1 /* SPDX-License-Identifier: GPL-2.0-only */
2
3 #if ENV_X86
4 #include <cpu/x86/pae.h>
5 #else
6 #define memset_pae(a, b, c, d, e) 0
7 #define PAE_PGTL_ALIGN 0
8 #define PAE_PGTL_SIZE 0
9 #define PAE_VMEM_ALIGN 0
10 #define PAE_VMEM_SIZE 0
11 #endif
12
13 #include <memrange.h>
14 #include <bootmem.h>
15 #include <bootstate.h>
16 #include <symbols.h>
17 #include <console/console.h>
18 #include <arch/memory_clear.h>
19 #include <string.h>
20 #include <security/memory/memory.h>
21 #include <cbmem.h>
22 #include <acpi/acpi.h>
23
24 /* Helper to find free space for memset_pae. */
get_free_memory_range(struct memranges * mem,const resource_t align,const resource_t size)25 static uintptr_t get_free_memory_range(struct memranges *mem,
26 const resource_t align,
27 const resource_t size)
28 {
29 const struct range_entry *r;
30
31 /* Find a spot for virtual memory address */
32 memranges_each_entry(r, mem) {
33 if (range_entry_tag(r) != BM_MEM_RAM)
34 continue;
35
36 if (ALIGN_UP(range_entry_base(r) + size, align) + size >
37 range_entry_end(r))
38 continue;
39
40 return ALIGN_UP(range_entry_base(r) + size, align);
41 }
42 printk(BIOS_ERR, "%s: Couldn't find free memory range\n", __func__);
43
44 return 0;
45 }
46
47 /*
48 * Clears all memory regions marked as BM_MEM_RAM.
49 * Uses memset_pae if the memory region can't be accessed by memset and
50 * architecture is x86.
51 *
52 * @return 0 on success, 1 on error
53 */
clear_memory(void * unused)54 static void clear_memory(void *unused)
55 {
56 const struct range_entry *r;
57 struct memranges mem;
58 uintptr_t pgtbl, vmem_addr;
59
60 if (acpi_is_wakeup_s3())
61 return;
62
63 if (!security_clear_dram_request())
64 return;
65
66 /* FSP1.0 is marked as MMIO and won't appear here */
67
68 memranges_init(&mem, IORESOURCE_MEM | IORESOURCE_FIXED |
69 IORESOURCE_STORED | IORESOURCE_ASSIGNED |
70 IORESOURCE_CACHEABLE,
71 IORESOURCE_MEM | IORESOURCE_FIXED |
72 IORESOURCE_STORED | IORESOURCE_ASSIGNED |
73 IORESOURCE_CACHEABLE,
74 BM_MEM_RAM);
75
76 /* Add reserved entries */
77 void *baseptr = NULL;
78 size_t size = 0;
79
80 /* Only skip CBMEM, stage program, stack and heap are included there. */
81
82 cbmem_get_region(&baseptr, &size);
83 memranges_insert(&mem, (uintptr_t)baseptr, size, BM_MEM_TABLE);
84
85 if (ENV_X86) {
86 /* Find space for PAE enabled memset */
87 pgtbl = get_free_memory_range(&mem, PAE_PGTL_ALIGN, PAE_PGTL_SIZE);
88
89 /* Don't touch page tables while clearing */
90 memranges_insert(&mem, pgtbl, PAE_PGTL_SIZE, BM_MEM_TABLE);
91
92 vmem_addr = get_free_memory_range(&mem, PAE_VMEM_ALIGN, PAE_VMEM_SIZE);
93
94 printk(BIOS_SPEW, "%s: pgtbl at %p, virt memory at %p\n",
95 __func__, (void *)pgtbl, (void *)vmem_addr);
96 }
97
98 /* Now clear all usable DRAM */
99 memranges_each_entry(r, &mem) {
100 if (range_entry_tag(r) != BM_MEM_RAM)
101 continue;
102 printk(BIOS_DEBUG, "%s: Clearing DRAM %016llx-%016llx\n",
103 __func__, range_entry_base(r), range_entry_end(r));
104
105 /* Does regular memset work? */
106 if (sizeof(resource_t) == sizeof(void *) ||
107 !(range_entry_end(r) >> (sizeof(void *) * 8))) {
108 /* fastpath */
109 memset((void *)(uintptr_t)range_entry_base(r), 0,
110 range_entry_size(r));
111 }
112 /* Use PAE if available */
113 else if (ENV_X86) {
114 if (memset_pae(range_entry_base(r), 0,
115 range_entry_size(r), (void *)pgtbl,
116 (void *)vmem_addr))
117 printk(BIOS_ERR, "%s: Failed to memset "
118 "memory\n", __func__);
119 } else {
120 printk(BIOS_ERR, "%s: Failed to memset memory\n",
121 __func__);
122 }
123 }
124
125 if (ENV_X86) {
126 /* Clear previously skipped memory reserved for pagetables */
127 printk(BIOS_DEBUG, "%s: Clearing DRAM %016lx-%016lx\n",
128 __func__, pgtbl, pgtbl + PAE_PGTL_SIZE);
129
130 memset((void *)pgtbl, 0, PAE_PGTL_SIZE);
131 }
132
133 memranges_teardown(&mem);
134 }
135
136 /* After DEV_INIT as MTRRs needs to be configured on x86 */
137 BOOT_STATE_INIT_ENTRY(BS_DEV_INIT, BS_ON_EXIT, clear_memory, NULL);
138