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/of_platform.h>
  20 #include <sysdev/fsl_soc.h>
  21 #include <asm/prom.h>
  22 #include <asm/hw_irq.h>
  23 #include <asm/ppc-pci.h>
  24 #include "fsl_msi.h"
  25
  26 struct fsl_msi_feature {
  27         u32 fsl_pic_ip;
  28         u32 msiir_offset;
  29 };
  30
  31 static struct fsl_msi *fsl_msi;
  32
  33 static inline u32 fsl_msi_read(u32 __iomem *base, unsigned int reg)
  34 {
  35         return in_be32(base + (reg >> 2));
  36 }
  37
  38 /*
  39  * We do not need this actually. The MSIR register has been read once
  40  * in the cascade interrupt. So, this MSI interrupt has been acked
  41 */
  42 static void fsl_msi_end_irq(unsigned int virq)
  43 {
  44 }
  45
  46 static struct irq_chip fsl_msi_chip = {
  47         .mask           = mask_msi_irq,
  48         .unmask         = unmask_msi_irq,
  49         .ack            = fsl_msi_end_irq,
  50         .name           = "FSL-MSI",
  51 };
  52
  53 static int fsl_msi_host_map(struct irq_host *h, unsigned int virq,
  54                                 irq_hw_number_t hw)
  55 {
  56         struct irq_chip *chip = &fsl_msi_chip;
  57
  58         irq_to_desc(virq)->status |= IRQ_TYPE_EDGE_FALLING;
  59
  60         set_irq_chip_and_handler(virq, chip, handle_edge_irq);
  61
  62         return 0;
  63 }
  64
  65 static struct irq_host_ops fsl_msi_host_ops = {
  66         .map = fsl_msi_host_map,
  67 };
  68
  69 static int fsl_msi_init_allocator(struct fsl_msi *msi_data)
  70 {
  71         int rc;
  72
  73         rc = msi_bitmap_alloc(&msi_data->bitmap, NR_MSI_IRQS,
  74                               msi_data->irqhost->of_node);
  75         if (rc)
  76                 return rc;
  77
  78         rc = msi_bitmap_reserve_dt_hwirqs(&msi_data->bitmap);
  79         if (rc < 0) {
  80                 msi_bitmap_free(&msi_data->bitmap);
  81                 return rc;
  82         }
  83
  84         return 0;
  85 }
  86
  87 static int fsl_msi_check_device(struct pci_dev *pdev, int nvec, int type)
  88 {
  89         if (type == PCI_CAP_ID_MSIX)
  90                 pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
  91
  92         return 0;
  93 }
  94
  95 static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
  96 {
  97         struct msi_desc *entry;
  98         struct fsl_msi *msi_data = fsl_msi;
  99
 100         list_for_each_entry(entry, &pdev->msi_list, list) {
 101                 if (entry->irq == NO_IRQ)
 102                         continue;
 103                 set_irq_msi(entry->irq, NULL);
 104                 msi_bitmap_free_hwirqs(&msi_data->bitmap,
 105                                        virq_to_hw(entry->irq), 1);
 106                 irq_dispose_mapping(entry->irq);
 107         }
 108
 109         return;
 110 }
 111
 112 static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
 113                                   struct msi_msg *msg)
 114 {
 115         struct fsl_msi *msi_data = fsl_msi;
 116         struct pci_controller *hose = pci_bus_to_host(pdev->bus);
 117         u32 base = 0;
 118
 119         pci_bus_read_config_dword(hose->bus,
 120                 PCI_DEVFN(0, 0), PCI_BASE_ADDRESS_0, &base);
 121
 122         msg->address_lo = msi_data->msi_addr_lo + base;
 123         msg->address_hi = msi_data->msi_addr_hi;
 124         msg->data = hwirq;
 125
 126         pr_debug("%s: allocated srs: %d, ibs: %d\n",
 127                 __func__, hwirq / IRQS_PER_MSI_REG, hwirq % IRQS_PER_MSI_REG);
 128 }
 129
 130 static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
 131 {
 132         int rc, hwirq;
 133         unsigned int virq;
 134         struct msi_desc *entry;
 135         struct msi_msg msg;
 136         struct fsl_msi *msi_data = fsl_msi;
 137
 138         list_for_each_entry(entry, &pdev->msi_list, list) {
 139                 hwirq = msi_bitmap_alloc_hwirqs(&msi_data->bitmap, 1);
