drivers/dma/bestcomm/sram.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Simple memory allocator for on-board SRAM
   4  *
   5  * Maintainer : Sylvain Munaut <[email protected]>
   6  *
   7  * Copyright (C) 2005 Sylvain Munaut <[email protected]>
   8  */
   9
  10 #include <linux/err.h>
  11 #include <linux/kernel.h>
  12 #include <linux/export.h>
  13 #include <linux/slab.h>
  14 #include <linux/spinlock.h>
  15 #include <linux/string.h>
  16 #include <linux/ioport.h>
  17 #include <linux/of.h>
  18 #include <linux/of_address.h>
  19
  20 #include <asm/io.h>
  21 #include <asm/mmu.h>
  22
  23 #include <linux/fsl/bestcomm/sram.h>
  24
  25
  26 /* Struct keeping our 'state' */
  27 struct bcom_sram *bcom_sram = NULL;
  28 EXPORT_SYMBOL_GPL(bcom_sram);   /* needed for inline functions */
  29
  30
  31 /* ======================================================================== */
  32 /* Public API                                                               */
  33 /* ======================================================================== */
  34 /* DO NOT USE in interrupts, if needed in irq handler, we should use the
  35    _irqsave version of the spin_locks */
  36
  37 int bcom_sram_init(struct device_node *sram_node, char *owner)
  38 {
  39         int rv;
  40         const u32 *regaddr_p;
  41         struct resource res;
  42         unsigned int psize;
  43
  44         /* Create our state struct */
  45         if (bcom_sram) {
  46                 printk(KERN_ERR "%s: bcom_sram_init: "
  47                         "Already initialized !\n", owner);
  48                 return -EBUSY;
  49         }
  50
  51         bcom_sram = kmalloc(sizeof(struct bcom_sram), GFP_KERNEL);
  52         if (!bcom_sram) {
  53                 printk(KERN_ERR "%s: bcom_sram_init: "
  54                         "Couldn't allocate internal state !\n", owner);
  55                 return -ENOMEM;
  56         }
  57
  58         /* Get address and size of the sram */
  59         rv = of_address_to_resource(sram_node, 0, &res);
  60         if (rv) {
  61                 printk(KERN_ERR "%s: bcom_sram_init: "
  62                         "Invalid device node !\n", owner);
  63                 goto error_free;
  64         }
  65
  66         bcom_sram->base_phys = res.start;
  67         bcom_sram->size = resource_size(&res);
  68
  69         /* Request region */
  70         if (!request_mem_region(res.start, resource_size(&res), owner)) {
  71                 printk(KERN_ERR "%s: bcom_sram_init: "
  72                         "Couldn't request region !\n", owner);
  73                 rv = -EBUSY;
  74                 goto error_free;
  75         }
  76
  77         /* Map SRAM */
  78                 /* sram is not really __iomem */
  79         bcom_sram->base_virt = (void *)ioremap(res.start, resource_size(&res));
  80
  81         if (!bcom_sram->base_virt) {
  82                 printk(KERN_ERR "%s: bcom_sram_init: "
  83                         "Map error SRAM zone 0x%08lx (0x%0x)!\n",
  84                         owner, (long)bcom_sram->base_phys, bcom_sram->size );
  85                 rv = -ENOMEM;
  86                 goto error_release;
  87         }
  88
  89         /* Create an rheap (defaults to 32 bits word alignment) */
  90         bcom_sram->rh = rh_create(4);
  91
  92         /* Attach the free zones */
  93 #if 0
  94         /* Currently disabled ... for future use only */
  95         reg_addr_p = of_get_property(sram_node, "available", &psize);
  96 #else
  97         regaddr_p = NULL;
  98         psize = 0;
  99 #endif
 100
 101         if (!regaddr_p || !psize) {
 102                 /* Attach the whole zone */
 103                 rh_attach_region(bcom_sram->rh, 0, bcom_sram->size);
 104         } else {
 105                 /* Attach each zone independently */
 106                 while (psize >= 2 * sizeof(u32)) {
 107                         phys_addr_t zbase = of_translate_address(sram_node, regaddr_p);
 108                         rh_attach_region(bcom_sram->rh, zbase - bcom_sram->base_phys, regaddr_p[1]);
 109                         regaddr_p += 2;
 110                         psize -= 2 * sizeof(u32);
 111                 }
 112         }
 113
 114         /* Init our spinlock */
 115         spin_lock_init(&bcom_sram->lock);
 116
 117         return 0;
 118
 119 error_release:
 120         release_mem_region(res.start, resource_size(&res));
 121 error_free:
 122         kfree(bcom_sram);
 123         bcom_sram = NULL;
 124
 125         return rv;
 126 }
 127 EXPORT_SYMBOL_GPL(bcom_sram_init);
 128
 129 void bcom_sram_cleanup(void)
 130 {
 131         /* Free resources */
 132         if (bcom_sram) {
 133                 rh_destroy(bcom_sram->rh);
 134                 iounmap((void __iomem *)bcom_sram->base_virt);
 135                 release_mem_region(bcom_sram->base_phys, bcom_sram->size);
 136                 kfree(bcom_sram);
 137                 bcom_sram = NULL;
 138         }
 139 }
 140 EXPORT_SYMBOL_GPL(bcom_sram_cleanup);
 141
 142 void* bcom_sram_alloc(int size, int align, phys_addr_t *phys)
 143 {
 144         unsigned long offset;
 145
 146         spin_lock(&bcom_sram->lock);
 147         offset = rh_alloc_align(bcom_sram->rh, size, align, NULL);
 148         spin_unlock(&bcom_sram->lock);
 149
 150         if (IS_ERR_VALUE(offset))
 151                 return NULL;
 152
 153         *phys = bcom_sram->base_phys + offset;
 154         return bcom_sram->base_virt + offset;
 155 }
 156 EXPORT_SYMBOL_GPL(bcom_sram_alloc);
 157
 158 void bcom_sram_free(void *ptr)
 159 {
 160         unsigned long offset;
 161
 162         if (!ptr)
 163                 return;
 164
 165         offset = ptr - bcom_sram->base_virt;
 166
 167         spin_lock(&bcom_sram->lock);
 168         rh_free(bcom_sram->rh, offset);
 169         spin_unlock(&bcom_sram->lock);
 170 }
 171 EXPORT_SYMBOL_GPL(bcom_sram_free);