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Subject[patch v3 5/8] s390: kdump backend code
From: Michael Holzheu <holzheu@linux.vnet.ibm.com>

This patch provides the architecture specific part of the s390 kdump
support.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
---
arch/s390/Kconfig | 10 +
arch/s390/include/asm/ipl.h | 1
arch/s390/include/asm/kexec.h | 3
arch/s390/include/asm/setup.h | 9 +
arch/s390/kernel/Makefile | 1
arch/s390/kernel/crash_dump.c | 39 +++++
arch/s390/kernel/head.S | 16 ++
arch/s390/kernel/head_kdump.S | 116 +++++++++++++++++
arch/s390/kernel/ipl.c | 4
arch/s390/kernel/machine_kexec.c | 255 +++++++++++++++++++++++++++++++++++++++
arch/s390/kernel/mem_detect.c | 69 ++++++++++
arch/s390/kernel/setup.c | 190 +++++++++++++++++++++++++++++
arch/s390/mm/vmem.c | 3
13 files changed, 716 insertions(+)
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -568,6 +568,16 @@ config KEXEC
current kernel, and to start another kernel. It is like a reboot
but is independent of hardware/microcode support.

+config CRASH_DUMP
+ bool "kernel crash dumps"
+ depends on 64BIT
+ help
+ Generate crash dump after being started by kexec.
+ Crash dump kernels are loaded in the main kernel with kexec-tools
+ into a specially reserved region and then later executed after
+ a crash by kdump/kexec.
+ For more details see Documentation/kdump/kdump.txt
+
config ZFCPDUMP
def_bool n
prompt "zfcpdump support"
--- a/arch/s390/include/asm/ipl.h
+++ b/arch/s390/include/asm/ipl.h
@@ -168,5 +168,6 @@ enum diag308_rc {

extern int diag308(unsigned long subcode, void *addr);
extern void diag308_reset(void);
+extern void store_status(void);

#endif /* _ASM_S390_IPL_H */
--- a/arch/s390/include/asm/kexec.h
+++ b/arch/s390/include/asm/kexec.h
@@ -30,6 +30,9 @@
/* Not more than 2GB */
#define KEXEC_CONTROL_MEMORY_LIMIT (1UL<<31)

+/* Maximum address we can use for the crash control pages */
+#define KEXEC_CRASH_CONTROL_MEMORY_LIMIT (-1UL)
+
/* Allocate one page for the pdp and the second for the code */
#define KEXEC_CONTROL_PAGE_SIZE 4096

--- a/arch/s390/include/asm/setup.h
+++ b/arch/s390/include/asm/setup.h
@@ -30,11 +30,15 @@
#define IPL_DEVICE (*(unsigned long *) (0x10400))
#define INITRD_START (*(unsigned long *) (0x10408))
#define INITRD_SIZE (*(unsigned long *) (0x10410))
+#define OLDMEM_BASE (*(unsigned long *) (0x10418))
+#define OLDMEM_SIZE (*(unsigned long *) (0x10420))
#endif /* __s390x__ */
#define COMMAND_LINE ((char *) (0x10480))

#define CHUNK_READ_WRITE 0
#define CHUNK_READ_ONLY 1
+#define CHUNK_OLDMEM 4
+#define CHUNK_CRASHK 5

struct mem_chunk {
unsigned long addr;
@@ -48,6 +52,8 @@ extern int memory_end_set;
extern unsigned long memory_end;

void detect_memory_layout(struct mem_chunk chunk[]);
+void create_mem_hole(struct mem_chunk memory_chunk[], unsigned long addr,
+ unsigned long size, int type);

#define PRIMARY_SPACE_MODE 0
#define ACCESS_REGISTER_MODE 1
@@ -106,6 +112,7 @@ extern unsigned int user_mode;
#endif /* __s390x__ */

#define ZFCPDUMP_HSA_SIZE (32UL<<20)
+#define ZFCPDUMP_HSA_SIZE_MAX (64UL<<20)

/*
* Console mode. Override with conmode=
@@ -138,6 +145,8 @@ extern char kernel_nss_name[];
#define IPL_DEVICE 0x10400
#define INITRD_START 0x10408
#define INITRD_SIZE 0x10410
+#define OLDMEM_BASE 0x10418
+#define OLDMEM_SIZE 0x10420
#endif /* __s390x__ */
#define COMMAND_LINE 0x10480

