--- /dev/null
+/*
+ * Copyright (C) 2007-2008 Freescale Semiconductor, Inc. All rights reserved.
+ *
+ * Author: Tony Li <tony.li@freescale.com>
+ *        Jason Jin <Jason.jin@freescale.com>
+ *
+ * The hwirq alloc and free code reuse from sysdev/mpic_msi.c
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2 of the
+ * License.
+ *
+ */
+#include <linux/irq.h>
+#include <linux/bootmem.h>
+#include <linux/bitmap.h>
+#include <linux/msi.h>
+#include <linux/pci.h>
+#include <linux/of_platform.h>
+#include <sysdev/fsl_soc.h>
+#include <asm/prom.h>
+#include <asm/hw_irq.h>
+#include <asm/ppc-pci.h>
+#include "fsl_msi.h"
+
+struct fsl_msi_feature {
+       u32 fsl_pic_ip;
+       u32 msiir_offset;
+};
+
+static struct fsl_msi *fsl_msi;
+
+static inline u32 fsl_msi_read(u32 __iomem *base, unsigned int reg)
+{
+       return in_be32(base + (reg >> 2));
+}
+
+static inline void fsl_msi_write(u32 __iomem *base,
+                               unsigned int reg, u32 value)
+{
+       out_be32(base + (reg >> 2), value);
+}
+
+/*
+ * We do not need this actually. The MSIR register has been read once
+ * in the cascade interrupt. So, this MSI interrupt has been acked
+*/
+static void fsl_msi_end_irq(unsigned int virq)
+{
+}
+
+static struct irq_chip fsl_msi_chip = {
+       .mask           = mask_msi_irq,
+       .unmask         = unmask_msi_irq,
+       .ack            = fsl_msi_end_irq,
+       .typename       = " FSL-MSI  ",
+};
+
+static int fsl_msi_host_map(struct irq_host *h, unsigned int virq,
+                               irq_hw_number_t hw)
+{
+       struct irq_chip *chip = &fsl_msi_chip;
+
+       get_irq_desc(virq)->status |= IRQ_TYPE_EDGE_FALLING;
+
+       set_irq_chip_and_handler(virq, chip,  handle_edge_irq);
+
+       return 0;
+}
+
+static struct irq_host_ops fsl_msi_host_ops = {
+       .map = fsl_msi_host_map,
+};
+
+irq_hw_number_t fsl_msi_alloc_hwirqs(struct fsl_msi *msi, int num)
+{
+       unsigned long flags;
+       int offset, order = get_count_order(num);
+
+       spin_lock_irqsave(&msi->bitmap_lock, flags);
+
+       offset = bitmap_find_free_region(msi->fsl_msi_bitmap,
+                                       NR_MSI_IRQS, order);
+
+       spin_unlock_irqrestore(&msi->bitmap_lock, flags);
+
+       pr_debug("%s: allocated 0x%x (2^%d) at offset 0x%x\n",
+               __func__, num, order, offset);
+
+       return offset;
+}
+
+void fsl_msi_free_hwirqs(struct fsl_msi *msi, int offset, int num)
+{
+       unsigned long flags;
+       int order = get_count_order(num);
+
+       pr_debug("%s: freeing 0x%x (2^%d) at offset 0x%x\n",
+               __func__, num, order, offset);
+
+       spin_lock_irqsave(&msi->bitmap_lock, flags);
+       bitmap_release_region(msi->fsl_msi_bitmap, offset, order);
+       spin_unlock_irqrestore(&msi->bitmap_lock, flags);
+}
+
+static int fsl_msi_free_dt_hwirqs(struct fsl_msi *msi)
+{
+       int i, len;
+       const u32 *p;
+
+       bitmap_allocate_region(msi->fsl_msi_bitmap, 0,
+                      get_count_order(NR_MSI_IRQS));
+
+       p = of_get_property(msi->of_node, "msi-available-ranges", &len);
+
+       if (!p) {
+               /* No msi-available-ranges property,
+                * All the 256 MSI interrupts can be used
+                */
+               fsl_msi_free_hwirqs(msi, 0, 0x100);
+               return 0;
+       }
+
+       if ((len % (2 * sizeof(u32))) != 0) {
+               printk(KERN_WARNING "fsl_msi: Malformed msi-available-ranges "
+                      "property on %s\n", msi->of_node->full_name);
+               return -EINVAL;
+       }
+
+       /* Format is: (<u32 start> <u32 count>)+ */
+       len /= 2 * sizeof(u32);
+       for (i = 0; i < len; i++, p += 2)
+               fsl_msi_free_hwirqs(msi, *p, *(p + 1));
+
+       return 0;
+}
+
+static int fsl_msi_init_allocator(struct fsl_msi *msi_data)
+{
+       int rc, size;
+
+       size = BITS_TO_LONGS(NR_MSI_IRQS) * sizeof(u32);
+
+       msi_data->fsl_msi_bitmap = kzalloc(size, GFP_KERNEL);
+
+       if (msi_data->fsl_msi_bitmap == NULL) {
+               pr_debug("%s: ENOMEM allocating allocator bitmap!\n",
+                               __func__);
+               return -ENOMEM;
+       }
+
+       rc = fsl_msi_free_dt_hwirqs(msi_data);
+       if (rc)
+               goto out_free;
+
+       return 0;
+out_free:
