[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>
#include <asm/sclp.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))))


/*
 * Return physical address for virtual address
 */
static inline void *load_real_addr(void *addr)
{
	unsigned long real_addr;

	asm volatile(
		   "	lra     %0,0(%1)\n"
		   "	jz	0f\n"
		   "	la	%0,0\n"
		   "0:"
		   : "=a" (real_addr) : "a" (addr) : "cc");
	return (void *)real_addr;
}

/*
 * Copy up to one page to vmalloc or real memory
 */
static ssize_t copy_page_real(void *buf, void *src, size_t csize)
{
	size_t size;

	if (is_vmalloc_addr(buf)) {
		BUG_ON(csize >= PAGE_SIZE);
		/* If buf is not page aligned, copy first part */
		size = min(roundup(__pa(buf), PAGE_SIZE) - __pa(buf), csize);
		if (size) {
			if (memcpy_real(load_real_addr(buf), src, size))
				return -EFAULT;
			buf += size;
			src += size;
		}
		/* Copy second part */
		size = csize - size;
		return (size) ? memcpy_real(load_real_addr(buf), src, size) : 0;
	} else {
		return memcpy_real(buf, src, csize);
	}
}

/*
 * Pointer to ELF header in new kernel
 */
static void *elfcorehdr_newmem;

/*
 * Copy one page from zfcpdump "oldmem"
 *
 * For pages below ZFCPDUMP_HSA_SIZE memory from the HSA is copied. Otherwise
 * real memory copy is used.
 */
static ssize_t copy_oldmem_page_zfcpdump(char *buf, size_t csize,
					 unsigned long src, int userbuf)
{
	int rc;

	if (src < ZFCPDUMP_HSA_SIZE) {
		rc = memcpy_hsa(buf, src, csize, userbuf);
	} else {
		if (userbuf)
			rc = copy_to_user_real((void __force __user *) buf,
					       (void *) src, csize);
		else
			rc = memcpy_real(buf, (void *) src, csize);
	}
	return rc ? rc : csize;
}

/*
 * Copy one page from kdump "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]
 */
static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize,
				      unsigned long src, int userbuf)

{
	int rc;

	if (src < OLDMEM_SIZE)
		src += OLDMEM_BASE;
	else if (src > OLDMEM_BASE &&
		 src < OLDMEM_BASE + OLDMEM_SIZE)
		src -= OLDMEM_BASE;
	if (userbuf)
		rc = copy_to_user_real((void __force __user *) buf,
				       (void *) src, csize);
	else
		rc = copy_page_real(buf, (void *) src, csize);
	return (rc == 0) ? rc : csize;
}

/*
 * Copy one page from "oldmem"
 */
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 (OLDMEM_BASE)
		return copy_oldmem_page_kdump(buf, csize, src, userbuf);
	else
		return copy_oldmem_page_zfcpdump(buf, csize, src, userbuf);
}

/*
 * Remap "oldmem" for kdump
 *
 * For the kdump reserved memory this functions performs a swap operation:
 * [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
 */
static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
					unsigned long from, unsigned long pfn,
					unsigned long size, pgprot_t prot)
{
	unsigned long size_old;
	int rc;

	if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
		size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
		rc = remap_pfn_range(vma, from,
				     pfn + (OLDMEM_BASE >> PAGE_SHIFT),
				     size_old, prot);
		if (rc || size == size_old)
			return rc;
		size -= size_old;
		from += size_old;
		pfn += size_old >> PAGE_SHIFT;
	}
	return remap_pfn_range(vma, from, pfn, size, prot);
}

/*
 * Remap "oldmem" for zfcpdump
 *
 * We only map available memory above ZFCPDUMP_HSA_SIZE. Memory below
 * ZFCPDUMP_HSA_SIZE is read on demand using the copy_oldmem_page() function.
 */
static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
					   unsigned long from,
					   unsigned long pfn,
					   unsigned long size, pgprot_t prot)
{
	unsigned long size_hsa;

	if (pfn < ZFCPDUMP_HSA_SIZE >> PAGE_SHIFT) {
		size_hsa = min(size, ZFCPDUMP_HSA_SIZE - (pfn << PAGE_SHIFT));
		if (size == size_hsa)
			return 0;
		size -= size_hsa;
		from += size_hsa;
		pfn += size_hsa >> PAGE_SHIFT;
	}
	return remap_pfn_range(vma, from, pfn, size, prot);
}

