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Commit 17e0e270 authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Paul Mackerras
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[POWERPC] spufs: Fix bitrot of the SPU mmap facility 



It looks like we've had some serious bitrot there mostly due to tracking
of address_space's of mmap'ed files getting out of sync with the actual
mmap code. The mfc, mss and psmap were not tracked properly and thus
not invalidated on context switches (oops !)

I also removed the various file->f_mapping = inode->i_mapping;
assignments that were done in the other open() routines since that
is already done for us by __dentry_open.

One improvement we might want to do later is to assign the various
ctx-> fields at mmap time instead of file open/close time so that we
don't call unmap_mapping_range() on thing that have not been mmap'ed

Finally, I added some smp_wmb's after assigning the ctx-> fields to make
sure they are visible to other CPUs. I don't think this is really
necessary as I suspect locking in the fs layer will make that happen
anyway but better safe than sorry.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 44430e0d

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

+8 −4
Original line number Diff line number Diff line
@@ -111,13 +111,17 @@ void spu_unmap_mappings(struct spu_context *ctx) 
	if (ctx->local_store)

		unmap_mapping_range(ctx->local_store, 0, LS_SIZE, 1);

	if (ctx->mfc)

		unmap_mapping_range(ctx->mfc, 0, 0x4000, 1);

		unmap_mapping_range(ctx->mfc, 0, 0x1000, 1);

	if (ctx->cntl)

		unmap_mapping_range(ctx->cntl, 0, 0x4000, 1);

		unmap_mapping_range(ctx->cntl, 0, 0x1000, 1);

	if (ctx->signal1)

		unmap_mapping_range(ctx->signal1, 0, 0x4000, 1);

		unmap_mapping_range(ctx->signal1, 0, PAGE_SIZE, 1);

	if (ctx->signal2)

		unmap_mapping_range(ctx->signal2, 0, 0x4000, 1);

		unmap_mapping_range(ctx->signal2, 0, PAGE_SIZE, 1);

	if (ctx->mss)

		unmap_mapping_range(ctx->mss, 0, 0x1000, 1);

	if (ctx->psmap)

		unmap_mapping_range(ctx->psmap, 0, 0x20000, 1);

}



int spu_acquire_exclusive(struct spu_context *ctx)

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

+12 −4
Original line number Diff line number Diff line
@@ -45,8 +45,8 @@ spufs_mem_open(struct inode *inode, struct file *file) 
	struct spufs_inode_info *i = SPUFS_I(inode);

	struct spu_context *ctx = i->i_ctx;

	file->private_data = ctx;

	file->f_mapping = inode->i_mapping;

	ctx->local_store = inode->i_mapping;

	smp_wmb();

	return 0;

}
@@ -232,8 +232,8 @@ static int spufs_cntl_open(struct inode *inode, struct file *file) 
	struct spu_context *ctx = i->i_ctx;



	file->private_data = ctx;

	file->f_mapping = inode->i_mapping;

	ctx->cntl = inode->i_mapping;

	smp_wmb();

	return simple_attr_open(inode, file, spufs_cntl_get,

					spufs_cntl_set, "0x%08lx");

}
@@ -717,8 +717,8 @@ static int spufs_signal1_open(struct inode *inode, struct file *file) 
	struct spufs_inode_info *i = SPUFS_I(inode);

	struct spu_context *ctx = i->i_ctx;

	file->private_data = ctx;

	file->f_mapping = inode->i_mapping;

	ctx->signal1 = inode->i_mapping;

	smp_wmb();

	return nonseekable_open(inode, file);

}
@@ -824,8 +824,8 @@ static int spufs_signal2_open(struct inode *inode, struct file *file) 
	struct spufs_inode_info *i = SPUFS_I(inode);

	struct spu_context *ctx = i->i_ctx;

	file->private_data = ctx;

	file->f_mapping = inode->i_mapping;

	ctx->signal2 = inode->i_mapping;

	smp_wmb();

	return nonseekable_open(inode, file);

}
@@ -1021,8 +1021,11 @@ static int spufs_mss_mmap(struct file *file, struct vm_area_struct *vma) 
static int spufs_mss_open(struct inode *inode, struct file *file)

{

	struct spufs_inode_info *i = SPUFS_I(inode);

	struct spu_context *ctx = i->i_ctx;



	file->private_data = i->i_ctx;

	ctx->mss = inode->i_mapping;

	smp_wmb();

	return nonseekable_open(inode, file);

}
@@ -1060,8 +1063,11 @@ static int spufs_psmap_mmap(struct file *file, struct vm_area_struct *vma) 
static int spufs_psmap_open(struct inode *inode, struct file *file)

{

	struct spufs_inode_info *i = SPUFS_I(inode);

	struct spu_context *ctx = i->i_ctx;



	file->private_data = i->i_ctx;

	ctx->psmap = inode->i_mapping;

	smp_wmb();

	return nonseekable_open(inode, file);

}
@@ -1114,6 +1120,8 @@ static int spufs_mfc_open(struct inode *inode, struct file *file) 
		return -EBUSY;



	file->private_data = ctx;

	ctx->mfc = inode->i_mapping;

	smp_wmb();

	return nonseekable_open(inode, file);

}

arch/powerpc/platforms/cell/spufs/spufs.h

+2 −0
Original line number Diff line number Diff line
@@ -51,6 +51,8 @@ struct spu_context { 
	struct address_space *cntl; 	   /* 'control' area mappings. */

	struct address_space *signal1; 	   /* 'signal1' area mappings. */

	struct address_space *signal2; 	   /* 'signal2' area mappings. */

	struct address_space *mss; 	   /* 'mss' area mappings. */

	struct address_space *psmap; 	   /* 'psmap' area mappings. */

	u64 object_id;		   /* user space pointer for oprofile */



	enum { SPU_STATE_RUNNABLE, SPU_STATE_SAVED } state;