[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 (file)
--- a/arch/powerpc/kernel/crash.c
+++ b/arch/powerpc/kernel/crash.c
@@ -84,7 +84,10 @@ static void crash_save_this_cpu(struct pt_regs *regs, int cpu)
         * 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 @@ static void crash_save_this_cpu(struct pt_regs *regs, int cpu)
        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(&regs, saved_regs, sizeof(regs));
-       else
-               crash_get_current_regs(&regs);
-       crash_save_this_cpu(&regs, cpu);
-}
-
 #ifdef CONFIG_SMP
 static atomic_t waiting_for_crash_ipi;
 
@@ -260,5 +193,5 @@ void default_machine_crash_shutdown(struct pt_regs *regs)
         */
        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 (file)
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -605,7 +605,8 @@ static void __init early_cmdline_parse(void)
        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 (file)
--- 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 */