/*
 * Remap "oldmem" for kdump or zfcpdump
 */
int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
			   unsigned long pfn, unsigned long size, pgprot_t prot)
{
	if (OLDMEM_BASE)
		return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
	else
		return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
						       prot);
}

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

	if (OLDMEM_BASE) {
		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;
		}
	} else {
		if ((unsigned long) src < ZFCPDUMP_HSA_SIZE) {
			copied = min(count,
				     ZFCPDUMP_HSA_SIZE - (unsigned long) src);
			rc = memcpy_hsa(dest, (unsigned long) src, copied, 0);
			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, 0);
	create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE);
	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;
}

/*
 * 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)
			continue;
		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 = 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)
 */
int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
{
	Elf64_Phdr *phdr_notes, *phdr_loads;
	int mem_chunk_cnt;
	void *ptr, *hdr;
	u32 alloc_size;
	u64 hdr_off;

	/* If we are not in kdump or zfcpdump mode return */
	if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
		return 0;
	/* If elfcorehdr= has been passed via cmdline, we use that one */
	if (elfcorehdr_addr != ELFCORE_ADDR_MAX)
		return 0;
	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, hdr_off);
	*addr = (unsigned long long) hdr;
	elfcorehdr_newmem = hdr;
	*size = (unsigned long long) hdr_off;
	BUG_ON(elfcorehdr_size > alloc_size);
	return 0;
}

/*
 * Free ELF core header (new kernel)
 */
void elfcorehdr_free(unsigned long long addr)
{
	if (!elfcorehdr_newmem)
		return;
	kfree((void *)(unsigned long)addr);
}

/*
 * Read from ELF header
 */
ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
{
	void *src = (void *)(unsigned long)*ppos;

	src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;
	memcpy(buf, src, count);
	*ppos += count;
	return count;
}

/*
 * Read from ELF notes data
 */
ssize_t elfcorehdr_read_notes(char *buf, size_t count, u64 *ppos)
{
	void *src = (void *)(unsigned long)*ppos;
	int rc;

