[linux-2.6-block.git] / arch / s390 / kernel / crash_dump.c

/*
 * S390 kdump implementation
 *
 * Copyright IBM Corp. 2011
 * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
 */

#include <linux/crash_dump.h>
#include <asm/lowcore.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/slab.h>
#include <linux/bootmem.h>
#include <linux/elf.h>
#include <asm/ipl.h>

#define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))

/*
 * Copy one page from "oldmem"
 *
 * For the kdump reserved memory this functions performs a swap operation:
 *  - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
 *  - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
 */
ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
			 size_t csize, unsigned long offset, int userbuf)
{
	unsigned long src;

	if (!csize)
		return 0;

	src = (pfn << PAGE_SHIFT) + offset;
	if (src < OLDMEM_SIZE)
		src += OLDMEM_BASE;
	else if (src > OLDMEM_BASE &&
		 src < OLDMEM_BASE + OLDMEM_SIZE)
		src -= OLDMEM_BASE;
	if (userbuf)
		copy_to_user_real((void __force __user *) buf, (void *) src,
				  csize);
	else
		memcpy_real(buf, (void *) src, csize);
	return csize;
}

/*
 * Copy memory from old kernel
 */
static int copy_from_oldmem(void *dest, void *src, size_t count)
{
	unsigned long copied = 0;
	int rc;

	if ((unsigned long) src < OLDMEM_SIZE) {
		copied = min(count, OLDMEM_SIZE - (unsigned long) src);
		rc = memcpy_real(dest, src + OLDMEM_BASE, copied);
		if (rc)
			return rc;
	}
	return memcpy_real(dest + copied, src + copied, count - copied);
}

/*
 * Alloc memory and panic in case of ENOMEM
 */
static void *kzalloc_panic(int len)
{
	void *rc;

	rc = kzalloc(len, GFP_KERNEL);
	if (!rc)
		panic("s390 kdump kzalloc (%d) failed", len);
	return rc;
}

/*
 * Get memory layout and create hole for oldmem
 */
static struct mem_chunk *get_memory_layout(void)
{
	struct mem_chunk *chunk_array;

	chunk_array = kzalloc_panic(MEMORY_CHUNKS * sizeof(struct mem_chunk));
	detect_memory_layout(chunk_array);
	create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE, CHUNK_CRASHK);
	return chunk_array;
}

/*
 * Initialize ELF note
 */
static void *nt_init(void *buf, Elf64_Word type, void *desc, int d_len,
		     const char *name)
{
	Elf64_Nhdr *note;
	u64 len;

	note = (Elf64_Nhdr *)buf;
	note->n_namesz = strlen(name) + 1;
	note->n_descsz = d_len;
	note->n_type = type;
	len = sizeof(Elf64_Nhdr);

	memcpy(buf + len, name, note->n_namesz);
	len = roundup(len + note->n_namesz, 4);

	memcpy(buf + len, desc, note->n_descsz);
	len = roundup(len + note->n_descsz, 4);

	return PTR_ADD(buf, len);
}

/*
 * Initialize prstatus note
 */
static void *nt_prstatus(void *ptr, struct save_area *sa)
{
	struct elf_prstatus nt_prstatus;
	static int cpu_nr = 1;

	memset(&nt_prstatus, 0, sizeof(nt_prstatus));
	memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));
	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
	memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));
	nt_prstatus.pr_pid = cpu_nr;
	cpu_nr++;

	return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),
			 "CORE");
}

/*
 * Initialize fpregset (floating point) note
 */
static void *nt_fpregset(void *ptr, struct save_area *sa)
{
	elf_fpregset_t nt_fpregset;

	memset(&nt_fpregset, 0, sizeof(nt_fpregset));
	memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));
	memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));

	return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),
		       "CORE");
}

/*
 * Initialize timer note
 */
static void *nt_s390_timer(void *ptr, struct save_area *sa)
{
	return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
			 KEXEC_CORE_NOTE_NAME);
}

/*
 * Initialize TOD clock comparator note
 */
static void *nt_s390_tod_cmp(void *ptr, struct save_area *sa)
{
	return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
		       sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);
}

/*
 * Initialize TOD programmable register note
 */
static void *nt_s390_tod_preg(void *ptr, struct save_area *sa)
{
	return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
		       sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);
}

/*
 * Initialize control register note
 */
static void *nt_s390_ctrs(void *ptr, struct save_area *sa)
{
	return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
		       sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);
}

