Re: [patch 4/4] spufs: convert nopfn to fault

[Nick Piggin <npiggin@suse.de>]

Thanks for helping out with merging these Andrew. The problem with
this is that these nopfn conversions won't work unless the
BUG_ON is removed from mm/memory.c (patch 1/ that I sent you). So
there is a little dependency chain here. I guess you could send
that patch 1 upstream ASAP, and then let the subsequent non trivial
patches filter up in their own time. I don't know, just a heads up.

On Wed, May 14, 2008 at 04:12:54PM -0700, Andrew Morton wrote:
> From: Nick Piggin <npiggin@suse.de>
> 
> spufs: convert nopfn to fault
> 
> Signed-off-by: Nick Piggin <npiggin@suse.de>
> Acked-by: Jeremy Kerr <jk@ozlabs.org>
> Cc: Paul Mackerras <paulus@samba.org>
> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
> ---
> 
>  arch/powerpc/platforms/cell/spufs/file.c     |   98 ++++++++---------
>  arch/powerpc/platforms/cell/spufs/sputrace.c |    8 -
>  2 files changed, 54 insertions(+), 52 deletions(-)
> 
> diff -puN arch/powerpc/platforms/cell/spufs/file.c~spufs-convert-nopfn-to-fault arch/powerpc/platforms/cell/spufs/file.c
> --- a/arch/powerpc/platforms/cell/spufs/file.c~spufs-convert-nopfn-to-fault
> +++ a/arch/powerpc/platforms/cell/spufs/file.c
> @@ -237,11 +237,13 @@ spufs_mem_write(struct file *file, const
>  	return size;
>  }
>  
> -static unsigned long spufs_mem_mmap_nopfn(struct vm_area_struct *vma,
> -					  unsigned long address)
> +static int
> +spufs_mem_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  {
>  	struct spu_context *ctx	= vma->vm_file->private_data;
> -	unsigned long pfn, offset, addr0 = address;
> +	unsigned long address = (unsigned long)vmf->virtual_address;
> +	unsigned long pfn, offset;
> +
>  #ifdef CONFIG_SPU_FS_64K_LS
>  	struct spu_state *csa = &ctx->csa;
>  	int psize;
> @@ -259,15 +261,15 @@ static unsigned long spufs_mem_mmap_nopf
>  	}
>  #endif /* CONFIG_SPU_FS_64K_LS */
>  
> -	offset = (address - vma->vm_start) + (vma->vm_pgoff << PAGE_SHIFT);
> +	offset = vmf->pgoff << PAGE_SHIFT;
>  	if (offset >= LS_SIZE)
> -		return NOPFN_SIGBUS;
> +		return VM_FAULT_SIGBUS;
>  
> -	pr_debug("spufs_mem_mmap_nopfn address=0x%lx -> 0x%lx, offset=0x%lx\n",
> -		 addr0, address, offset);
> +	pr_debug("spufs_mem_mmap_fault address=0x%lx, offset=0x%lx\n",
> +			address, offset);
>  
>  	if (spu_acquire(ctx))
> -		return NOPFN_REFAULT;
> +		return VM_FAULT_NOPAGE;
>  
>  	if (ctx->state == SPU_STATE_SAVED) {
>  		vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
> @@ -282,12 +284,12 @@ static unsigned long spufs_mem_mmap_nopf
>  
>  	spu_release(ctx);
>  
> -	return NOPFN_REFAULT;
> +	return VM_FAULT_NOPAGE;
>  }
>  
>  
>  static struct vm_operations_struct spufs_mem_mmap_vmops = {
> -	.nopfn = spufs_mem_mmap_nopfn,
> +	.fault = spufs_mem_mmap_fault,
>  };
>  
>  static int spufs_mem_mmap(struct file *file, struct vm_area_struct *vma)
> @@ -350,20 +352,19 @@ static const struct file_operations spuf
>  #endif
>  };
>  
> -static unsigned long spufs_ps_nopfn(struct vm_area_struct *vma,
> -				    unsigned long address,
> +static int spufs_ps_fault(struct vm_area_struct *vma,
> +				    struct vm_fault *vmf,
>  				    unsigned long ps_offs,
>  				    unsigned long ps_size)
>  {
>  	struct spu_context *ctx = vma->vm_file->private_data;
> -	unsigned long area, offset = address - vma->vm_start;
> +	unsigned long area, offset = vmf->pgoff << PAGE_SHIFT;
>  	int ret = 0;
>  
> -	spu_context_nospu_trace(spufs_ps_nopfn__enter, ctx);
> +	spu_context_nospu_trace(spufs_ps_fault__enter, ctx);
>  
> -	offset += vma->vm_pgoff << PAGE_SHIFT;
>  	if (offset >= ps_size)
> -		return NOPFN_SIGBUS;
> +		return VM_FAULT_SIGBUS;
>  
>  	/*
>  	 * Because we release the mmap_sem, the context may be destroyed while
> @@ -377,7 +378,7 @@ static unsigned long spufs_ps_nopfn(stru
>  	 * pages to hand out to the user, but we don't want to wait
>  	 * with the mmap_sem held.
