[deliverable/linux.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/os_info.h>
#include <asm/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
 */
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);
}

/*
 * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
 */
static void *get_vmcoreinfo_old(unsigned long *size)
{
	char nt_name[11], *vmcoreinfo;
	Elf64_Nhdr note;
	void *addr;

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

/*
 * Initialize vmcoreinfo note (new kernel)
 */
static void *nt_vmcoreinfo(void *ptr)
{
	unsigned long size;
	void *vmcoreinfo;

	vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
	if (!vmcoreinfo)
		vmcoreinfo = get_vmcoreinfo_old(&size);
	if (!vmcoreinfo)
		return ptr;
	return nt_init(ptr, 0, vmcoreinfo, size, "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>
60a0c68d MH	15	#include <linux/elf.h>
4857d4bb	16	#include <asm/os_info.h>
6b563d8c HC	17	#include <asm/elf.h>
6b563d8c HC	18	#include <asm/ipl.h>
60a0c68d MH	19
	20	#define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
	21	#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
	22	#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
	23
	24	/*
	25	* Copy one page from "oldmem"
	26	*
	27	* For the kdump reserved memory this functions performs a swap operation:
	28	* - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
	29	* - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
	30	*/
	31	ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
	32	size_t csize, unsigned long offset, int userbuf)
	33	{
	34	unsigned long src;
60a0c68d MH	35
	36	if (!csize)
	37	return 0;
	38
	39	src = (pfn << PAGE_SHIFT) + offset;
	40	if (src < OLDMEM_SIZE)
	41	src += OLDMEM_BASE;
	42	else if (src > OLDMEM_BASE &&
	43	src < OLDMEM_BASE + OLDMEM_SIZE)
	44	src -= OLDMEM_BASE;
	45	if (userbuf)
07ea815b MH	46	copy_to_user_real((void __force __user ) buf, (void ) src,
07ea815b MH	47	csize);
60a0c68d	48	else
07ea815b MH	49	memcpy_real(buf, (void *) src, csize);
07ea815b MH	50	return csize;
60a0c68d MH	51	}
	52
	53	/*
	54	* Copy memory from old kernel
	55	*/
4857d4bb	56	int copy_from_oldmem(void dest, void src, size_t count)
60a0c68d MH	57	{
	58	unsigned long copied = 0;
	59	int rc;
	60
	61	if ((unsigned long) src < OLDMEM_SIZE) {
	62	copied = min(count, OLDMEM_SIZE - (unsigned long) src);
	63	rc = memcpy_real(dest, src + OLDMEM_BASE, copied);
	64	if (rc)
	65	return rc;
	66	}
	67	return memcpy_real(dest + copied, src + copied, count - copied);
	68	}
	69
	70	/*
	71	* Alloc memory and panic in case of ENOMEM
	72	*/
	73	static void *kzalloc_panic(int len)
	74	{
	75	void *rc;
	76
	77	rc = kzalloc(len, GFP_KERNEL);
	78	if (!rc)
	79	panic("s390 kdump kzalloc (%d) failed", len);
	80	return rc;
	81	}
	82
	83	/*
	84	* Get memory layout and create hole for oldmem
	85	*/
	86	static struct mem_chunk *get_memory_layout(void)
	87	{
	88	struct mem_chunk *chunk_array;
	89
	90	chunk_array = kzalloc_panic(MEMORY_CHUNKS * sizeof(struct mem_chunk));
	91	detect_memory_layout(chunk_array);
	92	create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE, CHUNK_CRASHK);
	93	return chunk_array;
	94	}
	95
	96	/*
	97	* Initialize ELF note
	98	*/
	99	static void nt_init(void buf, Elf64_Word type, void *desc, int d_len,
