root/arch/powerpc/platforms/pasemi/iommu.c

DEFINITIONS

1. iobmap_build
2. iobmap_free
3. iommu_table_iobmap_setup
4. pci_dma_bus_setup_pasemi
5. pci_dma_dev_setup_pasemi
6. iob_init
7. iommu_init_early_pasemi

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2005-2008, PA Semi, Inc
   4  *
   5  * Maintained by: Olof Johansson <olof@lixom.net>
   6  */
   7 
   8 #undef DEBUG
   9 
  10 #include <linux/memblock.h>
  11 #include <linux/types.h>
  12 #include <linux/spinlock.h>
  13 #include <linux/pci.h>
  14 #include <asm/iommu.h>
  15 #include <asm/machdep.h>
  16 #include <asm/firmware.h>
  17 
  18 #include "pasemi.h"
  19 
  20 #define IOBMAP_PAGE_SHIFT       12
  21 #define IOBMAP_PAGE_SIZE        (1 << IOBMAP_PAGE_SHIFT)
  22 #define IOBMAP_PAGE_MASK        (IOBMAP_PAGE_SIZE - 1)
  23 
  24 #define IOB_BASE                0xe0000000
  25 #define IOB_SIZE                0x3000
  26 /* Configuration registers */
  27 #define IOBCAP_REG              0x40
  28 #define IOBCOM_REG              0x100
  29 /* Enable IOB address translation */
  30 #define IOBCOM_ATEN             0x00000100
  31 
  32 /* Address decode configuration register */
  33 #define IOB_AD_REG              0x14c
  34 /* IOBCOM_AD_REG fields */
  35 #define IOB_AD_VGPRT            0x00000e00
  36 #define IOB_AD_VGAEN            0x00000100
  37 /* Direct mapping settings */
  38 #define IOB_AD_MPSEL_MASK       0x00000030
  39 #define IOB_AD_MPSEL_B38        0x00000000
  40 #define IOB_AD_MPSEL_B40        0x00000010
  41 #define IOB_AD_MPSEL_B42        0x00000020
  42 /* Translation window size / enable */
  43 #define IOB_AD_TRNG_MASK        0x00000003
  44 #define IOB_AD_TRNG_256M        0x00000000
  45 #define IOB_AD_TRNG_2G          0x00000001
  46 #define IOB_AD_TRNG_128G        0x00000003
  47 
  48 #define IOB_TABLEBASE_REG       0x154
  49 
  50 /* Base of the 64 4-byte L1 registers */
  51 #define IOB_XLT_L1_REGBASE      0x2b00
  52 
  53 /* Register to invalidate TLB entries */
  54 #define IOB_AT_INVAL_TLB_REG    0x2d00
  55 
  56 /* The top two bits of the level 1 entry contains valid and type flags */
  57 #define IOBMAP_L1E_V            0x40000000
  58 #define IOBMAP_L1E_V_B          0x80000000
  59 
  60 /* For big page entries, the bottom two bits contains flags */
  61 #define IOBMAP_L1E_BIG_CACHED   0x00000002
  62 #define IOBMAP_L1E_BIG_PRIORITY 0x00000001
  63 
  64 /* For regular level 2 entries, top 2 bits contain valid and cache flags */
  65 #define IOBMAP_L2E_V            0x80000000
  66 #define IOBMAP_L2E_V_CACHED     0xc0000000
  67 
  68 static void __iomem *iob;
  69 static u32 iob_l1_emptyval;
  70 static u32 iob_l2_emptyval;
  71 static u32 *iob_l2_base;
  72 
  73 static struct iommu_table iommu_table_iobmap;
  74 static int iommu_table_iobmap_inited;
  75 
  76 static int iobmap_build(struct iommu_table *tbl, long index,
  77                          long npages, unsigned long uaddr,
  78                          enum dma_data_direction direction,
  79                          unsigned long attrs)
  80 {
  81         u32 *ip;
  82         u32 rpn;
  83         unsigned long bus_addr;
  84 
  85         pr_debug("iobmap: build at: %lx, %lx, addr: %lx\n", index, npages, uaddr);