	if (elfcorehdr_newmem) {
		memcpy(buf, src, count);
	} else {
		rc = copy_from_oldmem(buf, src, count);
		if (rc)
			return rc;
	}
	*ppos += count;
	return count;
}
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>
6f79d332	19	#include <asm/sclp.h>
60a0c68d MH	20
	21	#define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
	22	#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
	23	#define PTR_DIFF(x, y) ((unsigned long)(((char *) (x)) - ((unsigned long) (y))))
	24
191a2fa0 MH	25
	26	/*
	27	* Return physical address for virtual address
	28	*/
	29	static inline void load_real_addr(void addr)
	30	{
	31	unsigned long real_addr;
	32
	33	asm volatile(
	34	" lra %0,0(%1)\n"
	35	" jz 0f\n"
	36	" la %0,0\n"
	37	"0:"
	38	: "=a" (real_addr) : "a" (addr) : "cc");
	39	return (void *)real_addr;
	40	}
	41
	42	/*
	43	* Copy up to one page to vmalloc or real memory
	44	*/
	45	static ssize_t copy_page_real(void buf, void src, size_t csize)
	46	{
	47	size_t size;
	48
	49	if (is_vmalloc_addr(buf)) {
	50	BUG_ON(csize >= PAGE_SIZE);
	51	/* If buf is not page aligned, copy first part */
	52	size = min(roundup(__pa(buf), PAGE_SIZE) - __pa(buf), csize);
	53	if (size) {
	54	if (memcpy_real(load_real_addr(buf), src, size))
	55	return -EFAULT;
	56	buf += size;
	57	src += size;
	58	}
	59	/* Copy second part */
	60	size = csize - size;
	61	return (size) ? memcpy_real(load_real_addr(buf), src, size) : 0;
	62	} else {
	63	return memcpy_real(buf, src, csize);
	64	}
	65	}
	66
97b0f6f9 MH	67	/*
	68	* Pointer to ELF header in new kernel
	69	*/
	70	static void *elfcorehdr_newmem;
	71
60a0c68d	72	/*
6f79d332 MH	73	* Copy one page from zfcpdump "oldmem"
	74	*
	75	* For pages below ZFCPDUMP_HSA_SIZE memory from the HSA is copied. Otherwise
	76	* real memory copy is used.
	77	*/
	78	static ssize_t copy_oldmem_page_zfcpdump(char *buf, size_t csize,
	79	unsigned long src, int userbuf)
	80	{
	81	int rc;
	82
	83	if (src < ZFCPDUMP_HSA_SIZE) {
	84	rc = memcpy_hsa(buf, src, csize, userbuf);
	85	} else {
	86	if (userbuf)
	87	rc = copy_to_user_real((void __force __user *) buf,
	88	(void *) src, csize);
	89	else
	90	rc = memcpy_real(buf, (void *) src, csize);
	91	}
	92	return rc ? rc : csize;
	93	}
	94
	95	/*
	96	* Copy one page from kdump "oldmem"
60a0c68d MH	97	*
	98	* For the kdump reserved memory this functions performs a swap operation:
	99	* - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
	100	* - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
	101	*/
6f79d332 MH	102	static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize,
	103	unsigned long src, int userbuf)
	104
60a0c68d	105	{
191a2fa0	106	int rc;
60a0c68d	107
60a0c68d MH	108	if (src < OLDMEM_SIZE)
	109	src += OLDMEM_BASE;
	110	else if (src > OLDMEM_BASE &&
	111	src < OLDMEM_BASE + OLDMEM_SIZE)
	112	src -= OLDMEM_BASE;
	113	if (userbuf)
191a2fa0 MH	114	rc = copy_to_user_real((void __force __user *) buf,
191a2fa0 MH	115	(void *) src, csize);
60a0c68d	116	else
191a2fa0	117	rc = copy_page_real(buf, (void *) src, csize);
6f79d332 MH	118	return (rc == 0) ? rc : csize;
	119	}
	120
	121	/*
	122	* Copy one page from "oldmem"
	123	*/
	124	ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
	125	unsigned long offset, int userbuf)
	126	{
	127	unsigned long src;
	128
	129	if (!csize)
	130	return 0;
	131	src = (pfn << PAGE_SHIFT) + offset;
	132	if (OLDMEM_BASE)
	133	return copy_oldmem_page_kdump(buf, csize, src, userbuf);
	134	else
	135	return copy_oldmem_page_zfcpdump(buf, csize, src, userbuf);
60a0c68d MH	136	}
