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/**************************************************************************/ |
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/* */ |
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/* Copyright (c) Microsoft Corporation. All rights reserved. */ |
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/* */ |
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/* This software is licensed under the Microsoft Software License */ |
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/* Terms for Microsoft Azure RTOS. Full text of the license can be */ |
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/* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */ |
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/* and in the root directory of this software. */ |
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/* */ |
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/**************************************************************************/ |
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/**************************************************************************/ |
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/**************************************************************************/ |
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/** */ |
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/** FileX Component */ |
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/** */ |
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/** Utility */ |
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/** */ |
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/**************************************************************************/ |
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/**************************************************************************/ |
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#define FX_SOURCE_CODE |
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/* Include necessary system files. */ |
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#include "fx_api.h" |
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#include "fx_system.h" |
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#include "fx_utility.h" |
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/**************************************************************************/ |
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/* */ |
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/* FUNCTION RELEASE */ |
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/* */ |
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/* _fx_utility_logical_sector_cache_entry_read PORTABLE C */ |
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/* 6.1.10 */ |
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/* AUTHOR */ |
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/* */ |
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/* William E. Lamie, Microsoft Corporation */ |
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/* */ |
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/* DESCRIPTION */ |
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/* */ |
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/* This function handles logical sector cache read requests for the */ |
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/* logical sector read function. If the function finds the requested */ |
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/* sector in the cache, it setup the appropriate pointers and */ |
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/* returns a FX_NULL. */ |
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/* */ |
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/* INPUT */ |
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/* */ |
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/* media_ptr Media control block pointer */ |
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/* logical_sector Logical sector number */ |
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/* previous_cache_entry Pointer to previous entry in */ |
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/* non-hashed cache */ |
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/* */ |
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/* OUTPUT */ |
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/* */ |
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/* FX_CACHED_SECTOR * Cache entry to setup */ |
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/* */ |
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/* CALLS */ |
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/* */ |
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/* None */ |
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/* */ |
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/* CALLED BY */ |
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/* */ |
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/* _fx_utility_logical_sector_read Logical sector read function */ |
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/* */ |
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/* RELEASE HISTORY */ |
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/* */ |
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/* DATE NAME DESCRIPTION */ |
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/* */ |
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/* 05-19-2020 William E. Lamie Initial Version 6.0 */ |
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/* 09-30-2020 William E. Lamie Modified comment(s), and */ |
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/* added conditional to */ |
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/* disable cache, */ |
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/* resulting in version 6.1 */ |
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/* 01-31-2022 William E. Lamie Modified comment(s), fixed */ |
