[S390] s390: hibernation support for s390

This patch introduces the hibernation backend support to the
s390 architecture. Now it is possible to suspend a mainframe Linux
guest using the following command:

echo disk > /sys/power/state

Signed-off-by: Hans-Joachim Picht <hans@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

12 files changed, 375 insertions, 27 deletions

diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 99dc3ded6b49..a14dba0e4d67 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -348,6 +348,9 @@ config ARCH_ENABLE_MEMORY_HOTPLUG
 config ARCH_ENABLE_MEMORY_HOTREMOVE
         def_bool y
 
+config ARCH_HIBERNATION_POSSIBLE
+       def_bool y if 64BIT
+
 source "mm/Kconfig"
 
 comment "I/O subsystem configuration"
@@ -592,6 +595,12 @@ config SECCOMP
 
 endmenu
 
+menu "Power Management"
+
+source "kernel/power/Kconfig"
+
+endmenu
+
 source "net/Kconfig"
 
 config PCMCIA
diff --git a/arch/s390/Makefile b/arch/s390/Makefile
index 578c61f15a4b..0ff387cebf88 100644
--- a/arch/s390/Makefile
+++ b/arch/s390/Makefile
@@ -88,7 +88,9 @@ LDFLAGS_vmlinux := -e start
 head-y          := arch/s390/kernel/head.o arch/s390/kernel/init_task.o
 
 core-y          += arch/s390/mm/ arch/s390/kernel/ arch/s390/crypto/ \
-                   arch/s390/appldata/ arch/s390/hypfs/ arch/s390/kvm/
+                   arch/s390/appldata/ arch/s390/hypfs/ arch/s390/kvm/ \
+                   arch/s390/power/
+
 libs-y          += arch/s390/lib/
 drivers-y       += drivers/s390/
 drivers-$(CONFIG_MATHEMU) += arch/s390/math-emu/
diff --git a/arch/s390/include/asm/suspend.h b/arch/s390/include/asm/suspend.h
new file mode 100644
index 000000000000..dc75c616eafe
--- /dev/null
+++ b/arch/s390/include/asm/suspend.h
@@ -0,0 +1,10 @@
+#ifndef __ASM_S390_SUSPEND_H
+#define __ASM_S390_SUSPEND_H
+
+static inline int arch_prepare_suspend(void)
+{
+        return 0;
+}
+
+#endif
+
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index 3a8b26eb1f2e..4fb83c1cdb77 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -1,11 +1,7 @@
 /*
- *  include/asm-s390/system.h
+ * Copyright IBM Corp. 1999, 2009
  *
- *  S390 version
- *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
- *    Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com),
- *
- *  Derived from "include/asm-i386/system.h"
+ * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  */
 
 #ifndef __ASM_SYSTEM_H
@@ -469,6 +465,20 @@ extern psw_t sysc_restore_trace_psw;
 extern psw_t io_restore_trace_psw;
 #endif
 
+static inline int tprot(unsigned long addr)
+{
+        int rc = -EFAULT;
+
+        asm volatile(
+                "       tprot   0(%1),0\n"
+                "0:     ipm     %0\n"
+                "       srl     %0,28\n"
+                "1:\n"
+                EX_TABLE(0b,1b)
+                : "+d" (rc) : "a" (addr) : "cc");
+        return rc;
+}
+
 #endif /* __KERNEL__ */
 
 #endif
diff --git a/arch/s390/kernel/early.c b/arch/s390/kernel/early.c
index fb263736826c..f9b144049dc9 100644
--- a/arch/s390/kernel/early.c
+++ b/arch/s390/kernel/early.c
@@ -1,7 +1,7 @@
 /*
  *  arch/s390/kernel/early.c
  *
- *    Copyright IBM Corp. 2007
+ *    Copyright IBM Corp. 2007, 2009
  *    Author(s): Hongjie Yang <hongjie@us.ibm.com>,
  *               Heiko Carstens <heiko.carstens@de.ibm.com>
  */
@@ -210,7 +210,7 @@ static noinline __init void detect_machine_type(void)
                 machine_flags |= MACHINE_FLAG_VM;
 }
 
