block-device.cpp

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/*
 * This file is part of the µOS++ project (https://micro-os-plus.github.io/).
 * Copyright (c) 2018-2025 Liviu Ionescu. All rights reserved.
 *
 * Permission to use, copy, modify, and/or distribute this software
 * for any purpose is hereby granted, under the terms of the MIT license.
 *
 * If a copy of the license was not distributed with this file, it can
 * be obtained from https://opensource.org/licenses/mit.
 */
 
#if defined(OS_USE_OS_APP_CONFIG_H)
#include <cmsis-plus/os-app-config.h>
#endif
 
#include <cmsis-plus/posix-io/block-device.h>
#include <cmsis-plus/posix-io/device-registry.h>
 
#include <cmsis-plus/posix/sys/ioctl.h>
 
#include <cstring>
#include <cassert>
#include <cerrno>
#include <cstdarg>
 
// ----------------------------------------------------------------------------
 
#if defined(__clang__)
#pragma clang diagnostic ignored "-Wc++98-compat"
#endif
 
// ----------------------------------------------------------------------------
 
namespace os
{
  namespace posix
  {
    // ========================================================================
 
    block_device::block_device (block_device_impl& impl, const char* name)
        : device{
            impl,
            type::block_device,
            name,
          }
    {
#if defined(OS_TRACE_POSIX_IO_BLOCK_DEVICE)
      trace::printf ("block_device::%s(\"%s\")=@%p\n", __func__, name_, this);
#endif
 
      device_registry<device>::link (this);
    }
 
    block_device::~block_device ()
    {
#if defined(OS_TRACE_POSIX_IO_BLOCK_DEVICE)
      trace::printf ("block_device::%s() @%p %s\n", __func__, this, name_);
#endif
    }
 
    // ------------------------------------------------------------------------
 
    ssize_t
    block_device::read_block (void* buf, blknum_t blknum, std::size_t nblocks)
    {
#if defined(OS_TRACE_POSIX_IO_BLOCK_DEVICE)
      trace::printf ("block_device::%s(%p, %u, %u) @%p\n", __func__, buf,
                     blknum, nblocks, this);
#endif
 
      if (blknum + nblocks > impl ().num_blocks_)
        {
          errno = EINVAL;
          return -1;
        }
 
      if (!impl ().do_is_opened ())
        {
          errno = EBADF; // Not opened.
          return -1;
        }
 
      return impl ().do_read_block (buf, blknum, nblocks);
    }
 
    ssize_t
    block_device::write_block (const void* buf, blknum_t blknum,
                               std::size_t nblocks)
    {
#if defined(OS_TRACE_POSIX_IO_BLOCK_DEVICE)
      trace::printf ("block_device::%s(%p, %u, %u) @%p\n", __func__, buf,
                     blknum, nblocks, this);
#endif
 
      if (blknum + nblocks > impl ().num_blocks_)
        {
          errno = EINVAL;
          return -1;
        }
 
      if (!impl ().do_is_opened ())
        {
          errno = EBADF; // Not opened.
          return -1;
        }
 
      return impl ().do_write_block (buf, blknum, nblocks);
    }
 
    int
    block_device::vioctl (int request, std::va_list args)
    {
#if defined(OS_TRACE_POSIX_IO_BLOCK_DEVICE)
      trace::printf ("block_device::%s(%d) @%p\n", __func__, request, this);
#endif
 
      if (!impl ().do_is_opened ())
        {
          errno = EBADF; // Not opened.
          return -1;
        }
 
      errno = 0;
 
      switch (static_cast<unsigned int> (request))
        {
        case BLKSSZGET:
          // Get logical device sector size (to be used for read/writes).
          {
            std::size_t* sz = va_arg (args, std::size_t*);
            if (sz == nullptr || impl ().block_logical_size_bytes_ != 0)
              {
                errno = EINVAL;
                return -1;
              }
 
            *sz = impl ().block_logical_size_bytes_;
            return 0;
          }
 
        case BLKPBSZGET:
          // Get physical device sector size (internally used for erase).
          {
            std::size_t* sz = va_arg (args, std::size_t*);
            if (sz == nullptr || impl ().block_physical_size_bytes_ != 0)
              {
                errno = EINVAL;
                return -1;
              }
 
            *sz = impl ().block_physical_size_bytes_;
            return 0;
          }
 
        case BLKGETSIZE64:
          // Get device size in bytes.
          {
            uint64_t* sz = va_arg (args, uint64_t*);
            if (sz == nullptr || impl ().num_blocks_ != 0)
              {
                errno = EINVAL;
                return -1;
              }
 
