[PATCH v2 rdma-next] RDMA/qedr: Add kernel capability flags for dpm enabled mode

[PATCH v2 rdma-next] RDMA/qedr: Add kernel capability flags for dpm enabled mode

[Michal Kalderon]

HW/FW support two types of latency enhancement features.
Until now user-space implemented only edpm (enhanced dpm).
We add kernel capability flags to differentiate between current
FW in kernel that supports both ldpm and edpm.
Since edpm is not yet supported for iWARP we add different flags
for iWARP + RoCE.
We also fix bad practice of defining sizes in rdma-core and pass
initialization to kernel, for forward compatibility.

The capability flags are added for backward-forward compatibility
between kernel and rdma-core for qedr.
Before this change there was a field called dpm_enabled which could
hold either 0 or 1 value, this indicated whether RoCE edpm was
enabled or not. We modified this field to be dpm_flags, and bit 1
still holds the same meaning of RoCE edpm being enabled or not.

Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
---
rdma-core changes in pr #622 https://github.com/linux-rdma/rdma-core/pull/622
Changes from V1:
	Add better description in commit message of how
backward-compatibility is maintained
---
 drivers/infiniband/hw/qedr/verbs.c | 13 ++++++++++++-
 include/uapi/rdma/qedr-abi.h       | 18 ++++++++++++++++--
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/drivers/infiniband/hw/qedr/verbs.c b/drivers/infiniband/hw/qedr/verbs.c
index 8096b8fcab4e..54cce8969594 100644
--- a/drivers/infiniband/hw/qedr/verbs.c
+++ b/drivers/infiniband/hw/qedr/verbs.c
@@ -312,7 +312,18 @@ int qedr_alloc_ucontext(struct ib_ucontext *uctx, struct ib_udata *udata)
 	}
 	ctx->db_mmap_entry = &entry->rdma_entry;
 
-	uresp.dpm_enabled = dev->user_dpm_enabled;
+	if (!dev->user_dpm_enabled)
+		uresp.dpm_flags = 0;
+	else if (rdma_protocol_iwarp(&dev->ibdev, 1))
+		uresp.dpm_flags = QEDR_DPM_TYPE_IWARP_LEGACY;
+	else
+		uresp.dpm_flags = QEDR_DPM_TYPE_ROCE_ENHANCED |
+				  QEDR_DPM_TYPE_ROCE_LEGACY;
+
+	uresp.dpm_flags |= QEDR_DPM_SIZES_SET;
+	uresp.ldpm_limit_size = QEDR_LDPM_MAX_SIZE;
+	uresp.edpm_trans_size = QEDR_EDPM_TRANS_SIZE;
+
 	uresp.wids_enabled = 1;
 	uresp.wid_count = oparams.wid_count;
 	uresp.db_pa = rdma_user_mmap_get_offset(ctx->db_mmap_entry);
diff --git a/include/uapi/rdma/qedr-abi.h b/include/uapi/rdma/qedr-abi.h
index c022ee26089b..a0b83c9d4498 100644
--- a/include/uapi/rdma/qedr-abi.h
+++ b/include/uapi/rdma/qedr-abi.h
@@ -48,6 +48,18 @@ struct qedr_alloc_ucontext_req {
 	__u32 reserved;
 };
 
+#define QEDR_LDPM_MAX_SIZE	(8192)
+#define QEDR_EDPM_TRANS_SIZE	(64)
+
+enum qedr_rdma_dpm_type {
+	QEDR_DPM_TYPE_NONE		= 0,
+	QEDR_DPM_TYPE_ROCE_ENHANCED	= 1 << 0,
+	QEDR_DPM_TYPE_ROCE_LEGACY	= 1 << 1,
+	QEDR_DPM_TYPE_IWARP_LEGACY	= 1 << 2,
+	QEDR_DPM_TYPE_RESERVED		= 1 << 3,
+	QEDR_DPM_SIZES_SET		= 1 << 4,
+};
+
 struct qedr_alloc_ucontext_resp {
 	__aligned_u64 db_pa;
 	__u32 db_size;
@@ -59,10 +71,12 @@ struct qedr_alloc_ucontext_resp {
 	__u32 sges_per_recv_wr;
 	__u32 sges_per_srq_wr;
 	__u32 max_cqes;
-	__u8 dpm_enabled;
+	__u8 dpm_flags;
 	__u8 wids_enabled;
 	__u16 wid_count;
-	__u32 reserved;
+	__u16 ldpm_limit_size;
+	__u8 edpm_trans_size;
+	__u8 reserved;
 };
 
 struct qedr_alloc_pd_ureq {
-- 
2.14.5

Re: [PATCH v2 rdma-next] RDMA/qedr: Add kernel capability flags for dpm enabled mode

[Jason Gunthorpe]

On Thu, Nov 21, 2019 at 01:29:57PM +0200, Michal Kalderon wrote:
> HW/FW support two types of latency enhancement features.
> Until now user-space implemented only edpm (enhanced dpm).
> We add kernel capability flags to differentiate between current
> FW in kernel that supports both ldpm and edpm.
> Since edpm is not yet supported for iWARP we add different flags
> for iWARP + RoCE.
> We also fix bad practice of defining sizes in rdma-core and pass
> initialization to kernel, for forward compatibility.
> 
> The capability flags are added for backward-forward compatibility
> between kernel and rdma-core for qedr.
> Before this change there was a field called dpm_enabled which could
> hold either 0 or 1 value, this indicated whether RoCE edpm was
> enabled or not. We modified this field to be dpm_flags, and bit 1
> still holds the same meaning of RoCE edpm being enabled or not.
> 
> Signed-off-by: Michal Kalderon <michal.kalderon@marvell.com>
> ---
> rdma-core changes in pr #622 https://github.com/linux-rdma/rdma-core/pull/622
> Changes from V1:
> 	Add better description in commit message of how
> backward-compatibility is maintained
> ---
>  drivers/infiniband/hw/qedr/verbs.c | 13 ++++++++++++-
>  include/uapi/rdma/qedr-abi.h       | 18 ++++++++++++++++--
>  2 files changed, 28 insertions(+), 3 deletions(-)

Applied to for-next, thanks

Jason