[PATCH] lockdep: annotate on-stack completions
[powerpc.git] / drivers / s390 / s390mach.c
index 4191fd9..ffb3677 100644 (file)
@@ -8,11 +8,12 @@
  *              Martin Schwidefsky (schwidefsky@de.ibm.com)
  */
 
-#include <linux/config.h>
 #include <linux/init.h>
 #include <linux/sched.h>
 #include <linux/errno.h>
 #include <linux/workqueue.h>
+#include <linux/time.h>
+#include <linux/kthread.h>
 
 #include <asm/lowcore.h>
 
@@ -23,7 +24,7 @@
 
 static struct semaphore m_sem;
 
-extern int css_process_crw(int);
+extern int css_process_crw(int, int);
 extern int chsc_process_crw(void);
 extern int chp_process_crw(int, int);
 extern void css_reiterate_subchannels(void);
@@ -49,35 +50,59 @@ s390_handle_damage(char *msg)
 static int
 s390_collect_crw_info(void *param)
 {
-       struct crw crw;
+       struct crw crw[2];
        int ccode, ret, slow;
        struct semaphore *sem;
+       unsigned int chain;
 
        sem = (struct semaphore *)param;
-       /* Set a nice name. */
-       daemonize("kmcheck");
 repeat:
        down_interruptible(sem);
        slow = 0;
+       chain = 0;
        while (1) {
-               ccode = stcrw(&crw);
+               if (unlikely(chain > 1)) {
+                       struct crw tmp_crw;
+
+                       printk(KERN_WARNING"%s: Code does not support more "
+                              "than two chained crws; please report to "
+                              "linux390@de.ibm.com!\n", __FUNCTION__);
+                       ccode = stcrw(&tmp_crw);
+                       printk(KERN_WARNING"%s: crw reports slct=%d, oflw=%d, "
+                              "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
+                              __FUNCTION__, tmp_crw.slct, tmp_crw.oflw,
+                              tmp_crw.chn, tmp_crw.rsc, tmp_crw.anc,
+                              tmp_crw.erc, tmp_crw.rsid);
+                       printk(KERN_WARNING"%s: This was crw number %x in the "
+                              "chain\n", __FUNCTION__, chain);
+                       if (ccode != 0)
+                               break;
+                       chain = tmp_crw.chn ? chain + 1 : 0;
+                       continue;
+               }
+               ccode = stcrw(&crw[chain]);
                if (ccode != 0)
                        break;
                DBG(KERN_DEBUG "crw_info : CRW reports slct=%d, oflw=%d, "
                    "chn=%d, rsc=%X, anc=%d, erc=%X, rsid=%X\n",
-                   crw.slct, crw.oflw, crw.chn, crw.rsc, crw.anc,
-                   crw.erc, crw.rsid);
+                   crw[chain].slct, crw[chain].oflw, crw[chain].chn,
+                   crw[chain].rsc, crw[chain].anc, crw[chain].erc,
+                   crw[chain].rsid);
                /* Check for overflows. */
-               if (crw.oflw) {
+               if (crw[chain].oflw) {
                        pr_debug("%s: crw overflow detected!\n", __FUNCTION__);
                        css_reiterate_subchannels();
+                       chain = 0;
                        slow = 1;
                        continue;
                }
-               switch (crw.rsc) {
+               switch (crw[chain].rsc) {
                case CRW_RSC_SCH:
-                       pr_debug("source is subchannel %04X\n", crw.rsid);
-                       ret = css_process_crw (crw.rsid);
+                       if (crw[0].chn && !chain)
+                               break;
+                       pr_debug("source is subchannel %04X\n", crw[0].rsid);
+                       ret = css_process_crw (crw[0].rsid,
+                                              chain ? crw[1].rsid : 0);
                        if (ret == -EAGAIN)
                                slow = 1;
                        break;
@@ -85,18 +110,18 @@ repeat:
                        pr_debug("source is monitoring facility\n");
                        break;
                case CRW_RSC_CPATH:
-                       pr_debug("source is channel path %02X\n", crw.rsid);
-                       switch (crw.erc) {
+                       pr_debug("source is channel path %02X\n", crw[0].rsid);
+                       switch (crw[0].erc) {
                        case CRW_ERC_IPARM: /* Path has come. */
-                               ret = chp_process_crw(crw.rsid, 1);
+                               ret = chp_process_crw(crw[0].rsid, 1);
                                break;
                        case CRW_ERC_PERRI: /* Path has gone. */
                        case CRW_ERC_PERRN:
-                               ret = chp_process_crw(crw.rsid, 0);
+                               ret = chp_process_crw(crw[0].rsid, 0);
                                break;
                        default:
                                pr_debug("Don't know how to handle erc=%x\n",
-                                        crw.erc);
+                                        crw[0].erc);
                                ret = 0;
                        }
                        if (ret == -EAGAIN)
@@ -115,6 +140,8 @@ repeat:
                        pr_debug("unknown source\n");
                        break;
                }
+               /* chain is always 0 or 1 here. */
+               chain = crw[chain].chn ? chain + 1 : 0;
        }
        if (slow)
                queue_work(slow_path_wq, &slow_path_work);
@@ -218,7 +245,7 @@ s390_revalidate_registers(struct mci *mci)
                 */
                kill_task = 1;
 
