@@ -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 {
@@ -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)
{
@@ -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);
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(+)