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-rw-r--r--arch/sparc64/kernel/head.S25
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/sparc64/kernel/head.S b/arch/sparc64/kernel/head.S
index c4147ad8677..44b105c04dd 100644
--- a/arch/sparc64/kernel/head.S
+++ b/arch/sparc64/kernel/head.S
@@ -632,11 +632,36 @@ tlb_fixup_done:
/* Not reached... */
1:
+ /* If we boot on a non-zero cpu, all of the per-cpu
+ * variable references we make before setting up the
+ * per-cpu areas will use a bogus offset. Put a
+ * compensating factor into __per_cpu_base to handle
+ * this cleanly.
+ *
+ * What the per-cpu code calculates is:
+ *
+ * __per_cpu_base + (cpu << __per_cpu_shift)
+ *
+ * These two variables are zero initially, so to
+ * make it all cancel out to zero we need to put
+ * "0 - (cpu << 0)" into __per_cpu_base so that the
+ * above formula evaluates to zero.
+ *
+ * We cannot even perform a printk() until this stuff
+ * is setup as that calls cpu_clock() which uses
+ * per-cpu variables.
+ */
+ sub %g0, %o0, %o1
+ sethi %hi(__per_cpu_base), %o2
+ stx %o1, [%o2 + %lo(__per_cpu_base)]
#else
mov 0, %o0
#endif
sth %o0, [%g6 + TI_CPU]
+ call prom_init_report
+ nop
+
/* Off we go.... */
call start_kernel
nop