1/*
  2 * handle transition of Linux booting another kernel
  3 * Copyright (C) 2002-2005 Eric Biederman  <ebiederm@xmission.com>
  4 *
  5 * This source code is licensed under the GNU General Public License,
  6 * Version 2.  See the file COPYING for more details.
  7 */
  8
  9#include <linux/mm.h>
 10#include <linux/kexec.h>
 11#include <linux/delay.h>
 
 12#include <linux/numa.h>
 13#include <linux/ftrace.h>
 14#include <linux/suspend.h>
 15#include <linux/gfp.h>
 16#include <linux/io.h>
 17
 18#include <asm/pgtable.h>
 19#include <asm/pgalloc.h>
 20#include <asm/tlbflush.h>
 21#include <asm/mmu_context.h>
 22#include <asm/apic.h>
 23#include <asm/io_apic.h>
 24#include <asm/cpufeature.h>
 25#include <asm/desc.h>
 26#include <asm/set_memory.h>
 27#include <asm/debugreg.h>
 28
 
 
 
 
 
 
 
 
 
 
 
 
 29static void set_gdt(void *newgdt, __u16 limit)
 30{
 31	struct desc_ptr curgdt;
 32
 33	/* ia32 supports unaligned loads & stores */
 34	curgdt.size    = limit;
 35	curgdt.address = (unsigned long)newgdt;
 36
 37	load_gdt(&curgdt);
 38}
 39
 40static void load_segments(void)
 41{
 42#define __STR(X) #X
 43#define STR(X) __STR(X)
 44
 45	__asm__ __volatile__ (
 46		"\tljmp $"STR(__KERNEL_CS)",$1f\n"
 47		"\t1:\n"
 48		"\tmovl $"STR(__KERNEL_DS)",%%eax\n"
 49		"\tmovl %%eax,%%ds\n"
 50		"\tmovl %%eax,%%es\n"
 
 
 51		"\tmovl %%eax,%%ss\n"
 52		: : : "eax", "memory");
 53#undef STR
 54#undef __STR
 55}
 56
 57static void machine_kexec_free_page_tables(struct kimage *image)
 58{
 59	free_page((unsigned long)image->arch.pgd);
 60	image->arch.pgd = NULL;
 61#ifdef CONFIG_X86_PAE
 62	free_page((unsigned long)image->arch.pmd0);
 63	image->arch.pmd0 = NULL;
 64	free_page((unsigned long)image->arch.pmd1);
 65	image->arch.pmd1 = NULL;
 66#endif
 67	free_page((unsigned long)image->arch.pte0);
 68	image->arch.pte0 = NULL;
 69	free_page((unsigned long)image->arch.pte1);
 70	image->arch.pte1 = NULL;
 71}
 72
 73static int machine_kexec_alloc_page_tables(struct kimage *image)
 74{
 75	image->arch.pgd = (pgd_t *)get_zeroed_page(GFP_KERNEL);
 76#ifdef CONFIG_X86_PAE
 77	image->arch.pmd0 = (pmd_t *)get_zeroed_page(GFP_KERNEL);
 78	image->arch.pmd1 = (pmd_t *)get_zeroed_page(GFP_KERNEL);
 79#endif
 80	image->arch.pte0 = (pte_t *)get_zeroed_page(GFP_KERNEL);
 81	image->arch.pte1 = (pte_t *)get_zeroed_page(GFP_KERNEL);
 82	if (!image->arch.pgd ||
 83#ifdef CONFIG_X86_PAE
 84	    !image->arch.pmd0 || !image->arch.pmd1 ||
 85#endif
 86	    !image->arch.pte0 || !image->arch.pte1) {
 
