2 * Copyright 2015-2016, Aneesh Kumar K.V, IBM Corporation.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
10 #include <linux/sched.h>
11 #include <linux/mm_types.h>
12 #include <linux/memblock.h>
13 #include <misc/cxl-base.h>
15 #include <asm/pgalloc.h>
17 #include <asm/trace.h>
18 #include <asm/powernv.h>
21 #include <trace/events/thp.h>
23 unsigned long __pmd_frag_nr;
24 EXPORT_SYMBOL(__pmd_frag_nr);
25 unsigned long __pmd_frag_size_shift;
26 EXPORT_SYMBOL(__pmd_frag_size_shift);
28 int (*register_process_table)(unsigned long base, unsigned long page_size,
29 unsigned long tbl_size);
31 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
33 * This is called when relaxing access to a hugepage. It's also called in the page
34 * fault path when we don't hit any of the major fault cases, ie, a minor
35 * update of _PAGE_ACCESSED, _PAGE_DIRTY, etc... The generic code will have
36 * handled those two for us, we additionally deal with missing execute
37 * permission here on some processors
39 int pmdp_set_access_flags(struct vm_area_struct *vma, unsigned long address,
40 pmd_t *pmdp, pmd_t entry, int dirty)
43 #ifdef CONFIG_DEBUG_VM
44 WARN_ON(!pmd_trans_huge(*pmdp) && !pmd_devmap(*pmdp));
45 assert_spin_locked(pmd_lockptr(vma->vm_mm, pmdp));
47 changed = !pmd_same(*(pmdp), entry);
50 * We can use MMU_PAGE_2M here, because only radix
51 * path look at the psize.
53 __ptep_set_access_flags(vma, pmdp_ptep(pmdp),
54 pmd_pte(entry), address, MMU_PAGE_2M);
59 int pmdp_test_and_clear_young(struct vm_area_struct *vma,
60 unsigned long address, pmd_t *pmdp)
62 return __pmdp_test_and_clear_young(vma->vm_mm, address, pmdp);
65 * set a new huge pmd. We should not be called for updating
66 * an existing pmd entry. That should go via pmd_hugepage_update.
68 void set_pmd_at(struct mm_struct *mm, unsigned long addr,
69 pmd_t *pmdp, pmd_t pmd)
71 #ifdef CONFIG_DEBUG_VM
73 * Make sure hardware valid bit is not set. We don't do
74 * tlb flush for this update.
77 WARN_ON(pte_hw_valid(pmd_pte(*pmdp)) && !pte_protnone(pmd_pte(*pmdp)));
78 assert_spin_locked(pmd_lockptr(mm, pmdp));
79 WARN_ON(!(pmd_large(pmd) || pmd_devmap(pmd)));
81 trace_hugepage_set_pmd(addr, pmd_val(pmd));
82 return set_pte_at(mm, addr, pmdp_ptep(pmdp), pmd_pte(pmd));
85 static void do_nothing(void *unused)
90 * Serialize against find_current_mm_pte which does lock-less
91 * lookup in page tables with local interrupts disabled. For huge pages
92 * it casts pmd_t to pte_t. Since format of pte_t is different from
93 * pmd_t we want to prevent transit from pmd pointing to page table
94 * to pmd pointing to huge page (and back) while interrupts are disabled.
95 * We clear pmd to possibly replace it with page table pointer in
96 * different code paths. So make sure we wait for the parallel
97 * find_current_mm_pte to finish.
99 void serialize_against_pte_lookup(struct mm_struct *mm)
102 smp_call_function_many(mm_cpumask(mm), do_nothing, NULL, 1);
106 * We use this to invalidate a pmdp entry before switching from a
107 * hugepte to regular pmd entry.
109 pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
112 unsigned long old_pmd;
114 old_pmd = pmd_hugepage_update(vma->vm_mm, address, pmdp, _PAGE_PRESENT, _PAGE_INVALID);
115 flush_pmd_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
117 * This ensures that generic code that rely on IRQ disabling
118 * to prevent a parallel THP split work as expected.