-static __init void early_pgm_check_handler(void)
+static void early_pgm_check_handler(void)
 {
         unsigned long addr;
         const struct exception_table_entry *fixup;
@@ -222,7 +222,7 @@ static __init void early_pgm_check_handler(void)
         S390_lowcore.program_old_psw.addr = fixup->fixup | PSW_ADDR_AMODE;
 }
 
-static noinline __init void setup_lowcore_early(void)
+void setup_lowcore_early(void)
 {
         psw_t psw;
 
diff --git a/arch/s390/kernel/mem_detect.c b/arch/s390/kernel/mem_detect.c
index 9872999c66d1..559af0d07878 100644
--- a/arch/s390/kernel/mem_detect.c
+++ b/arch/s390/kernel/mem_detect.c
@@ -1,6 +1,7 @@
 /*
- *    Copyright IBM Corp. 2008
- *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ * Copyright IBM Corp. 2008, 2009
+ *
+ * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
  */
 
 #include <linux/kernel.h>
@@ -9,20 +10,6 @@
 #include <asm/sclp.h>
 #include <asm/setup.h>
 
-static inline int tprot(unsigned long addr)
-{
-        int rc = -EFAULT;
-
-        asm volatile(
-                "       tprot   0(%1),0\n"
-                "0:     ipm     %0\n"
-                "       srl     %0,28\n"
-                "1:\n"
-                EX_TABLE(0b,1b)
-                : "+d" (rc) : "a" (addr) : "cc");
-        return rc;
-}
-
 #define ADDR2G (1ULL << 31)
 
 static void find_memory_chunks(struct mem_chunk chunk[])
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index cc8c484984e3..fd8e3111a4e8 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -1,7 +1,7 @@
 /*
  *  arch/s390/kernel/smp.c
  *
- *    Copyright IBM Corp. 1999,2007
+ *    Copyright IBM Corp. 1999, 2009
  *    Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com),
  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
  *               Heiko Carstens (heiko.carstens@de.ibm.com)
@@ -1031,6 +1031,42 @@ out:
 static SYSDEV_CLASS_ATTR(dispatching, 0644, dispatching_show,
                          dispatching_store);
 