+       kfree(msi_data->fsl_msi_bitmap);
+
+       msi_data->fsl_msi_bitmap = NULL;
+       return rc;
+
+}
+
+static int fsl_msi_check_device(struct pci_dev *pdev, int nvec, int type)
+{
+       if (type == PCI_CAP_ID_MSIX)
+               pr_debug("fslmsi: MSI-X untested, trying anyway.\n");
+
+       return 0;
+}
+
+static void fsl_teardown_msi_irqs(struct pci_dev *pdev)
+{
+       struct msi_desc *entry;
+       struct fsl_msi *msi_data = fsl_msi;
+
+       list_for_each_entry(entry, &pdev->msi_list, list) {
+               if (entry->irq == NO_IRQ)
+                       continue;
+               set_irq_msi(entry->irq, NULL);
+               fsl_msi_free_hwirqs(msi_data, virq_to_hw(entry->irq), 1);
+               irq_dispose_mapping(entry->irq);
+       }
+
+       return;
+}
+
+static void fsl_compose_msi_msg(struct pci_dev *pdev, int hwirq,
+                                 struct msi_msg *msg)
+{
+       struct fsl_msi *msi_data = fsl_msi;
+
+       msg->address_lo = msi_data->msi_addr_lo;
+       msg->address_hi = msi_data->msi_addr_hi;
+       msg->data = hwirq;
+
+       pr_debug("%s: allocated srs: %d, ibs: %d\n",
+               __func__, hwirq / IRQS_PER_MSI_REG, hwirq % IRQS_PER_MSI_REG);
+}
+
+static int fsl_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
+{
+       irq_hw_number_t hwirq;
+       int rc;
+       unsigned int virq;
+       struct msi_desc *entry;
+       struct msi_msg msg;
+       struct fsl_msi *msi_data = fsl_msi;
+
+       list_for_each_entry(entry, &pdev->msi_list, list) {
+               hwirq = fsl_msi_alloc_hwirqs(msi_data, 1);
+               if (hwirq < 0) {
+                       rc = hwirq;
+                       pr_debug("%s: fail allocating msi interrupt\n",
+                                       __func__);
+                       goto out_free;
+               }
+
+               virq = irq_create_mapping(msi_data->irqhost, hwirq);
+
+               if (virq == NO_IRQ) {
+                       pr_debug("%s: fail mapping hwirq 0x%lx\n",
+                                       __func__, hwirq);
+                       fsl_msi_free_hwirqs(msi_data, hwirq, 1);
+                       rc = -ENOSPC;
+                       goto out_free;
+               }
+               set_irq_msi(virq, entry);
+
+               fsl_compose_msi_msg(pdev, hwirq, &msg);
+               write_msi_msg(virq, &msg);
+       }
+       return 0;
+
+out_free:
+       return rc;
+}
+
+void fsl_msi_cascade(unsigned int irq, struct irq_desc *desc)
+{
+       unsigned int cascade_irq;
+       struct fsl_msi *msi_data = fsl_msi;
+       int msir_index = -1;
+       u32 msir_value = 0;
+       u32 intr_index;
+       u32 have_shift = 0;
+
+       spin_lock(&desc->lock);
+       if ((msi_data->feature &  FSL_PIC_IP_MASK) == FSL_PIC_IP_IPIC) {
+               if (desc->chip->mask_ack)
+                       desc->chip->mask_ack(irq);
+               else {
+                       desc->chip->mask(irq);
+                       desc->chip->ack(irq);
+               }
+       }
+
+       if (unlikely(desc->status & IRQ_INPROGRESS))
+               goto unlock;
+
+       msir_index = (int)(desc->handler_data);
+
+       if (msir_index >= NR_MSI_REG)
+               cascade_irq = NO_IRQ;
+
+       desc->status |= IRQ_INPROGRESS;
+       switch (fsl_msi->feature & FSL_PIC_IP_MASK) {
+       case FSL_PIC_IP_MPIC:
+               msir_value = fsl_msi_read(msi_data->msi_regs,
+                       msir_index * 0x10);
+               break;
+       case FSL_PIC_IP_IPIC:
+               msir_value = fsl_msi_read(msi_data->msi_regs, msir_index * 0x4);
+               break;
+       }
+
+       while (msir_value) {
+               intr_index = ffs(msir_value) - 1;
+
+               cascade_irq = irq_linear_revmap(msi_data->irqhost,
+                               (msir_index * IRQS_PER_MSI_REG +
+                                       intr_index + have_shift));
+               if (cascade_irq != NO_IRQ)
+                       generic_handle_irq(cascade_irq);
+               have_shift += (intr_index + 1);
+               msir_value = (msir_value >> (intr_index + 1));
+       }
+       desc->status &= ~IRQ_INPROGRESS;
+
+       switch (msi_data->feature & FSL_PIC_IP_MASK) {
+       case FSL_PIC_IP_MPIC:
+               desc->chip->eoi(irq);
