1 // SPDX-License-Identifier: GPL-2.0
2 #define boot_fmt(fmt) "startup: " fmt
3 #include <linux/string.h>
4 #include <linux/elf.h>
5 #include <asm/page-states.h>
6 #include <asm/boot_data.h>
7 #include <asm/extmem.h>
8 #include <asm/sections.h>
9 #include <asm/diag288.h>
10 #include <asm/maccess.h>
11 #include <asm/machine.h>
12 #include <asm/sysinfo.h>
13 #include <asm/cpu_mf.h>
14 #include <asm/setup.h>
15 #include <asm/timex.h>
16 #include <asm/kasan.h>
17 #include <asm/kexec.h>
18 #include <asm/sclp.h>
19 #include <asm/diag.h>
20 #include <asm/uv.h>
21 #include <asm/abs_lowcore.h>
22 #include <asm/physmem_info.h>
23 #include "decompressor.h"
24 #include "boot.h"
25 #include "uv.h"
26
27 struct vm_layout __bootdata_preserved(vm_layout);
28 unsigned long __bootdata_preserved(__abs_lowcore);
29 unsigned long __bootdata_preserved(__memcpy_real_area);
30 pte_t *__bootdata_preserved(memcpy_real_ptep);
31 unsigned long __bootdata_preserved(VMALLOC_START);
32 unsigned long __bootdata_preserved(VMALLOC_END);
33 struct page *__bootdata_preserved(vmemmap);
34 unsigned long __bootdata_preserved(vmemmap_size);
35 unsigned long __bootdata_preserved(MODULES_VADDR);
36 unsigned long __bootdata_preserved(MODULES_END);
37 unsigned long __bootdata_preserved(max_mappable);
38 unsigned long __bootdata_preserved(page_noexec_mask);
39 unsigned long __bootdata_preserved(segment_noexec_mask);
40 unsigned long __bootdata_preserved(region_noexec_mask);
41 union tod_clock __bootdata_preserved(tod_clock_base);
42 u64 __bootdata_preserved(clock_comparator_max) = -1UL;
43
44 u64 __bootdata_preserved(stfle_fac_list[16]);
45 struct oldmem_data __bootdata_preserved(oldmem_data);
46
47 static char sysinfo_page[PAGE_SIZE] __aligned(PAGE_SIZE);
48
detect_machine_type(void)49 static void detect_machine_type(void)
50 {
51 struct sysinfo_3_2_2 *vmms = (struct sysinfo_3_2_2 *)&sysinfo_page;
52
53 /* Check current-configuration-level */
54 if (stsi(NULL, 0, 0, 0) <= 2) {
55 set_machine_feature(MFEATURE_LPAR);
56 return;
57 }
58 /* Get virtual-machine cpu information. */
59 if (stsi(vmms, 3, 2, 2) || !vmms->count)
60 return;
61 /* Detect known hypervisors */
62 if (!memcmp(vmms->vm[0].cpi, "\xd2\xe5\xd4", 3))
63 set_machine_feature(MFEATURE_KVM);
64 else if (!memcmp(vmms->vm[0].cpi, "\xa9\x61\xe5\xd4", 4))
65 set_machine_feature(MFEATURE_VM);
66 }
67
detect_diag288(void)68 static void detect_diag288(void)
69 {
70 /* "BEGIN" in EBCDIC character set */
71 static const char cmd[] = "\xc2\xc5\xc7\xc9\xd5";
72 unsigned long action, len;
73
74 action = machine_is_vm() ? (unsigned long)cmd : LPARWDT_RESTART;
75 len = machine_is_vm() ? sizeof(cmd) : 0;
76 if (__diag288(WDT_FUNC_INIT, MIN_INTERVAL, action, len))
77 return;
78 __diag288(WDT_FUNC_CANCEL, 0, 0, 0);
79 set_machine_feature(MFEATURE_DIAG288);
80 }
81
detect_diag9c(void)82 static void detect_diag9c(void)
83 {
84 unsigned int cpu;
85 int rc = 1;
86
87 cpu = stap();
88 asm_inline volatile(
89 " diag %[cpu],%%r0,0x9c\n"
90 "0: lhi %[rc],0\n"