>  	 * It is possible to drop the mmap_sem here, but then we need
> -	 * to return NOPFN_REFAULT because the mappings may have
> +	 * to return VM_FAULT_NOPAGE because the mappings may have
>  	 * hanged.
>  	 */
>  	if (spu_acquire(ctx))
> @@ -385,14 +386,15 @@ static unsigned long spufs_ps_nopfn(stru
>  
>  	if (ctx->state == SPU_STATE_SAVED) {
>  		up_read(&current->mm->mmap_sem);
> -		spu_context_nospu_trace(spufs_ps_nopfn__sleep, ctx);
> +		spu_context_nospu_trace(spufs_ps_fault__sleep, ctx);
>  		ret = spufs_wait(ctx->run_wq, ctx->state == SPU_STATE_RUNNABLE);
> -		spu_context_trace(spufs_ps_nopfn__wake, ctx, ctx->spu);
> +		spu_context_trace(spufs_ps_fault__wake, ctx, ctx->spu);
>  		down_read(&current->mm->mmap_sem);
>  	} else {
>  		area = ctx->spu->problem_phys + ps_offs;
> -		vm_insert_pfn(vma, address, (area + offset) >> PAGE_SHIFT);
> -		spu_context_trace(spufs_ps_nopfn__insert, ctx, ctx->spu);
> +		vm_insert_pfn(vma, (unsigned long)vmf->virtual_address,
> +					(area + offset) >> PAGE_SHIFT);
> +		spu_context_trace(spufs_ps_fault__insert, ctx, ctx->spu);
>  	}
>  
>  	if (!ret)
> @@ -400,18 +402,18 @@ static unsigned long spufs_ps_nopfn(stru
>  
>  refault:
>  	put_spu_context(ctx);
> -	return NOPFN_REFAULT;
> +	return VM_FAULT_NOPAGE;
>  }
>  
>  #if SPUFS_MMAP_4K
> -static unsigned long spufs_cntl_mmap_nopfn(struct vm_area_struct *vma,
> -					   unsigned long address)
> +static int spufs_cntl_mmap_fault(struct vm_area_struct *vma,
> +					   struct vm_fault *vmf)
>  {
> -	return spufs_ps_nopfn(vma, address, 0x4000, 0x1000);
> +	return spufs_ps_fault(vma, vmf, 0x4000, 0x1000);
>  }
>  
>  static struct vm_operations_struct spufs_cntl_mmap_vmops = {
> -	.nopfn = spufs_cntl_mmap_nopfn,
> +	.fault = spufs_cntl_mmap_fault,
>  };
>  
>  /*
> @@ -1096,23 +1098,23 @@ static ssize_t spufs_signal1_write(struc
>  	return 4;
>  }
>  
> -static unsigned long spufs_signal1_mmap_nopfn(struct vm_area_struct *vma,
> -					      unsigned long address)
> +static int
> +spufs_signal1_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  {
>  #if PAGE_SIZE == 0x1000
> -	return spufs_ps_nopfn(vma, address, 0x14000, 0x1000);
> +	return spufs_ps_fault(vma, vmf, 0x14000, 0x1000);
>  #elif PAGE_SIZE == 0x10000
>  	/* For 64k pages, both signal1 and signal2 can be used to mmap the whole
>  	 * signal 1 and 2 area
>  	 */
> -	return spufs_ps_nopfn(vma, address, 0x10000, 0x10000);
> +	return spufs_ps_fault(vma, vmf, 0x10000, 0x10000);
>  #else
>  #error unsupported page size
>  #endif
>  }
>  
>  static struct vm_operations_struct spufs_signal1_mmap_vmops = {
> -	.nopfn = spufs_signal1_mmap_nopfn,
> +	.fault = spufs_signal1_mmap_fault,
>  };
>  
>  static int spufs_signal1_mmap(struct file *file, struct vm_area_struct *vma)
> @@ -1233,23 +1235,23 @@ static ssize_t spufs_signal2_write(struc
>  }
>  
>  #if SPUFS_MMAP_4K
> -static unsigned long spufs_signal2_mmap_nopfn(struct vm_area_struct *vma,
> -					      unsigned long address)
> +static int
> +spufs_signal2_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  {
>  #if PAGE_SIZE == 0x1000
> -	return spufs_ps_nopfn(vma, address, 0x1c000, 0x1000);
> +	return spufs_ps_fault(vma, vmf, 0x1c000, 0x1000);
>  #elif PAGE_SIZE == 0x10000
>  	/* For 64k pages, both signal1 and signal2 can be used to mmap the whole
>  	 * signal 1 and 2 area
>  	 */
> -	return spufs_ps_nopfn(vma, address, 0x10000, 0x10000);
