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- /*
- * Copyright (c) 2020, Liav A. <liavalb@hotmail.co.il>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
- #include <AK/Memory.h>
- #include <AK/StringView.h>
- #include <Kernel/Debug.h>
- #include <Kernel/FileSystem/FileDescription.h>
- #include <Kernel/Storage/StorageDevice.h>
- #include <Kernel/Storage/StorageManagement.h>
- namespace Kernel {
- StorageDevice::StorageDevice(const StorageController& controller, size_t sector_size, u64 max_addressable_block)
- : BlockDevice(StorageManagement::major_number(), StorageManagement::minor_number(), sector_size)
- , m_storage_controller(controller)
- , m_max_addressable_block(max_addressable_block)
- {
- }
- StorageDevice::StorageDevice(const StorageController& controller, int major, int minor, size_t sector_size, u64 max_addressable_block)
- : BlockDevice(major, minor, sector_size)
- , m_storage_controller(controller)
- , m_max_addressable_block(max_addressable_block)
- {
- }
- const char* StorageDevice::class_name() const
- {
- return "StorageDevice";
- }
- NonnullRefPtr<StorageController> StorageDevice::controller() const
- {
- return m_storage_controller;
- }
- KResultOr<size_t> StorageDevice::read(FileDescription&, u64 offset, UserOrKernelBuffer& outbuf, size_t len)
- {
- unsigned index = offset / block_size();
- u16 whole_blocks = len / block_size();
- size_t remaining = len % block_size();
- unsigned blocks_per_page = PAGE_SIZE / block_size();
- // PATAChannel will chuck a wobbly if we try to read more than PAGE_SIZE
- // at a time, because it uses a single page for its DMA buffer.
- if (whole_blocks >= blocks_per_page) {
- whole_blocks = blocks_per_page;
- remaining = 0;
- }
- dbgln_if(STORAGE_DEVICE_DEBUG, "StorageDevice::read() index={}, whole_blocks={}, remaining={}", index, whole_blocks, remaining);
- if (whole_blocks > 0) {
- auto read_request = make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Read, index, whole_blocks, outbuf, whole_blocks * block_size());
- auto result = read_request->wait();
- if (result.wait_result().was_interrupted())
- return EINTR;
- switch (result.request_result()) {
- case AsyncDeviceRequest::Failure:
- case AsyncDeviceRequest::Cancelled:
- return EIO;
- case AsyncDeviceRequest::MemoryFault:
- return EFAULT;
- default:
- break;
- }
- }
- off_t pos = whole_blocks * block_size();
- if (remaining > 0) {
- auto data = ByteBuffer::create_uninitialized(block_size());
- auto data_buffer = UserOrKernelBuffer::for_kernel_buffer(data.data());
- auto read_request = make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Read, index + whole_blocks, 1, data_buffer, block_size());
- auto result = read_request->wait();
- if (result.wait_result().was_interrupted())
- return EINTR;
- switch (result.request_result()) {
- case AsyncDeviceRequest::Failure:
- return pos;
- case AsyncDeviceRequest::Cancelled:
- return EIO;
- case AsyncDeviceRequest::MemoryFault:
- // This should never happen, we're writing to a kernel buffer!
- VERIFY_NOT_REACHED();
- default:
- break;
- }
- if (!outbuf.write(data.data(), pos, remaining))
- return EFAULT;
- }
- return pos + remaining;
- }
- bool StorageDevice::can_read(const FileDescription&, size_t offset) const
- {
- return offset < (max_addressable_block() * block_size());
- }
- KResultOr<size_t> StorageDevice::write(FileDescription&, u64 offset, const UserOrKernelBuffer& inbuf, size_t len)
- {
- unsigned index = offset / block_size();
- u16 whole_blocks = len / block_size();
- size_t remaining = len % block_size();
- unsigned blocks_per_page = PAGE_SIZE / block_size();
- // PATAChannel will chuck a wobbly if we try to write more than PAGE_SIZE
- // at a time, because it uses a single page for its DMA buffer.
- if (whole_blocks >= blocks_per_page) {
- whole_blocks = blocks_per_page;
- remaining = 0;
- }
- dbgln_if(STORAGE_DEVICE_DEBUG, "StorageDevice::write() index={}, whole_blocks={}, remaining={}", index, whole_blocks, remaining);
- if (whole_blocks > 0) {
- auto write_request = make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Write, index, whole_blocks, inbuf, whole_blocks * block_size());
- auto result = write_request->wait();
- if (result.wait_result().was_interrupted())
- return EINTR;
- switch (result.request_result()) {
- case AsyncDeviceRequest::Failure:
- case AsyncDeviceRequest::Cancelled:
- return EIO;
- case AsyncDeviceRequest::MemoryFault:
- return EFAULT;
- default:
- break;
- }
- }
- off_t pos = whole_blocks * block_size();
- // since we can only write in block_size() increments, if we want to do a
- // partial write, we have to read the block's content first, modify it,
- // then write the whole block back to the disk.
- if (remaining > 0) {
- auto data = ByteBuffer::create_zeroed(block_size());
- auto data_buffer = UserOrKernelBuffer::for_kernel_buffer(data.data());
- {
- auto read_request = make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Read, index + whole_blocks, 1, data_buffer, block_size());
- auto result = read_request->wait();
- if (result.wait_result().was_interrupted())
- return EINTR;
- switch (result.request_result()) {
- case AsyncDeviceRequest::Failure:
- return pos;
- case AsyncDeviceRequest::Cancelled:
- return EIO;
- case AsyncDeviceRequest::MemoryFault:
- // This should never happen, we're writing to a kernel buffer!
- VERIFY_NOT_REACHED();
- default:
- break;
- }
- }
- if (!inbuf.read(data.data(), pos, remaining))
- return EFAULT;
- {
- auto write_request = make_request<AsyncBlockDeviceRequest>(AsyncBlockDeviceRequest::Write, index + whole_blocks, 1, data_buffer, block_size());
- auto result = write_request->wait();
- if (result.wait_result().was_interrupted())
- return EINTR;
- switch (result.request_result()) {
- case AsyncDeviceRequest::Failure:
- return pos;
- case AsyncDeviceRequest::Cancelled:
- return EIO;
- case AsyncDeviceRequest::MemoryFault:
- // This should never happen, we're writing to a kernel buffer!
- VERIFY_NOT_REACHED();
- default:
- break;
- }
- }
- }
- return pos + remaining;
- }
- bool StorageDevice::can_write(const FileDescription&, size_t offset) const
- {
- return offset < (max_addressable_block() * block_size());
- }
- }
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