xref: /linux/arch/s390/boot/ipl_report.c (revision 5e3992fe72748ed3892be876f09d4d990548b7af)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/init.h>
3 #include <linux/ctype.h>
4 #include <asm/ebcdic.h>
5 #include <asm/sclp.h>
6 #include <asm/sections.h>
7 #include <asm/boot_data.h>
8 #include <asm/physmem_info.h>
9 #include <uapi/asm/ipl.h>
10 #include "boot.h"
11 
12 int __bootdata_preserved(ipl_secure_flag);
13 
14 unsigned long __bootdata_preserved(ipl_cert_list_addr);
15 unsigned long __bootdata_preserved(ipl_cert_list_size);
16 
17 unsigned long __bootdata(early_ipl_comp_list_addr);
18 unsigned long __bootdata(early_ipl_comp_list_size);
19 
20 static struct ipl_rb_certificates *certs;
21 static struct ipl_rb_components *comps;
22 static bool ipl_report_needs_saving;
23 
24 #define for_each_rb_entry(entry, rb) \
25 	for (entry = rb->entries; \
26 	     (void *) entry + sizeof(*entry) <= (void *) rb + rb->len; \
27 	     entry++)
28 
29 static unsigned long get_cert_comp_list_size(void)
30 {
31 	struct ipl_rb_certificate_entry *cert;
32 	struct ipl_rb_component_entry *comp;
33 	size_t size;
34 
35 	/*
36 	 * Find the length for the IPL report boot data
37 	 */
38 	early_ipl_comp_list_size = 0;
39 	for_each_rb_entry(comp, comps)
40 		early_ipl_comp_list_size += sizeof(*comp);
41 	ipl_cert_list_size = 0;
42 	for_each_rb_entry(cert, certs)
43 		ipl_cert_list_size += sizeof(unsigned int) + cert->len;
44 	return ipl_cert_list_size + early_ipl_comp_list_size;
45 }
46 
47 bool ipl_report_certs_intersects(unsigned long addr, unsigned long size,
48 				 unsigned long *intersection_start)
49 {
50 	struct ipl_rb_certificate_entry *cert;
51 
52 	if (!ipl_report_needs_saving)
53 		return false;
54 
55 	for_each_rb_entry(cert, certs) {
56 		if (intersects(addr, size, cert->addr, cert->len)) {
57 			*intersection_start = cert->addr;
58 			return true;
59 		}
60 	}
61 	return false;
62 }
63 
64 static void copy_components_bootdata(void)
65 {
66 	struct ipl_rb_component_entry *comp, *ptr;
67 
68 	ptr = (struct ipl_rb_component_entry *) early_ipl_comp_list_addr;
69 	for_each_rb_entry(comp, comps)
70 		memcpy(ptr++, comp, sizeof(*ptr));
71 }
72 
73 static void copy_certificates_bootdata(void)
74 {
75 	struct ipl_rb_certificate_entry *cert;
76 	void *ptr;
77 
78 	ptr = (void *) ipl_cert_list_addr;
79 	for_each_rb_entry(cert, certs) {
80 		*(unsigned int *) ptr = cert->len;
81 		ptr += sizeof(unsigned int);
82 		memcpy(ptr, (void *) cert->addr, cert->len);
83 		ptr += cert->len;
84 	}
85 }
86 
87 int read_ipl_report(void)
88 {
89 	struct ipl_pl_hdr *pl_hdr;
90 	struct ipl_rl_hdr *rl_hdr;
91 	struct ipl_rb_hdr *rb_hdr;
92 	unsigned long tmp;
93 	void *rl_end;
94 
95 	/*
96 	 * Check if there is a IPL report by looking at the copy
97 	 * of the IPL parameter information block.
98 	 */
99 	if (!ipl_block_valid ||
100 	    !(ipl_block.hdr.flags & IPL_PL_FLAG_IPLSR))
101 		return -1;
102 	ipl_secure_flag = !!(ipl_block.hdr.flags & IPL_PL_FLAG_SIPL);
103 	/*
104 	 * There is an IPL report, to find it load the pointer to the
105 	 * IPL parameter information block from lowcore and skip past
106 	 * the IPL parameter list, then align the address to a double
107 	 * word boundary.
108 	 */
109 	tmp = (unsigned long) S390_lowcore.ipl_parmblock_ptr;
110 	pl_hdr = (struct ipl_pl_hdr *) tmp;
111 	tmp = (tmp + pl_hdr->len + 7) & -8UL;
112 	rl_hdr = (struct ipl_rl_hdr *) tmp;
113 	/* Walk through the IPL report blocks in the IPL Report list */
114 	certs = NULL;
115 	comps = NULL;
116 	rl_end = (void *) rl_hdr + rl_hdr->len;
117 	rb_hdr = (void *) rl_hdr + sizeof(*rl_hdr);
118 	while ((void *) rb_hdr + sizeof(*rb_hdr) < rl_end &&
119 	       (void *) rb_hdr + rb_hdr->len <= rl_end) {
120 
121 		switch (rb_hdr->rbt) {
122 		case IPL_RBT_CERTIFICATES:
123 			certs = (struct ipl_rb_certificates *) rb_hdr;
124 			break;
125 		case IPL_RBT_COMPONENTS:
126 			comps = (struct ipl_rb_components *) rb_hdr;
127 			break;
128 		default:
129 			break;
130 		}
131 
132 		rb_hdr = (void *) rb_hdr + rb_hdr->len;
133 	}
134 
135 	/*
136 	 * With either the component list or the certificate list
137 	 * missing the kernel will stay ignorant of secure IPL.
138 	 */
139 	if (!comps || !certs) {
140 		certs = NULL;
141 		return -1;
142 	}
143 
144 	ipl_report_needs_saving = true;
145 	physmem_reserve(RR_IPLREPORT, (unsigned long)pl_hdr,
146 			(unsigned long)rl_end - (unsigned long)pl_hdr);
147 	return 0;
148 }
149 
150 void save_ipl_cert_comp_list(void)
151 {
152 	unsigned long size;
153 
154 	if (!ipl_report_needs_saving)
155 		return;
156 
157 	size = get_cert_comp_list_size();
158 	early_ipl_comp_list_addr = physmem_alloc_top_down(RR_CERT_COMP_LIST, size, sizeof(int));
159 	ipl_cert_list_addr = early_ipl_comp_list_addr + early_ipl_comp_list_size;
160 
161 	copy_components_bootdata();
162 	copy_certificates_bootdata();
163 	physmem_free(RR_IPLREPORT);
164 	ipl_report_needs_saving = false;
165 }
166