[linux-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/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))))

struct dump_save_areas dump_save_areas;

/*
 * Allocate and add a save area for a CPU
 */
struct save_area *dump_save_area_create(int cpu)
{
	struct save_area **save_areas, *save_area;

	save_area = kmalloc(sizeof(*save_area), GFP_KERNEL);
	if (!save_area)
		return NULL;
	if (cpu + 1 > dump_save_areas.count) {
		dump_save_areas.count = cpu + 1;
		save_areas = krealloc(dump_save_areas.areas,
				      dump_save_areas.count * sizeof(void *),
				      GFP_KERNEL | __GFP_ZERO);
		if (!save_areas) {
			kfree(save_area);
			return NULL;
		}
		dump_save_areas.areas = save_areas;
	}
	dump_save_areas.areas[cpu] = save_area;
	return save_area;
}

/*
 * 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 real to virtual or real memory
 */
static int copy_from_realmem(void *dest, void *src, size_t count)
{
	unsigned long size;

	if (!count)
		return 0;
	if (!is_vmalloc_or_module_addr(dest))
		return memcpy_real(dest, src, count);
	do {
		size = min(count, PAGE_SIZE - (__pa(dest) & ~PAGE_MASK));
		if (memcpy_real(load_real_addr(dest), src, size))
			return -EFAULT;
		count -= size;
		dest += size;
		src += size;
	} while (count);
	return 0;
}

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

/*
 * Copy one page from zfcpdump "oldmem"
 *
 * For pages below 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 < sclp_get_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_from_realmem(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 HSA size. Memory below 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 hsa_end = sclp_get_hsa_size();
	unsigned long size_hsa;

	if (pfn < hsa_end >> PAGE_SHIFT) {
		size_hsa = min(size, hsa_end - (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 = copy_from_realmem(dest, src + OLDMEM_BASE, copied);
			if (rc)
				return rc;
		}
	} else {
		unsigned long hsa_end = sclp_get_hsa_size();
		if ((unsigned long) src < hsa_end) {
			copied = min(count, hsa_end - (unsigned long) src);
			rc = memcpy_hsa(dest, (unsigned long) src, copied, 0);
			if (rc)
				return rc;
		}
	}
	return copy_from_realmem(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; i < dump_save_areas.count; i++) {
		if (dump_save_areas.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; i < dump_save_areas.count; i++) {
		sa = dump_save_areas.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;
	/* If we cannot get HSA size for zfcpdump return error */
	if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp_get_hsa_size())
		return -ENODEV;
	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
58952942 MH	25	struct dump_save_areas dump_save_areas;
	26
	27	/*
	28	* Allocate and add a save area for a CPU
	29	*/
	30	struct save_area *dump_save_area_create(int cpu)
	31	{
	32	struct save_area *save_areas, save_area;
	33
	34	save_area = kmalloc(sizeof(*save_area), GFP_KERNEL);
	35	if (!save_area)
	36	return NULL;
	37	if (cpu + 1 > dump_save_areas.count) {
	38	dump_save_areas.count = cpu + 1;
	39	save_areas = krealloc(dump_save_areas.areas,
	40	dump_save_areas.count * sizeof(void *),
	41	GFP_KERNEL \| __GFP_ZERO);
	42	if (!save_areas) {
	43	kfree(save_area);
	44	return NULL;
	45	}
	46	dump_save_areas.areas = save_areas;
	47	}
	48	dump_save_areas.areas[cpu] = save_area;
	49	return save_area;
	50	}
191a2fa0 MH	51
	52	/*
	53	* Return physical address for virtual address
	54	*/
	55	static inline void load_real_addr(void addr)
	56	{
	57	unsigned long real_addr;
	58
	59	asm volatile(
	60	" lra %0,0(%1)\n"
	61	" jz 0f\n"
	62	" la %0,0\n"
	63	"0:"
	64	: "=a" (real_addr) : "a" (addr) : "cc");
	65	return (void *)real_addr;
	66	}
	67
	68	/*
4d3b0664	69	* Copy real to virtual or real memory
