arch/arm/mach-omap2/iommu2.c

   1 /*
   2  * omap iommu: omap2/3 architecture specific functions
   3  *
   4  * Copyright (C) 2008-2009 Nokia Corporation
   5  *
   6  * Written by Hiroshi DOYU <Hiroshi.DOYU@nokia.com>,
   7  *              Paul Mundt and Toshihiro Kobayashi
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  */
  13
  14 #include <linux/err.h>
  15 #include <linux/device.h>
  16 #include <linux/jiffies.h>
  17 #include <linux/module.h>
  18 #include <linux/slab.h>
  19 #include <linux/stringify.h>
  20
  21 #include <plat/iommu.h>
  22
  23 /*
  24  * omap2 architecture specific register bit definitions
  25  */
  26 #define IOMMU_ARCH_VERSION      0x00000011
  27
  28 /* SYSCONF */
  29 #define MMU_SYS_IDLE_SHIFT      3
  30 #define MMU_SYS_IDLE_FORCE      (0 << MMU_SYS_IDLE_SHIFT)
  31 #define MMU_SYS_IDLE_NONE       (1 << MMU_SYS_IDLE_SHIFT)
  32 #define MMU_SYS_IDLE_SMART      (2 << MMU_SYS_IDLE_SHIFT)
  33 #define MMU_SYS_IDLE_MASK       (3 << MMU_SYS_IDLE_SHIFT)
  34
  35 #define MMU_SYS_SOFTRESET       (1 << 1)
  36 #define MMU_SYS_AUTOIDLE        1
  37
  38 /* SYSSTATUS */
  39 #define MMU_SYS_RESETDONE       1
  40
  41 /* IRQSTATUS & IRQENABLE */
  42 #define MMU_IRQ_MULTIHITFAULT   (1 << 4)
  43 #define MMU_IRQ_TABLEWALKFAULT  (1 << 3)
  44 #define MMU_IRQ_EMUMISS         (1 << 2)
  45 #define MMU_IRQ_TRANSLATIONFAULT        (1 << 1)
  46 #define MMU_IRQ_TLBMISS         (1 << 0)
  47
  48 #define __MMU_IRQ_FAULT         \
  49         (MMU_IRQ_MULTIHITFAULT | MMU_IRQ_EMUMISS | MMU_IRQ_TRANSLATIONFAULT)
  50 #define MMU_IRQ_MASK            \
  51         (__MMU_IRQ_FAULT | MMU_IRQ_TABLEWALKFAULT | MMU_IRQ_TLBMISS)
  52 #define MMU_IRQ_TWL_MASK        (__MMU_IRQ_FAULT | MMU_IRQ_TABLEWALKFAULT)
  53 #define MMU_IRQ_TLB_MISS_MASK   (__MMU_IRQ_FAULT | MMU_IRQ_TLBMISS)
  54
  55 /* MMU_CNTL */
  56 #define MMU_CNTL_SHIFT          1
  57 #define MMU_CNTL_MASK           (7 << MMU_CNTL_SHIFT)
  58 #define MMU_CNTL_EML_TLB        (1 << 3)
  59 #define MMU_CNTL_TWL_EN         (1 << 2)
  60 #define MMU_CNTL_MMU_EN         (1 << 1)
  61
  62 #define get_cam_va_mask(pgsz)                           \
  63         (((pgsz) == MMU_CAM_PGSZ_16M) ? 0xff000000 :    \
  64          ((pgsz) == MMU_CAM_PGSZ_1M)  ? 0xfff00000 :    \
  65          ((pgsz) == MMU_CAM_PGSZ_64K) ? 0xffff0000 :    \
  66          ((pgsz) == MMU_CAM_PGSZ_4K)  ? 0xfffff000 : 0)
  67
  68
  69 static void __iommu_set_twl(struct iommu *obj, bool on)
  70 {
  71         u32 l = iommu_read_reg(obj, MMU_CNTL);
  72
  73         if (on)
  74                 iommu_write_reg(obj, MMU_IRQ_TWL_MASK, MMU_IRQENABLE);
  75         else
  76                 iommu_write_reg(obj, MMU_IRQ_TLB_MISS_MASK, MMU_IRQENABLE);
  77
  78         l &= ~MMU_CNTL_MASK;
  79         if (on)
  80                 l |= (MMU_CNTL_MMU_EN | MMU_CNTL_TWL_EN);
  81         else
  82                 l |= (MMU_CNTL_MMU_EN);
  83
  84         iommu_write_reg(obj, l, MMU_CNTL);
  85 }
  86
  87
  88 static int omap2_iommu_enable(struct iommu *obj)
  89 {
  90         u32 l, pa;
  91         unsigned long timeout;
