arch/powerpc/sysdev/fsl_msi.c

   1 /*
   2  * Copyright (C) 2007-2008 Freescale Semiconductor, Inc. All rights reserved.
   3  *
   4  * Author: Tony Li <tony.li@freescale.com>
   5  *         Jason Jin <Jason.jin@freescale.com>
   6  *
   7  * The hwirq alloc and free code reuse from sysdev/mpic_msi.c
   8  *
   9  * This program is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU General Public License
  11  * as published by the Free Software Foundation; version 2 of the
  12  * License.
  13  *
  14  */
  15 #include <linux/irq.h>
  16 #include <linux/bootmem.h>
  17 #include <linux/bitmap.h>
  18 #include <linux/msi.h>
  19 #include <linux/pci.h>
  20 #include <linux/of_platform.h>
  21 #include <sysdev/fsl_soc.h>
  22 #include <asm/prom.h>
  23 #include <asm/hw_irq.h>
  24 #include <asm/ppc-pci.h>
  25 #include "fsl_msi.h"
  26
  27 struct fsl_msi_feature {
  28         u32 fsl_pic_ip;
  29         u32 msiir_offset;
  30 };
  31
  32 static struct fsl_msi *fsl_msi;
  33
  34 static inline u32 fsl_msi_read(u32 __iomem *base, unsigned int reg)
  35 {
  36         return in_be32(base + (reg >> 2));
  37 }
  38
  39 /*
  40  * We do not need this actually. The MSIR register has been read once
  41  * in the cascade interrupt. So, this MSI interrupt has been acked
  42 */
  43 static void fsl_msi_end_irq(unsigned int virq)
  44 {
  45 }
  46
  47 static struct irq_chip fsl_msi_chip = {
  48         .mask           = mask_msi_irq,
  49         .unmask         = unmask_msi_irq,
  50         .ack            = fsl_msi_end_irq,
  51         .typename       = " FSL-MSI  ",
  52 };
  53
  54 static int fsl_msi_host_map(struct irq_host *h, unsigned int virq,
  55                                 irq_hw_number_t hw)
  56 {
  57         struct irq_chip *chip = &fsl_msi_chip;
  58
  59         get_irq_desc(virq)->status |= IRQ_TYPE_EDGE_FALLING;
  60
  61         set_irq_chip_and_handler(virq, chip, handle_edge_irq);
  62
  63         return 0;
  64 }
  65
  66 static struct irq_host_ops fsl_msi_host_ops = {
  67         .map = fsl_msi_host_map,
  68 };
  69
  70 static irq_hw_number_t fsl_msi_alloc_hwirqs(struct fsl_msi *msi, int num)
  71 {
  72         unsigned long flags;
  73         int order = get_count_order(num);
  74         int offset;
  75
  76         spin_lock_irqsave(&msi->bitmap_lock, flags);
  77
  78         offset = bitmap_find_free_region(msi->fsl_msi_bitmap,
  79                                         NR_MSI_IRQS, order);
  80
  81         spin_unlock_irqrestore(&msi->bitmap_lock, flags);
  82
  83         pr_debug("%s: allocated 0x%x (2^%d) at offset 0x%x\n",
  84                 __func__, num, order, offset);
  85
  86         return offset;
  87 }
  88
  89 static void fsl_msi_free_hwirqs(struct fsl_msi *msi, int offset, int num)
  90 {
  91         unsigned long flags;
  92         int order = get_count_order(num);
  93
  94         pr_debug("%s: freeing 0x%x (2^%d) at offset 0x%x\n",
  95                 __func__, num, order, offset);
  96
  97         spin_lock_irqsave(&msi->bitmap_lock, flags);
  98         bitmap_release_region(msi->fsl_msi_bitmap, offset, order);
  99         spin_unlock_irqrestore(&msi->bitmap_lock, flags);
 100 }
 101
 102 static int fsl_msi_free_dt_hwirqs(struct fsl_msi *msi)
 103 {
 104         int i;
 105         int len;
 106         const u32 *p;
 107
 108         bitmap_allocate_region(msi->fsl_msi_bitmap, 0,
 109                        get_count_order(NR_MSI_IRQS));
 110
 111         p = of_get_property(msi->of_node, "msi-available-ranges", &len);
 112
 113         if (!p) {
 114                 /* No msi-available-ranges property,
 115                  * All the 256 MSI interrupts can be used