191a2fa0	70	*/
4d3b0664	71	static int copy_from_realmem(void dest, void src, size_t count)
191a2fa0	72	{
4d3b0664	73	unsigned long size;
4d3b0664 MH	74
	75	if (!count)
	76	return 0;
	77	if (!is_vmalloc_or_module_addr(dest))
	78	return memcpy_real(dest, src, count);
	79	do {
	80	size = min(count, PAGE_SIZE - (__pa(dest) & ~PAGE_MASK));
	81	if (memcpy_real(load_real_addr(dest), src, size))
	82	return -EFAULT;
	83	count -= size;
	84	dest += size;
	85	src += size;
	86	} while (count);
	87	return 0;
191a2fa0 MH	88	}
191a2fa0 MH	89
97b0f6f9 MH	90	/*
	91	* Pointer to ELF header in new kernel
	92	*/
	93	static void *elfcorehdr_newmem;
	94
60a0c68d	95	/*
6f79d332 MH	96	* Copy one page from zfcpdump "oldmem"
6f79d332 MH	97	*
e657d8fe	98	* For pages below HSA size memory from the HSA is copied. Otherwise
6f79d332 MH	99	* real memory copy is used.
	100	*/
	101	static ssize_t copy_oldmem_page_zfcpdump(char *buf, size_t csize,
	102	unsigned long src, int userbuf)
	103	{
	104	int rc;
	105
e657d8fe	106	if (src < sclp_get_hsa_size()) {
6f79d332 MH	107	rc = memcpy_hsa(buf, src, csize, userbuf);
	108	} else {
	109	if (userbuf)
	110	rc = copy_to_user_real((void __force __user *) buf,
	111	(void *) src, csize);
	112	else
	113	rc = memcpy_real(buf, (void *) src, csize);
	114	}
	115	return rc ? rc : csize;
	116	}
	117
	118	/*
	119	* Copy one page from kdump "oldmem"
60a0c68d MH	120	*
	121	* For the kdump reserved memory this functions performs a swap operation:
	122	* - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
	123	* - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
	124	*/
6f79d332 MH	125	static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize,
	126	unsigned long src, int userbuf)
	127
60a0c68d	128	{
191a2fa0	129	int rc;
60a0c68d	130
60a0c68d MH	131	if (src < OLDMEM_SIZE)
	132	src += OLDMEM_BASE;
	133	else if (src > OLDMEM_BASE &&
	134	src < OLDMEM_BASE + OLDMEM_SIZE)
	135	src -= OLDMEM_BASE;
	136	if (userbuf)
191a2fa0 MH	137	rc = copy_to_user_real((void __force __user *) buf,
191a2fa0 MH	138	(void *) src, csize);
60a0c68d	139	else
4d3b0664	140	rc = copy_from_realmem(buf, (void *) src, csize);
6f79d332 MH	141	return (rc == 0) ? rc : csize;
	142	}
	143
	144	/*
	145	* Copy one page from "oldmem"
	146	*/
	147	ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
	148	unsigned long offset, int userbuf)
	149	{
	150	unsigned long src;
	151
	152	if (!csize)
	153	return 0;
	154	src = (pfn << PAGE_SHIFT) + offset;
	155	if (OLDMEM_BASE)
	156	return copy_oldmem_page_kdump(buf, csize, src, userbuf);
	157	else
	158	return copy_oldmem_page_zfcpdump(buf, csize, src, userbuf);
60a0c68d MH	159	}
60a0c68d MH	160
23df79da	161	/*
6f79d332	162	* Remap "oldmem" for kdump
23df79da JW	163	*
	164	* For the kdump reserved memory this functions performs a swap operation:
	165	* [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
	166	*/
6f79d332 MH	167	static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
	168	unsigned long from, unsigned long pfn,
	169	unsigned long size, pgprot_t prot)
23df79da JW	170	{
	171	unsigned long size_old;
	172	int rc;
	173
	174	if (pfn < OLDMEM_SIZE >> PAGE_SHIFT) {
	175	size_old = min(size, OLDMEM_SIZE - (pfn << PAGE_SHIFT));
	176	rc = remap_pfn_range(vma, from,
	177	pfn + (OLDMEM_BASE >> PAGE_SHIFT),
	178	size_old, prot);
	179	if (rc \|\| size == size_old)
	180	return rc;
	181	size -= size_old;
	182	from += size_old;
	183	pfn += size_old >> PAGE_SHIFT;
	184	}
	185	return remap_pfn_range(vma, from, pfn, size, prot);
	186	}
	187
6f79d332 MH	188	/*
	189	* Remap "oldmem" for zfcpdump
	190	*
e657d8fe MH	191	* We only map available memory above HSA size. Memory below HSA size
e657d8fe MH	192	* is read on demand using the copy_oldmem_page() function.
