13 files changed, 246 insertions, 108 deletions

diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index aa978978d3d..a81881c9b29 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -4,7 +4,7 @@
 
 EXTRA_AFLAGS    := -traditional
 
-obj-y   :=  bitmap.o traps.o time.o process.o \
+obj-y   :=  bitmap.o traps.o time.o process.o reset.o \
             setup.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o \
             semaphore.o s390_ext.o debug.o profile.o irq.o ipl.o
 
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
index ec127826f22..77f4aff630f 100644
--- a/arch/s390/kernel/ipl.c
+++ b/arch/s390/kernel/ipl.c
@@ -19,6 +19,7 @@
 #include <asm/cpcmd.h>
 #include <asm/cio.h>
 #include <asm/ebcdic.h>
+#include <asm/reset.h>
 
 #define IPL_PARM_BLOCK_VERSION 0
 #define LOADPARM_LEN 8
@@ -1024,3 +1025,56 @@ static int __init s390_ipl_init(void)
 }
 
 __initcall(s390_ipl_init);
+
+static LIST_HEAD(rcall);
+static DEFINE_MUTEX(rcall_mutex);
+
+void register_reset_call(struct reset_call *reset)
+{
+        mutex_lock(&rcall_mutex);
+        list_add(&reset->list, &rcall);
+        mutex_unlock(&rcall_mutex);
+}
+EXPORT_SYMBOL_GPL(register_reset_call);
+
+void unregister_reset_call(struct reset_call *reset)
+{
+        mutex_lock(&rcall_mutex);
+        list_del(&reset->list);
+        mutex_unlock(&rcall_mutex);
+}
+EXPORT_SYMBOL_GPL(unregister_reset_call);
+
+static void do_reset_calls(void)
+{
+        struct reset_call *reset;
+
+        list_for_each_entry(reset, &rcall, list)
+                reset->fn();
+}
+
+extern void reset_mcck_handler(void);
+
+void s390_reset_system(void)
+{
+        struct _lowcore *lc;
+
+        /* Disable all interrupts/machine checks */
+        __load_psw_mask(PSW_KERNEL_BITS & ~PSW_MASK_MCHECK);
+
+        /* Stack for interrupt/machine check handler */
+        lc = (struct _lowcore *)(unsigned long) store_prefix();
+        lc->panic_stack = S390_lowcore.panic_stack;
+
+        /* Disable prefixing */
+        set_prefix(0);
+
+        /* Disable lowcore protection */
+        __ctl_clear_bit(0,28);
+
+        /* Set new machine check handler */
+        S390_lowcore.mcck_new_psw.mask = PSW_KERNEL_BITS & ~PSW_MASK_MCHECK;
+        S390_lowcore.mcck_new_psw.addr =
+                PSW_ADDR_AMODE | (unsigned long) &reset_mcck_handler;
+        do_reset_calls();
+}
diff --git a/arch/s390/kernel/machine_kexec.c b/arch/s390/kernel/machine_kexec.c
index 60b1ea9f946..202bf1fdfe3 100644
--- a/arch/s390/kernel/machine_kexec.c
+++ b/arch/s390/kernel/machine_kexec.c
@@ -22,6 +22,7 @@
 #include <asm/pgalloc.h>
 #include <asm/system.h>
 #include <asm/smp.h>
+#include <asm/reset.h>
 
 static void kexec_halt_all_cpus(void *);
 
@@ -62,12 +63,6 @@ machine_shutdown(void)
 NORET_TYPE void
 machine_kexec(struct kimage *image)
 {
-        clear_all_subchannels();
-        cio_reset_channel_paths();
-
-        /* Disable lowcore protection */
-        ctl_clear_bit(0,28);
-
         on_each_cpu(kexec_halt_all_cpus, image, 0, 0);
         for (;;);
 }
@@ -98,6 +93,8 @@ kexec_halt_all_cpus(void *kernel_image)
                         cpu_relax();
         }
 
