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Diffstat (limited to 'drivers/md/dm-vdo/memory-alloc.h')
| -rw-r--r-- | drivers/md/dm-vdo/memory-alloc.h | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/drivers/md/dm-vdo/memory-alloc.h b/drivers/md/dm-vdo/memory-alloc.h new file mode 100644 index 0000000000..0093d9f940 --- /dev/null +++ b/drivers/md/dm-vdo/memory-alloc.h @@ -0,0 +1,162 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright 2023 Red Hat + */ + +#ifndef VDO_MEMORY_ALLOC_H +#define VDO_MEMORY_ALLOC_H + +#include <linux/cache.h> +#include <linux/io.h> /* for PAGE_SIZE */ + +#include "permassert.h" +#include "thread-registry.h" + +/* Custom memory allocation function that tracks memory usage */ +int __must_check vdo_allocate_memory(size_t size, size_t align, const char *what, void *ptr); + +/* + * Allocate storage based on element counts, sizes, and alignment. + * + * This is a generalized form of our allocation use case: It allocates an array of objects, + * optionally preceded by one object of another type (i.e., a struct with trailing variable-length + * array), with the alignment indicated. + * + * Why is this inline? The sizes and alignment will always be constant, when invoked through the + * macros below, and often the count will be a compile-time constant 1 or the number of extra bytes + * will be a compile-time constant 0. So at least some of the arithmetic can usually be optimized + * away, and the run-time selection between allocation functions always can. In many cases, it'll + * boil down to just a function call with a constant size. + * + * @count: The number of objects to allocate + * @size: The size of an object + * @extra: The number of additional bytes to allocate + * @align: The required alignment + * @what: What is being allocated (for error logging) + * @ptr: A pointer to hold the allocated memory + * + * Return: VDO_SUCCESS or an error code + */ +static inline int __vdo_do_allocation(size_t count, size_t size, size_t extra, + size_t align, const char *what, void *ptr) +{ + size_t total_size = count * size + extra; + + /* Overflow check: */ + if ((size > 0) && (count > ((SIZE_MAX - extra) / size))) { + /* + * This is kind of a hack: We rely on the fact that SIZE_MAX would cover the entire + * address space (minus one byte) and thus the system can never allocate that much + * and the call will always fail. So we can report an overflow as "out of memory" + * by asking for "merely" SIZE_MAX bytes. + */ + total_size = SIZE_MAX; + } + + return vdo_allocate_memory(total_size, align, what, ptr); +} + +/* + * Allocate one or more elements of the indicated type, logging an error if the allocation fails. + * The memory will be zeroed. + * + * @COUNT: The number of objects to allocate + * @TYPE: The type of objects to allocate. This type determines the alignment of the allocation. + * @WHAT: What is being allocated (for error logging) + * @PTR: A pointer to hold the allocated memory + * + * Return: VDO_SUCCESS or an error code + */ +#define vdo_allocate(COUNT, TYPE, WHAT, PTR) \ + __vdo_do_allocation(COUNT, sizeof(TYPE), 0, __alignof__(TYPE), WHAT, PTR) + +/* + * Allocate one object of an indicated type, followed by one or more elements of a second type, + * logging an error if the allocation fails. The memory will be zeroed. + * + * @TYPE1: The type of the primary object to allocate. This type determines the alignment of the + * allocated memory. + * @COUNT: The number of objects to allocate + * @TYPE2: The type of array objects to allocate + * @WHAT: What is being allocated (for error logging) + * @PTR: A pointer to hold the allocated memory + * + * Return: VDO_SUCCESS or an error code + */ +#define vdo_allocate_extended(TYPE1, COUNT, TYPE2, WHAT, PTR) \ + __extension__({ \ + int _result; \ + TYPE1 **_ptr = (PTR); \ + BUILD_BUG_ON(__alignof__(TYPE1) < __alignof__(TYPE2)); \ + _result = __vdo_do_allocation(COUNT, \ + sizeof(TYPE2), \ + sizeof(TYPE1), \ + __alignof__(TYPE1), \ + WHAT, \ + _ptr); \ + _result; \ + }) + +/* + * Allocate memory starting on a cache line boundary, logging an error if the allocation fails. The + * memory will be zeroed. + * + * @size: The number of bytes to allocate + * @what: What is being allocated (for error logging) + * @ptr: A pointer to hold the allocated memory + * + * Return: VDO_SUCCESS or an error code + */ +static inline int __must_check vdo_allocate_cache_aligned(size_t size, const char *what, void *ptr) +{ + return vdo_allocate_memory(size, L1_CACHE_BYTES, what, ptr); +} + +/* + * Allocate one element of the indicated type immediately, failing if the required memory is not + * immediately available. + * + * @size: The number of bytes to allocate + * @what: What is being allocated (for error logging) + * + * Return: pointer to the memory, or NULL if the memory is not available. + */ +void *__must_check vdo_allocate_memory_nowait(size_t size, const char *what); + +int __must_check vdo_reallocate_memory(void *ptr, size_t old_size, size_t size, + const char *what, void *new_ptr); + +int __must_check vdo_duplicate_string(const char *string, const char *what, + char **new_string); + +/* Free memory allocated with vdo_allocate(). */ +void vdo_free(void *ptr); + +static inline void *__vdo_forget(void **ptr_ptr) +{ + void *ptr = *ptr_ptr; + + *ptr_ptr = NULL; + return ptr; +} + +/* + * Null out a pointer and return a copy to it. This macro should be used when passing a pointer to + * a function for which it is not safe to access the pointer once the function returns. + */ +#define vdo_forget(ptr) __vdo_forget((void **) &(ptr)) + +void vdo_memory_init(void); + +void vdo_memory_exit(void); + +void vdo_register_allocating_thread(struct registered_thread *new_thread, + const bool *flag_ptr); + +void vdo_unregister_allocating_thread(void); + +void vdo_get_memory_stats(u64 *bytes_used, u64 *peak_bytes_used); + +void vdo_report_memory_usage(void); + +#endif /* VDO_MEMORY_ALLOC_H */ |