--- /dev/null
+/*
+ * Copyright 2007, Michael Ellerman, IBM Corporation.
+ *
+ * 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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/pci.h>
+#include <linux/msi.h>
+#include <linux/reboot.h>
+
+#include <asm/dcr.h>
+#include <asm/machdep.h>
+#include <asm/prom.h>
+
+
+/*
+ * MSIC registers, specified as offsets from dcr_base
+ */
+#define MSIC_CTRL_REG 0x0
+
+/* Base Address registers specify FIFO location in BE memory */
+#define MSIC_BASE_ADDR_HI_REG 0x3
+#define MSIC_BASE_ADDR_LO_REG 0x4
+
+/* Hold the read/write offsets into the FIFO */
+#define MSIC_READ_OFFSET_REG 0x5
+#define MSIC_WRITE_OFFSET_REG 0x6
+
+
+/* MSIC control register flags */
+#define MSIC_CTRL_ENABLE 0x0001
+#define MSIC_CTRL_FIFO_FULL_ENABLE 0x0002
+#define MSIC_CTRL_IRQ_ENABLE 0x0008
+#define MSIC_CTRL_FULL_STOP_ENABLE 0x0010
+
+/*
+ * The MSIC can be configured to use a FIFO of 32KB, 64KB, 128KB or 256KB.
+ * Currently we're using a 64KB FIFO size.
+ */
+#define MSIC_FIFO_SIZE_SHIFT 16
+#define MSIC_FIFO_SIZE_BYTES (1 << MSIC_FIFO_SIZE_SHIFT)
+
+/*
+ * To configure the FIFO size as (1 << n) bytes, we write (n - 15) into bits
+ * 8-9 of the MSIC control reg.
+ */
+#define MSIC_CTRL_FIFO_SIZE (((MSIC_FIFO_SIZE_SHIFT - 15) << 8) & 0x300)
+
+/*
+ * We need to mask the read/write offsets to make sure they stay within
+ * the bounds of the FIFO. Also they should always be 16-byte aligned.
+ */
+#define MSIC_FIFO_SIZE_MASK ((MSIC_FIFO_SIZE_BYTES - 1) & ~0xFu)
+
+/* Each entry in the FIFO is 16 bytes, the first 4 bytes hold the irq # */
+#define MSIC_FIFO_ENTRY_SIZE 0x10
+
+
+struct axon_msic {
+ struct device_node *dn;
+ struct irq_host *irq_host;
+ __le32 *fifo;
+ dcr_host_t dcr_host;
+ struct list_head list;
+ u32 read_offset;
+ u32 dcr_base;
+};
+
+static LIST_HEAD(axon_msic_list);
+
+static void msic_dcr_write(struct axon_msic *msic, unsigned int dcr_n, u32 val)
+{
+ pr_debug("axon_msi: dcr_write(0x%x, 0x%x)\n", val, dcr_n);
+
+ dcr_write(msic->dcr_host, msic->dcr_base + dcr_n, val);
+}
+
+static u32 msic_dcr_read(struct axon_msic *msic, unsigned int dcr_n)
+{
+ return dcr_read(msic->dcr_host, msic->dcr_base + dcr_n);
+}
+
+static void axon_msi_cascade(unsigned int irq, struct irq_desc *desc)
+{
+ struct axon_msic *msic = get_irq_data(irq);
+ u32 write_offset, msi;
+ int idx;
+
+ write_offset = msic_dcr_read(msic, MSIC_WRITE_OFFSET_REG);
+ pr_debug("axon_msi: original write_offset 0x%x\n", write_offset);
+
+ /* write_offset doesn't wrap properly, so we have to mask it */
+ write_offset &= MSIC_FIFO_SIZE_MASK;
+
+ while (msic->read_offset != write_offset) {
+ idx = msic->read_offset / sizeof(__le32);
+ msi = le32_to_cpu(msic->fifo[idx]);
+ msi &= 0xFFFF;
+
+ pr_debug("axon_msi: woff %x roff %x msi %x\n",
+ write_offset, msic->read_offset, msi);
+
+ msic->read_offset += MSIC_FIFO_ENTRY_SIZE;
+ msic->read_offset &= MSIC_FIFO_SIZE_MASK;
+
+ if (msi < NR_IRQS && irq_map[msi].host == msic->irq_host)
+ generic_handle_irq(msi);
+ else
+ pr_debug("axon_msi: invalid irq 0x%x!\n", msi);
+ }
+
+ desc->chip->eoi(irq);
+}
+
+static struct axon_msic *find_msi_translator(struct pci_dev *dev)
+{
+ struct irq_host *irq_host;
+ struct device_node *dn, *tmp;
+ const phandle *ph;
+ struct axon_msic *msic = NULL;
+
+ dn = pci_device_to_OF_node(dev);
+ if (!dn) {
