1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
|
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/sysfs.h>
#include <asm/atomic.h>
#include <linux/pagemap.h>
#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/scatterlist.h>
#include <linux/vmalloc.h>
#include <linux/stat.h>
#include <linux/interrupt.h>
#include <linux/wait.h>
#include "base.h"
/**
*
* Called when an application open()s a /dev/fpga*, attaches the private data
* with the file pointer.
*
*/
static int pcidriver_open(struct inode *inode, struct file *filp)
{
pcidriver_privdata_t *privdata;
/* Set the private data area for the file */
privdata = container_of( inode->i_cdev, pcidriver_privdata_t, cdev);
filp->private_data = privdata;
pcidriver_module_get(privdata);
return 0;
}
/**
*
* Called when the application close()s the file descriptor. Does nothing at
* the moment.
*
*/
static int pcidriver_release(struct inode *inode, struct file *filp)
{
pcidriver_privdata_t *privdata;
/* Get the private data area */
privdata = filp->private_data;
pcidriver_module_put(privdata);
return 0;
}
/*************************************************************************/
/* Internal driver functions */
static int pcidriver_mmap_bar(pcidriver_privdata_t *privdata, struct vm_area_struct *vmap, int bar)
{
#ifdef PCIDRIVER_DUMMY_DEVICE
return -ENXIO;
#else /* PCIDRIVER_DUMMY_DEVICE */
int ret = 0;
unsigned long bar_addr;
unsigned long bar_length, vma_size;
unsigned long bar_flags;
mod_info_dbg("Entering mmap_pci\n");
/* Get info of the BAR to be mapped */
bar_addr = pci_resource_start(privdata->pdev, bar);
bar_length = pci_resource_len(privdata->pdev, bar);
bar_flags = pci_resource_flags(privdata->pdev, bar);
/* Check sizes */
vma_size = (vmap->vm_end - vmap->vm_start);
if ((vma_size != bar_length) &&
((bar_length < PAGE_SIZE) && (vma_size != PAGE_SIZE))) {
mod_info( "mmap size is not correct! bar: %lu - vma: %lu\n", bar_length, vma_size );
return -EINVAL;
}
if (bar_flags & IORESOURCE_IO) {
/* Unlikely case, we will mmap a IO region */
/* IO regions are never cacheable */
vmap->vm_page_prot = pgprot_noncached(vmap->vm_page_prot);
/* Map the BAR */
ret = io_remap_pfn_range(vmap, vmap->vm_start, (bar_addr >> PAGE_SHIFT), bar_length, vmap->vm_page_prot);
} else {
/* Normal case, mmap a memory region */
/* Ensure this VMA is non-cached, if it is not flaged as prefetchable.
* If it is prefetchable, caching is allowed and will give better performance.
* This should be set properly by the BIOS, but we want to be sure. */
/* adapted from drivers/char/mem.c, mmap function. */
/* Setting noncached disables MTRR registers, and we want to use them.
* So we take this code out. This can lead to caching problems if and only if
* the System BIOS set something wrong. Check LDDv3, page 425.
*/
// if (!(bar_flags & IORESOURCE_PREFETCH))
// vmap->vm_page_prot = pgprot_noncached(vmap->vm_page_prot);
/* Map the BAR */
ret = remap_pfn_range(vmap, vmap->vm_start, (bar_addr >> PAGE_SHIFT), bar_length, vmap->vm_page_prot);
}
if (ret) {
mod_info("remap_pfn_range failed\n");
return -EAGAIN;
}
return 0; /* success */
#endif /* PCIDRIVER_DUMMY_DEVICE */
}
/**
*
* This function is the entry point for mmap() and calls either pcidriver_mmap_bar
* or pcidriver_mmap_kmem
*
* @see pcidriver_mmap_bar
* @see pcidriver_mmap_kmem
*
*/
static int pcidriver_mmap(struct file *filp, struct vm_area_struct *vma)
{
pcidriver_privdata_t *privdata;
int ret = 0, bar;
mod_info_dbg("Entering mmap\n");
/* Get the private data area */
privdata = filp->private_data;
/* Check the current mmap mode */
switch (privdata->mmap_mode) {
case PCIDRIVER_MMAP_PCI:
bar = privdata->mmap_area;
if ((bar < 0)||(bar > 5)) {
mod_info("Attempted to mmap a PCI area with the wrong mmap_area value: %d\n",privdata->mmap_area);
return -EINVAL;
}
ret = pcidriver_mmap_bar(privdata, vma, bar);
break;
case PCIDRIVER_MMAP_KMEM:
ret = pcidriver_mmap_kmem(privdata, vma);
break;
default:
mod_info( "Invalid mmap_mode value (%d)\n",privdata->mmap_mode );
return -EINVAL; /* Invalid parameter (mode) */
}
return ret;
}
static struct file_operations pcidriver_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = pcidriver_ioctl,
.mmap = pcidriver_mmap,
.open = pcidriver_open,
.release = pcidriver_release,
};
const struct file_operations *pcidriver_get_fops(void)
{
return &pcidriver_fops;
}
void pcidriver_module_get(pcidriver_privdata_t *privdata) {
atomic_inc(&(privdata->refs));
// mod_info("Ref: %i\n", atomic_read(&(privdata->refs)));
}
void pcidriver_module_put(pcidriver_privdata_t *privdata) {
if (atomic_add_negative(-1, &(privdata->refs))) {
atomic_inc(&(privdata->refs));
mod_info("Reference counting error...");
} else {
// mod_info("Unref: %i\n", atomic_read(&(privdata->refs)));
}
}
|