+        s390_reset_system();
+
         image = (struct kimage *) kernel_image;
         data_mover = (relocate_kernel_t)
                 (page_to_pfn(image->control_code_page) << PAGE_SHIFT);
diff --git a/arch/s390/kernel/reipl.S b/arch/s390/kernel/reipl.S
index 0340477f3b0..f9434d42ce9 100644
--- a/arch/s390/kernel/reipl.S
+++ b/arch/s390/kernel/reipl.S
@@ -11,19 +11,10 @@
                 .globl  do_reipl_asm
 do_reipl_asm:   basr    %r13,0
 .Lpg0:          lpsw    .Lnewpsw-.Lpg0(%r13)
-
-                # switch off lowcore protection
-
-.Lpg1:          stctl   %c0,%c0,.Lctlsave1-.Lpg0(%r13)
-                stctl   %c0,%c0,.Lctlsave2-.Lpg0(%r13)
-                ni      .Lctlsave1-.Lpg0(%r13),0xef
-                lctl    %c0,%c0,.Lctlsave1-.Lpg0(%r13)
-
-                # do store status of all registers
+.Lpg1:          # do store status of all registers
 
                 stm     %r0,%r15,__LC_GPREGS_SAVE_AREA
                 stctl   %c0,%c15,__LC_CREGS_SAVE_AREA
-                mvc     __LC_CREGS_SAVE_AREA(4),.Lctlsave2-.Lpg0(%r13)
                 stam    %a0,%a15,__LC_AREGS_SAVE_AREA
                 stpx    __LC_PREFIX_SAVE_AREA
                 stckc   .Lclkcmp-.Lpg0(%r13)
@@ -56,8 +47,7 @@ do_reipl_asm:	basr	%r13,0
 .L002:          tm      .Liplirb+8-.Lpg0(%r13),0xf3
                 jz      .L003
                 bas     %r14,.Ldisab-.Lpg0(%r13)
-.L003:          spx     .Lnull-.Lpg0(%r13)
-                st      %r1,__LC_SUBCHANNEL_ID
+.L003:          st      %r1,__LC_SUBCHANNEL_ID
                 lpsw    0
                 sigp    0,0,0(6)
 .Ldisab:        st      %r14,.Ldispsw+4-.Lpg0(%r13)
@@ -65,9 +55,6 @@ do_reipl_asm:	basr	%r13,0
                 .align  8
 .Lclkcmp:       .quad   0x0000000000000000
 .Lall:          .long   0xff000000
-.Lnull:         .long   0x00000000
-.Lctlsave1:     .long   0x00000000
-.Lctlsave2:     .long   0x00000000
                 .align  8
 .Lnewpsw:       .long   0x00080000,0x80000000+.Lpg1
 .Lpcnew:        .long   0x00080000,0x80000000+.Lecs
diff --git a/arch/s390/kernel/reipl64.S b/arch/s390/kernel/reipl64.S
index de7435054f7..f18ef260ca2 100644
--- a/arch/s390/kernel/reipl64.S
+++ b/arch/s390/kernel/reipl64.S
@@ -10,10 +10,10 @@
 #include <asm/lowcore.h>
                 .globl  do_reipl_asm
 do_reipl_asm:   basr    %r13,0
+.Lpg0:          lpswe   .Lnewpsw-.Lpg0(%r13)
+.Lpg1:          # do store status of all registers
 
-                # do store status of all registers
-
-.Lpg0:          stg     %r1,.Lregsave-.Lpg0(%r13)
+                stg     %r1,.Lregsave-.Lpg0(%r13)
                 lghi    %r1,0x1000
                 stmg    %r0,%r15,__LC_GPREGS_SAVE_AREA-0x1000(%r1)
                 lg      %r0,.Lregsave-.Lpg0(%r13)
@@ -27,11 +27,7 @@ do_reipl_asm:	basr	%r13,0
                 stpt    __LC_CPU_TIMER_SAVE_AREA-0x1000(%r1)
                 stg     %r13, __LC_PSW_SAVE_AREA-0x1000+8(%r1)
 