91 "1:\n"
92 EX_TABLE(0b, 1b)
93 : [rc] "+d" (rc)
94 : [cpu] "d" (cpu)
95 : "cc", "memory");
96 if (!rc)
97 set_machine_feature(MFEATURE_DIAG9C);
98 }
99
reset_tod_clock(void)100 static void reset_tod_clock(void)
101 {
102 union tod_clock clk;
103
104 if (store_tod_clock_ext_cc(&clk) == 0)
105 return;
106 /* TOD clock not running. Set the clock to Unix Epoch. */
107 if (set_tod_clock(TOD_UNIX_EPOCH) || store_tod_clock_ext_cc(&clk))
108 disabled_wait();
109 memset(&tod_clock_base, 0, sizeof(tod_clock_base));
110 tod_clock_base.tod = TOD_UNIX_EPOCH;
111 get_lowcore()->last_update_clock = TOD_UNIX_EPOCH;
112 }
113
detect_facilities(void)114 static void detect_facilities(void)
115 {
116 if (cpu_has_edat1())
117 local_ctl_set_bit(0, CR0_EDAT_BIT);
118 page_noexec_mask = -1UL;
119 segment_noexec_mask = -1UL;
120 region_noexec_mask = -1UL;
121 if (!cpu_has_nx()) {
122 page_noexec_mask &= ~_PAGE_NOEXEC;
123 segment_noexec_mask &= ~_SEGMENT_ENTRY_NOEXEC;
124 region_noexec_mask &= ~_REGION_ENTRY_NOEXEC;
125 }
126 if (IS_ENABLED(CONFIG_PCI) && test_facility(153))
127 set_machine_feature(MFEATURE_PCI_MIO);
128 reset_tod_clock();
129 if (test_facility(139) && (tod_clock_base.tod >> 63)) {
130 /* Enable signed clock comparator comparisons */
131 set_machine_feature(MFEATURE_SCC);
132 clock_comparator_max = -1UL >> 1;
133 local_ctl_set_bit(0, CR0_CLOCK_COMPARATOR_SIGN_BIT);
134 }
135 if (test_facility(50) && test_facility(73)) {
136 set_machine_feature(MFEATURE_TX);
137 local_ctl_set_bit(0, CR0_TRANSACTIONAL_EXECUTION_BIT);
138 }
139 if (cpu_has_vx())
140 local_ctl_set_bit(0, CR0_VECTOR_BIT);
141 }
142
cmma_test_essa(void)143 static int cmma_test_essa(void)
144 {
145 unsigned long tmp = 0;
146 int rc = 1;
147
148 /* Test ESSA_GET_STATE */
149 asm_inline volatile(
150 " .insn rrf,0xb9ab0000,%[tmp],%[tmp],%[cmd],0\n"
151 "0: lhi %[rc],0\n"
152 "1:\n"
153 EX_TABLE(0b, 1b)
154 : [rc] "+d" (rc), [tmp] "+d" (tmp)
155 : [cmd] "i" (ESSA_GET_STATE)
156 : "cc", "memory");
157 return rc;
158 }
159
cmma_init(void)160 static void cmma_init(void)
161 {
162 if (!cmma_flag)
163 return;
164 if (cmma_test_essa()) {
165 cmma_flag = 0;
166 return;
167 }
168 if (test_facility(147))
169 cmma_flag = 2;
170 }
171
setup_lpp(void)172 static void setup_lpp(void)
173 {
174 get_lowcore()->current_pid = 0;
175 get_lowcore()->lpp = LPP_MAGIC;
176 if (test_facility(40))
177 lpp(&get_lowcore()->lpp);
178 }
179
180 #ifdef CONFIG_KERNEL_UNCOMPRESSED
mem_safe_offset(void)181 static unsigned long mem_safe_offset(void)
182 {
183 return (unsigned long)_compressed_start;
184 }
185
deploy_kernel(void * output)186 static void deploy_kernel(void *output)
187 {
188 void *uncompressed_start = (void *)_compressed_start;
189
190 if (output == uncompressed_start)
191 return;
192 memmove(output, uncompressed_start, vmlinux.image_size);
193 memset(uncompressed_start, 0, vmlinux.image_size);
194 }
195 #endif
196
rescue_initrd(unsigned long min,unsigned long max)197 static void rescue_initrd(unsigned long min, unsigned long max)