120 serialize_against_pte_lookup(vma->vm_mm);
121 return __pmd(old_pmd);
124 static pmd_t pmd_set_protbits(pmd_t pmd, pgprot_t pgprot)
126 return __pmd(pmd_val(pmd) | pgprot_val(pgprot));
129 pmd_t pfn_pmd(unsigned long pfn, pgprot_t pgprot)
133 pmdv = (pfn << PAGE_SHIFT) & PTE_RPN_MASK;
134 return pmd_set_protbits(__pmd(pmdv), pgprot);
137 pmd_t mk_pmd(struct page *page, pgprot_t pgprot)
139 return pfn_pmd(page_to_pfn(page), pgprot);
142 pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
147 pmdv &= _HPAGE_CHG_MASK;
148 return pmd_set_protbits(__pmd(pmdv), newprot);
152 * This is called at the end of handling a user page fault, when the
153 * fault has been handled by updating a HUGE PMD entry in the linux page tables.
154 * We use it to preload an HPTE into the hash table corresponding to
155 * the updated linux HUGE PMD entry.
157 void update_mmu_cache_pmd(struct vm_area_struct *vma, unsigned long addr,
161 prefetch((void *)addr);
163 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
165 /* For use by kexec */
166 void mmu_cleanup_all(void)
169 radix__mmu_cleanup_all();
170 else if (mmu_hash_ops.hpte_clear_all)
171 mmu_hash_ops.hpte_clear_all();
174 #ifdef CONFIG_MEMORY_HOTPLUG
175 int __meminit create_section_mapping(unsigned long start, unsigned long end, int nid)
178 return radix__create_section_mapping(start, end, nid);
180 return hash__create_section_mapping(start, end, nid);
183 int __meminit remove_section_mapping(unsigned long start, unsigned long end)
186 return radix__remove_section_mapping(start, end);
188 return hash__remove_section_mapping(start, end);
190 #endif /* CONFIG_MEMORY_HOTPLUG */
192 void __init mmu_partition_table_init(void)
194 unsigned long patb_size = 1UL << PATB_SIZE_SHIFT;
197 BUILD_BUG_ON_MSG((PATB_SIZE_SHIFT > 36), "Partition table size too large.");
198 partition_tb = __va(memblock_alloc_base(patb_size, patb_size,
199 MEMBLOCK_ALLOC_ANYWHERE));
201 /* Initialize the Partition Table with no entries */
202 memset((void *)partition_tb, 0, patb_size);
205 * update partition table control register,
208 ptcr = __pa(partition_tb) | (PATB_SIZE_SHIFT - 12);
209 mtspr(SPRN_PTCR, ptcr);
210 powernv_set_nmmu_ptcr(ptcr);
213 void mmu_partition_table_set_entry(unsigned int lpid, unsigned long dw0,
216 unsigned long old = be64_to_cpu(partition_tb[lpid].patb0);
218 partition_tb[lpid].patb0 = cpu_to_be64(dw0);
219 partition_tb[lpid].patb1 = cpu_to_be64(dw1);
222 * Global flush of TLBs and partition table caches for this lpid.
223 * The type of flush (hash or radix) depends on what the previous
224 * use of this partition ID was, not the new use.
