Patrick Georgi (patrick@georgi-clan.de) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/2485
-gerrit
commit 97b58e84dfcf4b3b543ac3d75f77c5d66c91fe30 Author: Patrick Georgi patrick.georgi@secunet.com Date: Thu Feb 21 14:03:47 2013 +0100
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 --- util/nvramtool/lbtable.c | 90 +++++++++++++++++++++++++----------------------- 1 file changed, 47 insertions(+), 43 deletions(-)
diff --git a/util/nvramtool/lbtable.c b/util/nvramtool/lbtable.c index 7a968b7..5f1f22d 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;