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/msi.h>
  18 #include <linux/pci.h>
  19 #include <linux/slab.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         .name           = "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         irq_to_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 int fsl_msi_init_allocator(struct fsl_msi *msi_data)
  71 {
  72         int rc;
  73
  74         rc = msi_bitmap_alloc(&msi_data->bitmap, NR_MSI_IRQS,
  75                               msi_data->irqhost->of_node);
  76         if (rc)
  77                 return rc;
  78
  79         rc = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
  80         if (rc < 0) {
  81                 msi_bitmap_free(&msi_data->bitmap);
  82                 return rc;
  83         }
  84
  85         return 0;
  86 }
  87
  88 static int fsl_msi_check_device(struct pci_dev *pdev, int nvec, int type)
  89 {
  90         if (type == PCI_CAP_ID_MSIX)
  91                 pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
  92
  93         return 0;
  94 }
  95
  96 static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
  97 {
  98         struct msi_desc *entry;
  99         struct fsl_msi *msi_data = fsl_msi;
 100
 101         list_for_each_entry(entry, &pdev->msi_list, list) {
 102                 if (entry->irq == NO_IRQ)
 103                         continue;
 104                 set_irq_msi(entry->irq, NULL);
 105                 msi_bitmap_free_hwirqs(&msi_data->bitmap,
 106                                        virq_to_hw(entry->irq), 1);
 107                 irq_dispose_mapping(entry->irq);
 108         }
 109
 110         return;
 111 }
 112
 113 static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
 114                                   struct msi_msg *msg)
 115 {
 116         struct fsl_msi *msi_data = fsl_msi;
 117         struct pci_controller *hose = pci_bus_to_host(pdev->bus);
 118         u32 base = 0;
 119
 120         pci_bus_read_config_dword(hose->bus,
 121                 PCI_DEVFN(0, 0), PCI_BASE_ADDRESS_0, &base);
 122
 123         msg->address_lo = msi_data->msi_addr_lo + base;
 124         msg->address_hi = msi_data->msi_addr_hi;
 125         msg->data = hwirq;
 126
 127         pr_debug("%s: allocated srs: %d, ibs: %d\n",
 128                 __func__, hwirq / IRQS_PER_MSI_REG, hwirq % IRQS_PER_MSI_REG);
 129 }
 130
 131 static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 132 {
 133         int rc, hwirq;
 134         unsigned int virq;
 135         struct msi_desc *entry;
 136         struct msi_msg msg;
 137         struct fsl_msi *msi_data = fsl_msi;
 138
 139         list_for_each_entry(entry, &pdev->msi_list, list) {
 140                 hwirq = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
 141                 if (hwirq < 0) {
 142                         rc = hwirq;
 143                         pr_debug("%s: fail allocating msi interrupt\n",
 144                                         __func__);
 145                         goto out_free;
 146                 }
 147
 148                 virq = irq_create_mapping(msi_data->irqhost, hwirq);
 149
 150                 if (virq == NO_IRQ) {
 151                         pr_debug("%s: fail mapping hwirq 0x%x\n",
 152                                         __func__, hwirq);
 153                         msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
 154                         rc = -ENOSPC;
 155                         goto out_free;
 156                 }
 157                 set_irq_msi(virq, entry);
 158
 159                 fsl_compose_msi_msg(pdev, hwirq, &msg);
 160                 write_msi_msg(virq, &msg);
 161         }
 162         return 0;
 163
 164 out_free:
 165         return rc;
 166 }
 167
 168 static void fsl_msi_cascade(unsigned int irq, struct irq_desc *desc)
 169 {
 170         unsigned int cascade_irq;
 171         struct fsl_msi *msi_data = fsl_msi;
 172         int msir_index = -1;
 173         u32 msir_value = 0;
 174         u32 intr_index;
 175         u32 have_shift = 0;
 176
 177         raw_spin_lock(&desc->lock);
 178         if ((msi_data->feature &  FSL_PIC_IP_MASK) == FSL_PIC_IP_IPIC) {
 179                 if (desc->chip->mask_ack)
 180                         desc->chip->mask_ack(irq);
 181                 else {
 182                         desc->chip->mask(irq);
 183                         desc->chip->ack(irq);
 184                 }
 185         }
 186
 187         if (unlikely(desc->status & IRQ_INPROGRESS))
 188                 goto unlock;
 189
 190         msir_index = (int)desc->handler_data;
 191
 192         if (msir_index >= NR_MSI_REG)
 193                 cascade_irq = NO_IRQ;
 194
 195         desc->status |= IRQ_INPROGRESS;
 196         switch (fsl_msi->feature & FSL_PIC_IP_MASK) {
 197         case FSL_PIC_IP_MPIC:
 198                 msir_value = fsl_msi_read(msi_data->msi_regs,
 199                         msir_index * 0x10);
 200                 break;
 201         case FSL_PIC_IP_IPIC:
 202                 msir_value = fsl_msi_read(msi_data->msi_regs, msir_index * 0x4);
 203                 break;
 204         }
 205
 206         while (msir_value) {
 207                 intr_index = ffs(msir_value) - 1;
 208
 209                 cascade_irq = irq_linear_revmap(msi_data->irqhost,
 210                                 msir_index * IRQS_PER_MSI_REG +
