arch/powerpc/platforms/iseries/iommu.c

   1 /*
   2  * Copyright (C) 2001 Mike Corrigan & Dave Engebretsen, IBM Corporation
   3  *
   4  * Rewrite, cleanup:
   5  *
   6  * Copyright (C) 2004 Olof Johansson <olof@lixom.net>, IBM Corporation
   7  * Copyright (C) 2006 Olof Johansson <olof@lixom.net>
   8  *
   9  * Dynamic DMA mapping support, iSeries-specific parts.
  10  *
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  25  */
  26
  27 #include <linux/types.h>
  28 #include <linux/dma-mapping.h>
  29 #include <linux/list.h>
  30 #include <linux/pci.h>
  31
  32 #include <asm/iommu.h>
  33 #include <asm/tce.h>
  34 #include <asm/machdep.h>
  35 #include <asm/abs_addr.h>
  36 #include <asm/prom.h>
  37 #include <asm/pci-bridge.h>
  38 #include <asm/iseries/hv_call_xm.h>
  39 #include <asm/iseries/iommu.h>
  40
  41 static void tce_build_iSeries(struct iommu_table *tbl, long index, long npages,
  42                 unsigned long uaddr, enum dma_data_direction direction)
  43 {
  44         u64 rc;
  45         u64 tce, rpn;
  46
  47         while (npages--) {
  48                 rpn = virt_to_abs(uaddr) >> TCE_SHIFT;
  49                 tce = (rpn & TCE_RPN_MASK) << TCE_RPN_SHIFT;
  50
  51                 if (tbl->it_type == TCE_VB) {
  52                         /* Virtual Bus */
  53                         tce |= TCE_VALID|TCE_ALLIO;
  54                         if (direction != DMA_TO_DEVICE)
  55                                 tce |= TCE_VB_WRITE;
  56                 } else {
  57                         /* PCI Bus */
  58                         tce |= TCE_PCI_READ; /* Read allowed */
  59                         if (direction != DMA_TO_DEVICE)
  60                                 tce |= TCE_PCI_WRITE;
  61                 }
  62
  63                 rc = HvCallXm_setTce((u64)tbl->it_index, (u64)index, tce);
  64                 if (rc)
  65                         panic("PCI_DMA: HvCallXm_setTce failed, Rc: 0x%lx\n",
  66                                         rc);
  67                 index++;
  68                 uaddr += TCE_PAGE_SIZE;
  69         }
  70 }
  71
  72 static void tce_free_iSeries(struct iommu_table *tbl, long index, long npages)
  73 {
  74         u64 rc;
  75
  76         while (npages--) {
  77                 rc = HvCallXm_setTce((u64)tbl->it_index, (u64)index, 0);
  78                 if (rc)
  79                         panic("PCI_DMA: HvCallXm_setTce failed, Rc: 0x%lx\n",
  80                                         rc);
  81                 index++;
  82         }
  83 }
  84
  85 /*
  86  * Structure passed to HvCallXm_getTceTableParms
  87  */
  88 struct iommu_table_cb {
  89         unsigned long   itc_busno;      /* Bus number for this tce table */
  90         unsigned long   itc_start;      /* Will be NULL for secondary */
  91         unsigned long   itc_totalsize;  /* Size (in pages) of whole table */
  92         unsigned long   itc_offset;     /* Index into real tce table of the
  93                                            start of our section */
  94         unsigned long   itc_size;       /* Size (in pages) of our section */
  95         unsigned long   itc_index;      /* Index of this tce table */
  96         unsigned short  itc_maxtables;  /* Max num of tables for partition */
  97         unsigned char   itc_virtbus;    /* Flag to indicate virtual bus */
  98         unsigned char   itc_slotno;     /* IOA Tce Slot Index */
  99         unsigned char   itc_rsvd[4];
 100 };
 101
 102 /*
 103  * Call Hv with the architected data structure to get TCE table info.
