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
  38/* flush a tce at 'tceaddr' to main memory */
  39static inline void flush_tce(void* tceaddr)
  40{
  41        /* a single tce can't cross a cache line */
  42        if (cpu_has_clflush)
  43                clflush(tceaddr);
  44        else
  45                wbinvd();
  46}
  47
  48void tce_build(struct iommu_table *tbl, unsigned long index,
  49        unsigned int npages, unsigned long uaddr, int direction)
  50{
  51        u64* tp;
  52        u64 t;
  53        u64 rpn;
  54
  55        t = (1 << TCE_READ_SHIFT);
  56        if (direction != DMA_TO_DEVICE)
  57                t |= (1 << TCE_WRITE_SHIFT);
  58
  59        tp = ((u64*)tbl->it_base) + index;
  60
  61        while (npages--) {
  62                rpn = (virt_to_bus((void*)uaddr)) >> PAGE_SHIFT;
  63                t &= ~TCE_RPN_MASK;
  64                t |= (rpn << TCE_RPN_SHIFT);
  65
  66                *tp = cpu_to_be64(t);
  67                flush_tce(tp);
  68
  69                uaddr += PAGE_SIZE;
  70                tp++;
  71        }
  72}
  73
  74void tce_free(struct iommu_table *tbl, long index, unsigned int npages)
  75{
  76        u64* tp;
  77
  78        tp  = ((u64*)tbl->it_base) + index;
  79
  80        while (npages--) {
  81                *tp = cpu_to_be64(0);
  82                flush_tce(tp);
  83                tp++;
  84        }
  85}
  86
  87static inline unsigned int table_size_to_number_of_entries(unsigned char size)
  88{
  89        /*
  90         * size is the order of the table, 0-7
  91         * smallest table is 8K entries, so shift result by 13 to
  92         * multiply by 8K
  93         */
  94        return (1 << size) << 13;
  95}
  96
  97static int tce_table_setparms(struct pci_dev *dev, struct iommu_table *tbl)
  98{
  99        unsigned int bitmapsz;
 100        unsigned long bmppages;
 101        int ret;
 102
 103        tbl->it_busno = dev->bus->number;
 104
 105        /* set the tce table size - measured in entries */
 106        tbl->it_size = table_size_to_number_of_entries(specified_table_size);
 107
 108        /*
 109         * number of bytes needed for the bitmap size in number of
 110         * entries; we need one bit per entry
 111         */
 112        bitmapsz = tbl->it_size / BITS_PER_BYTE;
 113        bmppages = __get_free_pages(GFP_KERNEL, get_order(bitmapsz));
 114        if (!bmppages) {
 115                printk(KERN_ERR "Calgary: cannot allocate bitmap\n");
 116                ret = -ENOMEM;
 117                goto done;
 118        }
 119
 120        tbl->it_map = (unsigned long*)bmppages;
 121
 122        memset(tbl->it_map, 0, bitmapsz);
 123
 124        tbl->it_hint = 0;
 125
 126        spin_lock_init(&tbl->it_lock);
 127
 128        return 0;
 129
 130done:
 131        return ret;
 132}
 133
 134int __init build_tce_table(struct pci_dev *dev, void __iomem *bbar)
 135{
 136        struct iommu_table *tbl;
 137        int ret;
 138
 139        if (pci_iommu(dev->bus)) {
 140                printk(KERN_ERR "Calgary: dev %p has sysdata->iommu %p\n",
 141                       dev, pci_iommu(dev->bus));
 142                BUG();
 143        }
 144
 145        tbl = kzalloc(sizeof(struct iommu_table), GFP_KERNEL);
 146        if (!tbl) {
 147                printk(KERN_ERR "Calgary: error allocating iommu_table\n");
 148                ret = -ENOMEM;
 149                goto done;
 150        }
 151
 152        ret = tce_table_setparms(dev, tbl);
 153        if (ret)
 154                goto free_tbl;
 155
 156        tbl->bbar = bbar;
 157
 158        set_pci_iommu(dev->bus, tbl);
 159
 160        return 0;
 161
 162free_tbl:
 163        kfree(tbl);
 164done:
 165        return ret;
 166}
 167
 168void * __init alloc_tce_table(void)
 169{
 170        unsigned int size;
 171
 172        size = table_size_to_number_of_entries(specified_table_size);
 173        size *= TCE_ENTRY_SIZE;
 174
 175        return __alloc_bootmem_low(size, size, 0);
 176}
 177
 178void __init free_tce_table(void *tbl)
 179{
 180        unsigned int size;
 181
 182        if (!tbl)
 183                return;
 184
 185        size = table_size_to_number_of_entries(specified_table_size);
 186        size *= TCE_ENTRY_SIZE;
 187
 188        free_bootmem(__pa(tbl), size);
 189}
 190