Watchdog code tested only on josmp

f905c075 · Silas Boyd-Wickizer · 4c05b764 · f905c075 · f905c075 · f905c075
--- a/include/kernel.hh
+++ b/include/kernel.hh
@@ -62,6 +62,7 @@ u64             nsectime(void);

 // console.c
 void            cprintf(const char*, ...) __attribute__((format(printf, 1, 2)));
+void            __cprintf(const char *fmt, ...) __attribute__((format(printf, 1, 2)));
 void            vcprintf(const char *fmt, va_list ap);
 void            panic(const char*, ...) 
                  __noret__ __attribute__((format(printf, 1, 2)));
@@ -187,6 +188,7 @@ int             sampintr(struct trapframe*);
 void            sampdump(void);
 void            sampconf(void);
 void            sampidle(bool);
+void            wdpoke(void);

 // sched.cc
 void            addrun(struct proc *);

--- a/kernel/console.cc
+++ b/kernel/console.cc
@@ -96,7 +96,7 @@ snprintf(char *buf, u32 n, const char *fmt, ...)
  va_end(ap);
 }

-static void
+void
 __cprintf(const char *fmt, ...)
 {
  va_list ap;
@@ -156,7 +156,7 @@ printtrace(u64 rbp)

  getcallerpcs((void*)rbp, pc, NELEM(pc));
  for (int i = 0; i < NELEM(pc) && pc[i] != 0; i++)
-    __cprintf("  %p\n", pc[i]);
+    __cprintf("  %016lx\n", pc[i]);
 }

 void __noret__
@@ -175,8 +175,8 @@ kerneltrap(struct trapframe *tf)
    pid = myproc()->pid;
    kstack = myproc()->kstack;
  }
-  __cprintf("kernel trap %u cpu %u\n"
-          "  tf: rip %p rsp %p rbp %p cr2 %p cs %p\n"
+  __cprintf("kernel trap %lu cpu %u\n"
+          "  tf: rip %016lx rsp %016lx rbp %016lx cr2 %016lx cs %x\n"
          "  proc: name %s pid %u kstack %p\n",
          tf->trapno, mycpu()->id, 
          tf->rip, tf->rsp, tf->rbp, rcr2(), tf->cs,

--- a/kernel/sampler.cc
+++ b/kernel/sampler.cc
@@ -12,6 +12,7 @@
 #include "sampler.h"
 #include "major.h"
 #include "apic.hh"
+#include "percpu.hh"

 #define LOGHEADER_SZ (sizeof(struct logheader) + \
                      sizeof(((struct logheader*)0)->cpu[0])*NCPU)
@@ -19,6 +20,25 @@
 static volatile u64 selector;
 static volatile u64 period;

+static const u64 wd_period = 24000000000ul;
+#if defined(HW_josmp)
+static const u64 wd_selector =
+    0UL << 32 |
+    1 << 24 | 
+    1 << 22 | 
+    1 << 20 |
+    1 << 17 | 
+    1 << 16 | 
+    0x00 << 8 | 
+    0x76;
+#else
+static const u64 wd_selector = 0;
+#endif
+static percpu<bool> wd_flag;
+
+
+// XXX(sbw) max period should be (1 << (cntval_bits - 1)) - 1
+// XXX(sbw) should mask out higher order bits from period (e.g. the top 16 on amd)
 struct pmu {
  void (*config)(u64 ctr, u64 sel, u64 val);  
  u64 cntval_bits;
@@ -114,9 +134,33 @@ samplog(struct trapframe *tf)
  return 1;
 }

+static void
+wdcheck(struct trapframe* tf)
+{
+  if (! *wd_flag) {
+    // uartputc guarantees some output
+    uartputc('W');
+    uartputc('D');
+    uartputc('\n');
+    __cprintf("cpu%u: wdcheck\n", myid());
+    __cprintf("  %016lx\n", tf->rip);
+    printtrace(tf->rbp);
+  }
+  *wd_flag = false;
+}
+
+void
+wdpoke(void)
+{
+  *wd_flag = true;
+}
+
 int
 sampintr(struct trapframe *tf)
 {
+  int r = 0;
+  u64 cnt;
+
  // Acquire locks that we only acquire during NMI.
  // NMIs are disabled until the next iret.

@@ -124,14 +168,22 @@ sampintr(struct trapframe *tf)
  lapicpc(0);
  // Only level-triggered interrupts require an lapiceoi.

-  u64 cnt = rdpmc(0);
-  if (cnt & (1ULL << (pmu.cntval_bits - 1)))
-    return 0;
+  cnt = rdpmc(0);
+  if ((cnt & (1ULL << (pmu.cntval_bits - 1))) == 0) {
+    // We've overflowed
+    r = 1;
+    if (samplog(tf))
+      pmu.config(0, selector, -period);
+  }

-  if (samplog(tf))
-    pmu.config(0, selector, -period);
+  cnt = rdpmc(1);
+  if ((cnt & (1ULL << (pmu.cntval_bits - 1))) == 0) {
+    r = 1;
+    wdcheck(tf);
+    pmu.config(1, wd_selector, -wd_period);
+  }

-  return 1;
+  return r;
 }

 static int
@@ -247,6 +299,17 @@ sampwrite(struct inode *ip, const char *buf, u32 off, u32 n)
 }

 void
+initwd(void)
+{
+  wdpoke();
+  pushcli();
+#if defined(HW_josmp)
+  pmu.config(1, wd_selector, -wd_period);
+#endif  
+  popcli();
+}
+
+void
 initsamp(void)
 {
  if (myid() == mpbcpu()) {