6f79d332 MH	193	*/
	194	static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
	195	unsigned long from,
	196	unsigned long pfn,
	197	unsigned long size, pgprot_t prot)
	198	{
e657d8fe	199	unsigned long hsa_end = sclp_get_hsa_size();
6f79d332 MH	200	unsigned long size_hsa;
6f79d332 MH	201
e657d8fe MH	202	if (pfn < hsa_end >> PAGE_SHIFT) {
e657d8fe MH	203	size_hsa = min(size, hsa_end - (pfn << PAGE_SHIFT));
6f79d332 MH	204	if (size == size_hsa)
	205	return 0;
	206	size -= size_hsa;
	207	from += size_hsa;
	208	pfn += size_hsa >> PAGE_SHIFT;
	209	}
	210	return remap_pfn_range(vma, from, pfn, size, prot);
	211	}
	212
	213	/*
	214	* Remap "oldmem" for kdump or zfcpdump
	215	*/
	216	int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
	217	unsigned long pfn, unsigned long size, pgprot_t prot)
	218	{
	219	if (OLDMEM_BASE)
	220	return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
	221	else
	222	return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
	223	prot);
	224	}
	225
60a0c68d MH	226	/*
	227	* Copy memory from old kernel
	228	*/
4857d4bb	229	int copy_from_oldmem(void dest, void src, size_t count)
60a0c68d MH	230	{
	231	unsigned long copied = 0;
	232	int rc;
	233
6f79d332 MH	234	if (OLDMEM_BASE) {
	235	if ((unsigned long) src < OLDMEM_SIZE) {
	236	copied = min(count, OLDMEM_SIZE - (unsigned long) src);
4d3b0664	237	rc = copy_from_realmem(dest, src + OLDMEM_BASE, copied);
6f79d332 MH	238	if (rc)
	239	return rc;
	240	}
	241	} else {
e657d8fe MH	242	unsigned long hsa_end = sclp_get_hsa_size();
	243	if ((unsigned long) src < hsa_end) {
	244	copied = min(count, hsa_end - (unsigned long) src);
6f79d332 MH	245	rc = memcpy_hsa(dest, (unsigned long) src, copied, 0);
	246	if (rc)
	247	return rc;
	248	}
60a0c68d	249	}
4d3b0664	250	return copy_from_realmem(dest + copied, src + copied, count - copied);
60a0c68d MH	251	}
	252
	253	/*
	254	* Alloc memory and panic in case of ENOMEM
	255	*/
	256	static void *kzalloc_panic(int len)
	257	{
	258	void *rc;
	259
	260	rc = kzalloc(len, GFP_KERNEL);
	261	if (!rc)
	262	panic("s390 kdump kzalloc (%d) failed", len);
	263	return rc;
	264	}
	265
	266	/*
	267	* Get memory layout and create hole for oldmem
	268	*/
	269	static struct mem_chunk *get_memory_layout(void)
	270	{
	271	struct mem_chunk *chunk_array;
	272
	273	chunk_array = kzalloc_panic(MEMORY_CHUNKS * sizeof(struct mem_chunk));
df1bd59c	274	detect_memory_layout(chunk_array, 0);
996b4a7d	275	create_mem_hole(chunk_array, OLDMEM_BASE, OLDMEM_SIZE);
60a0c68d MH	276	return chunk_array;
	277	}
	278
	279	/*
	280	* Initialize ELF note
	281	*/
	282	static void nt_init(void buf, Elf64_Word type, void *desc, int d_len,
