arch/powerpc/mm/hugetlbpage-book3e.c

   1 /*
   2  * PPC Huge TLB Page Support for Book3E MMU
   3  *
   4  * Copyright (C) 2009 David Gibson, IBM Corporation.
   5  * Copyright (C) 2011 Becky Bruce, Freescale Semiconductor
   6  *
   7  */
   8 #include <linux/mm.h>
   9 #include <linux/hugetlb.h>
  10
  11 static inline int mmu_get_tsize(int psize)
  12 {
  13         return mmu_psize_defs[psize].enc;
  14 }
  15
  16 static inline int book3e_tlb_exists(unsigned long ea, unsigned long pid)
  17 {
  18         int found = 0;
  19
  20         mtspr(SPRN_MAS6, pid << 16);
  21         if (mmu_has_feature(MMU_FTR_USE_TLBRSRV)) {
  22                 asm volatile(
  23                         "li     %0,0\n"
  24                         "tlbsx. 0,%1\n"
  25                         "bne    1f\n"
  26                         "li     %0,1\n"
  27                         "1:\n"
  28                         : "=&r"(found) : "r"(ea));
  29         } else {
  30                 asm volatile(
  31                         "tlbsx  0,%1\n"
  32                         "mfspr  %0,0x271\n"
  33                         "srwi   %0,%0,31\n"
  34                         : "=&r"(found) : "r"(ea));
  35         }
  36
  37         return found;
  38 }
  39
  40 void book3e_hugetlb_preload(struct vm_area_struct *vma, unsigned long ea,
  41                             pte_t pte)
  42 {
  43         unsigned long mas1, mas2;
  44         u64 mas7_3;
  45         unsigned long psize, tsize, shift;
  46         unsigned long flags;
  47         struct mm_struct *mm;
  48
  49 #ifdef CONFIG_PPC_FSL_BOOK3E
  50         int index, ncams;
  51 #endif
  52
  53         if (unlikely(is_kernel_addr(ea)))
  54                 return;
  55
  56         mm = vma->vm_mm;
  57
  58 #ifdef CONFIG_PPC_MM_SLICES
  59         psize = get_slice_psize(mm, ea);
  60         tsize = mmu_get_tsize(psize);
  61         shift = mmu_psize_defs[psize].shift;
  62 #else
  63         psize = vma_mmu_pagesize(vma);
  64         shift = __ilog2(psize);
  65         tsize = shift - 10;
  66 #endif
  67
  68         /*
  69          * We can't be interrupted while we're setting up the MAS
  70          * regusters or after we've confirmed that no tlb exists.
  71          */
  72         local_irq_save(flags);
  73
  74         if (unlikely(book3e_tlb_exists(ea, mm->context.id))) {
  75                 local_irq_restore(flags);
  76                 return;
  77         }
  78
  79 #ifdef CONFIG_PPC_FSL_BOOK3E
  80         ncams = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
  81
  82         /* We have to use the CAM(TLB1) on FSL parts for hugepages */
  83         index = __get_cpu_var(next_tlbcam_idx);
  84         mtspr(SPRN_MAS0, MAS0_ESEL(index) | MAS0_TLBSEL(1));
  85
  86         /* Just round-robin the entries and wrap when we hit the end */
  87         if (unlikely(index == ncams - 1))
  88                 __get_cpu_var(next_tlbcam_idx) = tlbcam_index;
  89         else
  90                 __get_cpu_var(next_tlbcam_idx)++;
  91 #endif
  92         mas1 = MAS1_VALID | MAS1_TID(mm->context.id) | MAS1_TSIZE(tsize);
  93         mas2 = ea & ~((1UL << shift) - 1);
  94         mas2 |= (pte_val(pte) >> PTE_WIMGE_SHIFT) & MAS2_WIMGE_MASK;
  95         mas7_3 = (u64)pte_pfn(pte) << PAGE_SHIFT;
  96         mas7_3 |= (pte_val(pte) >> PTE_BAP_SHIFT) & MAS3_BAP_MASK;
  97         if (!pte_dirty(pte))
  98                 mas7_3 &= ~(MAS3_SW|MAS3_UW);
  99
 100         mtspr(SPRN_MAS1, mas1);
 101         mtspr(SPRN_MAS2, mas2);
 102
 103         if (mmu_has_feature(MMU_FTR_USE_PAIRED_MAS)) {
 104                 mtspr(SPRN_MAS7_MAS3, mas7_3);
 105         } else {
 106                 mtspr(SPRN_MAS7, upper_32_bits(mas7_3));
 107                 mtspr(SPRN_MAS3, lower_32_bits(mas7_3));
 108         }
 109
 110         asm volatile ("tlbwe");
 111
 112         local_irq_restore(flags);
 113 }
 114
 115 void flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
 116 {
 117         struct hstate *hstate = hstate_file(vma->vm_file);
 118         unsigned long tsize = huge_page_shift(hstate) - 10;
 119
 120         __flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr, tsize, 0);
 121
 122 }