lib: add memrange infrastructure
The memrange infrastructure allows for keeping track of the
machine's physical address space. Each memory_range entry in
a memory_ranges structure can be tagged with an arbitrary value.
It supports merging and deleting ranges as well as filling in
holes in the address space with a particular tag.
The memrange infrastructure will serve as a shared implementation
for address tracking by the MTRR and coreboot mem table code.
Change-Id: Id5bea9d2a419114fca55c59af0fdca063551110e
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2888
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/lib/memrange.c b/src/lib/memrange.c
new file mode 100644
index 0000000..c376d52
--- /dev/null
+++ b/src/lib/memrange.c
@@ -0,0 +1,323 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 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 <stdlib.h>
+#include <console/console.h>
+#include <memrange.h>
+
+/* Coreboot doesn't have a free() function. Therefore, keep a cache of
+ * free'd entries. */
+static struct range_entry *free_list;
+
+static inline void range_entry_link(struct range_entry **prev_ptr,
+ struct range_entry *r)
+{
+ r->next = *prev_ptr;
+ *prev_ptr = r;
+}
+
+static inline void range_entry_unlink(struct range_entry **prev_ptr,
+ struct range_entry *r)
+{
+ *prev_ptr = r->next;
+ r->next = NULL;
+}
+
+static inline void range_entry_unlink_and_free(struct range_entry **prev_ptr,
+ struct range_entry *r)
+{
+ range_entry_unlink(prev_ptr, r);
+ range_entry_link(&free_list, r);
+}
+
+static struct range_entry *alloc_range(void)
+{
+ if (free_list != NULL) {
+ struct range_entry *r;
+
+ r = free_list;
+ range_entry_unlink(&free_list, r);
+ return r;
+ }
+ return malloc(sizeof(struct range_entry));
+}
+
+static inline struct range_entry *
+range_list_add(struct range_entry **prev_ptr, resource_t begin, resource_t end,
+ unsigned long tag)
+{
+ struct range_entry *new_entry;
+
+ new_entry = alloc_range();
+ if (new_entry == NULL) {
+ printk(BIOS_ERR, "Could not allocate range_entry!\n");
+ return NULL;
+ }
+ new_entry->begin = begin;
+ new_entry->end = end;
+ new_entry->tag = tag;
+ range_entry_link(prev_ptr, new_entry);
+
+ return new_entry;
+}
+
+static void merge_neighbor_entries(struct memranges *ranges)
+{
+ struct range_entry *cur;
+ struct range_entry *prev;
+
+ prev = NULL;
+ /* Merge all neighbors and delete/free the leftover entry. */
+ for (cur = ranges->entries; cur != NULL; cur = cur->next) {
+ /* First entry. Just set prev. */
+ if (prev == NULL) {
+ prev = cur;
+ continue;
+ }
+
+ /* If the previous entry merges with the current update the
+ * previous entry to cover full range and delete current from
+ * the list. */
+ if (prev->end + 1 >= cur->begin && prev->tag == cur->tag) {
+ prev->end = cur->end;
+ range_entry_unlink_and_free(&prev->next, cur);
+ /* Set cur to prev so cur->next is valid since cur
+ * was just unlinked and free. */
+ cur = prev;
+ continue;
+ }
+
+ prev = cur;
+ }
+}
+
+static void remove_memranges(struct memranges *ranges,
+ resource_t begin, resource_t end,
+ unsigned long unused)
+{
+ struct range_entry *cur;
+ struct range_entry *next;
+ struct range_entry **prev_ptr;
+
+ prev_ptr = &ranges->entries;
+ for (cur = ranges->entries; cur != NULL; cur = next) {
+ resource_t tmp_end;
+
+ /* Cache the next value to handle unlinks. */
+ next = cur->next;
+
+ /* No other ranges are affected. */
+ if (end < cur->begin)
+ break;
+
+ /* The removal range starts after this one. */
+ if (begin > cur->end) {
+ prev_ptr = &cur->next;
+ continue;
+ }
+
+ /* The removal range overlaps with the current entry either
+ * partially or fully. However, we need to adjust the removal
+ * range for any holes. */
+ if (begin <= cur->begin) {
+ begin = cur->begin;
+
+ /* Full removal. */
+ if (end >= cur->end) {
+ begin = cur->end + 1;
+ range_entry_unlink_and_free(prev_ptr, cur);
+ continue;
+ }
+ }
+
+ /* prev_ptr can be set now that the unlink path wasn't taken. */
+ prev_ptr = &cur->next;
+
+ /* Clip the end fragment to do proper splitting. */
+ tmp_end = end;
+ if (end > cur->end)
+ tmp_end = cur->end;
+
+ /* Hole punched in middle of entry. */
+ if (begin > cur->begin && tmp_end < cur->end) {
+ range_list_add(&cur->next, end + 1, cur->end, cur->tag);