> +	return spufs_ps_fault(vma, vmf, 0x10000, 0x10000);
>  #else
>  #error unsupported page size
>  #endif
>  }
>  
>  static struct vm_operations_struct spufs_signal2_mmap_vmops = {
> -	.nopfn = spufs_signal2_mmap_nopfn,
> +	.fault = spufs_signal2_mmap_fault,
>  };
>  
>  static int spufs_signal2_mmap(struct file *file, struct vm_area_struct *vma)
> @@ -1361,14 +1363,14 @@ DEFINE_SPUFS_ATTRIBUTE(spufs_signal2_typ
>  		       spufs_signal2_type_set, "%llu\n", SPU_ATTR_ACQUIRE);
>  
>  #if SPUFS_MMAP_4K
> -static unsigned long spufs_mss_mmap_nopfn(struct vm_area_struct *vma,
> -					  unsigned long address)
> +static int
> +spufs_mss_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  {
> -	return spufs_ps_nopfn(vma, address, 0x0000, 0x1000);
> +	return spufs_ps_fault(vma, vmf, 0x0000, 0x1000);
>  }
>  
>  static struct vm_operations_struct spufs_mss_mmap_vmops = {
> -	.nopfn = spufs_mss_mmap_nopfn,
> +	.fault = spufs_mss_mmap_fault,
>  };
>  
>  /*
> @@ -1423,14 +1425,14 @@ static const struct file_operations spuf
>  	.mmap	 = spufs_mss_mmap,
>  };
>  
> -static unsigned long spufs_psmap_mmap_nopfn(struct vm_area_struct *vma,
> -					    unsigned long address)
> +static int
> +spufs_psmap_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  {
> -	return spufs_ps_nopfn(vma, address, 0x0000, 0x20000);
> +	return spufs_ps_fault(vma, vmf, 0x0000, 0x20000);
>  }
>  
>  static struct vm_operations_struct spufs_psmap_mmap_vmops = {
> -	.nopfn = spufs_psmap_mmap_nopfn,
> +	.fault = spufs_psmap_mmap_fault,
>  };
>  
>  /*
> @@ -1483,14 +1485,14 @@ static const struct file_operations spuf
>  
>  
>  #if SPUFS_MMAP_4K
> -static unsigned long spufs_mfc_mmap_nopfn(struct vm_area_struct *vma,
> -					  unsigned long address)
> +static int
> +spufs_mfc_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
>  {
> -	return spufs_ps_nopfn(vma, address, 0x3000, 0x1000);
> +	return spufs_ps_fault(vma, vmf, 0x3000, 0x1000);
>  }
>  
>  static struct vm_operations_struct spufs_mfc_mmap_vmops = {
> -	.nopfn = spufs_mfc_mmap_nopfn,
> +	.fault = spufs_mfc_mmap_fault,
>  };
>  
>  /*
> diff -puN arch/powerpc/platforms/cell/spufs/sputrace.c~spufs-convert-nopfn-to-fault arch/powerpc/platforms/cell/spufs/sputrace.c
> --- a/arch/powerpc/platforms/cell/spufs/sputrace.c~spufs-convert-nopfn-to-fault
> +++ a/arch/powerpc/platforms/cell/spufs/sputrace.c
> @@ -182,10 +182,10 @@ struct spu_probe spu_probes[] = {
>  	{ "spu_yield__enter", "ctx %p", spu_context_nospu_event },
>  	{ "spu_deactivate__enter", "ctx %p", spu_context_nospu_event },
>  	{ "__spu_deactivate__unload", "ctx %p spu %p", spu_context_event },
> -	{ "spufs_ps_nopfn__enter", "ctx %p", spu_context_nospu_event },
> -	{ "spufs_ps_nopfn__sleep", "ctx %p", spu_context_nospu_event },
> -	{ "spufs_ps_nopfn__wake", "ctx %p spu %p", spu_context_event },
> -	{ "spufs_ps_nopfn__insert", "ctx %p spu %p", spu_context_event },
> +	{ "spufs_ps_fault__enter", "ctx %p", spu_context_nospu_event },
> +	{ "spufs_ps_fault__sleep", "ctx %p", spu_context_nospu_event },
> +	{ "spufs_ps_fault__wake", "ctx %p spu %p", spu_context_event },
> +	{ "spufs_ps_fault__insert", "ctx %p spu %p", spu_context_event },
>  	{ "spu_acquire_saved__enter", "ctx %p", spu_context_nospu_event },
>  	{ "destroy_spu_context__enter", "ctx %p", spu_context_nospu_event },
>  	{ "spufs_stop_callback__enter", "ctx %p spu %p", spu_context_event },
> _