	283	const char *name)
	284	{
	285	Elf64_Nhdr *note;
	286	u64 len;
	287
	288	note = (Elf64_Nhdr *)buf;
	289	note->n_namesz = strlen(name) + 1;
	290	note->n_descsz = d_len;
	291	note->n_type = type;
	292	len = sizeof(Elf64_Nhdr);
	293
	294	memcpy(buf + len, name, note->n_namesz);
	295	len = roundup(len + note->n_namesz, 4);
	296
	297	memcpy(buf + len, desc, note->n_descsz);
	298	len = roundup(len + note->n_descsz, 4);
	299
	300	return PTR_ADD(buf, len);
	301	}
	302
	303	/*
	304	* Initialize prstatus note
	305	*/
	306	static void nt_prstatus(void ptr, struct save_area *sa)
	307	{
	308	struct elf_prstatus nt_prstatus;
	309	static int cpu_nr = 1;
	310
	311	memset(&nt_prstatus, 0, sizeof(nt_prstatus));
	312	memcpy(&nt_prstatus.pr_reg.gprs, sa->gp_regs, sizeof(sa->gp_regs));
	313	memcpy(&nt_prstatus.pr_reg.psw, sa->psw, sizeof(sa->psw));
	314	memcpy(&nt_prstatus.pr_reg.acrs, sa->acc_regs, sizeof(sa->acc_regs));
	315	nt_prstatus.pr_pid = cpu_nr;
	316	cpu_nr++;
	317
	318	return nt_init(ptr, NT_PRSTATUS, &nt_prstatus, sizeof(nt_prstatus),
	319	"CORE");
	320	}
	321
	322	/*
	323	* Initialize fpregset (floating point) note
	324	*/
	325	static void nt_fpregset(void ptr, struct save_area *sa)
	326	{
	327	elf_fpregset_t nt_fpregset;
	328
	329	memset(&nt_fpregset, 0, sizeof(nt_fpregset));
	330	memcpy(&nt_fpregset.fpc, &sa->fp_ctrl_reg, sizeof(sa->fp_ctrl_reg));
	331	memcpy(&nt_fpregset.fprs, &sa->fp_regs, sizeof(sa->fp_regs));
	332
	333	return nt_init(ptr, NT_PRFPREG, &nt_fpregset, sizeof(nt_fpregset),
	334	"CORE");
	335	}
	336
	337	/*
	338	* Initialize timer note
	339	*/
340	static void nt_s390_timer(void ptr, struct save_area *sa)
341	{
342	return nt_init(ptr, NT_S390_TIMER, &sa->timer, sizeof(sa->timer),
343	KEXEC_CORE_NOTE_NAME);
344	}
345
346	/*
347	* Initialize TOD clock comparator note
348	*/
349	static void nt_s390_tod_cmp(void ptr, struct save_area *sa)
350	{
351	return nt_init(ptr, NT_S390_TODCMP, &sa->clk_cmp,
352	sizeof(sa->clk_cmp), KEXEC_CORE_NOTE_NAME);
353	}
354
355	/*
356	* Initialize TOD programmable register note
357	*/
358	static void nt_s390_tod_preg(void ptr, struct save_area *sa)
359	{
360	return nt_init(ptr, NT_S390_TODPREG, &sa->tod_reg,
361	sizeof(sa->tod_reg), KEXEC_CORE_NOTE_NAME);
362	}
363
364	/*
365	* Initialize control register note
366	*/
367	static void nt_s390_ctrs(void ptr, struct save_area *sa)
368	{
369	return nt_init(ptr, NT_S390_CTRS, &sa->ctrl_regs,
370	sizeof(sa->ctrl_regs), KEXEC_CORE_NOTE_NAME);
371	}
372
373	/*
374	* Initialize prefix register note
375	*/
376	static void nt_s390_prefix(void ptr, struct save_area *sa)
377	{
378	return nt_init(ptr, NT_S390_PREFIX, &sa->pref_reg,
