// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
*/
#include <linux/sched.h>
#include <linux/mm_types.h>
#include <linux/memblock.h>
#include <misc/cxl-base.h>
#include <asm/pgalloc.h>
#include <asm/tlb.h>
#include <asm/trace.h>
#include <asm/powernv.h>
#include <mm/mmu_decl.h>
#include <trace/events/thp.h>
unsigned long __pmd_frag_nr;
EXPORT_SYMBOL(__pmd_frag_nr);
unsigned long __pmd_frag_size_shift;
EXPORT_SYMBOL(__pmd_frag_size_shift);
int (*register_process_table)(unsigned long base, unsigned long page_size,
unsigned long tbl_size);
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
/*
* This is called when relaxing access to a hugepage. It's also called in the page
* fault path when we don't hit any of the major fault cases, ie, a minor
* update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
* handled those two for us, we additionally deal with missing execute
* permission here on some processors
*/
int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp, pmd_t entry, int dirty)
{
int changed;
#ifdef CONFIG_DEBUG_VM
WARN_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
assert_spin_locked(pmd_lockptr(vma->vm_mm, pmdp));
#endif
changed = !pmd_same(*(pmdp), entry);
if (changed) {
/*
* We can use MMU_PAGE_2M here, because only radix
* path look at the psize.
*/
__ptep_set_access_flags(vma, pmdp_ptep(pmdp),
pmd_pte(entry), address, MMU_PAGE_2M);
}
return changed;
}
int pmdp_test_and_clear_young(struct vm_area_struct *vma,
unsigned long address, pmd_t *pmdp)
{
return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
}
/*
* set a new huge pmd. We should not be called for updating
* an existing pmd entry. That should go via pmd_hugepage_update.
*/
void set_pmd_at(struct mm_struct *mm, unsigned long addr,
pmd_t *pmdp, pmd_t pmd)
{
#ifdef CONFIG_DEBUG_VM
/*
* Make sure hardware valid bit is not set. We don't do
* tlb flush for this update.
*/
WARN_ON(pte_hw_valid(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
assert_spin_locked(pmd_lockptr(mm, pmdp));
WARN_ON(!(pmd_large(pmd) || pmd_devmap(pmd)));
#endif
trace_hugepage_set_pmd(addr, pmd_val(pmd));
return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
}
static void do_nothing(void *unused)
{
}
/*
* Serialize against find_current_mm_pte which does lock-less
* lookup in page tables with local interrupts disabled. For huge pages
* it casts pmd_t to pte_t. Since format of pte_t is different from
* pmd_t we want to prevent transit from pmd pointing to page table
* to pmd pointing to huge page (and back) while interrupts are disabled.
* We clear pmd to possibly replace it with page table pointer in
* different code paths. So make sure we wait for the parallel
* find_current_mm_pte to finish.
*/
void serialize_against_pte_lookup(struct mm_struct *mm)
{
smp_mb();
smp_call_function_many(mm_cpumask(mm), do_nothing, NULL, 1);
}
/*
* We use this to invalidate a pmdp entry before switching from a
* hugepte to regular pmd entry.
*/
pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmdp)
{
unsigned long old_pmd;
old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID);
flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
/*
* This ensures that generic code that rely on IRQ disabling
* to prevent a parallel THP split work as expected.
*
* Marking the entry with _PAGE_INVALID && ~_PAGE_PRESENT requires
* a special case check in pmd_access_permitted.
*/
serialize_against_pte_lookup(vma->vm_mm);
return __pmd(old_pmd);
}
static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
{
return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
}
pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
{
unsigned long pmdv;
pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK;
return pmd_set_protbits(__pmd(pmdv), pgprot);
}
pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
{
return pfn_pmd(page_to_pfn(page), pgprot);
}
pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
{
unsigned long pmdv;
pmdv = pmd_val(pmd);
pmdv &= _HPAGE_CHG_MASK;
return pmd_set_protbits(__pmd(pmdv), newprot);
}
/*
* This is called at the end of handling a user page fault, when the
* fault has been handled by updating a HUGE PMD entry in the linux page tables.
* We use it to preload an HPTE into the hash table corresponding to
* the updated linux HUGE PMD entry.
