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 <log.h>
   7 #include <linux/delay.h>
   8 #include <linux/io.h>
   9 #include "mscc_xfer.h"
  10
  11 #define QS_XTR_FLUSH_FLUSH              GENMASK(1, 0)
  12 #define QS_INJ_CTRL_GAP_SIZE(x)         ((x) << 21)
  13 #define QS_INJ_CTRL_EOF                 BIT(19)
  14 #define QS_INJ_CTRL_SOF                 BIT(18)
  15 #define QS_INJ_CTRL_VLD_BYTES(x)        ((x) << 16)
  16
  17 #define XTR_EOF_0     ntohl(0x80000000u)
  18 #define XTR_EOF_1     ntohl(0x80000001u)
  19 #define XTR_EOF_2     ntohl(0x80000002u)
  20 #define XTR_EOF_3     ntohl(0x80000003u)
  21 #define XTR_PRUNED    ntohl(0x80000004u)
  22 #define XTR_ABORT     ntohl(0x80000005u)
  23 #define XTR_ESCAPE    ntohl(0x80000006u)
  24 #define XTR_NOT_READY ntohl(0x80000007u)
  25
  26 #define BUF_CELL_SZ             60
  27 #define XTR_VALID_BYTES(x)      (4 - ((x) & 3))
  28
  29 int mscc_send(void __iomem *regs, const unsigned long *mscc_qs_offset,
  30               u32 *ifh, size_t ifh_len, u32 *buff, size_t buff_len)
  31 {
  32         int i, count = (buff_len + 3) / 4, last = buff_len % 4;
  33
  34         writel(QS_INJ_CTRL_GAP_SIZE(1) | QS_INJ_CTRL_SOF,
  35                regs + mscc_qs_offset[MSCC_QS_INJ_CTRL]);
  36
  37         for (i = 0; i < ifh_len; i++)
  38                 writel(ifh[i], regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
  39
  40         for (i = 0; i < count; i++)
  41                 writel(buff[i], regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
  42
  43         /* Add padding */
  44         while (i < (BUF_CELL_SZ / 4)) {
  45                 writel(0, regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
  46                 i++;
  47         }
  48
  49         /* Indicate EOF and valid bytes in last word */
  50         writel(QS_INJ_CTRL_GAP_SIZE(1) |
  51                QS_INJ_CTRL_VLD_BYTES(buff_len < BUF_CELL_SZ ? 0 : last) |
  52                QS_INJ_CTRL_EOF, regs + mscc_qs_offset[MSCC_QS_INJ_CTRL]);
  53
  54         /* Add dummy CRC */
  55         writel(0, regs + mscc_qs_offset[MSCC_QS_INJ_WR]);
  56
  57         return 0;
  58 }
  59
  60 int mscc_recv(void __iomem *regs, const unsigned long *mscc_qs_offset,
  61               u32 *rxbuf, size_t ifh_len, bool byte_swap)
  62 {
  63         u8 grp = 0; /* Recv everything on CPU group 0 */
  64         int i, byte_cnt = 0;
  65         bool eof_flag = false, pruned_flag = false, abort_flag = false;
  66
  67         if (!(readl(regs + mscc_qs_offset[MSCC_QS_XTR_DATA_PRESENT]) &
  68               BIT(grp)))
  69                 return -EAGAIN;
  70
  71         /* skip IFH */
  72         for (i = 0; i < ifh_len; i++)
  73                 readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
  74
  75         while (!eof_flag) {
  76                 u32 val = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
  77                 u32 cmp = val;
  78
  79                 if (byte_swap)
  80                         cmp = ntohl(val);
  81
  82                 switch (cmp) {
  83                 case XTR_NOT_READY:
  84                         debug("%d NOT_READY...?\n", byte_cnt);
  85                         break;
  86                 case XTR_ABORT:
  87                         *rxbuf = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
  88                         abort_flag = true;
  89                         eof_flag = true;
  90                         debug("XTR_ABORT\n");
  91                         break;
  92                 case XTR_EOF_0:
  93                 case XTR_EOF_1:
  94                 case XTR_EOF_2:
  95                 case XTR_EOF_3:
  96                         byte_cnt += XTR_VALID_BYTES(val);
  97                         *rxbuf = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
  98                         eof_flag = true;
  99                         debug("EOF\n");
 100                         break;
 101                 case XTR_PRUNED:
 102                         /* But get the last 4 bytes as well */
 103                         eof_flag = true;
 104                         pruned_flag = true;
 105                         debug("PRUNED\n");
 106                         /* fallthrough */
 107                 case XTR_ESCAPE:
 108                         *rxbuf = readl(regs + mscc_qs_offset[MSCC_QS_XTR_RD]);
 109                         byte_cnt += 4;
 110                         rxbuf++;
 111                         debug("ESCAPED\n");
 112                         break;
 113                 default:
 114                         *rxbuf = val;
 115                         byte_cnt += 4;
 116                         rxbuf++;
 117                 }
 118         }
 119
 120         if (abort_flag || pruned_flag || !eof_flag) {
 121                 debug("Discarded frame: abort:%d pruned:%d eof:%d\n",
 122                       abort_flag, pruned_flag, eof_flag);
 123                 return -EAGAIN;
 124         }
 125
 126         return byte_cnt;
 127 }
 128
 129 void mscc_flush(void __iomem *regs, const unsigned long *mscc_qs_offset)
 130 {
 131         /* All Queues flush */
 132         setbits_le32(regs + mscc_qs_offset[MSCC_QS_XTR_FLUSH],
 133                      QS_XTR_FLUSH_FLUSH);
 134
 135         /* Allow to drain */
 136         mdelay(1);
 137
 138         /* All Queues normal */
 139         clrbits_le32(regs + mscc_qs_offset[MSCC_QS_XTR_FLUSH],
 140                      QS_XTR_FLUSH_FLUSH);
 141 }