diff mbox series

[net-next,14/18] net/smc: add operation for getting DMB attribute

Message ID 1695134522-126655-15-git-send-email-guwen@linux.alibaba.com (mailing list archive)
State Superseded
Delegated to: Netdev Maintainers
Headers show
Series net/smc: implement virtual ISM extension and loopback-ism | expand

Checks

Context Check Description
netdev/series_format fail Series longer than 15 patches (and no cover letter)
netdev/tree_selection success Clearly marked for net-next
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: 1343 this patch: 1343
netdev/cc_maintainers success CCed 12 of 12 maintainers
netdev/build_clang success Errors and warnings before: 1366 this patch: 1366
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: 1366 this patch: 1366
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 38 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Wen Gu Sept. 19, 2023, 2:41 p.m. UTC 
On s390, ISM devices are used on machine level hypervisors which is a
partitioning hypervisor without paging. The sndbufs and peer DMBs in such
case can't be mapped to the same physical memory.

However in other cases, such as communication within the same OS instance
with loopback, the sndbufs and peer DMBs can be mapped to the same physical
memory to avoid memory copy from sndbufs to peer DMBs.

So this patch introduces an operation to smcd_ops to judge whether the
sndbufs-DMB map is available. And for reuse, the interface is designed to
return DMB attribute, not only the sndbuf-DMB map feature.

Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
---
 include/net/smc.h | 5 +++++
 net/smc/smc_ism.c | 8 ++++++++
 net/smc/smc_ism.h | 1 +
 3 files changed, 14 insertions(+)
diff mbox series

Patch

diff --git a/include/net/smc.h b/include/net/smc.h
index 389d26d..6930c8a 100644
--- a/include/net/smc.h
+++ b/include/net/smc.h
@@ -55,6 +55,10 @@  struct smcd_seid {
 
 #define ISM_ERROR	0xFFFF
 
+enum {
+	ISM_ATTR_DMB_MAP = 0,
+};
+
 struct smcd_dev;
 
 struct smcd_gid {
@@ -82,6 +86,7 @@  struct smcd_ops {
 	void (*get_local_gid)(struct smcd_dev *dev, struct smcd_gid *gid);
 	u16 (*get_chid)(struct smcd_dev *dev);
 	struct device* (*get_dev)(struct smcd_dev *dev);
+	int (*get_dev_attr)(struct smcd_dev *dev);
 };
 
 struct smcd_dev {
diff --git a/net/smc/smc_ism.c b/net/smc/smc_ism.c
index ba37b27..14e018c 100644
--- a/net/smc/smc_ism.c
+++ b/net/smc/smc_ism.c
@@ -214,6 +214,14 @@  int smc_ism_unregister_dmb(struct smcd_dev *smcd, struct smc_buf_desc *dmb_desc)
 	return rc;
 }
 
+bool smc_ism_dmb_mappable(struct smcd_dev *smcd)
+{
+	if (smcd->ops->get_dev_attr &&
+	    (smcd->ops->get_dev_attr(smcd) & BIT(ISM_ATTR_DMB_MAP)))
+		return true;
+	return false;
+}
+
 int smc_ism_register_dmb(struct smc_link_group *lgr, int dmb_len,
 			 struct smc_buf_desc *dmb_desc)
 {
diff --git a/net/smc/smc_ism.h b/net/smc/smc_ism.h
index 7ab82dd..cef212c 100644
--- a/net/smc/smc_ism.h
+++ b/net/smc/smc_ism.h
@@ -44,6 +44,7 @@  int smc_ism_cantalk(struct smcd_gid *peer_gid, unsigned short vlan_id,
 int smc_ism_register_dmb(struct smc_link_group *lgr, int buf_size,
 			 struct smc_buf_desc *dmb_desc);
 int smc_ism_unregister_dmb(struct smcd_dev *dev, struct smc_buf_desc *dmb_desc);
+bool smc_ism_dmb_mappable(struct smcd_dev *smcd);
 int smc_ism_signal_shutdown(struct smc_link_group *lgr);
 void smc_ism_get_system_eid(u8 **eid);
 u16 smc_ism_get_chid(struct smcd_dev *dev);