arch/ia64/sn/pci/pcibr/pcibr_ate.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2001-2004 Silicon Graphics, Inc. All rights reserved.
   7  */
   8
   9 #include <linux/types.h>
  10 #include <asm/sn/sn_sal.h>
  11 #include <asm/sn/pcibus_provider_defs.h>
  12 #include <asm/sn/pcidev.h>
  13 #include "pci/pcibr_provider.h"
  14
  15 int pcibr_invalidate_ate = 0;   /* by default don't invalidate ATE on free */
  16
  17 /*
  18  * mark_ate: Mark the ate as either free or inuse.
  19  */
  20 static void mark_ate(struct ate_resource *ate_resource, int start, int number,
  21                      uint64_t value)
  22 {
  23
  24         uint64_t *ate = ate_resource->ate;
  25         int index;
  26         int length = 0;
  27
  28         for (index = start; length < number; index++, length++)
  29                 ate[index] = value;
  30
  31 }
  32
  33 /*
  34  * find_free_ate:  Find the first free ate index starting from the given
  35  *                 index for the desired consequtive count.
  36  */
  37 static int find_free_ate(struct ate_resource *ate_resource, int start,
  38                          int count)
  39 {
  40
  41         uint64_t *ate = ate_resource->ate;
  42         int index;
  43         int start_free;
  44
  45         for (index = start; index < ate_resource->num_ate;) {
  46                 if (!ate[index]) {
  47                         int i;
  48                         int free;
  49                         free = 0;
  50                         start_free = index;     /* Found start free ate */
  51                         for (i = start_free; i < ate_resource->num_ate; i++) {
  52                                 if (!ate[i]) {  /* This is free */
  53                                         if (++free == count)
  54                                                 return start_free;
  55                                 } else {
  56                                         index = i + 1;
  57                                         break;
  58                                 }
  59                         }
  60                 } else
  61                         index++;        /* Try next ate */
  62         }
  63
  64         return -1;
  65 }
  66
  67 /*
  68  * free_ate_resource:  Free the requested number of ATEs.
  69  */
  70 static inline void free_ate_resource(struct ate_resource *ate_resource,
  71                                      int start)
  72 {
  73
  74         mark_ate(ate_resource, start, ate_resource->ate[start], 0);
  75         if ((ate_resource->lowest_free_index > start) ||
  76             (ate_resource->lowest_free_index < 0))
  77                 ate_resource->lowest_free_index = start;
  78
  79 }
  80
  81 /*
  82  * alloc_ate_resource:  Allocate the requested number of ATEs.
  83  */
  84 static inline int alloc_ate_resource(struct ate_resource *ate_resource,
  85                                      int ate_needed)
  86 {
  87
  88         int start_index;
  89
  90         /*
  91          * Check for ate exhaustion.
  92          */
  93         if (ate_resource->lowest_free_index < 0)
  94                 return -1;
  95
  96         /*
  97          * Find the required number of free consequtive ates.
  98          */
  99         start_index =
 100             find_free_ate(ate_resource, ate_resource->lowest_free_index,
 101                           ate_needed);
 102         if (start_index >= 0)
 103                 mark_ate(ate_resource, start_index, ate_needed, ate_needed);
 104
 105         ate_resource->lowest_free_index =
 106             find_free_ate(ate_resource, ate_resource->lowest_free_index, 1);
 107
 108         return start_index;
 109 }
 110
 111 /*
 112  * Allocate "count" contiguous Bridge Address Translation Entries
 113  * on the specified bridge to be used for PCI to XTALK mappings.
 114  * Indices in rm map range from 1..num_entries.  Indicies returned
 115  * to caller range from 0..num_entries-1.
 116  *
 117  * Return the start index on success, -1 on failure.
 118  */
 119 int pcibr_ate_alloc(struct pcibus_info *pcibus_info, int count)
 120 {
 121         int status = 0;
 122         uint64_t flag;
 123
 124         flag = pcibr_lock(pcibus_info);
 125         status = alloc_ate_resource(&pcibus_info->pbi_int_ate_resource, count);
 126
 127         if (status < 0) {
 128                 /* Failed to allocate */
 129                 pcibr_unlock(pcibus_info, flag);
 130                 return -1;
 131         }
 132
 133         pcibr_unlock(pcibus_info, flag);
 134
 135         return status;
 136 }
 137
 138 /*
 139  * Setup an Address Translation Entry as specified.  Use either the Bridge
 140  * internal maps or the external map RAM, as appropriate.
 141  */
 142 static inline uint64_t *pcibr_ate_addr(struct pcibus_info *pcibus_info,
 143                                        int ate_index)
 144 {
 145         if (ate_index < pcibus_info->pbi_int_ate_size) {
 146                 return pcireg_int_ate_addr(pcibus_info, ate_index);
 147         }
 148         panic("pcibr_ate_addr: invalid ate_index 0x%x", ate_index);
 149 }
 150
 151 /*
 152  * Update the ate.
 153  */
 154 void inline
 155 ate_write(struct pcibus_info *pcibus_info, int ate_index, int count,
 156           volatile uint64_t ate)
 157 {
 158         while (count-- > 0) {
 159                 if (ate_index < pcibus_info->pbi_int_ate_size) {
 160                         pcireg_int_ate_set(pcibus_info, ate_index, ate);
 161                 } else {
 162                         panic("ate_write: invalid ate_index 0x%x", ate_index);
 163                 }
 164                 ate_index++;
 165                 ate += IOPGSIZE;
 166         }
 167
 168         pcireg_tflush_get(pcibus_info); /* wait until Bridge PIO complete */
 169 }
 170
 171 void pcibr_ate_free(struct pcibus_info *pcibus_info, int index)
 172 {
 173
 174         volatile uint64_t ate;
 175         int count;
 176         uint64_t flags;
 177
 178         if (pcibr_invalidate_ate) {
 179                 /* For debugging purposes, clear the valid bit in the ATE */
 180                 ate = *pcibr_ate_addr(pcibus_info, index);
 181                 count = pcibus_info->pbi_int_ate_resource.ate[index];
 182                 ate_write(pcibus_info, index, count, (ate & ~PCI32_ATE_V));
 183         }
 184
 185         flags = pcibr_lock(pcibus_info);
 186         free_ate_resource(&pcibus_info->pbi_int_ate_resource, index);
 187         pcibr_unlock(pcibus_info, flags);
 188 }