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) 2001-2006 Silicon Graphics, Inc. All rights reserved.
   7  */
   8
   9 #include <linux/types.h>
  10 #include <asm/sn/sn_sal.h>
  11 #include <asm/sn/pcibr_provider.h>
  12 #include <asm/sn/pcibus_provider_defs.h>
  13 #include <asm/sn/pcidev.h>
  14
  15 int pcibr_invalidate_ate;       /* 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                      u64 value)
  22 {
  23         u64 *ate = ate_resource->ate;
  24         int index;
  25         int length = 0;
  26
  27         for (index = start; length < number; index++, length++)
  28                 ate[index] = value;
  29 }
  30
  31 /*
  32  * find_free_ate:  Find the first free ate index starting from the given
  33  *                 index for the desired consecutive count.
  34  */
  35 static int find_free_ate(struct ate_resource *ate_resource, int start,
  36                          int count)
  37 {
  38         u64 *ate = ate_resource->ate;
  39         int index;
  40         int start_free;
  41
  42         for (index = start; index < ate_resource->num_ate;) {
  43                 if (!ate[index]) {
  44                         int i;
  45                         int free;
  46                         free = 0;
  47                         start_free = index;     /* Found start free ate */
  48                         for (i = start_free; i < ate_resource->num_ate; i++) {
  49                                 if (!ate[i]) {  /* This is free */
  50                                         if (++free == count)
  51                                                 return start_free;
  52                                 } else {
  53                                         index = i + 1;
  54                                         break;
  55                                 }
  56                         }
  57                         if (i >= ate_resource->num_ate)
  58                                 return -1;
  59                 } else
  60                         index++;        /* Try next ate */
  61         }
  62
  63         return -1;
  64 }
  65
  66 /*
  67  * free_ate_resource:  Free the requested number of ATEs.
  68  */
  69 static inline void free_ate_resource(struct ate_resource *ate_resource,
  70                                      int start)
  71 {
  72         mark_ate(ate_resource, start, ate_resource->ate[start], 0);
  73         if ((ate_resource->lowest_free_index > start) ||
  74             (ate_resource->lowest_free_index < 0))
  75                 ate_resource->lowest_free_index = start;
  76 }
  77
  78 /*
  79  * alloc_ate_resource:  Allocate the requested number of ATEs.
  80  */
  81 static inline int alloc_ate_resource(struct ate_resource *ate_resource,
  82                                      int ate_needed)
  83 {
  84         int start_index;
  85
  86         /*
  87          * Check for ate exhaustion.
  88          */
  89         if (ate_resource->lowest_free_index < 0)
  90                 return -1;
  91
  92         /*
  93          * Find the required number of free consecutive ates.
  94          */
  95         start_index =
  96             find_free_ate(ate_resource, ate_resource->lowest_free_index,
  97                           ate_needed);
  98         if (start_index >= 0)
  99                 mark_ate(ate_resource, start_index, ate_needed, ate_needed);
 100
 101         ate_resource->lowest_free_index =
 102             find_free_ate(ate_resource, ate_resource->lowest_free_index, 1);
 103
 104         return start_index;
 105 }
 106
 107 /*
 108  * Allocate "count" contiguous Bridge Address Translation Entries
 109  * on the specified bridge to be used for PCI to XTALK mappings.
 110  * Indices in rm map range from 1..num_entries.  Indices returned
 111  * to caller range from 0..num_entries-1.
 112  *
 113  * Return the start index on success, -1 on failure.
 114  */
 115 int pcibr_ate_alloc(struct pcibus_info *pcibus_info, int count)
 116 {
 117         int status;
 118         unsigned long flags;
 119
 120         spin_lock_irqsave(&pcibus_info->pbi_lock, flags);
 121         status = alloc_ate_resource(&pcibus_info->pbi_int_ate_resource, count);
 122         spin_unlock_irqrestore(&pcibus_info->pbi_lock, flags);
 123
 124         return status;
 125 }
 126
 127 /*
 128  * Setup an Address Translation Entry as specified.  Use either the Bridge
 129  * internal maps or the external map RAM, as appropriate.
 130  */
 131 static inline u64 __iomem *pcibr_ate_addr(struct pcibus_info *pcibus_info,
 132                                        int ate_index)
 133 {
 134         if (ate_index < pcibus_info->pbi_int_ate_size) {
 135                 return pcireg_int_ate_addr(pcibus_info, ate_index);
 136         }
 137         panic("pcibr_ate_addr: invalid ate_index 0x%x", ate_index);
 138 }
 139
 140 /*
 141  * Update the ate.
 142  */
 143 void inline
 144 ate_write(struct pcibus_info *pcibus_info, int ate_index, int count,
 145           volatile u64 ate)
 146 {
 147         while (count-- > 0) {
 148                 if (ate_index < pcibus_info->pbi_int_ate_size) {
 149                         pcireg_int_ate_set(pcibus_info, ate_index, ate);
 150                 } else {
 151                         panic("ate_write: invalid ate_index 0x%x", ate_index);
 152                 }
 153                 ate_index++;
 154                 ate += IOPGSIZE;
 155         }
 156
 157         pcireg_tflush_get(pcibus_info); /* wait until Bridge PIO complete */
 158 }
 159
 160 void pcibr_ate_free(struct pcibus_info *pcibus_info, int index)
 161 {
 162
 163         volatile u64 ate;
 164         int count;
 165         unsigned long flags;
 166
 167         if (pcibr_invalidate_ate) {
 168                 /* For debugging purposes, clear the valid bit in the ATE */
 169                 ate = *pcibr_ate_addr(pcibus_info, index);
 170                 count = pcibus_info->pbi_int_ate_resource.ate[index];
 171                 ate_write(pcibus_info, index, count, (ate & ~PCI32_ATE_V));
 172         }
 173
 174         spin_lock_irqsave(&pcibus_info->pbi_lock, flags);
 175         free_ate_resource(&pcibus_info->pbi_int_ate_resource, index);
 176         spin_unlock_irqrestore(&pcibus_info->pbi_lock, flags);
 177 }