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/**************************************************************************/
/* */
/* Copyright (c) Microsoft Corporation. All rights reserved. */
/* */
/* This software is licensed under the Microsoft Software License */
/* Terms for Microsoft Azure RTOS. Full text of the license can be */
/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
/* and in the root directory of this software. */
/* */
/**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** FileX Component */
/** */
/** Utility */
/** */
/**************************************************************************/
/**************************************************************************/
#define FX_SOURCE_CODE
/* Include necessary system files. */
#include "fx_api.h"
#include "fx_system.h"
#include "fx_utility.h"
#ifdef FX_ENABLE_FAULT_TOLERANT
#include "fx_fault_tolerant.h"
#endif /* FX_ENABLE_FAULT_TOLERANT */
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _fx_utility_logical_sector_read PORTABLE C */
/* 6.1.6 */
/* AUTHOR */
/* */
/* William E. Lamie, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function handles logical sector read requests for all FileX */
/* components. If the logical sector is currently in the logical */
/* sector cache, the function simply sets the appropriate pointer and */
/* returns a successful status to the caller. Otherwise, physical I/O */
/* is requested through the corresponding I/O driver. */
/* */
/* Note: Conversion of the logical sector is done inside the driver. */
/* This results in a performance boost for FLASH or RAM media */
/* devices. */
/* */
/* INPUT */
/* */
/* media_ptr Media control block pointer */
/* logical_sector Logical sector number */
/* buffer_ptr Pointer of receiving buffer */
/* sectors Number of sectors to read */
/* sector_type Type of sector(s) to read */
/* */
/* OUTPUT */
/* */
/* return status */
/* */
/* CALLS */
/* */
/* _fx_utility_logical_sector_cache_entry_read */
/* Read logical sector cache */
/* _fx_utility_logical_sector_flush Flush and invalidate sectors */
/* that overlap with non-cache */
/* sector I/O. */
/* _fx_utility_memory_copy Copy cache sector */
/* _fx_fault_tolerant_read_directory_sector */
/* Read directory sector */
/* */
/* CALLED BY */
/* */
/* FileX System Functions */
/* */
/* RELEASE HISTORY */
/* */
/* DATE NAME DESCRIPTION */
/* */
/* 05-19-2020 William E. Lamie Initial Version 6.0 */
/* 09-30-2020 William E. Lamie Modified comment(s), */
/* verified memcpy usage, and */
/* added conditional to */
/* disable cache, */
/* resulting in version 6.1 */
/* 04-02-2021 Bhupendra Naphade Modified comment(s), */
/* updated check for logical */
/* sector value, */
/* resulting in version 6.1.6 */
/* */
/**************************************************************************/
UINT _fx_utility_logical_sector_read(FX_MEDIA *media_ptr, ULONG64 logical_sector,
VOID *buffer_ptr, ULONG sectors, UCHAR sector_type)
{
#ifndef FX_DISABLE_CACHE
FX_CACHED_SECTOR *cache_entry;
FX_CACHED_SECTOR *previous_cache_entry;
ULONG64 end_sector;
#endif /* FX_DISABLE_CACHE */
#ifdef FX_ENABLE_FAULT_TOLERANT
UINT status;
#endif /* FX_ENABLE_FAULT_TOLERANT */
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Determine if the request is for FAT sector. */
if (sector_type == FX_FAT_SECTOR)
{
/* Increment the number of FAT sector reads. */
media_ptr -> fx_media_fat_sector_reads++;
}
/* Increment the number of logical sectors read. */
media_ptr -> fx_media_logical_sector_reads++;
#endif
/* Extended port-specific processing macro, which is by default defined to white space. */
FX_UTILITY_LOGICAL_SECTOR_READ_EXTENSION
#ifndef FX_DISABLE_CACHE
/* Determine if the request is for the internal media buffer area. */