/*
 * Initialize prefix register note
 */
static void *nt_s390_prefix(void *ptr, struct save_area *sa)
{
	return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
			 sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);
}

/*
 * Fill ELF notes for one CPU with save area registers
 */
void *fill_cpu_elf_notes(void *ptr, struct save_area *sa)
{
	ptr = nt_prstatus(ptr, sa);
	ptr = nt_fpregset(ptr, sa);
	ptr = nt_s390_timer(ptr, sa);
	ptr = nt_s390_tod_cmp(ptr, sa);
	ptr = nt_s390_tod_preg(ptr, sa);
	ptr = nt_s390_ctrs(ptr, sa);
	ptr = nt_s390_prefix(ptr, sa);
	return ptr;
}

/*
 * Initialize prpsinfo note (new kernel)
 */
static void *nt_prpsinfo(void *ptr)
{
	struct elf_prpsinfo prpsinfo;

	memset(&prpsinfo, 0, sizeof(prpsinfo));
	prpsinfo.pr_sname = 'R';
	strcpy(prpsinfo.pr_fname, "vmlinux");
	return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),
		       KEXEC_CORE_NOTE_NAME);
}

/*
 * Initialize vmcoreinfo note (new kernel)
 */
static void *nt_vmcoreinfo(void *ptr)
{
	char nt_name[11], *vmcoreinfo;
	Elf64_Nhdr note;
	void *addr;

	if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
		return ptr;
	memset(nt_name, 0, sizeof(nt_name));
	if (copy_from_oldmem(&note, addr, sizeof(note)))
		return ptr;
	if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
		return ptr;
	if (strcmp(nt_name, "VMCOREINFO") != 0)
		return ptr;
	vmcoreinfo = kzalloc_panic(note.n_descsz + 1);
	if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
		return ptr;
	vmcoreinfo[note.n_descsz + 1] = 0;
	return nt_init(ptr, 0, vmcoreinfo, note.n_descsz, "VMCOREINFO");
}

/*
 * Initialize ELF header (new kernel)
 */
static void *ehdr_init(Elf64_Ehdr *ehdr, int mem_chunk_cnt)
{
	memset(ehdr, 0, sizeof(*ehdr));
	memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
	ehdr->e_ident[EI_CLASS] = ELFCLASS64;
	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
	memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
	ehdr->e_type = ET_CORE;
	ehdr->e_machine = EM_S390;
	ehdr->e_version = EV_CURRENT;
	ehdr->e_phoff = sizeof(Elf64_Ehdr);
	ehdr->e_ehsize = sizeof(Elf64_Ehdr);
	ehdr->e_phentsize = sizeof(Elf64_Phdr);
	ehdr->e_phnum = mem_chunk_cnt + 1;
	return ehdr + 1;
}

/*
 * Return CPU count for ELF header (new kernel)
 */
static int get_cpu_cnt(void)
{
	int i, cpus = 0;

	for (i = 0; zfcpdump_save_areas[i]; i++) {
		if (zfcpdump_save_areas[i]->pref_reg == 0)
			continue;
		cpus++;
	}
	return cpus;
}

/*
 * Return memory chunk count for ELF header (new kernel)
 */
static int get_mem_chunk_cnt(void)
{
	struct mem_chunk *chunk_array, *mem_chunk;
	int i, cnt = 0;

	chunk_array = get_memory_layout();
	for (i = 0; i < MEMORY_CHUNKS; i++) {
		mem_chunk = &chunk_array[i];
		if (chunk_array[i].type != CHUNK_READ_WRITE &&
		    chunk_array[i].type != CHUNK_READ_ONLY)
			continue;
		if (mem_chunk->size == 0)
			continue;
		cnt++;
	}
	kfree(chunk_array);
	return cnt;
}

/*
 * Relocate pointer in order to allow vmcore code access the data
 */
static inline unsigned long relocate(unsigned long addr)
{
	return OLDMEM_BASE + addr;
}

