https://github.com/torvalds/linux
Tip revision: b7b275e60bcd5f89771e865a8239325f86d9927d authored by Linus Torvalds on 27 November 2022, 21:31:48 UTC
Linux 6.1-rc7
Linux 6.1-rc7
Tip revision: b7b275e
memtest.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/memblock.h>
static u64 patterns[] __initdata = {
/* The first entry has to be 0 to leave memtest with zeroed memory */
0,
0xffffffffffffffffULL,
0x5555555555555555ULL,
0xaaaaaaaaaaaaaaaaULL,
0x1111111111111111ULL,
0x2222222222222222ULL,
0x4444444444444444ULL,
0x8888888888888888ULL,
0x3333333333333333ULL,
0x6666666666666666ULL,
0x9999999999999999ULL,
0xccccccccccccccccULL,
0x7777777777777777ULL,
0xbbbbbbbbbbbbbbbbULL,
0xddddddddddddddddULL,
0xeeeeeeeeeeeeeeeeULL,
0x7a6c7258554e494cULL, /* yeah ;-) */
};
static void __init reserve_bad_mem(u64 pattern, phys_addr_t start_bad, phys_addr_t end_bad)
{
pr_info(" %016llx bad mem addr %pa - %pa reserved\n",
cpu_to_be64(pattern), &start_bad, &end_bad);
memblock_reserve(start_bad, end_bad - start_bad);
}
static void __init memtest(u64 pattern, phys_addr_t start_phys, phys_addr_t size)
{
u64 *p, *start, *end;
phys_addr_t start_bad, last_bad;
phys_addr_t start_phys_aligned;
const size_t incr = sizeof(pattern);
start_phys_aligned = ALIGN(start_phys, incr);
start = __va(start_phys_aligned);
end = start + (size - (start_phys_aligned - start_phys)) / incr;
start_bad = 0;
last_bad = 0;
for (p = start; p < end; p++)
*p = pattern;
for (p = start; p < end; p++, start_phys_aligned += incr) {
if (*p == pattern)
continue;
if (start_phys_aligned == last_bad + incr) {
last_bad += incr;
continue;
}
if (start_bad)
reserve_bad_mem(pattern, start_bad, last_bad + incr);
start_bad = last_bad = start_phys_aligned;
}
if (start_bad)
reserve_bad_mem(pattern, start_bad, last_bad + incr);
}
static void __init do_one_pass(u64 pattern, phys_addr_t start, phys_addr_t end)
{
u64 i;
phys_addr_t this_start, this_end;
for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, &this_start,
&this_end, NULL) {
this_start = clamp(this_start, start, end);
this_end = clamp(this_end, start, end);
if (this_start < this_end) {
pr_info(" %pa - %pa pattern %016llx\n",
&this_start, &this_end, cpu_to_be64(pattern));
memtest(pattern, this_start, this_end - this_start);
}
}
}
/* default is disabled */
static unsigned int memtest_pattern __initdata;
static int __init parse_memtest(char *arg)
{
int ret = 0;
if (arg)
ret = kstrtouint(arg, 0, &memtest_pattern);
else
memtest_pattern = ARRAY_SIZE(patterns);
return ret;
}
early_param("memtest", parse_memtest);
void __init early_memtest(phys_addr_t start, phys_addr_t end)
{
unsigned int i;
unsigned int idx = 0;
if (!memtest_pattern)
return;
pr_info("early_memtest: # of tests: %u\n", memtest_pattern);
for (i = memtest_pattern-1; i < UINT_MAX; --i) {
idx = i % ARRAY_SIZE(patterns);
do_one_pass(patterns[idx], start, end);
}
}