text: /* SPDX-License-Identifier: GPL-2.0+ */
  /*
   * Copyright (C) 2014 Freescale Semiconductor
   */
  
  #ifndef _FSL_QBMAN_BASE_H
  #define _FSL_QBMAN_BASE_H
  
  /* Descriptor for a QBMan instance on the SoC. On partitions/targets that do not
   * control this QBMan instance, these values may simply be place-holders. The
   * idea is simply that we be able to distinguish between them, eg. so that SWP
   * descriptors can identify which QBMan instance they belong to. */
  struct qbman_block_desc {
  	void *ccsr_reg_bar; /* CCSR register map */
  	int irq_rerr;  /* Recoverable error interrupt line */
  	int irq_nrerr; /* Non-recoverable error interrupt line */
  };
  
  /* Descriptor for a QBMan software portal, expressed in terms that make sense to
   * the user context. Ie. on MC, this information is likely to be true-physical,
   * and instantiated statically at compile-time. On GPP, this information is
   * likely to be obtained via "discovery" over a partition's "layerscape bus"
   * (ie. in response to a MC portal command), and would take into account any
   * virtualisation of the GPP user's address space and/or interrupt numbering. */
  struct qbman_swp_desc {
  	const struct qbman_block_desc *block; /* The QBMan instance */
  	void *cena_bar; /* Cache-enabled portal register map */
  	void *cinh_bar; /* Cache-inhibited portal register map */
  };
  
  /* Driver object for managing a QBMan portal */
  struct qbman_swp;
  
  /* Place-holder for FDs, we represent it via the simplest form that we need for
   * now. Different overlays may be needed to support different options, etc. (It
   * is impractical to define One True Struct, because the resulting encoding
   * routines (lots of read-modify-writes) would be worst-case performance whether
   * or not circumstances required them.)
   *
   * Note, as with all data-structures exchanged between software and hardware (be
   * they located in the portal register map or DMA'd to and from main-memory),
   * the driver ensures that the caller of the driver API sees the data-structures
   * in host-endianness. "struct qbman_fd" is no exception. The 32-bit words
   * contained within this structure are represented in host-endianness, even if
   * hardware always treats them as little-endian. As such, if any of these fields
   * are interpreted in a binary (rather than numerical) fashion by hardware
   * blocks (eg. accelerators), then the user should be careful. We illustrate
   * with an example;
   *
   * Suppose the desired behaviour of an accelerator is controlled by the "frc"
   * field of the FDs that are sent to it. Suppose also that the behaviour desired
   * by the user corresponds to an "frc" value which is expressed as the literal
   * sequence of bytes 0xfe, 0xed, 0xab, and 0xba. So "frc" should be the 32-bit
   * value in which 0xfe is the first byte and 0xba is the last byte, and as
   * hardware is little-endian, this amounts to a 32-bit "value" of 0xbaabedfe. If
   * the software is little-endian also, this can simply be achieved by setting
   * frc=0xbaabedfe. On the other hand, if software is big-endian, it should set
   * frc=0xfeedabba! The best away of avoiding trouble with this sort of thing is
   * to treat the 32-bit words as numerical values, in which the offset of a field
   * from the beginning of the first byte (as required or generated by hardware)
   * is numerically encoded by a left-shift (ie. by raising the field to a
   * corresponding power of 2).  Ie. in the current example, software could set
   * "frc" in the following way, and it would work correctly on both little-endian
   * and big-endian operation;
   *    fd.frc = (0xfe << 0) | (0xed << 8) | (0xab << 16) | (0xba << 24);
   */
  struct qbman_fd {
  	union {
  		uint32_t words[8];
  		struct qbman_fd_simple {
  			uint32_t addr_lo;
  			uint32_t addr_hi;
  			uint32_t len;
  			/* offset in the MS 16 bits, BPID in the LS 16 bits */
  			uint32_t bpid_offset;
  			uint32_t frc; /* frame context */
  			/* "err", "va", "cbmt", "asal", [...] */
  			uint32_t ctrl;
  			/* flow context */
  			uint32_t flc_lo;
  			uint32_t flc_hi;
  		} simple;
  	};
  };
  
  #endif /* !_FSL_QBMAN_BASE_H */
  