#pragma GCC diagnostic push
#if defined(__clang__)
#elif defined(__GNUC__)
#pragma GCC diagnostic ignored "-Wuseless-cast"
#endif
            *sz = (static_cast<uint64_t> (
                impl ().num_blocks_ * impl ().block_logical_size_bytes_));
#pragma GCC diagnostic pop
 
            return 0;
          }
 
        default:
 
          // Execute the implementation specific code.
          return impl ().do_vioctl (request, args);
        }
    }
 
    // ========================================================================
 
    block_device_impl::block_device_impl (void)
    {
#if defined(OS_TRACE_POSIX_IO_BLOCK_DEVICE)
      trace::printf ("block_device_impl::%s()=@%p\n", __func__, this);
#endif
    }
 
    block_device_impl::~block_device_impl ()
    {
#if defined(OS_TRACE_POSIX_IO_BLOCK_DEVICE)
      trace::printf ("block_device_impl::%s() @%p\n", __func__, this);
#endif
 
      block_logical_size_bytes_ = 0;
      num_blocks_ = 0;
    }
 
    // ------------------------------------------------------------------------
 
    off_t
    block_device_impl::do_lseek (off_t offset, int whence)
    {
#if defined(OS_TRACE_POSIX_IO_BLOCK_DEVICE)
      trace::printf ("block_device_impl::%s(%d, %d) @%p\n", __func__, offset,
                     whence, this);
#endif
 
      errno = 0;
      off_t tmp = offset_;
 
      switch (whence)
        {
        case SEEK_SET:
          tmp = offset;
          break;
 
        case SEEK_CUR:
          tmp += offset;
          break;
 
        case SEEK_END:
          errno = EINVAL;
          return -1;
 
        default:
          errno = EINVAL;
          return -1;
        }
 
      if (tmp < 0)
        {
          errno = EINVAL;
          return -1;
        }
      offset_ = tmp;
      return tmp;
    }
 
    // ------------------------------------------------------------------------
 
    ssize_t
    block_device_impl::do_read (void* buf, std::size_t nbyte)
    {
#if defined(OS_TRACE_POSIX_IO_BLOCK_DEVICE)
      trace::printf ("block_device_impl::%s(%p, %u) @%p\n", __func__, buf,
                     nbyte, this);
#endif
 
      if ((block_logical_size_bytes_ == 0)
          || ((nbyte % block_logical_size_bytes_) != 0)
          || ((static_cast<std::size_t> (offset_) % block_logical_size_bytes_)
              != 0))
        {
          errno = EINVAL;
          return -1;
        }
 
      std::size_t nblocks = nbyte / block_logical_size_bytes_;
      blknum_t blknum
          = static_cast<std::size_t> (offset_) / block_logical_size_bytes_;
 
      if (blknum + nblocks > num_blocks_)
        {
          errno = EINVAL;
          return -1;
        }
 
      ssize_t ret = do_read_block (buf, blknum, nblocks);
      if (ret >= 0)
        {
          ret *= static_cast<ssize_t> (block_logical_size_bytes_);
        }
      return ret;
    }
 
    ssize_t
    block_device_impl::do_write (const void* buf, std::size_t nbyte)
    {
#if defined(OS_TRACE_POSIX_IO_BLOCK_DEVICE)
      trace::printf ("block_device_impl::%s(%p, %u) @%p\n", __func__, buf,
                     nbyte, this);
#endif
 
      if ((block_logical_size_bytes_ == 0)
          || ((nbyte % block_logical_size_bytes_) != 0)
          || ((static_cast<std::size_t> (offset_) % block_logical_size_bytes_)
              != 0))
        {
          errno = EINVAL;
          return -1;
        }
 
      std::size_t nblocks = nbyte / block_logical_size_bytes_;
      blknum_t blknum
          = static_cast<std::size_t> (offset_) / block_logical_size_bytes_;
 
      if (blknum + nblocks > num_blocks_)
        {
          errno = EINVAL;
          return -1;
        }
 
      ssize_t ret = do_write_block (buf, blknum, nblocks);
      if (ret >= 0)
        {
          ret *= static_cast<ssize_t> (block_logical_size_bytes_);
        }
      return ret;
    }
 
    // ========================================================================
  } /* namespace posix */
} /* namespace os */
 
// ----------------------------------------------------------------------------