/*
* Alloc "coherent" memory, which for OpenRISC means simply uncached.
*
* This function effectively just calls __get_free_pages, sets the
* cache-inhibit bit on those pages, and makes sure that the pages are
* flushed out of the cache before they are used.
*
* If the NON_CONSISTENT attribute is set, then this function just
* returns "normal", cachable memory.
*
* There are additional flags WEAK_ORDERING and WRITE_COMBINE to take
* into consideration here, too. All current known implementations of
* the OR1K support only strongly ordered memory accesses, so that flag
* is being ignored for now; uncached but write-combined memory is a
* missing feature of the OR1K.
*/
void *
arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
gfp_t gfp, unsigned long attrs)
{
unsigned long va;
void *page;
struct mm_walk walk = {
.pte_entry = page_set_nocache,
.mm = &init_mm
};
page = alloc_pages_exact(size, gfp);
if (!page)
return NULL;
/* This gives us the real physical address of the first page. */
*dma_handle = __pa(page);
va = (unsigned long)page;
if ((attrs & DMA_ATTR_NON_CONSISTENT) == 0) {
/*
* We need to iterate through the pages, clearing the dcache for
* them and setting the cache-inhibit bit.
*/
if (walk_page_range(va, va + size, &walk)) {
free_pages_exact(page, size);
return NULL;
}
}
return (void *)va;
}
void *or1k_dma_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp)
{
unsigned long va;
void *page;
struct mm_walk walk = {
.pte_entry = page_set_nocache,
.mm = &init_mm
};
page = alloc_pages_exact(size, gfp);
if (!page)
return NULL;
*dma_handle = __pa(page);
va = (unsigned long)page;
if (walk_page_range(va, va + size, &walk)) {
free_pages_exact(page, size);
return NULL;
}
return (void *)va;
}
static int pagemap_read() {
pm_len = PM_ENTRY_BYTES * NUM_ENTRIES;
pm_buffer = malloc(pm_len);
if (!pm_buffer)
return -ENOMEM;
pm_pos = 0;
walk_page_range();
return 0;
}
void or1k_dma_free_coherent(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle)
{
unsigned long va = (unsigned long)vaddr;
struct mm_walk walk = {
.pte_entry = page_clear_nocache,
.mm = &init_mm
};
/* walk_page_range shouldn't be able to fail here */
WARN_ON(walk_page_range(va, va + size, &walk));
free_pages_exact(vaddr, size);
}
void
arch_dma_free(struct device *dev, size_t size, void *vaddr,
dma_addr_t dma_handle, unsigned long attrs)
{
unsigned long va = (unsigned long)vaddr;
struct mm_walk walk = {
.pte_entry = page_clear_nocache,
.mm = &init_mm
};
if ((attrs & DMA_ATTR_NON_CONSISTENT) == 0) {
/* walk_page_range shouldn't be able to fail here */
WARN_ON(walk_page_range(va, va + size, &walk));
}
free_pages_exact(vaddr, size);
}
static ssize_t clear_refs_write(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
struct task_struct *task;
char buffer[PROC_NUMBUF];
struct mm_struct *mm;
struct vm_area_struct *vma;
enum clear_refs_types type;
int itype;
int rv;
memset(buffer, 0, sizeof(buffer));
if (count > sizeof(buffer) - 1)
count = sizeof(buffer) - 1;
if (copy_from_user(buffer, buf, count))
return -EFAULT;
rv = kstrtoint(strstrip(buffer), 10, &itype);
if (rv < 0)
return rv;
type = (enum clear_refs_types)itype;
if (type < CLEAR_REFS_ALL || type >= CLEAR_REFS_LAST)
return -EINVAL;
if (type == CLEAR_REFS_SOFT_DIRTY) {
soft_dirty_cleared = true;
pr_warn_once("The pagemap bits 55-60 has changed their meaning!"
" See the linux/Documentation/vm/pagemap.txt for "
"details.\n");
}
task = get_proc_task(file_inode(file));
if (!task)
return -ESRCH;
mm = get_task_mm(task);
if (mm) {
struct clear_refs_private cp = {
.type = type,
};
struct mm_walk clear_refs_walk = {
.pmd_entry = clear_refs_pte_range,
.test_walk = clear_refs_test_walk,
.mm = mm,
.private = &cp,
};
if (type == CLEAR_REFS_MM_HIWATER_RSS) {
/*
* Writing 5 to /proc/pid/clear_refs resets the peak
* resident set size to this mm's current rss value.
*/
down_write(&mm->mmap_sem);
reset_mm_hiwater_rss(mm);
up_write(&mm->mmap_sem);
goto out_mm;
}
down_read(&mm->mmap_sem);
if (type == CLEAR_REFS_SOFT_DIRTY) {
for (vma = mm->mmap; vma; vma = vma->vm_next) {
if (!(vma->vm_flags & VM_SOFTDIRTY))
continue;
up_read(&mm->mmap_sem);
down_write(&mm->mmap_sem);
for (vma = mm->mmap; vma; vma = vma->vm_next) {
vma->vm_flags &= ~VM_SOFTDIRTY;
vma_set_page_prot(vma);
}
downgrade_write(&mm->mmap_sem);
break;
}
mmu_notifier_invalidate_range_start(mm, 0, -1);
}
walk_page_range(0, ~0UL, &clear_refs_walk);
if (type == CLEAR_REFS_SOFT_DIRTY)
mmu_notifier_invalidate_range_end(mm, 0, -1);
flush_tlb_mm(mm);
up_read(&mm->mmap_sem);
out_mm:
mmput(mm);
}
put_task_struct(task);
return count;
}