198 {
199 unsigned long old_addr, addr, size;
200
201 if (!IS_ENABLED(CONFIG_BLK_DEV_INITRD))
202 return;
203 if (!get_physmem_reserved(RR_INITRD, &addr, &size))
204 return;
205 if (addr >= min && addr + size <= max)
206 return;
207 old_addr = addr;
208 physmem_free(RR_INITRD);
209 addr = physmem_alloc_or_die(RR_INITRD, size, 0);
210 memmove((void *)addr, (void *)old_addr, size);
211 }
212
copy_bootdata(void)213 static void copy_bootdata(void)
214 {
215 if (__boot_data_end - __boot_data_start != vmlinux.bootdata_size)
216 boot_panic(".boot.data section size mismatch\n");
217 memcpy((void *)vmlinux.bootdata_off, __boot_data_start, vmlinux.bootdata_size);
218 if (__boot_data_preserved_end - __boot_data_preserved_start != vmlinux.bootdata_preserved_size)
219 boot_panic(".boot.preserved.data section size mismatch\n");
220 memcpy((void *)vmlinux.bootdata_preserved_off, __boot_data_preserved_start, vmlinux.bootdata_preserved_size);
221 }
222
kaslr_adjust_relocs(unsigned long min_addr,unsigned long max_addr,unsigned long offset,unsigned long phys_offset)223 static void kaslr_adjust_relocs(unsigned long min_addr, unsigned long max_addr,
224 unsigned long offset, unsigned long phys_offset)
225 {
226 int *reloc;
227 long loc;
228
229 /* Adjust R_390_64 relocations */
230 for (reloc = (int *)__vmlinux_relocs_64_start; reloc < (int *)__vmlinux_relocs_64_end; reloc++) {
231 loc = (long)*reloc + phys_offset;
232 if (loc < min_addr || loc > max_addr)
233 boot_panic("64-bit relocation outside of kernel!\n");
234 *(u64 *)loc += offset;
235 }
236 }
237
kaslr_adjust_got(unsigned long offset)238 static void kaslr_adjust_got(unsigned long offset)
239 {
240 u64 *entry;
241
242 /*
243 * Adjust GOT entries, except for ones for undefined weak symbols
244 * that resolved to zero. This also skips the first three reserved
245 * entries on s390x that are zero.
246 */
247 for (entry = (u64 *)vmlinux.got_start; entry < (u64 *)vmlinux.got_end; entry++) {
248 if (*entry)
249 *entry += offset;
250 }
251 }
252
253 /*
254 * Merge information from several sources into a single ident_map_size value.
255 * "ident_map_size" represents the upper limit of physical memory we may ever
256 * reach. It might not be all online memory, but also include standby (offline)
257 * memory or memory areas reserved for other means (e.g., memory devices such as
258 * virtio-mem).
259 *
260 * "ident_map_size" could be lower then actual standby/reserved or even online
261 * memory present, due to limiting factors. We should never go above this limit.
262 * It is the size of our identity mapping.
263 *
264 * Consider the following factors:
265 * 1. max_physmem_end - end of physical memory online, standby or reserved.
266 * Always >= end of the last online memory range (get_physmem_online_end()).
267 * 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the
268 * kernel is able to support.
269 * 3. "mem=" kernel command line option which limits physical memory usage.
