unsigned long l4x_clear_user(void *address, unsigned long n)
{
unsigned long clear_size = (unsigned long)address & ~PAGE_MASK;
#ifdef DEBUG_MEMCPY_TOFS
printk("%s called from: %08lx to: %p, len: %08lx\n",
__func__, *((unsigned long *)&address - 1), address, n);
#endif
if (segment_eq(get_fs(), KERNEL_DS)) {
if (L4X_CHECK_IN_KERNEL_ACCESS && l4x_check_kern_region(address, n, 1))
return -EFAULT;
memset(address, 0, n);
return 0;
}
if (clear_size) {
clear_size = min(PAGE_SIZE - clear_size, n);
if (__clear_user_page(address, clear_size) == -EFAULT)
return n;
n -= clear_size;
}
while (n) {
address += clear_size;
clear_size = min(PAGE_SIZE, n);
if (__clear_user_page(address, clear_size) == -EFAULT)
return n;
n -= clear_size;
}
return 0;
}
/*
* clear_user_page
* @to: kernel logical address
* @address: U0 address to be mapped
* @page: page (virt_to_page(to))
*/
void clear_user_page(void *to, unsigned long address, struct page *page)
{
void __clear_page_wb(void *to);
if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
__clear_page_wb(to);
else {
pgprot_t pgprot = __pgprot(_PAGE_PRESENT |
_PAGE_RW | _PAGE_CACHABLE |
_PAGE_DIRTY | _PAGE_ACCESSED |
_PAGE_HW_SHARED | _PAGE_FLAGS_HARD);
unsigned long phys_addr = virt_to_phys(to);
unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
pgd_t *pgd = pgd_offset_k(p3_addr);
pud_t *pud = pud_offset(pgd, p3_addr);
pmd_t *pmd = pmd_offset(pud, p3_addr);
pte_t *pte = pte_offset_kernel(pmd, p3_addr);
pte_t entry;
unsigned long flags;
entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot);
inc_preempt_count();
BUG_ON(atomic_inc_return(&concurreny_check[(address & CACHE_ALIAS)>>12]) != 1);
set_pte(pte, entry);
local_irq_save(flags);
flush_tlb_one(get_asid(), p3_addr);
local_irq_restore(flags);
update_mmu_cache(NULL, p3_addr, entry);
__clear_user_page((void *)p3_addr, to);
pte_clear(&init_mm, p3_addr, pte);
atomic_dec(&concurreny_check[(address & CACHE_ALIAS)>>12]);
dec_preempt_count();
}
}
/*
* clear_user_page
* @to: P1 address
* @address: U0 address to be mapped
* @page: page (virt_to_page(to))
*/
void clear_user_page(void *to, unsigned long address, struct page *page)
{
__set_bit(PG_mapped, &page->flags);
if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
clear_page(to);
else {
unsigned long phys_addr = PHYSADDR(to);
unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
pgd_t *pgd = pgd_offset_k(p3_addr);
pud_t *pud = pud_offset(pgd, p3_addr);
pmd_t *pmd = pmd_offset(pud, p3_addr);
pte_t *pte = pte_offset_kernel(pmd, p3_addr);
pte_t entry;
unsigned long flags;
entry = pfn_pte(phys_addr >> PAGE_SHIFT, PAGE_KERNEL);
mutex_lock(&p3map_mutex[(address & CACHE_ALIAS)>>12]);
set_pte(pte, entry);
local_irq_save(flags);
__flush_tlb_page(get_asid(), p3_addr);
local_irq_restore(flags);
update_mmu_cache(NULL, p3_addr, entry);
__clear_user_page((void *)p3_addr, to);
pte_clear(&init_mm, p3_addr, pte);
mutex_unlock(&p3map_mutex[(address & CACHE_ALIAS)>>12]);
}
}
/*
* clear_user_page
* @to: P1 address
* @address: U0 address to be mapped
* @page: page (virt_to_page(to))
*/
void clear_user_page(void *to, unsigned long address, struct page *page)
{
__set_bit(PG_mapped, &page->flags);
if (((address ^ (unsigned long)to) & CACHE_ALIAS) == 0)
clear_page(to);
else {
pgprot_t pgprot = __pgprot(_PAGE_PRESENT |
_PAGE_RW | _PAGE_CACHABLE |
_PAGE_DIRTY | _PAGE_ACCESSED |
_PAGE_HW_SHARED | _PAGE_FLAGS_HARD);
unsigned long phys_addr = PHYSADDR(to);
unsigned long p3_addr = P3SEG + (address & CACHE_ALIAS);
pgd_t *dir = pgd_offset_k(p3_addr);
pmd_t *pmd = pmd_offset(dir, p3_addr);
pte_t *pte = pte_offset_kernel(pmd, p3_addr);
pte_t entry;
unsigned long flags;
entry = pfn_pte(phys_addr >> PAGE_SHIFT, pgprot);
down(&p3map_sem[(address & CACHE_ALIAS)>>12]);
set_pte(pte, entry);
local_irq_save(flags);
__flush_tlb_page(get_asid(), p3_addr);
local_irq_restore(flags);
update_mmu_cache(NULL, p3_addr, entry);
__clear_user_page((void *)p3_addr, to);
pte_clear(&init_mm, p3_addr, pte);
up(&p3map_sem[(address & CACHE_ALIAS)>>12]);
}
}
