xref: /openbmc/u-boot/arch/x86/lib/ramtest.c (revision d66ff4ba)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2014 Google, Inc
4  *
5  * From Coreboot src/lib/ramtest.c
6  */
7 
8 #include <common.h>
9 #include <asm/io.h>
10 #include <asm/post.h>
11 
12 static void write_phys(unsigned long addr, u32 value)
13 {
14 #if CONFIG_SSE2
15 	asm volatile(
16 		"movnti %1, (%0)"
17 		: /* outputs */
18 		: "r" (addr), "r" (value) /* inputs */
19 		: /* clobbers */
20 		);
21 #else
22 	writel(value, addr);
23 #endif
24 }
25 
26 static u32 read_phys(unsigned long addr)
27 {
28 	return readl(addr);
29 }
30 
31 static void phys_memory_barrier(void)
32 {
33 #if CONFIG_SSE2
34 	/* Needed for movnti */
35 	asm volatile(
36 		"sfence"
37 		:
38 		:
39 		: "memory"
40 	);
41 #else
42 	asm volatile(""
43 		:
44 		:
45 		: "memory");
46 #endif
47 }
48 
49 void quick_ram_check(void)
50 {
51 	int fail = 0;
52 	u32 backup;
53 
54 	backup = read_phys(CONFIG_RAMBASE);
55 	write_phys(CONFIG_RAMBASE, 0x55555555);
56 	phys_memory_barrier();
57 	if (read_phys(CONFIG_RAMBASE) != 0x55555555)
58 		fail = 1;
59 	write_phys(CONFIG_RAMBASE, 0xaaaaaaaa);
60 	phys_memory_barrier();
61 	if (read_phys(CONFIG_RAMBASE) != 0xaaaaaaaa)
62 		fail = 1;
63 	write_phys(CONFIG_RAMBASE, 0x00000000);
64 	phys_memory_barrier();
65 	if (read_phys(CONFIG_RAMBASE) != 0x00000000)
66 		fail = 1;
67 	write_phys(CONFIG_RAMBASE, 0xffffffff);
68 	phys_memory_barrier();
69 	if (read_phys(CONFIG_RAMBASE) != 0xffffffff)
70 		fail = 1;
71 
72 	write_phys(CONFIG_RAMBASE, backup);
73 	if (fail) {
74 		post_code(POST_RAM_FAILURE);
75 		panic("RAM INIT FAILURE!\n");
76 	}
77 	phys_memory_barrier();
78 }
79