+               break;
+       case FSL_PIC_IP_IPIC:
+               if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask)
+                       desc->chip->unmask(irq);
+               break;
+       }
+unlock:
+       spin_unlock(&desc->lock);
+}
+
+static int __devinit fsl_of_msi_probe(struct of_device *dev,
+                               const struct of_device_id *match)
+{
+       struct fsl_msi *msi;
+       struct resource res;
+       int err, i, count;
+       int rc;
+       int virt_msir;
+       const u32 *p;
+       struct fsl_msi_feature *tmp_data;
+
+       printk(KERN_DEBUG "Setting up Freescale MSI support\n");
+
+       msi = kzalloc(sizeof(struct fsl_msi), GFP_KERNEL);
+       if (!msi) {
+               dev_err(&dev->dev, "No memory for MSI structure\n");
+               err = -ENOMEM;
+               goto error_out;
+       }
+
+       msi->of_node = of_node_get(dev->node);
+
+       msi->irqhost = irq_alloc_host(of_node_get(dev->node),
+                               IRQ_HOST_MAP_LINEAR,
+                               NR_MSI_IRQS, &fsl_msi_host_ops, 0);
+       if (msi->irqhost == NULL) {
+               dev_err(&dev->dev, "No memory for MSI irqhost\n");
+               of_node_put(dev->node);
+               err = -ENOMEM;
+               goto error_out;
+       }
+
+       /* Get the MSI reg base */
+       err = of_address_to_resource(dev->node, 0, &res);
+       if (err) {
+               dev_err(&dev->dev, "%s resource error!\n",
+                               dev->node->full_name);
+               goto error_out;
+       }
+
+       msi->msi_regs = ioremap(res.start, res.end - res.start + 1);
+       if (!msi->msi_regs) {
+               dev_err(&dev->dev, "ioremap problem failed\n");
+               goto error_out;
+       }
+
+       tmp_data = (struct fsl_msi_feature *)match->data;
+
+       msi->feature = tmp_data->fsl_pic_ip;
+
+       msi->irqhost->host_data = msi;
+
+       msi->msi_addr_hi = 0x0;
+       msi->msi_addr_lo = res.start + tmp_data->msiir_offset;
+
+       rc = fsl_msi_init_allocator(msi);
+       if (rc) {
+               dev_err(&dev->dev, "Error allocating MSI bitmap\n");
+               goto error_out;
+       }
+
+       p = of_get_property(dev->node, "interrupts", &count);
+       if (!p) {
+               dev_err(&dev->dev, "no interrupts property found on %s\n",
+                               dev->node->full_name);
+               err = -ENODEV;
+               goto error_out;
+       }
+       if (count % 8 != 0) {
+               dev_err(&dev->dev, "Malformed interrupts property on %s\n",
+                               dev->node->full_name);
+               err = -EINVAL;
+               goto error_out;
+       }
+
+       count /= sizeof(u32);
+       for (i = 0; i < count / 2; i++) {
+               if (i > NR_MSI_REG)
+                       break;
+               virt_msir = irq_of_parse_and_map(dev->node, i);
+               if (virt_msir != NO_IRQ) {
+                       set_irq_data(virt_msir, (void *)i);
+                       set_irq_chained_handler(virt_msir, fsl_msi_cascade);
+               }
+       }
+
+       fsl_msi = msi;
+
+       WARN_ON(ppc_md.setup_msi_irqs);
+       ppc_md.setup_msi_irqs = fsl_setup_msi_irqs;
+       ppc_md.teardown_msi_irqs = fsl_teardown_msi_irqs;
+       ppc_md.msi_check_device = fsl_msi_check_device;
+       return 0;
+error_out:
+       kfree(msi);
+       return err;
+}
+
+static const struct fsl_msi_feature mpic_msi_feature = {
+       .fsl_pic_ip = FSL_PIC_IP_MPIC,
+       .msiir_offset = 0x140,
+};
+
+static const struct fsl_msi_feature ipic_msi_feature = {
+       .fsl_pic_ip = FSL_PIC_IP_IPIC,
+       .msiir_offset = 0x38,
+};
+
+static const struct of_device_id fsl_of_msi_ids[] = {
+       {
+               .compatible = "fsl,mpic-msi",
+               .data = (void *)&mpic_msi_feature,
+       },
+       {
+               .compatible = "fsl,ipic-msi",
+               .data = (void *)&ipic_msi_feature,
+       },
+       {}
+};
+
+static struct of_platform_driver fsl_of_msi_driver = {
+       .name = "fsl-msi",
+       .match_table = fsl_of_msi_ids,
+       .probe = fsl_of_msi_probe,
+};
+
+static __init int fsl_of_msi_init(void)
+{
+       return of_register_platform_driver(&fsl_of_msi_driver);
+}
+
+subsys_initcall(fsl_of_msi_init);