arch/x86_64/kernel/tce.c

   1 /*
   2  * Derived from arch/powerpc/platforms/pseries/iommu.c
   3  *
   4  * Copyright (C) 2006 Jon Mason <jdmason@us.ibm.com>, IBM Corporation
   5  * Copyright (C) 2006 Muli Ben-Yehuda <muli@il.ibm.com>, IBM Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  */
  21
  22 #include <linux/config.h>
  23 #include <linux/types.h>
  24 #include <linux/slab.h>
  25 #include <linux/mm.h>
  26 #include <linux/spinlock.h>
  27 #include <linux/string.h>
  28 #include <linux/pci.h>
  29 #include <linux/dma-mapping.h>
  30 #include <linux/bootmem.h>
  31 #include <asm/tce.h>
  32 #include <asm/calgary.h>
  33 #include <asm/proto.h>
  34
  35 /* flush a tce at 'tceaddr' to main memory */
  36 static inline void flush_tce(void* tceaddr)
  37 {
  38         /* a single tce can't cross a cache line */
  39         if (cpu_has_clflush)
  40                 asm volatile("clflush (%0)" :: "r" (tceaddr));
  41         else
  42                 asm volatile("wbinvd":::"memory");
  43 }
  44
  45 void tce_build(struct iommu_table *tbl, unsigned long index,
  46         unsigned int npages, unsigned long uaddr, int direction)
  47 {
  48         u64* tp;
  49         u64 t;
  50         u64 rpn;
  51
  52         t = (1 << TCE_READ_SHIFT);
  53         if (direction != DMA_TO_DEVICE)
  54                 t |= (1 << TCE_WRITE_SHIFT);
  55
  56         tp = ((u64*)tbl->it_base) + index;
  57
  58         while (npages--) {
  59                 rpn = (virt_to_bus((void*)uaddr)) >> PAGE_SHIFT;
  60                 t &= ~TCE_RPN_MASK;
  61                 t |= (rpn << TCE_RPN_SHIFT);
  62
  63                 *tp = cpu_to_be64(t);
  64                 flush_tce(tp);
  65
  66                 uaddr += PAGE_SIZE;
  67                 tp++;
  68         }
  69 }
  70
  71 void tce_free(struct iommu_table *tbl, long index, unsigned int npages)
  72 {
  73         u64* tp;
  74
  75         tp  = ((u64*)tbl->it_base) + index;
  76
  77         while (npages--) {
  78                 *tp = cpu_to_be64(0);
  79                 flush_tce(tp);
  80                 tp++;
  81         }
  82 }
  83
  84 static inline unsigned int table_size_to_number_of_entries(unsigned char size)
  85 {
  86         /*
  87          * size is the order of the table, 0-7
  88          * smallest table is 8K entries, so shift result by 13 to
  89          * multiply by 8K
  90          */
  91         return (1 << size) << 13;
  92 }
  93
  94 static int tce_table_setparms(struct pci_dev *dev, struct iommu_table *tbl)
  95 {
  96         unsigned int bitmapsz;
  97         unsigned int tce_table_index;
  98         unsigned long bmppages;
  99         int ret;
 100
 101         tbl->it_busno = dev->bus->number;
 102
 103         /* set the tce table size - measured in entries */
 104         tbl->it_size = table_size_to_number_of_entries(specified_table_size);
 105
 106         tce_table_index = bus_to_phb(tbl->it_busno);
 107         tbl->it_base = (unsigned long)tce_table_kva[tce_table_index];
 108         if (!tbl->it_base) {
 109                 printk(KERN_ERR "Calgary: iommu_table_setparms: "
 110                        "no table allocated?!\n");
 111                 ret = -ENOMEM;
 112                 goto done;
 113         }
 114
 115         /*
 116          * number of bytes needed for the bitmap size in number of
 117          * entries; we need one bit per entry
 118          */
 119         bitmapsz = tbl->it_size / BITS_PER_BYTE;
 120         bmppages = __get_free_pages(GFP_KERNEL, get_order(bitmapsz));
 121         if (!bmppages) {
 122                 printk(KERN_ERR "Calgary: cannot allocate bitmap\n");
 123                 ret = -ENOMEM;
 124                 goto done;
 125         }
 126
 127         tbl->it_map = (unsigned long*)bmppages;
 128
 129         memset(tbl->it_map, 0, bitmapsz);
 130
 131         tbl->it_hint = 0;
 132
 133         spin_lock_init(&tbl->it_lock);
 134
 135         return 0;
 136
 137 done:
 138         return ret;
 139 }
 140
 141 int build_tce_table(struct pci_dev *dev, void __iomem *bbar)
 142 {
 143         struct iommu_table *tbl;
 144         int ret;
 145
 146         if (dev->sysdata) {
 147                 printk(KERN_ERR "Calgary: dev %p has sysdata %p\n",
 148                        dev, dev->sysdata);
 149                 BUG();
 150         }
 151
 152         tbl = kzalloc(sizeof(struct iommu_table), GFP_KERNEL);
 153         if (!tbl) {
 154                 printk(KERN_ERR "Calgary: error allocating iommu_table\n");
 155                 ret = -ENOMEM;
 156                 goto done;
 157         }
 158
 159         ret = tce_table_setparms(dev, tbl);
 160         if (ret)
 161                 goto free_tbl;
 162
 163         tce_free(tbl, 0, tbl->it_size);
 164
 165         tbl->bbar = bbar;
 166
 167         /*
 168          * NUMA is already using the bus's sysdata pointer, so we use
 169          * the bus's pci_dev's sysdata instead.
 170          */
 171         dev->sysdata = tbl;
 172
 173         return 0;
 174
 175 free_tbl:
 176         kfree(tbl);
 177 done:
 178         return ret;
 179 }
 180
 181 void* alloc_tce_table(void)
 182 {
 183         unsigned int size;
 184
 185         size = table_size_to_number_of_entries(specified_table_size);
 186         size *= TCE_ENTRY_SIZE;
 187
 188         return __alloc_bootmem_low(size, size, 0);
 189 }
 190
 191 void free_tce_table(void *tbl)
 192 {
 193         unsigned int size;
 194
 195         if (!tbl)
 196                 return;
 197
 198         size = table_size_to_number_of_entries(specified_table_size);
 199         size *= TCE_ENTRY_SIZE;
 200
 201         free_bootmem(__pa(tbl), size);
 202 }