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/* errors without cache, */ |
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/* resulting in version 6.1.10 */ |
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/* */ |
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/**************************************************************************/ |
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9703907 |
FX_CACHED_SECTOR *_fx_utility_logical_sector_cache_entry_read(FX_MEDIA *media_ptr, ULONG64 logical_sector, |
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FX_CACHED_SECTOR **previous_cache_entry) |
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{ |
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#ifndef FX_DISABLE_CACHE |
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FX_CACHED_SECTOR *cache_entry; |
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FX_CACHED_SECTOR temp_storage; |
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ULONG cache_size; |
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ULONG index; |
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/* Determine if the logical sector cache access should use the hash function. */ |
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✓✓ |
9703907 |
if (media_ptr -> fx_media_sector_cache_hashed) |
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{ |
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/* Calculate the area of the cache for this logical sector. */ |
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/* First compute the hashed value of this index by simply using the lower bits of |
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the sector number. */ |
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2827822 |
index = (ULONG)(logical_sector & media_ptr -> fx_media_sector_cache_hash_mask); |
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/* Set the bit indicating there is one or more valid sectors at this cache index. */ |
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2827822 |
media_ptr -> fx_media_sector_cache_hashed_sector_valid |= ((ULONG)1) << (index % 32); |
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/* Compute the actual array index by multiplying by the cache depth. */ |
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2827822 |
index = index * FX_SECTOR_CACHE_DEPTH; |
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/* Build a pointer to the cache entry. */ |
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2827822 |
cache_entry = &(media_ptr -> fx_media_sector_cache[index]); |
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/* Determine if the logical sector is in the cache - assuming the depth of the |
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sector cache is 4 entries. */ |
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✓✓✓✓
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2827822 |
if ((cache_entry -> fx_cached_sector_valid) && (cache_entry -> fx_cached_sector == logical_sector)) |
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{ |
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/* Yes, we found a match. Simply setup the pointer to this |
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buffer and return. */ |
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2657552 |
media_ptr -> fx_media_memory_buffer = cache_entry -> fx_cached_sector_memory_buffer; |
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#ifndef FX_MEDIA_STATISTICS_DISABLE |
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/* Increment the number of logical sectors cache read hits. */ |
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2657552 |
media_ptr -> fx_media_logical_sector_cache_read_hits++; |
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#endif |
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/* Success, return to caller immediately! */ |
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2657552 |
return(FX_NULL); |
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} |
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✓✓✓✓
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170270 |
else if (((cache_entry + 1) -> fx_cached_sector_valid) && ((cache_entry + 1) -> fx_cached_sector == logical_sector)) |
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{ |
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/* Yes, we found a match. Simply setup the pointer to this |
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buffer and return. */ |
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15171 |
media_ptr -> fx_media_memory_buffer = (cache_entry + 1) -> fx_cached_sector_memory_buffer; |
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#ifndef FX_MEDIA_STATISTICS_DISABLE |
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/* Increment the number of logical sectors cache read hits. */ |
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15171 |
media_ptr -> fx_media_logical_sector_cache_read_hits++; |
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#endif |
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/* Swap the first and second cache entries to keep the most recently used |
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at the top. */ |
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temp_storage.fx_cached_sector_memory_buffer = (cache_entry) -> fx_cached_sector_memory_buffer; |
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temp_storage.fx_cached_sector = (cache_entry) -> fx_cached_sector; |
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temp_storage.fx_cached_sector_buffer_dirty = (cache_entry) -> fx_cached_sector_buffer_dirty; |
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temp_storage.fx_cached_sector_valid = (cache_entry) -> fx_cached_sector_valid; |
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temp_storage.fx_cached_sector_type = (cache_entry) -> fx_cached_sector_type; |