/*
 * Initialize ELF loads (new kernel)
 */
static int loads_init(Elf64_Phdr *phdr, u64 loads_offset)
{
	struct mem_chunk *chunk_array, *mem_chunk;
	int i;

	chunk_array = get_memory_layout();
	for (i = 0; i < MEMORY_CHUNKS; i++) {
		mem_chunk = &chunk_array[i];
		if (mem_chunk->size == 0)
			break;
		if (chunk_array[i].type != CHUNK_READ_WRITE &&
		    chunk_array[i].type != CHUNK_READ_ONLY)
			continue;
		else
			phdr->p_filesz = mem_chunk->size;
		phdr->p_type = PT_LOAD;
		phdr->p_offset = mem_chunk->addr;
		phdr->p_vaddr = mem_chunk->addr;
		phdr->p_paddr = mem_chunk->addr;
		phdr->p_memsz = mem_chunk->size;
		phdr->p_flags = PF_R | PF_W | PF_X;
		phdr->p_align = PAGE_SIZE;
		phdr++;
	}
	kfree(chunk_array);
	return i;
}

/*
 * Initialize notes (new kernel)
 */
static void *notes_init(Elf64_Phdr *phdr, void *ptr, u64 notes_offset)
{
	struct save_area *sa;
	void *ptr_start = ptr;
	int i;

	ptr = nt_prpsinfo(ptr);

	for (i = 0; zfcpdump_save_areas[i]; i++) {
		sa = zfcpdump_save_areas[i];
		if (sa->pref_reg == 0)
			continue;
		ptr = fill_cpu_elf_notes(ptr, sa);
	}
	ptr = nt_vmcoreinfo(ptr);
	memset(phdr, 0, sizeof(*phdr));
	phdr->p_type = PT_NOTE;
	phdr->p_offset = relocate(notes_offset);
	phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
	phdr->p_memsz = phdr->p_filesz;
	return ptr;
}

/*
 * Create ELF core header (new kernel)
 */
static void s390_elf_corehdr_create(char **elfcorebuf, size_t *elfcorebuf_sz)
{
	Elf64_Phdr *phdr_notes, *phdr_loads;
	int mem_chunk_cnt;
	void *ptr, *hdr;
	u32 alloc_size;
	u64 hdr_off;

	mem_chunk_cnt = get_mem_chunk_cnt();

	alloc_size = 0x1000 + get_cpu_cnt() * 0x300 +
		mem_chunk_cnt * sizeof(Elf64_Phdr);
	hdr = kzalloc_panic(alloc_size);
	/* Init elf header */
	ptr = ehdr_init(hdr, mem_chunk_cnt);
	/* Init program headers */
	phdr_notes = ptr;
	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
	phdr_loads = ptr;
	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
	/* Init notes */
	hdr_off = PTR_DIFF(ptr, hdr);
	ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
	/* Init loads */
	hdr_off = PTR_DIFF(ptr, hdr);
	loads_init(phdr_loads, ((unsigned long) hdr) + hdr_off);
	*elfcorebuf_sz = hdr_off;
	*elfcorebuf = (void *) relocate((unsigned long) hdr);
	BUG_ON(*elfcorebuf_sz > alloc_size);
}

/*
 * Create kdump ELF core header in new kernel, if it has not been passed via
 * the "elfcorehdr" kernel parameter
 */
static int setup_kdump_elfcorehdr(void)
{
	size_t elfcorebuf_sz;
	char *elfcorebuf;

	if (!OLDMEM_BASE || is_kdump_kernel())
		return -EINVAL;
	s390_elf_corehdr_create(&elfcorebuf, &elfcorebuf_sz);
	elfcorehdr_addr = (unsigned long long) elfcorebuf;
	elfcorehdr_size = elfcorebuf_sz;
	return 0;
}