270 * 4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as
271 * crash kernel.
272 * 5. "hsa" size which is a memory limit when the kernel is executed during
273 * zfcp/nvme dump.
274 */
setup_ident_map_size(unsigned long max_physmem_end)275 static void setup_ident_map_size(unsigned long max_physmem_end)
276 {
277 unsigned long hsa_size;
278
279 ident_map_size = max_physmem_end;
280 if (memory_limit)
281 ident_map_size = min(ident_map_size, memory_limit);
282 ident_map_size = min(ident_map_size, 1UL << MAX_PHYSMEM_BITS);
283
284 #ifdef CONFIG_CRASH_DUMP
285 if (oldmem_data.start) {
286 __kaslr_enabled = 0;
287 ident_map_size = min(ident_map_size, oldmem_data.size);
288 boot_debug("kdump memory limit: 0x%016lx\n", oldmem_data.size);
289 } else if (ipl_block_valid && is_ipl_block_dump()) {
290 __kaslr_enabled = 0;
291 if (!sclp_early_get_hsa_size(&hsa_size) && hsa_size) {
292 ident_map_size = min(ident_map_size, hsa_size);
293 boot_debug("Stand-alone dump limit: 0x%016lx\n", hsa_size);
294 }
295 }
296 #endif
297 boot_debug("Identity map size: 0x%016lx\n", ident_map_size);
298 }
299
300 #define FIXMAP_SIZE round_up(MEMCPY_REAL_SIZE + ABS_LOWCORE_MAP_SIZE, sizeof(struct lowcore))
301
get_vmem_size(unsigned long identity_size,unsigned long vmemmap_size,unsigned long vmalloc_size,unsigned long rte_size)302 static unsigned long get_vmem_size(unsigned long identity_size,
303 unsigned long vmemmap_size,
304 unsigned long vmalloc_size,
305 unsigned long rte_size)
306 {
307 unsigned long max_mappable, vsize;
308
309 max_mappable = max(identity_size, MAX_DCSS_ADDR);
310 vsize = round_up(SZ_2G + max_mappable, rte_size) +
311 round_up(vmemmap_size, rte_size) +
312 FIXMAP_SIZE + MODULES_LEN + KASLR_LEN;
313 if (IS_ENABLED(CONFIG_KMSAN))
314 vsize += MODULES_LEN * 2;
315 return size_add(vsize, vmalloc_size);
316 }
317
setup_kernel_memory_layout(unsigned long kernel_size)318 static unsigned long setup_kernel_memory_layout(unsigned long kernel_size)
319 {
320 unsigned long vmemmap_start;
321 unsigned long kernel_start;
322 unsigned long asce_limit;
323 unsigned long rte_size;
324 unsigned long pages;
325 unsigned long vsize;
326 unsigned long vmax;
327
328 pages = ident_map_size / PAGE_SIZE;
329 /* vmemmap contains a multiple of PAGES_PER_SECTION struct pages */
330 vmemmap_size = SECTION_ALIGN_UP(pages) * sizeof(struct page);
331
332 /* choose kernel address space layout: 4 or 3 levels. */
333 BUILD_BUG_ON(!IS_ALIGNED(TEXT_OFFSET, THREAD_SIZE));
334 BUILD_BUG_ON(!IS_ALIGNED(__NO_KASLR_START_KERNEL, THREAD_SIZE));
335 BUILD_BUG_ON(__NO_KASLR_END_KERNEL > _REGION1_SIZE);
336 vsize = get_vmem_size(ident_map_size, vmemmap_size, vmalloc_size, _REGION3_SIZE);
337 boot_debug("vmem size estimated: 0x%016lx\n", vsize);
338 if (IS_ENABLED(CONFIG_KASAN) || __NO_KASLR_END_KERNEL > _REGION2_SIZE ||
339 (vsize > _REGION2_SIZE && kaslr_enabled())) {
340 asce_limit = _REGION1_SIZE;
341 if (__NO_KASLR_END_KERNEL > _REGION2_SIZE) {
342 rte_size = _REGION2_SIZE;
343 vsize = get_vmem_size(ident_map_size, vmemmap_size, vmalloc_size, _REGION2_SIZE);
344 } else {
345 rte_size = _REGION3_SIZE;
346 }
347 } else {
348 asce_limit = _REGION2_SIZE;
349 rte_size = _REGION3_SIZE;
350 }
351
352 /*
353 * Forcing modules and vmalloc area under the ultravisor
354 * secure storage limit, so that any vmalloc allocation
355 * we do could be used to back secure guest storage.
