[for-next 3/4] RDMA/ionic: allocate a PD-scoped DMA MR
From: Abhijit Gangurde
Date: Sat Nov 07 2026 - 10:49:49 EST
From: Gregor Dick <gregor.dick@xxxxxxx>
ib_get_dma_mr() returns an rkey for an identity mapping of the whole
address space, bound to the protection domain, with the requested
access. CREATE_MR carries IONIC_MRF_DMA_MR and leaves the VA, length,
and map_count at zero because firmware owns that mapping.
Signed-off-by: Gregor Dick <gregor.dick@xxxxxxx>
Signed-off-by: Abhijit Gangurde <abhijit.gangurde@xxxxxxx>
---
.../infiniband/hw/ionic/ionic_controlpath.c | 38 +++++++++++++++++--
drivers/infiniband/hw/ionic/ionic_fw.h | 16 ++++++++
drivers/infiniband/hw/ionic/ionic_ibdev.h | 1 -
drivers/infiniband/hw/ionic/ionic_lif_cfg.c | 1 +
drivers/infiniband/hw/ionic/ionic_lif_cfg.h | 1 +
5 files changed, 52 insertions(+), 5 deletions(-)
diff --git a/drivers/infiniband/hw/ionic/ionic_controlpath.c b/drivers/infiniband/hw/ionic/ionic_controlpath.c
index 8a0a1575a339..b7f878c79070 100644
--- a/drivers/infiniband/hw/ionic/ionic_controlpath.c
+++ b/drivers/infiniband/hw/ionic/ionic_controlpath.c
@@ -910,20 +910,50 @@ static int ionic_destroy_mr_cmd(struct ionic_ibdev *dev, u32 mrid)
struct ib_mr *ionic_get_dma_mr(struct ib_pd *ibpd, int access)
{
+ struct ionic_ibdev *dev = to_ionic_ibdev(ibpd->device);
struct ionic_pd *pd = to_ionic_pd(ibpd);
struct ionic_mr *mr;
+ int rc;
mr = kzalloc_obj(*mr);
if (!mr)
return ERR_PTR(-ENOMEM);
- mr->ibmr.lkey = IONIC_DMA_LKEY;
- mr->ibmr.rkey = IONIC_DMA_RKEY;
-
- if (pd)
+ if (!(dev->lif_cfg.cap & IONIC_GEN_CAP_DMA_MR)) {
+ mr->ibmr.lkey = IONIC_DMA_LKEY;
pd->flags |= IONIC_QPF_PRIVILEGED;
+ return &mr->ibmr;
+ }
+
+ rc = ionic_get_mrid(dev, &mr->mrid);
+ if (rc)
+ goto err_mrid;
+
+ mr->ibmr.lkey = mr->mrid;
+ mr->ibmr.rkey = mr->mrid;
+
+ /*
+ * Identity map of the whole address space, bound to this pd.
+ * Firmware owns that extent, so the VA, length, and map_count
+ * stay zero.
+ */
+ mr->flags = IONIC_MRF_DMA_MR | to_ionic_mr_flags(access);
+
+ rc = ionic_create_mr_cmd(dev, pd, mr, 0, 0);
+ if (rc)
+ goto err_cmd;
+
+ pd->flags |= IONIC_QPF_PRIVILEGED;
+
return &mr->ibmr;
+
+err_cmd:
+ ionic_put_mrid(dev, mr->mrid);
+err_mrid:
+ kfree(mr);
+
+ return ERR_PTR(rc);
}
struct ib_mr *ionic_reg_user_mr(struct ib_pd *ibpd, u64 start, u64 length,
diff --git a/drivers/infiniband/hw/ionic/ionic_fw.h b/drivers/infiniband/hw/ionic/ionic_fw.h
index b8e996d4b8b9..100138e4cae7 100644
--- a/drivers/infiniband/hw/ionic/ionic_fw.h
+++ b/drivers/infiniband/hw/ionic/ionic_fw.h
@@ -11,6 +11,11 @@
#define IONIC_EXP_DBELL_SZ 8
+/* ionic_lif_identity.rdma.cap bits */
+enum ionic_gen_cap_flags {
+ IONIC_GEN_CAP_DMA_MR = BIT(0),
+};
+
enum ionic_mrid_bits {
IONIC_MRID_INDEX_SHIFT = 8,
};
@@ -47,6 +52,17 @@ enum ionic_mr_flags {
IONIC_MRF_PB = BIT(7),
IONIC_MRF_ACCESS_MASK = BIT(12) - 1,
+ /*
+ * DMA_MR is an MR type selector, not an access permission. It
+ * sits in an otherwise-unused bit inside the access-mask range
+ * to_ionic_mr_flags() does not derive this bit from IB access
+ * flags. Firmware tests it before decoding access bits and takes
+ * a dedicated path.
+ *
+ * DMA_MR: identity map of the full address space, bound to a pd.
+ */
+ IONIC_MRF_DMA_MR = BIT(8),
+
/* bits that determine mr type */
IONIC_MRF_UKEY_EN = BIT(13),
IONIC_MRF_IS_MW = BIT(14),
diff --git a/drivers/infiniband/hw/ionic/ionic_ibdev.h b/drivers/infiniband/hw/ionic/ionic_ibdev.h
index 127b79cdfc45..8e7e52c9f492 100644
--- a/drivers/infiniband/hw/ionic/ionic_ibdev.h
+++ b/drivers/infiniband/hw/ionic/ionic_ibdev.h
@@ -44,7 +44,6 @@
#define IONIC_ROCE_UDP_SPORT 28272
#define IONIC_DMA_LKEY 0
-#define IONIC_DMA_RKEY IONIC_DMA_LKEY
#define IONIC_CMB_SUPPORTED \
(IONIC_CMB_ENABLE | IONIC_CMB_REQUIRE | IONIC_CMB_EXPDB | \
diff --git a/drivers/infiniband/hw/ionic/ionic_lif_cfg.c b/drivers/infiniband/hw/ionic/ionic_lif_cfg.c
index 66cee57442e7..dcf54856603d 100644
--- a/drivers/infiniband/hw/ionic/ionic_lif_cfg.c
+++ b/drivers/infiniband/hw/ionic/ionic_lif_cfg.c
@@ -95,6 +95,7 @@ void ionic_fill_lif_cfg(struct ionic_lif *lif, struct ionic_lif_cfg *cfg)
cfg->rq_expdb =
!!(lif->qtype_info[IONIC_QTYPE_RXQ].features & IONIC_QIDENT_F_EXPDB);
cfg->alloc_qid_cap = ident->rdma.alloc_qid_cap;
+ cfg->cap = le64_to_cpu(ident->rdma.cap);
}
struct net_device *ionic_lif_netdev(struct ionic_lif *lif)
diff --git a/drivers/infiniband/hw/ionic/ionic_lif_cfg.h b/drivers/infiniband/hw/ionic/ionic_lif_cfg.h
index bc14fc0921da..998785fef2f1 100644
--- a/drivers/infiniband/hw/ionic/ionic_lif_cfg.h
+++ b/drivers/infiniband/hw/ionic/ionic_lif_cfg.h
@@ -26,6 +26,7 @@ struct ionic_lif_cfg {
void *phc_state;
u64 page_size_supported;
+ u64 cap;
u32 npts_per_lif;
u32 nmrs_per_lif;
u32 nahs_per_lif;
--
2.43.0