arch/sh/cchips/voyagergx/consistent.c

   1 /*
   2  * arch/sh/cchips/voyagergx/consistent.c
   3  *
   4  * Copyright (C) 2004  Paul Mundt
   5  *
   6  * This file is subject to the terms and conditions of the GNU General Public
   7  * License.  See the file "COPYING" in the main directory of this archive
   8  * for more details.
   9  */
  10 #include <linux/mm.h>
  11 #include <linux/dma-mapping.h>
  12 #include <linux/slab.h>
  13 #include <linux/list.h>
  14 #include <linux/types.h>
  15 #include <linux/module.h>
  16 #include <linux/device.h>
  17 #include <asm/io.h>
  18
  19
  20 struct voya_alloc_entry {
  21         struct list_head list;
  22         unsigned long ofs;
  23         unsigned long len;
  24 };
  25
  26 static DEFINE_SPINLOCK(voya_list_lock);
  27 static LIST_HEAD(voya_alloc_list);
  28
  29 #define OHCI_SRAM_START 0xb0000000
  30 #define OHCI_HCCA_SIZE  0x100
  31 #define OHCI_SRAM_SIZE  0x10000
  32
  33 #define VOYAGER_OHCI_NAME       "voyager-ohci"
  34
  35 void *voyagergx_consistent_alloc(struct device *dev, size_t size,
  36                                  dma_addr_t *handle, gfp_t flag)
  37 {
  38         struct list_head *list = &voya_alloc_list;
  39         struct voya_alloc_entry *entry;
  40         unsigned long start, end;
  41         unsigned long flags;
  42
  43         /*
  44          * The SM501 contains an integrated 8051 with its own SRAM.
  45          * Devices within the cchip can all hook into the 8051 SRAM.
  46          * We presently use this for the OHCI.
  47          *
  48          * Everything else goes through consistent_alloc().
  49          */
  50         if (!dev || strcmp(dev->driver->name, VOYAGER_OHCI_NAME))
  51                 return NULL;
  52
  53         start = OHCI_SRAM_START + OHCI_HCCA_SIZE;
  54
  55         entry = kmalloc(sizeof(struct voya_alloc_entry), GFP_ATOMIC);
  56         if (!entry)
  57                 return ERR_PTR(-ENOMEM);
  58
  59         entry->len = (size + 15) & ~15;
  60
  61         /*
  62          * The basis for this allocator is dwmw2's malloc.. the
  63          * Matrox allocator :-)
  64          */
  65         spin_lock_irqsave(&voya_list_lock, flags);
  66         list_for_each(list, &voya_alloc_list) {
  67                 struct voya_alloc_entry *p;
  68
  69                 p = list_entry(list, struct voya_alloc_entry, list);
  70
  71                 if (p->ofs - start >= size)
  72                         goto out;
  73
  74                 start = p->ofs + p->len;
  75         }
  76
  77         end  = start + (OHCI_SRAM_SIZE  - OHCI_HCCA_SIZE);
  78         list = &voya_alloc_list;
  79
  80         if (end - start >= size) {
  81 out:
  82                 entry->ofs = start;
  83                 list_add_tail(&entry->list, list);
  84                 spin_unlock_irqrestore(&voya_list_lock, flags);
  85
  86                 *handle = start;
  87                 return (void *)start;
  88         }
  89
  90         kfree(entry);
  91         spin_unlock_irqrestore(&voya_list_lock, flags);
  92
  93         return ERR_PTR(-EINVAL);
  94 }
  95
  96 int voyagergx_consistent_free(struct device *dev, size_t size,
  97                               void *vaddr, dma_addr_t handle)
  98 {
  99         struct voya_alloc_entry *entry;
 100         unsigned long flags;
 101
 102         if (!dev || strcmp(dev->driver->name, VOYAGER_OHCI_NAME))
 103                 return -EINVAL;
 104
 105         spin_lock_irqsave(&voya_list_lock, flags);
 106         list_for_each_entry(entry, &voya_alloc_list, list) {
 107                 if (entry->ofs != handle)
 108                         continue;
 109
 110                 list_del(&entry->list);
 111                 kfree(entry);
 112
 113                 break;
 114         }
 115         spin_unlock_irqrestore(&voya_list_lock, flags);
 116
 117         return 0;
 118 }
 119
 120 EXPORT_SYMBOL(voyagergx_consistent_alloc);
 121 EXPORT_SYMBOL(voyagergx_consistent_free);