 211                                         intr_index + have_shift);
 212                 if (cascade_irq != NO_IRQ)
 213                         generic_handle_irq(cascade_irq);
 214                 have_shift += intr_index + 1;
 215                 msir_value = msir_value >> (intr_index + 1);
 216         }
 217         desc->status &= ~IRQ_INPROGRESS;
 218
 219         switch (msi_data->feature & FSL_PIC_IP_MASK) {
 220         case FSL_PIC_IP_MPIC:
 221                 desc->chip->eoi(irq);
 222                 break;
 223         case FSL_PIC_IP_IPIC:
 224                 if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
 225                         desc->chip->unmask(irq);
 226                 break;
 227         }
 228 unlock:
 229         raw_spin_unlock(&desc->lock);
 230 }
 231
 232 static int __devinit fsl_of_msi_probe(struct of_device *dev,
 233                                 const struct of_device_id *match)
 234 {
 235         struct fsl_msi *msi;
 236         struct resource res;
 237         int err, i, count;
 238         int rc;
 239         int virt_msir;
 240         const u32 *p;
 241         struct fsl_msi_feature *features = match->data;
 242
 243         printk(KERN_DEBUG "Setting up Freescale MSI support\n");
 244
 245         msi = kzalloc(sizeof(struct fsl_msi), GFP_KERNEL);
 246         if (!msi) {
 247                 dev_err(&dev->dev, "No memory for MSI structure\n");
 248                 err = -ENOMEM;
 249                 goto error_out;
 250         }
 251
 252         msi->irqhost = irq_alloc_host(dev->dev.of_node, IRQ_HOST_MAP_LINEAR,
 253                                       NR_MSI_IRQS, &fsl_msi_host_ops, 0);
 254
 255         if (msi->irqhost == NULL) {
 256                 dev_err(&dev->dev, "No memory for MSI irqhost\n");
 257                 err = -ENOMEM;
 258                 goto error_out;
 259         }
 260
 261         /* Get the MSI reg base */
 262         err = of_address_to_resource(dev->dev.of_node, 0, &res);
 263         if (err) {
 264                 dev_err(&dev->dev, "%s resource error!\n",
 265                                 dev->dev.of_node->full_name);
 266                 goto error_out;
 267         }
 268
 269         msi->msi_regs = ioremap(res.start, res.end - res.start + 1);
 270         if (!msi->msi_regs) {
 271                 dev_err(&dev->dev, "ioremap problem failed\n");
 272                 goto error_out;
 273         }
 274
 275         msi->feature = features->fsl_pic_ip;
 276
 277         msi->irqhost->host_data = msi;
 278
 279         msi->msi_addr_hi = 0x0;
 280         msi->msi_addr_lo = features->msiir_offset + (res.start & 0xfffff);
 281
 282         rc = fsl_msi_init_allocator(msi);
 283         if (rc) {
 284                 dev_err(&dev->dev, "Error allocating MSI bitmap\n");
 285                 goto error_out;
 286         }
 287
 288         p = of_get_property(dev->dev.of_node, "interrupts", &count);
 289         if (!p) {
 290                 dev_err(&dev->dev, "no interrupts property found on %s\n",
 291                                 dev->dev.of_node->full_name);
 292                 err = -ENODEV;
 293                 goto error_out;
 294         }
 295         if (count % 8 != 0) {
 296                 dev_err(&dev->dev, "Malformed interrupts property on %s\n",
 297                                 dev->dev.of_node->full_name);
 298                 err = -EINVAL;
 299                 goto error_out;
 300         }
 301
 302         count /= sizeof(u32);
 303         for (i = 0; i < count / 2; i++) {
 304                 if (i > NR_MSI_REG)
 305                         break;
 306                 virt_msir = irq_of_parse_and_map(dev->dev.of_node, i);
 307                 if (virt_msir != NO_IRQ) {
 308                         set_irq_data(virt_msir, (void *)i);
 309                         set_irq_chained_handler(virt_msir, fsl_msi_cascade);
 310                 }
 311         }
 312
 313         fsl_msi = msi;
 314
 315         WARN_ON(ppc_md.setup_msi_irqs);
 316         ppc_md.setup_msi_irqs = fsl_setup_msi_irqs;
 317         ppc_md.teardown_msi_irqs = fsl_teardown_msi_irqs;
 318         ppc_md.msi_check_device = fsl_msi_check_device;
 319         return 0;
 320 error_out:
 321         kfree(msi);
 322         return err;
 323 }
 324
 325 static const struct fsl_msi_feature mpic_msi_feature = {
 326         .fsl_pic_ip = FSL_PIC_IP_MPIC,
 327         .msiir_offset = 0x140,
 328 };
 329
 330 static const struct fsl_msi_feature ipic_msi_feature = {
 331         .fsl_pic_ip = FSL_PIC_IP_IPIC,
 332         .msiir_offset = 0x38,
 333 };
 334
 335 static const struct of_device_id fsl_of_msi_ids[] = {
 336         {
 337                 .compatible = "fsl,mpic-msi",
 338                 .data = (void *)&mpic_msi_feature,
 339         },
 340         {
 341                 .compatible = "fsl,ipic-msi",
 342                 .data = (void *)&ipic_msi_feature,
 343         },
 344         {}
 345 };
 346
 347 static struct of_platform_driver fsl_of_msi_driver = {
 348         .driver = {
 349                 .name = "fsl-msi",
 350                 .owner = THIS_MODULE,
 351                 .of_match_table = fsl_of_msi_ids,
 352         },
 353         .probe = fsl_of_msi_probe,
 354 };
 355
 356 static __init int fsl_of_msi_init(void)
 357 {
 358         return of_register_platform_driver(&fsl_of_msi_driver);
 359 }
 360
 361 subsys_initcall(fsl_of_msi_init);