226 asm volatile("ptesync" : : : "memory");
228 asm volatile(PPC_TLBIE_5(%0,%1,2,0,1) : :
229 "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
230 asm volatile(PPC_TLBIE_5(%0,%1,2,1,1) : :
231 "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
232 trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 1);
234 asm volatile(PPC_TLBIE_5(%0,%1,2,0,0) : :
235 "r" (TLBIEL_INVAL_SET_LPID), "r" (lpid));
236 trace_tlbie(lpid, 0, TLBIEL_INVAL_SET_LPID, lpid, 2, 0, 0);
238 /* do we need fixup here ?*/
239 asm volatile("eieio; tlbsync; ptesync" : : : "memory");
241 EXPORT_SYMBOL_GPL(mmu_partition_table_set_entry);
243 static pmd_t *get_pmd_from_cache(struct mm_struct *mm)
245 void *pmd_frag, *ret;
247 if (PMD_FRAG_NR == 1)
250 spin_lock(&mm->page_table_lock);
251 ret = mm->context.pmd_frag;
253 pmd_frag = ret + PMD_FRAG_SIZE;
255 * If we have taken up all the fragments mark PTE page NULL
257 if (((unsigned long)pmd_frag & ~PAGE_MASK) == 0)
259 mm->context.pmd_frag = pmd_frag;
261 spin_unlock(&mm->page_table_lock);
265 static pmd_t *__alloc_for_pmdcache(struct mm_struct *mm)
269 gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;
272 gfp &= ~__GFP_ACCOUNT;
273 page = alloc_page(gfp);
276 if (!pgtable_pmd_page_ctor(page)) {
277 __free_pages(page, 0);
281 atomic_set(&page->pt_frag_refcount, 1);
283 ret = page_address(page);
285 * if we support only one fragment just return the
288 if (PMD_FRAG_NR == 1)
291 spin_lock(&mm->page_table_lock);
293 * If we find pgtable_page set, we return
294 * the allocated page with single fragement
297 if (likely(!mm->context.pmd_frag)) {
298 atomic_set(&page->pt_frag_refcount, PMD_FRAG_NR);
299 mm->context.pmd_frag = ret + PMD_FRAG_SIZE;
301 spin_unlock(&mm->page_table_lock);
306 pmd_t *pmd_fragment_alloc(struct mm_struct *mm, unsigned long vmaddr)
310 pmd = get_pmd_from_cache(mm);
314 return __alloc_for_pmdcache(mm);
317 void pmd_fragment_free(unsigned long *pmd)
319 struct page *page = virt_to_page(pmd);
321 BUG_ON(atomic_read(&page->pt_frag_refcount) <= 0);
322 if (atomic_dec_and_test(&page->pt_frag_refcount)) {
323 pgtable_pmd_page_dtor(page);
328 static inline void pgtable_free(void *table, int index)
332 pte_fragment_free(table, 0);
335 pmd_fragment_free(table);
338 kmem_cache_free(PGT_CACHE(PUD_CACHE_INDEX), table);
340 #if defined(CONFIG_PPC_4K_PAGES) && defined(CONFIG_HUGETLB_PAGE)
341 /* 16M hugepd directory at pud level */
343 BUILD_BUG_ON(H_16M_CACHE_INDEX <= 0);
344 kmem_cache_free(PGT_CACHE(H_16M_CACHE_INDEX), table);
346 /* 16G hugepd directory at the pgd level */
348 BUILD_BUG_ON(H_16G_CACHE_INDEX <= 0);
349 kmem_cache_free(PGT_CACHE(H_16G_CACHE_INDEX), table);
352 /* We don't free pgd table via RCU callback */
359 void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index)
361 unsigned long pgf = (unsigned long)table;
363 BUG_ON(index > MAX_PGTABLE_INDEX_SIZE);
365 tlb_remove_table(tlb, (void *)pgf);
368 void __tlb_remove_table(void *_table)
370 void *table = (void *)((unsigned long)_table & ~MAX_PGTABLE_INDEX_SIZE);
371 unsigned int index = (unsigned long)_table & MAX_PGTABLE_INDEX_SIZE;
373 return pgtable_free(table, index);
376 void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int index)
378 return pgtable_free(table, index);
382 #ifdef CONFIG_PROC_FS
383 atomic_long_t direct_pages_count[MMU_PAGE_COUNT];
385 void arch_report_meminfo(struct seq_file *m)
388 * Hash maps the memory with one size mmu_linear_psize.
389 * So don't bother to print these on hash
391 if (!radix_enabled())
393 seq_printf(m, "DirectMap4k: %8lu kB\n",
394 atomic_long_read(&direct_pages_count[MMU_PAGE_4K]) << 2);
395 seq_printf(m, "DirectMap64k: %8lu kB\n",
396 atomic_long_read(&direct_pages_count[MMU_PAGE_64K]) << 6);
397 seq_printf(m, "DirectMap2M: %8lu kB\n",
398 atomic_long_read(&direct_pages_count[MMU_PAGE_2M]) << 11);
399 seq_printf(m, "DirectMap1G: %8lu kB\n",
400 atomic_long_read(&direct_pages_count[MMU_PAGE_1G]) << 20);
402 #endif /* CONFIG_PROC_FS */