arch/ppc64/kernel/iSeries_htab.c

   1 /*
   2  * iSeries hashtable management.
   3  *      Derived from pSeries_htab.c
   4  *
   5  * SMP scalability work:
   6  *    Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License
  10  * as published by the Free Software Foundation; either version
  11  * 2 of the License, or (at your option) any later version.
  12  */
  13 #include <asm/machdep.h>
  14 #include <asm/pgtable.h>
  15 #include <asm/mmu.h>
  16 #include <asm/mmu_context.h>
  17 #include <asm/iSeries/HvCallHpt.h>
  18 #include <asm/abs_addr.h>
  19 #include <linux/spinlock.h>
  20
  21 static spinlock_t iSeries_hlocks[64] __cacheline_aligned_in_smp = { [0 ... 63] = SPIN_LOCK_UNLOCKED};
  22
  23 /*
  24  * Very primitive algorithm for picking up a lock
  25  */
  26 static inline void iSeries_hlock(unsigned long slot)
  27 {
  28         if (slot & 0x8)
  29                 slot = ~slot;
  30         spin_lock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
  31 }
  32
  33 static inline void iSeries_hunlock(unsigned long slot)
  34 {
  35         if (slot & 0x8)
  36                 slot = ~slot;
  37         spin_unlock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
  38 }
  39
  40 static long iSeries_hpte_insert(unsigned long hpte_group, unsigned long va,
  41                                 unsigned long prpn, unsigned long vflags,
  42                                 unsigned long rflags)
  43 {
  44         long slot;
  45         hpte_t lhpte;
  46         int secondary = 0;
  47
  48         /*
  49          * The hypervisor tries both primary and secondary.
  50          * If we are being called to insert in the secondary,
  51          * it means we have already tried both primary and secondary,
  52          * so we return failure immediately.
  53          */
  54         if (vflags & HPTE_V_SECONDARY)
  55                 return -1;
  56
  57         iSeries_hlock(hpte_group);
  58
  59         slot = HvCallHpt_findValid(&lhpte, va >> PAGE_SHIFT);
  60         BUG_ON(lhpte.v & HPTE_V_VALID);
  61
  62         if (slot == -1) { /* No available entry found in either group */
  63                 iSeries_hunlock(hpte_group);
  64                 return -1;
  65         }
  66
  67         if (slot < 0) {         /* MSB set means secondary group */
  68                 vflags |= HPTE_V_VALID;
  69                 secondary = 1;
  70                 slot &= 0x7fffffffffffffff;
  71         }
  72
  73         lhpte.v = (va >> 23) << HPTE_V_AVPN_SHIFT | vflags | HPTE_V_VALID;
  74         lhpte.r = (physRpn_to_absRpn(prpn) << HPTE_R_RPN_SHIFT) | rflags;
  75
  76         /* Now fill in the actual HPTE */
  77         HvCallHpt_addValidate(slot, secondary, &lhpte);
  78
  79         iSeries_hunlock(hpte_group);
  80
  81         return (secondary << 3) | (slot & 7);
  82 }
  83
  84 static unsigned long iSeries_hpte_getword0(unsigned long slot)
  85 {
  86         hpte_t hpte;
  87
  88         HvCallHpt_get(&hpte, slot);
  89         return hpte.v;
  90 }
  91
  92 static long iSeries_hpte_remove(unsigned long hpte_group)
  93 {
  94         unsigned long slot_offset;
  95         int i;
  96         unsigned long hpte_v;
  97
  98         /* Pick a random slot to start at */
  99         slot_offset = mftb() & 0x7;
 100
 101         iSeries_hlock(hpte_group);
 102
 103         for (i = 0; i < HPTES_PER_GROUP; i++) {
 104                 hpte_v = iSeries_hpte_getword0(hpte_group + slot_offset);
 105
 106                 if (! (hpte_v & HPTE_V_BOLTED)) {
 107                         HvCallHpt_invalidateSetSwBitsGet(hpte_group +
 108                                                          slot_offset, 0, 0);
 109                         iSeries_hunlock(hpte_group);
 110                         return i;
 111                 }
 112
 113                 slot_offset++;
 114                 slot_offset &= 0x7;
 115         }
 116
 117         iSeries_hunlock(hpte_group);
 118
 119         return -1;
 120 }
 121
 122 /*
 123  * The HyperVisor expects the "flags" argument in this form:
 124  *      bits  0..59 : reserved
 125  *      bit      60 : N
 126  *      bits 61..63 : PP2,PP1,PP0
 127  */
 128 static long iSeries_hpte_updatepp(unsigned long slot, unsigned long newpp,
 129                                   unsigned long va, int large, int local)
 130 {
 131         hpte_t hpte;
 132         unsigned long avpn = va >> 23;
 133
 134         iSeries_hlock(slot);
 135
 136         HvCallHpt_get(&hpte, slot);
 137         if ((HPTE_V_AVPN_VAL(hpte.v) == avpn) && (hpte.v & HPTE_V_VALID)) {
 138                 /*
 139                  * Hypervisor expects bits as NPPP, which is
 140                  * different from how they are mapped in our PP.
