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