 116                  */
 117                 fsl_msi_free_hwirqs(msi, 0, 0x100);
 118                 return 0;
 119         }
 120
 121         if ((len % (2 * sizeof(u32))) != 0) {
 122                 printk(KERN_WARNING "fsl_msi: Malformed msi-available-ranges "
 123                        "property on %s\n", msi->of_node->full_name);
 124                 return -EINVAL;
 125         }
 126
 127         /* Format is: (<u32 start> <u32 count>)+ */
 128         len /= 2 * sizeof(u32);
 129         for (i = 0; i < len; i++, p += 2)
 130                 fsl_msi_free_hwirqs(msi, *p, *(p + 1));
 131
 132         return 0;
 133 }
 134
 135 static int fsl_msi_init_allocator(struct fsl_msi *msi_data)
 136 {
 137         int rc;
 138         int size = BITS_TO_LONGS(NR_MSI_IRQS) * sizeof(u32);
 139
 140         msi_data->fsl_msi_bitmap = kzalloc(size, GFP_KERNEL);
 141
 142         if (msi_data->fsl_msi_bitmap == NULL) {
 143                 pr_debug("%s: ENOMEM allocating allocator bitmap!\n",
 144                                 __func__);
 145                 return -ENOMEM;
 146         }
 147
 148         rc = fsl_msi_free_dt_hwirqs(msi_data);
 149         if (rc)
 150                 goto out_free;
 151
 152         return 0;
 153 out_free:
 154         kfree(msi_data->fsl_msi_bitmap);
 155
 156         msi_data->fsl_msi_bitmap = NULL;
 157         return rc;
 158
 159 }
 160
 161 static int fsl_msi_check_device(struct pci_dev *pdev, int nvec, int type)
 162 {
 163         if (type == PCI_CAP_ID_MSIX)
 164                 pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
 165
 166         return 0;
 167 }
 168
 169 static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
 170 {
 171         struct msi_desc *entry;
 172         struct fsl_msi *msi_data = fsl_msi;
 173
 174         list_for_each_entry(entry, &pdev->msi_list, list) {
 175                 if (entry->irq == NO_IRQ)
 176                         continue;
 177                 set_irq_msi(entry->irq, NULL);
 178                 fsl_msi_free_hwirqs(msi_data, virq_to_hw(entry->irq), 1);
 179                 irq_dispose_mapping(entry->irq);
 180         }
 181
 182         return;
 183 }
 184
 185 static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
 186                                   struct msi_msg *msg)
 187 {
 188         struct fsl_msi *msi_data = fsl_msi;
 189
 190         msg->address_lo = msi_data->msi_addr_lo;
 191         msg->address_hi = msi_data->msi_addr_hi;
 192         msg->data = hwirq;
 193
 194         pr_debug("%s: allocated srs: %d, ibs: %d\n",
 195                 __func__, hwirq / IRQS_PER_MSI_REG, hwirq % IRQS_PER_MSI_REG);
 196 }
 197
 198 static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 199 {
 200         irq_hw_number_t hwirq;
 201         int rc;
 202         unsigned int virq;
 203         struct msi_desc *entry;
 204         struct msi_msg msg;
 205         struct fsl_msi *msi_data = fsl_msi;
 206
 207         list_for_each_entry(entry, &pdev->msi_list, list) {
 208                 hwirq = fsl_msi_alloc_hwirqs(msi_data, 1);
 209                 if (hwirq < 0) {
 210                         rc = hwirq;
 211                         pr_debug("%s: fail allocating msi interrupt\n",
 212                                         __func__);
 213                         goto out_free;
 214                 }
 215
 216                 virq = irq_create_mapping(msi_data->irqhost, hwirq);
 217
 218                 if (virq == NO_IRQ) {
 219                         pr_debug("%s: fail mapping hwirq 0x%lx\n",
 220                                         __func__, hwirq);
 221                         fsl_msi_free_hwirqs(msi_data, hwirq, 1);