356 *
357 * Assume the secure storage limit always exceeds _REGION2_SIZE,
358 * otherwise asce_limit and rte_size would have been adjusted.
359 */
360 vmax = adjust_to_uv_max(asce_limit);
361 boot_debug("%d level paging 0x%016lx vmax\n", vmax == _REGION1_SIZE ? 4 : 3, vmax);
362 #ifdef CONFIG_KASAN
363 BUILD_BUG_ON(__NO_KASLR_END_KERNEL > KASAN_SHADOW_START);
364 boot_debug("KASAN shadow area: 0x%016lx-0x%016lx\n", KASAN_SHADOW_START, KASAN_SHADOW_END);
365 /* force vmalloc and modules below kasan shadow */
366 vmax = min(vmax, KASAN_SHADOW_START);
367 #endif
368 vsize = min(vsize, vmax);
369 if (kaslr_enabled()) {
370 unsigned long kernel_end, kaslr_len, slots, pos;
371
372 kaslr_len = max(KASLR_LEN, vmax - vsize);
373 slots = DIV_ROUND_UP(kaslr_len - kernel_size, THREAD_SIZE);
374 if (get_random(slots, &pos))
375 pos = 0;
376 kernel_end = vmax - pos * THREAD_SIZE;
377 kernel_start = round_down(kernel_end - kernel_size, THREAD_SIZE);
378 boot_debug("Randomization range: 0x%016lx-0x%016lx\n", vmax - kaslr_len, vmax);
379 boot_debug("kernel image: 0x%016lx-0x%016lx (kaslr)\n", kernel_start,
380 kernel_start + kernel_size);
381 } else if (vmax < __NO_KASLR_END_KERNEL || vsize > __NO_KASLR_END_KERNEL) {
382 kernel_start = round_down(vmax - kernel_size, THREAD_SIZE);
383 boot_debug("kernel image: 0x%016lx-0x%016lx (constrained)\n", kernel_start,
384 kernel_start + kernel_size);
385 } else {
386 kernel_start = __NO_KASLR_START_KERNEL;
387 boot_debug("kernel image: 0x%016lx-0x%016lx (nokaslr)\n", kernel_start,
388 kernel_start + kernel_size);
389 }
390 __kaslr_offset = kernel_start;
391 boot_debug("__kaslr_offset: 0x%016lx\n", __kaslr_offset);
392
393 MODULES_END = round_down(kernel_start, _SEGMENT_SIZE);
394 MODULES_VADDR = MODULES_END - MODULES_LEN;
395 VMALLOC_END = MODULES_VADDR;
396 if (IS_ENABLED(CONFIG_KMSAN))
397 VMALLOC_END -= MODULES_LEN * 2;
398 boot_debug("modules area: 0x%016lx-0x%016lx\n", MODULES_VADDR, MODULES_END);
399
400 /* allow vmalloc area to occupy up to about 1/2 of the rest virtual space left */
401 vsize = (VMALLOC_END - FIXMAP_SIZE) / 2;
402 vsize = round_down(vsize, _SEGMENT_SIZE);
403 vmalloc_size = min(vmalloc_size, vsize);
404 if (IS_ENABLED(CONFIG_KMSAN)) {
405 /* take 2/3 of vmalloc area for KMSAN shadow and origins */
406 vmalloc_size = round_down(vmalloc_size / 3, _SEGMENT_SIZE);
407 VMALLOC_END -= vmalloc_size * 2;
408 }
