Merge tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system

Pull "Disintegrate and delete asm/system.h" from David Howells:
 "Here are a bunch of patches to disintegrate asm/system.h into a set of
  separate bits to relieve the problem of circular inclusion
  dependencies.

  I've built all the working defconfigs from all the arches that I can
  and made sure that they don't break.

  The reason for these patches is that I recently encountered a circular
  dependency problem that came about when I produced some patches to
  optimise get_order() by rewriting it to use ilog2().

  This uses bitops - and on the SH arch asm/bitops.h drags in
  asm-generic/get_order.h by a circuituous route involving asm/system.h.

  The main difficulty seems to be asm/system.h.  It holds a number of
  low level bits with no/few dependencies that are commonly used (eg.
  memory barriers) and a number of bits with more dependencies that
  aren't used in many places (eg.  switch_to()).

  These patches break asm/system.h up into the following core pieces:

    (1) asm/barrier.h

        Move memory barriers here.  This already done for MIPS and Alpha.

    (2) asm/switch_to.h

        Move switch_to() and related stuff here.

    (3) asm/exec.h

        Move arch_align_stack() here.  Other process execution related bits
        could perhaps go here from asm/processor.h.

    (4) asm/cmpxchg.h

        Move xchg() and cmpxchg() here as they're full word atomic ops and
        frequently used by atomic_xchg() and atomic_cmpxchg().

    (5) asm/bug.h

        Move die() and related bits.

    (6) asm/auxvec.h

        Move AT_VECTOR_SIZE_ARCH here.

  Other arch headers are created as needed on a per-arch basis."

Fixed up some conflicts from other header file cleanups and moving code
around that has happened in the meantime, so David's testing is somewhat
weakened by that.  We'll find out anything that got broken and fix it..

* tag 'split-asm_system_h-for-linus-20120328' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-asm_system: (38 commits)
  Delete all instances of asm/system.h
  Remove all #inclusions of asm/system.h
  Add #includes needed to permit the removal of asm/system.h
  Move all declarations of free_initmem() to linux/mm.h
  Disintegrate asm/system.h for OpenRISC
  Split arch_align_stack() out from asm-generic/system.h
  Split the switch_to() wrapper out of asm-generic/system.h
  Move the asm-generic/system.h xchg() implementation to asm-generic/cmpxchg.h
  Create asm-generic/barrier.h
  Make asm-generic/cmpxchg.h #include asm-generic/cmpxchg-local.h
  Disintegrate asm/system.h for Xtensa
  Disintegrate asm/system.h for Unicore32 [based on ver #3, changed by gxt]
  Disintegrate asm/system.h for Tile
  Disintegrate asm/system.h for Sparc
  Disintegrate asm/system.h for SH
  Disintegrate asm/system.h for Score
  Disintegrate asm/system.h for S390
  Disintegrate asm/system.h for PowerPC
  Disintegrate asm/system.h for PA-RISC
  Disintegrate asm/system.h for MN10300
  ...