 222                         rc = -ENOSPC;
 223                         goto out_free;
 224                 }
 225                 set_irq_msi(virq, entry);
 226
 227                 fsl_compose_msi_msg(pdev, hwirq, &msg);
 228                 write_msi_msg(virq, &msg);
 229         }
 230         return 0;
 231
 232 out_free:
 233         return rc;
 234 }
 235
 236 static void fsl_msi_cascade(unsigned int irq, struct irq_desc *desc)
 237 {
 238         unsigned int cascade_irq;
 239         struct fsl_msi *msi_data = fsl_msi;
 240         int msir_index = -1;
 241         u32 msir_value = 0;
 242         u32 intr_index;
 243         u32 have_shift = 0;
 244
 245         spin_lock(&desc->lock);
 246         if ((msi_data->feature &  FSL_PIC_IP_MASK) == FSL_PIC_IP_IPIC) {
 247                 if (desc->chip->mask_ack)
 248                         desc->chip->mask_ack(irq);
 249                 else {
 250                         desc->chip->mask(irq);
 251                         desc->chip->ack(irq);
 252                 }
 253         }
 254
 255         if (unlikely(desc->status & IRQ_INPROGRESS))
 256                 goto unlock;
 257
 258         msir_index = (int)desc->handler_data;
 259
 260         if (msir_index >= NR_MSI_REG)
 261                 cascade_irq = NO_IRQ;
 262
 263         desc->status |= IRQ_INPROGRESS;
 264         switch (fsl_msi->feature & FSL_PIC_IP_MASK) {
 265         case FSL_PIC_IP_MPIC:
 266                 msir_value = fsl_msi_read(msi_data->msi_regs,
 267                         msir_index * 0x10);
 268                 break;
 269         case FSL_PIC_IP_IPIC:
 270                 msir_value = fsl_msi_read(msi_data->msi_regs, msir_index * 0x4);
 271                 break;
 272         }
 273
 274         while (msir_value) {
 275                 intr_index = ffs(msir_value) - 1;
 276
 277                 cascade_irq = irq_linear_revmap(msi_data->irqhost,
 278                                 msir_index * IRQS_PER_MSI_REG +
 279                                         intr_index + have_shift);
 280                 if (cascade_irq != NO_IRQ)
 281                         generic_handle_irq(cascade_irq);
 282                 have_shift += intr_index + 1;
 283                 msir_value = msir_value >> (intr_index + 1);
 284         }
 285         desc->status &= ~IRQ_INPROGRESS;
 286
 287         switch (msi_data->feature & FSL_PIC_IP_MASK) {
 288         case FSL_PIC_IP_MPIC:
 289                 desc->chip->eoi(irq);
 290                 break;
 291         case FSL_PIC_IP_IPIC:
 292                 if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
 293                         desc->chip->unmask(irq);
 294                 break;
 295         }
 296 unlock:
 297         spin_unlock(&desc->lock);
 298 }
 299
 300 static int __devinit fsl_of_msi_probe(struct of_device *dev,
 301                                 const struct of_device_id *match)
 302 {
 303         struct fsl_msi *msi;
 304         struct resource res;
 305         int err, i, count;
 306         int rc;
 307         int virt_msir;
 308         const u32 *p;
 309         struct fsl_msi_feature *features = match->data;
 310
 311         printk(KERN_DEBUG "Setting up Freescale MSI support\n");
 312
 313         msi = kzalloc(sizeof(struct fsl_msi), GFP_KERNEL);
 314         if (!msi) {
 315                 dev_err(&dev->dev, "No memory for MSI structure\n");
 316                 err = -ENOMEM;
 317                 goto error_out;
 318         }
 319
 320         msi->of_node = of_node_get(dev->node);
 321
 322         msi->irqhost = irq_alloc_host(of_node_get(dev->node),
 323                                 IRQ_HOST_MAP_LINEAR,
