xref: /openbmc/linux/arch/s390/boot/ipl_report.c (revision 2cf1c348)
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 <uapi/asm/ipl.h>
9 #include "boot.h"
10 
11 int __bootdata_preserved(ipl_secure_flag);
12 
13 unsigned long __bootdata_preserved(ipl_cert_list_addr);
14 unsigned long __bootdata_preserved(ipl_cert_list_size);
15 
16 unsigned long __bootdata(early_ipl_comp_list_addr);
17 unsigned long __bootdata(early_ipl_comp_list_size);
18 
19 #define for_each_rb_entry(entry, rb) \
20 	for (entry = rb->entries; \
21 	     (void *) entry + sizeof(*entry) <= (void *) rb + rb->len; \
22 	     entry++)
23 
24 static inline bool intersects(unsigned long addr0, unsigned long size0,
25 			      unsigned long addr1, unsigned long size1)
26 {
27 	return addr0 + size0 > addr1 && addr1 + size1 > addr0;
28 }
29 
30 static unsigned long find_bootdata_space(struct ipl_rb_components *comps,
31 					 struct ipl_rb_certificates *certs,
32 					 unsigned long safe_addr)
33 {
34 	struct ipl_rb_certificate_entry *cert;
35 	struct ipl_rb_component_entry *comp;
36 	size_t size;
37 
38 	/*
39 	 * Find the length for the IPL report boot data
40 	 */
41 	early_ipl_comp_list_size = 0;
42 	for_each_rb_entry(comp, comps)
43 		early_ipl_comp_list_size += sizeof(*comp);
44 	ipl_cert_list_size = 0;
45 	for_each_rb_entry(cert, certs)
46 		ipl_cert_list_size += sizeof(unsigned int) + cert->len;
47 	size = ipl_cert_list_size + early_ipl_comp_list_size;
48 
49 	/*
50 	 * Start from safe_addr to find a free memory area large
51 	 * enough for the IPL report boot data. This area is used
52 	 * for ipl_cert_list_addr/ipl_cert_list_size and
53 	 * early_ipl_comp_list_addr/early_ipl_comp_list_size. It must
54 	 * not overlap with any component or any certificate.
55 	 */
56 repeat:
57 	if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && initrd_data.start && initrd_data.size &&
58 	    intersects(initrd_data.start, initrd_data.size, safe_addr, size))
59 		safe_addr = initrd_data.start + initrd_data.size;
60 	for_each_rb_entry(comp, comps)
61 		if (intersects(safe_addr, size, comp->addr, comp->len)) {
62 			safe_addr = comp->addr + comp->len;
63 			goto repeat;
64 		}
65 	for_each_rb_entry(cert, certs)
66 		if (intersects(safe_addr, size, cert->addr, cert->len)) {
67 			safe_addr = cert->addr + cert->len;
68 			goto repeat;
69 		}
70 	early_ipl_comp_list_addr = safe_addr;
71 	ipl_cert_list_addr = safe_addr + early_ipl_comp_list_size;
72 
73 	return safe_addr + size;
74 }
75 
76 static void copy_components_bootdata(struct ipl_rb_components *comps)
77 {
78 	struct ipl_rb_component_entry *comp, *ptr;
79 
80 	ptr = (struct ipl_rb_component_entry *) early_ipl_comp_list_addr;
81 	for_each_rb_entry(comp, comps)
82 		memcpy(ptr++, comp, sizeof(*ptr));
83 }
84 
85 static void copy_certificates_bootdata(struct ipl_rb_certificates *certs)
86 {
87 	struct ipl_rb_certificate_entry *cert;
88 	void *ptr;
89 
90 	ptr = (void *) ipl_cert_list_addr;
91 	for_each_rb_entry(cert, certs) {
92 		*(unsigned int *) ptr = cert->len;
93 		ptr += sizeof(unsigned int);
94 		memcpy(ptr, (void *) cert->addr, cert->len);
95 		ptr += cert->len;
96 	}
97 }
98 
99 unsigned long read_ipl_report(unsigned long safe_addr)
100 {
101 	struct ipl_rb_certificates *certs;
102 	struct ipl_rb_components *comps;
103 	struct ipl_pl_hdr *pl_hdr;
104 	struct ipl_rl_hdr *rl_hdr;
105 	struct ipl_rb_hdr *rb_hdr;
106 	unsigned long tmp;
107 	void *rl_end;
108 
109 	/*
110 	 * Check if there is a IPL report by looking at the copy
111 	 * of the IPL parameter information block.
112 	 */
113 	if (!ipl_block_valid ||
114 	    !(ipl_block.hdr.flags & IPL_PL_FLAG_IPLSR))
115 		return safe_addr;
116 	ipl_secure_flag = !!(ipl_block.hdr.flags & IPL_PL_FLAG_SIPL);
117 	/*
118 	 * There is an IPL report, to find it load the pointer to the
119 	 * IPL parameter information block from lowcore and skip past
120 	 * the IPL parameter list, then align the address to a double
121 	 * word boundary.
122 	 */
123 	tmp = (unsigned long) S390_lowcore.ipl_parmblock_ptr;
124 	pl_hdr = (struct ipl_pl_hdr *) tmp;
125 	tmp = (tmp + pl_hdr->len + 7) & -8UL;
126 	rl_hdr = (struct ipl_rl_hdr *) tmp;
127 	/* Walk through the IPL report blocks in the IPL Report list */
128 	certs = NULL;
129 	comps = NULL;
130 	rl_end = (void *) rl_hdr + rl_hdr->len;
131 	rb_hdr = (void *) rl_hdr + sizeof(*rl_hdr);
132 	while ((void *) rb_hdr + sizeof(*rb_hdr) < rl_end &&
133 	       (void *) rb_hdr + rb_hdr->len <= rl_end) {
134 
135 		switch (rb_hdr->rbt) {
136 		case IPL_RBT_CERTIFICATES:
137 			certs = (struct ipl_rb_certificates *) rb_hdr;
138 			break;
139 		case IPL_RBT_COMPONENTS:
140 			comps = (struct ipl_rb_components *) rb_hdr;
141 			break;
142 		default:
143 			break;
144 		}
145 
146 		rb_hdr = (void *) rb_hdr + rb_hdr->len;
147 	}
148 
149 	/*
150 	 * With either the component list or the certificate list
151 	 * missing the kernel will stay ignorant of secure IPL.
152 	 */
153 	if (!comps || !certs)
154 		return safe_addr;
155 
156 	/*
157 	 * Copy component and certificate list to a safe area
158 	 * where the decompressed kernel can find them.
159 	 */
160 	safe_addr = find_bootdata_space(comps, certs, safe_addr);
161 	copy_components_bootdata(comps);
162 	copy_certificates_bootdata(certs);
163 
164 	return safe_addr;
165 }
166