Commit c74a804f authored by Dmitry Kalinkin's avatar Dmitry Kalinkin Committed by Greg Kroah-Hartman
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staging: vme: mmap() support for vme_user 



We also make sure that user won't be able to reconfigure the window while it is
mmap'ed.

Signed-off-by: default avatarDmitry Kalinkin <dmitry.kalinkin@gmail.com>
Cc: Martyn Welch <martyn.welch@ge.com>
Cc: Igor Alekseev <igor.alekseev@itep.ru>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0cd189a4

drivers/staging/vme/devices/vme_user.c

+85 −0
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 


#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt



#include <linux/atomic.h>

#include <linux/cdev.h>

#include <linux/delay.h>

#include <linux/device.h>
@@ -99,6 +100,7 @@ struct image_desc { 
	struct device *device;	/* Sysfs device */

	struct vme_resource *resource;	/* VME resource */

	int users;		/* Number of current users */

	int mmap_count;		/* Number of current mmap's */

};

static struct image_desc image[VME_DEVS];
@@ -134,6 +136,10 @@ static ssize_t vme_user_write(struct file *, const char __user *, size_t, 
	loff_t *);

static loff_t vme_user_llseek(struct file *, loff_t, int);

static long vme_user_unlocked_ioctl(struct file *, unsigned int, unsigned long);

static int vme_user_mmap(struct file *file, struct vm_area_struct *vma);



static void vme_user_vm_open(struct vm_area_struct *vma);

static void vme_user_vm_close(struct vm_area_struct *vma);



static int vme_user_match(struct vme_dev *);

static int vme_user_probe(struct vme_dev *);
@@ -147,6 +153,17 @@ static const struct file_operations vme_user_fops = { 
	.llseek = vme_user_llseek,

	.unlocked_ioctl = vme_user_unlocked_ioctl,

	.compat_ioctl = vme_user_unlocked_ioctl,

	.mmap = vme_user_mmap,

};



struct vme_user_vma_priv {

	unsigned int minor;

	atomic_t refcnt;

};



static const struct vm_operations_struct vme_user_vm_ops = {

	.open = vme_user_vm_open,

	.close = vme_user_vm_close,

};
@@ -488,6 +505,11 @@ static int vme_user_ioctl(struct inode *inode, struct file *file, 


		case VME_SET_MASTER:



			if (image[minor].mmap_count != 0) {

				pr_warn("Can't adjust mapped window\n");

				return -EPERM;

			}



			copied = copy_from_user(&master, argp, sizeof(master));

			if (copied != 0) {

				pr_warn("Partial copy from userspace\n");
@@ -564,6 +586,69 @@ vme_user_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 
	return ret;

}



static void vme_user_vm_open(struct vm_area_struct *vma)

{

	struct vme_user_vma_priv *vma_priv = vma->vm_private_data;



	atomic_inc(&vma_priv->refcnt);

}



static void vme_user_vm_close(struct vm_area_struct *vma)

{

	struct vme_user_vma_priv *vma_priv = vma->vm_private_data;

	unsigned int minor = vma_priv->minor;



	if (!atomic_dec_and_test(&vma_priv->refcnt))

		return;



	mutex_lock(&image[minor].mutex);

	image[minor].mmap_count--;

	mutex_unlock(&image[minor].mutex);



	kfree(vma_priv);

}



static int vme_user_master_mmap(unsigned int minor, struct vm_area_struct *vma)

{

	int err;

	struct vme_user_vma_priv *vma_priv;



	mutex_lock(&image[minor].mutex);



	err = vme_master_mmap(image[minor].resource, vma);

	if (err) {

		mutex_unlock(&image[minor].mutex);

		return err;

	}



	vma_priv = kmalloc(sizeof(struct vme_user_vma_priv), GFP_KERNEL);

	if (vma_priv == NULL) {

		mutex_unlock(&image[minor].mutex);

		return -ENOMEM;

	}



	vma_priv->minor = minor;

	atomic_set(&vma_priv->refcnt, 1);

	vma->vm_ops = &vme_user_vm_ops;

	vma->vm_private_data = vma_priv;



	image[minor].mmap_count++;



	mutex_unlock(&image[minor].mutex);



	return 0;

}



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

{

	unsigned int minor = MINOR(file_inode(file)->i_rdev);



	if (type[minor] == MASTER_MINOR)

		return vme_user_master_mmap(minor, vma);



	return -ENODEV;

}





/*

 * Unallocate a previously allocated buffer

drivers/vme/vme.c

+26 −0
Original line number Diff line number Diff line
@@ -609,6 +609,32 @@ unsigned int vme_master_rmw(struct vme_resource *resource, unsigned int mask, 
}

EXPORT_SYMBOL(vme_master_rmw);



int vme_master_mmap(struct vme_resource *resource, struct vm_area_struct *vma)

{

	struct vme_master_resource *image;

	phys_addr_t phys_addr;

	unsigned long vma_size;



	if (resource->type != VME_MASTER) {

		pr_err("Not a master resource\n");

		return -EINVAL;

	}



	image = list_entry(resource->entry, struct vme_master_resource, list);

	phys_addr = image->bus_resource.start + (vma->vm_pgoff << PAGE_SHIFT);

	vma_size = vma->vm_end - vma->vm_start;



	if (phys_addr + vma_size > image->bus_resource.end + 1) {

		pr_err("Map size cannot exceed the window size\n");

		return -EFAULT;

	}



	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);



	return vm_iomap_memory(vma, phys_addr, vma->vm_end - vma->vm_start);

}

EXPORT_SYMBOL(vme_master_mmap);



void vme_master_free(struct vme_resource *resource)

{

	struct vme_master_resource *master_image;

include/linux/vme.h

+1 −0
Original line number Diff line number Diff line
@@ -137,6 +137,7 @@ ssize_t vme_master_read(struct vme_resource *, void *, size_t, loff_t); 
ssize_t vme_master_write(struct vme_resource *, void *, size_t, loff_t);

unsigned int vme_master_rmw(struct vme_resource *, unsigned int, unsigned int,

	unsigned int, loff_t);

int vme_master_mmap(struct vme_resource *resource, struct vm_area_struct *vma);

void vme_master_free(struct vme_resource *);



struct vme_resource *vme_dma_request(struct vme_dev *, u32);