--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_FUNCTION_TRACER) += $(if $(
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o
+obj-$(CONFIG_CRASH_DUMP) += crash_dump.o

# Kexec part
S390_KEXEC_OBJS := machine_kexec.o crash.o
--- /dev/null
+++ b/arch/s390/kernel/crash_dump.c
@@ -0,0 +1,39 @@
+/*
+ * 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>
+
+/*
+ * 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;
+ int rc;
+
+ 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)
+ rc = copy_to_user_real((void __user *) buf, (void *) src,
+ csize);
+ else
+ rc = memcpy_real(buf, (void *) src, csize);
+ return rc < 0 ? rc : csize;
+}
--- a/arch/s390/kernel/head.S
+++ b/arch/s390/kernel/head.S
@@ -449,10 +449,22 @@ ENTRY(start)
#
.org 0x10000
ENTRY(startup)
+ j .Lep_startup_normal
+ .org 0x10008
+ .ascii "S390EP"
+ .byte 0x00,0x01
+#
+# kdump startup-code at 0x10010, running in 64 bit absolute addressing mode
+#
+ .org 0x10010
+ENTRY(startup_kdump)
+ j .Lep_startup_kdump
+.Lep_startup_normal:
basr %r13,0 # get base
.LPG0:
xc 0x200(256),0x200 # partially clear lowcore
xc 0x300(256),0x300
+ xc 0xe00(256),0xe00
stck __LC_LAST_UPDATE_CLOCK
spt 5f-.LPG0(%r13)
mvc __LC_LAST_UPDATE_TIMER(8),5f-.LPG0(%r13)
@@ -534,6 +546,8 @@ ENTRY(startup)
.align 8
5: .long 0x7fffffff,0xffffffff

+#include "head_kdump.S"
+
#
# params at 10400 (setup.h)
#
@@ -541,6 +555,8 @@ ENTRY(startup)
.long 0,0 # IPL_DEVICE
.long 0,0 # INITRD_START
.long 0,0 # INITRD_SIZE
+ .long 0,0 # OLDMEM_BASE
+ .long 0,0 # OLDMEM_SIZE

