ASoC: Use card field to indicate whether a component is bound
[linux-2.6-block.git] / arch / s390 / kernel / nmi.c
1 /*
2  *   Machine check handler
3  *
4  *    Copyright IBM Corp. 2000, 2009
5  *    Author(s): Ingo Adlung <adlung@de.ibm.com>,
6  *               Martin Schwidefsky <schwidefsky@de.ibm.com>,
7  *               Cornelia Huck <cornelia.huck@de.ibm.com>,
8  *               Heiko Carstens <heiko.carstens@de.ibm.com>,
9  */
10
11 #include <linux/kernel_stat.h>
12 #include <linux/init.h>
13 #include <linux/errno.h>
14 #include <linux/hardirq.h>
15 #include <linux/time.h>
16 #include <linux/module.h>
17 #include <asm/lowcore.h>
18 #include <asm/smp.h>
19 #include <asm/etr.h>
20 #include <asm/cputime.h>
21 #include <asm/nmi.h>
22 #include <asm/crw.h>
23 #include <asm/switch_to.h>
24
25 struct mcck_struct {
26         int kill_task;
27         int channel_report;
28         int warning;
29         unsigned long long mcck_code;
30 };
31
32 static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
33
34 static void s390_handle_damage(char *msg)
35 {
36         smp_send_stop();
37         disabled_wait((unsigned long) __builtin_return_address(0));
38         while (1);
39 }
40
41 /*
42  * Main machine check handler function. Will be called with interrupts enabled
43  * or disabled and machine checks enabled or disabled.
44  */
45 void s390_handle_mcck(void)
46 {
47         unsigned long flags;
48         struct mcck_struct mcck;
49
50         /*
51          * Disable machine checks and get the current state of accumulated
52          * machine checks. Afterwards delete the old state and enable machine
53          * checks again.
54          */
55         local_irq_save(flags);
56         local_mcck_disable();
57         mcck = *this_cpu_ptr(&cpu_mcck);
58         memset(this_cpu_ptr(&cpu_mcck), 0, sizeof(mcck));
59         clear_cpu_flag(CIF_MCCK_PENDING);
60         local_mcck_enable();
61         local_irq_restore(flags);
62
63         if (mcck.channel_report)
64                 crw_handle_channel_report();
65         /*
66          * A warning may remain for a prolonged period on the bare iron.
67          * (actually until the machine is powered off, or the problem is gone)
68          * So we just stop listening for the WARNING MCH and avoid continuously
69          * being interrupted.  One caveat is however, that we must do this per
70          * processor and cannot use the smp version of ctl_clear_bit().
71          * On VM we only get one interrupt per virtally presented machinecheck.
72          * Though one suffices, we may get one interrupt per (virtual) cpu.
73          */
74         if (mcck.warning) {     /* WARNING pending ? */
75                 static int mchchk_wng_posted = 0;
76
77                 /* Use single cpu clear, as we cannot handle smp here. */
78                 __ctl_clear_bit(14, 24);        /* Disable WARNING MCH */
79                 if (xchg(&mchchk_wng_posted, 1) == 0)
80                         kill_cad_pid(SIGPWR, 1);
81         }
82         if (mcck.kill_task) {
83                 local_irq_enable();
84                 printk(KERN_EMERG "mcck: Terminating task because of machine "
85                        "malfunction (code 0x%016llx).\n", mcck.mcck_code);
86                 printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
87                        current->comm, current->pid);
88                 do_exit(SIGSEGV);
89         }
90 }
91 EXPORT_SYMBOL_GPL(s390_handle_mcck);
92
93 /*
94  * returns 0 if all registers could be validated
95  * returns 1 otherwise
96  */
97 static int notrace s390_revalidate_registers(struct mci *mci)
98 {
99         int kill_task;
100         u64 zero;
101         void *fpt_save_area, *fpt_creg_save_area;
102
103         kill_task = 0;
104         zero = 0;
105
106         if (!mci->gr) {
107                 /*
108                  * General purpose registers couldn't be restored and have
109                  * unknown contents. Process needs to be terminated.
110                  */
111                 kill_task = 1;
112         }
113         if (!mci->fp) {
114                 /*
115                  * Floating point registers can't be restored and
116                  * therefore the process needs to be terminated.