 104  * info. Put the returned data into the Linux representation of the
 105  * TCE table data.
 106  * The Hardware Tce table comes in three flavors.
 107  * 1. TCE table shared between Buses.
 108  * 2. TCE table per Bus.
 109  * 3. TCE Table per IOA.
 110  */
 111 void iommu_table_getparms_iSeries(unsigned long busno,
 112                                   unsigned char slotno,
 113                                   unsigned char virtbus,
 114                                   struct iommu_table* tbl)
 115 {
 116         struct iommu_table_cb *parms;
 117
 118         parms = kzalloc(sizeof(*parms), GFP_KERNEL);
 119         if (parms == NULL)
 120                 panic("PCI_DMA: TCE Table Allocation failed.");
 121
 122         parms->itc_busno = busno;
 123         parms->itc_slotno = slotno;
 124         parms->itc_virtbus = virtbus;
 125
 126         HvCallXm_getTceTableParms(iseries_hv_addr(parms));
 127
 128         if (parms->itc_size == 0)
 129                 panic("PCI_DMA: parms->size is zero, parms is 0x%p", parms);
 130
 131         /* itc_size is in pages worth of table, it_size is in # of entries */
 132         tbl->it_size = (parms->itc_size * TCE_PAGE_SIZE) / TCE_ENTRY_SIZE;
 133         tbl->it_busno = parms->itc_busno;
 134         tbl->it_offset = parms->itc_offset;
 135         tbl->it_index = parms->itc_index;
 136         tbl->it_blocksize = 1;
 137         tbl->it_type = virtbus ? TCE_VB : TCE_PCI;
 138
 139         kfree(parms);
 140 }
 141
 142
 143 #ifdef CONFIG_PCI
 144 /*
 145  * This function compares the known tables to find an iommu_table
 146  * that has already been built for hardware TCEs.
 147  */
 148 static struct iommu_table *iommu_table_find(struct iommu_table * tbl)
 149 {
 150         struct device_node *node;
 151
 152         for (node = NULL; (node = of_find_all_nodes(node)); ) {
 153                 struct pci_dn *pdn = PCI_DN(node);
 154                 struct iommu_table *it;
 155
 156                 if (pdn == NULL)
 157                         continue;
 158                 it = pdn->iommu_table;
 159                 if ((it != NULL) &&
 160                     (it->it_type == TCE_PCI) &&
 161                     (it->it_offset == tbl->it_offset) &&
 162                     (it->it_index == tbl->it_index) &&
 163                     (it->it_size == tbl->it_size))
 164                         return it;
 165         }
 166         return NULL;
 167 }
 168
 169
 170 void iommu_devnode_init_iSeries(struct pci_dev *pdev, struct device_node *dn)
 171 {
 172         struct iommu_table *tbl;
 173         struct pci_dn *pdn = PCI_DN(dn);
 174         const u32 *lsn = get_property(dn, "linux,logical-slot-number", NULL);
 175
 176         BUG_ON(lsn == NULL);
 177
 178         tbl = kmalloc(sizeof(struct iommu_table), GFP_KERNEL);
 179
 180         iommu_table_getparms_iSeries(pdn->busno, *lsn, 0, tbl);
 181
 182         /* Look for existing tce table */
 183         pdn->iommu_table = iommu_table_find(tbl);
 184         if (pdn->iommu_table == NULL)
 185                 pdn->iommu_table = iommu_init_table(tbl, -1);
 186         else
 187                 kfree(tbl);
 188         pdev->dev.archdata.dma_data = pdn->iommu_table;
 189 }
 190 #endif
 191
 192 void iommu_init_early_iSeries(void)
 193 {
 194         ppc_md.tce_build = tce_build_iSeries;
 195         ppc_md.tce_free  = tce_free_iSeries;
 196
 197         pci_dma_ops = &dma_iommu_ops;
 198 }