.org COMMAND_LINE
.byte "root=/dev/ram0 ro"
--- /dev/null
+++ b/arch/s390/kernel/head_kdump.S
@@ -0,0 +1,116 @@
+/*
+ * S390 kdump lowlevel functions (new kernel)
+ *
+ * Copyright IBM Corp. 2011
+ * Author(s): Michael Holzheu <holzheu@linux.vnet.ibm.com>
+ */
+
+#define DATAMOVER_ADDR 0x4000
+#define COPY_PAGE_ADDR 0x6000
+
+#ifdef CONFIG_CRASH_DUMP
+
+#
+# kdump entry (new kernel - not yet relocated)
+#
+# Note: This code has to be position independent
+#
+
+.align 2
+.Lep_startup_kdump:
+ basr %r13,0
+.Lbase:
+ larl %r2,.Lbase_addr # Check, if we have been
+ lg %r2,0(%r2) # already relocated:
+ clgr %r2,%r13 #
+ jne .Lrelocate # No : Start data mover
+ lghi %r2,0 # Yes: Start kdump kernel
+ brasl %r14,startup_kdump_relocated
+
+.Lrelocate:
+ larl %r4,startup
+ lg %r2,0x418(%r4) # Get kdump base
+ lg %r3,0x420(%r4) # Get kdump size
+
+ larl %r10,.Lcopy_start # Source of data mover
+ lghi %r8,DATAMOVER_ADDR # Target of data mover
+ mvc 0(256,%r8),0(%r10) # Copy data mover code
+
+ agr %r8,%r2 # Copy data mover to
+ mvc 0(256,%r8),0(%r10) # reserved mem
+
+ lghi %r14,DATAMOVER_ADDR # Jump to copied data mover
+ basr %r14,%r14
+.Lbase_addr:
+ .quad .Lbase
+
+#
+# kdump data mover code (runs at address DATAMOVER_ADDR)
+#
+# r2: kdump base address
+# r3: kdump size
+#
+.Lcopy_start:
+ basr %r13,0 # Base
+0:
+ lgr %r11,%r2 # Save kdump base address
+ lgr %r12,%r2
+ agr %r12,%r3 # Compute kdump end address
+
+ lghi %r5,0
+ lghi %r10,COPY_PAGE_ADDR # Load copy page address
+1:
+ mvc 0(256,%r10),0(%r5) # Copy old kernel to tmp
+ mvc 0(256,%r5),0(%r11) # Copy new kernel to old
+ mvc 0(256,%r11),0(%r10) # Copy tmp to new
+ aghi %r11,256
+ aghi %r5,256
+ clgr %r11,%r12
+ jl 1b
+
+ lg %r14,.Lstartup_kdump-0b(%r13)
+ basr %r14,%r14 # Start relocated kernel
+.Lstartup_kdump:
+ .long 0x00000000,0x00000000 + startup_kdump_relocated
+.Lcopy_end:
+
+#
+# Startup of kdump (relocated new kernel)
+#
+.align 2
+startup_kdump_relocated:
+ basr %r13,0
+0:
+ mvc 0(8,%r0),.Lrestart_psw-0b(%r13) # Setup restart PSW
+ mvc 464(16,%r0),.Lpgm_psw-0b(%r13) # Setup pgm check PSW
+ lhi %r1,1 # Start new kernel
+ diag %r1,%r1,0x308 # with diag 308
+
+.Lno_diag308: # No diag 308
+ sam31 # Switch to 31 bit addr mode
+ sr %r1,%r1 # Erase register r1
+ sr %r2,%r2 # Erase register r2
+ sigp %r1,%r2,0x12 # Switch to 31 bit arch mode
+ lpsw 0 # Start new kernel...
+.align 8
+.Lrestart_psw:
+ .long 0x00080000,0x80000000 + startup
+.Lpgm_psw:
+ .quad 0x0000000180000000,0x0000000000000000 + .Lno_diag308
+#else
+.align 2
+.Lep_startup_kdump:
+#ifdef CONFIG_64BIT
+ larl %r13,startup_kdump_crash
+ lpswe 0(%r13)
+.align 8
+startup_kdump_crash:
+ .quad 0x0002000080000000,0x0000000000000000 + startup_kdump_crash
+#else
+ basr %r13,0
+0: lpsw startup_kdump_crash-0b(%r13)
+.align 8
+startup_kdump_crash:
+ .long 0x000a0000,0x00000000 + startup_kdump_crash
+#endif /* CONFIG_64BIT */
+#endif /* CONFIG_CRASH_DUMP */
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -16,6 +16,7 @@
#include <linux/ctype.h>
#include <linux/fs.h>
#include <linux/gfp.h>
+#include <linux/crash_dump.h>
#include <asm/ipl.h>
#include <asm/smp.h>
#include <asm/setup.h>
@@ -1738,6 +1739,9 @@ static struct kobj_attribute on_restart_
void do_restart(void)
{
smp_send_stop();
+#ifdef CONFIG_CRASH_DUMP
+ crash_kexec(NULL);
+#endif
on_restart_trigger.action->fn(&on_restart_trigger);
stop_run(&on_restart_trigger);
}
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -21,12 +21,260 @@
#include <asm/smp.h>
#include <asm/reset.h>
#include <asm/ipl.h>
+#include <asm/diag.h>

typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);

extern const unsigned char relocate_kernel[];
extern const unsigned long long relocate_kernel_len;