 87		return -ENOMEM;
 88	}
 89	return 0;
 90}
 91
 92static void machine_kexec_page_table_set_one(
 93	pgd_t *pgd, pmd_t *pmd, pte_t *pte,
 94	unsigned long vaddr, unsigned long paddr)
 95{
 96	p4d_t *p4d;
 97	pud_t *pud;
 98
 99	pgd += pgd_index(vaddr);
100#ifdef CONFIG_X86_PAE
101	if (!(pgd_val(*pgd) & _PAGE_PRESENT))
102		set_pgd(pgd, __pgd(__pa(pmd) | _PAGE_PRESENT));
103#endif
104	p4d = p4d_offset(pgd, vaddr);
105	pud = pud_offset(p4d, vaddr);
106	pmd = pmd_offset(pud, vaddr);
107	if (!(pmd_val(*pmd) & _PAGE_PRESENT))
108		set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
109	pte = pte_offset_kernel(pmd, vaddr);
110	set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));
111}
112
113static void machine_kexec_prepare_page_tables(struct kimage *image)
114{
115	void *control_page;
116	pmd_t *pmd = NULL;
117
118	control_page = page_address(image->control_code_page);
119#ifdef CONFIG_X86_PAE
120	pmd = image->arch.pmd0;
121#endif
122	machine_kexec_page_table_set_one(
123		image->arch.pgd, pmd, image->arch.pte0,
124		(unsigned long)control_page, __pa(control_page));
125#ifdef CONFIG_X86_PAE
126	pmd = image->arch.pmd1;
127#endif
128	machine_kexec_page_table_set_one(
129		image->arch.pgd, pmd, image->arch.pte1,
130		__pa(control_page), __pa(control_page));
131}
132
133/*
134 * A architecture hook called to validate the
135 * proposed image and prepare the control pages
136 * as needed.  The pages for KEXEC_CONTROL_PAGE_SIZE
137 * have been allocated, but the segments have yet
138 * been copied into the kernel.
139 *
140 * Do what every setup is needed on image and the
141 * reboot code buffer to allow us to avoid allocations
142 * later.
143 *
144 * - Make control page executable.
145 * - Allocate page tables
146 * - Setup page tables
147 */
148int machine_kexec_prepare(struct kimage *image)
149{
150	int error;
151
152	set_pages_x(image->control_code_page, 1);
153	error = machine_kexec_alloc_page_tables(image);
154	if (error)
155		return error;
156	machine_kexec_prepare_page_tables(image);
157	return 0;
158}
159
160/*
161 * Undo anything leftover by machine_kexec_prepare
162 * when an image is freed.
163 */
164void machine_kexec_cleanup(struct kimage *image)
165{
166	set_pages_nx(image->control_code_page, 1);
167	machine_kexec_free_page_tables(image);
168}
169
170/*
171 * Do not allocate memory (or fail in any way) in machine_kexec().
172 * We are past the point of no return, committed to rebooting now.
173 */
174void machine_kexec(struct kimage *image)
175{
176	unsigned long page_list[PAGES_NR];
177	void *control_page;
178	int save_ftrace_enabled;
179	asmlinkage unsigned long
180		(*relocate_kernel_ptr)(unsigned long indirection_page,
181				       unsigned long control_page,
182				       unsigned long start_address,
183				       unsigned int has_pae,
184				       unsigned int preserve_context);
185
186#ifdef CONFIG_KEXEC_JUMP
187	if (image->preserve_context)
188		save_processor_state();
189#endif
190
191	save_ftrace_enabled = __ftrace_enabled_save();
192
193	/* Interrupts aren't acceptable while we reboot */
194	local_irq_disable();
195	hw_breakpoint_disable();
196
197	if (image->preserve_context) {
198#ifdef CONFIG_X86_IO_APIC
199		/*
200		 * We need to put APICs in legacy mode so that we can
201		 * get timer interrupts in second kernel. kexec/kdump
202		 * paths already have calls to restore_boot_irq_mode()
203		 * in one form or other. kexec jump path also need one.
 
