[rdma-rc,v2,04/48] RDMA/cm: Add SET/GET implementations to hide IBA wire format
diff mbox series

Message ID 20191212093830.316934-5-leon@kernel.org
State Changes Requested
Delegated to: Jason Gunthorpe
Headers show
Series
  • Organize code according to IBTA layout
Related show

Commit Message

Leon Romanovsky Dec. 12, 2019, 9:37 a.m. UTC
From: Leon Romanovsky <leonro@mellanox.com>

There is no separation between RDMA-CM wire format as it is declared in
IBTA and kernel logic which implements needed support. Such situation
causes to many mistakes in conversion between big-endian (wire format)
and CPU format used by kernel. It also mixes RDMA core code with
combination of uXX and beXX variables.

The idea that all accesses to IBA definitions will go through special
GET/SET macros to ensure that no conversion mistakes are done.

Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
---
 drivers/infiniband/core/cm_msgs.h |   6 +-
 include/rdma/iba.h                | 138 ++++++++++++++++++++++++++++++
 2 files changed, 139 insertions(+), 5 deletions(-)
 create mode 100644 include/rdma/iba.h

Comments

Jason Gunthorpe Jan. 4, 2020, 2:15 a.m. UTC | #1
On Thu, Dec 12, 2019 at 11:37:46AM +0200, Leon Romanovsky wrote:

> +#define IBA_FIELD64_LOC(field_struct, byte_offset, num_bits)                   \
> +	field_struct, (byte_offset)&0xFFF8,                                    \
> +		GENMASK_ULL(63 - (((byte_offset) % 8) * 8),                    \
> +			    63 - (((byte_offset) % 8) * 8) - (num_bits - 1)),  \
> +		64

This doesn't quite work out right, the 64 bit fields are not naturally
aligned and we never extract anything other than 64 bits from them. So
as written this one:

#define CM_SIDR_REP_SERVICEID CM_FIELD64_LOC(struct cm_sidr_rep_msg, 12, 64)

Gives a compilation failure.

Should be 

#define IBA_FIELD64_LOC(field_struct, byte_offset)                             \
	field_struct, (byte_offset)&0xFFF8, GENMASK_ULL(63, 0), 64

As we rely on the get_unaligned() to safely retrieve the 64 bits.

Jason

Patch
diff mbox series

diff --git a/drivers/infiniband/core/cm_msgs.h b/drivers/infiniband/core/cm_msgs.h
index 92d7260ac913..9bc468833831 100644
--- a/drivers/infiniband/core/cm_msgs.h
+++ b/drivers/infiniband/core/cm_msgs.h
@@ -8,14 +8,10 @@ 
 #ifndef CM_MSGS_H
 #define CM_MSGS_H
 
+#include <rdma/iba.h>
 #include <rdma/ib_mad.h>
 #include <rdma/ib_cm.h>
 
-/*
- * Parameters to routines below should be in network-byte order, and values
- * are returned in network-byte order.
- */
-
 #define IB_CM_CLASS_VERSION	2 /* IB specification 1.2 */
 