	100	const char *name)
	101	{
	102	Elf64_Nhdr *note;
	103	u64 len;
	104
	105	note = (Elf64_Nhdr *)buf;
	106	note->n_namesz = strlen(name) + 1;
	107	note->n_descsz = d_len;
	108	note->n_type = type;
	109	len = sizeof(Elf64_Nhdr);
	110
	111	memcpy(buf + len, name, note->n_namesz);
	112	len = roundup(len + note->n_namesz, 4);
	113
	114	memcpy(buf + len, desc, note->n_descsz);
	115	len = roundup(len + note->n_descsz, 4);
	116
	117	return PTR_ADD(buf, len);
	118	}
	119
	120	/*
121	* Initialize prstatus note
122	*/
123	static void nt_prstatus(void ptr, struct save_area *sa)
124	{
125	struct elf_prstatus nt_prstatus;
126	static int cpu_nr = 1;
127
128	memset(&nt_prstatus, 0, sizeof(nt_prstatus));
129	memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));
130	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
131	memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));
132	nt_prstatus.pr_pid = cpu_nr;
133	cpu_nr++;
134
135	return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),
136	"CORE");
137	}
138
139	/*
140	* Initialize fpregset (floating point) note
141	*/
142	static void nt_fpregset(void ptr, struct save_area *sa)
143	{
144	elf_fpregset_t nt_fpregset;
145
146	memset(&nt_fpregset, 0, sizeof(nt_fpregset));
147	memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));
148	memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));
149
150	return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),
151	"CORE");
152	}
153
154	/*
155	* Initialize timer note
156	*/
157	static void nt_s390_timer(void ptr, struct save_area *sa)
158	{
159	return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
160	KEXEC_CORE_NOTE_NAME);
161	}
162
163	/*
164	* Initialize TOD clock comparator note
165	*/
166	static void nt_s390_tod_cmp(void ptr, struct save_area *sa)
167	{
168	return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
169	sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);
170	}
171
172	/*
173	* Initialize TOD programmable register note
174	*/
175	static void nt_s390_tod_preg(void ptr, struct save_area *sa)
176	{
177	return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
178	sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);
179	}
180
181	/*
182	* Initialize control register note
183	*/
184	static void nt_s390_ctrs(void ptr, struct save_area *sa)
185	{
186	return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
187	sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);
188	}
189
190	/*
191	* Initialize prefix register note
192	*/
193	static void nt_s390_prefix(void ptr, struct save_area *sa)
194	{
195	return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
196	sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);
197	}
198
199	/*
200	* Fill ELF notes for one CPU with save area registers
201	*/
202	void fill_cpu_elf_notes(void ptr, struct save_area *sa)
203	{
204	ptr = nt_prstatus(ptr, sa);
205	ptr = nt_fpregset(ptr, sa);
206	ptr = nt_s390_timer(ptr, sa);
207	ptr = nt_s390_tod_cmp(ptr, sa);
208	ptr = nt_s390_tod_preg(ptr, sa);
209	ptr = nt_s390_ctrs(ptr, sa);
210	ptr = nt_s390_prefix(ptr, sa);
211	return ptr;
212	}
213
214	/*
215	* Initialize prpsinfo note (new kernel)
216	*/