117                  */
118                 kill_task = 1;
119         }
120         fpt_save_area = &S390_lowcore.floating_pt_save_area;
121         fpt_creg_save_area = &S390_lowcore.fpt_creg_save_area;
122         if (!mci->fc) {
123                 /*
124                  * Floating point control register can't be restored.
125                  * Task will be terminated.
126                  */
127                 asm volatile("lfpc 0(%0)" : : "a" (&zero), "m" (zero));
128                 kill_task = 1;
129         } else
130                 asm volatile("lfpc 0(%0)" : : "a" (fpt_creg_save_area));
131
132         asm volatile(
133                 "       ld      0,0(%0)\n"
134                 "       ld      1,8(%0)\n"
135                 "       ld      2,16(%0)\n"
136                 "       ld      3,24(%0)\n"
137                 "       ld      4,32(%0)\n"
138                 "       ld      5,40(%0)\n"
139                 "       ld      6,48(%0)\n"
140                 "       ld      7,56(%0)\n"
141                 "       ld      8,64(%0)\n"
142                 "       ld      9,72(%0)\n"
143                 "       ld      10,80(%0)\n"
144                 "       ld      11,88(%0)\n"
145                 "       ld      12,96(%0)\n"
146                 "       ld      13,104(%0)\n"
147                 "       ld      14,112(%0)\n"
148                 "       ld      15,120(%0)\n"
149                 : : "a" (fpt_save_area));
150         /* Revalidate vector registers */
151         if (MACHINE_HAS_VX && current->thread.vxrs) {
152                 if (!mci->vr) {
153                         /*
154                          * Vector registers can't be restored and therefore
155                          * the process needs to be terminated.
156                          */
157                         kill_task = 1;
158                 }
159                 restore_vx_regs((__vector128 *)
160                                 S390_lowcore.vector_save_area_addr);
161         }
162         /* Revalidate access registers */
163         asm volatile(
164                 "       lam     0,15,0(%0)"
165                 : : "a" (&S390_lowcore.access_regs_save_area));
166         if (!mci->ar) {
167                 /*
168                  * Access registers have unknown contents.
169                  * Terminating task.
170                  */
171                 kill_task = 1;
172         }
173         /* Revalidate control registers */
174         if (!mci->cr) {
175                 /*
176                  * Control registers have unknown contents.
177                  * Can't recover and therefore stopping machine.
178                  */
179                 s390_handle_damage("invalid control registers.");
180         } else {
181                 asm volatile(
182                         "       lctlg   0,15,0(%0)"
183                         : : "a" (&S390_lowcore.cregs_save_area));
184         }
185         /*
186          * We don't even try to revalidate the TOD register, since we simply
187          * can't write something sensible into that register.
188          */
189         /*
190          * See if we can revalidate the TOD programmable register with its
191          * old contents (should be zero) otherwise set it to zero.
192          */
193         if (!mci->pr)
194                 asm volatile(
195                         "       sr      0,0\n"
196                         "       sckpf"
197                         : : : "0", "cc");
198         else
199                 asm volatile(
200                         "       l       0,0(%0)\n"
201                         "       sckpf"
202                         : : "a" (&S390_lowcore.tod_progreg_save_area)
203                         : "0", "cc");
204         /* Revalidate clock comparator register */
205         set_clock_comparator(S390_lowcore.clock_comparator);
206         /* Check if old PSW is valid */
207         if (!mci->wp)
208                 /*
209                  * Can't tell if we come from user or kernel mode
210                  * -> stopping machine.
211                  */
212                 s390_handle_damage("old psw invalid.");
213
214         if (!mci->ms || !mci->pm || !mci->ia)
215                 kill_task = 1;
216
217         return kill_task;
218 }
219
220 #define MAX_IPD_COUNT   29
221 #define MAX_IPD_TIME    (5 * 60 * USEC_PER_SEC) /* 5 minutes */
222
223 #define ED_STP_ISLAND   6       /* External damage STP island check */
224 #define ED_STP_SYNC     7       /* External damage STP sync check */
225 #define ED_ETR_SYNC     12      /* External damage ETR sync check */
226 #define ED_ETR_SWITCH   13      /* External damage ETR switch to local */
227
228 /*
229  * machine check handler.
