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authorPatrick Georgi <patrick.georgi@secunet.com>2013-02-21 14:03:47 +0100
committerPeter Stuge <peter@stuge.se>2013-02-22 16:04:03 +0100
commit12781422d5ee2afcfe8da6a3f1b4f6c9d257dec8 (patch)
tree56595f4fb1848f9a9e10db5caed451fabc04a16d /util/nvramtool/lbtable.c
parentfbf078311f37ae392b1c97dd5271035f1a056486 (diff)
downloadcoreboot-12781422d5ee2afcfe8da6a3f1b4f6c9d257dec8.tar.xz
nvramtool: reduce memory mapping
Instead of trying to map the first megabyte, only map what is required to read the tables. Change-Id: I9139dbc8fd1dd768bef7ab85c27cd4c18e2931b3 Signed-off-by: Patrick Georgi <patrick.georgi@secunet.com> Reviewed-on: http://review.coreboot.org/2485 Tested-by: build bot (Jenkins) Reviewed-by: Peter Stuge <peter@stuge.se>
Diffstat (limited to 'util/nvramtool/lbtable.c')
-rw-r--r--util/nvramtool/lbtable.c90
1 files changed, 47 insertions, 43 deletions
diff --git a/util/nvramtool/lbtable.c b/util/nvramtool/lbtable.c
index 7a968b7222..5f1f22d90b 100644
--- a/util/nvramtool/lbtable.c
+++ b/util/nvramtool/lbtable.c
@@ -200,19 +200,15 @@ static const mem_range_t mem_ranges[NUM_MEM_RANGES] =
{0x000f0000, 0x000fffff}
};
-/* This is the number of bytes of physical memory to map, starting at physical
- * address 0. This value must be large enough to contain all memory ranges
- * specified in mem_ranges above plus the maximum possible size of the
- * coreboot table (since the start of the table could potentially occur at
- * the end of the last memory range).
- */
-static const size_t BYTES_TO_MAP = (1024 * 1024);
-
/* Pointer to low physical memory that we access by calling mmap() on
* /dev/mem.
*/
static const void *low_phys_mem;
-static unsigned long low_phys_base = 0;
+/* impossible value since not page aligned: first map request will happen */
+static unsigned long low_phys_base = 0x1;
+
+/* count of mapped pages */
+static unsigned long mapped_pages = 0;
/* Pointer to coreboot table. */
static const struct lb_header *lbtable = NULL;
@@ -243,6 +239,37 @@ static const hexdump_format_t format =
((unsigned long) paddr) - low_phys_base)
/****************************************************************************
+ * map_pages
+ *
+ * Maps just enough pages to cover base_address + length
+ * and updates affected variables
+ ****************************************************************************/
+static void map_pages(unsigned long base_address, unsigned long length)
+{
+ unsigned long num_pages = (length +
+ (base_address & (getpagesize() - 1)) +
+ getpagesize() - 1) >> 12;
+ base_address &= ~(getpagesize() - 1);
+
+ /* no need to do anything */
+ if ((low_phys_base == base_address) && (mapped_pages == num_pages)) {
+ return;
+ }
+
+ if (low_phys_mem) {
+ munmap((void *)low_phys_mem, mapped_pages << 12);
+ }
+ if ((low_phys_mem = mmap(NULL, num_pages << 12, PROT_READ, MAP_SHARED, fd,
+ (off_t) base_address)) == MAP_FAILED) {
+ fprintf(stderr,
+ "%s: Failed to mmap /dev/mem at %lx: %s\n",
+ prog_name, base_address, strerror(errno));
+ exit(1);
+ }
+ low_phys_base = base_address;
+}
+
+/****************************************************************************
* get_lbtable
*
* Find the coreboot table and set global variable lbtable to point to it.
@@ -264,20 +291,11 @@ void get_lbtable(void)
exit(1);
}
- if ((low_phys_mem =
- mmap(NULL, BYTES_TO_MAP, PROT_READ, MAP_SHARED, fd, 0))
- == MAP_FAILED) {
- fprintf(stderr, "%s: Failed to mmap /dev/mem: %s\n", prog_name,
- strerror(errno));
- exit(1);
- }
-
bad_header_count = 0;
bad_table_count = 0;
for (i = 0; i < NUM_MEM_RANGES; i++) {
- lbtable = lbtable_scan(phystov(mem_ranges[i].start),
- phystov(mem_ranges[i].end),
+ lbtable = lbtable_scan(mem_ranges[i].start, mem_ranges[i].end,
&bad_headers, &bad_tables);
if (lbtable != NULL)
@@ -421,8 +439,7 @@ void list_lbtable_item(const char item[])
* first and last bytes of the chunk of memory to be scanned. For instance,
* values of 0x10000000 and 0x1000ffff for 'start' and 'end' specify a 64k
* chunk of memory starting at address 0x10000000. 'start' and 'end' are
- * virtual addresses in the address space of the current process. They
- * represent a chunk of memory obtained by calling mmap() on /dev/mem.
+ * physical addresses.
*
* If a coreboot table is found, return a pointer to it. Otherwise return
* NULL. On return, *bad_header_count and *bad_table_count are set as
@@ -444,7 +461,7 @@ static const struct lb_header *lbtable_scan(unsigned long start,
static const char signature[4] = { 'L', 'B', 'I', 'O' };
const struct lb_header *table;
const struct lb_forward *forward;
- const uint32_t *p;
+ unsigned long p;
uint32_t sig;
assert(end >= start);
@@ -459,14 +476,15 @@ static const struct lb_header *lbtable_scan(unsigned long start,
* for 'start' and 'end': even weird boundary cases like 0x00000000 and
* 0xffffffff on a 32-bit architecture.
*/
- for (p = (const uint32_t *)start;
- (((unsigned long)p) <= end) &&
- ((end - (unsigned long)p) >= (sizeof(uint32_t) - 1)); p += 4) {
- if (*p != sig)
+ map_pages(start, end - start);
+ for (p = start;
+ (p <= end) &&
+ (end - p >= (sizeof(uint32_t) - 1)); p += 4) {
+ if (*(uint32_t*)phystov(p) != sig)
continue;
/* We found a valid signature. */
- table = (const struct lb_header *)p;
+ table = (const struct lb_header *)phystov(p);
/* validate header checksum */
if (compute_ip_checksum((void *)table, sizeof(*table))) {
@@ -474,6 +492,7 @@ static const struct lb_header *lbtable_scan(unsigned long start,
continue;
}
+ map_pages(p, table->table_bytes + sizeof(*table));
/* validate table checksum */
if (table->table_checksum !=
compute_ip_checksum(((char *)table) + sizeof(*table),
@@ -490,22 +509,7 @@ static const struct lb_header *lbtable_scan(unsigned long start,
if (forward) {
uint64_t new_phys = forward->forward;
-
- new_phys &= ~(getpagesize() - 1);
-
- munmap((void *)low_phys_mem, BYTES_TO_MAP);
- if ((low_phys_mem =
- mmap(NULL, BYTES_TO_MAP, PROT_READ, MAP_SHARED, fd,
- (off_t) new_phys)) == MAP_FAILED) {
- fprintf(stderr,
- "%s: Failed to mmap /dev/mem: %s\n",
- prog_name, strerror(errno));
- exit(1);
- }
- low_phys_base = new_phys;
- table =
- lbtable_scan(phystov(low_phys_base),
- phystov(low_phys_base + BYTES_TO_MAP),
+ table = lbtable_scan(new_phys, new_phys + getpagesize(),
bad_header_count, bad_table_count);
}
return table;