subsys_initcall(setup_kdump_elfcorehdr);
Commit	Line	Data
60a0c68d MH	1	/*
	2	* S390 kdump implementation
	3	*
	4	* Copyright IBM Corp. 2011
	5	* Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
	6	*/
	7
	8	#include <linux/crash_dump.h>
	9	#include <asm/lowcore.h>
	10	#include <linux/kernel.h>
	11	#include <linux/module.h>
	12	#include <linux/gfp.h>
	13	#include <linux/slab.h>
60a0c68d MH	14	#include <linux/bootmem.h>
	15	#include <linux/elf.h>
	16	#include <asm/ipl.h>
	17
	18	#define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
	19	#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
	20	#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
	21
	22	/*
	23	* Copy one page from "oldmem"
	24	*
	25	* For the kdump reserved memory this functions performs a swap operation:
	26	* - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
	27	* - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
	28	*/
	29	ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
	30	size_t csize, unsigned long offset, int userbuf)
	31	{
	32	unsigned long src;
60a0c68d MH	33
	34	if (!csize)
	35	return 0;
	36
	37	src = (pfn << PAGE_SHIFT) + offset;
	38	if (src < OLDMEM_SIZE)
	39	src += OLDMEM_BASE;
	40	else if (src > OLDMEM_BASE &&
	41	src < OLDMEM_BASE + OLDMEM_SIZE)
	42	src -= OLDMEM_BASE;
	43	if (userbuf)
07ea815b MH	44	copy_to_user_real((void __force __user ) buf, (void ) src,
07ea815b MH	45	csize);
60a0c68d	46	else
07ea815b MH	47	memcpy_real(buf, (void *) src, csize);
07ea815b MH	48	return csize;
60a0c68d MH	49	}
	50
	51	/*
	52	* Copy memory from old kernel
	53	*/
	54	static int copy_from_oldmem(void dest, void src, size_t count)
	55	{
	56	unsigned long copied = 0;
	57	int rc;
	58
	59	if ((unsigned long) src < OLDMEM_SIZE) {
	60	copied = min(count, OLDMEM_SIZE - (unsigned long) src);
	61	rc = memcpy_real(dest, src + OLDMEM_BASE, copied);
	62	if (rc)
	63	return rc;
	64	}
	65	return memcpy_real(dest + copied, src + copied, count - copied);
	66	}
	67
	68	/*
	69	* Alloc memory and panic in case of ENOMEM
	70	*/
	71	static void *kzalloc_panic(int len)
	72	{
	73	void *rc;
	74
	75	rc = kzalloc(len, GFP_KERNEL);
	76	if (!rc)
	77	panic("s390 kdump kzalloc (%d) failed", len);
	78	return rc;
	79	}
	80
	81	/*
	82	* Get memory layout and create hole for oldmem
	83	*/
	84	static struct mem_chunk *get_memory_layout(void)
	85	{
	86	struct mem_chunk *chunk_array;
	87
	88	chunk_array = kzalloc_panic(MEMORY_CHUNKS * sizeof(struct mem_chunk));
	89	detect_memory_layout(chunk_array);
	90	create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE, CHUNK_CRASHK);
	91	return chunk_array;
	92	}
	93
	94	/*
	95	* Initialize ELF note
	96	*/
	97	static void nt_init(void buf, Elf64_Word type, void *desc, int d_len,
	98	const char *name)
	99	{
	100	Elf64_Nhdr *note;
	101	u64 len;
	102
	103	note = (Elf64_Nhdr *)buf;
	104	note->n_namesz = strlen(name) + 1;
	105	note->n_descsz = d_len;
	106	note->n_type = type;
	107	len = sizeof(Elf64_Nhdr);
	108
	109	memcpy(buf + len, name, note->n_namesz);
	110	len = roundup(len + note->n_namesz, 4);
	111
	112	memcpy(buf + len, desc, note->n_descsz);
113	len = roundup(len + note->n_descsz, 4);
114
115	return PTR_ADD(buf, len);
116	}
117
118	/*
119	* Initialize prstatus note
120	*/
121	static void nt_prstatus(void ptr, struct save_area *sa)
122	{
123	struct elf_prstatus nt_prstatus;
124	static int cpu_nr = 1;
125
126	memset(&nt_prstatus, 0, sizeof(nt_prstatus));
127	memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));
128	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
129	memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));
130	nt_prstatus.pr_pid = cpu_nr;
131	cpu_nr++;
132
133	return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),
134	"CORE");
135	}
136
137	/*
138	* Initialize fpregset (floating point) note
139	*/
140	static void nt_fpregset(void ptr, struct save_area *sa)
141	{
142	elf_fpregset_t nt_fpregset;