  92
  93         if (!obj->iopgd || !IS_ALIGNED((u32)obj->iopgd,  SZ_16K))
  94                 return -EINVAL;
  95
  96         pa = virt_to_phys(obj->iopgd);
  97         if (!IS_ALIGNED(pa, SZ_16K))
  98                 return -EINVAL;
  99
 100         iommu_write_reg(obj, MMU_SYS_SOFTRESET, MMU_SYSCONFIG);
 101
 102         timeout = jiffies + msecs_to_jiffies(20);
 103         do {
 104                 l = iommu_read_reg(obj, MMU_SYSSTATUS);
 105                 if (l & MMU_SYS_RESETDONE)
 106                         break;
 107         } while (!time_after(jiffies, timeout));
 108
 109         if (!(l & MMU_SYS_RESETDONE)) {
 110                 dev_err(obj->dev, "can't take mmu out of reset\n");
 111                 return -ENODEV;
 112         }
 113
 114         l = iommu_read_reg(obj, MMU_REVISION);
 115         dev_info(obj->dev, "%s: version %d.%d\n", obj->name,
 116                  (l >> 4) & 0xf, l & 0xf);
 117
 118         l = iommu_read_reg(obj, MMU_SYSCONFIG);
 119         l &= ~MMU_SYS_IDLE_MASK;
 120         l |= (MMU_SYS_IDLE_SMART | MMU_SYS_AUTOIDLE);
 121         iommu_write_reg(obj, l, MMU_SYSCONFIG);
 122
 123         iommu_write_reg(obj, pa, MMU_TTB);
 124
 125         __iommu_set_twl(obj, true);
 126
 127         return 0;
 128 }
 129
 130 static void omap2_iommu_disable(struct iommu *obj)
 131 {
 132         u32 l = iommu_read_reg(obj, MMU_CNTL);
 133
 134         l &= ~MMU_CNTL_MASK;
 135         iommu_write_reg(obj, l, MMU_CNTL);
 136         iommu_write_reg(obj, MMU_SYS_IDLE_FORCE, MMU_SYSCONFIG);
 137
 138         dev_dbg(obj->dev, "%s is shutting down\n", obj->name);
 139 }
 140
 141 static void omap2_iommu_set_twl(struct iommu *obj, bool on)
 142 {
 143         __iommu_set_twl(obj, false);
 144 }
 145
 146 static u32 omap2_iommu_fault_isr(struct iommu *obj, u32 *ra)
 147 {
 148         u32 stat, da;
 149         u32 errs = 0;
 150
 151         stat = iommu_read_reg(obj, MMU_IRQSTATUS);
 152         stat &= MMU_IRQ_MASK;
 153         if (!stat) {
 154                 *ra = 0;
 155                 return 0;
 156         }
 157
 158         da = iommu_read_reg(obj, MMU_FAULT_AD);
 159         *ra = da;
 160
 161         if (stat & MMU_IRQ_TLBMISS)
 162                 errs |= OMAP_IOMMU_ERR_TLB_MISS;
 163         if (stat & MMU_IRQ_TRANSLATIONFAULT)
 164                 errs |= OMAP_IOMMU_ERR_TRANS_FAULT;
 165         if (stat & MMU_IRQ_EMUMISS)
 166                 errs |= OMAP_IOMMU_ERR_EMU_MISS;
 167         if (stat & MMU_IRQ_TABLEWALKFAULT)
 168                 errs |= OMAP_IOMMU_ERR_TBLWALK_FAULT;
 169         if (stat & MMU_IRQ_MULTIHITFAULT)
 170                 errs |= OMAP_IOMMU_ERR_MULTIHIT_FAULT;
 171         iommu_write_reg(obj, stat, MMU_IRQSTATUS);
 172
 173         return errs;
 174 }
 175
 176 static void omap2_tlb_read_cr(struct iommu *obj, struct cr_regs *cr)
 177 {
 178         cr->cam = iommu_read_reg(obj, MMU_READ_CAM);
 179         cr->ram = iommu_read_reg(obj, MMU_READ_RAM);
 180 }
 181
 182 static void omap2_tlb_load_cr(struct iommu *obj, struct cr_regs *cr)
 183 {