379	sizeof(sa->pref_reg), KEXEC_CORE_NOTE_NAME);
380	}
381
382	/*
383	* Fill ELF notes for one CPU with save area registers
384	*/
385	void fill_cpu_elf_notes(void ptr, struct save_area *sa)
386	{
387	ptr = nt_prstatus(ptr, sa);
388	ptr = nt_fpregset(ptr, sa);
389	ptr = nt_s390_timer(ptr, sa);
390	ptr = nt_s390_tod_cmp(ptr, sa);
391	ptr = nt_s390_tod_preg(ptr, sa);
392	ptr = nt_s390_ctrs(ptr, sa);
393	ptr = nt_s390_prefix(ptr, sa);
394	return ptr;
395	}
396
397	/*
398	* Initialize prpsinfo note (new kernel)
399	*/
400	static void nt_prpsinfo(void ptr)
401	{
402	struct elf_prpsinfo prpsinfo;
403
404	memset(&prpsinfo, 0, sizeof(prpsinfo));
405	prpsinfo.pr_sname = 'R';
406	strcpy(prpsinfo.pr_fname, "vmlinux");
407	return nt_init(ptr, NT_PRPSINFO, &prpsinfo, sizeof(prpsinfo),
408	KEXEC_CORE_NOTE_NAME);
409	}
410
411	/*
4857d4bb	412	* Get vmcoreinfo using lowcore->vmcore_info (new kernel)
60a0c68d	413	*/
4857d4bb	414	static void get_vmcoreinfo_old(unsigned long size)
60a0c68d MH	415	{
	416	char nt_name[11], *vmcoreinfo;
	417	Elf64_Nhdr note;
	418	void *addr;
	419
	420	if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
4857d4bb	421	return NULL;
60a0c68d MH	422	memset(nt_name, 0, sizeof(nt_name));
60a0c68d MH	423	if (copy_from_oldmem(&note, addr, sizeof(note)))
4857d4bb	424	return NULL;
60a0c68d	425	if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
4857d4bb	426	return NULL;
60a0c68d	427	if (strcmp(nt_name, "VMCOREINFO") != 0)
4857d4bb MH	428	return NULL;
4857d4bb MH	429	vmcoreinfo = kzalloc_panic(note.n_descsz);
60a0c68d	430	if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
4857d4bb MH	431	return NULL;
	432	*size = note.n_descsz;
	433	return vmcoreinfo;
	434	}
	435
	436	/*
	437	* Initialize vmcoreinfo note (new kernel)
	438	*/
	439	static void nt_vmcoreinfo(void ptr)
	440	{
	441	unsigned long size;
	442	void *vmcoreinfo;
	443
	444	vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
	445	if (!vmcoreinfo)
	446	vmcoreinfo = get_vmcoreinfo_old(&size);
	447	if (!vmcoreinfo)
60a0c68d	448	return ptr;
4857d4bb	449	return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO");
60a0c68d MH	450	}
	451
	452	/*
	453	* Initialize ELF header (new kernel)
	454	*/
	455	static void ehdr_init(Elf64_Ehdr ehdr, int mem_chunk_cnt)
	456	{
	457	memset(ehdr, 0, sizeof(*ehdr));
	458	memcpy(ehdr->e_ident, ELFMAG, SELFMAG);
	459	ehdr->e_ident[EI_CLASS] = ELFCLASS64;
	460	ehdr->e_ident[EI_DATA] = ELFDATA2MSB;
	461	ehdr->e_ident[EI_VERSION] = EV_CURRENT;
	462	memset(ehdr->e_ident + EI_PAD, 0, EI_NIDENT - EI_PAD);
	463	ehdr->e_type = ET_CORE;
	464	ehdr->e_machine = EM_S390;
	465	ehdr->e_version = EV_CURRENT;