if ((((UCHAR *)buffer_ptr) >= media_ptr -> fx_media_memory_buffer) &&
(((UCHAR *)buffer_ptr) <= media_ptr -> fx_media_sector_cache_end))
{
/* Internal cache buffer is requested. */
/* Examine the logical sector cache. */
cache_entry = _fx_utility_logical_sector_cache_entry_read(media_ptr, logical_sector, &previous_cache_entry);
/* Was the sector found? */
if (cache_entry == FX_NULL)
{
/* Yes, the sector was found. Return success! */
return(FX_SUCCESS);
}
/* At this point, we need to read in a sector from the media. */
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Increment the number of logical sectors cache read misses. */
media_ptr -> fx_media_logical_sector_cache_read_misses++;
#endif
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_LOG_SECTOR_CACHE_MISS, media_ptr, logical_sector, media_ptr -> fx_media_logical_sector_cache_read_misses, media_ptr -> fx_media_sector_cache_size, FX_TRACE_INTERNAL_EVENTS, 0, 0)
#else
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_LOG_SECTOR_CACHE_MISS, media_ptr, logical_sector, 0, media_ptr -> fx_media_sector_cache_size, FX_TRACE_INTERNAL_EVENTS, 0, 0)
#endif
/* First, check and see if the last used entry has been
modified. */
if ((cache_entry -> fx_cached_sector_valid) &&
(cache_entry -> fx_cached_sector_buffer_dirty))
{
/* Yes, we need to flush this buffer out to the physical media
before we read in the new buffer. */
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Increment the number of driver write sector(s) requests. */
media_ptr -> fx_media_driver_write_requests++;
#endif
/* Build write request to the driver. */
media_ptr -> fx_media_driver_request = FX_DRIVER_WRITE;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
media_ptr -> fx_media_driver_buffer = cache_entry -> fx_cached_sector_memory_buffer;
#ifdef FX_DRIVER_USE_64BIT_LBA
media_ptr -> fx_media_driver_logical_sector = cache_entry -> fx_cached_sector;
#else
media_ptr -> fx_media_driver_logical_sector = (ULONG)cache_entry -> fx_cached_sector;
#endif
media_ptr -> fx_media_driver_sectors = 1;
media_ptr -> fx_media_driver_sector_type = cache_entry -> fx_cached_sector_type;
/* Determine if the sector is a data sector or a system sector. */
if (cache_entry -> fx_cached_sector_type != FX_DATA_SECTOR)
{
/* System sector is present. */
media_ptr -> fx_media_driver_system_write = FX_TRUE;
}
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_WRITE, media_ptr, cache_entry -> fx_cached_sector, 1, cache_entry -> fx_cached_sector_memory_buffer, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Invoke the driver to write the sector. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Clear the system write flag. */
media_ptr -> fx_media_driver_system_write = FX_FALSE;
/* Check for successful completion. */
if (media_ptr -> fx_media_driver_status)
{
/* Error writing a cached sector out. Return the
error status. */
return(media_ptr -> fx_media_driver_status);
}
/* Clear the buffer dirty flag since it has been flushed
out. */
cache_entry -> fx_cached_sector_buffer_dirty = FX_FALSE;
/* Decrement the number of outstanding dirty cache entries. */
media_ptr -> fx_media_sector_cache_dirty_count--;
}
/* At this point, we can go out and setup this cached sector
entry. */
/* Compare against logical sector to make sure it is valid. */
if (logical_sector >= media_ptr -> fx_media_total_sectors)
{
return(FX_SECTOR_INVALID);
}
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Increment the number of driver read sector(s) requests. */
media_ptr -> fx_media_driver_read_requests++;
#endif
/* Build Read request to the driver. */
media_ptr -> fx_media_driver_request = FX_DRIVER_READ;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
media_ptr -> fx_media_driver_buffer = cache_entry -> fx_cached_sector_memory_buffer;
