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         unsigned long arpn;
  45         long slot;
  46         hpte_t lhpte;
  47         int secondary = 0;
  48
  49         /*
  50          * The hypervisor tries both primary and secondary.
  51          * If we are being called to insert in the secondary,
  52          * it means we have already tried both primary and secondary,
  53          * so we return failure immediately.
  54          */
  55         if (vflags & HPTE_V_SECONDARY)
  56                 return -1;
  57
  58         iSeries_hlock(hpte_group);
  59
  60         slot = HvCallHpt_findValid(&lhpte, va >> PAGE_SHIFT);
  61         BUG_ON(lhpte.v & HPTE_V_VALID);
  62
  63         if (slot == -1) { /* No available entry found in either group */
  64                 iSeries_hunlock(hpte_group);
  65                 return -1;
  66         }
  67
  68         if (slot < 0) {         /* MSB set means secondary group */
  69                 vflags |= HPTE_V_VALID;
  70                 secondary = 1;
  71                 slot &= 0x7fffffffffffffff;
  72         }
  73
  74         arpn = phys_to_abs(prpn << PAGE_SHIFT) >> PAGE_SHIFT;
  75
  76         lhpte.v = (va >> 23) << HPTE_V_AVPN_SHIFT | vflags | HPTE_V_VALID;
  77         lhpte.r = (arpn << HPTE_R_RPN_SHIFT) | rflags;
  78
  79         /* Now fill in the actual HPTE */
  80         HvCallHpt_addValidate(slot, secondary, &lhpte);
  81
  82         iSeries_hunlock(hpte_group);
  83
  84         return (secondary << 3) | (slot & 7);
  85 }
  86
  87 static unsigned long iSeries_hpte_getword0(unsigned long slot)
  88 {
  89         hpte_t hpte;
  90
  91         HvCallHpt_get(&hpte, slot);
  92         return hpte.v;
  93 }
  94
  95 static long iSeries_hpte_remove(unsigned long hpte_group)
  96 {
  97         unsigned long slot_offset;
  98         int i;
  99         unsigned long hpte_v;
 100
 101         /* Pick a random slot to start at */
 102         slot_offset = mftb() & 0x7;
 103
 104         iSeries_hlock(hpte_group);
 105
 106         for (i = 0; i < HPTES_PER_GROUP; i++) {
 107                 hpte_v = iSeries_hpte_getword0(hpte_group + slot_offset);
 108
 109                 if (! (hpte_v & HPTE_V_BOLTED)) {
 110                         HvCallHpt_invalidateSetSwBitsGet(hpte_group +
 111                                                          slot_offset, 0, 0);
 112                         iSeries_hunlock(hpte_group);
 113                         return i;
 114                 }
 115
 116                 slot_offset++;
 117                 slot_offset &= 0x7;
 118         }
 119
 120         iSeries_hunlock(hpte_group);
 121
 122         return -1;
 123 }
 124
 125 /*
 126  * The HyperVisor expects the "flags" argument in this form:
 127  *      bits  0..59 : reserved
 128  *      bit      60 : N
 129  *      bits 61..63 : PP2,PP1,PP0
 130  */
 131 static long iSeries_hpte_updatepp(unsigned long slot, unsigned long newpp,
 132                                   unsigned long va, int large, int local)
 133 {
 134         hpte_t hpte;
 135         unsigned long avpn = va >> 23;
 136
 137         iSeries_hlock(slot);
 138
 139         HvCallHpt_get(&hpte, slot);
 140         if ((HPTE_V_AVPN_VAL(hpte.v) == avpn) && (hpte.v & HPTE_V_VALID)) {
 141                 /*
 142                  * Hypervisor expects bits as NPPP, which is
 143                  * different from how they are mapped in our PP.
 144                  */
 145                 HvCallHpt_setPp(slot, (newpp & 0x3) | ((newpp & 0x4) << 1));
 146                 iSeries_hunlock(slot);
 147                 return 0;
 148         }
 149         iSeries_hunlock(slot);
 150
 151         return -1;
 152 }
 153
 154 /*
 155  * Functions used to find the PTE for a particular virtual address.
 156  * Only used during boot when bolting pages.
 157  *
 158  * Input : vpn      : virtual page number
 159  * Output: PTE index within the page table of the entry
 160  *         -1 on failure
 161  */
 162 static long iSeries_hpte_find(unsigned long vpn)
 163 {
 164         hpte_t hpte;
 165         long slot;
 166
 167         /*
 168          * The HvCallHpt_findValid interface is as follows:
 169          * 0xffffffffffffffff : No entry found.
 170          * 0x00000000xxxxxxxx : Entry found in primary group, slot x
 171          * 0x80000000xxxxxxxx : Entry found in secondary group, slot x
 172          */
 173         slot = HvCallHpt_findValid(&hpte, vpn);
 174         if (hpte.v & HPTE_V_VALID) {
 175                 if (slot < 0) {
 176                         slot &= 0x7fffffffffffffff;
 177                         slot = -slot;
 178                 }
 179         } else
 180                 slot = -1;
 181         return slot;
 182 }
 183
 184 /*
 185  * Update the page protection bits. Intended to be used to create
 186  * guard pages for kernel data structures on pages which are bolted
 187  * in the HPT. Assumes pages being operated on will not be stolen.
 188  * Does not work on large pages.
 189  *
 190  * No need to lock here because we should be the only user.
 191  */
 192 static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea)
 193 {
 194         unsigned long vsid,va,vpn;
 195         long slot;
 196
 197         vsid = get_kernel_vsid(ea);
 198         va = (vsid << 28) | (ea & 0x0fffffff);
 199         vpn = va >> PAGE_SHIFT;
 200         slot = iSeries_hpte_find(vpn);
 201         if (slot == -1)
 202                 panic("updateboltedpp: Could not find page to bolt\n");
 203         HvCallHpt_setPp(slot, newpp);
 204 }
 205
 206 static void iSeries_hpte_invalidate(unsigned long slot, unsigned long va,
 207                                     int large, int local)
 208 {
 209         unsigned long hpte_v;
 210         unsigned long avpn = va >> 23;
 211         unsigned long flags;
 212
 213         local_irq_save(flags);
 214
 215         iSeries_hlock(slot);
 216
 217         hpte_v = iSeries_hpte_getword0(slot);
 218
 219         if ((HPTE_V_AVPN_VAL(hpte_v) == avpn) && (hpte_v & HPTE_V_VALID))
 220                 HvCallHpt_invalidateSetSwBitsGet(slot, 0, 0);
 221
 222         iSeries_hunlock(slot);
 223
 224         local_irq_restore(flags);
 225 }
 226
 227 void hpte_init_iSeries(void)
 228 {
 229         ppc_md.hpte_invalidate  = iSeries_hpte_invalidate;
 230         ppc_md.hpte_updatepp    = iSeries_hpte_updatepp;
 231         ppc_md.hpte_updateboltedpp = iSeries_hpte_updateboltedpp;
 232         ppc_md.hpte_insert      = iSeries_hpte_insert;
 233         ppc_md.hpte_remove      = iSeries_hpte_remove;
 234
 235         htab_finish_init();
 236 }