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(cache_entry) -> fx_cached_sector_memory_buffer = (cache_entry + 1) -> fx_cached_sector_memory_buffer; |
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(cache_entry) -> fx_cached_sector = (cache_entry + 1) -> fx_cached_sector; |
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(cache_entry) -> fx_cached_sector_buffer_dirty = (cache_entry + 1) -> fx_cached_sector_buffer_dirty; |
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(cache_entry) -> fx_cached_sector_valid = (cache_entry + 1) -> fx_cached_sector_valid; |
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(cache_entry) -> fx_cached_sector_type = (cache_entry + 1) -> fx_cached_sector_type; |
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(cache_entry + 1) -> fx_cached_sector_memory_buffer = temp_storage.fx_cached_sector_memory_buffer; |
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(cache_entry + 1) -> fx_cached_sector = temp_storage.fx_cached_sector; |
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(cache_entry + 1) -> fx_cached_sector_buffer_dirty = temp_storage.fx_cached_sector_buffer_dirty; |
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(cache_entry + 1) -> fx_cached_sector_valid = temp_storage.fx_cached_sector_valid; |
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(cache_entry + 1) -> fx_cached_sector_type = temp_storage.fx_cached_sector_type; |
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/* Success, return to caller immediately! */ |
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return(FX_NULL); |
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} |
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✓✓✓✓
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155099 |
else if (((cache_entry + 2) -> fx_cached_sector_valid) && ((cache_entry + 2) -> fx_cached_sector == logical_sector)) |
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{ |
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/* Yes, we found a match. Simply setup the pointer to this |
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buffer and return. */ |
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1492 |
media_ptr -> fx_media_memory_buffer = (cache_entry + 2) -> fx_cached_sector_memory_buffer; |
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#ifndef FX_MEDIA_STATISTICS_DISABLE |
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/* Increment the number of logical sectors cache read hits. */ |
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1492 |
media_ptr -> fx_media_logical_sector_cache_read_hits++; |
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#endif |
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/* Move the third entry to the top and the first two entries down. */ |
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temp_storage.fx_cached_sector_memory_buffer = (cache_entry) -> fx_cached_sector_memory_buffer; |
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temp_storage.fx_cached_sector = (cache_entry) -> fx_cached_sector; |
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temp_storage.fx_cached_sector_buffer_dirty = (cache_entry) -> fx_cached_sector_buffer_dirty; |
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temp_storage.fx_cached_sector_valid = (cache_entry) -> fx_cached_sector_valid; |
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temp_storage.fx_cached_sector_type = (cache_entry) -> fx_cached_sector_type; |
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(cache_entry) -> fx_cached_sector_memory_buffer = (cache_entry + 2) -> fx_cached_sector_memory_buffer; |
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(cache_entry) -> fx_cached_sector = (cache_entry + 2) -> fx_cached_sector; |
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(cache_entry) -> fx_cached_sector_buffer_dirty = (cache_entry + 2) -> fx_cached_sector_buffer_dirty; |
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(cache_entry) -> fx_cached_sector_valid = (cache_entry + 2) -> fx_cached_sector_valid; |
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(cache_entry) -> fx_cached_sector_type = (cache_entry + 2) -> fx_cached_sector_type; |
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(cache_entry + 2) -> fx_cached_sector_memory_buffer = (cache_entry + 1) -> fx_cached_sector_memory_buffer; |
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(cache_entry + 2) -> fx_cached_sector = (cache_entry + 1) -> fx_cached_sector; |
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(cache_entry + 2) -> fx_cached_sector_buffer_dirty = (cache_entry + 1) -> fx_cached_sector_buffer_dirty; |
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(cache_entry + 2) -> fx_cached_sector_valid = (cache_entry + 1) -> fx_cached_sector_valid; |
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(cache_entry + 2) -> fx_cached_sector_type = (cache_entry + 1) -> fx_cached_sector_type; |
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(cache_entry + 1) -> fx_cached_sector_memory_buffer = temp_storage.fx_cached_sector_memory_buffer; |
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(cache_entry + 1) -> fx_cached_sector = temp_storage.fx_cached_sector; |
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(cache_entry + 1) -> fx_cached_sector_buffer_dirty = temp_storage.fx_cached_sector_buffer_dirty; |
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(cache_entry + 1) -> fx_cached_sector_valid = temp_storage.fx_cached_sector_valid; |
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(cache_entry + 1) -> fx_cached_sector_type = temp_storage.fx_cached_sector_type; |
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/* Success, return to caller immediately! */ |
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1492 |
return(FX_NULL); |
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} |
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✓✓✓✓
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153607 |