  86 
  87         bus_addr = (tbl->it_offset + index) << IOBMAP_PAGE_SHIFT;
  88 
  89         ip = ((u32 *)tbl->it_base) + index;
  90 
  91         while (npages--) {
  92                 rpn = __pa(uaddr) >> IOBMAP_PAGE_SHIFT;
  93 
  94                 *(ip++) = IOBMAP_L2E_V | rpn;
  95                 /* invalidate tlb, can be optimized more */
  96                 out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
  97 
  98                 uaddr += IOBMAP_PAGE_SIZE;
  99                 bus_addr += IOBMAP_PAGE_SIZE;
 100         }
 101         return 0;
 102 }
 103 
 104 
 105 static void iobmap_free(struct iommu_table *tbl, long index,
 106                         long npages)
 107 {
 108         u32 *ip;
 109         unsigned long bus_addr;
 110 
 111         pr_debug("iobmap: free at: %lx, %lx\n", index, npages);
 112 
 113         bus_addr = (tbl->it_offset + index) << IOBMAP_PAGE_SHIFT;
 114 
 115         ip = ((u32 *)tbl->it_base) + index;
 116 
 117         while (npages--) {
 118                 *(ip++) = iob_l2_emptyval;
 119                 /* invalidate tlb, can be optimized more */
 120                 out_le32(iob+IOB_AT_INVAL_TLB_REG, bus_addr >> 14);
 121                 bus_addr += IOBMAP_PAGE_SIZE;
 122         }
 123 }
 124 
 125 static struct iommu_table_ops iommu_table_iobmap_ops = {
 126         .set = iobmap_build,
 127         .clear  = iobmap_free
 128 };
 129 
 130 static void iommu_table_iobmap_setup(void)
 131 {
 132         pr_debug(" -> %s\n", __func__);
 133         iommu_table_iobmap.it_busno = 0;
 134         iommu_table_iobmap.it_offset = 0;
 135         iommu_table_iobmap.it_page_shift = IOBMAP_PAGE_SHIFT;
 136 
 137         /* it_size is in number of entries */
 138         iommu_table_iobmap.it_size =
 139                 0x80000000 >> iommu_table_iobmap.it_page_shift;
 140 
 141         /* Initialize the common IOMMU code */
 142         iommu_table_iobmap.it_base = (unsigned long)iob_l2_base;
 143         iommu_table_iobmap.it_index = 0;
 144         /* XXXOJN tune this to avoid IOB cache invals.
 145          * Should probably be 8 (64 bytes)
 146          */
 147         iommu_table_iobmap.it_blocksize = 4;
 148         iommu_table_iobmap.it_ops = &iommu_table_iobmap_ops;
 149         iommu_init_table(&iommu_table_iobmap, 0, 0, 0);
 150         pr_debug(" <- %s\n", __func__);
 151 }
 152 
 153 
 154 
 155 static void pci_dma_bus_setup_pasemi(struct pci_bus *bus)
 156 {
 157         pr_debug("pci_dma_bus_setup, bus %p, bus->self %p\n", bus, bus->self);
 158 
 159         if (!iommu_table_iobmap_inited) {
 160                 iommu_table_iobmap_inited = 1;
 161                 iommu_table_iobmap_setup();
 162         }
 163 }
 164 
 165 
 166 static void pci_dma_dev_setup_pasemi(struct pci_dev *dev)
 167 {
 168         pr_debug("pci_dma_dev_setup, dev %p (%s)\n", dev, pci_name(dev));
 169 
 170 #if !defined(CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE)
 171         /* For non-LPAR environment, don't translate anything for the DMA
 172          * engine. The exception to this is if the user has enabled
 173          * CONFIG_PPC_PASEMI_IOMMU_DMA_FORCE at build time.
