aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorAaron Durbin <adurbin@chromium.org>2015-03-26 12:29:12 -0500
committerAaron Durbin <adurbin@chromium.org>2015-05-14 17:27:09 +0200
commit127525c772f82a214a13899a344c5fa24f4f10a8 (patch)
treedf8fc570425529dc9f9763bef2b1ca30efaa7a38
parent5d5f4b3c84677213d669d2218bc9a21e4177dcf7 (diff)
downloadcoreboot-127525c772f82a214a13899a344c5fa24f4f10a8.tar.gz
coreboot-127525c772f82a214a13899a344c5fa24f4f10a8.tar.xz
coreboot-127525c772f82a214a13899a344c5fa24f4f10a8.zip
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 <adurbin@chromium.org> Reviewed-on: http://review.coreboot.org/9129 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
-rw-r--r--src/include/mem_pool.h73
-rw-r--r--src/lib/Makefile.inc5
-rw-r--r--src/lib/mem_pool.c51
3 files changed, 129 insertions, 0 deletions
diff --git a/src/include/mem_pool.h b/src/include/mem_pool.h
new file mode 100644
index 000000000..c57b70761
--- /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 <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 c547c70ae..88254b969 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 000000000..4bd066835
--- /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 <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;
+}