#ifdef FX_DRIVER_USE_64BIT_LBA
media_ptr -> fx_media_driver_logical_sector = logical_sector;
#else
media_ptr -> fx_media_driver_logical_sector = (ULONG)logical_sector;
#endif
media_ptr -> fx_media_driver_sectors = 1;
media_ptr -> fx_media_driver_sector_type = sector_type;
/* Determine if the sector is a data sector or a system sector. */
if (sector_type == FX_DATA_SECTOR)
{
/* Data sector is present. */
media_ptr -> fx_media_driver_data_sector_read = FX_TRUE;
}
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_READ, media_ptr, logical_sector, 1, cache_entry -> fx_cached_sector_memory_buffer, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Invoke the driver to read the sector. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Clear data sector is present flag. */
media_ptr -> fx_media_driver_data_sector_read = FX_FALSE;
/* Determine if the read was successful. */
if (media_ptr -> fx_media_driver_status == FX_SUCCESS)
{
/* Remember the sector number. */
cache_entry -> fx_cached_sector = logical_sector;
/* Make the cache entry valid. */
cache_entry -> fx_cached_sector_valid = FX_TRUE;
/* Remember the sector type. */
cache_entry -> fx_cached_sector_type = sector_type;
/* Place this entry that the head of the cached sector
list. */
/* Determine if we need to update the last used list. */
if (previous_cache_entry)
{
/* Yes, the current entry is not at the front of the list
so we need to change the order. */
/* Link the previous entry to this entry's next pointer. */
previous_cache_entry -> fx_cached_sector_next_used =
cache_entry -> fx_cached_sector_next_used;
/* Place this entry at the head of the list. */
cache_entry -> fx_cached_sector_next_used =
media_ptr -> fx_media_sector_cache_list_ptr;
media_ptr -> fx_media_sector_cache_list_ptr = cache_entry;
}
#ifdef FX_ENABLE_FAULT_TOLERANT
if (media_ptr -> fx_media_fault_tolerant_enabled &&
(media_ptr -> fx_media_fault_tolerant_state & FX_FAULT_TOLERANT_STATE_STARTED) &&
(sector_type == FX_DIRECTORY_SECTOR))
{
/* Read sector from log file. */
status = _fx_fault_tolerant_read_directory_sector(media_ptr, logical_sector, cache_entry -> fx_cached_sector_memory_buffer, 1);
/* Check for successful completion. */
if (status)
{
/* Return the error status. */
return(status);
}
}
#endif /* FX_ENABLE_FAULT_TOLERANT */
}
else
{
/* Invalidate the cache entry on read errors. */
cache_entry -> fx_cached_sector_valid = FX_FALSE;
/* Put all ones in the sector value. */
cache_entry -> fx_cached_sector = (~(ULONG64)0);
}
/* Simply setup the pointer to this buffer and return. */
media_ptr -> fx_media_memory_buffer = cache_entry -> fx_cached_sector_memory_buffer;
/* Return the driver status. */
return(media_ptr -> fx_media_driver_status);
}
#else
if ((logical_sector == media_ptr -> fx_media_memory_buffer_sector) && (sectors == 1) && (buffer_ptr == media_ptr -> fx_media_memory_buffer))
{
return(FX_SUCCESS);
}
#endif
else
{
/* Direct I/O to application buffer area. */
/* Compare against logical sector to make sure it is valid. */
if ((logical_sector + sectors - 1) > (ULONG)media_ptr -> fx_media_total_sectors)
{
return(FX_SECTOR_INVALID);
}
#ifndef FX_DISABLE_CACHE
/* Attempt to fill the beginning of the buffer from cached sectors. */
while (sectors)
{
/* Determine if the sector is in the cache. */
if (_fx_utility_logical_sector_cache_entry_read(media_ptr, logical_sector, &previous_cache_entry))
{
/* Not in the cache - get out of the loop! */
break;
}
/* Yes, sector is in the cache. Copy the data from the cache to the destination buffer. */
_fx_utility_memory_copy(media_ptr -> fx_media_memory_buffer, buffer_ptr, media_ptr -> fx_media_bytes_per_sector); /* Use case of memcpy is verified. */
/* Advance the destination buffer. */
buffer_ptr = ((UCHAR *)buffer_ptr) + media_ptr -> fx_media_bytes_per_sector;