217	static void nt_prpsinfo(void ptr)
218	{
219	struct elf_prpsinfo prpsinfo;
220
221	memset(&prpsinfo, 0, sizeof(prpsinfo));
222	prpsinfo.pr_sname = 'R';
223	strcpy(prpsinfo.pr_fname, "vmlinux");
224	return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),
225	KEXEC_CORE_NOTE_NAME);
226	}
227
228	/*
4857d4bb	229	* Get vmcoreinfo using lowcore->vmcore_info (new kernel)
60a0c68d	230	*/
4857d4bb	231	static void get_vmcoreinfo_old(unsigned long size)
60a0c68d MH	232	{
	233	char nt_name[11], *vmcoreinfo;
	234	Elf64_Nhdr note;
	235	void *addr;
	236
	237	if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
4857d4bb	238	return NULL;
60a0c68d MH	239	memset(nt_name, 0, sizeof(nt_name));
60a0c68d MH	240	if (copy_from_oldmem(&note, addr, sizeof(note)))
4857d4bb	241	return NULL;
60a0c68d	242	if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
4857d4bb	243	return NULL;
60a0c68d	244	if (strcmp(nt_name, "VMCOREINFO") != 0)
4857d4bb MH	245	return NULL;
4857d4bb MH	246	vmcoreinfo = kzalloc_panic(note.n_descsz);
60a0c68d	247	if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
4857d4bb MH	248	return NULL;
	249	*size = note.n_descsz;
	250	return vmcoreinfo;
	251	}
	252
	253	/*
	254	* Initialize vmcoreinfo note (new kernel)
	255	*/
	256	static void nt_vmcoreinfo(void ptr)
	257	{
	258	unsigned long size;
	259	void *vmcoreinfo;
	260
	261	vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
	262	if (!vmcoreinfo)
	263	vmcoreinfo = get_vmcoreinfo_old(&size);
	264	if (!vmcoreinfo)
60a0c68d	265	return ptr;
4857d4bb	266	return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO");
60a0c68d MH	267	}
	268
	269	/*
	270	* Initialize ELF header (new kernel)
	271	*/
	272	static void ehdr_init(Elf64_Ehdr ehdr, int mem_chunk_cnt)
	273	{
	274	memset(ehdr, 0, sizeof(*ehdr));
	275	memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
	276	ehdr->e_ident[EI_CLASS] = ELFCLASS64;
	277	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
	278	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
	279	memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
	280	ehdr->e_type = ET_CORE;
	281	ehdr->e_machine = EM_S390;
	282	ehdr->e_version = EV_CURRENT;
	283	ehdr->e_phoff = sizeof(Elf64_Ehdr);
	284	ehdr->e_ehsize = sizeof(Elf64_Ehdr);
	285	ehdr->e_phentsize = sizeof(Elf64_Phdr);
	286	ehdr->e_phnum = mem_chunk_cnt + 1;
	287	return ehdr + 1;
	288	}
	289
	290	/*
	291	* Return CPU count for ELF header (new kernel)
	292	*/
	293	static int get_cpu_cnt(void)
	294	{
	295	int i, cpus = 0;
	296
	297	for (i = 0; zfcpdump_save_areas[i]; i++) {
	298	if (zfcpdump_save_areas[i]->pref_reg == 0)
	299	continue;
	300	cpus++;
	301	}
	302	return cpus;
	303	}
	304
	305	/*
	306	* Return memory chunk count for ELF header (new kernel)
	307	*/
	308	static int get_mem_chunk_cnt(void)
	309	{
	310	struct mem_chunk chunk_array, mem_chunk;
	311	int i, cnt = 0;
	312
	313	chunk_array = get_memory_layout();
	314	for (i = 0; i < MEMORY_CHUNKS; i++) {
	315	mem_chunk = &chunk_array[i];
	316	if (chunk_array[i].type != CHUNK_READ_WRITE &&
	317	chunk_array[i].type != CHUNK_READ_ONLY)
	318	continue;
	319	if (mem_chunk->size == 0)
	320	continue;
	321	cnt++;
	322	}
	323	kfree(chunk_array);
	324	return cnt;
	325	}
	326
	327	/*
