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 mm_struct *mm, unsigned long ea, pte_t pte)
  41 {
  42         unsigned long mas1, mas2;
  43         u64 mas7_3;
  44         unsigned long psize, tsize, shift;
  45         unsigned long flags;
  46
  47 #ifdef CONFIG_PPC_FSL_BOOK3E
  48         int index, lz, ncams;
  49         struct vm_area_struct *vma;
  50 #endif
  51
  52         if (unlikely(is_kernel_addr(ea)))
  53                 return;
  54
  55 #ifdef CONFIG_MM_SLICES
  56         psize = mmu_get_tsize(get_slice_psize(mm, ea));
  57         tsize = mmu_get_psize(psize);
  58         shift = mmu_psize_defs[psize].shift;
  59 #else
  60         vma = find_vma(mm, ea);
  61         psize = vma_mmu_pagesize(vma);  /* returns actual size in bytes */
  62         asm (PPC_CNTLZL "%0,%1" : "=r" (lz) : "r" (psize));
  63         shift = 31 - lz;
  64         tsize = 21 - lz;
  65 #endif
  66
  67         /*
  68          * We can't be interrupted while we're setting up the MAS
  69          * regusters or after we've confirmed that no tlb exists.
  70          */
  71         local_irq_save(flags);
  72
  73         if (unlikely(book3e_tlb_exists(ea, mm->context.id))) {
  74                 local_irq_restore(flags);
  75                 return;
  76         }
  77
  78 #ifdef CONFIG_PPC_FSL_BOOK3E
  79         ncams = mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY;
  80
  81         /* We have to use the CAM(TLB1) on FSL parts for hugepages */
  82         index = __get_cpu_var(next_tlbcam_idx);
  83         mtspr(SPRN_MAS0, MAS0_ESEL(index) | MAS0_TLBSEL(1));
  84
  85         /* Just round-robin the entries and wrap when we hit the end */
  86         if (unlikely(index == ncams - 1))
  87                 __get_cpu_var(next_tlbcam_idx) = tlbcam_index;
  88         else
  89                 __get_cpu_var(next_tlbcam_idx)++;
  90 #endif
  91         mas1 = MAS1_VALID | MAS1_TID(mm->context.id) | MAS1_TSIZE(tsize);
  92         mas2 = ea & ~((1UL << shift) - 1);
  93         mas2 |= (pte_val(pte) >> PTE_WIMGE_SHIFT) & MAS2_WIMGE_MASK;
  94         mas7_3 = (u64)pte_pfn(pte) << PAGE_SHIFT;
  95         mas7_3 |= (pte_val(pte) >> PTE_BAP_SHIFT) & MAS3_BAP_MASK;
  96         if (!pte_dirty(pte))
  97                 mas7_3 &= ~(MAS3_SW|MAS3_UW);
  98
  99         mtspr(SPRN_MAS1, mas1);
 100         mtspr(SPRN_MAS2, mas2);
 101
 102         if (mmu_has_feature(MMU_FTR_USE_PAIRED_MAS)) {
 103                 mtspr(SPRN_MAS7_MAS3, mas7_3);
 104         } else {
 105                 mtspr(SPRN_MAS7, upper_32_bits(mas7_3));
 106                 mtspr(SPRN_MAS3, lower_32_bits(mas7_3));
 107         }
 108
 109         asm volatile ("tlbwe");
 110
 111         local_irq_restore(flags);
 112 }
 113
 114 void flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
 115 {
 116         struct hstate *hstate = hstate_file(vma->vm_file);
 117         unsigned long tsize = huge_page_shift(hstate) - 10;
 118
 119         __flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr, tsize, 0);
 120
 121 }