60a0c68d MH	137
23df79da	138	/*
6f79d332	139	* Remap "oldmem" for kdump
23df79da JW	140	*
	141	* For the kdump reserved memory this functions performs a swap operation:
	142	* [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
	143	*/
6f79d332 MH	144	static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
	145	unsigned long from, unsigned long pfn,
	146	unsigned long size, pgprot_t prot)
23df79da JW	147	{
	148	unsigned long size_old;
	149	int rc;
	150
	151	if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
	152	size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
	153	rc = remap_pfn_range(vma, from,
	154	pfn + (OLDMEM_BASE >> PAGE_SHIFT),
	155	size_old, prot);
	156	if (rc \|\| size == size_old)
	157	return rc;
	158	size -= size_old;
	159	from += size_old;
	160	pfn += size_old >> PAGE_SHIFT;
	161	}
	162	return remap_pfn_range(vma, from, pfn, size, prot);
	163	}
	164
6f79d332 MH	165	/*
	166	* Remap "oldmem" for zfcpdump
	167	*
	168	* We only map available memory above ZFCPDUMP_HSA_SIZE. Memory below
	169	* ZFCPDUMP_HSA_SIZE is read on demand using the copy_oldmem_page() function.
	170	*/
	171	static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
	172	unsigned long from,
	173	unsigned long pfn,
	174	unsigned long size, pgprot_t prot)
	175	{
	176	unsigned long size_hsa;
	177
	178	if (pfn < ZFCPDUMP_HSA_SIZE >> PAGE_SHIFT) {
	179	size_hsa = min(size, ZFCPDUMP_HSA_SIZE - (pfn << PAGE_SHIFT));
	180	if (size == size_hsa)
	181	return 0;
	182	size -= size_hsa;
	183	from += size_hsa;
	184	pfn += size_hsa >> PAGE_SHIFT;
	185	}
	186	return remap_pfn_range(vma, from, pfn, size, prot);
	187	}
	188
	189	/*
	190	* Remap "oldmem" for kdump or zfcpdump
	191	*/
	192	int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
	193	unsigned long pfn, unsigned long size, pgprot_t prot)
	194	{
	195	if (OLDMEM_BASE)
	196	return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
	197	else
	198	return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
	199	prot);
	200	}
	201
60a0c68d MH	202	/*
	203	* Copy memory from old kernel
	204	*/
4857d4bb	205	int copy_from_oldmem(void dest, void src, size_t count)
60a0c68d MH	206	{
	207	unsigned long copied = 0;
	208	int rc;
	209
6f79d332 MH	210	if (OLDMEM_BASE) {
	211	if ((unsigned long) src < OLDMEM_SIZE) {
	212	copied = min(count, OLDMEM_SIZE - (unsigned long) src);
	213	rc = memcpy_real(dest, src + OLDMEM_BASE, copied);
	214	if (rc)
	215	return rc;
	216	}
	217	} else {
	218	if ((unsigned long) src < ZFCPDUMP_HSA_SIZE) {
	219	copied = min(count,
	220	ZFCPDUMP_HSA_SIZE - (unsigned long) src);
	221	rc = memcpy_hsa(dest, (unsigned long) src, copied, 0);
	222	if (rc)
	223	return rc;
	224	}
60a0c68d MH	225	}
	226	return memcpy_real(dest + copied, src + copied, count - copied);
	227	}
	228
	229	/*
	230	* Alloc memory and panic in case of ENOMEM
	231	*/
	232	static void *kzalloc_panic(int len)
	233	{
	234	void *rc;
	235
	236	rc = kzalloc(len, GFP_KERNEL);
	237	if (!rc)
	238	panic("s390 kdump kzalloc (%d) failed", len);
	239	return rc;
	240	}
	241
	242	/*
	243	* Get memory layout and create hole for oldmem
	244	*/
	245	static struct mem_chunk *get_memory_layout(void)
	246	{
	247	struct mem_chunk *chunk_array;
	248
	249	chunk_array = kzalloc_panic(MEMORY_CHUNKS * sizeof(struct mem_chunk));
df1bd59c	250	detect_memory_layout(chunk_array, 0);
996b4a7d	251	create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE);
60a0c68d MH	252	return chunk_array;
	253	}
	254
	255	/*
	256	* Initialize ELF note
