workqueue(smc_close_wq);
diff --git a/net/smc/smc_loopback.c b/net/smc/smc_loopback.c
new file mode 100644
index 000000000000..3990f689ae79
--- /dev/null
+++ b/net/smc/smc_loopback.c
@@ -0,0 +1,164 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  Shared Memory Communications Direct over loopback-ism device.
+ *
+ *  Functions for loopback-ism device.
+ *
+ *  Copyright (c) 2024, Alibaba Inc.
+ *
+ *  Author: Wen Gu <guwen@linux.alibaba.com>
+ *          Tony Lu <tonylu@linux.alibaba.com>
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/types.h>
+#include <net/smc.h>
+
+#include "smc_ism.h"
+#include "smc_loopback.h"
+
+#if IS_ENABLED(CONFIG_SMC_LO)
+static const char smc_lo_dev_name[] = "loopback-ism";
+static struct smc_lo_dev *lo_dev;
+
+static const struct smcd_ops lo_ops = {
+	.query_remote_gid	= NULL,
+	.register_dmb		= NULL,
+	.unregister_dmb		= NULL,
+	.add_vlan_id		= NULL,
+	.del_vlan_id		= NULL,
+	.set_vlan_required	= NULL,
+	.reset_vlan_required	= NULL,
+	.signal_event		= NULL,
+	.move_data		= NULL,
+	.supports_v2		= NULL,
+	.get_local_gid		= NULL,
+	.get_chid		= NULL,
+	.get_dev		= NULL,
+};
+
+static struct smcd_dev *smcd_lo_alloc_dev(const struct smcd_ops *ops,
+					  int max_dmbs)
+{
+	struct smcd_dev *smcd;
+
+	smcd = kzalloc(sizeof(*smcd), GFP_KERNEL);
+	if (!smcd)
+		return NULL;
+
+	smcd->conn = kcalloc(max_dmbs, sizeof(struct smc_connection *),
+			     GFP_KERNEL);
+	if (!smcd->conn)
+		goto out_smcd;
+
+	smcd->ops = ops;
+
+	spin_lock_init(&smcd->lock);
+	spin_lock_init(&smcd->lgr_lock);
+	INIT_LIST_HEAD(&smcd->vlan);
+	INIT_LIST_HEAD(&smcd->lgr_list);
+	init_waitqueue_head(&smcd->lgrs_deleted);
+	return smcd;
+
+out_smcd:
+	kfree(smcd);
+	return NULL;
+}
+
+static int smcd_lo_register_dev(struct smc_lo_dev *ldev)
+{
+	struct smcd_dev *smcd;
+
+	smcd = smcd_lo_alloc_dev(&lo_ops, SMC_LO_MAX_DMBS);
+	if (!smcd)
+		return -ENOMEM;
+	ldev->smcd = smcd;
+	smcd->priv = ldev;
+
+	/* TODO:
+	 * register loopback-ism to smcd_dev list.
+	 */
+	return 0;
+}
+
+static void smcd_lo_unregister_dev(struct smc_lo_dev *ldev)
+{
+	struct smcd_dev *smcd = ldev->smcd;
+
+	/* TODO:
+	 * unregister loopback-ism from smcd_dev list.
+	 */
+	kfree(smcd->conn);
+	kfree(smcd);
+}
+
+static int smc_lo_dev_init(struct smc_lo_dev *ldev)
+{
+	return smcd_lo_register_dev(ldev);
+}
+
+static void smc_lo_dev_exit(struct smc_lo_dev *ldev)
+{
+	smcd_lo_unregister_dev(ldev);
+}
+
+static void smc_lo_dev_release(struct device *dev)
+{
+	struct smc_lo_dev *ldev =
+		container_of(dev, struct smc_lo_dev, dev);
+
+	kfree(ldev);
+}
+
+static int smc_lo_dev_probe(void)
+{
+	struct smc_lo_dev *ldev;
+	int ret;
+
+	ldev = kzalloc(sizeof(*ldev), GFP_KERNEL);
+	if (!ldev)
+		return -ENOMEM;
+
+	ldev->dev.parent = NULL;
+	ldev->dev.release = smc_lo_dev_release;
+	device_initialize(&ldev->dev);
+	dev_set_name(&ldev->dev, smc_lo_dev_name);
+
+	ret = smc_lo_dev_init(ldev);
+	if (ret)
+		goto free_dev;
+
+	lo_dev = ldev; /* global loopback device */
+	return 0;
+
+free_dev:
+	put_device(&ldev->dev);
+	return ret;
+}
+
+static void smc_lo_dev_remove(void)
+{
+	if (!lo_dev)
+		return;
+
+	smc_lo_dev_exit(lo_dev);
+	put_device(&lo_dev->dev); /* device_initialize in smc_lo_dev_probe */
+}
+#endif
+
+int smc_loopback_init(void)
+{
+#if IS_ENABLED(CONFIG_SMC_LO)
+	return smc_lo_dev_probe();
+#else
+	return 0;
+#endif
+}
+
+void smc_loopback_exit(void)
+{
+#if IS_ENABLED(CONFIG_SMC_LO)
+	smc_lo_dev_remove();
+#endif
+}
diff --git a/net/smc/smc_loopback.h b/net/smc/smc_loopback.h
new file mode 100644
index 000000000000..77980650b2bd
--- /dev/null
+++ b/net/smc/smc_loopback.h
@@ -0,0 +1,33 @@ 
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ *  Shared Memory Communications Direct over loopback-ism device.
+ *
+ *  SMC-D loopback-ism device structure definitions.
+ *
+ *  Copyright (c) 2024, Alibaba Inc.
+ *
+ *  Author: Wen Gu <guwen@linux.alibaba.com>
+ *          Tony Lu <tonylu@linux.alibaba.com>
+ *
+ */
+
+#ifndef _SMC_LOOPBACK_H
+#define _SMC_LOOPBACK_H
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <net/smc.h>
+
+#if IS_ENABLED(CONFIG_SMC_LO)
+#define SMC_LO_MAX_DMBS		5000
+
+struct smc_lo_dev {
+	struct smcd_dev *smcd;
+	struct device dev;
+};
+#endif
+
+int smc_loopback_init(void);
+void smc_loopback_exit(void);
+
+#endif /* _SMC_LOOPBACK_H */