*/
void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
pmd_t *pmd)
{
if (radix_enabled())
prefetch((void *)addr);
}
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
/* For use by kexec */
void mmu_cleanup_all(void)
{
if (radix_enabled())
radix__mmu_cleanup_all();
else if (mmu_hash_ops.hpte_clear_all)
mmu_hash_ops.hpte_clear_all();
}
#ifdef CONFIG_MEMORY_HOTPLUG
int __meminit create_section_mapping(unsigned long start, unsigned long end, int nid)
{
if (radix_enabled())
return radix__create_section_mapping(start, end, nid);
return hash__create_section_mapping(start, end, nid);
}
int __meminit remove_section_mapping(unsigned long start, unsigned long end)
{
if (radix_enabled())
return radix__remove_section_mapping(start, end);
return hash__remove_section_mapping(start, end);
}
#endif /* CONFIG_MEMORY_HOTPLUG */
void __init mmu_partition_table_init(void)
{
unsigned long patb_size = 1UL << PATB_SIZE_SHIFT;
unsigned long ptcr;
BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 36), "Partition table size too large.");
/* Initialize the Partition Table with no entries */
partition_tb = memblock_alloc(patb_size, patb_size);
if (!partition_tb)
panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
__func__, patb_size, patb_size);
/*
* update partition table control register,
* 64 K size.
*/
ptcr = __pa(partition_tb) | (PATB_SIZE_SHIFT - 12);
mtspr(SPRN_PTCR, ptcr);
powernv_set_nmmu_ptcr(ptcr);
}
void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
unsigned long dw1)
{
unsigned long old = be64_to_cpu(partition_tb[lpid].patb0);
partition_tb[lpid].patb0 = cpu_to_be64(dw0);
partition_tb[lpid].patb1 = cpu_to_be64(dw1);
/*
* Global flush of TLBs and partition table caches for this lpid.
* The type of flush (hash or radix) depends on what the previous
* use of this partition ID was, not the new use.
*/
asm volatile("ptesync" : : : "memory");
if (old & PATB_HR) {
asm volatile(PPC_TLBIE_5(%0,%1,2,0,1) : :
"r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
asm volatile(PPC_TLBIE_5(%0,%1,2,1,1) : :
"r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 1);
} else {
asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
"r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 0);
}
/* do we need fixup here ?*/
asm volatile("eieio; tlbsync; ptesync" : : : "memory");
}
EXPORT_SYMBOL_GPL(mmu_partition_table_set_entry);
static pmd_t *get_pmd_from_cache(struct mm_struct *mm)
{
void *pmd_frag, *ret;
if (PMD_FRAG_NR == 1)
return NULL;
spin_lock(&mm->page_table_lock);
ret = mm->context.pmd_frag;
if (ret) {
pmd_frag = ret + PMD_FRAG_SIZE;
/*
* If we have taken up all the fragments mark PTE page NULL
*/
if (((unsigned long)pmd_frag & ~PAGE_MASK) == 0)
pmd_frag = NULL;
mm->context.pmd_frag = pmd_frag;
}
spin_unlock(&mm->page_table_lock);
return (pmd_t *)ret;
}
static pmd_t *__alloc_for_pmdcache(struct mm_struct *mm)
{
void *ret = NULL;
struct page *page;
gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;
if (mm == &init_mm)
gfp &= ~__GFP_ACCOUNT;
page = alloc_page(gfp);
if (!page)
return NULL;
if (!pgtable_pmd_page_ctor(page)) {
__free_pages(page, 0);
return NULL;
}
atomic_set(&page->pt_frag_refcount, 1);
ret = page_address(page);
/*
* if we support only one fragment just return the
* allocated page.
*/
if (PMD_FRAG_NR == 1)
return ret;
spin_lock(&mm->page_table_lock);
/*
* If we find pgtable_page set, we return
* the allocated page with single fragement
* count.