+#ifdef CONFIG_CRASH_DUMP
+
+#define ROUNDUP(x, y) ((((x) + ((y) - 1)) / (y)) * (y))
+#define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
+
+#ifndef NT_FPREGSET
+#define NT_FPREGSET 2
+#endif
+
+/*
+ * fpregset ELF Note
+ */
+struct nt_fpregset_64 {
+ u32 fpc;
+ u32 pad;
+ u64 fprs[16];
+} __packed;
+
+/*
+ * 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)
+{
+ struct nt_fpregset_64 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_FPREGSET, &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);
+}
+
+/*
+ * Final empty node
+ */
+static void nt_final(void *ptr)
+{
+ memset(ptr, 0, sizeof(struct elf_note));
+}
+
+/*
+ * Add create ELF notes for CPU
+ */
+static void add_elf_notes(int cpu)
+{
+ struct save_area *sa = (void *) 4608 + store_prefix();
+ void *ptr;
+
+ memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa));
+ ptr = (u64 *) per_cpu_ptr(crash_notes, cpu);
+ 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);
+ nt_final(ptr);
+}
+
+/*
+ * Store status of next available physical CPU
+ */
+static int store_status_next(int start_cpu, int this_cpu)
+{
+ struct save_area *sa = (void *) 4608 + store_prefix();
+ int cpu, rc;
+
+ for (cpu = start_cpu; cpu < 65536; cpu++) {
+ if (cpu == this_cpu)
+ continue;
+ do {
+ rc = raw_sigp(cpu, sigp_stop_and_store_status);
+ } while (rc == sigp_busy);
+ if (rc != sigp_order_code_accepted)
+ continue;
+ if (sa->pref_reg)
+ return cpu;
+ }
+ return -1;
+}
+
+/*
+ * Initialize CPU ELF notes
+ */
+void setup_regs(void)
+{
+ int cpu, this_cpu, phys_cpu = 0, first = 1;
+
+ this_cpu = stap();
+
+ store_status();
+ if (!S390_lowcore.prefixreg_save_area)
+ first = 0;
+ for_each_online_cpu(cpu) {
+ if (first) {
+ add_elf_notes(cpu);
+ first = 0;
+ continue;
+ }
+ phys_cpu = store_status_next(phys_cpu, this_cpu);
+ if (phys_cpu == -1)
+ return;
+ add_elf_notes(cpu);
+ phys_cpu++;
+ }
+}
+
+/*
+ * S390 version: Currently we do not support freeing crashkernel memory
+ */
+void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
+{
+ return;
+}
+
+/*
+ * S390 version: Just do real copy of segment
+ */
+int kimage_load_crash_segment(struct kimage *image,
+ struct kexec_segment *segment)
+{
+ return copy_from_user_real((void *) segment->mem, segment->buf,
+ segment->bufsz);
+}
+
+/*
+ * Start kdump
+ */
+static void __machine_kdump(void *image)
+{
+ int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;
+
+ pfault_fini();
+ s390_reset_system();
+ __load_psw_mask(PSW_BASE_BITS | PSW_DEFAULT_KEY);
+ setup_regs();
+ start_kdump(1);
+ disabled_wait((unsigned long) __builtin_return_address(0));
+}
+
+#endif
+
+/*
+ * Give back memory to hypervisor before new kdump is loaded
+ */
+static int machine_kexec_prepare_kdump(void)
+{
+#ifdef CONFIG_CRASH_DUMP
+ if (MACHINE_IS_VM)
+ diag10_range(PFN_DOWN(crashk_res.start),
+ PFN_DOWN(crashk_res.end - crashk_res.start + 1));
+ return 0;
+#else
+ return -EINVAL;
+#endif
+}
+
int machine_kexec_prepare(struct kimage *image)
{
void *reboot_code_buffer;
@@ -35,6 +283,9 @@ int machine_kexec_prepare(struct kimage
if (ipl_flags & IPL_NSS_VALID)
return -ENOSYS;

