[S390] Reset infrastructure for re-IPL.
Heiko Carstens [Mon, 4 Dec 2006 14:40:26 +0000 (15:40 +0100)]
In case of re-IPL and diag308 doesn't work we have to reset all devices
manually and wait synchronously that each reset finished.
This patch adds the necessary infrastucture and the first exploiter of it.

Subsystems that need to add a function that needs to be called at re-IPL
may register/unregister this function via

struct reset_call {
struct reset_call *next;
void (*fn)(void);
};

void register_reset_call(struct reset_call *reset);
void unregister_reset_call(struct reset_call *reset);

When the registered function get called the context is:

- all cpus beside the current one are stopped
- all machine checks and interrupts are disabled
- prefixing is disabled
- a default machine check handler is available for use

The registered functions may not take any locks are sleep.

For the common I/O layer part of this patch:

Introduce a reset_call css_reset that does the following:
- clear all subchannels
- perform a rchp on all channel paths and wait for the resulting
  machine checks
This replaces the calls to clear_all_subchannels() and
cio_reset_channel_paths() for kexec and ccw reipl. reipl_ccw_dev() now
uses reipl_find_schid() to determine the subchannel id for a given
device id.
Also remove cio_reset_channel_paths() and friends since they are not
needed anymore.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

13 files changed:
arch/s390/kernel/Makefile
arch/s390/kernel/ipl.c
arch/s390/kernel/machine_kexec.c
arch/s390/kernel/reipl.S
arch/s390/kernel/reipl64.S
arch/s390/kernel/relocate_kernel.S
arch/s390/kernel/relocate_kernel64.S
arch/s390/kernel/reset.S [new file with mode: 0644]
drivers/s390/cio/chsc.c
drivers/s390/cio/cio.c
include/asm-s390/cio.h
include/asm-s390/lowcore.h
include/asm-s390/reset.h [new file with mode: 0644]

index aa97897..a81881c 100644 (file)
@@ -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
 
index ec12782..77f4aff 100644 (file)
@@ -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();
+}
index 60b1ea9..202bf1f 100644 (file)
@@ -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);
index 0340477..f9434d4 100644 (file)
                .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
index de74350..f18ef26 100644 (file)
 #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
index f9899ff..3b456b8 100644 (file)
@@ -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:
index 4fb4430..1f9ea20 100644 (file)
@@ -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
                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 (file)
index 0000000..be8688c
--- /dev/null
@@ -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 */
index 2d78f0f..9d92540 100644 (file)
@@ -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)
 {
index 8936e46..20aee27 100644 (file)
@@ -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));
 }
 
index 81287d8..cabd5bb 100644 (file)
@@ -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);
index 06583ed..74f7389 100644 (file)
@@ -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 (file)
index 0000000..9b439cf
--- /dev/null
@@ -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 */