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Commit d9379c4b authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Paul Mackerras
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[POWERPC] spufs: restore mapping of mssync register 



A recent change to the way that the mfc file gets mapped made it
impossible to map the SPE Multi-Source Synchronization register
into user space, but that may be needed by some applications.

This restores the missing functionality.

Signed-off-by: default avatarArnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent 91edfa49

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

+50 −0
Original line number Diff line number Diff line
@@ -824,6 +824,55 @@ static u64 spufs_signal2_type_get(void *data) 
DEFINE_SIMPLE_ATTRIBUTE(spufs_signal2_type, spufs_signal2_type_get,

					spufs_signal2_type_set, "%llu");



#ifdef CONFIG_SPUFS_MMAP

static struct page *spufs_mss_mmap_nopage(struct vm_area_struct *vma,

					   unsigned long address, int *type)

{

	return spufs_ps_nopage(vma, address, type, 0x0000);

}



static struct vm_operations_struct spufs_mss_mmap_vmops = {

	.nopage = spufs_mss_mmap_nopage,

};



/*

 * mmap support for problem state MFC DMA area [0x0000 - 0x0fff].

 * Mapping this area requires that the application have CAP_SYS_RAWIO,

 * as these registers require special care when read/writing.

 */

static int spufs_mss_mmap(struct file *file, struct vm_area_struct *vma)

{

	if (!(vma->vm_flags & VM_SHARED))

		return -EINVAL;



	if (!capable(CAP_SYS_RAWIO))

		return -EPERM;



	vma->vm_flags |= VM_RESERVED;

	vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)

				     | _PAGE_NO_CACHE);



	vma->vm_ops = &spufs_mss_mmap_vmops;

	return 0;

}

#endif



static int spufs_mss_open(struct inode *inode, struct file *file)

{

	struct spufs_inode_info *i = SPUFS_I(inode);



	file->private_data = i->i_ctx;

	return nonseekable_open(inode, file);

}



static struct file_operations spufs_mss_fops = {

	.open	 = spufs_mss_open,

#ifdef CONFIG_SPUFS_MMAP

	.mmap	 = spufs_mss_mmap,

#endif

};





#ifdef CONFIG_SPUFS_MMAP

static struct page *spufs_mfc_mmap_nopage(struct vm_area_struct *vma,

					   unsigned long address, int *type)
@@ -1292,6 +1341,7 @@ struct tree_descr spufs_dir_contents[] = { 
	{ "signal2", &spufs_signal2_fops, 0666, },

	{ "signal1_type", &spufs_signal1_type, 0666, },

	{ "signal2_type", &spufs_signal2_type, 0666, },

	{ "mss", &spufs_mss_fops, 0666, },

	{ "mfc", &spufs_mfc_fops, 0666, },

	{ "cntl", &spufs_cntl_fops,  0666, },

	{ "npc", &spufs_npc_ops, 0666, },