[SPARC64]: Make smp_processor_id() functional before start_kernel()

Uses of smp_processor_id() get pushed earlier and earlier in
the start_kernel() sequence.  So just get it working before
we call start_kernel() to avoid all possible problems.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 30 insertions, 0 deletions

diff --git a/arch/sparc64/kernel/head.S b/arch/sparc64/kernel/head.S
index 3eadac5e171e..31c5892f5acc 100644
--- a/arch/sparc64/kernel/head.S
+++ b/arch/sparc64/kernel/head.S
@@ -10,6 +10,7 @@
 #include <linux/config.h>
 #include <linux/version.h>
 #include <linux/errno.h>
+#include <linux/threads.h>
 #include <asm/thread_info.h>
 #include <asm/asi.h>
 #include <asm/pstate.h>
@@ -493,6 +494,35 @@ tlb_fixup_done:
         call    prom_init
          mov    %l7, %o0                        ! OpenPROM cif handler
 
+        /* Initialize current_thread_info()->cpu as early as possible.
+         * In order to do that accurately we have to patch up the get_cpuid()
+         * assembler sequences.  And that, in turn, requires that we know
+         * if we are on a Starfire box or not.  While we're here, patch up
+         * the sun4v sequences as well.
+         */
+        call    check_if_starfire
+         nop
+        call    per_cpu_patch
+         nop
+        call    sun4v_patch
+         nop
+
+#ifdef CONFIG_SMP
+        call    hard_smp_processor_id
+         nop
+        cmp     %o0, NR_CPUS
+        blu,pt  %xcc, 1f
+         nop
+        call    boot_cpu_id_too_large
+         nop
+        /* Not reached... */
+
+1:
+#else
+        mov     0, %o0
+#endif
+        stb     %o0, [%g6 + TI_CPU]
+
         /* Off we go.... */
         call    start_kernel
          nop