204		 */
205		clear_IO_APIC();
206		restore_boot_irq_mode();
207#endif
208	}
209
210	control_page = page_address(image->control_code_page);
211	memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
212
213	relocate_kernel_ptr = control_page;
214	page_list[PA_CONTROL_PAGE] = __pa(control_page);
215	page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
216	page_list[PA_PGD] = __pa(image->arch.pgd);
217
218	if (image->type == KEXEC_TYPE_DEFAULT)
219		page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
220						<< PAGE_SHIFT);
221
222	/*
223	 * The segment registers are funny things, they have both a
224	 * visible and an invisible part.  Whenever the visible part is
225	 * set to a specific selector, the invisible part is loaded
226	 * with from a table in memory.  At no other time is the
227	 * descriptor table in memory accessed.
228	 *
229	 * I take advantage of this here by force loading the
230	 * segments, before I zap the gdt with an invalid value.
231	 */
232	load_segments();
233	/*
234	 * The gdt & idt are now invalid.
235	 * If you want to load them you must set up your own idt & gdt.
236	 */
237	idt_invalidate(phys_to_virt(0));
238	set_gdt(phys_to_virt(0), 0);
 
239
240	/* now call it */
241	image->start = relocate_kernel_ptr((unsigned long)image->head,
242					   (unsigned long)page_list,
243					   image->start,
244					   boot_cpu_has(X86_FEATURE_PAE),
245					   image->preserve_context);
246
247#ifdef CONFIG_KEXEC_JUMP
248	if (image->preserve_context)
249		restore_processor_state();
250#endif
251
252	__ftrace_enabled_restore(save_ftrace_enabled);
253}
254
255void arch_crash_save_vmcoreinfo(void)
256{
257#ifdef CONFIG_NUMA
258	VMCOREINFO_SYMBOL(node_data);
259	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
260#endif
261#ifdef CONFIG_X86_PAE
262	VMCOREINFO_CONFIG(X86_PAE);
263#endif
264}
265

  1/*
  2 * handle transition of Linux booting another kernel
  3 * Copyright (C) 2002-2005 Eric Biederman  <ebiederm@xmission.com>
  4 *
  5 * This source code is licensed under the GNU General Public License,
  6 * Version 2.  See the file COPYING for more details.
  7 */
  8
  9#include <linux/mm.h>
 10#include <linux/kexec.h>
 11#include <linux/delay.h>
 12#include <linux/init.h>
 13#include <linux/numa.h>
 14#include <linux/ftrace.h>
 15#include <linux/suspend.h>
 16#include <linux/gfp.h>
 17#include <linux/io.h>
 18
 19#include <asm/pgtable.h>
 20#include <asm/pgalloc.h>
 21#include <asm/tlbflush.h>
 22#include <asm/mmu_context.h>
 23#include <asm/apic.h>
 
 24#include <asm/cpufeature.h>
 25#include <asm/desc.h>
 26#include <asm/cacheflush.h>
 27#include <asm/debugreg.h>
 28
 29static void set_idt(void *newidt, __u16 limit)
 30{
 31	struct desc_ptr curidt;
 32
 33	/* ia32 supports unaliged loads & stores */
 34	curidt.size    = limit;
 35	curidt.address = (unsigned long)newidt;
 36
 37	load_idt(&curidt);
 38}
 39
 40
 41static void set_gdt(void *newgdt, __u16 limit)
 42{
 43	struct desc_ptr curgdt;
 44
 45	/* ia32 supports unaligned loads & stores */
 46	curgdt.size    = limit;
 47	curgdt.address = (unsigned long)newgdt;
 48
 49	load_gdt(&curgdt);
 50}
 51
 52static void load_segments(void)
 53{
 54#define __STR(X) #X
 55#define STR(X) __STR(X)
 56
 57	__asm__ __volatile__ (
 58		"\tljmp $"STR(__KERNEL_CS)",$1f\n"
 59		"\t1:\n"
 60		"\tmovl $"STR(__KERNEL_DS)",%%eax\n"
 61		"\tmovl %%eax,%%ds\n"
 62		"\tmovl %%eax,%%es\n"
 63		"\tmovl %%eax,%%fs\n"
 64		"\tmovl %%eax,%%gs\n"
 65		"\tmovl %%eax,%%ss\n"
 66		: : : "eax", "memory");
 67#undef STR
 68#undef __STR
 69}
 70
 71static void machine_kexec_free_page_tables(struct kimage *image)
 72{
 73	free_page((unsigned long)image->arch.pgd);
 