else if (((cache_entry + 3) -> fx_cached_sector_valid) && ((cache_entry + 3) -> fx_cached_sector == logical_sector)) |
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{ |
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/* Yes, we found a match. Simply setup the pointer to this |
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buffer and return. */ |
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media_ptr -> fx_media_memory_buffer = (cache_entry + 3) -> fx_cached_sector_memory_buffer; |
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#ifndef FX_MEDIA_STATISTICS_DISABLE |
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/* Increment the number of logical sectors cache read hits. */ |
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1299 |
media_ptr -> fx_media_logical_sector_cache_read_hits++; |
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#endif |
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/* Move the last entry to the top and the first three entries down. */ |
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temp_storage.fx_cached_sector_memory_buffer = (cache_entry) -> fx_cached_sector_memory_buffer; |
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temp_storage.fx_cached_sector = (cache_entry) -> fx_cached_sector; |
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temp_storage.fx_cached_sector_buffer_dirty = (cache_entry) -> fx_cached_sector_buffer_dirty; |
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temp_storage.fx_cached_sector_valid = (cache_entry) -> fx_cached_sector_valid; |
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temp_storage.fx_cached_sector_type = (cache_entry) -> fx_cached_sector_type; |
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(cache_entry) -> fx_cached_sector_memory_buffer = (cache_entry + 3) -> fx_cached_sector_memory_buffer; |
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(cache_entry) -> fx_cached_sector = (cache_entry + 3) -> fx_cached_sector; |
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(cache_entry) -> fx_cached_sector_buffer_dirty = (cache_entry + 3) -> fx_cached_sector_buffer_dirty; |
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(cache_entry) -> fx_cached_sector_valid = (cache_entry + 3) -> fx_cached_sector_valid; |
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(cache_entry) -> fx_cached_sector_type = (cache_entry + 3) -> fx_cached_sector_type; |
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(cache_entry + 3) -> fx_cached_sector_memory_buffer = (cache_entry + 2) -> fx_cached_sector_memory_buffer; |
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(cache_entry + 3) -> fx_cached_sector = (cache_entry + 2) -> fx_cached_sector; |
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(cache_entry + 3) -> fx_cached_sector_buffer_dirty = (cache_entry + 2) -> fx_cached_sector_buffer_dirty; |
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(cache_entry + 3) -> fx_cached_sector_valid = (cache_entry + 2) -> fx_cached_sector_valid; |
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(cache_entry + 3) -> fx_cached_sector_type = (cache_entry + 2) -> fx_cached_sector_type; |
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(cache_entry + 2) -> fx_cached_sector_memory_buffer = (cache_entry + 1) -> fx_cached_sector_memory_buffer; |
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(cache_entry + 2) -> fx_cached_sector = (cache_entry + 1) -> fx_cached_sector; |
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(cache_entry + 2) -> fx_cached_sector_buffer_dirty = (cache_entry + 1) -> fx_cached_sector_buffer_dirty; |
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(cache_entry + 2) -> fx_cached_sector_valid = (cache_entry + 1) -> fx_cached_sector_valid; |
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(cache_entry + 2) -> fx_cached_sector_type = (cache_entry + 1) -> fx_cached_sector_type; |
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(cache_entry + 1) -> fx_cached_sector_memory_buffer = temp_storage.fx_cached_sector_memory_buffer; |
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(cache_entry + 1) -> fx_cached_sector = temp_storage.fx_cached_sector; |
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(cache_entry + 1) -> fx_cached_sector_buffer_dirty = temp_storage.fx_cached_sector_buffer_dirty; |
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(cache_entry + 1) -> fx_cached_sector_valid = temp_storage.fx_cached_sector_valid; |
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(cache_entry + 1) -> fx_cached_sector_type = temp_storage.fx_cached_sector_type; |
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/* Success, return to caller immediately! */ |
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1299 |
return(FX_NULL); |
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} |
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/* At this point we have a cache miss. We need to move all of the sectors down one slot, swapping |
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the 4th entry with the first. */ |
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152308 |
temp_storage.fx_cached_sector_memory_buffer = (cache_entry + 3) -> fx_cached_sector_memory_buffer; |
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152308 |
temp_storage.fx_cached_sector = (cache_entry + 3) -> fx_cached_sector; |
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152308 |
temp_storage.fx_cached_sector_buffer_dirty = (cache_entry + 3) -> fx_cached_sector_buffer_dirty; |
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152308 |
temp_storage.fx_cached_sector_valid = (cache_entry + 3) -> fx_cached_sector_valid; |
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152308 |
temp_storage.fx_cached_sector_type = (cache_entry + 3) -> fx_cached_sector_type; |
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152308 |
(cache_entry + 3) -> fx_cached_sector_memory_buffer = (cache_entry + 2) -> fx_cached_sector_memory_buffer; |
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152308 |