	466	ehdr->e_phoff = sizeof(Elf64_Ehdr);
	467	ehdr->e_ehsize = sizeof(Elf64_Ehdr);
	468	ehdr->e_phentsize = sizeof(Elf64_Phdr);
	469	ehdr->e_phnum = mem_chunk_cnt + 1;
	470	return ehdr + 1;
	471	}
	472
	473	/*
	474	* Return CPU count for ELF header (new kernel)
	475	*/
	476	static int get_cpu_cnt(void)
	477	{
	478	int i, cpus = 0;
	479
58952942 MH	480	for (i = 0; i < dump_save_areas.count; i++) {
58952942 MH	481	if (dump_save_areas.areas[i]->pref_reg == 0)
60a0c68d MH	482	continue;
	483	cpus++;
	484	}
	485	return cpus;
	486	}
	487
	488	/*
	489	* Return memory chunk count for ELF header (new kernel)
	490	*/
	491	static int get_mem_chunk_cnt(void)
	492	{
	493	struct mem_chunk chunk_array, mem_chunk;
	494	int i, cnt = 0;
	495
	496	chunk_array = get_memory_layout();
	497	for (i = 0; i < MEMORY_CHUNKS; i++) {
	498	mem_chunk = &chunk_array[i];
	499	if (chunk_array[i].type != CHUNK_READ_WRITE &&
	500	chunk_array[i].type != CHUNK_READ_ONLY)
	501	continue;
	502	if (mem_chunk->size == 0)
	503	continue;
	504	cnt++;
	505	}
	506	kfree(chunk_array);
	507	return cnt;
	508	}
	509
60a0c68d MH	510	/*
	511	* Initialize ELF loads (new kernel)
	512	*/
	513	static int loads_init(Elf64_Phdr *phdr, u64 loads_offset)
	514	{
	515	struct mem_chunk chunk_array, mem_chunk;
	516	int i;
	517
	518	chunk_array = get_memory_layout();
	519	for (i = 0; i < MEMORY_CHUNKS; i++) {
	520	mem_chunk = &chunk_array[i];
	521	if (mem_chunk->size == 0)
996b4a7d	522	continue;
60a0c68d MH	523	if (chunk_array[i].type != CHUNK_READ_WRITE &&
	524	chunk_array[i].type != CHUNK_READ_ONLY)
	525	continue;
	526	else
	527	phdr->p_filesz = mem_chunk->size;
	528	phdr->p_type = PT_LOAD;
	529	phdr->p_offset = mem_chunk->addr;
	530	phdr->p_vaddr = mem_chunk->addr;
	531	phdr->p_paddr = mem_chunk->addr;
	532	phdr->p_memsz = mem_chunk->size;
	533	phdr->p_flags = PF_R \| PF_W \| PF_X;
	534	phdr->p_align = PAGE_SIZE;
	535	phdr++;
	536	}
	537	kfree(chunk_array);
	538	return i;
	539	}
	540
	541	/*
	542	* Initialize notes (new kernel)
	543	*/
	544	static void notes_init(Elf64_Phdr phdr, void *ptr, u64 notes_offset)
	545	{
	546	struct save_area *sa;
	547	void *ptr_start = ptr;
	548	int i;
	549
	550	ptr = nt_prpsinfo(ptr);
	551
58952942 MH	552	for (i = 0; i < dump_save_areas.count; i++) {
58952942 MH	553	sa = dump_save_areas.areas[i];
60a0c68d MH	554	if (sa->pref_reg == 0)
	555	continue;
	556	ptr = fill_cpu_elf_notes(ptr, sa);
	557	}
	558	ptr = nt_vmcoreinfo(ptr);
	559	memset(phdr, 0, sizeof(*phdr));
	560	phdr->p_type = PT_NOTE;
97b0f6f9	561	phdr->p_offset = notes_offset;
60a0c68d MH	562	phdr->p_filesz = (unsigned long) PTR_SUB(ptr, ptr_start);
	563	phdr->p_memsz = phdr->p_filesz;
