[PATCH] powerpc: Fix kdump copy regs and dynamic allocate per-cpu crash notes
- This contains the arch specific changes for the following the
kdump generic fixes which were already accepted in the upstream.
. Capturing CPU registers (for the case of 'panic' and invoking
the dump using 'sysrq-trigger') from a function (stack frame) which will
be not be available during the kdump boot. Hence, might result in
invalid stack trace.
. Dynamically allocating per cpu ELF notes section instead of
statically for NR_CPUS.
- Fix the compiler warning in prom_init.c.
Signed-off-by: Haren Myneni <haren@us.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/crash.c b/arch/powerpc/kernel/crash.c
index 5f248e3..8c21d37 100644
--- a/arch/powerpc/kernel/crash.c
+++ b/arch/powerpc/kernel/crash.c
@@ -84,7 +84,10 @@
* squirrelled away. ELF notes happen to provide
* all of that that no need to invent something new.
*/
- buf = &crash_notes[cpu][0];
+ buf = (u32*)per_cpu_ptr(crash_notes, cpu);
+ if (!buf)
+ return;
+
memset(&prstatus, 0, sizeof(prstatus));
prstatus.pr_pid = current->pid;
elf_core_copy_regs(&prstatus.pr_reg, regs);
@@ -93,76 +96,6 @@
final_note(buf);
}
-/* FIXME Merge this with xmon_save_regs ?? */
-static inline void crash_get_current_regs(struct pt_regs *regs)
-{
- unsigned long tmp1, tmp2;
-
- __asm__ __volatile__ (
- "std 0,0(%2)\n"
- "std 1,8(%2)\n"
- "std 2,16(%2)\n"
- "std 3,24(%2)\n"
- "std 4,32(%2)\n"
- "std 5,40(%2)\n"
- "std 6,48(%2)\n"
- "std 7,56(%2)\n"
- "std 8,64(%2)\n"
- "std 9,72(%2)\n"
- "std 10,80(%2)\n"
- "std 11,88(%2)\n"
- "std 12,96(%2)\n"
- "std 13,104(%2)\n"
- "std 14,112(%2)\n"
- "std 15,120(%2)\n"
- "std 16,128(%2)\n"
- "std 17,136(%2)\n"
- "std 18,144(%2)\n"
- "std 19,152(%2)\n"
- "std 20,160(%2)\n"
- "std 21,168(%2)\n"
- "std 22,176(%2)\n"
- "std 23,184(%2)\n"
- "std 24,192(%2)\n"
- "std 25,200(%2)\n"
- "std 26,208(%2)\n"
- "std 27,216(%2)\n"
- "std 28,224(%2)\n"
- "std 29,232(%2)\n"
- "std 30,240(%2)\n"
- "std 31,248(%2)\n"
- "mfmsr %0\n"
- "std %0, 264(%2)\n"
- "mfctr %0\n"
- "std %0, 280(%2)\n"
- "mflr %0\n"
- "std %0, 288(%2)\n"
- "bl 1f\n"
- "1: mflr %1\n"
- "std %1, 256(%2)\n"
- "mtlr %0\n"
- "mfxer %0\n"
- "std %0, 296(%2)\n"
- : "=&r" (tmp1), "=&r" (tmp2)
- : "b" (regs));
-}
-
-/* We may have saved_regs from where the error came from
- * or it is NULL if via a direct panic().
