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Commit 6df10a82 authored by Mark Nutter's avatar Mark Nutter Committed by Paul Mackerras
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[PATCH] spufs: enable SPE problem state MMIO access. 



This patch is layered on top of CONFIG_SPARSEMEM
and is patterned after direct mapping of LS.

This patch allows mmap() of the following regions:
"mfc", which represents the area from [0x3000 - 0x3fff];
"cntl", which represents the area from [0x4000 - 0x4fff];
"signal1" which begins at offset 0x14000; "signal2" which
begins at offset 0x1c000.

The signal1 & signal2 files may be mmap()'d by regular user
processes.  The cntl and mfc file, on the other hand, may
only be accessed if the owning process has CAP_SYS_RAWIO,
because they have the potential to confuse the kernel
with regard to parallel access to the same files with
regular file operations: the kernel always holds a spinlock
when accessing registers in these areas to serialize them,
which can not be guaranteed with user mmaps,

Signed-off-by: default avatarArnd Bergmann <arnd.bergmann@de.ibm.com>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent a33a7d73

arch/powerpc/platforms/cell/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -10,4 +10,9 @@ config SPU_FS 
	  Units on machines implementing the Broadband Processor

	  Architecture.



config SPUFS_MMAP

	bool

	depends on SPU_FS && SPARSEMEM && !PPC_64K_PAGES

	default y



endmenu

arch/powerpc/platforms/cell/spu_base.c

+5 −0
Original line number Diff line number Diff line
@@ -570,6 +570,11 @@ static int __init spu_map_device(struct spu *spu, struct device_node *spe) 
	if (!spu->local_store)

		goto out;



	prop = get_property(spe, "problem", NULL);

	if (!prop)

		goto out_unmap;

	spu->problem_phys = *(unsigned long *)prop;



	spu->problem= map_spe_prop(spe, "problem");

	if (!spu->problem)

		goto out_unmap;

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

+15 −3
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ 
#include <asm/spu_csa.h>

#include "spufs.h"



struct spu_context *alloc_spu_context(struct address_space *local_store)

struct spu_context *alloc_spu_context(void)

{

	struct spu_context *ctx;

	ctx = kmalloc(sizeof *ctx, GFP_KERNEL);
@@ -53,7 +53,10 @@ struct spu_context *alloc_spu_context(struct address_space *local_store) 
	ctx->mfc_fasync = NULL;

	ctx->tagwait = 0;

	ctx->state = SPU_STATE_SAVED;

	ctx->local_store = local_store;

	ctx->local_store = NULL;

	ctx->cntl = NULL;

	ctx->signal1 = NULL;

	ctx->signal2 = NULL;

	ctx->spu = NULL;

	ctx->ops = &spu_backing_ops;

	ctx->owner = get_task_mm(current);
@@ -110,7 +113,16 @@ void spu_release(struct spu_context *ctx) 


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);

	if (ctx->cntl)

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

	if (ctx->signal1)

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

	if (ctx->signal2)

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

}



int spu_acquire_runnable(struct spu_context *ctx)

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

+223 −6
Original line number Diff line number Diff line
@@ -41,8 +41,10 @@ static int 
spufs_mem_open(struct inode *inode, struct file *file)

{

	struct spufs_inode_info *i = SPUFS_I(inode);

	file->private_data = i->i_ctx;

	file->f_mapping = i->i_ctx->local_store;

	struct spu_context *ctx = i->i_ctx;

	file->private_data = ctx;

	file->f_mapping = inode->i_mapping;

	ctx->local_store = inode->i_mapping;

	return 0;

}
@@ -86,7 +88,7 @@ spufs_mem_write(struct file *file, const char __user *buffer, 
	return ret;

}



#ifdef CONFIG_SPARSEMEM

#ifdef CONFIG_SPUFS_MMAP

static struct page *

spufs_mem_mmap_nopage(struct vm_area_struct *vma,

		      unsigned long address, int *type)
@@ -138,11 +140,113 @@ static struct file_operations spufs_mem_fops = { 
	.read    = spufs_mem_read,

	.write   = spufs_mem_write,

	.llseek  = generic_file_llseek,

#ifdef CONFIG_SPARSEMEM

#ifdef CONFIG_SPUFS_MMAP

	.mmap    = spufs_mem_mmap,

#endif

};



#ifdef CONFIG_SPUFS_MMAP

static struct page *spufs_ps_nopage(struct vm_area_struct *vma,

				    unsigned long address,

				    int *type, unsigned long ps_offs)

{

	struct page *page = NOPAGE_SIGBUS;

	int fault_type = VM_FAULT_SIGBUS;

	struct spu_context *ctx = vma->vm_file->private_data;

	unsigned long offset = address - vma->vm_start;

	unsigned long area;

	int ret;



	offset += vma->vm_pgoff << PAGE_SHIFT;

	if (offset >= 0x4000)

		goto out;



	ret = spu_acquire_runnable(ctx);

	if (ret)

		goto out;



	area = ctx->spu->problem_phys + ps_offs;

	page = pfn_to_page((area + offset) >> PAGE_SHIFT);

	fault_type = VM_FAULT_MINOR;

	page_cache_get(page);



	spu_release(ctx);



      out:

	if (type)

		*type = fault_type;



	return page;

}



static struct page *spufs_cntl_mmap_nopage(struct vm_area_struct *vma,

					   unsigned long address, int *type)

{

	return spufs_ps_nopage(vma, address, type, 0x4000);

}



static struct vm_operations_struct spufs_cntl_mmap_vmops = {

	.nopage = spufs_cntl_mmap_nopage,

};



/*

 * mmap support for problem state control area [0x4000 - 0x4fff].

