Diff: mbed-os/features/storage/blockdevice/BufferedBlockDevice.cpp

Revision:

0:8fdf9a60065b

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os/features/storage/blockdevice/BufferedBlockDevice.cpp	Wed Oct 10 00:33:53 2018 +0000
@@ -0,0 +1,285 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2018 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "BufferedBlockDevice.h"
+#include "mbed_assert.h"
+#include "mbed_critical.h"
+#include <algorithm>
+#include <string.h>
+
+static inline uint32_t align_down(bd_size_t val, bd_size_t size)
+{
+    return val / size * size;
+}
+
+BufferedBlockDevice::BufferedBlockDevice(BlockDevice *bd)
+    : _bd(bd), _bd_program_size(0), _curr_aligned_addr(0), _flushed(true), _cache(0), _init_ref_count(0), _is_initialized(false)
+{
+}
+
+BufferedBlockDevice::~BufferedBlockDevice()
+{
+    deinit();
+}
+
+int BufferedBlockDevice::init()
+{
+    uint32_t val = core_util_atomic_incr_u32(&_init_ref_count, 1);
+
+    if (val != 1) {
+        return BD_ERROR_OK;
+    }
+
+    int err = _bd->init();
+    if (err) {
+        return err;
+    }
+
+    _bd_program_size = _bd->get_program_size();
+
+    if (!_cache) {
+        _cache = new uint8_t[_bd_program_size];
+    }
+
+    _curr_aligned_addr = _bd->size();
+    _flushed = true;
+
+    _is_initialized = true;
+    return BD_ERROR_OK;
+}
+
+int BufferedBlockDevice::deinit()
+{
+    if (!_is_initialized) {
+        return BD_ERROR_OK;
+    }
+
+    uint32_t val = core_util_atomic_decr_u32(&_init_ref_count, 1);
+
+    if (val) {
+        return BD_ERROR_OK;
+    }
+
+    delete[] _cache;
+    _cache = 0;
+    _is_initialized = false;
+    return _bd->deinit();
+}
+
+int BufferedBlockDevice::flush()
+{
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
+    if (!_flushed) {
+        int ret = _bd->program(_cache, _curr_aligned_addr, _bd_program_size);
+        if (ret) {
+            return ret;
+        }
+        _flushed = true;
+    }
+    return 0;
+}
+
+int BufferedBlockDevice::sync()
+{
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
+    int ret = flush();
+    if (ret) {
+        return ret;
+    }
+    return _bd->sync();
+}
+
+int BufferedBlockDevice::read(void *b, bd_addr_t addr, bd_size_t size)
+{
+    MBED_ASSERT(_cache);
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
+    bool moved_unit = false;
+
+    bd_addr_t aligned_addr = align_down(addr, _bd_program_size);
+
+    uint8_t *buf = static_cast<uint8_t *> (b);
+
+    if (aligned_addr != _curr_aligned_addr) {
+        // Need to flush if moved to another program unit
+        flush();
+        _curr_aligned_addr = aligned_addr;
+        moved_unit = true;
+    }
+
+    while (size) {
+        _curr_aligned_addr = align_down(addr, _bd_program_size);
+        if (moved_unit) {
+            int ret = _bd->read(_cache, _curr_aligned_addr, _bd_program_size);
+            if (ret) {
+                return ret;
+            }
+        }
+        bd_addr_t offs_in_buf = addr - _curr_aligned_addr;
+        bd_size_t chunk = std::min(_bd_program_size - offs_in_buf, size);
+        memcpy(buf, _cache + offs_in_buf, chunk);
+        moved_unit = true;
+        buf += chunk;
+        addr += chunk;
+        size -= chunk;
+    }
+
+    return 0;
+}
+
+int BufferedBlockDevice::program(const void *b, bd_addr_t addr, bd_size_t size)
+{
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
+    int ret;
+    bool moved_unit = false;
+
+    bd_addr_t aligned_addr = align_down(addr, _bd_program_size);
+
+    const uint8_t *buf = static_cast <const uint8_t *> (b);
+
+    // Need to flush if moved to another program unit
+    if (aligned_addr != _curr_aligned_addr) {
+        flush();
+        _curr_aligned_addr = aligned_addr;
+        moved_unit = true;
+    }
+
+    while (size) {
+        _curr_aligned_addr = align_down(addr, _bd_program_size);
+        bd_addr_t offs_in_buf = addr - _curr_aligned_addr;
+        bd_size_t chunk = std::min(_bd_program_size - offs_in_buf, size);
+        const uint8_t *prog_buf;
+        if (chunk < _bd_program_size) {
+            // If moved a unit, and program doesn't cover entire unit, it means we don't have the entire
+            // program unit cached - need to complete it from underlying BD
+            if (moved_unit) {
+                ret = _bd->read(_cache, _curr_aligned_addr, _bd_program_size);
+                if (ret) {
+                    return ret;
+                }
+            }
+            memcpy(_cache + offs_in_buf, buf, chunk);
+            prog_buf = _cache;
+        } else {
+            // No need to copy data to our cache on each iteration. Just make sure it's updated
+            // on the last iteration, when size is not greater than program size (can't be smaller, as
+            // this is covered in the previous condition).
+            prog_buf = buf;
+            if (size == _bd_program_size) {
+                memcpy(_cache, buf, _bd_program_size);
+            }
+        }
+
+        // Don't flush on the last iteration, just on all preceding ones.
+        if (size > chunk) {
+            ret = _bd->program(prog_buf, _curr_aligned_addr, _bd_program_size);
+            if (ret) {
+                return ret;
+            }
+            _bd->sync();
+        } else {
+            _flushed = false;
+        }
+
+        moved_unit = true;
+        buf += chunk;
+        addr += chunk;
+        size -= chunk;
+    }
+
+    return 0;
+}
+
+int BufferedBlockDevice::erase(bd_addr_t addr, bd_size_t size)
+{
+    MBED_ASSERT(is_valid_erase(addr, size));
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
+    return _bd->erase(addr, size);
+}
+
+int BufferedBlockDevice::trim(bd_addr_t addr, bd_size_t size)
+{
+    MBED_ASSERT(is_valid_erase(addr, size));
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
+    if ((_curr_aligned_addr >= addr) && (_curr_aligned_addr <= addr + size)) {
+        _flushed = true;
+        _curr_aligned_addr = _bd->size();
+    }
+    return _bd->trim(addr, size);
+}
+
+bd_size_t BufferedBlockDevice::get_read_size() const
+{
+    return 1;
+}
+
+bd_size_t BufferedBlockDevice::get_program_size() const
+{
+    return 1;
+}
+
+bd_size_t BufferedBlockDevice::get_erase_size() const
+{
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
+    return _bd->get_erase_size();
+}
+
+bd_size_t BufferedBlockDevice::get_erase_size(bd_addr_t addr) const
+{
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
+    return _bd->get_erase_size(addr);
+}
+
+int BufferedBlockDevice::get_erase_value() const
+{
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
+    return _bd->get_erase_value();
+}
+
+bd_size_t BufferedBlockDevice::size() const
+{
+    if (!_is_initialized) {
+        return BD_ERROR_DEVICE_ERROR;
+    }
+
+    return _bd->size();
+}