*/
if (likely(!mm->context.pmd_frag)) {
atomic_set(&page->pt_frag_refcount, PMD_FRAG_NR);
mm->context.pmd_frag = ret + PMD_FRAG_SIZE;
}
spin_unlock(&mm->page_table_lock);
return (pmd_t *)ret;
}
pmd_t *pmd_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr)
{
pmd_t *pmd;
pmd = get_pmd_from_cache(mm);
if (pmd)
return pmd;
return __alloc_for_pmdcache(mm);
}
void pmd_fragment_free(unsigned long *pmd)
{
struct page *page = virt_to_page(pmd);
BUG_ON(atomic_read(&page->pt_frag_refcount) <= 0);
if (atomic_dec_and_test(&page->pt_frag_refcount)) {
pgtable_pmd_page_dtor(page);
__free_page(page);
}
}
static inline void pgtable_free(void *table, int index)
{
switch (index) {
case PTE_INDEX:
pte_fragment_free(table, 0);
break;
case PMD_INDEX:
pmd_fragment_free(table);
break;
case PUD_INDEX:
kmem_cache_free(PGT_CACHE(PUD_CACHE_INDEX), table);
break;
#if defined(CONFIG_PPC_4K_PAGES) && defined(CONFIG_HUGETLB_PAGE)
/* 16M hugepd directory at pud level */
case HTLB_16M_INDEX:
BUILD_BUG_ON(H_16M_CACHE_INDEX <= 0);
kmem_cache_free(PGT_CACHE(H_16M_CACHE_INDEX), table);
break;
/* 16G hugepd directory at the pgd level */
case HTLB_16G_INDEX:
BUILD_BUG_ON(H_16G_CACHE_INDEX <= 0);
kmem_cache_free(PGT_CACHE(H_16G_CACHE_INDEX), table);
break;
#endif
/* We don't free pgd table via RCU callback */
default:
BUG();
}
}
#ifdef CONFIG_SMP
void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index)
{
unsigned long pgf = (unsigned long)table;
BUG_ON(index > MAX_PGTABLE_INDEX_SIZE);
pgf |= index;
tlb_remove_table(tlb, (void *)pgf);
}
void __tlb_remove_table(void *_table)
{
void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
unsigned int index = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
return pgtable_free(table, index);
}
#else
void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index)
{
return pgtable_free(table, index);
}
#endif
#ifdef CONFIG_PROC_FS
atomic_long_t direct_pages_count[MMU_PAGE_COUNT];
void arch_report_meminfo(struct seq_file *m)
{
/*
* Hash maps the memory with one size mmu_linear_psize.
* So don't bother to print these on hash
*/
if (!radix_enabled())
return;
seq_printf(m, "DirectMap4k: %8lu kB\n",
atomic_long_read(&direct_pages_count[MMU_PAGE_4K]) << 2);
seq_printf(m, "DirectMap64k: %8lu kB\n",
atomic_long_read(&direct_pages_count[MMU_PAGE_64K]) << 6);
seq_printf(m, "DirectMap2M: %8lu kB\n",
atomic_long_read(&direct_pages_count[MMU_PAGE_2M]) << 11);
seq_printf(m, "DirectMap1G: %8lu kB\n",
atomic_long_read(&direct_pages_count[MMU_PAGE_1G]) << 20);
}
#endif /* CONFIG_PROC_FS */
pte_t ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr,
pte_t *ptep)
{
unsigned long pte_val;
/*
* Clear the _PAGE_PRESENT so that no hardware parallel update is
* possible. Also keep the pte_present true so that we don't take
* wrong fault.
*/
pte_val = pte_update(vma->vm_mm, addr, ptep, _PAGE_PRESENT, _PAGE_INVALID, 0);
return __pte(pte_val);
}
void ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr,
pte_t *ptep, pte_t old_pte, pte_t pte)
{
if (radix_enabled())
return radix__ptep_modify_prot_commit(vma, addr,
ptep, old_pte, pte);
set_pte_at(vma->vm_mm, addr, ptep, pte);
}
/*
* For hash translation mode, we use the deposited table to store hash slot
* information and they are stored at PTRS_PER_PMD offset from related pmd
* location. Hence a pmd move requires deposit and withdraw.
*
* For radix translation with split pmd ptl, we store the deposited table in the
* pmd page. Hence if we have different pmd page we need to withdraw during pmd
* move.
*
* With hash we use deposited table always irrespective of anon or not.
* With radix we use deposited table only for anonymous mapping.
*/
int pmd_move_must_withdraw(struct spinlock *new_pmd_ptl,
struct spinlock *old_pmd_ptl,
struct vm_area_struct *vma)
{
if (radix_enabled())
return (new_pmd_ptl != old_pmd_ptl) && vma_is_anonymous(vma);
return true;
}