/* Advance the sector and decrement the number of sectors left. */
logical_sector++;
sectors--;
}
/* Calculate the end sector. */
end_sector = logical_sector + sectors - 1;
/* Attempt to fill the end of the buffer from the opposite direction. */
while (sectors)
{
/* Determine if the sector is in the cache. */
if (_fx_utility_logical_sector_cache_entry_read(media_ptr, end_sector, &previous_cache_entry))
{
/* Not in the cache - get out of the loop! */
break;
}
/* Yes, sector is in the cache. Copy the data from the cache to the destination buffer. */
_fx_utility_memory_copy(media_ptr -> fx_media_memory_buffer, /* Use case of memcpy is verified. */
((UCHAR *)buffer_ptr) + ((sectors - 1) * media_ptr -> fx_media_bytes_per_sector),
media_ptr -> fx_media_bytes_per_sector);
/* Move sector to previous sector and decrement the number of sectors left. */
end_sector--;
sectors--;
}
/* Determine if there are still sectors left to read. */
if (sectors == 0)
{
/* No more sectors to read - return success! */
return(FX_SUCCESS);
}
/* Flush and invalidate any entries in the cache that are in this direct I/O read request range. */
_fx_utility_logical_sector_flush(media_ptr, logical_sector, (ULONG64) sectors, FX_TRUE);
#endif /* FX_DISABLE_CACHE */
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Increment the number of driver read sector(s) requests. */
media_ptr -> fx_media_driver_read_requests++;
#endif
/* Build read request to the driver. */
media_ptr -> fx_media_driver_request = FX_DRIVER_READ;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
media_ptr -> fx_media_driver_buffer = buffer_ptr;
#ifdef FX_DRIVER_USE_64BIT_LBA
media_ptr -> fx_media_driver_logical_sector = logical_sector;
#else
media_ptr -> fx_media_driver_logical_sector = (ULONG)logical_sector;
#endif
media_ptr -> fx_media_driver_sectors = sectors;
media_ptr -> fx_media_driver_sector_type = sector_type;
/* Determine if the sector is a data sector or a system sector. */
if (sector_type == FX_DATA_SECTOR)
{
/* Data sector is present. */
media_ptr -> fx_media_driver_data_sector_read = FX_TRUE;
}
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_READ, media_ptr, logical_sector, sectors, buffer_ptr, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Invoke the driver to read the sector. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Clear data sector is present flag. */
media_ptr -> fx_media_driver_data_sector_read = FX_FALSE;
#ifdef FX_DISABLE_CACHE
if ((media_ptr -> fx_media_driver_status == FX_SUCCESS) && (sectors == 1) && (buffer_ptr == media_ptr -> fx_media_memory_buffer))
{
media_ptr -> fx_media_memory_buffer_sector = logical_sector;
return(FX_SUCCESS);
}
#endif /* FX_DISABLE_CACHE */
#ifndef FX_DISABLE_DIRECT_DATA_READ_CACHE_FILL
/* Determine if the read was successful and if number of sectors just read will
reasonably fit into the cache. */
if ((media_ptr -> fx_media_driver_status == FX_SUCCESS) && (sectors < (media_ptr -> fx_media_sector_cache_size / 4)))
{
/* Yes, read of direct sectors was successful. */
/* Copy the sectors directly read into the cache so they are available on
subsequent read requests. */
while (sectors)
{
/* Attempt to read the cache entry. */
cache_entry = _fx_utility_logical_sector_cache_entry_read(media_ptr, logical_sector, &previous_cache_entry);
/* Extended port-specific processing macro, which is by default defined to white space. */
FX_UTILITY_LOGICAL_SECTOR_READ_EXTENSION_1
/* At this point, a cache entry should always be present since we invalidated
the cache over this sector range previously. In any case, check for the error
condition. */
if (cache_entry == FX_NULL)
{
/* This case should never happen, however, if it does simply give up on updating the
