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 #include <asm/bus-sh.h>
  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 void *voyagergx_consistent_alloc(struct device *dev, size_t size,
  34                                  dma_addr_t *handle, int flag)
  35 {
  36         struct list_head *list = &voya_alloc_list;
  37         struct voya_alloc_entry *entry;
  38         struct sh_dev *shdev = to_sh_dev(dev);
  39         unsigned long start, end;
  40         unsigned long flags;
  41
  42         /*
  43          * The SM501 contains an integrated 8051 with its own SRAM.
  44          * Devices within the cchip can all hook into the 8051 SRAM.
  45          * We presently use this for the OHCI.
  46          *
  47          * Everything else goes through consistent_alloc().
  48          */
  49         if (!dev || dev->bus != &sh_bus_types[SH_BUS_VIRT] ||
  50                    (dev->bus == &sh_bus_types[SH_BUS_VIRT] &&
  51                     shdev->dev_id != SH_DEV_ID_USB_OHCI))
  52                 return NULL;
  53
  54         start = OHCI_SRAM_START + OHCI_HCCA_SIZE;
  55
  56         entry = kmalloc(sizeof(struct voya_alloc_entry), GFP_ATOMIC);
  57         if (!entry)
  58                 return ERR_PTR(-ENOMEM);
  59
  60         entry->len = (size + 15) & ~15;
  61
  62         /*
  63          * The basis for this allocator is dwmw2's malloc.. the
  64          * Matrox allocator :-)
  65          */
  66         spin_lock_irqsave(&voya_list_lock, flags);
  67         list_for_each(list, &voya_alloc_list) {
  68                 struct voya_alloc_entry *p;
  69
  70                 p = list_entry(list, struct voya_alloc_entry, list);
  71
  72                 if (p->ofs - start >= size)
  73                         goto out;
  74
  75                 start = p->ofs + p->len;
  76         }
  77
  78         end  = start + (OHCI_SRAM_SIZE  - OHCI_HCCA_SIZE);
  79         list = &voya_alloc_list;
  80
  81         if (end - start >= size) {
  82 out:
  83                 entry->ofs = start;
  84                 list_add_tail(&entry->list, list);
  85                 spin_unlock_irqrestore(&voya_list_lock, flags);
  86
  87                 *handle = start;
  88                 return (void *)start;
  89         }
  90
  91         kfree(entry);
  92         spin_unlock_irqrestore(&voya_list_lock, flags);
  93
  94         return ERR_PTR(-EINVAL);
  95 }
  96
  97 int voyagergx_consistent_free(struct device *dev, size_t size,
  98                               void *vaddr, dma_addr_t handle)
  99 {
 100         struct voya_alloc_entry *entry;
 101         struct sh_dev *shdev = to_sh_dev(dev);
 102         unsigned long flags;
 103
 104         if (!dev || dev->bus != &sh_bus_types[SH_BUS_VIRT] ||
 105                    (dev->bus == &sh_bus_types[SH_BUS_VIRT] &&
 106                     shdev->dev_id != SH_DEV_ID_USB_OHCI))
 107                 return -EINVAL;
 108
 109         spin_lock_irqsave(&voya_list_lock, flags);
 110         list_for_each_entry(entry, &voya_alloc_list, list) {
 111                 if (entry->ofs != handle)
 112                         continue;
 113
 114                 list_del(&entry->list);
 115                 kfree(entry);
 116
 117                 break;
 118         }
 119         spin_unlock_irqrestore(&voya_list_lock, flags);
 120
 121         return 0;
 122 }
 123
 124 EXPORT_SYMBOL(voyagergx_consistent_alloc);
 125 EXPORT_SYMBOL(voyagergx_consistent_free);
 126