powerpc/cell: Move spu_handle_mm_fault() out of cell platform

Currently spu_handle_mm_fault() is in the cell platform.

This code is generically useful for other non-cell co-processors on powerpc.

This patch moves this function out of the cell platform into arch/powerpc/mm so
that others may use it.

Signed-off-by: Ian Munsie <imunsie@au1.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/Kconfig

@@ -608,6 +608,10 @@ config PPC_SUBPAGE_PROT
 	  to set access permissions (read/write, readonly, or no access)
 	  on the 4k subpages of each 64k page.
 
+config PPC_COPRO_BASE
+	bool
+	default n
+
 config SCHED_SMT
 	bool "SMT (Hyperthreading) scheduler support"
 	depends on PPC64 && SMP

arch/powerpc/include/asm/copro.h

@@ -0,0 +1,16 @@
+/*
+ * Copyright 2014 IBM Corp.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#ifndef _ASM_POWERPC_COPRO_H
+#define _ASM_POWERPC_COPRO_H
+
+int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
+			  unsigned long dsisr, unsigned *flt);
+
+#endif /* _ASM_POWERPC_COPRO_H */

arch/powerpc/include/asm/spu.h

@@ -27,6 +27,8 @@
 #include <linux/workqueue.h>
 #include <linux/device.h>
 #include <linux/mutex.h>
+#include <asm/reg.h>
+#include <asm/copro.h>
 
 #define LS_SIZE (256 * 1024)
 #define LS_ADDR_MASK (LS_SIZE - 1)
@@ -277,9 +279,6 @@ void spu_remove_dev_attr(struct device_attribute *attr);
 int spu_add_dev_attr_group(struct attribute_group *attrs);
 void spu_remove_dev_attr_group(struct attribute_group *attrs);
 
-int spu_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
-		unsigned long dsisr, unsigned *flt);
-
 /*
  * Notifier blocks:
  *

arch/powerpc/mm/Makefile

@@ -34,3 +34,4 @@ obj-$(CONFIG_TRANSPARENT_HUGEPAGE) += hugepage-hash64.o
 obj-$(CONFIG_PPC_SUBPAGE_PROT)	+= subpage-prot.o
 obj-$(CONFIG_NOT_COHERENT_CACHE) += dma-noncoherent.o
 obj-$(CONFIG_HIGHMEM)		+= highmem.o
+obj-$(CONFIG_PPC_COPRO_BASE)	+= copro_fault.o

arch/powerpc/platforms/cell/spu_fault.c → arch/powerpc/mm/copro_fault.c

@@ -1,5 +1,5 @@
 /*
- * SPU mm fault handler
+ * CoProcessor (SPU/AFU) mm fault handler
  *
  * (C) Copyright IBM Deutschland Entwicklung GmbH 2007
  *
@@ -23,16 +23,14 @@
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/export.h>
-
-#include <asm/spu.h>
-#include <asm/spu_csa.h>
+#include <asm/reg.h>
 
 /*
  * This ought to be kept in sync with the powerpc specific do_page_fault
  * function. Currently, there are a few corner cases that we haven't had
  * to handle fortunately.
  */
-int spu_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
+int copro_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
 		unsigned long dsisr, unsigned *flt)
 {
 	struct vm_area_struct *vma;
@@ -58,12 +56,12 @@ int spu_handle_mm_fault(struct mm_struct *mm, unsigned long ea,
 			goto out_unlock;
 	}
 
-	is_write = dsisr & MFC_DSISR_ACCESS_PUT;
+	is_write = dsisr & DSISR_ISSTORE;
 	if (is_write) {
 		if (!(vma->vm_flags & VM_WRITE))
 			goto out_unlock;
 	} else {
-		if (dsisr & MFC_DSISR_ACCESS_DENIED)
+		if (dsisr & DSISR_PROTFAULT)
 			goto out_unlock;
 		if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
 			goto out_unlock;
@@ -91,4 +89,4 @@ out_unlock:
 	up_read(&mm->mmap_sem);
 	return ret;
 }
-EXPORT_SYMBOL_GPL(spu_handle_mm_fault);
+EXPORT_SYMBOL_GPL(copro_handle_mm_fault);

arch/powerpc/platforms/cell/Kconfig

@@ -86,6 +86,7 @@ config SPU_FS_64K_LS
 config SPU_BASE
 	bool
 	default n
+	select PPC_COPRO_BASE
 
 config CBE_RAS
 	bool "RAS features for bare metal Cell BE"

arch/powerpc/platforms/cell/Makefile

@@ -20,7 +20,7 @@ spu-manage-$(CONFIG_PPC_CELL_COMMON)	+= spu_manage.o
 
 obj-$(CONFIG_SPU_BASE)			+= spu_callbacks.o spu_base.o \
 					   spu_notify.o \
-					   spu_syscalls.o spu_fault.o \
+					   spu_syscalls.o \
 					   $(spu-priv1-y) \
 					   $(spu-manage-y) \
 					   spufs/

arch/powerpc/platforms/cell/spufs/fault.c

@@ -138,7 +138,7 @@ int spufs_handle_class1(struct spu_context *ctx)
 	if (ctx->state == SPU_STATE_RUNNABLE)
 		ctx->spu->stats.hash_flt++;
 
-	/* we must not hold the lock when entering spu_handle_mm_fault */
+	/* we must not hold the lock when entering copro_handle_mm_fault */
 	spu_release(ctx);
 
 	access = (_PAGE_PRESENT | _PAGE_USER);
@@ -149,7 +149,7 @@ int spufs_handle_class1(struct spu_context *ctx)
 
 	/* hashing failed, so try the actual fault handler */
 	if (ret)
-		ret = spu_handle_mm_fault(current->mm, ea, dsisr, &flt);
+		ret = copro_handle_mm_fault(current->mm, ea, dsisr, &flt);
 
 	/*
 	 * This is nasty: we need the state_mutex for all the bookkeeping even