	564	return ptr;
	565	}
	566
	567	/*
	568	* Create ELF core header (new kernel)
	569	*/
97b0f6f9	570	int elfcorehdr_alloc(unsigned long long addr, unsigned long long size)
60a0c68d MH	571	{
	572	Elf64_Phdr phdr_notes, phdr_loads;
	573	int mem_chunk_cnt;
	574	void ptr, hdr;
	575	u32 alloc_size;
	576	u64 hdr_off;
	577
6f79d332 MH	578	/* If we are not in kdump or zfcpdump mode return */
6f79d332 MH	579	if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
97b0f6f9 MH	580	return 0;
	581	/* If elfcorehdr= has been passed via cmdline, we use that one */
	582	if (elfcorehdr_addr != ELFCORE_ADDR_MAX)
	583	return 0;
e657d8fe MH	584	/* If we cannot get HSA size for zfcpdump return error */
	585	if (ipl_info.type == IPL_TYPE_FCP_DUMP && !sclp_get_hsa_size())
	586	return -ENODEV;
60a0c68d MH	587	mem_chunk_cnt = get_mem_chunk_cnt();
	588
	589	alloc_size = 0x1000 + get_cpu_cnt() * 0x300 +
	590	mem_chunk_cnt * sizeof(Elf64_Phdr);
	591	hdr = kzalloc_panic(alloc_size);
	592	/* Init elf header */
	593	ptr = ehdr_init(hdr, mem_chunk_cnt);
	594	/* Init program headers */
	595	phdr_notes = ptr;
	596	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr));
	597	phdr_loads = ptr;
	598	ptr = PTR_ADD(ptr, sizeof(Elf64_Phdr) * mem_chunk_cnt);
	599	/* Init notes */
	600	hdr_off = PTR_DIFF(ptr, hdr);
	601	ptr = notes_init(phdr_notes, ptr, ((unsigned long) hdr) + hdr_off);
	602	/* Init loads */
	603	hdr_off = PTR_DIFF(ptr, hdr);
97b0f6f9 MH	604	loads_init(phdr_loads, hdr_off);
	605	*addr = (unsigned long long) hdr;
	606	elfcorehdr_newmem = hdr;
	607	*size = (unsigned long long) hdr_off;
	608	BUG_ON(elfcorehdr_size > alloc_size);
	609	return 0;
60a0c68d MH	610	}
	611
	612	/*
97b0f6f9	613	* Free ELF core header (new kernel)
60a0c68d	614	*/
97b0f6f9	615	void elfcorehdr_free(unsigned long long addr)
60a0c68d	616	{
97b0f6f9 MH	617	if (!elfcorehdr_newmem)
	618	return;
	619	kfree((void *)(unsigned long)addr);
	620	}
	621
	622	/*
	623	* Read from ELF header
	624	*/
	625	ssize_t elfcorehdr_read(char buf, size_t count, u64 ppos)
	626	{
	627	void src = (void )(unsigned long)*ppos;
	628
	629	src = elfcorehdr_newmem ? src : src - OLDMEM_BASE;
	630	memcpy(buf, src, count);
	631	*ppos += count;
	632	return count;
60a0c68d MH	633	}
60a0c68d MH	634
97b0f6f9 MH	635	/*
	636	* Read from ELF notes data
	637	*/
	638	ssize_t elfcorehdr_read_notes(char buf, size_t count, u64 ppos)
	639	{
	640	void src = (void )(unsigned long)*ppos;
	641	int rc;
	642
	643	if (elfcorehdr_newmem) {
	644	memcpy(buf, src, count);
	645	} else {
	646	rc = copy_from_oldmem(buf, src, count);
	647	if (rc)
	648	return rc;
	649	}
	650	*ppos += count;
	651	return count;
	652	}