(cache_entry + 3) -> fx_cached_sector = (cache_entry + 2) -> fx_cached_sector; |
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152308 |
(cache_entry + 3) -> fx_cached_sector_buffer_dirty = (cache_entry + 2) -> fx_cached_sector_buffer_dirty; |
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152308 |
(cache_entry + 3) -> fx_cached_sector_valid = (cache_entry + 2) -> fx_cached_sector_valid; |
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152308 |
(cache_entry + 3) -> fx_cached_sector_type = (cache_entry + 2) -> fx_cached_sector_type; |
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152308 |
(cache_entry + 2) -> fx_cached_sector_memory_buffer = (cache_entry + 1) -> fx_cached_sector_memory_buffer; |
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152308 |
(cache_entry + 2) -> fx_cached_sector = (cache_entry + 1) -> fx_cached_sector; |
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152308 |
(cache_entry + 2) -> fx_cached_sector_buffer_dirty = (cache_entry + 1) -> fx_cached_sector_buffer_dirty; |
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152308 |
(cache_entry + 2) -> fx_cached_sector_valid = (cache_entry + 1) -> fx_cached_sector_valid; |
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152308 |
(cache_entry + 2) -> fx_cached_sector_type = (cache_entry + 1) -> fx_cached_sector_type; |
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152308 |
(cache_entry + 1) -> fx_cached_sector_memory_buffer = (cache_entry) -> fx_cached_sector_memory_buffer; |
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152308 |
(cache_entry + 1) -> fx_cached_sector = (cache_entry) -> fx_cached_sector; |
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152308 |
(cache_entry + 1) -> fx_cached_sector_buffer_dirty = (cache_entry) -> fx_cached_sector_buffer_dirty; |
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152308 |
(cache_entry + 1) -> fx_cached_sector_valid = (cache_entry) -> fx_cached_sector_valid; |
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152308 |
(cache_entry + 1) -> fx_cached_sector_type = (cache_entry) -> fx_cached_sector_type; |
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152308 |
(cache_entry) -> fx_cached_sector_memory_buffer = temp_storage.fx_cached_sector_memory_buffer; |
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152308 |
(cache_entry) -> fx_cached_sector = temp_storage.fx_cached_sector; |
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152308 |
(cache_entry) -> fx_cached_sector_buffer_dirty = temp_storage.fx_cached_sector_buffer_dirty; |
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152308 |
(cache_entry) -> fx_cached_sector_valid = temp_storage.fx_cached_sector_valid; |
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152308 |
(cache_entry) -> fx_cached_sector_type = temp_storage.fx_cached_sector_type; |
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287 |
|
|
/* Set the previous pointer to NULL to avoid the linked list update below. */ |
288 |
|
152308 |
*previous_cache_entry = FX_NULL; |
289 |
|
|
} |
290 |
|
|
else |
291 |
|
|
{ |
292 |
|
|
|
293 |
|
|
/* Search for an entry in the cache that matches this request. */ |
294 |
|
6876085 |
cache_size = media_ptr -> fx_media_sector_cache_size; |
295 |
|
6876085 |
cache_entry = media_ptr -> fx_media_sector_cache_list_ptr; |
296 |
|
6876085 |
*previous_cache_entry = FX_NULL; |
297 |
|
|
|
298 |
|
|
/* Look at the cache entries until a match is found or the end of |
299 |
|
|
the cache is reached. */ |
300 |
✓✓ |
49382853 |
while (cache_size--) |
301 |
|
|
{ |
302 |
|
|
|
303 |
|
|
/* Determine if the requested sector has been found. */ |
304 |
✓✓✓✓
|
46856837 |
if ((cache_entry -> fx_cached_sector_valid) && (cache_entry -> fx_cached_sector == logical_sector)) |
305 |
|
|
{ |
306 |
|
|
|
307 |
|
|
/* Yes, we found a match. Simply setup the pointer to this |
308 |
|
|
buffer and return. */ |
309 |
|
4350069 |
media_ptr -> fx_media_memory_buffer = cache_entry -> fx_cached_sector_memory_buffer; |
310 |
|
|
|
311 |
|
|
/* Determine if we need to update the last used list. */ |
312 |
✓✓ |
4350069 |
if (*previous_cache_entry) |
313 |
|
|
{ |
314 |
|
|
|
315 |
|
|
/* Yes, the current entry is not at the front of the list |
316 |
|
|
so we need to change the order. */ |
317 |
|
|
|
318 |
|
|
/* Link the previous entry to this entry's next pointer. */ |
319 |
|
2085927 |
(*previous_cache_entry) -> fx_cached_sector_next_used = |
320 |
|
2085927 |
cache_entry -> fx_cached_sector_next_used; |
321 |
|
|
|
322 |
|
|
/* Place this entry at the head of the list. */ |
323 |
|
2085927 |
cache_entry -> fx_cached_sector_next_used = |
324 |
|
2085927 |
media_ptr -> fx_media_sector_cache_list_ptr; |
325 |
|
2085927 |
media_ptr -> fx_media_sector_cache_list_ptr = cache_entry; |
326 |
|
|
} |
327 |
|
|
|
328 |
|
|
#ifndef FX_MEDIA_STATISTICS_DISABLE |
329 |
|
|
|
330 |
|
|
/* Increment the number of logical sectors cache read hits. */ |
331 |
|
4350069 |
media_ptr -> fx_media_logical_sector_cache_read_hits++; |
332 |
|
|
#endif |
333 |
|
|
|
334 |
|
|
/* Success, return to caller immediately! */ |
335 |
|
4350069 |
return(FX_NULL); |
336 |
|
|
} |
337 |
|
|
|
338 |
|
|
/* Otherwise, we have not found the cached entry yet. */ |
339 |
|
|
|
340 |
|
|
/* If there are more entries, move to the next one. */ |
341 |
✓✓ |
42506768 |
if (cache_entry -> fx_cached_sector_next_used) |
342 |
|
|
{ |
343 |
|
|
|
344 |
|
39980752 |
*previous_cache_entry = cache_entry; |
345 |
|
39980752 |
cache_entry = cache_entry -> fx_cached_sector_next_used; |
346 |
|
|
} |
347 |
|
|
} |
348 |
|
|
} |
349 |
|
|
|
350 |
|
|
/* The requested sector is not in cache, return the last cache entry. */ |
351 |
|
2678324 |
return(cache_entry); |
352 |
|
|
#else |
353 |
|
|
FX_PARAMETER_NOT_USED(media_ptr); |
354 |
|
|
FX_PARAMETER_NOT_USED(logical_sector); |
355 |
|
|
FX_PARAMETER_NOT_USED(previous_cache_entry); |
356 |
|
|
return(FX_NULL); |
357 |
|
|
#endif /* FX_DISABLE_CACHE */ |
358 |
|
|
} |
359 |
|
|
|