smc: remote memory buffers (RMBs)
* allocate data RMB memory for sending and receiving
* size depends on the maximum socket send and receive buffers
* allocated RMBs are kept during life time of the owning link group
* map the allocated RMBs to DMA
Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/smc/smc.h b/net/smc/smc.h
index 11265bd..2bf5044 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -34,6 +34,16 @@
struct smc_link_group *lgr; /* link group of connection */
u32 alert_token_local; /* unique conn. id */
u8 peer_conn_idx; /* from tcp handshake */
+ int peer_rmbe_size; /* size of peer rx buffer */
+ atomic_t peer_rmbe_space;/* remaining free bytes in peer
+ * rmbe
+ */
+
+ struct smc_buf_desc *sndbuf_desc; /* send buffer descriptor */
+ int sndbuf_size; /* sndbuf size <== sock wmem */
+ struct smc_buf_desc *rmb_desc; /* RMBE descriptor */
+ int rmbe_size; /* RMBE size <== sock rmem */
+ int rmbe_size_short;/* compressed notation */
};
struct smc_sock { /* smc sock container */
@@ -76,6 +86,41 @@
return be32_to_cpu(t);
}
+#define SMC_BUF_MIN_SIZE 16384 /* minimum size of an RMB */
+
+#define SMC_RMBE_SIZES 16 /* number of distinct sizes for an RMBE */
+/* theoretically, the RFC states that largest size would be 512K,
+ * i.e. compressed 5 and thus 6 sizes (0..5), despite
+ * struct smc_clc_msg_accept_confirm.rmbe_size being a 4 bit value (0..15)
+ */
+
+/* convert the RMB size into the compressed notation - minimum 16K.
+ * In contrast to plain ilog2, this rounds towards the next power of 2,
+ * so the socket application gets at least its desired sndbuf / rcvbuf size.
+ */
+static inline u8 smc_compress_bufsize(int size)
+{
+ u8 compressed;
+
+ if (size <= SMC_BUF_MIN_SIZE)
+ return 0;
+
+ size = (size - 1) >> 14;
+ compressed = ilog2(size) + 1;
+ if (compressed >= SMC_RMBE_SIZES)
+ compressed = SMC_RMBE_SIZES - 1;
+ return compressed;
+}
+
+/* convert the RMB size from compressed notation into integer */
+static inline int smc_uncompress_bufsize(u8 compressed)
+{
+ u32 size;
+
+ size = 0x00000001 << (((int)compressed) + 14);
+ return (int)size;
+}
+
#ifdef CONFIG_XFRM
static inline bool using_ipsec(struct smc_sock *smc)
{