 * Mapping this area requires that the application have CAP_SYS_RAWIO,

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

 */

static int spufs_cntl_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_cntl_mmap_vmops;

	return 0;

}

#endif



static int spufs_cntl_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->cntl = inode->i_mapping;

	return 0;

}



static ssize_t

spufs_cntl_read(struct file *file, char __user *buffer,

		size_t size, loff_t *pos)

{

	/* FIXME: read from spu status */

	return -EINVAL;

}



static ssize_t

spufs_cntl_write(struct file *file, const char __user *buffer,

		 size_t size, loff_t *pos)

{

	/* FIXME: write to runctl bit */

	return -EINVAL;

}



static struct file_operations spufs_cntl_fops = {

	.open = spufs_cntl_open,

	.read = spufs_cntl_read,

	.write = spufs_cntl_write,

#ifdef CONFIG_SPUFS_MMAP

	.mmap = spufs_cntl_mmap,

#endif

};



static int

spufs_regs_open(struct inode *inode, struct file *file)

{
@@ -503,6 +607,16 @@ static struct file_operations spufs_wbox_stat_fops = { 
	.read	= spufs_wbox_stat_read,

};



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;

	return nonseekable_open(inode, file);

}



static ssize_t spufs_signal1_read(struct file *file, char __user *buf,

			size_t len, loff_t *pos)

{
@@ -543,12 +657,50 @@ static ssize_t spufs_signal1_write(struct file *file, const char __user *buf, 
	return 4;

}



#ifdef CONFIG_SPUFS_MMAP

static struct page *spufs_signal1_mmap_nopage(struct vm_area_struct *vma,

					      unsigned long address, int *type)

{

	return spufs_ps_nopage(vma, address, type, 0x14000);

}



static struct vm_operations_struct spufs_signal1_mmap_vmops = {

	.nopage = spufs_signal1_mmap_nopage,

};



static int spufs_signal1_mmap(struct file *file, struct vm_area_struct *vma)

{

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

		return -EINVAL;



	vma->vm_flags |= VM_RESERVED;

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

				     | _PAGE_NO_CACHE);



	vma->vm_ops = &spufs_signal1_mmap_vmops;

	return 0;

}

#endif



static struct file_operations spufs_signal1_fops = {

	.open = spufs_pipe_open,

	.open = spufs_signal1_open,

	.read = spufs_signal1_read,

	.write = spufs_signal1_write,

#ifdef CONFIG_SPUFS_MMAP

	.mmap = spufs_signal1_mmap,

#endif

};



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;

	return nonseekable_open(inode, file);

}



static ssize_t spufs_signal2_read(struct file *file, char __user *buf,

			size_t len, loff_t *pos)

{
@@ -591,10 +743,39 @@ static ssize_t spufs_signal2_write(struct file *file, const char __user *buf, 
	return 4;

}



#ifdef CONFIG_SPUFS_MMAP

static struct page *spufs_signal2_mmap_nopage(struct vm_area_struct *vma,

					      unsigned long address, int *type)

{

	return spufs_ps_nopage(vma, address, type, 0x1c000);

}



static struct vm_operations_struct spufs_signal2_mmap_vmops = {

	.nopage = spufs_signal2_mmap_nopage,

};



static int spufs_signal2_mmap(struct file *file, struct vm_area_struct *vma)

{

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

		return -EINVAL;



	/* FIXME: */

	vma->vm_flags |= VM_RESERVED;

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

				     | _PAGE_NO_CACHE);



	vma->vm_ops = &spufs_signal2_mmap_vmops;

	return 0;

}

#endif



static struct file_operations spufs_signal2_fops = {

	.open = spufs_pipe_open,

	.open = spufs_signal2_open,

	.read = spufs_signal2_read,

	.write = spufs_signal2_write,

#ifdef CONFIG_SPUFS_MMAP

	.mmap = spufs_signal2_mmap,

#endif

};



static void spufs_signal1_type_set(void *data, u64 val)
@@ -643,6 +824,38 @@ 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_mfc_mmap_nopage(struct vm_area_struct *vma,

					   unsigned long address, int *type)

{

	return spufs_ps_nopage(vma, address, type, 0x3000);

}



static struct vm_operations_struct spufs_mfc_mmap_vmops = {

	.nopage = spufs_mfc_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_mfc_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_mfc_mmap_vmops;

	return 0;

}

#endif



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

{
@@ -932,6 +1145,9 @@ static struct file_operations spufs_mfc_fops = { 
	.flush	 = spufs_mfc_flush,

	.fsync	 = spufs_mfc_fsync,

	.fasync	 = spufs_mfc_fasync,

#ifdef CONFIG_SPUFS_MMAP

	.mmap	 = spufs_mfc_mmap,

#endif

};



static void spufs_npc_set(void *data, u64 val)
@@ -1077,6 +1293,7 @@ struct tree_descr spufs_dir_contents[] = { 
	{ "signal1_type", &spufs_signal1_type, 0666, },

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

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

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

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

	{ "fpcr", &spufs_fpcr_fops, 0666, },

	{ "decr", &spufs_decr_ops, 0666, },

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

+1 −1
Original line number Diff line number Diff line
@@ -241,7 +241,7 @@ spufs_mkdir(struct inode *dir, struct dentry *dentry, int mode) 
		inode->i_gid = dir->i_gid;

		inode->i_mode &= S_ISGID;

	}

	ctx = alloc_spu_context(inode->i_mapping);

	ctx = alloc_spu_context();

	SPUFS_I(inode)->i_ctx = ctx;

	if (!ctx)

		goto out_iput;