parisc: Move thread_info into task struct

This implements the CONFIG_THREAD_INFO_IN_TASK option.

With this change:
- before thread_info was part of the stack and located at the beginning of the stack
- now the thread_info struct is moved and located inside the task_struct structure
- the stack is allocated and handled like the major other platforms
- drop the cpu field of thread_info and use instead the one in task_struct

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sven Schnelle <svens@stackframe.org>

1 files changed, 17 insertions, 2 deletions

diff --git a/arch/parisc/include/asm/smp.h b/arch/parisc/include/asm/smp.h
index b9a18db4b05a..16d41127500e 100644
--- a/arch/parisc/include/asm/smp.h
+++ b/arch/parisc/include/asm/smp.h
@@ -34,8 +34,23 @@ extern void arch_send_call_function_ipi_mask(const struct cpumask *mask);
 
 #endif /* !ASSEMBLY */
 
-#define raw_smp_processor_id()	(current_thread_info()->cpu)
-
+/*
+ * This is particularly ugly: it appears we can't actually get the definition
+ * of task_struct here, but we need access to the CPU this task is running on.
+ * Instead of using task_struct we're using TASK_CPU which is extracted from
+ * asm-offsets.h by kbuild to get the current processor ID.
+ *
+ * This also needs to be safeguarded when building asm-offsets.s because at
+ * that time TASK_CPU is not defined yet. It could have been guarded by
+ * TASK_CPU itself, but we want the build to fail if TASK_CPU is missing
+ * when building something else than asm-offsets.s
+ */
+#ifdef GENERATING_ASM_OFFSETS
+#define raw_smp_processor_id()		(0)
+#else
+#include <asm/asm-offsets.h>
+#define raw_smp_processor_id()		(*(unsigned int *)((void *)current + TASK_CPU))
+#endif
 #else /* CONFIG_SMP */
 
 static inline void smp_send_all_nop(void) { return; }