[PATCH] powerpc: Merge thread_info.h

Merge ppc32 and ppc64 versions of thread_info.h.  They were pretty
similar already, the chief changes are:

	- Instead of inline asm to implement current_thread_info(),
which needs to be different for ppc32 and ppc64, we use C with an
asm("r1") register variable.  gcc turns it into the same asm as we
used to have for both platforms.
	- We replace ppc32's 'local_flags' with the ppc64
'syscall_noerror' field.  The noerror flag was in fact the only thing
in the local_flags field anyway, so the ppc64 approach is simpler, and
means we only need a load-immediate/store instead of load/mask/store
when clearing the flag.
	- In readiness for 64k pages, when THREAD_SIZE will be less
than a page, ppc64 used kmalloc() rather than get_free_pages() to
allocate the kernel stack.  With this patch we do the same for ppc32,
since there's no strong reason not to.
	- For ppc64, we no longer export THREAD_SHIFT and THREAD_SIZE
via asm-offsets, thread_info.h can now be safely included in asm, as
on ppc32.

Built and booted on G4 Powerbook (ARCH=ppc and ARCH=powerpc) and
Power5 (ARCH=ppc64 and ARCH=powerpc).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 5 insertions, 6 deletions

diff --git a/arch/ppc/kernel/asm-offsets.c b/arch/ppc/kernel/asm-offsets.c
index 7972db1f6570..968261d69572 100644
--- a/arch/ppc/kernel/asm-offsets.c
+++ b/arch/ppc/kernel/asm-offsets.c
@@ -130,10 +130,10 @@ main(void)
         DEFINE(CPU_SPEC_FEATURES, offsetof(struct cpu_spec, cpu_features));
         DEFINE(CPU_SPEC_SETUP, offsetof(struct cpu_spec, cpu_setup));
 
+        DEFINE(TI_SC_NOERR, offsetof(struct thread_info, syscall_noerror));
         DEFINE(TI_TASK, offsetof(struct thread_info, task));
         DEFINE(TI_EXECDOMAIN, offsetof(struct thread_info, exec_domain));
         DEFINE(TI_FLAGS, offsetof(struct thread_info, flags));
-        DEFINE(TI_LOCAL_FLAGS, offsetof(struct thread_info, local_flags));
         DEFINE(TI_CPU, offsetof(struct thread_info, cpu));
         DEFINE(TI_PREEMPT, offsetof(struct thread_info, preempt_count));
 
diff --git a/arch/ppc/kernel/entry.S b/arch/ppc/kernel/entry.S
index 68fc61221776..f044edbb454f 100644
--- a/arch/ppc/kernel/entry.S
+++ b/arch/ppc/kernel/entry.S
@@ -200,9 +200,8 @@ _GLOBAL(DoSyscall)
         bl      do_show_syscall
 #endif /* SHOW_SYSCALLS */
         rlwinm  r10,r1,0,0,18   /* current_thread_info() */
-        lwz     r11,TI_LOCAL_FLAGS(r10)
-        rlwinm  r11,r11,0,~_TIFL_FORCE_NOERROR
-        stw     r11,TI_LOCAL_FLAGS(r10)
+        li      r11,0
+        stb     r11,TI_SC_NOERR(r10)
         lwz     r11,TI_FLAGS(r10)
         andi.   r11,r11,_TIF_SYSCALL_T_OR_A
         bne-    syscall_dotrace
@@ -227,8 +226,8 @@ ret_from_syscall:
         cmplw   0,r3,r11
         rlwinm  r12,r1,0,0,18   /* current_thread_info() */
         blt+    30f
-        lwz     r11,TI_LOCAL_FLAGS(r12)
-        andi.   r11,r11,_TIFL_FORCE_NOERROR
+        lbz     r11,TI_SC_NOERR(r12)
+        cmpwi   r11,0
         bne     30f
         neg     r3,r3
         lwz     r10,_CCR(r1)    /* Set SO bit in CR */