+ if (image->type == KEXEC_TYPE_CRASH)
+ return machine_kexec_prepare_kdump();
+
/* We don't support anything but the default image type for now. */
if (image->type != KEXEC_TYPE_DEFAULT)
return -EINVAL;
@@ -73,6 +324,10 @@ static void __machine_kexec(void *data)
void machine_kexec(struct kimage *image)
{
tracer_disable();
+#ifdef CONFIG_CRASH_DUMP
+ if (image->type == KEXEC_TYPE_CRASH)
+ smp_switch_to_ipl_cpu(__machine_kdump, image);
+#endif
smp_send_stop();
smp_switch_to_ipl_cpu(__machine_kexec, image);
}
--- a/arch/s390/kernel/mem_detect.c
+++ b/arch/s390/kernel/mem_detect.c
@@ -62,3 +62,72 @@ void detect_memory_layout(struct mem_chu
arch_local_irq_restore(flags);
}
EXPORT_SYMBOL(detect_memory_layout);
+
+/*
+ * Create memory hole with given address, size, and type
+ */
+void create_mem_hole(struct mem_chunk chunks[], unsigned long addr,
+ unsigned long size, int type)
+{
+ unsigned long start, end, new_size;
+ int i;
+
+ for (i = 0; i < MEMORY_CHUNKS; i++) {
+ if (chunks[i].size == 0)
+ continue;
+ if (addr + size < chunks[i].addr)
+ continue;
+ if (addr >= chunks[i].addr + chunks[i].size)
+ continue;
+ start = max(addr, chunks[i].addr);
+ end = min(addr + size, chunks[i].addr + chunks[i].size);
+ new_size = end - start;
+ if (new_size == 0)
+ continue;
+ if (start == chunks[i].addr &&
+ end == chunks[i].addr + chunks[i].size) {
+ /* Remove chunk */
+ chunks[i].type = type;
+ } else if (start == chunks[i].addr) {
+ /* Make chunk smaller at start */
+ if (i >= MEMORY_CHUNKS - 1)
+ panic("Unable to create memory hole");
+ memmove(&chunks[i + 1], &chunks[i],
+ sizeof(struct mem_chunk) *
+ (MEMORY_CHUNKS - (i + 1)));
+ chunks[i + 1].addr = chunks[i].addr + new_size;
+ chunks[i + 1].size = chunks[i].size - new_size;
+ chunks[i].size = new_size;
+ chunks[i].type = type;
+ i += 1;
+ } else if (end == chunks[i].addr + chunks[i].size) {
+ /* Make chunk smaller at end */
+ if (i >= MEMORY_CHUNKS - 1)
+ panic("Unable to create memory hole");
+ memmove(&chunks[i + 1], &chunks[i],
+ sizeof(struct mem_chunk) *
+ (MEMORY_CHUNKS - (i + 1)));
+ chunks[i + 1].addr = start;
+ chunks[i + 1].size = new_size;
+ chunks[i + 1].type = type;
+ chunks[i].size -= new_size;
+ i += 1;
+ } else {
+ /* Create memory hole */
+ if (i >= MEMORY_CHUNKS - 2)
+ panic("Unable to create memory hole");
+ memmove(&chunks[i + 2], &chunks[i],
+ sizeof(struct mem_chunk) *
+ (MEMORY_CHUNKS - (i + 2)));
+ chunks[i + 1].addr = addr;
+ chunks[i + 1].size = size;
+ chunks[i + 1].type = type;
+ chunks[i + 2].addr = addr + size;
+ chunks[i + 2].size =
+ chunks[i].addr + chunks[i].size - (addr + size);
+ chunks[i + 2].type = chunks[i].type;
+ chunks[i].size = addr - chunks[i].addr;
+ i += 2;
+ }
+ }
+}
--- a/arch/s390/kernel/setup.c
+++ b/arch/s390/kernel/setup.c
@@ -42,6 +42,9 @@
#include <linux/reboot.h>
#include <linux/topology.h>
#include <linux/ftrace.h>
+#include <linux/kexec.h>
+#include <linux/crash_dump.h>
+#include <linux/memory.h>

#include <asm/ipl.h>
#include <asm/uaccess.h>
@@ -57,6 +60,7 @@
#include <asm/ebcdic.h>
#include <asm/compat.h>
#include <asm/kvm_virtio.h>
+#include <asm/diag.h>

long psw_kernel_bits = (PSW_BASE_BITS | PSW_MASK_DAT | PSW_ASC_PRIMARY |
PSW_MASK_MCHECK | PSW_DEFAULT_KEY);
@@ -435,6 +439,9 @@ static void __init setup_resources(void)
for (i = 0; i < MEMORY_CHUNKS; i++) {
if (!memory_chunk[i].size)
continue;
+ if (memory_chunk[i].type == CHUNK_OLDMEM ||
+ memory_chunk[i].type == CHUNK_CRASHK)
+ continue;
res = alloc_bootmem_low(sizeof(*res));
res->flags = IORESOURCE_BUSY | IORESOURCE_MEM;
switch (memory_chunk[i].type) {
@@ -479,6 +486,7 @@ static void __init setup_memory_end(void
unsigned long max_mem;
int i;

