drivers/net/mscc_eswitch/mscc_xfer.c

   1 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
   2 /*
   3  * Copyright (c) 2018 Microsemi Corporation
   4  */
   5
   6 #include <linux/io.h>
   7 #include "mscc_xfer.h"
   8
   9 #define QS_XTR_FLUSH_FLUSH              GENMASK(1, 0)
  10 #define QS_INJ_CTRL_GAP_SIZE(x)         ((x) << 21)
  11 #define QS_INJ_CTRL_EOF                 BIT(19)
  12 #define QS_INJ_CTRL_SOF                 BIT(18)
  13 #define QS_INJ_CTRL_VLD_BYTES(x)        ((x) << 16)
  14
  15 #define XTR_EOF_0     ntohl(0x80000000u)
  16 #define XTR_EOF_1     ntohl(0x80000001u)
  17 #define XTR_EOF_2     ntohl(0x80000002u)
  18 #define XTR_EOF_3     ntohl(0x80000003u)
  19 #define XTR_PRUNED    ntohl(0x80000004u)
  20 #define XTR_ABORT     ntohl(0x80000005u)
  21 #define XTR_ESCAPE    ntohl(0x80000006u)
  22 #define XTR_NOT_READY ntohl(0x80000007u)
  23
  24 #define BUF_CELL_SZ             60
  25 #define XTR_VALID_BYTES(x)      (4 - ((x) & 3))
  26
  27 int mscc_send(void __iomem *regs, const unsigned long *mscc_qs_offset,
  28               u32 *ifh, size_t ifh_len, u32 *buff, size_t buff_len)
  29 {
  30         int i, count = (buff_len + 3) / 4, last = buff_len % 4;
  31
  32         writel(QS_INJ_CTRL_GAP_SIZE(1) | QS_INJ_CTRL_SOF,
  33                regs + mscc_qs_offset[MSCC_QS_INJ_CTRL]);
  34
  35         for (i = 0; i < ifh_len; i++)
  36                 writel(ifh[i], regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
  37
  38         for (i = 0; i < count; i++)
  39                 writel(buff[i], regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
  40
  41         /* Add padding */
  42         while (i < (BUF_CELL_SZ / 4)) {
  43                 writel(0, regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
  44                 i++;
  45         }
  46
  47         /* Indicate EOF and valid bytes in last word */
  48         writel(QS_INJ_CTRL_GAP_SIZE(1) |
  49                QS_INJ_CTRL_VLD_BYTES(buff_len < BUF_CELL_SZ ? 0 : last) |
  50                QS_INJ_CTRL_EOF, regs + mscc_qs_offset[MSCC_QS_INJ_CTRL]);
  51
  52         /* Add dummy CRC */
  53         writel(0, regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
  54
  55         return 0;
  56 }
  57
  58 int mscc_recv(void __iomem *regs, const unsigned long *mscc_qs_offset,
  59               u32 *rxbuf, size_t ifh_len, bool byte_swap)
  60 {
  61         u8 grp = 0; /* Recv everything on CPU group 0 */
  62         int i, byte_cnt = 0;
  63         bool eof_flag = false, pruned_flag = false, abort_flag = false;
  64
  65         if (!(readl(regs + mscc_qs_offset[MSCC_QS_XTR_DATA_PRESENT]) &
  66               BIT(grp)))
  67                 return -EAGAIN;
  68
  69         /* skip IFH */
  70         for (i = 0; i < ifh_len; i++)
  71                 readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
  72
  73         while (!eof_flag) {
  74                 u32 val = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
  75                 u32 cmp = val;
  76
  77                 if (byte_swap)
  78                         cmp = ntohl(val);
  79
  80                 switch (cmp) {
  81                 case XTR_NOT_READY:
  82                         debug("%d NOT_READY...?\n", byte_cnt);
  83                         break;
  84                 case XTR_ABORT:
  85                         *rxbuf = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
  86                         abort_flag = true;
  87                         eof_flag = true;
  88                         debug("XTR_ABORT\n");
  89                         break;
  90                 case XTR_EOF_0:
  91                 case XTR_EOF_1:
  92                 case XTR_EOF_2:
  93                 case XTR_EOF_3:
  94                         byte_cnt += XTR_VALID_BYTES(val);
  95                         *rxbuf = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
  96                         eof_flag = true;
  97                         debug("EOF\n");
  98                         break;
  99                 case XTR_PRUNED:
 100                         /* But get the last 4 bytes as well */
 101                         eof_flag = true;
 102                         pruned_flag = true;
 103                         debug("PRUNED\n");
 104                         /* fallthrough */
 105                 case XTR_ESCAPE:
 106                         *rxbuf = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
 107                         byte_cnt += 4;
 108                         rxbuf++;
 109                         debug("ESCAPED\n");
 110                         break;
 111                 default:
 112                         *rxbuf = val;
 113                         byte_cnt += 4;
 114                         rxbuf++;
 115                 }
 116         }
 117
 118         if (abort_flag || pruned_flag || !eof_flag) {
 119                 debug("Discarded frame: abort:%d pruned:%d eof:%d\n",
 120                       abort_flag, pruned_flag, eof_flag);
 121                 return -EAGAIN;
 122         }
 123
 124         return byte_cnt;
 125 }
 126
 127 void mscc_flush(void __iomem *regs, const unsigned long *mscc_qs_offset)
 128 {
 129         /* All Queues flush */
 130         setbits_le32(regs + mscc_qs_offset[MSCC_QS_XTR_FLUSH],
 131                      QS_XTR_FLUSH_FLUSH);
 132
 133         /* Allow to drain */
 134         mdelay(1);
 135
 136         /* All Queues normal */
 137         clrbits_le32(regs + mscc_qs_offset[MSCC_QS_XTR_FLUSH],
 138                      QS_XTR_FLUSH_FLUSH);
 139 }