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, int secondary,
  42                          unsigned long hpteflags, int bolted, int large)
  43 {
  44         long slot;
  45         HPTE lhpte;
  46
  47         /*
  48          * The hypervisor tries both primary and secondary.
  49          * If we are being called to insert in the secondary,
  50          * it means we have already tried both primary and secondary,
  51          * so we return failure immediately.
  52          */
  53         if (secondary)
  54                 return -1;
  55
  56         iSeries_hlock(hpte_group);
  57
  58         slot = HvCallHpt_findValid(&lhpte, va >> PAGE_SHIFT);
  59         BUG_ON(lhpte.dw0.dw0.v);
  60
  61         if (slot == -1) { /* No available entry found in either group */
  62                 iSeries_hunlock(hpte_group);
  63                 return -1;
  64         }
  65
  66         if (slot < 0) {         /* MSB set means secondary group */
  67                 secondary = 1;
  68                 slot &= 0x7fffffffffffffff;
  69         }
  70
  71         lhpte.dw1.dword1      = 0;
  72         lhpte.dw1.dw1.rpn     = physRpn_to_absRpn(prpn);
  73         lhpte.dw1.flags.flags = hpteflags;
  74
  75         lhpte.dw0.dword0      = 0;
  76         lhpte.dw0.dw0.avpn    = va >> 23;
  77         lhpte.dw0.dw0.h       = secondary;
  78         lhpte.dw0.dw0.bolted  = bolted;
  79         lhpte.dw0.dw0.v       = 1;
  80
  81         /* Now fill in the actual HPTE */
  82         HvCallHpt_addValidate(slot, secondary, &lhpte);
  83
  84         iSeries_hunlock(hpte_group);
  85
  86         return (secondary << 3) | (slot & 7);
  87 }
  88
  89 static unsigned long iSeries_hpte_getword0(unsigned long slot)
  90 {
  91         unsigned long dword0;
  92         HPTE hpte;
  93
  94         HvCallHpt_get(&hpte, slot);
  95         dword0 = hpte.dw0.dword0;
  96
  97         return dword0;
  98 }
  99
 100 static long iSeries_hpte_remove(unsigned long hpte_group)
 101 {
 102         unsigned long slot_offset;
 103         int i;
 104         HPTE lhpte;
 105
 106         /* Pick a random slot to start at */
 107         slot_offset = mftb() & 0x7;
 108
 109         iSeries_hlock(hpte_group);
 110
 111         for (i = 0; i < HPTES_PER_GROUP; i++) {
 112                 lhpte.dw0.dword0 =
 113                         iSeries_hpte_getword0(hpte_group + slot_offset);
 114
 115                 if (!lhpte.dw0.dw0.bolted) {
 116                         HvCallHpt_invalidateSetSwBitsGet(hpte_group +
 117                                                          slot_offset, 0, 0);
 118                         iSeries_hunlock(hpte_group);
 119                         return i;
 120                 }
 121
 122                 slot_offset++;
 123                 slot_offset &= 0x7;
 124         }
 125
 126         iSeries_hunlock(hpte_group);
 127
 128         return -1;
 129 }
 130
 131 /*
 132  * The HyperVisor expects the "flags" argument in this form:
 133  *      bits  0..59 : reserved
 134  *      bit      60 : N
 135  *      bits 61..63 : PP2,PP1,PP0
 136  */
 137 static long iSeries_hpte_updatepp(unsigned long slot, unsigned long newpp,
 138                                   unsigned long va, int large, int local)
 139 {
 140         HPTE hpte;
 141         unsigned long avpn = va >> 23;
 142
 143         iSeries_hlock(slot);
 144
 145         HvCallHpt_get(&hpte, slot);
 146         if ((hpte.dw0.dw0.avpn == avpn) && (hpte.dw0.dw0.v)) {
 147                 /*
 148                  * Hypervisor expects bits as NPPP, which is
 149                  * different from how they are mapped in our PP.
 150                  */
 151                 HvCallHpt_setPp(slot, (newpp & 0x3) | ((newpp & 0x4) << 1));
 152                 iSeries_hunlock(slot);
 153                 return 0;
 154         }
 155         iSeries_hunlock(slot);
 156
 157         return -1;
 158 }
 159
 160 /*
 161  * Functions used to find the PTE for a particular virtual address.
 162  * Only used during boot when bolting pages.
 163  *
 164  * Input : vpn      : virtual page number
 165  * Output: PTE index within the page table of the entry
 166  *         -1 on failure
 167  */
 168 static long iSeries_hpte_find(unsigned long vpn)
 169 {
 170         HPTE hpte;
 171         long slot;
 172
 173         /*
 174          * The HvCallHpt_findValid interface is as follows:
 175          * 0xffffffffffffffff : No entry found.
 176          * 0x00000000xxxxxxxx : Entry found in primary group, slot x
 177          * 0x80000000xxxxxxxx : Entry found in secondary group, slot x
 178          */
 179         slot = HvCallHpt_findValid(&hpte, vpn);
 180         if (hpte.dw0.dw0.v) {
 181                 if (slot < 0) {
 182                         slot &= 0x7fffffffffffffff;
 183                         slot = -slot;
 184                 }
 185         } else
 186                 slot = -1;
 187         return slot;
 188 }
 189
 190 /*
 191  * Update the page protection bits. Intended to be used to create
 192  * guard pages for kernel data structures on pages which are bolted
 193  * in the HPT. Assumes pages being operated on will not be stolen.
 194  * Does not work on large pages.
 195  *
 196  * No need to lock here because we should be the only user.
 197  */
 198 static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea)
 199 {
 200         unsigned long vsid,va,vpn;
 201         long slot;
 202
 203         vsid = get_kernel_vsid(ea);
 204         va = (vsid << 28) | (ea & 0x0fffffff);
 205         vpn = va >> PAGE_SHIFT;
 206         slot = iSeries_hpte_find(vpn);
 207         if (slot == -1)
 208                 panic("updateboltedpp: Could not find page to bolt\n");
 209         HvCallHpt_setPp(slot, newpp);
 210 }
 211
 212 static void iSeries_hpte_invalidate(unsigned long slot, unsigned long va,
 213                                     int large, int local)
 214 {
 215         HPTE lhpte;
 216         unsigned long avpn = va >> 23;
 217         unsigned long flags;
 218
 219         local_irq_save(flags);
 220
 221         iSeries_hlock(slot);
 222
 223         lhpte.dw0.dword0 = iSeries_hpte_getword0(slot);
 224
 225         if ((lhpte.dw0.dw0.avpn == avpn) && lhpte.dw0.dw0.v)
 226                 HvCallHpt_invalidateSetSwBitsGet(slot, 0, 0);
 227
 228         iSeries_hunlock(slot);
 229
 230         local_irq_restore(flags);
 231 }
 232
 233 void hpte_init_iSeries(void)
 234 {
 235         ppc_md.hpte_invalidate  = iSeries_hpte_invalidate;
 236         ppc_md.hpte_updatepp    = iSeries_hpte_updatepp;
 237         ppc_md.hpte_updateboltedpp = iSeries_hpte_updateboltedpp;
 238         ppc_md.hpte_insert      = iSeries_hpte_insert;
 239         ppc_md.hpte_remove      = iSeries_hpte_remove;
 240
 241         htab_finish_init();
 242 }