 184         iommu_write_reg(obj, cr->cam | MMU_CAM_V, MMU_CAM);
 185         iommu_write_reg(obj, cr->ram, MMU_RAM);
 186 }
 187
 188 static u32 omap2_cr_to_virt(struct cr_regs *cr)
 189 {
 190         u32 page_size = cr->cam & MMU_CAM_PGSZ_MASK;
 191         u32 mask = get_cam_va_mask(cr->cam & page_size);
 192
 193         return cr->cam & mask;
 194 }
 195
 196 static struct cr_regs *omap2_alloc_cr(struct iommu *obj, struct iotlb_entry *e)
 197 {
 198         struct cr_regs *cr;
 199
 200         if (e->da & ~(get_cam_va_mask(e->pgsz))) {
 201                 dev_err(obj->dev, "%s:\twrong alignment: %08x\n", __func__,
 202                         e->da);
 203                 return ERR_PTR(-EINVAL);
 204         }
 205
 206         cr = kmalloc(sizeof(*cr), GFP_KERNEL);
 207         if (!cr)
 208                 return ERR_PTR(-ENOMEM);
 209
 210         cr->cam = (e->da & MMU_CAM_VATAG_MASK) | e->prsvd | e->pgsz | e->valid;
 211         cr->ram = e->pa | e->endian | e->elsz | e->mixed;
 212
 213         return cr;
 214 }
 215
 216 static inline int omap2_cr_valid(struct cr_regs *cr)
 217 {
 218         return cr->cam & MMU_CAM_V;
 219 }
 220
 221 static u32 omap2_get_pte_attr(struct iotlb_entry *e)
 222 {
 223         u32 attr;
 224
 225         attr = e->mixed << 5;
 226         attr |= e->endian;
 227         attr |= e->elsz >> 3;
 228         attr <<= (((e->pgsz == MMU_CAM_PGSZ_4K) ||
 229                         (e->pgsz == MMU_CAM_PGSZ_64K)) ? 0 : 6);
 230         return attr;
 231 }
 232
 233 static ssize_t omap2_dump_cr(struct iommu *obj, struct cr_regs *cr, char *buf)
 234 {
 235         char *p = buf;
 236
 237         /* FIXME: Need more detail analysis of cam/ram */
 238         p += sprintf(p, "%08x %08x %01x\n", cr->cam, cr->ram,
 239                                         (cr->cam & MMU_CAM_P) ? 1 : 0);
 240
 241         return p - buf;
 242 }
 243
 244 #define pr_reg(name)                                                    \
 245         do {                                                            \
 246                 ssize_t bytes;                                          \
 247                 const char *str = "%20s: %08x\n";                       \
 248                 const int maxcol = 32;                                  \
 249                 bytes = snprintf(p, maxcol, str, __stringify(name),     \
 250                                  iommu_read_reg(obj, MMU_##name));      \
 251                 p += bytes;                                             \
 252                 len -= bytes;                                           \
 253                 if (len < maxcol)                                       \
 254                         goto out;                                       \
 255         } while (0)
 256
 257 static ssize_t omap2_iommu_dump_ctx(struct iommu *obj, char *buf, ssize_t len)
 258 {
 259         char *p = buf;
 260
 261         pr_reg(REVISION);
 262         pr_reg(SYSCONFIG);
 263         pr_reg(SYSSTATUS);
 264         pr_reg(IRQSTATUS);
 265         pr_reg(IRQENABLE);
 266         pr_reg(WALKING_ST);
 267         pr_reg(CNTL);