	257	*/
	258	static void nt_init(void buf, Elf64_Word type, void *desc, int d_len,
	259	const char *name)
	260	{
	261	Elf64_Nhdr *note;
	262	u64 len;
	263
	264	note = (Elf64_Nhdr *)buf;
	265	note->n_namesz = strlen(name) + 1;
	266	note->n_descsz = d_len;
	267	note->n_type = type;
	268	len = sizeof(Elf64_Nhdr);
	269
	270	memcpy(buf + len, name, note->n_namesz);
	271	len = roundup(len + note->n_namesz, 4);
	272
	273	memcpy(buf + len, desc, note->n_descsz);
	274	len = roundup(len + note->n_descsz, 4);
	275
	276	return PTR_ADD(buf, len);
	277	}
	278
	279	/*
	280	* Initialize prstatus note
	281	*/
	282	static void nt_prstatus(void ptr, struct save_area *sa)
	283	{
	284	struct elf_prstatus nt_prstatus;
	285	static int cpu_nr = 1;
	286
	287	memset(&nt_prstatus, 0, sizeof(nt_prstatus));
	288	memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));
	289	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
	290	memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));
	291	nt_prstatus.pr_pid = cpu_nr;
	292	cpu_nr++;
	293
	294	return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),
	295	"CORE");
	296	}
	297
	298	/*
	299	* Initialize fpregset (floating point) note
	300	*/
	301	static void nt_fpregset(void ptr, struct save_area *sa)
	302	{
	303	elf_fpregset_t nt_fpregset;
	304
	305	memset(&nt_fpregset, 0, sizeof(nt_fpregset));
	306	memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));
	307	memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));
	308
	309	return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),
	310	"CORE");
	311	}
	312
	313	/*
	314	* Initialize timer note
	315	*/
316	static void nt_s390_timer(void ptr, struct save_area *sa)
317	{
318	return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
319	KEXEC_CORE_NOTE_NAME);
320	}
321
322	/*
323	* Initialize TOD clock comparator note
324	*/
325	static void nt_s390_tod_cmp(void ptr, struct save_area *sa)
326	{
327	return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
328	sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);
329	}
330
331	/*
332	* Initialize TOD programmable register note
333	*/
334	static void nt_s390_tod_preg(void ptr, struct save_area *sa)
335	{
336	return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
337	sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);
338	}
339
340	/*
341	* Initialize control register note
342	*/
343	static void nt_s390_ctrs(void ptr, struct save_area *sa)
344	{
345	return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
346	sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);
347	}
348
349	/*
350	* Initialize prefix register note
351	*/
352	static void nt_s390_prefix(void ptr, struct save_area *sa)
353	{
354	return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
355	sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);
356	}
357
358	/*
359	* Fill ELF notes for one CPU with save area registers
360	*/
361	void fill_cpu_elf_notes(void ptr, struct save_area *sa)
362	{
363	ptr = nt_prstatus(ptr, sa);
364	ptr = nt_fpregset(ptr, sa);
365	ptr = nt_s390_timer(ptr, sa);
366	ptr = nt_s390_tod_cmp(ptr, sa);
367	ptr = nt_s390_tod_preg(ptr, sa);
368	ptr = nt_s390_ctrs(ptr, sa);
369	ptr = nt_s390_prefix(ptr, sa);
370	return ptr;
371	}
372
373	/*
374	* Initialize prpsinfo note (new kernel)
375	*/
376	static void nt_prpsinfo(void ptr)
377	{
378	struct elf_prpsinfo prpsinfo;
379
380	memset(&prpsinfo, 0, sizeof(prpsinfo));
381	prpsinfo.pr_sname = 'R';
382	strcpy(prpsinfo.pr_fname, "vmlinux");