	328	* Relocate pointer in order to allow vmcore code access the data
	329	*/
	330	static inline unsigned long relocate(unsigned long addr)
331	{
332	return OLDMEM_BASE + addr;
333	}
334
335	/*
336	* Initialize ELF loads (new kernel)
337	*/
338	static int loads_init(Elf64_Phdr *phdr, u64 loads_offset)
339	{
340	struct mem_chunk chunk_array, mem_chunk;
341	int i;
342
343	chunk_array = get_memory_layout();
344	for (i = 0; i < MEMORY_CHUNKS; i++) {
345	mem_chunk = &chunk_array[i];
346	if (mem_chunk->size == 0)
347	break;
348	if (chunk_array[i].type != CHUNK_READ_WRITE &&
349	chunk_array[i].type != CHUNK_READ_ONLY)
350	continue;
351	else
352	phdr->p_filesz = mem_chunk->size;
353	phdr->p_type = PT_LOAD;
354	phdr->p_offset = mem_chunk->addr;
355	phdr->p_vaddr = mem_chunk->addr;
356	phdr->p_paddr = mem_chunk->addr;
357	phdr->p_memsz = mem_chunk->size;
358	phdr->p_flags = PF_R \| PF_W \| PF_X;
359	phdr->p_align = PAGE_SIZE;
360	phdr++;
361	}
362	kfree(chunk_array);
363	return i;
364	}
365
366	/*
367	* Initialize notes (new kernel)
368	*/
369	static void notes_init(Elf64_Phdr phdr, void *ptr, u64 notes_offset)
370	{
371	struct save_area *sa;
372	void *ptr_start = ptr;
373	int i;
374
375	ptr = nt_prpsinfo(ptr);
376
377	for (i = 0; zfcpdump_save_areas[i]; i++) {
378	sa = zfcpdump_save_areas[i];
379	if (sa->pref_reg == 0)
380	continue;
381	ptr = fill_cpu_elf_notes(ptr, sa);
382	}
383	ptr = nt_vmcoreinfo(ptr);
384	memset(phdr, 0, sizeof(*phdr));
385	phdr->p_type = PT_NOTE;
386	phdr->p_offset = relocate(notes_offset);
387	phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
388	phdr->p_memsz = phdr->p_filesz;
389	return ptr;
390	}
391
392	/*
393	* Create ELF core header (new kernel)
394	*/
395	static void s390_elf_corehdr_create(char *elfcorebuf, size_t elfcorebuf_sz)
396	{
397	Elf64_Phdr phdr_notes, phdr_loads;
398	int mem_chunk_cnt;
399	void ptr, hdr;
400	u32 alloc_size;
401	u64 hdr_off;
402
403	mem_chunk_cnt = get_mem_chunk_cnt();
404
405	alloc_size = 0x1000 + get_cpu_cnt() * 0x300 +
406	mem_chunk_cnt * sizeof(Elf64_Phdr);
407	hdr = kzalloc_panic(alloc_size);
408	/* Init elf header */
409	ptr = ehdr_init(hdr, mem_chunk_cnt);
410	/* Init program headers */
411	phdr_notes = ptr;
412	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
413	phdr_loads = ptr;
414	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
415	/* Init notes */
416	hdr_off = PTR_DIFF(ptr, hdr);
417	ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
418	/* Init loads */
419	hdr_off = PTR_DIFF(ptr, hdr);
420	loads_init(phdr_loads, ((unsigned long) hdr) + hdr_off);
421	*elfcorebuf_sz = hdr_off;
422	elfcorebuf = (void ) relocate((unsigned long) hdr);
423	BUG_ON(*elfcorebuf_sz > alloc_size);
424	}
425
426	/*
427	* Create kdump ELF core header in new kernel, if it has not been passed via
428	* the "elfcorehdr" kernel parameter
429	*/
430	static int setup_kdump_elfcorehdr(void)
431	{
432	size_t elfcorebuf_sz;
433	char *elfcorebuf;
434
435	if (!OLDMEM_BASE \|\| is_kdump_kernel())
436	return -EINVAL;
437	s390_elf_corehdr_create(&elfcorebuf, &elfcorebuf_sz);
438	elfcorehdr_addr = (unsigned long long) elfcorebuf;
439	elfcorehdr_size = elfcorebuf_sz;
440	return 0;
441	}
442
443	subsys_initcall(setup_kdump_elfcorehdr);