cache with the sectors from the direct read. */
return(FX_SUCCESS);
}
/* Determine if the cache entry is dirty and needs to be written out before it is used. */
if ((cache_entry -> fx_cached_sector_valid) &&
(cache_entry -> fx_cached_sector_buffer_dirty))
{
/* Yes, we need to flush this buffer out to the physical media
before we read in the new buffer. */
#ifndef FX_MEDIA_STATISTICS_DISABLE
/* Increment the number of driver write sector(s) requests. */
media_ptr -> fx_media_driver_write_requests++;
#endif
/* Build write request to the driver. */
media_ptr -> fx_media_driver_request = FX_DRIVER_WRITE;
media_ptr -> fx_media_driver_status = FX_IO_ERROR;
media_ptr -> fx_media_driver_buffer = cache_entry -> fx_cached_sector_memory_buffer;
#ifdef FX_DRIVER_USE_64BIT_LBA
media_ptr -> fx_media_driver_logical_sector = cache_entry -> fx_cached_sector;
#else
media_ptr -> fx_media_driver_logical_sector = (ULONG)cache_entry -> fx_cached_sector;
#endif
media_ptr -> fx_media_driver_sectors = 1;
media_ptr -> fx_media_driver_sector_type = cache_entry -> fx_cached_sector_type;
/* Only data sectors may be dirty when FX_FAULT_TOLERANT is defined */
#ifndef FX_FAULT_TOLERANT
/* Determine if the sector is a data sector or a system sector. */
if (cache_entry -> fx_cached_sector_type != FX_DATA_SECTOR)
{
/* System sector is present. */
media_ptr -> fx_media_driver_system_write = FX_TRUE;
}
#endif /* FX_FAULT_TOLERANT */
/* If trace is enabled, insert this event into the trace buffer. */
FX_TRACE_IN_LINE_INSERT(FX_TRACE_INTERNAL_IO_DRIVER_WRITE, media_ptr, cache_entry -> fx_cached_sector, 1, cache_entry -> fx_cached_sector_memory_buffer, FX_TRACE_INTERNAL_EVENTS, 0, 0)
/* Invoke the driver to write the sector. */
(media_ptr -> fx_media_driver_entry) (media_ptr);
/* Clear the system write flag. */
media_ptr -> fx_media_driver_system_write = FX_FALSE;
/* Check for successful completion. */
if (media_ptr -> fx_media_driver_status)
{
/* Error writing a cached sector out. Return the
error status. */
return(media_ptr -> fx_media_driver_status);
}
/* Clear the buffer dirty flag since it has been flushed
out. */
cache_entry -> fx_cached_sector_buffer_dirty = FX_FALSE;
/* Decrement the number of outstanding dirty cache entries. */
media_ptr -> fx_media_sector_cache_dirty_count--;
}
/* Now setup the cache entry with information from the new sector. */
/* Remember the sector number. */
cache_entry -> fx_cached_sector = logical_sector;
/* Make the cache entry valid. */
cache_entry -> fx_cached_sector_valid = FX_TRUE;
/* Remember the sector type. */
cache_entry -> fx_cached_sector_type = sector_type;
/* Place this entry that the head of the cached sector
list. */
/* Determine if we need to update the last used list. */
if (previous_cache_entry)
{
/* Yes, the current entry is not at the front of the list
so we need to change the order. */
/* Link the previous entry to this entry's next pointer. */
previous_cache_entry -> fx_cached_sector_next_used =
cache_entry -> fx_cached_sector_next_used;
/* Place this entry at the head of the list. */
cache_entry -> fx_cached_sector_next_used =
media_ptr -> fx_media_sector_cache_list_ptr;
media_ptr -> fx_media_sector_cache_list_ptr = cache_entry;
}
/* Copy the data from the destination buffer to the cache entry. */
_fx_utility_memory_copy(buffer_ptr, /* Use case of memcpy is verified. */
cache_entry -> fx_cached_sector_memory_buffer,
media_ptr -> fx_media_bytes_per_sector);
/* Advance the destination buffer. */
buffer_ptr = ((UCHAR *)buffer_ptr) + media_ptr -> fx_media_bytes_per_sector;
/* Advance the source sector and decrement the sector count. */
logical_sector++;
sectors--;
}
}
#endif
/* Return the driver status. */
return(media_ptr -> fx_media_driver_status);
}
}
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