Aaron Durbin (adurbin@google.com) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/9129
-gerrit
commit 0535c431033a9b4e9237dbad136481e95a77a77d Author: Aaron Durbin adurbin@chromium.org Date: Thu Mar 26 12:29:12 2015 -0500
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 free from the pool. However, it can be reset and when not used any longer.
Change-Id: I5ae9ab35bb769d78bbc2866c5ae3b5ce2cdce5fa Signed-off-by: Aaron Durbin adurbin@chromium.org --- src/include/mem_pool.h | 73 ++++++++++++++++++++++++++++++++++++++++++++++++++ src/lib/Makefile.inc | 5 ++++ src/lib/mem_pool.c | 51 +++++++++++++++++++++++++++++++++++ 3 files changed, 129 insertions(+)
diff --git a/src/include/mem_pool.h b/src/include/mem_pool.h new file mode 100644 index 0000000..ca01fcb --- /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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef _MEM_POOL_H_ +#define _MEM_POOL_H_ + +#include <stddef.h> +#include <stdint.h> + +/* + * 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 6f9b3b0..64a2623 100644 --- a/src/lib/Makefile.inc +++ b/src/lib/Makefile.inc @@ -25,6 +25,7 @@ bootblock-$(CONFIG_COMMON_CBFS_SPI_WRAPPER) += cbfs_spi.c bootblock-$(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 @@ -36,6 +37,7 @@ verstage-$(CONFIG_CONSOLE_CBMEM) += cbmem_console.c verstage-$(CONFIG_COMMON_CBFS_SPI_WRAPPER) += cbfs_spi.c verstage-y += tlcl.c verstage-$(CONFIG_GENERIC_UDELAY) += timer.c +verstage-y += mem_pool.c
romstage-y += prog_ops.c romstage-y += memchr.c @@ -114,6 +116,9 @@ ramstage-$(RELOCATABLE_RAMSTAGE) += cbmem_stage_cache.c romstage-$(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 0000000..b3b2f5e --- /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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <mem_pool.h> +#include <stdlib.h> + +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; +}