-                lpswe   .Lnewpsw-.Lpg0(%r13)
-.Lpg1:          lctlg   %c6,%c6,.Lall-.Lpg0(%r13)
-                stctg   %c0,%c0,.Lregsave-.Lpg0(%r13)
-                ni      .Lregsave+4-.Lpg0(%r13),0xef
-                lctlg   %c0,%c0,.Lregsave-.Lpg0(%r13)
+                lctlg   %c6,%c6,.Lall-.Lpg0(%r13)
                 lgr     %r1,%r2
                 mvc     __LC_PGM_NEW_PSW(16),.Lpcnew-.Lpg0(%r13)
                 stsch   .Lschib-.Lpg0(%r13)
@@ -56,8 +52,7 @@ do_reipl_asm:	basr	%r13,0
 .L002:          tm      .Liplirb+8-.Lpg0(%r13),0xf3
                 jz      .L003
                 bas     %r14,.Ldisab-.Lpg0(%r13)
-.L003:          spx     .Lnull-.Lpg0(%r13)
-                st      %r1,__LC_SUBCHANNEL_ID
+.L003:          st      %r1,__LC_SUBCHANNEL_ID
                 lhi     %r1,0            # mode 0 = esa
                 slr     %r0,%r0          # set cpuid to zero
                 sigp    %r1,%r0,0x12     # switch to esa mode
@@ -70,7 +65,6 @@ do_reipl_asm:	basr	%r13,0
 .Lclkcmp:       .quad   0x0000000000000000
 .Lall:          .quad   0x00000000ff000000
 .Lregsave:      .quad   0x0000000000000000
-.Lnull:         .long   0x0000000000000000
                 .align  16
 /*
  * These addresses have to be 31 bit otherwise
diff --git a/arch/s390/kernel/relocate_kernel.S b/arch/s390/kernel/relocate_kernel.S
index f9899ff2e5b..3b456b80bce 100644
--- a/arch/s390/kernel/relocate_kernel.S
+++ b/arch/s390/kernel/relocate_kernel.S
@@ -26,8 +26,7 @@
         relocate_kernel:
                 basr    %r13,0          # base address
         .base:
-                stnsm   sys_msk-.base(%r13),0xf8        # disable DAT and IRQ (external)
-                spx     zero64-.base(%r13)      # absolute addressing mode
+                stnsm   sys_msk-.base(%r13),0xfb        # disable DAT
                 stctl   %c0,%c15,ctlregs-.base(%r13)
                 stm     %r0,%r15,gprregs-.base(%r13)
                 la      %r1,load_psw-.base(%r13)
@@ -97,8 +96,6 @@
                 lpsw    0               # hopefully start new kernel...
 
                 .align  8
-        zero64:
-                .quad   0
         load_psw:
                 .long   0x00080000,0x80000000
         sys_msk:
diff --git a/arch/s390/kernel/relocate_kernel64.S b/arch/s390/kernel/relocate_kernel64.S
index 4fb443042d9..1f9ea2067b5 100644
--- a/arch/s390/kernel/relocate_kernel64.S
+++ b/arch/s390/kernel/relocate_kernel64.S
@@ -27,8 +27,7 @@
         relocate_kernel:
                 basr    %r13,0          # base address
         .base:
-                stnsm   sys_msk-.base(%r13),0xf8        # disable DAT and IRQs
-                spx     zero64-.base(%r13)      # absolute addressing mode
+                stnsm   sys_msk-.base(%r13),0xfb        # disable DAT
                 stctg   %c0,%c15,ctlregs-.base(%r13)
                 stmg    %r0,%r15,gprregs-.base(%r13)
                 lghi    %r0,3
@@ -100,8 +99,6 @@
                 lpsw    0               # hopefully start new kernel...
 
