From 127525c772f82a214a13899a344c5fa24f4f10a8 Mon Sep 17 00:00:00 2001 From: Aaron Durbin Date: Thu, 26 Mar 2015 12:29:12 -0500 Subject: coreboot: add memory pool infrastructure The memory pool infrastructure provides an allocator with very simple free()ing semantics: only the most recent allocation can be freed from the pool. However, it can be reset and when not used any longer providing the entire region for future allocations. Change-Id: I5ae9ab35bb769d78bbc2866c5ae3b5ce2cdce5fa Signed-off-by: Aaron Durbin Reviewed-on: http://review.coreboot.org/9129 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer --- src/include/mem_pool.h | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++ src/lib/Makefile.inc | 5 ++++ src/lib/mem_pool.c | 51 +++++++++++++++++++++++++++++++++++ 3 files changed, 129 insertions(+) create mode 100644 src/include/mem_pool.h create mode 100644 src/lib/mem_pool.c diff --git a/src/include/mem_pool.h b/src/include/mem_pool.h new file mode 100644 index 0000000000..c57b70761e --- /dev/null +++ b/src/include/mem_pool.h @@ -0,0 +1,73 @@ +/* + * This file is part of the coreboot project. + * + * Copyright 2015 Google Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc. + */ + +#ifndef _MEM_POOL_H_ +#define _MEM_POOL_H_ + +#include +#include + +/* + * The memory pool allows one to allocate memory from a fixed size buffer + * that also allows freeing semantics for reuse. However, the current + * limitation is that the most recent allocation is the only one that + * can be freed. If one tries to free any allocation that isn't the + * most recently allocated it will result in a leak within the memory pool. + * + * The memory returned by allocations are at least 8 byte aligned. Note + * that this requires the backing buffer to start on at least an 8 byte + * alignment. + */ + +struct mem_pool { + uint8_t *buf; + size_t size; + uint8_t *last_alloc; + size_t free_offset; +}; + +#define MEM_POOL_INIT(buf_, size_) \ + { \ + .buf = (buf_), \ + .size = (size_), \ + .last_alloc = NULL, \ + .free_offset = 0, \ + } + +static inline void mem_pool_reset(struct mem_pool *mp) +{ + mp->last_alloc = NULL; + mp->free_offset = 0; +} + +/* Initialize a memory pool. */ +static inline void mem_pool_init(struct mem_pool *mp, void *buf, size_t sz) +{ + mp->buf = buf; + mp->size = sz; + mem_pool_reset(mp); +} + +/* Allocate requested size from the memory pool. NULL returned on error. */ +void *mem_pool_alloc(struct mem_pool *mp, size_t sz); + +/* Free allocation from memory pool. */ +void mem_pool_free(struct mem_pool *mp, void *alloc); + +#endif /* _MEM_POOL_H_ */ diff --git a/src/lib/Makefile.inc b/src/lib/Makefile.inc index c547c70ae4..88254b9693 100644 --- a/src/lib/Makefile.inc +++ b/src/lib/Makefile.inc @@ -29,6 +29,7 @@ bootblock-$(CONFIG_COLLECT_TIMESTAMPS) += timestamp.c bootblock-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c bootblock-y += memchr.c bootblock-y += memcmp.c +bootblock-y += mem_pool.c bootblock-y += region.c verstage-y += prog_ops.c @@ -50,6 +51,7 @@ endif verstage-$(CONFIG_GENERIC_UDELAY) += timer.c verstage-$(CONFIG_GENERIC_GPIO_LIB) += gpio.c +verstage-y += mem_pool.c romstage-y += prog_ops.c romstage-y += memchr.c @@ -134,6 +136,9 @@ ramstage-$(CONFIG_RELOCATABLE_RAMSTAGE) += cbmem_stage_cache.c romstage-$(CONFIG_RELOCATABLE_RAMSTAGE) += cbmem_stage_cache.c endif +romstage-y += mem_pool.c +ramstage-y += mem_pool.c + romstage-y += region.c ramstage-y += region.c diff --git a/src/lib/mem_pool.c b/src/lib/mem_pool.c new file mode 100644 index 0000000000..4bd0668358 --- /dev/null +++ b/src/lib/mem_pool.c @@ -0,0 +1,51 @@ +/* + * This file is part of the coreboot project. + * + * Copyright 2015 Google Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc. + */ + +#include +#include + +void *mem_pool_alloc(struct mem_pool *mp, size_t sz) +{ + void *p; + + /* Make all allocations be at least 8 byte aligned. */ + sz = ALIGN_UP(sz, 8); + + /* Determine if any space available. */ + if ((mp->size - mp->free_offset) < sz) + return NULL; + + p = &mp->buf[mp->free_offset]; + + mp->free_offset += sz; + mp->last_alloc = p; + + return p; +} + +void mem_pool_free(struct mem_pool *mp, void *p) +{ + /* Determine if p was the most recent allocation. */ + if (p == NULL || mp->last_alloc != p) + return; + + mp->free_offset = mp->last_alloc - mp->buf; + /* No way to track allocation before this one. */ + mp->last_alloc = NULL; +} -- cgit v1.2.3