 74#ifdef CONFIG_X86_PAE
 75	free_page((unsigned long)image->arch.pmd0);
 
 76	free_page((unsigned long)image->arch.pmd1);
 
 77#endif
 78	free_page((unsigned long)image->arch.pte0);
 
 79	free_page((unsigned long)image->arch.pte1);
 
 80}
 81
 82static int machine_kexec_alloc_page_tables(struct kimage *image)
 83{
 84	image->arch.pgd = (pgd_t *)get_zeroed_page(GFP_KERNEL);
 85#ifdef CONFIG_X86_PAE
 86	image->arch.pmd0 = (pmd_t *)get_zeroed_page(GFP_KERNEL);
 87	image->arch.pmd1 = (pmd_t *)get_zeroed_page(GFP_KERNEL);
 88#endif
 89	image->arch.pte0 = (pte_t *)get_zeroed_page(GFP_KERNEL);
 90	image->arch.pte1 = (pte_t *)get_zeroed_page(GFP_KERNEL);
 91	if (!image->arch.pgd ||
 92#ifdef CONFIG_X86_PAE
 93	    !image->arch.pmd0 || !image->arch.pmd1 ||
 94#endif
 95	    !image->arch.pte0 || !image->arch.pte1) {
 96		machine_kexec_free_page_tables(image);
 97		return -ENOMEM;
 98	}
 99	return 0;
100}
101
102static void machine_kexec_page_table_set_one(
103	pgd_t *pgd, pmd_t *pmd, pte_t *pte,
104	unsigned long vaddr, unsigned long paddr)
105{
 
106	pud_t *pud;
107
108	pgd += pgd_index(vaddr);
109#ifdef CONFIG_X86_PAE
110	if (!(pgd_val(*pgd) & _PAGE_PRESENT))
111		set_pgd(pgd, __pgd(__pa(pmd) | _PAGE_PRESENT));
112#endif
113	pud = pud_offset(pgd, vaddr);
 