409 VMALLOC_START = VMALLOC_END - vmalloc_size;
410 boot_debug("vmalloc area: 0x%016lx-0x%016lx\n", VMALLOC_START, VMALLOC_END);
411
412 __memcpy_real_area = round_down(VMALLOC_START - MEMCPY_REAL_SIZE, PAGE_SIZE);
413 boot_debug("memcpy real area: 0x%016lx-0x%016lx\n", __memcpy_real_area,
414 __memcpy_real_area + MEMCPY_REAL_SIZE);
415 __abs_lowcore = round_down(__memcpy_real_area - ABS_LOWCORE_MAP_SIZE,
416 sizeof(struct lowcore));
417 boot_debug("abs lowcore: 0x%016lx-0x%016lx\n", __abs_lowcore,
418 __abs_lowcore + ABS_LOWCORE_MAP_SIZE);
419
420 /* split remaining virtual space between 1:1 mapping & vmemmap array */
421 pages = __abs_lowcore / (PAGE_SIZE + sizeof(struct page));
422 pages = SECTION_ALIGN_UP(pages);
423 /* keep vmemmap_start aligned to a top level region table entry */
424 vmemmap_start = round_down(__abs_lowcore - pages * sizeof(struct page), rte_size);
425 /* make sure identity map doesn't overlay with vmemmap */
426 ident_map_size = min(ident_map_size, vmemmap_start);
427 vmemmap_size = SECTION_ALIGN_UP(ident_map_size / PAGE_SIZE) * sizeof(struct page);
428 /* make sure vmemmap doesn't overlay with absolute lowcore area */
429 if (vmemmap_start + vmemmap_size > __abs_lowcore) {
430 vmemmap_size = SECTION_ALIGN_DOWN(ident_map_size / PAGE_SIZE) * sizeof(struct page);
431 ident_map_size = vmemmap_size / sizeof(struct page) * PAGE_SIZE;
432 }
433 vmemmap = (struct page *)vmemmap_start;
434 /* maximum address for which linear mapping could be created (DCSS, memory) */
435 BUILD_BUG_ON(MAX_DCSS_ADDR > (1UL << MAX_PHYSMEM_BITS));
436 max_mappable = max(ident_map_size, MAX_DCSS_ADDR);
437 max_mappable = min(max_mappable, vmemmap_start);
438 #ifdef CONFIG_RANDOMIZE_IDENTITY_BASE
439 __identity_base = round_down(vmemmap_start - max_mappable, rte_size);
440 #endif
441 boot_debug("identity map: 0x%016lx-0x%016lx\n", __identity_base,
442 __identity_base + ident_map_size);
443
444 return asce_limit;
445 }
446
447 /*
448 * This function clears the BSS section of the decompressed Linux kernel and NOT the decompressor's.
449 */
clear_bss_section(unsigned long kernel_start)450 static void clear_bss_section(unsigned long kernel_start)
451 {
452 memset((void *)kernel_start + vmlinux.image_size, 0, vmlinux.bss_size);
453 }
454
455 /*
456 * Set vmalloc area size to an 8th of (potential) physical memory
457 * size, unless size has been set by kernel command line parameter.
