[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>

1 files changed, 73 insertions, 12 deletions

diff --git a/include/asm-powerpc/kexec.h b/include/asm-powerpc/kexec.h
index fffdf690b840..640a6459f2f4 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 void default_machine_kexec(struct kimage *image);
 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 */