 140                 if (hwirq < 0) {
 141                         rc = hwirq;
 142                         pr_debug("%s: fail allocating msi interrupt\n",
 143                                         __func__);
 144                         goto out_free;
 145                 }
 146
 147                 virq = irq_create_mapping(msi_data->irqhost, hwirq);
 148
 149                 if (virq == NO_IRQ) {
 150                         pr_debug("%s: fail mapping hwirq 0x%x\n",
 151                                         __func__, hwirq);
 152                         msi_bitmap_free_hwirqs(&msi_data->bitmap, hwirq, 1);
 153                         rc = -ENOSPC;
 154                         goto out_free;
 155                 }
 156                 set_irq_msi(virq, entry);
 157
 158                 fsl_compose_msi_msg(pdev, hwirq, &msg);
 159                 write_msi_msg(virq, &msg);
 160         }
 161         return 0;
 162
 163 out_free:
 164         return rc;
 165 }
 166
 167 static void fsl_msi_cascade(unsigned int irq, struct irq_desc *desc)
 168 {
 169         unsigned int cascade_irq;
 170         struct fsl_msi *msi_data = fsl_msi;
 171         int msir_index = -1;
 172         u32 msir_value = 0;
 173         u32 intr_index;
 174         u32 have_shift = 0;
 175
 176         raw_spin_lock(&desc->lock);
 177         if ((msi_data->feature &  FSL_PIC_IP_MASK) == FSL_PIC_IP_IPIC) {
 178                 if (desc->chip->mask_ack)
 179                         desc->chip->mask_ack(irq);
 180                 else {
 181                         desc->chip->mask(irq);
 182                         desc->chip->ack(irq);
 183                 }
 184         }
 185
 186         if (unlikely(desc->status & IRQ_INPROGRESS))
 187                 goto unlock;
 188
 189         msir_index = (int)desc->handler_data;
 190
 191         if (msir_index >= NR_MSI_REG)
 192                 cascade_irq = NO_IRQ;
 193
 194         desc->status |= IRQ_INPROGRESS;
 195         switch (fsl_msi->feature & FSL_PIC_IP_MASK) {
 196         case FSL_PIC_IP_MPIC:
 197                 msir_value = fsl_msi_read(msi_data->msi_regs,
 198                         msir_index * 0x10);
 199                 break;
 200         case FSL_PIC_IP_IPIC:
 201                 msir_value = fsl_msi_read(msi_data->msi_regs, msir_index * 0x4);
 202                 break;
 203         }
 204
 205         while (msir_value) {
 206                 intr_index = ffs(msir_value) - 1;
 207
 208                 cascade_irq = irq_linear_revmap(msi_data->irqhost,
 209                                 msir_index * IRQS_PER_MSI_REG +
 210                                         intr_index + have_shift);
 211                 if (cascade_irq != NO_IRQ)
 212                         generic_handle_irq(cascade_irq);
 213                 have_shift += intr_index + 1;
 214                 msir_value = msir_value >> (intr_index + 1);
 215         }
 216         desc->status &= ~IRQ_INPROGRESS;
 217
 218         switch (msi_data->feature & FSL_PIC_IP_MASK) {
 219         case FSL_PIC_IP_MPIC:
 220                 desc->chip->eoi(irq);
 221                 break;
 222         case FSL_PIC_IP_IPIC:
 223                 if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
 224                         desc->chip->unmask(irq);
 225                 break;
 226         }
 227 unlock:
 228         raw_spin_unlock(&desc->lock);
 229 }
 230
 231 static int __devinit fsl_of_msi_probe(struct of_device *dev,
 232                                 const struct of_device_id *match)
 233 {
 234         struct fsl_msi *msi;
 235         struct resource res;
 236         int err, i, count;
 237         int rc;
 238         int virt_msir;
 239         const u32 *p;
 240         struct fsl_msi_feature *features = match->data;
 241
 242         printk(KERN_DEBUG "Setting up Freescale MSI support\n");
 243
 244         msi = kzalloc(sizeof(struct fsl_msi), GFP_KERNEL);
 245         if (!msi) {