+
#ifdef CONFIG_ZFCPDUMP
if (ipl_info.type == IPL_TYPE_FCP_DUMP) {
memory_end = ZFCPDUMP_HSA_SIZE;
@@ -550,6 +558,173 @@ static void __init setup_restart_psw(voi
copy_to_absolute_zero(&S390_lowcore.restart_psw, &psw, sizeof(psw));
}

+#ifdef CONFIG_CRASH_DUMP
+
+/*
+ * Find suitable location for crashkernel memory
+ */
+static unsigned long __init find_crash_base(unsigned long crash_size)
+{
+ unsigned long crash_base;
+ struct mem_chunk *chunk;
+ int i;
+
+ if (is_kdump_kernel() && (crash_size == OLDMEM_SIZE))
+ return OLDMEM_BASE;
+
+ for (i = MEMORY_CHUNKS - 1; i >= 0; i--) {
+ chunk = &memory_chunk[i];
+ if (chunk->size == 0)
+ continue;
+ if (chunk->type != CHUNK_READ_WRITE)
+ continue;
+ if (chunk->size < crash_size)
+ continue;
+ crash_base = max(chunk->addr, crash_size);
+ crash_base = max(crash_base, ZFCPDUMP_HSA_SIZE_MAX);
+ crash_base = max(crash_base, (unsigned long) INITRD_START +
+ INITRD_SIZE);
+ crash_base = PAGE_ALIGN(crash_base);
+ if (crash_base >= chunk->addr + chunk->size)
+ continue;
+ if (chunk->addr + chunk->size - crash_base < crash_size)
+ continue;
+ crash_base = chunk->size - crash_size;
+ return crash_base;
+ }
+ return 0;
+}
+
+/*
+ * Check if crash_base and crash_size is valid
+ */
+static int __init verify_crash_base(unsigned long crash_base,
+ unsigned long crash_size)
+{
+ struct mem_chunk *chunk;
+ int i;
+
+ /*
+ * Because we do the swap to zero, we must have at least 'crash_size'
+ * bytes free space before crash_base
+ */
+ if (crash_size > crash_base)
+ return -EINVAL;
+
+ /* First memory chunk must be at least crash_size */
+ if (memory_chunk[0].size < crash_size)
+ return -EINVAL;
+
+ /* Check if we fit into the respective memory chunk */
+ for (i = 0; i < MEMORY_CHUNKS; i++) {
+ chunk = &memory_chunk[i];
+ if (chunk->size == 0)
+ continue;
+ if (crash_base < chunk->addr)
+ continue;
+ if (crash_base >= chunk->addr + chunk->size)
+ continue;
+ /* we have found the memory chunk */
+ if (crash_base + crash_size > chunk->addr + chunk->size)
+ return -EINVAL;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+/*
+ * Reserve kdump memory by creating a memory hole in the mem_chunk array
+ */
+static void __init reserve_kdump_bootmem(unsigned long addr, unsigned long size,
+ int type)
+{
+ create_mem_hole(memory_chunk, addr, size, type);
+}
+
+/*
+ * When kdump is enabled, we have to ensure that no memory from
+ * the area [0 - crashkernel memory size] is set offline
+ */
+static int kdump_mem_notifier(struct notifier_block *nb,
+ unsigned long action, void *data)
+{
+ struct memory_notify *arg = data;
+
+ if (arg->start_pfn >= PFN_DOWN(crashk_res.end - crashk_res.start + 1))
+ return NOTIFY_OK;
+ return NOTIFY_BAD;
+}
+
+static struct notifier_block kdump_mem_nb = {
+ .notifier_call = kdump_mem_notifier,
+};
+
+#endif
+
+/*
+ * Make sure that oldmem, where the dump is stored, is protected
+ */
+static void reserve_oldmem(void)
+{
+#ifdef CONFIG_CRASH_DUMP
+ if (!is_kdump_kernel())
+ return;
+
+ reserve_kdump_bootmem(OLDMEM_BASE, OLDMEM_SIZE, CHUNK_OLDMEM);
+ reserve_kdump_bootmem(OLDMEM_SIZE, memory_end - OLDMEM_SIZE,
+ CHUNK_OLDMEM);
+ if (OLDMEM_BASE + OLDMEM_SIZE == real_memory_size)
+ saved_max_pfn = PFN_DOWN(OLDMEM_BASE) - 1;
+ else
+ saved_max_pfn = PFN_DOWN(real_memory_size) - 1;
+#endif
+}
+
+/*
+ * Reserve memory for kdump kernel to be loaded with kexec
+ */
+static void __init reserve_crashkernel(void)
+{
+#ifdef CONFIG_CRASH_DUMP
+ unsigned long long crash_base, crash_size;
+ int rc;
+
+ rc = parse_crashkernel(boot_command_line, memory_end, &crash_size,
+ &crash_base);
+ if (rc || crash_size == 0)
+ return;
+ crash_base = PAGE_ALIGN(crash_base);
+ crash_size = PAGE_ALIGN(crash_size);
+ if (register_memory_notifier(&kdump_mem_nb))
+ return;
+ if (!crash_base)
+ crash_base = find_crash_base(crash_size);
+ if (!crash_base) {
+ pr_info("crashkernel reservation failed: %s\n",
+ "No suitable area found");
+ unregister_memory_notifier(&kdump_mem_nb);
+ return;
+ }
+ if (verify_crash_base(crash_base, crash_size)) {
+ pr_info("crashkernel reservation failed: %s\n",
+ "Invalid memory range specified");
+ unregister_memory_notifier(&kdump_mem_nb);
+ return;
+ }
+ if (!is_kdump_kernel() && MACHINE_IS_VM)
+ diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
+ crashk_res.start = crash_base;
+ crashk_res.end = crash_base + crash_size - 1;
+ insert_resource(&iomem_resource, &crashk_res);
+ reserve_kdump_bootmem(crashk_res.start,
+ crashk_res.end - crashk_res.start + 1,
+ CHUNK_CRASHK);
+ pr_info("Reserving %lluMB of memory at %lluMB "
+ "for crashkernel (System RAM: %luMB)\n",
+ crash_size >> 20, crash_base >> 20, memory_end >> 20);
+#endif
+}
+
static void __init
setup_memory(void)
{
@@ -580,6 +755,14 @@ setup_memory(void)
if (PFN_PHYS(start_pfn) + bmap_size > INITRD_START) {
start = PFN_PHYS(start_pfn) + bmap_size + PAGE_SIZE;