+ cur->end = begin - 1;
+ break;
+ }
+
+ /* Removal at beginning. */
+ if (begin == cur->begin)
+ cur->begin = tmp_end + 1;
+
+ /* Removal at end. */
+ if (tmp_end == cur->end)
+ cur->end = begin - 1;
+ }
+}
+
+static void merge_add_memranges(struct memranges *ranges,
+ resource_t begin, resource_t end,
+ unsigned long tag)
+{
+ struct range_entry *cur;
+ struct range_entry **prev_ptr;
+
+ prev_ptr = &ranges->entries;
+
+ /* Remove all existing entries covered by the range. */
+ remove_memranges(ranges, begin, end, -1);
+
+ /* Find the entry to place the new entry after. Since
+ * remove_memranges() was called above there is a guranteed
+ * spot for this new entry. */
+ for (cur = ranges->entries; cur != NULL; cur = cur->next) {
+ /* Found insertion spot before current entry. */
+ if (end < cur->begin)
+ break;
+
+ /* Keep track of previous entry to insert new entry after it. */
+ prev_ptr = &cur->next;
+
+ /* The new entry starts after this one. */
+ if (begin > cur->end)
+ continue;
+
+ }
+
+ /* Add new entry and merge with neighbors. */
+ range_list_add(prev_ptr, begin, end, tag);
+ merge_neighbor_entries(ranges);
+}
+
+typedef void (*range_action_t)(struct memranges *ranges,
+ resource_t begin, resource_t end,
+ unsigned long tag);
+
+static void do_action(struct memranges *ranges,
+ resource_t base, resource_t size, unsigned long tag,
+ range_action_t action)
+{
+ resource_t end;
+ resource_t begin;
+
+ /* The addresses are aligned to 4096 bytes: the begin address is
+ * aligned down while the end address is aligned up to be conservative
+ * about the full range covered. */
+ begin = ALIGN_DOWN(base, 4096);
+ end = begin + size + (base - begin);
+ end = ALIGN_UP(end, 4096) - 1;
+ action(ranges, begin, end, tag);
+}
+
+void memranges_create_hole(struct memranges *ranges,
+ resource_t base, resource_t size)
+{
+ do_action(ranges, base, size, -1, remove_memranges);
+}
+
+void memranges_insert(struct memranges *ranges,
+ resource_t base, resource_t size, unsigned long tag)
+{
+ do_action(ranges, base, size, tag, merge_add_memranges);
+}
+
+struct collect_context {
+ struct memranges *ranges;
+ unsigned long tag;
+};
+
+static void collect_ranges(void *gp, struct device *dev, struct resource *res)
+{
+ struct collect_context *ctx = gp;
+
+ memranges_insert(ctx->ranges, res->base, res->size, ctx->tag);
+}
+
+void memranges_add_resources(struct memranges *ranges,
+ unsigned long mask, unsigned long match,
+ unsigned long tag)
+{
+ struct collect_context context;
+
+ /* Only deal with MEM resources. */
+ mask |= IORESOURCE_MEM;
+ match |= IORESOURCE_MEM;
+
+ context.ranges = ranges;
+ context.tag = tag;
+ search_global_resources(mask, match, collect_ranges, &context);
+}
+
+void memranges_init(struct memranges *ranges,
+ unsigned long mask, unsigned long match,
+ unsigned long tag)
+{
+ ranges->entries = NULL;
+ memranges_add_resources(ranges, mask, match, tag);
+}
+
+void memranges_teardown(struct memranges *ranges)
+{
+ while (ranges->entries != NULL) {
+ range_entry_unlink_and_free(&ranges->entries, ranges->entries);
+ }
+}
+
+void memranges_fill_holes_up_to(struct memranges *ranges,
+ resource_t limit, unsigned long tag)
+{
+ struct range_entry *cur;
+ struct range_entry *prev;
+
+ prev = NULL;
+ for (cur = ranges->entries; cur != NULL; cur = cur->next) {
+ /* First entry. Just set prev. */
+ if (prev == NULL) {
+ prev = cur;
+ continue;
+ }
+
+ /* If the previous entry does not directly preceed the current
+ * entry then add a new entry just after the previous one. */
+ if (range_entry_end(prev) != cur->begin) {
+ resource_t end;
+
+ end = cur->begin - 1;
+ if (end >= limit)
+ end = limit - 1;
+ range_list_add(&prev->next, range_entry_end(prev),
+ end, tag);
+ }
+
+ prev = cur;
+
+ /* Hit the requested range limit. No other entries after this
+ * are affected. */
+ if (cur->begin >= limit)
+ break;
+ }
+
+ /* Handle the case where the limit was never reached. A new entry needs
+ * to be added to cover the range up to the limit. */
+ if (prev != NULL && range_entry_end(prev) < limit)
+ range_list_add(&prev->next, range_entry_end(prev),
+ limit - 1, tag);
+
+ /* Merge all entries that were newly added. */
+ merge_neighbor_entries(ranges);
+}