 246                 dev_err(&dev->dev, "No memory for MSI structure\n");
 247                 err = -ENOMEM;
 248                 goto error_out;
 249         }
 250
 251         msi->irqhost = irq_alloc_host(dev->node, IRQ_HOST_MAP_LINEAR,
 252                                       NR_MSI_IRQS, &fsl_msi_host_ops, 0);
 253
 254         if (msi->irqhost == NULL) {
 255                 dev_err(&dev->dev, "No memory for MSI irqhost\n");
 256                 err = -ENOMEM;
 257                 goto error_out;
 258         }
 259
 260         /* Get the MSI reg base */
 261         err = of_address_to_resource(dev->node, 0, &res);
 262         if (err) {
 263                 dev_err(&dev->dev, "%s resource error!\n",
 264                                 dev->node->full_name);
 265                 goto error_out;
 266         }
 267
 268         msi->msi_regs = ioremap(res.start, res.end - res.start + 1);
 269         if (!msi->msi_regs) {
 270                 dev_err(&dev->dev, "ioremap problem failed\n");
 271                 goto error_out;
 272         }
 273
 274         msi->feature = features->fsl_pic_ip;
 275
 276         msi->irqhost->host_data = msi;
 277
 278         msi->msi_addr_hi = 0x0;
 279         msi->msi_addr_lo = features->msiir_offset + (res.start & 0xfffff);
 280
 281         rc = fsl_msi_init_allocator(msi);
 282         if (rc) {
 283                 dev_err(&dev->dev, "Error allocating MSI bitmap\n");
 284                 goto error_out;
 285         }
 286
 287         p = of_get_property(dev->node, "interrupts", &count);
 288         if (!p) {
 289                 dev_err(&dev->dev, "no interrupts property found on %s\n",
 290                                 dev->node->full_name);
 291                 err = -ENODEV;
 292                 goto error_out;
 293         }
 294         if (count % 8 != 0) {
 295                 dev_err(&dev->dev, "Malformed interrupts property on %s\n",
 296                                 dev->node->full_name);
 297                 err = -EINVAL;
 298                 goto error_out;
 299         }
 300
 301         count /= sizeof(u32);
 302         for (i = 0; i < count / 2; i++) {
 303                 if (i > NR_MSI_REG)
 304                         break;
 305                 virt_msir = irq_of_parse_and_map(dev->node, i);
 306                 if (virt_msir != NO_IRQ) {
 307                         set_irq_data(virt_msir, (void *)i);
 308                         set_irq_chained_handler(virt_msir, fsl_msi_cascade);
 309                 }
 310         }
 311
 312         fsl_msi = msi;
 313
 314         WARN_ON(ppc_md.setup_msi_irqs);
 315         ppc_md.setup_msi_irqs = fsl_setup_msi_irqs;
 316         ppc_md.teardown_msi_irqs = fsl_teardown_msi_irqs;
 317         ppc_md.msi_check_device = fsl_msi_check_device;
 318         return 0;
 319 error_out:
 320         kfree(msi);
 321         return err;
 322 }
 323
 324 static const struct fsl_msi_feature mpic_msi_feature = {
 325         .fsl_pic_ip = FSL_PIC_IP_MPIC,
 326         .msiir_offset = 0x140,
 327 };
 328
 329 static const struct fsl_msi_feature ipic_msi_feature = {
 330         .fsl_pic_ip = FSL_PIC_IP_IPIC,
 331         .msiir_offset = 0x38,
 332 };
 333
 334 static const struct of_device_id fsl_of_msi_ids[] = {
 335         {
 336                 .compatible = "fsl,mpic-msi",
 337                 .data = (void *)&mpic_msi_feature,
 338         },
 339         {
 340                 .compatible = "fsl,ipic-msi",
 341                 .data = (void *)&ipic_msi_feature,
 342         },
 343         {}
 344 };
 345
 346 static struct of_platform_driver fsl_of_msi_driver = {
 347         .name = "fsl-msi",
 348         .match_table = fsl_of_msi_ids,
 349         .probe = fsl_of_msi_probe,
 350 };
 351
 352 static __init int fsl_of_msi_init(void)
 353 {
 354         return of_register_platform_driver(&fsl_of_msi_driver);
 355 }
 356
 357 subsys_initcall(fsl_of_msi_init);