+/*
+ * If the resume kernel runs on another cpu than the suspended kernel,
+ * we have to switch the cpu IDs in the logical map.
+ */
+void smp_switch_boot_cpu_in_resume(u32 resume_phys_cpu_id,
+                                   struct _lowcore *suspend_lowcore)
+{
+        int cpu, suspend_cpu_id, resume_cpu_id;
+        u32 suspend_phys_cpu_id;
+
+        suspend_phys_cpu_id = __cpu_logical_map[suspend_lowcore->cpu_nr];
+        suspend_cpu_id = suspend_lowcore->cpu_nr;
+
+        for_each_present_cpu(cpu) {
+                if (__cpu_logical_map[cpu] == resume_phys_cpu_id) {
+                        resume_cpu_id = cpu;
+                        goto found;
+                }
+        }
+        panic("Could not find resume cpu in logical map.\n");
+
+found:
+        printk("Resume  cpu ID: %i/%i\n", resume_phys_cpu_id, resume_cpu_id);
+        printk("Suspend cpu ID: %i/%i\n", suspend_phys_cpu_id, suspend_cpu_id);
+
+        __cpu_logical_map[resume_cpu_id] = suspend_phys_cpu_id;
+        __cpu_logical_map[suspend_cpu_id] = resume_phys_cpu_id;
+
+        lowcore_ptr[suspend_cpu_id]->cpu_addr = resume_phys_cpu_id;
+}
+
+u32 smp_get_phys_cpu_id(void)
+{
+        return __cpu_logical_map[smp_processor_id()];
+}
+
 static int __init topology_init(void)
 {
         int cpu;
diff --git a/arch/s390/power/Makefile b/arch/s390/power/Makefile
new file mode 100644
index 000000000000..973bb45a8fec
--- /dev/null
+++ b/arch/s390/power/Makefile
@@ -0,0 +1,8 @@
+#
+# Makefile for s390 PM support
+#
+
+obj-$(CONFIG_HIBERNATION) += suspend.o
+obj-$(CONFIG_HIBERNATION) += swsusp.o
+obj-$(CONFIG_HIBERNATION) += swsusp_64.o
+obj-$(CONFIG_HIBERNATION) += swsusp_asm64.o
diff --git a/arch/s390/power/suspend.c b/arch/s390/power/suspend.c
new file mode 100644
index 000000000000..b3351eceebbe
--- /dev/null
+++ b/arch/s390/power/suspend.c
@@ -0,0 +1,40 @@
+/*
+ * Suspend support specific for s390.
+ *
+ * Copyright IBM Corp. 2009
+ *
+ * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/suspend.h>
+#include <linux/reboot.h>
+#include <linux/pfn.h>
+#include <asm/sections.h>
+#include <asm/ipl.h>
+
+/*
+ * References to section boundaries
+ */
+extern const void __nosave_begin, __nosave_end;
+
+/*
+ *  check if given pfn is in the 'nosave' or in the read only NSS section
+ */
+int pfn_is_nosave(unsigned long pfn)
+{
+        unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
+        unsigned long nosave_end_pfn = PAGE_ALIGN(__pa(&__nosave_end))
+                                        >> PAGE_SHIFT;
+        unsigned long eshared_pfn = PFN_DOWN(__pa(&_eshared)) - 1;
+        unsigned long stext_pfn = PFN_DOWN(__pa(&_stext));
+
+        if (pfn >= nosave_begin_pfn && pfn < nosave_end_pfn)
+                return 1;
+        if (pfn >= stext_pfn && pfn <= eshared_pfn) {
+                if (ipl_info.type == IPL_TYPE_NSS)
+                        return 1;
+        } else if ((tprot(pfn * PAGE_SIZE) && pfn > 0))
+                return 1;
+        return 0;
+}
diff --git a/arch/s390/power/swsusp.c b/arch/s390/power/swsusp.c
new file mode 100644
index 000000000000..e6a4fe9f5f24
--- /dev/null
+++ b/arch/s390/power/swsusp.c
@@ -0,0 +1,30 @@
+/*
+ * Support for suspend and resume on s390
+ *
+ * Copyright IBM Corp. 2009
+ *
+ * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
+ *
+ */
+
+
+/*
+ * save CPU registers before creating a hibernation image and before
+ * restoring the memory state from it
+ */
+void save_processor_state(void)
+{
+        /* implentation contained in the
+         * swsusp_arch_suspend function
+         */
+}
+
+/*
+ * restore the contents of CPU registers
+ */
+void restore_processor_state(void)
+{
+        /* implentation contained in the
+         * swsusp_arch_resume function
+         */
+}
diff --git a/arch/s390/power/swsusp_64.c b/arch/s390/power/swsusp_64.c
new file mode 100644
index 000000000000..9516a517d72f