143
144	memset(&nt_fpregset, 0, sizeof(nt_fpregset));
145	memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));
146	memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));
147
148	return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),
149	"CORE");
150	}
151
152	/*
153	* Initialize timer note
154	*/
155	static void nt_s390_timer(void ptr, struct save_area *sa)
156	{
157	return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
158	KEXEC_CORE_NOTE_NAME);
159	}
160
161	/*
162	* Initialize TOD clock comparator note
163	*/
164	static void nt_s390_tod_cmp(void ptr, struct save_area *sa)
165	{
166	return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
167	sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);
168	}
169
170	/*
171	* Initialize TOD programmable register note
172	*/
173	static void nt_s390_tod_preg(void ptr, struct save_area *sa)
174	{
175	return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
176	sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);
177	}
178
179	/*
180	* Initialize control register note
181	*/
182	static void nt_s390_ctrs(void ptr, struct save_area *sa)
183	{
184	return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
185	sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);
186	}
187
188	/*
189	* Initialize prefix register note
190	*/
191	static void nt_s390_prefix(void ptr, struct save_area *sa)
192	{
193	return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
194	sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);
195	}
196
197	/*
198	* Fill ELF notes for one CPU with save area registers
199	*/
200	void fill_cpu_elf_notes(void ptr, struct save_area *sa)
201	{
202	ptr = nt_prstatus(ptr, sa);
203	ptr = nt_fpregset(ptr, sa);
204	ptr = nt_s390_timer(ptr, sa);
205	ptr = nt_s390_tod_cmp(ptr, sa);
206	ptr = nt_s390_tod_preg(ptr, sa);
207	ptr = nt_s390_ctrs(ptr, sa);
208	ptr = nt_s390_prefix(ptr, sa);
209	return ptr;
210	}
211
212	/*
213	* Initialize prpsinfo note (new kernel)
214	*/
215	static void nt_prpsinfo(void ptr)
216	{
217	struct elf_prpsinfo prpsinfo;
218
219	memset(&prpsinfo, 0, sizeof(prpsinfo));
220	prpsinfo.pr_sname = 'R';
221	strcpy(prpsinfo.pr_fname, "vmlinux");
222	return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),
223	KEXEC_CORE_NOTE_NAME);
224	}
225
226	/*
227	* Initialize vmcoreinfo note (new kernel)
228	*/
229	static void nt_vmcoreinfo(void ptr)
230	{
231	char nt_name[11], *vmcoreinfo;
232	Elf64_Nhdr note;
233	void *addr;
234
235	if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
236	return ptr;
237	memset(nt_name, 0, sizeof(nt_name));
238	if (copy_from_oldmem(&note, addr, sizeof(note)))
239	return ptr;
240	if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
241	return ptr;
242	if (strcmp(nt_name, "VMCOREINFO") != 0)
243	return ptr;
244	vmcoreinfo = kzalloc_panic(note.n_descsz + 1);
245	if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
246	return ptr;
247	vmcoreinfo[note.n_descsz + 1] = 0;
248	return nt_init(ptr, 0, vmcoreinfo, note.n_descsz, "VMCOREINFO");
249	}
250
251	/*
252	* Initialize ELF header (new kernel)
253	*/
254	static void ehdr_init(Elf64_Ehdr ehdr, int mem_chunk_cnt)
255	{
256	memset(ehdr, 0, sizeof(*ehdr));
257	memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
258	ehdr->e_ident[EI_CLASS] = ELFCLASS64;
259	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
260	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
261	memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
262	ehdr->e_type = ET_CORE;
263	ehdr->e_machine = EM_S390;
264	ehdr->e_version = EV_CURRENT;
265	ehdr->e_phoff = sizeof(Elf64_Ehdr);
266	ehdr->e_ehsize = sizeof(Elf64_Ehdr);
267	ehdr->e_phentsize = sizeof(Elf64_Phdr);
268	ehdr->e_phnum = mem_chunk_cnt + 1;
269	return ehdr + 1;
270	}
271
272	/*
273	* Return CPU count for ELF header (new kernel)
274	*/
275	static int get_cpu_cnt(void)
276	{
277	int i, cpus = 0;
278
