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/* arch/sparc64/mm/tlb.c
*
* Copyright (C) 2004 David S. Miller <davem@redhat.com>
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/percpu.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/preempt.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
#include <asm/tlb.h>
/* Heavily inspired by the ppc64 code. */
static DEFINE_PER_CPU(struct tlb_batch, tlb_batch);
void flush_tlb_pending(void)
{
struct tlb_batch *tb = &get_cpu_var(tlb_batch);
struct mm_struct *mm = tb->mm;
if (!tb->tlb_nr)
goto out;
flush_tsb_user(tb);
if (CTX_VALID(mm->context)) {
if (tb->tlb_nr == 1) {
global_flush_tlb_page(mm, tb->vaddrs[0]);
} else {
#ifdef CONFIG_SMP
smp_flush_tlb_pending(tb->mm, tb->tlb_nr,
&tb->vaddrs[0]);
#else
__flush_tlb_pending(CTX_HWBITS(tb->mm->context),
tb->tlb_nr, &tb->vaddrs[0]);
#endif
}
}
tb->tlb_nr = 0;
out:
put_cpu_var(tlb_batch);
}
void arch_enter_lazy_mmu_mode(void)
{
struct tlb_batch *tb = &__get_cpu_var(tlb_batch);
tb->active = 1;
}
void arch_leave_lazy_mmu_mode(void)
{
struct tlb_batch *tb = &__get_cpu_var(tlb_batch);
if (tb->tlb_nr)
flush_tlb_pending();
tb->active = 0;
}
static void tlb_batch_add_one(struct mm_struct *mm, unsigned long vaddr,
bool exec)
{
struct tlb_batch *tb = &get_cpu_var(tlb_batch);
unsigned long nr;
vaddr &= PAGE_MASK;
if (exec)
vaddr |= 0x1UL;
nr = tb->tlb_nr;
if (unlikely(nr != 0 && mm != tb->mm)) {
flush_tlb_pending();
nr = 0;
}
if (!tb->active) {
flush_tsb_user_page(mm, vaddr);
global_flush_tlb_page(mm, vaddr);
goto out;
}
if (nr == 0)
tb->mm = mm;
tb->vaddrs[nr] = vaddr;
tb->tlb_nr = ++nr;
if (nr >= TLB_BATCH_NR)
flush_tlb_pending();
out:
put_cpu_var(tlb_batch);
}
void tlb_batch_add(struct mm_struct *mm, unsigned long vaddr,
pte_t *ptep, pte_t orig, int fullmm)
{
if (tlb_type != hypervisor &&
pte_dirty(orig)) {
unsigned long paddr, pfn = pte_pfn(orig);
struct address_space *mapping;
struct page *page;
if (!pfn_valid(pfn))
goto no_cache_flush;
page = pfn_to_page(pfn);
if (PageReserved(page))
goto no_cache_flush;
/* A real file page? */
mapping = page_mapping(page);
if (!mapping)
goto no_cache_flush;
paddr = (unsigned long) page_address(page);
if ((paddr ^ vaddr) & (1 << 13))
flush_dcache_page_all(mm, page);
}
no_cache_flush:
if (!fullmm)
tlb_batch_add_one(mm, vaddr, pte_exec(orig));
}
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
static void tlb_batch_pmd_scan(struct mm_struct *mm, unsigned long vaddr,
pmd_t pmd, bool exec)
{
unsigned long end;
pte_t *pte;
pte = pte_offset_map(&pmd, vaddr);
end = vaddr + HPAGE_SIZE;
while (vaddr < end) {
if (pte_val(*pte) & _PAGE_VALID)
tlb_batch_add_one(mm, vaddr, exec);
pte++;
vaddr += PAGE_SIZE;
}
pte_unmap(pte);
}
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
pmd_t orig = *pmdp;
*pmdp = pmd;
if (mm == &init_mm)
return;
if ((pmd_val(pmd) ^ pmd_val(orig)) & PMD_ISHUGE) {
if (pmd_val(pmd) & PMD_ISHUGE)
mm->context.huge_pte_count++;
else
mm->context.huge_pte_count--;
/* Do not try to allocate the TSB hash table if we
* don't have one already. We have various locks held
* and thus we'll end up doing a GFP_KERNEL allocation
* in an atomic context.
*
* Instead, we let the first TLB miss on a hugepage
* take care of this.
*/
}
if (!pmd_none(orig)) {
bool exec = ((pmd_val(orig) & PMD_HUGE_EXEC) != 0);
addr &= HPAGE_MASK;
if (pmd_val(orig) & PMD_ISHUGE)
tlb_batch_add_one(mm, addr, exec);
else
tlb_batch_pmd_scan(mm, addr, orig, exec);
}
}
void pgtable_trans_huge_deposit(struct mm_struct *mm, pgtable_t pgtable)
{
struct list_head *lh = (struct list_head *) pgtable;
assert_spin_locked(&mm->page_table_lock);
/* FIFO */
if (!mm->pmd_huge_pte)
INIT_LIST_HEAD(lh);
else
list_add(lh, (struct list_head *) mm->pmd_huge_pte);
mm->pmd_huge_pte = pgtable;
}
pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm)
{
struct list_head *lh;
pgtable_t pgtable;
assert_spin_locked(&mm->page_table_lock);
/* FIFO */
pgtable = mm->pmd_huge_pte;
lh = (struct list_head *) pgtable;
if (list_empty(lh))
mm->pmd_huge_pte = NULL;
else {
mm->pmd_huge_pte = (pgtable_t) lh->next;
list_del(lh);
}
pte_val(pgtable[0]) = 0;
pte_val(pgtable[1]) = 0;
return pgtable;
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
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