 268         pr_reg(FAULT_AD);
 269         pr_reg(TTB);
 270         pr_reg(LOCK);
 271         pr_reg(LD_TLB);
 272         pr_reg(CAM);
 273         pr_reg(RAM);
 274         pr_reg(GFLUSH);
 275         pr_reg(FLUSH_ENTRY);
 276         pr_reg(READ_CAM);
 277         pr_reg(READ_RAM);
 278         pr_reg(EMU_FAULT_AD);
 279 out:
 280         return p - buf;
 281 }
 282
 283 static void omap2_iommu_save_ctx(struct iommu *obj)
 284 {
 285         int i;
 286         u32 *p = obj->ctx;
 287
 288         for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
 289                 p[i] = iommu_read_reg(obj, i * sizeof(u32));
 290                 dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
 291         }
 292
 293         BUG_ON(p[0] != IOMMU_ARCH_VERSION);
 294 }
 295
 296 static void omap2_iommu_restore_ctx(struct iommu *obj)
 297 {
 298         int i;
 299         u32 *p = obj->ctx;
 300
 301         for (i = 0; i < (MMU_REG_SIZE / sizeof(u32)); i++) {
 302                 iommu_write_reg(obj, p[i], i * sizeof(u32));
 303                 dev_dbg(obj->dev, "%s\t[%02d] %08x\n", __func__, i, p[i]);
 304         }
 305
 306         BUG_ON(p[0] != IOMMU_ARCH_VERSION);
 307 }
 308
 309 static void omap2_cr_to_e(struct cr_regs *cr, struct iotlb_entry *e)
 310 {
 311         e->da           = cr->cam & MMU_CAM_VATAG_MASK;
 312         e->pa           = cr->ram & MMU_RAM_PADDR_MASK;
 313         e->valid        = cr->cam & MMU_CAM_V;
 314         e->pgsz         = cr->cam & MMU_CAM_PGSZ_MASK;
 315         e->endian       = cr->ram & MMU_RAM_ENDIAN_MASK;
 316         e->elsz         = cr->ram & MMU_RAM_ELSZ_MASK;
 317         e->mixed        = cr->ram & MMU_RAM_MIXED;
 318 }
 319
 320 static const struct iommu_functions omap2_iommu_ops = {
 321         .version        = IOMMU_ARCH_VERSION,
 322
 323         .enable         = omap2_iommu_enable,
 324         .disable        = omap2_iommu_disable,
 325         .set_twl        = omap2_iommu_set_twl,
 326         .fault_isr      = omap2_iommu_fault_isr,
 327
 328         .tlb_read_cr    = omap2_tlb_read_cr,
 329         .tlb_load_cr    = omap2_tlb_load_cr,
 330
 331         .cr_to_e        = omap2_cr_to_e,
 332         .cr_to_virt     = omap2_cr_to_virt,
 333         .alloc_cr       = omap2_alloc_cr,
 334         .cr_valid       = omap2_cr_valid,
 335         .dump_cr        = omap2_dump_cr,
 336
 337         .get_pte_attr   = omap2_get_pte_attr,
 338
 339         .save_ctx       = omap2_iommu_save_ctx,
 340         .restore_ctx    = omap2_iommu_restore_ctx,
 341         .dump_ctx       = omap2_iommu_dump_ctx,
 342 };
 343
 344 static int __init omap2_iommu_init(void)
 345 {
 346         return install_iommu_arch(&omap2_iommu_ops);
 347 }
 348 module_init(omap2_iommu_init);
 349
 350 static void __exit omap2_iommu_exit(void)
 351 {
 352         uninstall_iommu_arch(&omap2_iommu_ops);
 353 }
 354 module_exit(omap2_iommu_exit);
 355
 356 MODULE_AUTHOR("Hiroshi DOYU, Paul Mundt and Toshihiro Kobayashi");
 357 MODULE_DESCRIPTION("omap iommu: omap2/3 architecture specific functions");
 358 MODULE_LICENSE("GPL v2");