383	return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),
384	KEXEC_CORE_NOTE_NAME);
385	}
386
387	/*
4857d4bb	388	* Get vmcoreinfo using lowcore->vmcore_info (new kernel)
60a0c68d	389	*/
4857d4bb	390	static void get_vmcoreinfo_old(unsigned long size)
60a0c68d MH	391	{
	392	char nt_name[11], *vmcoreinfo;
	393	Elf64_Nhdr note;
	394	void *addr;
	395
	396	if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
4857d4bb	397	return NULL;
60a0c68d MH	398	memset(nt_name, 0, sizeof(nt_name));
60a0c68d MH	399	if (copy_from_oldmem(&note, addr, sizeof(note)))
4857d4bb	400	return NULL;
60a0c68d	401	if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
4857d4bb	402	return NULL;
60a0c68d	403	if (strcmp(nt_name, "VMCOREINFO") != 0)
4857d4bb MH	404	return NULL;
4857d4bb MH	405	vmcoreinfo = kzalloc_panic(note.n_descsz);
60a0c68d	406	if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
4857d4bb MH	407	return NULL;
	408	*size = note.n_descsz;
	409	return vmcoreinfo;
	410	}
	411
	412	/*
	413	* Initialize vmcoreinfo note (new kernel)
	414	*/
	415	static void nt_vmcoreinfo(void ptr)
	416	{
	417	unsigned long size;
	418	void *vmcoreinfo;
	419
	420	vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
	421	if (!vmcoreinfo)
	422	vmcoreinfo = get_vmcoreinfo_old(&size);
	423	if (!vmcoreinfo)
60a0c68d	424	return ptr;
4857d4bb	425	return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO");
60a0c68d MH	426	}
	427
	428	/*
	429	* Initialize ELF header (new kernel)
	430	*/
	431	static void ehdr_init(Elf64_Ehdr ehdr, int mem_chunk_cnt)
	432	{
	433	memset(ehdr, 0, sizeof(*ehdr));
	434	memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
	435	ehdr->e_ident[EI_CLASS] = ELFCLASS64;
	436	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
	437	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
	438	memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
	439	ehdr->e_type = ET_CORE;
	440	ehdr->e_machine = EM_S390;
	441	ehdr->e_version = EV_CURRENT;
	442	ehdr->e_phoff = sizeof(Elf64_Ehdr);
	443	ehdr->e_ehsize = sizeof(Elf64_Ehdr);
	444	ehdr->e_phentsize = sizeof(Elf64_Phdr);
	445	ehdr->e_phnum = mem_chunk_cnt + 1;
	446	return ehdr + 1;
	447	}
	448
	449	/*
	450	* Return CPU count for ELF header (new kernel)
	451	*/
	452	static int get_cpu_cnt(void)
	453	{
	454	int i, cpus = 0;
	455
	456	for (i = 0; zfcpdump_save_areas[i]; i++) {
	457	if (zfcpdump_save_areas[i]->pref_reg == 0)
	458	continue;
	459	cpus++;
	460	}
	461	return cpus;
	462	}
	463
	464	/*
	465	* Return memory chunk count for ELF header (new kernel)
	466	*/
	467	static int get_mem_chunk_cnt(void)
	468	{
	469	struct mem_chunk chunk_array, mem_chunk;
	470	int i, cnt = 0;
	471
	472	chunk_array = get_memory_layout();
	473	for (i = 0; i < MEMORY_CHUNKS; i++) {
	474	mem_chunk = &chunk_array[i];
	475	if (chunk_array[i].type != CHUNK_READ_WRITE &&
	476	chunk_array[i].type != CHUNK_READ_ONLY)
	477	continue;
	478	if (mem_chunk->size == 0)
	479	continue;
	480	cnt++;
	481	}
	482	kfree(chunk_array);
	483	return cnt;
	484	}
	485
60a0c68d MH	486	/*
	487	* Initialize ELF loads (new kernel)
	488	*/
	489	static int loads_init(Elf64_Phdr *phdr, u64 loads_offset)
	490	{
	491	struct mem_chunk chunk_array, mem_chunk;
	492	int i;
	493
	494	chunk_array = get_memory_layout();
	495	for (i = 0; i < MEMORY_CHUNKS; i++) {
	496	mem_chunk = &chunk_array[i];
	497	if (mem_chunk->size == 0)
996b4a7d	498	continue;
60a0c68d MH	499	if (chunk_array[i].type != CHUNK_READ_WRITE &&
	500	chunk_array[i].type != CHUNK_READ_ONLY)
	501	continue;
	502	else