-#ifndef __s390x__
+#ifndef CONFIG_64BIT
        asm volatile("ld 0,0(%0)\n"
                     "ld 2,8(%0)\n"
                     "ld 4,16(%0)\n"
@@ -227,7 +254,7 @@ s390_revalidate_registers(struct mci *mci)
 #endif
 
        if (MACHINE_HAS_IEEE) {
-#ifdef __s390x__
+#ifdef CONFIG_64BIT
                fpt_save_area = &S390_lowcore.floating_pt_save_area;
                fpt_creg_save_area = &S390_lowcore.fpt_creg_save_area;
 #else
@@ -286,7 +313,7 @@ s390_revalidate_registers(struct mci *mci)
                 */
                s390_handle_damage("invalid control registers.");
        else
-#ifdef __s390x__
+#ifdef CONFIG_64BIT
                asm volatile("lctlg 0,15,0(%0)"
                             : : "a" (&S390_lowcore.cregs_save_area));
 #else
@@ -299,7 +326,7 @@ s390_revalidate_registers(struct mci *mci)
         * can't write something sensible into that register.
         */
 
-#ifdef __s390x__
+#ifdef CONFIG_64BIT
        /*
         * See if we can revalidate the TOD programmable register with its
         * old contents (should be zero) otherwise set it to zero.
@@ -334,16 +361,25 @@ s390_revalidate_registers(struct mci *mci)
        return kill_task;
 }
 
+#define MAX_IPD_COUNT  29
+#define MAX_IPD_TIME   (5 * 60 * USEC_PER_SEC) /* 5 minutes */
+
 /*
  * machine check handler.
  */
 void
 s390_do_machine_check(struct pt_regs *regs)
 {
+       static DEFINE_SPINLOCK(ipd_lock);
+       static unsigned long long last_ipd;
+       static int ipd_count;
+       unsigned long long tmp;
        struct mci *mci;
        struct mcck_struct *mcck;
        int umode;
 
+       lockdep_off();
+
        mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
        mcck = &__get_cpu_var(cpu_mcck);
        umode = user_mode(regs);
@@ -356,7 +392,7 @@ s390_do_machine_check(struct pt_regs *regs)
                if (mci->b) {
                        /* Processing backup -> verify if we can survive this */
                        u64 z_mcic, o_mcic, t_mcic;
-#ifdef __s390x__
+#ifdef CONFIG_64BIT
                        z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
                        o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
                                  1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
@@ -376,11 +412,27 @@ s390_do_machine_check(struct pt_regs *regs)
                                s390_handle_damage("processing backup machine "
                                                   "check with damage.");
                        }
-                       if (!umode)
-                               s390_handle_damage("processing backup machine "
-                                                  "check in kernel mode.");
-                       mcck->kill_task = 1;
-                       mcck->mcck_code = *(unsigned long long *) mci;
+
+                       /*
+                        * Nullifying exigent condition, therefore we might
+                        * retry this instruction.
+                        */
+
+                       spin_lock(&ipd_lock);
+
+                       tmp = get_clock();
+
+                       if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
+                               ipd_count++;
+                       else
+                               ipd_count = 1;
+
+                       last_ipd = tmp;
+
+                       if (ipd_count == MAX_IPD_COUNT)
+                               s390_handle_damage("too many ipd retries.");
+
+                       spin_unlock(&ipd_lock);
                }
                else {
                        /* Processing damage -> stopping machine */
@@ -432,6 +484,7 @@ s390_do_machine_check(struct pt_regs *regs)
                mcck->warning = 1;
                set_thread_flag(TIF_MCCK_PENDING);
        }
+       lockdep_on();
 }
 
 /*
@@ -464,7 +517,7 @@ arch_initcall(machine_check_init);
 static int __init
 machine_check_crw_init (void)
 {
-       kernel_thread(s390_collect_crw_info, &m_sem, CLONE_FS|CLONE_FILES);
+       kthread_run(s390_collect_crw_info, &m_sem, "kmcheck");
        ctl_set_bit(14, 28);    /* enable channel report MCH */
        return 0;
 }