--- /dev/null
+++ b/arch/s390/power/swsusp_64.c
@@ -0,0 +1,17 @@
+/*
+ * Support for suspend and resume on s390
+ *
+ * Copyright IBM Corp. 2009
+ *
+ * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
+ *
+ */
+
+#include <asm/system.h>
+#include <linux/interrupt.h>
+
+void do_after_copyback(void)
+{
+        mb();
+}
+
diff --git a/arch/s390/power/swsusp_asm64.S b/arch/s390/power/swsusp_asm64.S
new file mode 100644
index 000000000000..3c74e7d827c9
--- /dev/null
+++ b/arch/s390/power/swsusp_asm64.S
@@ -0,0 +1,199 @@
+/*
+ * S390 64-bit swsusp implementation
+ *
+ * Copyright IBM Corp. 2009
+ *
+ * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com>
+ *            Michael Holzheu <holzheu@linux.vnet.ibm.com>
+ */
+
+#include <asm/page.h>
+#include <asm/ptrace.h>
+#include <asm/asm-offsets.h>
+
+/*
+ * Save register context in absolute 0 lowcore and call swsusp_save() to
+ * create in-memory kernel image. The context is saved in the designated
+ * "store status" memory locations (see POP).
+ * We return from this function twice. The first time during the suspend to
+ * disk process. The second time via the swsusp_arch_resume() function
+ * (see below) in the resume process.
+ * This function runs with disabled interrupts.
+ */
+        .section .text
+        .align  2
+        .globl swsusp_arch_suspend
+swsusp_arch_suspend:
+        stmg    %r6,%r15,__SF_GPRS(%r15)
+        lgr     %r1,%r15
+        aghi    %r15,-STACK_FRAME_OVERHEAD
+        stg     %r1,__SF_BACKCHAIN(%r15)
+
+        /* Deactivate DAT */
+        stnsm   __SF_EMPTY(%r15),0xfb
+
+        /* Switch off lowcore protection */
+        stctg   %c0,%c0,__SF_EMPTY(%r15)
+        ni      __SF_EMPTY+4(%r15),0xef
+        lctlg   %c0,%c0,__SF_EMPTY(%r15)
+
+        /* Store prefix register on stack */
+        stpx    __SF_EMPTY(%r15)
+
+        /* Setup base register for lowcore (absolute 0) */
+        llgf    %r1,__SF_EMPTY(%r15)
+
+        /* Get pointer to save area */
+        aghi    %r1,0x1000
+
+        /* Store registers */
+        mvc     0x318(4,%r1),__SF_EMPTY(%r15)   /* move prefix to lowcore */
+        stfpc   0x31c(%r1)                      /* store fpu control */
+        std     0,0x200(%r1)                    /* store f0 */
+        std     1,0x208(%r1)                    /* store f1 */
+        std     2,0x210(%r1)                    /* store f2 */
+        std     3,0x218(%r1)                    /* store f3 */
+        std     4,0x220(%r1)                    /* store f4 */
+        std     5,0x228(%r1)                    /* store f5 */
+        std     6,0x230(%r1)                    /* store f6 */
+        std     7,0x238(%r1)                    /* store f7 */
+        std     8,0x240(%r1)                    /* store f8 */
+        std     9,0x248(%r1)                    /* store f9 */
+        std     10,0x250(%r1)                   /* store f10 */
+        std     11,0x258(%r1)                   /* store f11 */
+        std     12,0x260(%r1)                   /* store f12 */
+        std     13,0x268(%r1)                   /* store f13 */
+        std     14,0x270(%r1)                   /* store f14 */
+        std     15,0x278(%r1)                   /* store f15 */
+        stam    %a0,%a15,0x340(%r1)             /* store access registers */
+        stctg   %c0,%c15,0x380(%r1)             /* store control registers */
+        stmg    %r0,%r15,0x280(%r1)             /* store general registers */
+
+        stpt    0x328(%r1)                      /* store timer */
+        stckc   0x330(%r1)                      /* store clock comparator */
+
+        /* Activate DAT */
+        stosm   __SF_EMPTY(%r15),0x04
+
+        /* Set prefix page to zero */
+        xc      __SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
+        spx     __SF_EMPTY(%r15)
+
+        /* Setup lowcore */
+        brasl   %r14,setup_lowcore_early
+