+#ifdef CONFIG_CRASH_DUMP
+ if (is_kdump_kernel()) {
+ /* Move initrd behind kdump oldmem */
+ if (start + INITRD_SIZE > OLDMEM_BASE &&
+ start < OLDMEM_BASE + OLDMEM_SIZE)
+ start = OLDMEM_BASE + OLDMEM_SIZE;
+ }
+#endif
if (start + INITRD_SIZE > memory_end) {
pr_err("initrd extends beyond end of "
"memory (0x%08lx > 0x%08lx) "
@@ -644,6 +827,11 @@ setup_memory(void)
reserve_bootmem(start_pfn << PAGE_SHIFT, bootmap_size,
BOOTMEM_DEFAULT);

+#ifdef CONFIG_CRASH_DUMP
+ if (is_kdump_kernel())
+ reserve_bootmem(elfcorehdr_addr - OLDMEM_BASE,
+ PAGE_ALIGN(elfcorehdr_size), BOOTMEM_DEFAULT);
+#endif
#ifdef CONFIG_BLK_DEV_INITRD
if (INITRD_START && INITRD_SIZE) {
if (INITRD_START + INITRD_SIZE <= memory_end) {
@@ -812,6 +1000,8 @@ setup_arch(char **cmdline_p)
setup_ipl();
setup_memory_end();
setup_addressing_mode();
+ reserve_oldmem();
+ reserve_crashkernel();
setup_memory();
setup_resources();
setup_restart_psw();
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -335,6 +335,9 @@ void __init vmem_map_init(void)
ro_start = ((unsigned long)&_stext) & PAGE_MASK;
ro_end = PFN_ALIGN((unsigned long)&_eshared);
for (i = 0; i < MEMORY_CHUNKS && memory_chunk[i].size > 0; i++) {
+ if (memory_chunk[i].type == CHUNK_CRASHK ||
+ memory_chunk[i].type == CHUNK_OLDMEM)
+ continue;
start = memory_chunk[i].addr;
end = memory_chunk[i].addr + memory_chunk[i].size;
if (start >= ro_end || end <= ro_start)


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