	503	phdr->p_filesz = mem_chunk->size;
	504	phdr->p_type = PT_LOAD;
	505	phdr->p_offset = mem_chunk->addr;
	506	phdr->p_vaddr = mem_chunk->addr;
	507	phdr->p_paddr = mem_chunk->addr;
	508	phdr->p_memsz = mem_chunk->size;
	509	phdr->p_flags = PF_R \| PF_W \| PF_X;
	510	phdr->p_align = PAGE_SIZE;
	511	phdr++;
	512	}
	513	kfree(chunk_array);
	514	return i;
	515	}
	516
	517	/*
	518	* Initialize notes (new kernel)
	519	*/
	520	static void notes_init(Elf64_Phdr phdr, void *ptr, u64 notes_offset)
	521	{
	522	struct save_area *sa;
	523	void *ptr_start = ptr;
	524	int i;
	525
	526	ptr = nt_prpsinfo(ptr);
	527
	528	for (i = 0; zfcpdump_save_areas[i]; i++) {
	529	sa = zfcpdump_save_areas[i];
	530	if (sa->pref_reg == 0)
	531	continue;
	532	ptr = fill_cpu_elf_notes(ptr, sa);
	533	}
	534	ptr = nt_vmcoreinfo(ptr);
	535	memset(phdr, 0, sizeof(*phdr));
	536	phdr->p_type = PT_NOTE;
97b0f6f9	537	phdr->p_offset = notes_offset;
60a0c68d MH	538	phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
	539	phdr->p_memsz = phdr->p_filesz;
	540	return ptr;
	541	}
	542
	543	/*
	544	* Create ELF core header (new kernel)
	545	*/
97b0f6f9	546	int elfcorehdr_alloc(unsigned long long addr, unsigned long long size)
60a0c68d MH	547	{
	548	Elf64_Phdr phdr_notes, phdr_loads;
	549	int mem_chunk_cnt;
	550	void ptr, hdr;
	551	u32 alloc_size;
	552	u64 hdr_off;
	553
6f79d332 MH	554	/* If we are not in kdump or zfcpdump mode return */
6f79d332 MH	555	if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
97b0f6f9 MH	556	return 0;
	557	/* If elfcorehdr= has been passed via cmdline, we use that one */
	558	if (elfcorehdr_addr != ELFCORE_ADDR_MAX)
	559	return 0;
60a0c68d MH	560	mem_chunk_cnt = get_mem_chunk_cnt();
	561
	562	alloc_size = 0x1000 + get_cpu_cnt() * 0x300 +
	563	mem_chunk_cnt * sizeof(Elf64_Phdr);
	564	hdr = kzalloc_panic(alloc_size);
	565	/* Init elf header */
	566	ptr = ehdr_init(hdr, mem_chunk_cnt);
	567	/* Init program headers */
	568	phdr_notes = ptr;
	569	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
	570	phdr_loads = ptr;
	571	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
	572	/* Init notes */
	573	hdr_off = PTR_DIFF(ptr, hdr);
	574	ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
	575	/* Init loads */
	576	hdr_off = PTR_DIFF(ptr, hdr);
97b0f6f9 MH	577	loads_init(phdr_loads, hdr_off);
	578	*addr = (unsigned long long) hdr;
	579	elfcorehdr_newmem = hdr;
	580	*size = (unsigned long long) hdr_off;
	581	BUG_ON(elfcorehdr_size > alloc_size);
	582	return 0;
60a0c68d MH	583	}
	584
	585	/*
97b0f6f9	586	* Free ELF core header (new kernel)
60a0c68d	587	*/
97b0f6f9	588	void elfcorehdr_free(unsigned long long addr)
60a0c68d	589	{
97b0f6f9 MH	590	if (!elfcorehdr_newmem)
	591	return;
	592	kfree((void *)(unsigned long)addr);
	593	}
	594
	595	/*
	596	* Read from ELF header
	597	*/
	598	ssize_t elfcorehdr_read(char buf, size_t count, u64 ppos)
	599	{
	600	void src = (void )(unsigned long)*ppos;
	601
	602	src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;
	603	memcpy(buf, src, count);
	604	*ppos += count;
	605	return count;
60a0c68d MH	606	}
60a0c68d MH	607
97b0f6f9 MH	608	/*
	609	* Read from ELF notes data
	610	*/
	611	ssize_t elfcorehdr_read_notes(char buf, size_t count, u64 ppos)
	612	{
	613	void src = (void )(unsigned long)*ppos;
	614	int rc;
	615
	616	if (elfcorehdr_newmem) {
	617	memcpy(buf, src, count);
	618	} else {
	619	rc = copy_from_oldmem(buf, src, count);
	620	if (rc)
	621	return rc;
	622	}
	623	*ppos += count;
	624	return count;
	625	}