+ dev_dbg(&dev->dev, "axon_msi: no pci_dn found\n");
+ return NULL;
+ }
+
+ for (; dn; tmp = of_get_parent(dn), of_node_put(dn), dn = tmp) {
+ ph = of_get_property(dn, "msi-translator", NULL);
+ if (ph)
+ break;
+ }
+
+ if (!ph) {
+ dev_dbg(&dev->dev,
+ "axon_msi: no msi-translator property found\n");
+ goto out_error;
+ }
+
+ tmp = dn;
+ dn = of_find_node_by_phandle(*ph);
+ if (!dn) {
+ dev_dbg(&dev->dev,
+ "axon_msi: msi-translator doesn't point to a node\n");
+ goto out_error;
+ }
+
+ irq_host = irq_find_host(dn);
+ if (!irq_host) {
+ dev_dbg(&dev->dev, "axon_msi: no irq_host found for node %s\n",
+ dn->full_name);
+ goto out_error;
+ }
+
+ msic = irq_host->host_data;
+
+out_error:
+ of_node_put(dn);
+ of_node_put(tmp);
+
+ return msic;
+}
+
+static int axon_msi_check_device(struct pci_dev *dev, int nvec, int type)
+{
+ if (!find_msi_translator(dev))
+ return -ENODEV;
+
+ return 0;
+}
+
+static int setup_msi_msg_address(struct pci_dev *dev, struct msi_msg *msg)
+{
+ struct device_node *dn, *tmp;
+ struct msi_desc *entry;
+ int len;
+ const u32 *prop;
+
+ dn = pci_device_to_OF_node(dev);
+ if (!dn) {
+ dev_dbg(&dev->dev, "axon_msi: no pci_dn found\n");
+ return -ENODEV;
+ }
+
+ entry = list_first_entry(&dev->msi_list, struct msi_desc, list);
+
+ for (; dn; tmp = of_get_parent(dn), of_node_put(dn), dn = tmp) {
+ if (entry->msi_attrib.is_64) {
+ prop = of_get_property(dn, "msi-address-64", &len);
+ if (prop)
+ break;
+ }
+
+ prop = of_get_property(dn, "msi-address-32", &len);
+ if (prop)
+ break;
+ }
+
+ if (!prop) {
+ dev_dbg(&dev->dev,
+ "axon_msi: no msi-address-(32|64) properties found\n");
+ return -ENOENT;
+ }
+
+ switch (len) {
+ case 8:
+ msg->address_hi = prop[0];
+ msg->address_lo = prop[1];
+ break;
+ case 4:
+ msg->address_hi = 0;
+ msg->address_lo = prop[0];
+ break;
+ default:
+ dev_dbg(&dev->dev,
+ "axon_msi: malformed msi-address-(32|64) property\n");
+ of_node_put(dn);
+ return -EINVAL;
+ }
+
+ of_node_put(dn);
+
+ return 0;
+}
+
+static int axon_msi_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
+{
+ unsigned int virq, rc;
+ struct msi_desc *entry;
+ struct msi_msg msg;
+ struct axon_msic *msic;
+
+ msic = find_msi_translator(dev);
+ if (!msic)
+ return -ENODEV;
+
+ rc = setup_msi_msg_address(dev, &msg);
+ if (rc)
+ return rc;
+
+ /* We rely on being able to stash a virq in a u16 */
+ BUILD_BUG_ON(NR_IRQS > 65536);
+
+ list_for_each_entry(entry, &dev->msi_list, list) {
+ virq = irq_create_direct_mapping(msic->irq_host);
+ if (virq == NO_IRQ) {
+ dev_warn(&dev->dev,
+ "axon_msi: virq allocation failed!\n");
+ return -1;
+ }
+ dev_dbg(&dev->dev, "axon_msi: allocated virq 0x%x\n", virq);
+
+ set_irq_msi(virq, entry);
+ msg.data = virq;
+ write_msi_msg(virq, &msg);
+ }
+
+ return 0;
+}
+
+static void axon_msi_teardown_msi_irqs(struct pci_dev *dev)
+{
+ struct msi_desc *entry;
+
+ dev_dbg(&dev->dev, "axon_msi: tearing down msi irqs\n");
+
+ list_for_each_entry(entry, &dev->msi_list, list) {
+ if (entry->irq == NO_IRQ)
+ continue;
+
+ set_irq_msi(entry->irq, NULL);
+ irq_dispose_mapping(entry->irq);
+ }
+}
+
+static struct irq_chip msic_irq_chip = {
+ .mask = mask_msi_irq,
+ .unmask = unmask_msi_irq,
+ .shutdown = unmask_msi_irq,
+ .typename = "AXON-MSI",
+};
+
+static int msic_host_map(struct irq_host *h, unsigned int virq,
+ irq_hw_number_t hw)