                 .align  8
-        zero64:
-                .quad   0
         load_psw:
                 .long   0x00080000,0x80000000
         sys_msk:
diff --git a/arch/s390/kernel/reset.S b/arch/s390/kernel/reset.S
new file mode 100644
index 00000000000..be8688c0665
--- /dev/null
+++ b/arch/s390/kernel/reset.S
@@ -0,0 +1,48 @@
+/*
+ *  arch/s390/kernel/reset.S
+ *
+ *    Copyright (C) IBM Corp. 2006
+ *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#include <asm/ptrace.h>
+#include <asm/lowcore.h>
+
+#ifdef CONFIG_64BIT
+
+        .globl  reset_mcck_handler
+reset_mcck_handler:
+        basr    %r13,0
+0:      lg      %r15,__LC_PANIC_STACK   # load panic stack
+        aghi    %r15,-STACK_FRAME_OVERHEAD
+        lg      %r1,s390_reset_mcck_handler-0b(%r13)
+        ltgr    %r1,%r1
+        jz      1f
+        basr    %r14,%r1
+1:      la      %r1,4095
+        lmg     %r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r1)
+        lpswe   __LC_MCK_OLD_PSW
+
+        .globl  s390_reset_mcck_handler
+s390_reset_mcck_handler:
+        .quad   0
+
+#else /* CONFIG_64BIT */
+
+        .globl  reset_mcck_handler
+reset_mcck_handler:
+        basr    %r13,0
+0:      l       %r15,__LC_PANIC_STACK   # load panic stack
+        ahi     %r15,-STACK_FRAME_OVERHEAD
+        l       %r1,s390_reset_mcck_handler-0b(%r13)
+        ltr     %r1,%r1
+        jz      1f
+        basr    %r14,%r1
+1:      lm      %r0,%r15,__LC_GPREGS_SAVE_AREA
+        lpsw    __LC_MCK_OLD_PSW
+
+        .globl  s390_reset_mcck_handler
+s390_reset_mcck_handler:
+        .long   0
+
+#endif /* CONFIG_64BIT */
diff --git a/drivers/s390/cio/chsc.c b/drivers/s390/cio/chsc.c
index 2d78f0f4a40..9d92540bd99 100644
--- a/drivers/s390/cio/chsc.c
+++ b/drivers/s390/cio/chsc.c
@@ -1465,41 +1465,6 @@ chsc_get_chp_desc(struct subchannel *sch, int chp_no)
         return desc;
 }
 
-static int reset_channel_path(struct channel_path *chp)
-{
-        int cc;
-
-        cc = rchp(chp->id);
-        switch (cc) {
-        case 0:
-                return 0;
-        case 2:
-                return -EBUSY;
-        default:
-                return -ENODEV;
-        }
-}
-
-static void reset_channel_paths_css(struct channel_subsystem *css)
-{
-        int i;
-
-        for (i = 0; i <= __MAX_CHPID; i++) {
-                if (css->chps[i])
-                        reset_channel_path(css->chps[i]);
-        }
-}
-
-void cio_reset_channel_paths(void)
-{
-        int i;
-
-        for (i = 0; i <= __MAX_CSSID; i++) {
-                if (css[i] && css[i]->valid)
-                        reset_channel_paths_css(css[i]);
-        }
-}
-
 static int __init
 chsc_alloc_sei_area(void)
 {
diff --git a/drivers/s390/cio/cio.c b/drivers/s390/cio/cio.c
index 8936e460a80..20aee278384 100644
--- a/drivers/s390/cio/cio.c
+++ b/drivers/s390/cio/cio.c
@@ -21,6 +21,7 @@
 #include <asm/irq.h>
 #include <asm/irq_regs.h>
 #include <asm/setup.h>
+#include <asm/reset.h>
 #include "airq.h"
 #include "cio.h"
 #include "css.h"
@@ -28,6 +29,7 @@
 #include "ioasm.h"
 #include "blacklist.h"
 #include "cio_debug.h"
+#include "../s390mach.h"
 
 debug_info_t *cio_debug_msg_id;
 debug_info_t *cio_debug_trace_id;
@@ -841,26 +843,12 @@ __clear_subchannel_easy(struct subchannel_id schid)
         return -EBUSY;
 }
 