458 */
setup_vmalloc_size(void)459 static void setup_vmalloc_size(void)
460 {
461 unsigned long size;
462
463 if (vmalloc_size_set)
464 return;
465 size = round_up(ident_map_size / 8, _SEGMENT_SIZE);
466 vmalloc_size = max(size, vmalloc_size);
467 }
468
kaslr_adjust_vmlinux_info(long offset)469 static void kaslr_adjust_vmlinux_info(long offset)
470 {
471 vmlinux.bootdata_off += offset;
472 vmlinux.bootdata_preserved_off += offset;
473 vmlinux.got_start += offset;
474 vmlinux.got_end += offset;
475 vmlinux.init_mm_off += offset;
476 vmlinux.swapper_pg_dir_off += offset;
477 vmlinux.invalid_pg_dir_off += offset;
478 vmlinux.alt_instructions += offset;
479 vmlinux.alt_instructions_end += offset;
480 #ifdef CONFIG_KASAN
481 vmlinux.kasan_early_shadow_page_off += offset;
482 vmlinux.kasan_early_shadow_pte_off += offset;
483 vmlinux.kasan_early_shadow_pmd_off += offset;
484 vmlinux.kasan_early_shadow_pud_off += offset;
485 vmlinux.kasan_early_shadow_p4d_off += offset;
486 #endif
487 }
488
startup_kernel(void)489 void startup_kernel(void)
490 {
491 unsigned long vmlinux_size = vmlinux.image_size + vmlinux.bss_size;
492 unsigned long nokaslr_text_lma, text_lma = 0, amode31_lma = 0;
493 unsigned long kernel_size = TEXT_OFFSET + vmlinux_size;
494 unsigned long kaslr_large_page_offset;
495 unsigned long max_physmem_end;
496 unsigned long asce_limit;
497 unsigned long safe_addr;
498 psw_t psw;
499
500 setup_lpp();
501 store_ipl_parmblock();
502 uv_query_info();
503 setup_boot_command_line();
504 parse_boot_command_line();
505
506 /*
507 * Non-randomized kernel physical start address must be _SEGMENT_SIZE
508 * aligned (see blow).
509 */
510 nokaslr_text_lma = ALIGN(mem_safe_offset(), _SEGMENT_SIZE);
511 safe_addr = PAGE_ALIGN(nokaslr_text_lma + vmlinux_size);
512
513 /*
514 * Reserve decompressor memory together with decompression heap,
515 * buffer and memory which might be occupied by uncompressed kernel
516 * (if KASLR is off or failed).
517 */
518 physmem_reserve(RR_DECOMPRESSOR, 0, safe_addr);
519 if (IS_ENABLED(CONFIG_BLK_DEV_INITRD) && parmarea.initrd_size)
520 physmem_reserve(RR_INITRD, parmarea.initrd_start, parmarea.initrd_size);
521 oldmem_data.start = parmarea.oldmem_base;
522 oldmem_data.size = parmarea.oldmem_size;
523
524 read_ipl_report();
525 sclp_early_read_info();
526 sclp_early_detect_machine_features();
527 detect_facilities();
528 detect_diag9c();
529 detect_machine_type();
530 /* detect_diag288() needs machine type */
531 detect_diag288();
532 cmma_init();
533 sanitize_prot_virt_host();
534 max_physmem_end = detect_max_physmem_end();
535 setup_ident_map_size(max_physmem_end);
536 setup_vmalloc_size();
537 asce_limit = setup_kernel_memory_layout(kernel_size);
538 /* got final ident_map_size, physmem allocations could be performed now */
539 physmem_set_usable_limit(ident_map_size);
540 detect_physmem_online_ranges(max_physmem_end);
541 save_ipl_cert_comp_list();
542 rescue_initrd(safe_addr, ident_map_size);
543
544 /*
545 * __kaslr_offset_phys must be _SEGMENT_SIZE aligned, so the lower
546 * 20 bits (the offset within a large page) are zero. Copy the last
547 * 20 bits of __kaslr_offset, which is THREAD_SIZE aligned, to
548 * __kaslr_offset_phys.
549 *
550 * With this the last 20 bits of __kaslr_offset_phys and __kaslr_offset
551 * are identical, which is required to allow for large mappings of the
552 * kernel image.