 141                  */
 142                 HvCallHpt_setPp(slot, (newpp & 0x3) | ((newpp & 0x4) << 1));
 143                 iSeries_hunlock(slot);
 144                 return 0;
 145         }
 146         iSeries_hunlock(slot);
 147
 148         return -1;
 149 }
 150
 151 /*
 152  * Functions used to find the PTE for a particular virtual address.
 153  * Only used during boot when bolting pages.
 154  *
 155  * Input : vpn      : virtual page number
 156  * Output: PTE index within the page table of the entry
 157  *         -1 on failure
 158  */
 159 static long iSeries_hpte_find(unsigned long vpn)
 160 {
 161         hpte_t hpte;
 162         long slot;
 163
 164         /*
 165          * The HvCallHpt_findValid interface is as follows:
 166          * 0xffffffffffffffff : No entry found.
 167          * 0x00000000xxxxxxxx : Entry found in primary group, slot x
 168          * 0x80000000xxxxxxxx : Entry found in secondary group, slot x
 169          */
 170         slot = HvCallHpt_findValid(&hpte, vpn);
 171         if (hpte.v & HPTE_V_VALID) {
 172                 if (slot < 0) {
 173                         slot &= 0x7fffffffffffffff;
 174                         slot = -slot;
 175                 }
 176         } else
 177                 slot = -1;
 178         return slot;
 179 }
 180
 181 /*
 182  * Update the page protection bits. Intended to be used to create
 183  * guard pages for kernel data structures on pages which are bolted
 184  * in the HPT. Assumes pages being operated on will not be stolen.
 185  * Does not work on large pages.
 186  *
 187  * No need to lock here because we should be the only user.
 188  */
 189 static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea)
 190 {
 191         unsigned long vsid,va,vpn;
 192         long slot;
 193
 194         vsid = get_kernel_vsid(ea);
 195         va = (vsid << 28) | (ea & 0x0fffffff);
 196         vpn = va >> PAGE_SHIFT;
 197         slot = iSeries_hpte_find(vpn);
 198         if (slot == -1)
 199                 panic("updateboltedpp: Could not find page to bolt\n");
 200         HvCallHpt_setPp(slot, newpp);
 201 }
 202
 203 static void iSeries_hpte_invalidate(unsigned long slot, unsigned long va,
 204                                     int large, int local)
 205 {
 206         unsigned long hpte_v;
 207         unsigned long avpn = va >> 23;
 208         unsigned long flags;
 209
 210         local_irq_save(flags);
 211
 212         iSeries_hlock(slot);
 213
 214         hpte_v = iSeries_hpte_getword0(slot);
 215
 216         if ((HPTE_V_AVPN_VAL(hpte_v) == avpn) && (hpte_v & HPTE_V_VALID))
 217                 HvCallHpt_invalidateSetSwBitsGet(slot, 0, 0);
 218
 219         iSeries_hunlock(slot);
 220
 221         local_irq_restore(flags);
 222 }
 223
 224 void hpte_init_iSeries(void)
 225 {
 226         ppc_md.hpte_invalidate  = iSeries_hpte_invalidate;
 227         ppc_md.hpte_updatepp    = iSeries_hpte_updatepp;
 228         ppc_md.hpte_updateboltedpp = iSeries_hpte_updateboltedpp;
 229         ppc_md.hpte_insert      = iSeries_hpte_insert;
 230         ppc_md.hpte_remove      = iSeries_hpte_remove;
 231
 232         htab_finish_init();
 233 }