arch/powerpc/platforms/pasemi/iommu.c

   1 /*
   2  * Copyright (C) 2005-2008, PA Semi, Inc
   3  *
   4  * Maintained by: Olof Johansson <olof@lixom.net>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  18  */
  19
  20 #undef DEBUG
  21
  22 #include <linux/types.h>
  23 #include <linux/spinlock.h>
  24 #include <linux/pci.h>
  25 #include <asm/iommu.h>
  26 #include <asm/machdep.h>
  27 #include <asm/abs_addr.h>
  28 #include <asm/firmware.h>
  29
  30 #define IOBMAP_PAGE_SHIFT       12
  31 #define IOBMAP_PAGE_SIZE        (1 << IOBMAP_PAGE_SHIFT)
  32 #define IOBMAP_PAGE_MASK        (IOBMAP_PAGE_SIZE - 1)
  33
  34 #define IOB_BASE                0xe0000000
  35 #define IOB_SIZE                0x3000
  36 /* Configuration registers */
  37 #define IOBCAP_REG              0x40
  38 #define IOBCOM_REG              0x100
  39 /* Enable IOB address translation */
  40 #define IOBCOM_ATEN             0x00000100
  41
  42 /* Address decode configuration register */
  43 #define IOB_AD_REG              0x14c
  44 /* IOBCOM_AD_REG fields */
  45 #define IOB_AD_VGPRT            0x00000e00
  46 #define IOB_AD_VGAEN            0x00000100
  47 /* Direct mapping settings */
  48 #define IOB_AD_MPSEL_MASK       0x00000030
  49 #define IOB_AD_MPSEL_B38        0x00000000
  50 #define IOB_AD_MPSEL_B40        0x00000010
  51 #define IOB_AD_MPSEL_B42        0x00000020
  52 /* Translation window size / enable */
  53 #define IOB_AD_TRNG_MASK        0x00000003
  54 #define IOB_AD_TRNG_256M        0x00000000
  55 #define IOB_AD_TRNG_2G          0x00000001
  56 #define IOB_AD_TRNG_128G        0x00000003
  57
  58 #define IOB_TABLEBASE_REG       0x154
  59
  60 /* Base of the 64 4-byte L1 registers */
  61 #define IOB_XLT_L1_REGBASE      0x2b00
  62
  63 /* Register to invalidate TLB entries */
  64 #define IOB_AT_INVAL_TLB_REG    0x2d00
  65
  66 /* The top two bits of the level 1 entry contains valid and type flags */
  67 #define IOBMAP_L1E_V            0x40000000
  68 #define IOBMAP_L1E_V_B          0x80000000
  69
  70 /* For big page entries, the bottom two bits contains flags */
  71 #define IOBMAP_L1E_BIG_CACHED   0x00000002
  72 #define IOBMAP_L1E_BIG_PRIORITY 0x00000001
  73
  74 /* For regular level 2 entries, top 2 bits contain valid and cache flags */
  75 #define IOBMAP_L2E_V            0x80000000
  76 #define IOBMAP_L2E_V_CACHED     0xc0000000
  77
  78 static void __iomem *iob;
  79 static u32 iob_l1_emptyval;
  80 static u32 iob_l2_emptyval;
  81 static u32 *iob_l2_base;
  82
  83 static struct iommu_table iommu_table_iobmap;
  84 static int iommu_table_iobmap_inited;
  85
  86 static int iobmap_build(struct iommu_table *tbl, long index,
  87                          long npages, unsigned long uaddr,
  88                          enum dma_data_direction direction,
  89                          struct dma_attrs *attrs)
  90 {
  91         u32 *ip;
  92         u32 rpn;
  93         unsigned long bus_addr;
  94
  95         pr_debug("iobmap: build at: %lx, %lx, addr: %lx\n", index, npages, uaddr);
  96
  97         bus_addr = (tbl->it_offset + index) << IOBMAP_PAGE_SHIFT;
  98
  99         ip = ((u32 *)tbl->it_base) + index;
 100
 101         while (npages--) {
 102                 rpn = virt_to_abs(uaddr) >> IOBMAP_PAGE_SHIFT;
 103
 104                 *(ip++) = IOBMAP_L2E_V | rpn;
 105                 /* invalidate tlb, can be optimized more */
 106                 out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
 107
 108                 uaddr += IOBMAP_PAGE_SIZE;
 109                 bus_addr += IOBMAP_PAGE_SIZE;
 110         }
 111         return 0;
 112 }
 113
 114
 115 static void iobmap_free(struct iommu_table *tbl, long index,
 116                         long npages)
 117 {
 118         u32 *ip;
 119         unsigned long bus_addr;
 120
 121         pr_debug("iobmap: free at: %lx, %lx\n", index, npages);
 122
 123         bus_addr = (tbl->it_offset + index) << IOBMAP_PAGE_SHIFT;
 124
 125         ip = ((u32 *)tbl->it_base) + index;
 126
 127         while (npages--) {
 128                 *(ip++) = iob_l2_emptyval;
 129                 /* invalidate tlb, can be optimized more */
 130                 out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
 131                 bus_addr += IOBMAP_PAGE_SIZE;
 132         }
 133 }
 134
 135
 136 static void iommu_table_iobmap_setup(void)
 137 {
 138         pr_debug(" -> %s\n", __func__);
 139         iommu_table_iobmap.it_busno = 0;
 140         iommu_table_iobmap.it_offset = 0;
 141         /* it_size is in number of entries */
 142         iommu_table_iobmap.it_size = 0x80000000 >> IOBMAP_PAGE_SHIFT;
 143
 144         /* Initialize the common IOMMU code */
 145         iommu_table_iobmap.it_base = (unsigned long)iob_l2_base;
 146         iommu_table_iobmap.it_index = 0;
 147         /* XXXOJN tune this to avoid IOB cache invals.
