[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 */