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Message-Id: <1416008178-9393-3-git-send-email-dmitry.kalinkin@gmail.com>
Date: Sat, 15 Nov 2014 02:36:17 +0300
From: Dmitry Kalinkin <dmitry.kalinkin@...il.com>
To: devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org
Cc: Martyn Welch <martyn.welch@...com>,
Manohar Vanga <manohar.vanga@...il.com>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
Igor Alekseev <igor.alekseev@...p.ru>,
Dmitry Kalinkin <dmitry.kalinkin@...il.com>
Subject: [PATCH 2/3] 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: Dmitry Kalinkin <dmitry.kalinkin@...il.com>
Cc: Igor Alekseev <igor.alekseev@...p.ru>
---
drivers/staging/vme/devices/vme_user.c | 85 ++++++++++++++++++++++++++++++++++
drivers/vme/vme.c | 26 +++++++++++
include/linux/vme.h | 1 +
3 files changed, 112 insertions(+)
diff --git a/drivers/staging/vme/devices/vme_user.c b/drivers/staging/vme/devices/vme_user.c
index 8731838..b7fe1f0 100644
--- a/drivers/staging/vme/devices/vme_user.c
+++ b/drivers/staging/vme/devices/vme_user.c
@@ -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->f_dentry->d_inode->i_rdev);
+
+ if (type[minor] == MASTER_MINOR)
+ return vme_user_master_mmap(minor, vma);
+
+ return -ENODEV;
+}
+
/*
* Unallocate a previously allocated buffer
diff --git a/drivers/vme/vme.c b/drivers/vme/vme.c
index 7516030..3dc62b4 100644
--- a/drivers/vme/vme.c
+++ b/drivers/vme/vme.c
@@ -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) {
+ printk(KERN_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) {
+ printk(KERN_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;
diff --git a/include/linux/vme.h b/include/linux/vme.h
index 8cd6f19..79242e9 100644
--- a/include/linux/vme.h
+++ b/include/linux/vme.h
@@ -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);
--
1.9.1
--
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