279	for (i = 0; zfcpdump_save_areas[i]; i++) {
280	if (zfcpdump_save_areas[i]->pref_reg == 0)
281	continue;
282	cpus++;
283	}
284	return cpus;
285	}
286
287	/*
288	* Return memory chunk count for ELF header (new kernel)
289	*/
290	static int get_mem_chunk_cnt(void)
291	{
292	struct mem_chunk chunk_array, mem_chunk;
293	int i, cnt = 0;
294
295	chunk_array = get_memory_layout();
296	for (i = 0; i < MEMORY_CHUNKS; i++) {
297	mem_chunk = &chunk_array[i];
298	if (chunk_array[i].type != CHUNK_READ_WRITE &&
299	chunk_array[i].type != CHUNK_READ_ONLY)
300	continue;
301	if (mem_chunk->size == 0)
302	continue;
303	cnt++;
304	}
305	kfree(chunk_array);
306	return cnt;
307	}
308
309	/*
310	* Relocate pointer in order to allow vmcore code access the data
311	*/
312	static inline unsigned long relocate(unsigned long addr)
313	{
314	return OLDMEM_BASE + addr;
315	}
316
317	/*
318	* Initialize ELF loads (new kernel)
319	*/
320	static int loads_init(Elf64_Phdr *phdr, u64 loads_offset)
321	{
322	struct mem_chunk chunk_array, mem_chunk;
323	int i;
324
325	chunk_array = get_memory_layout();
326	for (i = 0; i < MEMORY_CHUNKS; i++) {
327	mem_chunk = &chunk_array[i];
328	if (mem_chunk->size == 0)
329	break;
330	if (chunk_array[i].type != CHUNK_READ_WRITE &&
331	chunk_array[i].type != CHUNK_READ_ONLY)
332	continue;
333	else
334	phdr->p_filesz = mem_chunk->size;
335	phdr->p_type = PT_LOAD;
336	phdr->p_offset = mem_chunk->addr;
337	phdr->p_vaddr = mem_chunk->addr;
338	phdr->p_paddr = mem_chunk->addr;
339	phdr->p_memsz = mem_chunk->size;
340	phdr->p_flags = PF_R \| PF_W \| PF_X;
341	phdr->p_align = PAGE_SIZE;
342	phdr++;
343	}
344	kfree(chunk_array);
345	return i;
346	}
347
348	/*
349	* Initialize notes (new kernel)
350	*/
351	static void notes_init(Elf64_Phdr phdr, void *ptr, u64 notes_offset)
352	{
353	struct save_area *sa;
354	void *ptr_start = ptr;
355	int i;
356
357	ptr = nt_prpsinfo(ptr);
358
359	for (i = 0; zfcpdump_save_areas[i]; i++) {
360	sa = zfcpdump_save_areas[i];
361	if (sa->pref_reg == 0)
362	continue;
363	ptr = fill_cpu_elf_notes(ptr, sa);
364	}
365	ptr = nt_vmcoreinfo(ptr);
366	memset(phdr, 0, sizeof(*phdr));
367	phdr->p_type = PT_NOTE;
368	phdr->p_offset = relocate(notes_offset);
369	phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
370	phdr->p_memsz = phdr->p_filesz;
371	return ptr;
372	}
373
374	/*
375	* Create ELF core header (new kernel)
376	*/
377	static void s390_elf_corehdr_create(char *elfcorebuf, size_t elfcorebuf_sz)
378	{
379	Elf64_Phdr phdr_notes, phdr_loads;
380	int mem_chunk_cnt;
381	void ptr, hdr;
382	u32 alloc_size;
383	u64 hdr_off;
384
385	mem_chunk_cnt = get_mem_chunk_cnt();
386
387	alloc_size = 0x1000 + get_cpu_cnt() * 0x300 +
388	mem_chunk_cnt * sizeof(Elf64_Phdr);
389	hdr = kzalloc_panic(alloc_size);
390	/* Init elf header */
391	ptr = ehdr_init(hdr, mem_chunk_cnt);
392	/* Init program headers */
393	phdr_notes = ptr;
394	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
395	phdr_loads = ptr;
396	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
397	/* Init notes */
398	hdr_off = PTR_DIFF(ptr, hdr);
399	ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
400	/* Init loads */
401	hdr_off = PTR_DIFF(ptr, hdr);
402	loads_init(phdr_loads, ((unsigned long) hdr) + hdr_off);
403	*elfcorebuf_sz = hdr_off;
404	elfcorebuf = (void ) relocate((unsigned long) hdr);
405	BUG_ON(*elfcorebuf_sz > alloc_size);
406	}
407
408	/*
409	* Create kdump ELF core header in new kernel, if it has not been passed via
410	* the "elfcorehdr" kernel parameter
411	*/
412	static int setup_kdump_elfcorehdr(void)
413	{
414	size_t elfcorebuf_sz;
415	char *elfcorebuf;
416
417	if (!OLDMEM_BASE \|\| is_kdump_kernel())
418	return -EINVAL;
419	s390_elf_corehdr_create(&elfcorebuf, &elfcorebuf_sz);
420	elfcorehdr_addr = (unsigned long long) elfcorebuf;
421	elfcorehdr_size = elfcorebuf_sz;
422	return 0;
423	}
424
425	subsys_initcall(setup_kdump_elfcorehdr);