 struct cm_req_msg {
diff --git a/include/rdma/iba.h b/include/rdma/iba.h
new file mode 100644
index 000000000000..a77cc89f9f3f
--- /dev/null
+++ b/include/rdma/iba.h
@@ -0,0 +1,138 @@ 
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/*
+ * Copyright (c) 2019, Mellanox Technologies inc.  All rights reserved.
+ */
+#ifndef _IBA_DEFS_H_
+#define _IBA_DEFS_H_
+
+#include <linux/kernel.h>
+#include <linux/bitfield.h>
+#include <asm/unaligned.h>
+
+static inline u32 _iba_get8(const u8 *ptr)
+{
+	return *ptr;
+}
+
+static inline void _iba_set8(u8 *ptr, u32 mask, u32 prep_value)
+{
+	*ptr = (*ptr & ~mask) | prep_value;
+}
+
+static inline u16 _iba_get16(const __be16 *ptr)
+{
+	return be16_to_cpu(*ptr);
+}
+
+static inline void _iba_set16(__be16 *ptr, u16 mask, u16 prep_value)
+{
+	*ptr = cpu_to_be16((be16_to_cpu(*ptr) & ~mask) | prep_value);
+}
+
+static inline u32 _iba_get32(const __be32 *ptr)
+{
+	return be32_to_cpu(*ptr);
+}
+
+static inline void _iba_set32(__be32 *ptr, u32 mask, u32 prep_value)
+{
+	*ptr = cpu_to_be32((be32_to_cpu(*ptr) & ~mask) | prep_value);
+}
+
+static inline u64 _iba_get64(const __be64 *ptr)
+{
+	/*
+	 * The mads are constructed so that 32 bit and smaller are naturally
+	 * aligned, everything larger has a max alignment of 4 bytes.
+	 */
+	return be64_to_cpu(get_unaligned(ptr));
+}
+
+static inline void _iba_set64(__be64 *ptr, u64 mask, u64 prep_value)
+{
+	put_unaligned(cpu_to_be64((_iba_get64(ptr) & ~mask) | prep_value), ptr);
+}
+
+#define _IBA_SET(field_struct, field_offset, field_mask, mask_width, ptr,      \
+		 value)                                                        \
+	({                                                                     \
+		field_struct *_ptr = ptr;                                      \
+		_iba_set##mask_width((void *)_ptr + (field_offset),            \
+				     field_mask,                               \
+				     FIELD_PREP(field_mask, value));           \
+	})
+#define IBA_SET(field, ptr, value) _IBA_SET(field, ptr, value)
+
+#define _IBA_SET_MEM(field_struct, field_offset, byte_size, ptr, in, bytes)    \
+	({                                                                     \
+		WARN_ON(bytes > byte_size);                                    \
+		if (in && bytes) {                                             \
+			field_struct *_ptr = ptr;                              \
+			memcpy((void *)_ptr + (field_offset), in, bytes);      \
+		}                                                              \
+	})
+#define IBA_SET_MEM(field, ptr, in, bytes) _IBA_SET_MEM(field, ptr, in, bytes)
+
+#define _IBA_GET(field_struct, field_offset, field_mask, mask_width, ptr)      \
+	({                                                                     \
+		const field_struct *_ptr = ptr;                                \
+		(u##mask_width) FIELD_GET(                                     \
+			field_mask, _iba_get##mask_width((const void *)_ptr +  \
+							 (field_offset)));     \
+	})
+#define IBA_GET(field, ptr) _IBA_GET(field, ptr)
+
+#define _IBA_GET_MEM(field_struct, field_offset, byte_size, ptr, out, bytes)   \
+	({                                                                     \
+		WARN_ON(bytes > byte_size);                                    \
+		if (out && bytes) {                                            \
+			const field_struct *_ptr = ptr;                        \
+			memcpy(out, (void *)_ptr + (field_offset), bytes);     \
+		}                                                              \
+	})
+#define IBA_GET_MEM(field, ptr, out, bytes) _IBA_GET_MEM(field, ptr, out, bytes)
+
+/*
+ * The generated list becomes the parameters to the macros, the order is:
+ *  - struct this applies to
+ *  - starting offset of the max
+ *  - GENMASK or GENMASK_ULL in CPU order
+ *  - The width of data the mask operations should work on, in bits
+ */
+
+/*
+ * Extraction using a tabular description like table 106. bit_offset is from
+ * the Byte[Bit] notation.
+ */
+#define IBA_FIELD_BLOC(field_struct, byte_offset, bit_offset, num_bits)        \
+	field_struct, byte_offset,                                             \
+		GENMASK(7 - (bit_offset), 7 - (bit_offset) - (num_bits - 1)),  \
+		8
+#define IBA_FIELD8_LOC(field_struct, byte_offset, num_bits)                    \
+	IBA_FIELD_BLOC(field_struct, byte_offset, 0, num_bits)
+
+#define IBA_FIELD16_LOC(field_struct, byte_offset, num_bits)                   \
+	field_struct, (byte_offset)&0xFFFE,                                    \
+		GENMASK(15 - (((byte_offset) % 2) * 8),                        \
+			15 - (((byte_offset) % 2) * 8) - (num_bits - 1)),      \
+		16
+
+#define IBA_FIELD32_LOC(field_struct, byte_offset, num_bits)                   \
+	field_struct, (byte_offset)&0xFFFC,                                    \
+		GENMASK(31 - (((byte_offset) % 4) * 8),                        \
+			31 - (((byte_offset) % 4) * 8) - (num_bits - 1)),      \
+		32
+
+#define IBA_FIELD64_LOC(field_struct, byte_offset, num_bits)                   \
+	field_struct, (byte_offset)&0xFFF8,                                    \
+		GENMASK_ULL(63 - (((byte_offset) % 8) * 8),                    \
+			    63 - (((byte_offset) % 8) * 8) - (num_bits - 1)),  \
+		64
+/*
+ * In IBTA spec, everything that is more than 64bits is multiple
+ * of bytes without leftover bits.
+ */
+#define IBA_FIELD_MLOC(field_struct, byte_offset, num_bits)                    \
+	field_struct, (byte_offset)&0xFFFC, (num_bits / 8)
+
+#endif /* _IBA_DEFS_H_ */