 174          */
 175         if (dev->vendor == 0x1959 && dev->device == 0xa007 &&
 176             !firmware_has_feature(FW_FEATURE_LPAR)) {
 177                 dev->dev.dma_ops = NULL;
 178                 /*
 179                  * Set the coherent DMA mask to prevent the iommu
 180                  * being used unnecessarily
 181                  */
 182                 dev->dev.coherent_dma_mask = DMA_BIT_MASK(44);
 183                 return;
 184         }
 185 #endif
 186 
 187         set_iommu_table_base(&dev->dev, &iommu_table_iobmap);
 188 }
 189 
 190 static int __init iob_init(struct device_node *dn)
 191 {
 192         unsigned long tmp;
 193         u32 regword;
 194         int i;
 195 
 196         pr_debug(" -> %s\n", __func__);
 197 
 198         /* For 2G space, 8x64 pages (2^21 bytes) is max total l2 size */
 199         iob_l2_base = memblock_alloc_try_nid_raw(1UL << 21, 1UL << 21,
 200                                         MEMBLOCK_LOW_LIMIT, 0x80000000,
 201                                         NUMA_NO_NODE);
 202         if (!iob_l2_base)
 203                 panic("%s: Failed to allocate %lu bytes align=0x%lx max_addr=%x\n",
 204                       __func__, 1UL << 21, 1UL << 21, 0x80000000);
 205 
 206         pr_info("IOBMAP L2 allocated at: %p\n", iob_l2_base);
 207 
 208         /* Allocate a spare page to map all invalid IOTLB pages. */
 209         tmp = memblock_phys_alloc(IOBMAP_PAGE_SIZE, IOBMAP_PAGE_SIZE);
 210         if (!tmp)
 211                 panic("IOBMAP: Cannot allocate spare page!");
 212         /* Empty l1 is marked invalid */
 213         iob_l1_emptyval = 0;
 214         /* Empty l2 is mapped to dummy page */
 215         iob_l2_emptyval = IOBMAP_L2E_V | (tmp >> IOBMAP_PAGE_SHIFT);
 216 
 217         iob = ioremap(IOB_BASE, IOB_SIZE);
 218         if (!iob)
 219                 panic("IOBMAP: Cannot map registers!");
 220 
 221         /* setup direct mapping of the L1 entries */
 222         for (i = 0; i < 64; i++) {
 223                 /* Each L1 covers 32MB, i.e. 8K entries = 32K of ram */
 224                 regword = IOBMAP_L1E_V | (__pa(iob_l2_base + i*0x2000) >> 12);
 225                 out_le32(iob+IOB_XLT_L1_REGBASE+i*4, regword);
 226         }
 227 
 228         /* set 2GB translation window, based at 0 */
 229         regword = in_le32(iob+IOB_AD_REG);
 230         regword &= ~IOB_AD_TRNG_MASK;
 231         regword |= IOB_AD_TRNG_2G;
 232         out_le32(iob+IOB_AD_REG, regword);
 233 
 234         /* Enable translation */
 235         regword = in_le32(iob+IOBCOM_REG);
 236         regword |= IOBCOM_ATEN;
 237         out_le32(iob+IOBCOM_REG, regword);
 238 
 239         pr_debug(" <- %s\n", __func__);
 240 
 241         return 0;
 242 }
 243 
 244 
 245 /* These are called very early. */
 246 void __init iommu_init_early_pasemi(void)
 247 {
 248         int iommu_off;
 249 
 250 #ifndef CONFIG_PPC_PASEMI_IOMMU
 251         iommu_off = 1;
 252 #else
 253         iommu_off = of_chosen &&
 254                         of_get_property(of_chosen, "linux,iommu-off", NULL);
 255 #endif
 256         if (iommu_off)
 257                 return;
 258 
 259         iob_init(NULL);
 260 
 261         pasemi_pci_controller_ops.dma_dev_setup = pci_dma_dev_setup_pasemi;
 262         pasemi_pci_controller_ops.dma_bus_setup = pci_dma_bus_setup_pasemi;
 263         set_pci_dma_ops(&dma_iommu_ops);
 264 }