// 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);	}}