 324                                 NR_MSI_IRQS, &fsl_msi_host_ops, 0);
 325         if (msi->irqhost == NULL) {
 326                 dev_err(&dev->dev, "No memory for MSI irqhost\n");
 327                 of_node_put(dev->node);
 328                 err = -ENOMEM;
 329                 goto error_out;
 330         }
 331
 332         /* Get the MSI reg base */
 333         err = of_address_to_resource(dev->node, 0, &res);
 334         if (err) {
 335                 dev_err(&dev->dev, "%s resource error!\n",
 336                                 dev->node->full_name);
 337                 goto error_out;
 338         }
 339
 340         msi->msi_regs = ioremap(res.start, res.end - res.start + 1);
 341         if (!msi->msi_regs) {
 342                 dev_err(&dev->dev, "ioremap problem failed\n");
 343                 goto error_out;
 344         }
 345
 346         msi->feature = features->fsl_pic_ip;
 347
 348         msi->irqhost->host_data = msi;
 349
 350         msi->msi_addr_hi = 0x0;
 351         msi->msi_addr_lo = res.start + features->msiir_offset;
 352
 353         rc = fsl_msi_init_allocator(msi);
 354         if (rc) {
 355                 dev_err(&dev->dev, "Error allocating MSI bitmap\n");
 356                 goto error_out;
 357         }
 358
 359         p = of_get_property(dev->node, "interrupts", &count);
 360         if (!p) {
 361                 dev_err(&dev->dev, "no interrupts property found on %s\n",
 362                                 dev->node->full_name);
 363                 err = -ENODEV;
 364                 goto error_out;
 365         }
 366         if (count % 8 != 0) {
 367                 dev_err(&dev->dev, "Malformed interrupts property on %s\n",
 368                                 dev->node->full_name);
 369                 err = -EINVAL;
 370                 goto error_out;
 371         }
 372
 373         count /= sizeof(u32);
 374         for (i = 0; i < count / 2; i++) {
 375                 if (i > NR_MSI_REG)
 376                         break;
 377                 virt_msir = irq_of_parse_and_map(dev->node, i);
 378                 if (virt_msir != NO_IRQ) {
 379                         set_irq_data(virt_msir, (void *)i);
 380                         set_irq_chained_handler(virt_msir, fsl_msi_cascade);
 381                 }
 382         }
 383
 384         fsl_msi = msi;
 385
 386         WARN_ON(ppc_md.setup_msi_irqs);
 387         ppc_md.setup_msi_irqs = fsl_setup_msi_irqs;
 388         ppc_md.teardown_msi_irqs = fsl_teardown_msi_irqs;
 389         ppc_md.msi_check_device = fsl_msi_check_device;
 390         return 0;
 391 error_out:
 392         kfree(msi);
 393         return err;
 394 }
 395
 396 static const struct fsl_msi_feature mpic_msi_feature = {
 397         .fsl_pic_ip = FSL_PIC_IP_MPIC,
 398         .msiir_offset = 0x140,
 399 };
 400
 401 static const struct fsl_msi_feature ipic_msi_feature = {
 402         .fsl_pic_ip = FSL_PIC_IP_IPIC,
 403         .msiir_offset = 0x38,
 404 };
 405
 406 static const struct of_device_id fsl_of_msi_ids[] = {
 407         {
 408                 .compatible = "fsl,mpic-msi",
 409                 .data = (void *)&mpic_msi_feature,
 410         },
 411         {
 412                 .compatible = "fsl,ipic-msi",
 413                 .data = (void *)&ipic_msi_feature,
 414         },
 415         {}
 416 };
 417
 418 static struct of_platform_driver fsl_of_msi_driver = {
 419         .name = "fsl-msi",
 420         .match_table = fsl_of_msi_ids,
 421         .probe = fsl_of_msi_probe,
 422 };
 423
 424 static __init int fsl_of_msi_init(void)
 425 {
 426         return of_register_platform_driver(&fsl_of_msi_driver);
 427 }
 428
 429 subsys_initcall(fsl_of_msi_init);