-struct sch_match_id {
-        struct subchannel_id schid;
-        struct ccw_dev_id devid;
-        int rc;
-};
-
-static int __shutdown_subchannel_easy_and_match(struct subchannel_id schid,
-        void *data)
+static int __shutdown_subchannel_easy(struct subchannel_id schid, void *data)
 {
         struct schib schib;
-        struct sch_match_id *match_id = data;
 
         if (stsch_err(schid, &schib))
                 return -ENXIO;
-        if (match_id && schib.pmcw.dnv &&
-                (schib.pmcw.dev == match_id->devid.devno) &&
-                (schid.ssid == match_id->devid.ssid)) {
-                match_id->schid = schid;
-                match_id->rc = 0;
-        }
         if (!schib.pmcw.ena)
                 return 0;
         switch(__disable_subchannel_easy(schid, &schib)) {
@@ -876,27 +864,111 @@ static int __shutdown_subchannel_easy_and_match(struct subchannel_id schid,
         return 0;
 }
 
-static int clear_all_subchannels_and_match(struct ccw_dev_id *devid,
-        struct subchannel_id *schid)
+static atomic_t chpid_reset_count;
+
+static void s390_reset_chpids_mcck_handler(void)
+{
+        struct crw crw;
+        struct mci *mci;
+
+        /* Check for pending channel report word. */
+        mci = (struct mci *)&S390_lowcore.mcck_interruption_code;
+        if (!mci->cp)
+                return;
+        /* Process channel report words. */
+        while (stcrw(&crw) == 0) {
+                /* Check for responses to RCHP. */
+                if (crw.slct && crw.rsc == CRW_RSC_CPATH)
+                        atomic_dec(&chpid_reset_count);
+        }
+}
+
+#define RCHP_TIMEOUT (30 * USEC_PER_SEC)
+static void css_reset(void)
+{
+        int i, ret;
+        unsigned long long timeout;
+
+        /* Reset subchannels. */
+        for_each_subchannel(__shutdown_subchannel_easy,  NULL);
+        /* Reset channel paths. */
+        s390_reset_mcck_handler = s390_reset_chpids_mcck_handler;
+        /* Enable channel report machine checks. */
+        __ctl_set_bit(14, 28);
+        /* Temporarily reenable machine checks. */
+        local_mcck_enable();
+        for (i = 0; i <= __MAX_CHPID; i++) {
+                ret = rchp(i);
+                if ((ret == 0) || (ret == 2))
+                        /*
+                         * rchp either succeeded, or another rchp is already
+                         * in progress. In either case, we'll get a crw.
+                         */
+                        atomic_inc(&chpid_reset_count);
+        }
+        /* Wait for machine check for all channel paths. */
+        timeout = get_clock() + (RCHP_TIMEOUT << 12);
+        while (atomic_read(&chpid_reset_count) != 0) {
+                if (get_clock() > timeout)
+                        break;
+                cpu_relax();
+        }
+        /* Disable machine checks again. */
+        local_mcck_disable();
+        /* Disable channel report machine checks. */
+        __ctl_clear_bit(14, 28);
+        s390_reset_mcck_handler = NULL;
+}
+
+static struct reset_call css_reset_call = {
+        .fn = css_reset,
+};
+
+static int __init init_css_reset_call(void)
+{
+        atomic_set(&chpid_reset_count, 0);
+        register_reset_call(&css_reset_call);
+        return 0;
+}
+
+arch_initcall(init_css_reset_call);
+
+struct sch_match_id {
+        struct subchannel_id schid;
+        struct ccw_dev_id devid;
+        int rc;
+};
+
+static int __reipl_subchannel_match(struct subchannel_id schid, void *data)
+{
+        struct schib schib;
+        struct sch_match_id *match_id = data;
+
+        if (stsch_err(schid, &schib))
+                return -ENXIO;
+        if (schib.pmcw.dnv &&
+            (schib.pmcw.dev == match_id->devid.devno) &&
+            (schid.ssid == match_id->devid.ssid)) {
+                match_id->schid = schid;
+                match_id->rc = 0;
+                return 1;
+        }
+        return 0;
+}
+
+static int reipl_find_schid(struct ccw_dev_id *devid,
+                            struct subchannel_id *schid)
 {
         struct sch_match_id match_id;
 
