include/fsl-mc/fsl_qbman_base.h

   1 /*
   2  * Copyright (C) 2014 Freescale Semiconductor
   3  *
   4  * SPDX-License-Identifier:     GPL-2.0+
   5  */
   6
   7 #ifndef _FSL_QBMAN_BASE_H
   8 #define _FSL_QBMAN_BASE_H
   9
  10 /* Descriptor for a QBMan instance on the SoC. On partitions/targets that do not
  11  * control this QBMan instance, these values may simply be place-holders. The
  12  * idea is simply that we be able to distinguish between them, eg. so that SWP
  13  * descriptors can identify which QBMan instance they belong to. */
  14 struct qbman_block_desc {
  15         void *ccsr_reg_bar; /* CCSR register map */
  16         int irq_rerr;  /* Recoverable error interrupt line */
  17         int irq_nrerr; /* Non-recoverable error interrupt line */
  18 };
  19
  20 /* Descriptor for a QBMan software portal, expressed in terms that make sense to
  21  * the user context. Ie. on MC, this information is likely to be true-physical,
  22  * and instantiated statically at compile-time. On GPP, this information is
  23  * likely to be obtained via "discovery" over a partition's "layerscape bus"
  24  * (ie. in response to a MC portal command), and would take into account any
  25  * virtualisation of the GPP user's address space and/or interrupt numbering. */
  26 struct qbman_swp_desc {
  27         const struct qbman_block_desc *block; /* The QBMan instance */
  28         void *cena_bar; /* Cache-enabled portal register map */
  29         void *cinh_bar; /* Cache-inhibited portal register map */
  30 };
  31
  32 /* Driver object for managing a QBMan portal */
  33 struct qbman_swp;
  34
  35 /* Place-holder for FDs, we represent it via the simplest form that we need for
  36  * now. Different overlays may be needed to support different options, etc. (It
  37  * is impractical to define One True Struct, because the resulting encoding
  38  * routines (lots of read-modify-writes) would be worst-case performance whether
  39  * or not circumstances required them.)
  40  *
  41  * Note, as with all data-structures exchanged between software and hardware (be
  42  * they located in the portal register map or DMA'd to and from main-memory),
  43  * the driver ensures that the caller of the driver API sees the data-structures
  44  * in host-endianness. "struct qbman_fd" is no exception. The 32-bit words
  45  * contained within this structure are represented in host-endianness, even if
  46  * hardware always treats them as little-endian. As such, if any of these fields
  47  * are interpreted in a binary (rather than numerical) fashion by hardware
  48  * blocks (eg. accelerators), then the user should be careful. We illustrate
  49  * with an example;
  50  *
  51  * Suppose the desired behaviour of an accelerator is controlled by the "frc"
  52  * field of the FDs that are sent to it. Suppose also that the behaviour desired
  53  * by the user corresponds to an "frc" value which is expressed as the literal
  54  * sequence of bytes 0xfe, 0xed, 0xab, and 0xba. So "frc" should be the 32-bit
  55  * value in which 0xfe is the first byte and 0xba is the last byte, and as
  56  * hardware is little-endian, this amounts to a 32-bit "value" of 0xbaabedfe. If
  57  * the software is little-endian also, this can simply be achieved by setting
  58  * frc=0xbaabedfe. On the other hand, if software is big-endian, it should set
  59  * frc=0xfeedabba! The best away of avoiding trouble with this sort of thing is
  60  * to treat the 32-bit words as numerical values, in which the offset of a field
  61  * from the beginning of the first byte (as required or generated by hardware)
  62  * is numerically encoded by a left-shift (ie. by raising the field to a
  63  * corresponding power of 2).  Ie. in the current example, software could set
  64  * "frc" in the following way, and it would work correctly on both little-endian
  65  * and big-endian operation;
  66  *    fd.frc = (0xfe << 0) | (0xed << 8) | (0xab << 16) | (0xba << 24);
  67  */
  68 struct qbman_fd {
  69         union {
  70                 uint32_t words[8];
  71                 struct qbman_fd_simple {
  72                         uint32_t addr_lo;
  73                         uint32_t addr_hi;
  74                         uint32_t len;
  75                         /* offset in the MS 16 bits, BPID in the LS 16 bits */
  76                         uint32_t bpid_offset;
  77                         uint32_t frc; /* frame context */
  78                         /* "err", "va", "cbmt", "asal", [...] */
  79                         uint32_t ctrl;
  80                         /* flow context */
  81                         uint32_t flc_lo;
  82                         uint32_t flc_hi;
  83                 } simple;
  84         };
  85 };
  86
  87 #endif /* !_FSL_QBMAN_BASE_H */