1 files changed, 106 insertions, 0 deletions

diff --git a/arch/sparc/include/asm/switch_to_32.h b/arch/sparc/include/asm/switch_to_32.h
new file mode 100644
index 000000000000..e32e82b76eed
--- /dev/null
+++ b/arch/sparc/include/asm/switch_to_32.h
@@ -0,0 +1,106 @@
+#ifndef __SPARC_SWITCH_TO_H
+#define __SPARC_SWITCH_TO_H
+
+#include <asm/smp.h>
+
+extern struct thread_info *current_set[NR_CPUS];
+
+/*
+ * Flush windows so that the VM switch which follows
+ * would not pull the stack from under us.
+ *
+ * SWITCH_ENTER and SWITH_DO_LAZY_FPU do not work yet (e.g. SMP does not work)
+ * XXX WTF is the above comment? Found in late teen 2.4.x.
+ */
+#ifdef CONFIG_SMP
+#define SWITCH_ENTER(prv) \
+	do {			\
+	if (test_tsk_thread_flag(prv, TIF_USEDFPU)) { \
+		put_psr(get_psr() | PSR_EF); \
+		fpsave(&(prv)->thread.float_regs[0], &(prv)->thread.fsr, \
+		       &(prv)->thread.fpqueue[0], &(prv)->thread.fpqdepth); \
+		clear_tsk_thread_flag(prv, TIF_USEDFPU); \
+		(prv)->thread.kregs->psr &= ~PSR_EF; \
+	} \
+	} while(0)
+
+#define SWITCH_DO_LAZY_FPU(next)	/* */
+#else
+#define SWITCH_ENTER(prv)		/* */
+#define SWITCH_DO_LAZY_FPU(nxt)	\
+	do {			\
+	if (last_task_used_math != (nxt))		\
+		(nxt)->thread.kregs->psr&=~PSR_EF;	\
+	} while(0)
+#endif
+
+#define prepare_arch_switch(next) do { \
+	__asm__ __volatile__( \
+	".globl\tflush_patch_switch\nflush_patch_switch:\n\t" \
+	"save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \
+	"save %sp, -0x40, %sp; save %sp, -0x40, %sp; save %sp, -0x40, %sp\n\t" \
+	"save %sp, -0x40, %sp\n\t" \
+	"restore; restore; restore; restore; restore; restore; restore"); \
+} while(0)
+
+	/* Much care has gone into this code, do not touch it.
+	 *
+	 * We need to loadup regs l0/l1 for the newly forked child
+	 * case because the trap return path relies on those registers
+	 * holding certain values, gcc is told that they are clobbered.
+	 * Gcc needs registers for 3 values in and 1 value out, so we
+	 * clobber every non-fixed-usage register besides l2/l3/o4/o5.  -DaveM
+	 *
+	 * Hey Dave, that do not touch sign is too much of an incentive
+	 * - Anton & Pete
+	 */
+#define switch_to(prev, next, last) do {						\
+	SWITCH_ENTER(prev);								\
+	SWITCH_DO_LAZY_FPU(next);							\
+	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next->active_mm));		\
+	__asm__ __volatile__(								\
+	"sethi	%%hi(here - 0x8), %%o7\n\t"						\
+	"mov	%%g6, %%g3\n\t"								\
+	"or	%%o7, %%lo(here - 0x8), %%o7\n\t"					\
+	"rd	%%psr, %%g4\n\t"							\
+	"std	%%sp, [%%g6 + %4]\n\t"							\
+	"rd	%%wim, %%g5\n\t"							\
+	"wr	%%g4, 0x20, %%psr\n\t"							\
+	"nop\n\t"									\
+	"std	%%g4, [%%g6 + %3]\n\t"							\
+	"ldd	[%2 + %3], %%g4\n\t"							\
+	"mov	%2, %%g6\n\t"								\
+	".globl	patchme_store_new_current\n"						\
+"patchme_store_new_current:\n\t"							\
+	"st	%2, [%1]\n\t"								\
+	"wr	%%g4, 0x20, %%psr\n\t"							\
+	"nop\n\t"									\
+	"nop\n\t"									\
+	"nop\n\t"	/* LEON needs all 3 nops: load to %sp depends on CWP. */		\
+	"ldd	[%%g6 + %4], %%sp\n\t"							\
+	"wr	%%g5, 0x0, %%wim\n\t"							\
+	"ldd	[%%sp + 0x00], %%l0\n\t"						\
+	"ldd	[%%sp + 0x38], %%i6\n\t"						\
+	"wr	%%g4, 0x0, %%psr\n\t"							\
+	"nop\n\t"									\
+	"nop\n\t"									\
+	"jmpl	%%o7 + 0x8, %%g0\n\t"							\
+	" ld	[%%g3 + %5], %0\n\t"							\
+	"here:\n"									\
+        : "=&r" (last)									\
+        : "r" (&(current_set[hard_smp_processor_id()])),	\
+	  "r" (task_thread_info(next)),				\
+	  "i" (TI_KPSR),					\
+	  "i" (TI_KSP),						\
+	  "i" (TI_TASK)						\
+	:       "g1", "g2", "g3", "g4", "g5",       "g7",	\
+	  "l0", "l1",       "l3", "l4", "l5", "l6", "l7",	\
+	  "i0", "i1", "i2", "i3", "i4", "i5",			\
+	  "o0", "o1", "o2", "o3",                   "o7");	\
+	} while(0)
+
+extern void fpsave(unsigned long *fpregs, unsigned long *fsr,
+		   void *fpqueue, unsigned long *fpqdepth);
+extern void synchronize_user_stack(void);
+
+#endif /* __SPARC_SWITCH_TO_H */