+        /* Save image */
+        brasl   %r14,swsusp_save
+
+        /* Switch on lowcore protection */
+        stctg   %c0,%c0,__SF_EMPTY(%r15)
+        oi      __SF_EMPTY+4(%r15),0x10
+        lctlg   %c0,%c0,__SF_EMPTY(%r15)
+
+        /* Restore prefix register and return */
+        lghi    %r1,0x1000
+        spx     0x318(%r1)
+        lmg     %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
+        lghi    %r2,0
+        br      %r14
+
+/*
+ * Restore saved memory image to correct place and restore register context.
+ * Then we return to the function that called swsusp_arch_suspend().
+ * swsusp_arch_resume() runs with disabled interrupts.
+ */
+        .globl swsusp_arch_resume
+swsusp_arch_resume:
+        stmg    %r6,%r15,__SF_GPRS(%r15)
+        lgr     %r1,%r15
+        aghi    %r15,-STACK_FRAME_OVERHEAD
+        stg     %r1,__SF_BACKCHAIN(%r15)
+
+        /* Save boot cpu number */
+        brasl   %r14,smp_get_phys_cpu_id
+        lgr     %r10,%r2
+
+        /* Deactivate DAT */
+        stnsm   __SF_EMPTY(%r15),0xfb
+
+        /* Switch off lowcore protection */
+        stctg   %c0,%c0,__SF_EMPTY(%r15)
+        ni      __SF_EMPTY+4(%r15),0xef
+        lctlg   %c0,%c0,__SF_EMPTY(%r15)
+
+        /* Set prefix page to zero */
+        xc      __SF_EMPTY(4,%r15),__SF_EMPTY(%r15)
+        spx     __SF_EMPTY(%r15)
+
+        /* Restore saved image */
+        larl    %r1,restore_pblist
+        lg      %r1,0(%r1)
+        ltgr    %r1,%r1
+        jz      2f
+0:
+        lg      %r2,8(%r1)
+        lg      %r4,0(%r1)
+        lghi    %r3,PAGE_SIZE
+        lghi    %r5,PAGE_SIZE
+1:
+        mvcle   %r2,%r4,0
+        jo      1b
+        lg      %r1,16(%r1)
+        ltgr    %r1,%r1
+        jnz     0b
+2:
+        ptlb                            /* flush tlb */
+
+        /* Restore registers */
+        lghi    %r13,0x1000             /* %r1 = pointer to save arae */
+
+        spt     0x328(%r13)             /* reprogram timer */
+        //sckc  0x330(%r13)             /* set clock comparator */
+
+        lctlg   %c0,%c15,0x380(%r13)    /* load control registers */
+        lam     %a0,%a15,0x340(%r13)    /* load access registers */
+
+        lfpc    0x31c(%r13)             /* load fpu control */
+        ld      0,0x200(%r13)           /* load f0 */
+        ld      1,0x208(%r13)           /* load f1 */
+        ld      2,0x210(%r13)           /* load f2 */
+        ld      3,0x218(%r13)           /* load f3 */
+        ld      4,0x220(%r13)           /* load f4 */
+        ld      5,0x228(%r13)           /* load f5 */
+        ld      6,0x230(%r13)           /* load f6 */
+        ld      7,0x238(%r13)           /* load f7 */
+        ld      8,0x240(%r13)           /* load f8 */
+        ld      9,0x248(%r13)           /* load f9 */
+        ld      10,0x250(%r13)          /* load f10 */
+        ld      11,0x258(%r13)          /* load f11 */
+        ld      12,0x260(%r13)          /* load f12 */
+        ld      13,0x268(%r13)          /* load f13 */
+        ld      14,0x270(%r13)          /* load f14 */
+        ld      15,0x278(%r13)          /* load f15 */
+
+        /* Load old stack */
+        lg      %r15,0x2f8(%r13)
+
+        /* Pointer to save arae */
+        lghi    %r13,0x1000
+
+        /* Switch CPUs */
+        lgr     %r2,%r10                /* get cpu id */
+        llgf    %r3,0x318(%r13)
+        brasl   %r14,smp_switch_boot_cpu_in_resume
+
+        /* Restore prefix register */
+        spx     0x318(%r13)
+
+        /* Switch on lowcore protection */
+        stctg   %c0,%c0,__SF_EMPTY(%r15)
+        oi      __SF_EMPTY+4(%r15),0x10
+        lctlg   %c0,%c0,__SF_EMPTY(%r15)
+
+        /* Activate DAT */
+        stosm   __SF_EMPTY(%r15),0x04
+
+        /* Return 0 */
+        lmg     %r6,%r15,STACK_FRAME_OVERHEAD + __SF_GPRS(%r15)
+        lghi    %r2,0
+        br      %r14