IB/core: Add "type 2" memory windows support
This patch enhances the IB core support for Memory Windows (MWs).
MWs allow an application to have better/flexible control over remote
access to memory.
Two types of MWs are supported, with the second type having two flavors:
Type 1 - associated with PD only
Type 2A - associated with QPN only
Type 2B - associated with PD and QPN
Applications can allocate a MW once, and then repeatedly bind the MW
to different ranges in MRs that are associated to the same PD. Type 1
windows are bound through a verb, while type 2 windows are bound by
posting a work request.
The 32-bit memory key is composed of a 24-bit index and an 8-bit
key. The key is changed with each bind, thus allowing more control
over the peer's use of the memory key.
The changes introduced are the following:
* add memory window type enum and a corresponding parameter to ib_alloc_mw.
* type 2 memory window bind work request support.
* create a struct that contains the common part of the bind verb struct
ibv_mw_bind and the bind work request into a single struct.
* add the ib_inc_rkey helper function to advance the tag part of an rkey.
Consumer interface details:
* new device capability flags IB_DEVICE_MEM_WINDOW_TYPE_2A and
IB_DEVICE_MEM_WINDOW_TYPE_2B are added to indicate device support
for these features.
Devices can set either IB_DEVICE_MEM_WINDOW_TYPE_2A or
IB_DEVICE_MEM_WINDOW_TYPE_2B if it supports type 2A or type 2B
memory windows. It can set neither to indicate it doesn't support
type 2 windows at all.
* modify existing provides and consumers code to the new param of
ib_alloc_mw and the ib_mw_bind_info structure
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Shani Michaeli <shanim@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 46bc045..98cc4b2 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -115,6 +115,8 @@
IB_DEVICE_XRC = (1<<20),
IB_DEVICE_MEM_MGT_EXTENSIONS = (1<<21),
IB_DEVICE_BLOCK_MULTICAST_LOOPBACK = (1<<22),
+ IB_DEVICE_MEM_WINDOW_TYPE_2A = (1<<23),
+ IB_DEVICE_MEM_WINDOW_TYPE_2B = (1<<24)
};
enum ib_atomic_cap {
@@ -715,6 +717,11 @@
IB_MIG_ARMED
};
+enum ib_mw_type {
+ IB_MW_TYPE_1 = 1,
+ IB_MW_TYPE_2 = 2
+};
+
struct ib_qp_attr {
enum ib_qp_state qp_state;
enum ib_qp_state cur_qp_state;
@@ -758,6 +765,7 @@
IB_WR_FAST_REG_MR,
IB_WR_MASKED_ATOMIC_CMP_AND_SWP,
IB_WR_MASKED_ATOMIC_FETCH_AND_ADD,
+ IB_WR_BIND_MW,
};
enum ib_send_flags {
@@ -780,6 +788,23 @@
unsigned int max_page_list_len;
};
+/**
+ * struct ib_mw_bind_info - Parameters for a memory window bind operation.
+ * @mr: A memory region to bind the memory window to.
+ * @addr: The address where the memory window should begin.
+ * @length: The length of the memory window, in bytes.
+ * @mw_access_flags: Access flags from enum ib_access_flags for the window.
+ *
+ * This struct contains the shared parameters for type 1 and type 2
+ * memory window bind operations.
+ */
+struct ib_mw_bind_info {
+ struct ib_mr *mr;
+ u64 addr;
+ u64 length;
+ int mw_access_flags;
+};
+
struct ib_send_wr {
struct ib_send_wr *next;
u64 wr_id;
@@ -823,6 +848,12 @@
int access_flags;
u32 rkey;
} fast_reg;
+ struct {
+ struct ib_mw *mw;
+ /* The new rkey for the memory window. */
+ u32 rkey;
+ struct ib_mw_bind_info bind_info;
+ } bind_mw;
} wr;
u32 xrc_remote_srq_num; /* XRC TGT QPs only */
};
@@ -839,7 +870,8 @@
IB_ACCESS_REMOTE_WRITE = (1<<1),
IB_ACCESS_REMOTE_READ = (1<<2),
IB_ACCESS_REMOTE_ATOMIC = (1<<3),
- IB_ACCESS_MW_BIND = (1<<4)
+ IB_ACCESS_MW_BIND = (1<<4),
+ IB_ZERO_BASED = (1<<5)
};
struct ib_phys_buf {
@@ -862,13 +894,16 @@
IB_MR_REREG_ACCESS = (1<<2)
};
+/**
+ * struct ib_mw_bind - Parameters for a type 1 memory window bind operation.
+ * @wr_id: Work request id.
+ * @send_flags: Flags from ib_send_flags enum.
+ * @bind_info: More parameters of the bind operation.
+ */
struct ib_mw_bind {
- struct ib_mr *mr;
- u64 wr_id;
- u64 addr;
- u32 length;
- int send_flags;
- int mw_access_flags;
+ u64 wr_id;
+ int send_flags;
+ struct ib_mw_bind_info bind_info;
};
struct ib_fmr_attr {
@@ -991,6 +1026,7 @@
struct ib_pd *pd;
struct ib_uobject *uobject;
u32 rkey;
+ enum ib_mw_type type;
};
struct ib_fmr {
@@ -1202,7 +1238,8 @@
int num_phys_buf,
int mr_access_flags,
u64 *iova_start);
- struct ib_mw * (*alloc_mw)(struct ib_pd *pd);
+ struct ib_mw * (*alloc_mw)(struct ib_pd *pd,
+ enum ib_mw_type type);
int (*bind_mw)(struct ib_qp *qp,
struct ib_mw *mw,
struct ib_mw_bind *mw_bind);
@@ -2019,6 +2056,8 @@
* ib_dereg_mr - Deregisters a memory region and removes it from the
* HCA translation table.
* @mr: The memory region to deregister.
+ *
+ * This function can fail, if the memory region has memory windows bound to it.
*/
int ib_dereg_mr(struct ib_mr *mr);
@@ -2071,10 +2110,22 @@
}
/**
+ * ib_inc_rkey - increments the key portion of the given rkey. Can be used
+ * for calculating a new rkey for type 2 memory windows.
+ * @rkey - the rkey to increment.
+ */
+static inline u32 ib_inc_rkey(u32 rkey)
+{
+ const u32 mask = 0x000000ff;
+ return ((rkey + 1) & mask) | (rkey & ~mask);
+}
+
+/**
* ib_alloc_mw - Allocates a memory window.
* @pd: The protection domain associated with the memory window.
+ * @type: The type of the memory window (1 or 2).
*/
-struct ib_mw *ib_alloc_mw(struct ib_pd *pd);
+struct ib_mw *ib_alloc_mw(struct ib_pd *pd, enum ib_mw_type type);
/**
* ib_bind_mw - Posts a work request to the send queue of the specified
@@ -2084,6 +2135,10 @@
* @mw: The memory window to bind.
* @mw_bind: Specifies information about the memory window, including
* its address range, remote access rights, and associated memory region.
+ *
+ * If there is no immediate error, the function will update the rkey member
+ * of the mw parameter to its new value. The bind operation can still fail
+ * asynchronously.
*/
static inline int ib_bind_mw(struct ib_qp *qp,
struct ib_mw *mw,