cxgb4: speed up on-chip memory read

Use readq() (via t4_read_reg64()) to read 64-bits at a time.
Read residual in 32-bit multiples.

Signed-off-by: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com>
Signed-off-by: Ganesh Goudar <ganeshgr@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.c b/drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.c
index f21ed53aeb44147bb9bfa3305f0fba7101d81d31..6322b8df0ed0c7dc285cfd177e85ba60e786d6b5 100644 (file)
--- a/drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/cudbg_lib.c
@@ -884,7 +884,8 @@ static int cudbg_memory_read(struct cudbg_init *pdbg_init, int win,
        u32 win_pf, memoffset, mem_aperture, mem_base;
        struct adapter *adap = pdbg_init->adap;
        u32 pos, offset, resid;
-       u32 *buf;
+       u32 *res_buf;
+       u64 *buf;
        int ret;
 
        /* Argument sanity checks ...
@@ -892,10 +893,10 @@ static int cudbg_memory_read(struct cudbg_init *pdbg_init, int win,
        if (addr & 0x3 || (uintptr_t)hbuf & 0x3)
                return -EINVAL;
 
-       buf = (u32 *)hbuf;
+       buf = (u64 *)hbuf;
 
-       /* Try to do 32-bit reads.  Residual will be handled later. */
-       resid = len & 0x3;
+       /* Try to do 64-bit reads.  Residual will be handled later. */
+       resid = len & 0x7;
        len -= resid;
 
        ret = t4_memory_rw_init(adap, win, mtype, &memoffset, &mem_base,
@@ -916,10 +917,28 @@ static int cudbg_memory_read(struct cudbg_init *pdbg_init, int win,
 
        /* Transfer data from the adapter */
        while (len > 0) {
-               *buf++ = le32_to_cpu((__force __le32)
-                                    t4_read_reg(adap, mem_base + offset));
+               *buf++ = le64_to_cpu((__force __le64)
+                                    t4_read_reg64(adap, mem_base + offset));
+               offset += sizeof(u64);
+               len -= sizeof(u64);
+
+               /* If we've reached the end of our current window aperture,
+                * move the PCI-E Memory Window on to the next.
+                */
+               if (offset == mem_aperture) {
+                       pos += mem_aperture;
+                       offset = 0;
+                       t4_memory_update_win(adap, win, pos | win_pf);
+               }
+       }
+
+       res_buf = (u32 *)buf;
+       /* Read residual in 32-bit multiples */
+       while (resid > sizeof(u32)) {
+               *res_buf++ = le32_to_cpu((__force __le32)
+                                        t4_read_reg(adap, mem_base + offset));
                offset += sizeof(u32);
-               len -= sizeof(u32);
+               resid -= sizeof(u32);
 
                /* If we've reached the end of our current window aperture,
                 * move the PCI-E Memory Window on to the next.
@@ -931,10 +950,10 @@ static int cudbg_memory_read(struct cudbg_init *pdbg_init, int win,
                }
        }
 
-       /* Transfer residual */
+       /* Transfer residual < 32-bits */
        if (resid)
                t4_memory_rw_residual(adap, resid, mem_base + offset,
-                                     (u8 *)buf, T4_MEMORY_READ);
+                                     (u8 *)res_buf, T4_MEMORY_READ);
 
        return 0;
 }