Subject: Re: [PATCH v4 01/16] powerpc/cell: Move spu_handle_mm_fault() out of cell platform

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Thu, 09 Oct 2014 20:31:37 +0530

Michael Neuling <[email-masked]> writes:

> From: Ian Munsie <[email-masked]>
>
> 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.
>

Reviewed-by: Aneesh Kumar K.V <[email-masked]>

> Signed-off-by: Ian Munsie <[email-masked]>
> Signed-off-by: Michael Neuling <[email-masked]>
> ---
>  arch/powerpc/Kconfig                                     |  4 ++++
>  arch/powerpc/include/asm/copro.h                         | 16 ++++++++++++++++
>  arch/powerpc/include/asm/spu.h                           |  5 ++---
>  arch/powerpc/mm/Makefile                                 |  1 +
>  .../{platforms/cell/spu_fault.c => mm/copro_fault.c}     | 14 ++++++--------
>  arch/powerpc/platforms/cell/Kconfig                      |  1 +
>  arch/powerpc/platforms/cell/Makefile                     |  2 +-
>  arch/powerpc/platforms/cell/spufs/fault.c                |  4 ++--
>  8 files changed, 33 insertions(+), 14 deletions(-)
>  create mode 100644 arch/powerpc/include/asm/copro.h
>  rename arch/powerpc/{platforms/cell/spu_fault.c => mm/copro_fault.c} (89%)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 4bc7b62..8f094e9 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -603,6 +603,10 @@ 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
> diff --git a/arch/powerpc/include/asm/copro.h b/arch/powerpc/include/asm/copro.h
> new file mode 100644
> index 0000000..51cae85
> --- /dev/null
> +++ b/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 */
> diff --git a/arch/powerpc/include/asm/spu.h b/arch/powerpc/include/asm/spu.h
> index 37b7ca3..a6e6e2b 100644
> --- a/arch/powerpc/include/asm/spu.h
> +++ b/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:
>   *
> diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile
> index d0130ff..325e861 100644
> --- a/arch/powerpc/mm/Makefile
> +++ b/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
> diff --git a/arch/powerpc/platforms/cell/spu_fault.c b/arch/powerpc/mm/copro_fault.c
> similarity index 89%
> rename from arch/powerpc/platforms/cell/spu_fault.c
> rename to arch/powerpc/mm/copro_fault.c
> index 641e727..ba7df14 100644
> --- a/arch/powerpc/platforms/cell/spu_fault.c
> +++ b/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);
> diff --git a/arch/powerpc/platforms/cell/Kconfig b/arch/powerpc/platforms/cell/Kconfig
> index 9978f59..870b6db 100644
> --- a/arch/powerpc/platforms/cell/Kconfig
> +++ b/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"
> diff --git a/arch/powerpc/platforms/cell/Makefile b/arch/powerpc/platforms/cell/Makefile
> index fe053e7..2d16884 100644
> --- a/arch/powerpc/platforms/cell/Makefile
> +++ b/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/
> diff --git a/arch/powerpc/platforms/cell/spufs/fault.c b/arch/powerpc/platforms/cell/spufs/fault.c
> index 8cb6260..e45894a 100644
> --- a/arch/powerpc/platforms/cell/spufs/fault.c
> +++ b/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
> -- 
> 1.9.1
>
> --
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