/* do remap by hand */
virtad = &pgindex->buffer[ofs-intofs];
vmf->page = virt_to_page(virtad); /* return page index */
return 0; /* everything went fine */
}
#else /* This is the old nopage method for compatibility reasons */
static struct page *dmar_vm_nopage(struct vm_area_struct * area, unsigned long address, int *nopage_type) {
struct page *page = NOPAGE_SIGBUS; /* for debug, gives mempage */
/* address relative to dma memory */
unsigned long ofs = (address - area->vm_start) + VMA_OFFSET(area);
unsigned long intofs;
unsigned char * virtad = NULL; /* start ad of page in kernel space */
struct dma_page_pointer *pgindex;
/* find right page */
pgindex = dma_main_pointer; /* start with first mem piece */
intofs=0; /* linear offset of current mempiece start */
while (intofs+pgindex->fullsize<=ofs) {
intofs +=pgindex->fullsize;
pgindex=pgindex->next;
if (pgindex == dma_main_pointer) {
*nopage_type = VM_FAULT_SIGBUS; /* new in kernel 2.6 */
return NOPAGE_SIGBUS; /* ofs not mapped */
}
}; /* pgindex contains now the relevant page index */
/* do remap by hand */
virtad = &pgindex->buffer[ofs-intofs];
/* page table index */
page=virt_to_page(virtad);
get_page(page); /* increment page use counter */
*nopage_type = VM_FAULT_MINOR; /* new in kernel 2.6 */
return page;
}
struct page *scullv_vma_nopage(struct vm_area_struct *vma,
unsigned long address, int write)
{
unsigned long offset;
ScullV_Dev *ptr, *dev = scullv_vma_to_dev(vma);
struct page *page = NOPAGE_SIGBUS;
void *pageptr = NULL; /* default to "missing" */
pgd_t *pgd; pmd_t *pmd; pte_t *pte;
unsigned long lpage;
down(&dev->sem);
offset = (address - vma->vm_start) + VMA_OFFSET(vma);
if (offset >= dev->size) goto out; /* out of range */
/*
* Now retrieve the scullv device from the list,then the page.
* If the device has holes, the process receives a SIGBUS when
* accessing the hole.
*/
offset >>= PAGE_SHIFT; /* offset is a number of pages */
for (ptr = dev; ptr && offset >= dev->qset;) {
ptr = ptr->next;
offset -= dev->qset;
}
if (ptr && ptr->data) pageptr = ptr->data[offset];
if (!pageptr) goto out; /* hole or end-of-file */
/*
* After scullv lookup, "page" is now the address of the page
* needed by the current process. Since it's a vmalloc address,
* first retrieve the unsigned long value to be looked up
* in page tables.
*/
lpage = VMALLOC_VMADDR(pageptr);
#ifdef LINUX_24
spin_lock(&init_mm.page_table_lock);
#endif
pgd = pgd_offset(&init_mm, lpage);
pmd = pmd_offset(pgd, lpage);
pte = pte_offset(pmd, lpage);
#ifdef LINUX_24
page = pte_page(*pte);
spin_unlock(&init_mm.page_table_lock);
#else
page = mem_map + MAP_NR(pte_page(*pte));
#endif
/* got it, now increment the count */
get_page(page);
out:
up(&dev->sem);
return page;
}
int scullv_mmap(struct file *filp, struct vm_area_struct *vma)
{
struct inode *inode = INODE_FROM_F(filp);
if (VMA_OFFSET(vma) & (PAGE_SIZE-1))
return -ENXIO; /* need aligned offsets */
/* don't do anything here: "nopage" will fill the holes */
vma->vm_ops = &scullv_vm_ops;
vma->vm_flags |= VM_RESERVED;
#ifdef LINUX_24
vma->vm_private_data = scullv_devices + MINOR(inode->i_rdev);
#else
vma->vm_file = filp;
#endif
scullv_vma_open(vma);
return 0;
}
/* vm_operations, die das eigentliche mmap über die nopage-methode vornehmen */
static struct page *dmar_vm_nopage(struct vm_area_struct * area, unsigned long address, int write_access) {
struct page *page = NOPAGE_SIGBUS; /* for debug, gives mempage */
/* address relative to dma memory */
unsigned long ofs = (address - area->vm_start) + VMA_OFFSET(area);
unsigned long intofs;
unsigned char * virtad = NULL; /* start ad of page in kernel space */
struct dma_page_pointer *pgindex;
#ifdef bla_nopage
void * pga; /* for tests */
#endif
/* pgd_t *pgd; pmd_t *pmd; pte_t *pte; for getting mapping to real bufs
unsigned long lpage; */
/* find right page */
pgindex = dma_main_pointer; /* start with first mem piece */
intofs=0; /* linear offset of current mempiece start */
while (intofs+pgindex->fullsize<=ofs) {
intofs +=pgindex->fullsize;
pgindex=pgindex->next;
if (pgindex == dma_main_pointer) return NOPAGE_SIGBUS; /* ofs not mapped */
}; /* pgindex contains now the relevant page index */
/* do remap by hand */
virtad = &pgindex->buffer[ofs-intofs];
/* virtad = dma_main_pointer->buffer; for tests only */
/* page table index */
page=virt_to_page(virtad);
get_page(page); /* increment page use counter */
#ifdef bla_nopage
pga = page_address(page); /* for tests */
printk("nopage-Zugriff; adr=%x, phys=%x, page=%x\n ofs=%x, intofs=%x, pgindex=%x, virtad = %x, pga= %x\n",
(int)address, (int)pgindex->physbuf,(int)page,(int)ofs,
(int)intofs,(int)pgindex, (int)virtad, (int) pga);
#endif
return page;
}
/* don't do anything here: "nopage" will fill the holes */
vma->vm_ops = &scullv_vm_ops;
vma->vm_flags |= VM_RESERVED;
#ifdef LINUX_24
vma->vm_private_data = scullv_devices + MINOR(inode->i_rdev);
#else
vma->vm_file = filp;
#endif
scullv_vma_open(vma);
return 0;
}
#else /* LINUX_20 */
int scullv_mmap(struct inode *inode, struct file *filp,
struct vm_area_struct *vma)
{
if (VMA_OFFSET(vma) & (PAGE_SIZE-1))
return -ENXIO; /* need aligned offsets */
/*
* A pointer to init_mm is needed to access page tables
*/
if (!init_mm_ptr)
retrieve_init_mm_ptr();
/* don't do anything here: "nopage" will fill the holes */
vma->vm_ops = &scullv_vm_ops;
vma->vm_inode = inode;
inode->i_count++;
scullv_vma_open(vma);
return 0;
}