553 */
554 kaslr_large_page_offset = __kaslr_offset & ~_SEGMENT_MASK;
555 if (kaslr_enabled()) {
556 unsigned long size = vmlinux_size + kaslr_large_page_offset;
557
558 text_lma = randomize_within_range(size, _SEGMENT_SIZE, TEXT_OFFSET, ident_map_size);
559 }
560 if (!text_lma)
561 text_lma = nokaslr_text_lma;
562 text_lma |= kaslr_large_page_offset;
563
564 /*
565 * [__kaslr_offset_phys..__kaslr_offset_phys + TEXT_OFFSET] region is
566 * never accessed via the kernel image mapping as per the linker script:
567 *
568 * . = TEXT_OFFSET;
569 *
570 * Therefore, this region could be used for something else and does
571 * not need to be reserved. See how it is skipped in setup_vmem().
572 */
573 __kaslr_offset_phys = text_lma - TEXT_OFFSET;
574 kaslr_adjust_vmlinux_info(__kaslr_offset_phys);
575 physmem_reserve(RR_VMLINUX, text_lma, vmlinux_size);
576 deploy_kernel((void *)text_lma);
577
578 /* vmlinux decompression is done, shrink reserved low memory */
579 physmem_reserve(RR_DECOMPRESSOR, 0, (unsigned long)_decompressor_end);
580
581 /*
582 * In case KASLR is enabled the randomized location of .amode31
583 * section might overlap with .vmlinux.relocs section. To avoid that
584 * the below randomize_within_range() could have been called with
585 * __vmlinux_relocs_64_end as the lower range address. However,
586 * .amode31 section is written to by the decompressed kernel - at
587 * that time the contents of .vmlinux.relocs is not needed anymore.
588 * Conversely, .vmlinux.relocs is read only by the decompressor, even
589 * before the kernel started. Therefore, in case the two sections
590 * overlap there is no risk of corrupting any data.
591 */
592 if (kaslr_enabled()) {
593 unsigned long amode31_min;
594
595 amode31_min = (unsigned long)_decompressor_end;
596 amode31_lma = randomize_within_range(vmlinux.amode31_size, PAGE_SIZE, amode31_min, SZ_2G);
597 }
598 if (!amode31_lma)
599 amode31_lma = text_lma - vmlinux.amode31_size;
600 physmem_reserve(RR_AMODE31, amode31_lma, vmlinux.amode31_size);
601
602 /*
603 * The order of the following operations is important:
604 *
605 * - kaslr_adjust_relocs() must follow clear_bss_section() to establish
606 * static memory references to data in .bss to be used by setup_vmem()
607 * (i.e init_mm.pgd)
608 *
609 * - setup_vmem() must follow kaslr_adjust_relocs() to be able using
610 * static memory references to data in .bss (i.e init_mm.pgd)
611 *
612 * - copy_bootdata() must follow setup_vmem() to propagate changes
613 * to bootdata made by setup_vmem()
614 */
615 clear_bss_section(text_lma);
616 kaslr_adjust_relocs(text_lma, text_lma + vmlinux.image_size,
617 __kaslr_offset, __kaslr_offset_phys);
618 kaslr_adjust_got(__kaslr_offset);
619 setup_vmem(__kaslr_offset, __kaslr_offset + kernel_size, asce_limit);
620 dump_physmem_reserved();
621 copy_bootdata();
622 __apply_alternatives((struct alt_instr *)_vmlinux_info.alt_instructions,
623 (struct alt_instr *)_vmlinux_info.alt_instructions_end,
624 ALT_CTX_EARLY);
625
626 /*
627 * Save KASLR offset for early dumps, before vmcore_info is set.
628 * Mark as uneven to distinguish from real vmcore_info pointer.
629 */
630 get_lowcore()->vmcore_info = __kaslr_offset_phys ? __kaslr_offset_phys | 0x1UL : 0;
631
632 /*
633 * Jump to the decompressed kernel entry point and switch DAT mode on.
634 */
635 psw.addr = __kaslr_offset + vmlinux.entry;
636 psw.mask = PSW_KERNEL_BITS;
637 boot_debug("Starting kernel at: 0x%016lx\n", psw.addr);
638 jump_to_kernel(&psw);
639 }
640