system/fidl/ddk/protocols/libs/phys-iter.fidl

// Copyright 2018 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

library ddk.phys_iter;

using zx;

/// Specifies the buffer to iterate over.
[repr="C"]
struct PhysIterBuffer {
    /// List of physical addresses backing the buffer starting at vmo_offset.
    zx.paddr? phys;
    /// Number of entries in phys list.
    uint64 phys_count;
    /// Length of the buffer starting at vmo_offset.
    usize length;
    /// Offset into first page to start iterating on.
    uint64 vmo_offset;
};

/// Used to iterate over contiguous buffer ranges in the physical address space.
[repr="C"]
struct PhysIter {
    PhysIterBuffer buf;

    /// Current offset in the txn (relative to buffer vmo_offset)
    zx.off     offset;
    /// Max length to be returned by phys_iter_next()
    usize      max_length;
    /// index of page in buf->phys that contains offset
    uint64     page;
    /// last valid page index in buf->phys
    uint64     last_page;
};