arch/powerpc/sysdev/bestcomm/sram.c

   1 /*
   2  * Simple memory allocator for on-board SRAM
   3  *
   4  *
   5  * Maintainer : Sylvain Munaut <tnt@246tNt.com>
   6  *
   7  * Copyright (C) 2005 Sylvain Munaut <tnt@246tNt.com>
   8  *
   9  * This file is licensed under the terms of the GNU General Public License
  10  * version 2. This program is licensed "as is" without any warranty of any
  11  * kind, whether express or implied.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/spinlock.h>
  18 #include <linux/string.h>
  19 #include <linux/ioport.h>
  20 #include <linux/of.h>
  21
  22 #include <asm/io.h>
  23 #include <asm/mmu.h>
  24
  25 #include "sram.h"
  26
  27
  28 /* Struct keeping our 'state' */
  29 struct bcom_sram *bcom_sram = NULL;
  30 EXPORT_SYMBOL_GPL(bcom_sram);   /* needed for inline functions */
  31
  32
  33 /* ======================================================================== */
  34 /* Public API                                                               */
  35 /* ======================================================================== */
  36 /* DO NOT USE in interrupts, if needed in irq handler, we should use the
  37    _irqsave version of the spin_locks */
  38
  39 int bcom_sram_init(struct device_node *sram_node, char *owner)
  40 {
  41         int rv;
  42         const u32 *regaddr_p;
  43         u64 regaddr64, size64;
  44         unsigned int psize;
  45
  46         /* Create our state struct */
  47         if (bcom_sram) {
  48                 printk(KERN_ERR "%s: bcom_sram_init: "
  49                         "Already initialized !\n", owner);
  50                 return -EBUSY;
  51         }
  52
  53         bcom_sram = kmalloc(sizeof(struct bcom_sram), GFP_KERNEL);
  54         if (!bcom_sram) {
  55                 printk(KERN_ERR "%s: bcom_sram_init: "
  56                         "Couldn't allocate internal state !\n", owner);
  57                 return -ENOMEM;
  58         }
  59
  60         /* Get address and size of the sram */
  61         regaddr_p = of_get_address(sram_node, 0, &size64, NULL);
  62         if (!regaddr_p) {
  63                 printk(KERN_ERR "%s: bcom_sram_init: "
  64                         "Invalid device node !\n", owner);
  65                 rv = -EINVAL;
  66                 goto error_free;
  67         }
  68
  69         regaddr64 = of_translate_address(sram_node, regaddr_p);
  70
  71         bcom_sram->base_phys = (phys_addr_t) regaddr64;
  72         bcom_sram->size = (unsigned int) size64;
  73
  74         /* Request region */
  75         if (!request_mem_region(bcom_sram->base_phys, bcom_sram->size, owner)) {
  76                 printk(KERN_ERR "%s: bcom_sram_init: "
  77                         "Couldn't request region !\n", owner);
  78                 rv = -EBUSY;
  79                 goto error_free;
  80         }
  81
  82         /* Map SRAM */
  83                 /* sram is not really __iomem */
  84         bcom_sram->base_virt = (void*) ioremap(bcom_sram->base_phys, bcom_sram->size);
  85
  86         if (!bcom_sram->base_virt) {
  87                 printk(KERN_ERR "%s: bcom_sram_init: "
  88                         "Map error SRAM zone 0x%08lx (0x%0x)!\n",
  89                         owner, (long)bcom_sram->base_phys, bcom_sram->size );
  90                 rv = -ENOMEM;
  91                 goto error_release;
  92         }
  93
  94         /* Create an rheap (defaults to 32 bits word alignment) */
  95         bcom_sram->rh = rh_create(4);
  96
  97         /* Attach the free zones */
  98 #if 0
  99         /* Currently disabled ... for future use only */
 100         reg_addr_p = of_get_property(sram_node, "available", &psize);
 101 #else
 102         regaddr_p = NULL;
 103         psize = 0;
 104 #endif
 105
 106         if (!regaddr_p || !psize) {
 107                 /* Attach the whole zone */
 108                 rh_attach_region(bcom_sram->rh, 0, bcom_sram->size);
 109         } else {
 110                 /* Attach each zone independently */
 111                 while (psize >= 2 * sizeof(u32)) {
 112                         phys_addr_t zbase = of_translate_address(sram_node, regaddr_p);
 113                         rh_attach_region(bcom_sram->rh, zbase - bcom_sram->base_phys, regaddr_p[1]);
 114                         regaddr_p += 2;
 115                         psize -= 2 * sizeof(u32);
 116                 }
 117         }
 118
 119         /* Init our spinlock */
 120         spin_lock_init(&bcom_sram->lock);
 121
 122         return 0;
 123
 124 error_release:
 125         release_mem_region(bcom_sram->base_phys, bcom_sram->size);
 126 error_free:
 127         kfree(bcom_sram);
 128         bcom_sram = NULL;
 129
 130         return rv;
 131 }
 132 EXPORT_SYMBOL_GPL(bcom_sram_init);
 133
 134 void bcom_sram_cleanup(void)
 135 {
 136         /* Free resources */
 137         if (bcom_sram) {
 138                 rh_destroy(bcom_sram->rh);
 139                 iounmap((void __iomem *)bcom_sram->base_virt);
 140                 release_mem_region(bcom_sram->base_phys, bcom_sram->size);
 141                 kfree(bcom_sram);
 142                 bcom_sram = NULL;
 143         }
 144 }
 145 EXPORT_SYMBOL_GPL(bcom_sram_cleanup);
 146
 147 void* bcom_sram_alloc(int size, int align, phys_addr_t *phys)
 148 {
 149         unsigned long offset;
 150
 151         spin_lock(&bcom_sram->lock);
 152         offset = rh_alloc_align(bcom_sram->rh, size, align, NULL);
 153         spin_unlock(&bcom_sram->lock);
 154
 155         if (IS_ERR_VALUE(offset))
 156                 return NULL;
 157
 158         *phys = bcom_sram->base_phys + offset;
 159         return bcom_sram->base_virt + offset;
 160 }
 161 EXPORT_SYMBOL_GPL(bcom_sram_alloc);
 162
 163 void bcom_sram_free(void *ptr)
 164 {
 165         unsigned long offset;
 166
 167         if (!ptr)
 168                 return;
 169
 170         offset = ptr - bcom_sram->base_virt;
 171
 172         spin_lock(&bcom_sram->lock);
 173         rh_free(bcom_sram->rh, offset);
 174         spin_unlock(&bcom_sram->lock);
 175 }
 176 EXPORT_SYMBOL_GPL(bcom_sram_free);
 177