arch/powerpc/sysdev/fsl_85xx_cache_sram.c

   1 /*
   2  * Copyright 2009-2010 Freescale Semiconductor, Inc.
   3  *
   4  * Simple memory allocator abstraction for QorIQ (P1/P2) based Cache-SRAM
   5  *
   6  * Author: Vivek Mahajan <vivek.mahajan@freescale.com>
   7  *
   8  * This file is derived from the original work done
   9  * by Sylvain Munaut for the Bestcomm SRAM allocator.
  10  *
  11  * This program is free software; you can redistribute  it and/or modify it
  12  * under  the terms of  the GNU General  Public License as published by the
  13  * Free Software Foundation;  either version 2 of the  License, or (at your
  14  * option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24  */
  25
  26 #include <linux/kernel.h>
  27 #include <linux/export.h>
  28 #include <linux/slab.h>
  29 #include <linux/err.h>
  30 #include <linux/of_platform.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/fsl_85xx_cache_sram.h>
  33
  34 #include "fsl_85xx_cache_ctlr.h"
  35
  36 struct mpc85xx_cache_sram *cache_sram;
  37
  38 void *mpc85xx_cache_sram_alloc(unsigned int size,
  39                                 phys_addr_t *phys, unsigned int align)
  40 {
  41         unsigned long offset;
  42         unsigned long flags;
  43
  44         if (unlikely(cache_sram == NULL))
  45                 return NULL;
  46
  47         if (!size || (size > cache_sram->size) || (align > cache_sram->size)) {
  48                 pr_err("%s(): size(=%x) or align(=%x) zero or too big\n",
  49                         __func__, size, align);
  50                 return NULL;
  51         }
  52
  53         if ((align & (align - 1)) || align <= 1) {
  54                 pr_err("%s(): align(=%x) must be power of two and >1\n",
  55                         __func__, align);
  56                 return NULL;
  57         }
  58
  59         spin_lock_irqsave(&cache_sram->lock, flags);
  60         offset = rh_alloc_align(cache_sram->rh, size, align, NULL);
  61         spin_unlock_irqrestore(&cache_sram->lock, flags);
  62
  63         if (IS_ERR_VALUE(offset))
  64                 return NULL;
  65
  66         *phys = cache_sram->base_phys + offset;
  67
  68         return (unsigned char *)cache_sram->base_virt + offset;
  69 }
  70 EXPORT_SYMBOL(mpc85xx_cache_sram_alloc);
  71
  72 void mpc85xx_cache_sram_free(void *ptr)
  73 {
  74         unsigned long flags;
  75         BUG_ON(!ptr);
  76
  77         spin_lock_irqsave(&cache_sram->lock, flags);
  78         rh_free(cache_sram->rh, ptr - cache_sram->base_virt);
  79         spin_unlock_irqrestore(&cache_sram->lock, flags);
  80 }
  81 EXPORT_SYMBOL(mpc85xx_cache_sram_free);
  82
  83 int __init instantiate_cache_sram(struct platform_device *dev,
  84                 struct sram_parameters sram_params)
  85 {
  86         int ret = 0;
  87
  88         if (cache_sram) {
  89                 dev_err(&dev->dev, "Already initialized cache-sram\n");
  90                 return -EBUSY;
  91         }
  92
  93         cache_sram = kzalloc(sizeof(struct mpc85xx_cache_sram), GFP_KERNEL);
  94         if (!cache_sram) {
  95                 dev_err(&dev->dev, "Out of memory for cache_sram structure\n");
  96                 return -ENOMEM;
  97         }
  98
  99         cache_sram->base_phys = sram_params.sram_offset;
 100         cache_sram->size = sram_params.sram_size;
 101
 102         if (!request_mem_region(cache_sram->base_phys, cache_sram->size,
 103                                                 "fsl_85xx_cache_sram")) {
 104                 dev_err(&dev->dev, "%pOF: request memory failed\n",
 105                                 dev->dev.of_node);
 106                 ret = -ENXIO;
 107                 goto out_free;
 108         }
 109
 110         cache_sram->base_virt = ioremap_prot(cache_sram->base_phys,
 111                                 cache_sram->size, _PAGE_COHERENT | PAGE_KERNEL);
 112         if (!cache_sram->base_virt) {
 113                 dev_err(&dev->dev, "%pOF: ioremap_prot failed\n",
 114                                 dev->dev.of_node);
 115                 ret = -ENOMEM;
 116                 goto out_release;
 117         }
 118
 119         cache_sram->rh = rh_create(sizeof(unsigned int));
 120         if (IS_ERR(cache_sram->rh)) {
 121                 dev_err(&dev->dev, "%pOF: Unable to create remote heap\n",
 122                                 dev->dev.of_node);
 123                 ret = PTR_ERR(cache_sram->rh);
 124                 goto out_unmap;
 125         }
 126
 127         rh_attach_region(cache_sram->rh, 0, cache_sram->size);
 128         spin_lock_init(&cache_sram->lock);
 129
 130         dev_info(&dev->dev, "[base:0x%llx, size:0x%x] configured and loaded\n",
 131                 (unsigned long long)cache_sram->base_phys, cache_sram->size);
 132
 133         return 0;
 134
 135 out_unmap:
 136         iounmap(cache_sram->base_virt);
 137
 138 out_release:
 139         release_mem_region(cache_sram->base_phys, cache_sram->size);
 140
 141 out_free:
 142         kfree(cache_sram);
 143         return ret;
 144 }
 145
 146 void remove_cache_sram(struct platform_device *dev)
 147 {
 148         BUG_ON(!cache_sram);
 149
 150         rh_detach_region(cache_sram->rh, 0, cache_sram->size);
 151         rh_destroy(cache_sram->rh);
 152
 153         iounmap(cache_sram->base_virt);
 154         release_mem_region(cache_sram->base_phys, cache_sram->size);
 155
 156         kfree(cache_sram);
 157         cache_sram = NULL;
 158
 159         dev_info(&dev->dev, "MPC85xx Cache-SRAM driver unloaded\n");
 160 }