xref: /openbmc/u-boot/arch/x86/lib/ramtest.c (revision c5f18a0b)
1 /*
2  * Copyright (c) 2014 Google, Inc
3  *
4  * From Coreboot src/lib/ramtest.c
5  *
6  * SPDX-License-Identifier:	GPL-2.0
7  */
8 
9 #include <common.h>
10 #include <asm/io.h>
11 #include <asm/post.h>
12 
13 static void write_phys(unsigned long addr, u32 value)
14 {
15 #if CONFIG_SSE2
16 	asm volatile(
17 		"movnti %1, (%0)"
18 		: /* outputs */
19 		: "r" (addr), "r" (value) /* inputs */
20 		: /* clobbers */
21 		);
22 #else
23 	writel(value, addr);
24 #endif
25 }
26 
27 static u32 read_phys(unsigned long addr)
28 {
29 	return readl(addr);
30 }
31 
32 static void phys_memory_barrier(void)
33 {
34 #if CONFIG_SSE2
35 	/* Needed for movnti */
36 	asm volatile(
37 		"sfence"
38 		:
39 		:
40 		: "memory"
41 	);
42 #else
43 	asm volatile(""
44 		:
45 		:
46 		: "memory");
47 #endif
48 }
49 
50 void quick_ram_check(void)
51 {
52 	int fail = 0;
53 	u32 backup;
54 
55 	backup = read_phys(CONFIG_RAMBASE);
56 	write_phys(CONFIG_RAMBASE, 0x55555555);
57 	phys_memory_barrier();
58 	if (read_phys(CONFIG_RAMBASE) != 0x55555555)
59 		fail = 1;
60 	write_phys(CONFIG_RAMBASE, 0xaaaaaaaa);
61 	phys_memory_barrier();
62 	if (read_phys(CONFIG_RAMBASE) != 0xaaaaaaaa)
63 		fail = 1;
64 	write_phys(CONFIG_RAMBASE, 0x00000000);
65 	phys_memory_barrier();
66 	if (read_phys(CONFIG_RAMBASE) != 0x00000000)
67 		fail = 1;
68 	write_phys(CONFIG_RAMBASE, 0xffffffff);
69 	phys_memory_barrier();
70 	if (read_phys(CONFIG_RAMBASE) != 0xffffffff)
71 		fail = 1;
72 
73 	write_phys(CONFIG_RAMBASE, backup);
74 	if (fail) {
75 		post_code(POST_RAM_FAILURE);
76 		panic("RAM INIT FAILURE!\n");
77 	}
78 	phys_memory_barrier();
79 }
80