114	pmd = pmd_offset(pud, vaddr);
115	if (!(pmd_val(*pmd) & _PAGE_PRESENT))
116		set_pmd(pmd, __pmd(__pa(pte) | _PAGE_TABLE));
117	pte = pte_offset_kernel(pmd, vaddr);
118	set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, PAGE_KERNEL_EXEC));
119}
120
121static void machine_kexec_prepare_page_tables(struct kimage *image)
122{
123	void *control_page;
124	pmd_t *pmd = NULL;
125
126	control_page = page_address(image->control_code_page);
127#ifdef CONFIG_X86_PAE
128	pmd = image->arch.pmd0;
129#endif
130	machine_kexec_page_table_set_one(
131		image->arch.pgd, pmd, image->arch.pte0,
132		(unsigned long)control_page, __pa(control_page));
133#ifdef CONFIG_X86_PAE
134	pmd = image->arch.pmd1;
135#endif
136	machine_kexec_page_table_set_one(
137		image->arch.pgd, pmd, image->arch.pte1,
138		__pa(control_page), __pa(control_page));
139}
140
141/*
142 * A architecture hook called to validate the
143 * proposed image and prepare the control pages
144 * as needed.  The pages for KEXEC_CONTROL_PAGE_SIZE
145 * have been allocated, but the segments have yet
146 * been copied into the kernel.
147 *
148 * Do what every setup is needed on image and the
149 * reboot code buffer to allow us to avoid allocations
150 * later.
151 *
152 * - Make control page executable.
153 * - Allocate page tables
154 * - Setup page tables
155 */
156int machine_kexec_prepare(struct kimage *image)
157{
158	int error;
159
160	set_pages_x(image->control_code_page, 1);
161	error = machine_kexec_alloc_page_tables(image);
162	if (error)
163		return error;
164	machine_kexec_prepare_page_tables(image);
165	return 0;
166}
167
168/*
169 * Undo anything leftover by machine_kexec_prepare
170 * when an image is freed.
171 */
172void machine_kexec_cleanup(struct kimage *image)
173{
174	set_pages_nx(image->control_code_page, 1);
175	machine_kexec_free_page_tables(image);
176}
177
178/*
179 * Do not allocate memory (or fail in any way) in machine_kexec().
180 * We are past the point of no return, committed to rebooting now.
181 */
182void machine_kexec(struct kimage *image)
183{
184	unsigned long page_list[PAGES_NR];
185	void *control_page;
186	int save_ftrace_enabled;
187	asmlinkage unsigned long
188		(*relocate_kernel_ptr)(unsigned long indirection_page,
189				       unsigned long control_page,
190				       unsigned long start_address,
191				       unsigned int has_pae,
192				       unsigned int preserve_context);
193
194#ifdef CONFIG_KEXEC_JUMP
195	if (image->preserve_context)
196		save_processor_state();
197#endif
198
199	save_ftrace_enabled = __ftrace_enabled_save();
200
201	/* Interrupts aren't acceptable while we reboot */
202	local_irq_disable();
203	hw_breakpoint_disable();
204
205	if (image->preserve_context) {
206#ifdef CONFIG_X86_IO_APIC
207		/*
208		 * We need to put APICs in legacy mode so that we can
209		 * get timer interrupts in second kernel. kexec/kdump
210		 * paths already have calls to disable_IO_APIC() in
211		 * one form or other. kexec jump path also need
212		 * one.
213		 */
214		disable_IO_APIC();
 
215#endif
216	}
217
218	control_page = page_address(image->control_code_page);
219	memcpy(control_page, relocate_kernel, KEXEC_CONTROL_CODE_MAX_SIZE);
220
221	relocate_kernel_ptr = control_page;
222	page_list[PA_CONTROL_PAGE] = __pa(control_page);
223	page_list[VA_CONTROL_PAGE] = (unsigned long)control_page;
224	page_list[PA_PGD] = __pa(image->arch.pgd);
225
226	if (image->type == KEXEC_TYPE_DEFAULT)
227		page_list[PA_SWAP_PAGE] = (page_to_pfn(image->swap_page)
228						<< PAGE_SHIFT);
229
230	/*
231	 * The segment registers are funny things, they have both a
232	 * visible and an invisible part.  Whenever the visible part is
233	 * set to a specific selector, the invisible part is loaded
234	 * with from a table in memory.  At no other time is the
235	 * descriptor table in memory accessed.
236	 *
237	 * I take advantage of this here by force loading the
238	 * segments, before I zap the gdt with an invalid value.
239	 */
240	load_segments();
241	/*
242	 * The gdt & idt are now invalid.
243	 * If you want to load them you must set up your own idt & gdt.
244	 */
 
245	set_gdt(phys_to_virt(0), 0);
246	set_idt(phys_to_virt(0), 0);
247
248	/* now call it */
249	image->start = relocate_kernel_ptr((unsigned long)image->head,
250					   (unsigned long)page_list,
251					   image->start, cpu_has_pae,
 
252					   image->preserve_context);
253
254#ifdef CONFIG_KEXEC_JUMP
255	if (image->preserve_context)
256		restore_processor_state();
257#endif
258
259	__ftrace_enabled_restore(save_ftrace_enabled);
260}
261
262void arch_crash_save_vmcoreinfo(void)
263{
264#ifdef CONFIG_NUMA
265	VMCOREINFO_SYMBOL(node_data);
266	VMCOREINFO_LENGTH(node_data, MAX_NUMNODES);
267#endif
268#ifdef CONFIG_X86_PAE
269	VMCOREINFO_CONFIG(X86_PAE);
270#endif
271}
272