         match_id.devid = *devid;
         match_id.rc = -ENODEV;
-        local_irq_disable();
-        for_each_subchannel(__shutdown_subchannel_easy_and_match, &match_id);
+        for_each_subchannel(__reipl_subchannel_match, &match_id);
         if (match_id.rc == 0)
                 *schid = match_id.schid;
         return match_id.rc;
 }
 
-
-void clear_all_subchannels(void)
-{
-        local_irq_disable();
-        for_each_subchannel(__shutdown_subchannel_easy_and_match, NULL);
-}
-
 extern void do_reipl_asm(__u32 schid);
 
 /* Make sure all subchannels are quiet before we re-ipl an lpar. */
@@ -904,9 +976,9 @@ void reipl_ccw_dev(struct ccw_dev_id *devid)
 {
         struct subchannel_id schid;
 
-        if (clear_all_subchannels_and_match(devid, &schid))
+        s390_reset_system();
+        if (reipl_find_schid(devid, &schid) != 0)
                 panic("IPL Device not found\n");
-        cio_reset_channel_paths();
         do_reipl_asm(*((__u32*)&schid));
 }
 
diff --git a/include/asm-s390/cio.h b/include/asm-s390/cio.h
index 81287d86329..cabd5bb74b5 100644
--- a/include/asm-s390/cio.h
+++ b/include/asm-s390/cio.h
@@ -285,10 +285,6 @@ extern int diag210(struct diag210 *addr);
 
 extern void wait_cons_dev(void);
 
-extern void clear_all_subchannels(void);
-
-extern void cio_reset_channel_paths(void);
-
 extern void css_schedule_reprobe(void);
 
 extern void reipl_ccw_dev(struct ccw_dev_id *id);
diff --git a/include/asm-s390/lowcore.h b/include/asm-s390/lowcore.h
index 06583ed0bde..74f7389bd3e 100644
--- a/include/asm-s390/lowcore.h
+++ b/include/asm-s390/lowcore.h
@@ -362,6 +362,14 @@ static inline void set_prefix(__u32 address)
         asm volatile("spx %0" : : "m" (address) : "memory");
 }
 
+static inline __u32 store_prefix(void)
+{
+        __u32 address;
+
+        asm volatile("stpx %0" : "=m" (address));
+        return address;
+}
+
 #define __PANIC_MAGIC           0xDEADC0DE
 
 #endif
diff --git a/include/asm-s390/reset.h b/include/asm-s390/reset.h
new file mode 100644
index 00000000000..9b439cf6780
--- /dev/null
+++ b/include/asm-s390/reset.h
@@ -0,0 +1,23 @@
+/*
+ *  include/asm-s390/reset.h
+ *
+ *    Copyright IBM Corp. 2006
+ *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
+ */
+
+#ifndef _ASM_S390_RESET_H
+#define _ASM_S390_RESET_H
+
+#include <linux/list.h>
+
+struct reset_call {
+        struct list_head list;
+        void (*fn)(void);
+};
+
+extern void register_reset_call(struct reset_call *reset);
+extern void unregister_reset_call(struct reset_call *reset);
+extern void s390_reset_system(void);
+extern void (*s390_reset_mcck_handler)(void);
+
+#endif /* _ASM_S390_RESET_H */