- */
-static void crash_save_self(struct pt_regs *saved_regs)
-{
- struct pt_regs regs;
- int cpu;
-
- cpu = smp_processor_id();
- if (saved_regs)
- memcpy(®s, saved_regs, sizeof(regs));
- else
- crash_get_current_regs(®s);
- crash_save_this_cpu(®s, cpu);
-}
-
#ifdef CONFIG_SMP
static atomic_t waiting_for_crash_ipi;
@@ -260,5 +193,5 @@
*/
crashing_cpu = smp_processor_id();
crash_kexec_prepare_cpus();
- crash_save_self(regs);
+ crash_save_this_cpu(regs, crashing_cpu);
}
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index d963a12..7881ec9 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -605,7 +605,8 @@
opt = strstr(RELOC(prom_cmd_line), RELOC("crashkernel="));
if (opt) {
opt += 12;
- RELOC(prom_crashk_size) = prom_memparse(opt, &opt);
+ RELOC(prom_crashk_size) =
+ prom_memparse(opt, (const char **)&opt);
if (ALIGN(RELOC(prom_crashk_size), 0x1000000) !=
RELOC(prom_crashk_size)) {
diff --git a/include/asm-powerpc/kexec.h b/include/asm-powerpc/kexec.h
index fffdf69..640a645 100644
--- a/include/asm-powerpc/kexec.h
+++ b/include/asm-powerpc/kexec.h
@@ -31,12 +31,80 @@
#define KEXEC_ARCH KEXEC_ARCH_PPC
#endif
-#define HAVE_ARCH_COPY_OLDMEM_PAGE
-
-#ifndef __ASSEMBLY__
-
#ifdef CONFIG_KEXEC
+#ifdef __powerpc64__
+/*
+ * This function is responsible for capturing register states if coming
+ * via panic or invoking dump using sysrq-trigger.
+ */
+static inline void crash_setup_regs(struct pt_regs *newregs,
+ struct pt_regs *oldregs)
+{
+ if (oldregs)
+ memcpy(newregs, oldregs, sizeof(*newregs));
+ else {
+ /* FIXME Merge this with xmon_save_regs ?? */
+ unsigned long tmp1, tmp2;
+ __asm__ __volatile__ (
+ "std 0,0(%2)\n"
+ "std 1,8(%2)\n"
+ "std 2,16(%2)\n"
+ "std 3,24(%2)\n"
+ "std 4,32(%2)\n"
+ "std 5,40(%2)\n"
+ "std 6,48(%2)\n"
+ "std 7,56(%2)\n"
+ "std 8,64(%2)\n"
+ "std 9,72(%2)\n"
+ "std 10,80(%2)\n"
+ "std 11,88(%2)\n"
+ "std 12,96(%2)\n"
+ "std 13,104(%2)\n"
+ "std 14,112(%2)\n"
+ "std 15,120(%2)\n"
+ "std 16,128(%2)\n"
+ "std 17,136(%2)\n"
+ "std 18,144(%2)\n"
+ "std 19,152(%2)\n"
+ "std 20,160(%2)\n"
+ "std 21,168(%2)\n"
+ "std 22,176(%2)\n"
+ "std 23,184(%2)\n"
+ "std 24,192(%2)\n"
+ "std 25,200(%2)\n"
+ "std 26,208(%2)\n"
+ "std 27,216(%2)\n"
+ "std 28,224(%2)\n"
+ "std 29,232(%2)\n"
+ "std 30,240(%2)\n"
+ "std 31,248(%2)\n"
+ "mfmsr %0\n"
+ "std %0, 264(%2)\n"
+ "mfctr %0\n"
+ "std %0, 280(%2)\n"
+ "mflr %0\n"
+ "std %0, 288(%2)\n"
+ "bl 1f\n"
+ "1: mflr %1\n"
+ "std %1, 256(%2)\n"
+ "mtlr %0\n"
+ "mfxer %0\n"
+ "std %0, 296(%2)\n"
+ : "=&r" (tmp1), "=&r" (tmp2)
+ : "b" (newregs));
+ }
+}
+#else
+/*
+ * Provide a dummy definition to avoid build failures. Will remain
+ * empty till crash dump support is enabled.
+ */
+static inline void crash_setup_regs(struct pt_regs *newregs,
+ struct pt_regs *oldregs) { }
+#endif /* !__powerpc64 __ */
+
+#ifndef __ASSEMBLY__
#define MAX_NOTE_BYTES 1024
#ifdef __powerpc64__
@@ -53,14 +121,7 @@
extern int default_machine_kexec_prepare(struct kimage *image);
extern void default_machine_crash_shutdown(struct pt_regs *regs);
-#endif /* !CONFIG_KEXEC */
-
-/*
- * Provide a dummy definition to avoid build failures. Will remain
- * empty till crash dump support is enabled.
- */
-static inline void crash_setup_regs(struct pt_regs *newregs,
- struct pt_regs *oldregs) { }
#endif /* ! __ASSEMBLY__ */
+#endif /* CONFIG_KEXEC */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_KEXEC_H */