LXR linux/arch/x86/kernel/tce

   1/*
   2 * This file manages the translation entries for the IBM Calgary IOMMU.
   3 *
   4 * Derived from arch/powerpc/platforms/pseries/iommu.c
   5 *
   6 * Copyright (C) IBM Corporation, 2006
   7 *
   8 * Author: Jon Mason <jdmason@us.ibm.com>
   9 * Author: Muli Ben-Yehuda <muli@il.ibm.com>
  10 *
  11 * This program is free software; you can redistribute it and/or modify
  12 * it under the terms of the GNU General Public License as published by
  13 * the Free Software Foundation; either version 2 of the License, or
  14 * (at your 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  24 */
  25
  26#include <linux/types.h>
  27#include <linux/slab.h>
  28#include <linux/mm.h>
  29#include <linux/spinlock.h>
  30#include <linux/string.h>
  31#include <linux/pci.h>
  32#include <linux/dma-mapping.h>
  33#include <linux/bootmem.h>
  34#include <asm/tce.h>
  35#include <asm/calgary.h>
  36#include <asm/proto.h>
  37#include <asm/cacheflush.h>
  38
  39/* flush a tce at 'tceaddr' to main memory */
  40static inline void flush_tce(void* tceaddr)
  41{
  42        /* a single tce can't cross a cache line */
  43        if (cpu_has_clflush)
  44                clflush(tceaddr);
  45        else
  46                wbinvd();
  47}
  48
  49void tce_build(struct iommu_table *tbl, unsigned long index,
  50        unsigned int npages, unsigned long uaddr, int direction)
  51{
  52        u64* tp;
  53        u64 t;
  54        u64 rpn;
  55
  56        t = (1 << TCE_READ_SHIFT);
  57        if (direction != DMA_TO_DEVICE)
  58                t |= (1 << TCE_WRITE_SHIFT);
  59
  60        tp = ((u64*)tbl->it_base) + index;
  61
  62        while (npages--) {
  63                rpn = (virt_to_bus((void*)uaddr)) >> PAGE_SHIFT;
  64                t &= ~TCE_RPN_MASK;
  65                t |= (rpn << TCE_RPN_SHIFT);
  66
  67                *tp = cpu_to_be64(t);
  68                flush_tce(tp);
  69
  70                uaddr += PAGE_SIZE;
  71                tp++;
  72        }
  73}
  74
  75void tce_free(struct iommu_table *tbl, long index, unsigned int npages)
  76{
  77        u64* tp;
  78
  79        tp  = ((u64*)tbl->it_base) + index;
  80
  81        while (npages--) {
  82                *tp = cpu_to_be64(0);
  83                flush_tce(tp);
  84                tp++;
  85        }
  86}
  87
  88static inline unsigned int table_size_to_number_of_entries(unsigned char size)
  89{
  90        /*
  91         * size is the order of the table, 0-7
  92         * smallest table is 8K entries, so shift result by 13 to
  93         * multiply by 8K
  94         */
  95        return (1 << size) << 13;
  96}
  97
  98static int tce_table_setparms(struct pci_dev *dev, struct iommu_table *tbl)
  99{
 100        unsigned int bitmapsz;
 101        unsigned long bmppages;
 102        int ret;
 103
 104        tbl->it_busno = dev->bus->number;
 105
 106        /* set the tce table size - measured in entries */
 107        tbl->it_size = table_size_to_number_of_entries(specified_table_size);
 108
 109        /*
 110         * number of bytes needed for the bitmap size in number of
 111         * entries; we need one bit per entry
 112         */
 113        bitmapsz = tbl->it_size / BITS_PER_BYTE;
 114        bmppages = __get_free_pages(GFP_KERNEL, get_order(bitmapsz));
 115        if (!bmppages) {
 116                printk(KERN_ERR "Calgary: cannot allocate bitmap\n");
 117                ret = -ENOMEM;
 118                goto done;
 119        }
 120
 121        tbl->it_map = (unsigned long*)bmppages;
 122
 123        memset(tbl->it_map, 0, bitmapsz);
 124
 125        tbl->it_hint = 0;
 126
 127        spin_lock_init(&tbl->it_lock);
 128
 129        return 0;
 130
 131done:
 132        return ret;
 133}
 134
 135int __init build_tce_table(struct pci_dev *dev, void __iomem *bbar)
 136{
 137        struct iommu_table *tbl;
 138        int ret;
 139
 140        if (pci_iommu(dev->bus)) {
 141                printk(KERN_ERR "Calgary: dev %p has sysdata->iommu %p\n",
 142                       dev, pci_iommu(dev->bus));
 143                BUG();
 144        }
 145
 146        tbl = kzalloc(sizeof(struct iommu_table), GFP_KERNEL);
 147        if (!tbl) {
 148                printk(KERN_ERR "Calgary: error allocating iommu_table\n");
 149                ret = -ENOMEM;
 150                goto done;
 151        }
 152
 153        ret = tce_table_setparms(dev, tbl);
 154        if (ret)
 155                goto free_tbl;
 156
 157        tbl->bbar = bbar;
 158
 159        set_pci_iommu(dev->bus, tbl);
 160
 161        return 0;
 162
 163free_tbl:
 164        kfree(tbl);
 165done:
 166        return ret;
 167}
 168
 169void * __init alloc_tce_table(void)
 170{
 171        unsigned int size;
 172
 173        size = table_size_to_number_of_entries(specified_table_size);
 174        size *= TCE_ENTRY_SIZE;
 175
 176        return __alloc_bootmem_low(size, size, 0);
 177}
 178
 179void __init free_tce_table(void *tbl)
 180{
 181        unsigned int size;
 182
 183        if (!tbl)
 184                return;
 185
 186        size = table_size_to_number_of_entries(specified_table_size);
 187        size *= TCE_ENTRY_SIZE;
 188
 189        free_bootmem(__pa(tbl), size);
 190}
 191