230  */
231 void notrace s390_do_machine_check(struct pt_regs *regs)
232 {
233         static int ipd_count;
234         static DEFINE_SPINLOCK(ipd_lock);
235         static unsigned long long last_ipd;
236         struct mcck_struct *mcck;
237         unsigned long long tmp;
238         struct mci *mci;
239         int umode;
240
241         nmi_enter();
242         inc_irq_stat(NMI_NMI);
243         mci = (struct mci *) &S390_lowcore.mcck_interruption_code;
244         mcck = this_cpu_ptr(&cpu_mcck);
245         umode = user_mode(regs);
246
247         if (mci->sd) {
248                 /* System damage -> stopping machine */
249                 s390_handle_damage("received system damage machine check.");
250         }
251         if (mci->pd) {
252                 if (mci->b) {
253                         /* Processing backup -> verify if we can survive this */
254                         u64 z_mcic, o_mcic, t_mcic;
255                         z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
256                         o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
257                                   1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
258                                   1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
259                                   1ULL<<16);
260                         t_mcic = *(u64 *)mci;
261
262                         if (((t_mcic & z_mcic) != 0) ||
263                             ((t_mcic & o_mcic) != o_mcic)) {
264                                 s390_handle_damage("processing backup machine "
265                                                    "check with damage.");
266                         }
267
268                         /*
269                          * Nullifying exigent condition, therefore we might
270                          * retry this instruction.
271                          */
272                         spin_lock(&ipd_lock);
273                         tmp = get_tod_clock();
274                         if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
275                                 ipd_count++;
276                         else
277                                 ipd_count = 1;
278                         last_ipd = tmp;
279                         if (ipd_count == MAX_IPD_COUNT)
280                                 s390_handle_damage("too many ipd retries.");
281                         spin_unlock(&ipd_lock);
282                 } else {
283                         /* Processing damage -> stopping machine */
284                         s390_handle_damage("received instruction processing "
285                                            "damage machine check.");
286                 }
287         }
288         if (s390_revalidate_registers(mci)) {
289                 if (umode) {
290                         /*
291                          * Couldn't restore all register contents while in
292                          * user mode -> mark task for termination.
293                          */
294                         mcck->kill_task = 1;
295                         mcck->mcck_code = *(unsigned long long *) mci;
296                         set_cpu_flag(CIF_MCCK_PENDING);
297                 } else {
298                         /*
299                          * Couldn't restore all register contents while in
300                          * kernel mode -> stopping machine.
301                          */
302                         s390_handle_damage("unable to revalidate registers.");
303                 }
304         }
305         if (mci->cd) {
306                 /* Timing facility damage */
307                 s390_handle_damage("TOD clock damaged");
308         }
309         if (mci->ed && mci->ec) {
310                 /* External damage */
311                 if (S390_lowcore.external_damage_code & (1U << ED_ETR_SYNC))
312                         etr_sync_check();
313                 if (S390_lowcore.external_damage_code & (1U << ED_ETR_SWITCH))
314                         etr_switch_to_local();
315                 if (S390_lowcore.external_damage_code & (1U << ED_STP_SYNC))
316                         stp_sync_check();
317                 if (S390_lowcore.external_damage_code & (1U << ED_STP_ISLAND))
318                         stp_island_check();
319         }
320         if (mci->se)
321                 /* Storage error uncorrected */
322                 s390_handle_damage("received storage error uncorrected "
323                                    "machine check.");
324         if (mci->ke)
325                 /* Storage key-error uncorrected */
326                 s390_handle_damage("received storage key-error uncorrected "
327                                    "machine check.");
328         if (mci->ds && mci->fa)
329                 /* Storage degradation */
330                 s390_handle_damage("received storage degradation machine "
331                                    "check.");
332         if (mci->cp) {
333                 /* Channel report word pending */
334                 mcck->channel_report = 1;
335                 set_cpu_flag(CIF_MCCK_PENDING);
336         }
337         if (mci->w) {
338                 /* Warning pending */
339                 mcck->warning = 1;
340                 set_cpu_flag(CIF_MCCK_PENDING);
341         }
342         nmi_exit();
343 }
344
345 static int __init machine_check_init(void)
346 {
347         ctl_set_bit(14, 25);    /* enable external damage MCH */
348         ctl_set_bit(14, 27);    /* enable system recovery MCH */
349         ctl_set_bit(14, 24);    /* enable warning MCH */
350         return 0;
351 }
352 arch_initcall(machine_check_init);