 148          * Should probably be 8 (64 bytes)
 149          */
 150         iommu_table_iobmap.it_blocksize = 4;
 151         iommu_init_table(&iommu_table_iobmap, 0);
 152         pr_debug(" <- %s\n", __func__);
 153 }
 154
 155
 156
 157 static void pci_dma_bus_setup_pasemi(struct pci_bus *bus)
 158 {
 159         struct device_node *dn;
 160
 161         pr_debug("pci_dma_bus_setup, bus %p, bus->self %p\n", bus, bus->self);
 162
 163         if (!iommu_table_iobmap_inited) {
 164                 iommu_table_iobmap_inited = 1;
 165                 iommu_table_iobmap_setup();
 166         }
 167
 168         dn = pci_bus_to_OF_node(bus);
 169
 170         if (dn)
 171                 PCI_DN(dn)->iommu_table = &iommu_table_iobmap;
 172
 173 }
 174
 175
 176 static void pci_dma_dev_setup_pasemi(struct pci_dev *dev)
 177 {
 178         pr_debug("pci_dma_dev_setup, dev %p (%s)\n", dev, pci_name(dev));
 179
 180 #if !defined(CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE)
 181         /* For non-LPAR environment, don't translate anything for the DMA
 182          * engine. The exception to this is if the user has enabled
 183          * CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE at build time.
 184          */
 185         if (dev->vendor == 0x1959 && dev->device == 0xa007 &&
 186             !firmware_has_feature(FW_FEATURE_LPAR)) {
 187                 dev->dev.archdata.dma_ops = &dma_direct_ops;
 188                 return;
 189         }
 190 #endif
 191
 192         dev->dev.archdata.dma_data = &iommu_table_iobmap;
 193 }
 194
 195 static void pci_dma_bus_setup_null(struct pci_bus *b) { }
 196 static void pci_dma_dev_setup_null(struct pci_dev *d) { }
 197
 198 int __init iob_init(struct device_node *dn)
 199 {
 200         unsigned long tmp;
 201         u32 regword;
 202         int i;
 203
 204         pr_debug(" -> %s\n", __func__);
 205
 206         /* Allocate a spare page to map all invalid IOTLB pages. */
 207         tmp = lmb_alloc(IOBMAP_PAGE_SIZE, IOBMAP_PAGE_SIZE);
 208         if (!tmp)
 209                 panic("IOBMAP: Cannot allocate spare page!");
 210         /* Empty l1 is marked invalid */
 211         iob_l1_emptyval = 0;
 212         /* Empty l2 is mapped to dummy page */
 213         iob_l2_emptyval = IOBMAP_L2E_V | (tmp >> IOBMAP_PAGE_SHIFT);
 214
 215         iob = ioremap(IOB_BASE, IOB_SIZE);
 216         if (!iob)
 217                 panic("IOBMAP: Cannot map registers!");
 218
 219         /* setup direct mapping of the L1 entries */
 220         for (i = 0; i < 64; i++) {
 221                 /* Each L1 covers 32MB, i.e. 8K entries = 32K of ram */
 222                 regword = IOBMAP_L1E_V | (__pa(iob_l2_base + i*0x2000) >> 12);
 223                 out_le32(iob+IOB_XLT_L1_REGBASE+i*4, regword);
 224         }
 225
 226         /* set 2GB translation window, based at 0 */
 227         regword = in_le32(iob+IOB_AD_REG);
 228         regword &= ~IOB_AD_TRNG_MASK;
 229         regword |= IOB_AD_TRNG_2G;
 230         out_le32(iob+IOB_AD_REG, regword);
 231
 232         /* Enable translation */
 233         regword = in_le32(iob+IOBCOM_REG);
 234         regword |= IOBCOM_ATEN;
 235         out_le32(iob+IOBCOM_REG, regword);
 236
 237         pr_debug(" <- %s\n", __func__);
 238
 239         return 0;
 240 }
 241
 242
 243 /* These are called very early. */
 244 void __init iommu_init_early_pasemi(void)
 245 {
 246         int iommu_off;
 247
 248 #ifndef CONFIG_PPC_PASEMI_IOMMU
 249         iommu_off = 1;
 250 #else
 251         iommu_off = of_chosen &&
 252                         of_get_property(of_chosen, "linux,iommu-off", NULL);
 253 #endif
 254         if (iommu_off) {
 255                 /* Direct I/O, IOMMU off */
 256                 ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_null;
 257                 ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_null;
 258                 set_pci_dma_ops(&dma_direct_ops);
 259
 260                 return;
 261         }
 262
 263         iob_init(NULL);
 264
 265         ppc_md.pci_dma_dev_setup = pci_dma_dev_setup_pasemi;
 266         ppc_md.pci_dma_bus_setup = pci_dma_bus_setup_pasemi;
 267         ppc_md.tce_build = iobmap_build;
 268         ppc_md.tce_free  = iobmap_free;
 269         set_pci_dma_ops(&dma_iommu_ops);
 270 }
 271
 272 void __init alloc_iobmap_l2(void)
 273 {
 274 #ifndef CONFIG_PPC_PASEMI_IOMMU
 275         return;
 276 #endif
 277         /* For 2G space, 8x64 pages (2^21 bytes) is max total l2 size */
 278         iob_l2_base = (u32 *)abs_to_virt(lmb_alloc_base(1UL<<21, 1UL<<21, 0x80000000));
 279
 280         printk(KERN_INFO "IOBMAP L2 allocated at: %p\n", iob_l2_base);
 281 }