+{
+ set_irq_chip_and_handler(virq, &msic_irq_chip, handle_simple_irq);
+
+ return 0;
+}
+
+static int msic_host_match(struct irq_host *host, struct device_node *dn)
+{
+ struct axon_msic *msic = host->host_data;
+
+ return msic->dn == dn;
+}
+
+static struct irq_host_ops msic_host_ops = {
+ .match = msic_host_match,
+ .map = msic_host_map,
+};
+
+static int axon_msi_notify_reboot(struct notifier_block *nb,
+ unsigned long code, void *data)
+{
+ struct axon_msic *msic;
+ u32 tmp;
+
+ list_for_each_entry(msic, &axon_msic_list, list) {
+ pr_debug("axon_msi: disabling %s\n", msic->dn->full_name);
+ tmp = msic_dcr_read(msic, MSIC_CTRL_REG);
+ tmp &= ~MSIC_CTRL_ENABLE & ~MSIC_CTRL_IRQ_ENABLE;
+ msic_dcr_write(msic, MSIC_CTRL_REG, tmp);
+ }
+
+ return 0;
+}
+
+static struct notifier_block axon_msi_reboot_notifier = {
+ .notifier_call = axon_msi_notify_reboot
+};
+
+static int axon_msi_setup_one(struct device_node *dn)
+{
+ struct page *page;
+ struct axon_msic *msic;
+ unsigned int virq;
+ int dcr_len;
+
+ pr_debug("axon_msi: setting up dn %s\n", dn->full_name);
+
+ msic = kzalloc(sizeof(struct axon_msic), GFP_KERNEL);
+ if (!msic) {
+ printk(KERN_ERR "axon_msi: couldn't allocate msic for %s\n",
+ dn->full_name);
+ goto out;
+ }
+
+ msic->dcr_base = dcr_resource_start(dn, 0);
+ dcr_len = dcr_resource_len(dn, 0);
+
+ if (msic->dcr_base == 0 || dcr_len == 0) {
+ printk(KERN_ERR
+ "axon_msi: couldn't parse dcr properties on %s\n",
+ dn->full_name);
+ goto out;
+ }
+
+ msic->dcr_host = dcr_map(dn, msic->dcr_base, dcr_len);
+ if (!DCR_MAP_OK(msic->dcr_host)) {
+ printk(KERN_ERR "axon_msi: dcr_map failed for %s\n",
+ dn->full_name);
+ goto out_free_msic;
+ }
+
+ page = alloc_pages_node(of_node_to_nid(dn), GFP_KERNEL,
+ get_order(MSIC_FIFO_SIZE_BYTES));
+ if (!page) {
+ printk(KERN_ERR "axon_msi: couldn't allocate fifo for %s\n",
+ dn->full_name);
+ goto out_free_msic;
+ }
+
+ msic->fifo = page_address(page);
+
+ msic->irq_host = irq_alloc_host(IRQ_HOST_MAP_NOMAP, NR_IRQS,
+ &msic_host_ops, 0);
+ if (!msic->irq_host) {
+ printk(KERN_ERR "axon_msi: couldn't allocate irq_host for %s\n",
+ dn->full_name);
+ goto out_free_fifo;
+ }
+
+ msic->irq_host->host_data = msic;
+
+ virq = irq_of_parse_and_map(dn, 0);
+ if (virq == NO_IRQ) {
+ printk(KERN_ERR "axon_msi: irq parse and map failed for %s\n",
+ dn->full_name);
+ goto out_free_host;
+ }
+
+ msic->dn = of_node_get(dn);
+
+ set_irq_data(virq, msic);
+ set_irq_chained_handler(virq, axon_msi_cascade);
+ pr_debug("axon_msi: irq 0x%x setup for axon_msi\n", virq);
+
+ /* Enable the MSIC hardware */
+ msic_dcr_write(msic, MSIC_BASE_ADDR_HI_REG, (u64)msic->fifo >> 32);
+ msic_dcr_write(msic, MSIC_BASE_ADDR_LO_REG,
+ (u64)msic->fifo & 0xFFFFFFFF);
+ msic_dcr_write(msic, MSIC_CTRL_REG,
+ MSIC_CTRL_IRQ_ENABLE | MSIC_CTRL_ENABLE |
+ MSIC_CTRL_FIFO_SIZE);
+
+ list_add(&msic->list, &axon_msic_list);
+
+ printk(KERN_DEBUG "axon_msi: setup MSIC on %s\n", dn->full_name);
+
+ return 0;
+
+out_free_host:
+ kfree(msic->irq_host);
+out_free_fifo:
+ __free_pages(virt_to_page(msic->fifo), get_order(MSIC_FIFO_SIZE_BYTES));
+out_free_msic:
+ kfree(msic);
+out:
+
+ return -1;
+}
+
+static int axon_msi_init(void)
+{
+ struct device_node *dn;
+ int found = 0;
+
+ pr_debug("axon_msi: initialising ...\n");
+
+ for_each_compatible_node(dn, NULL, "ibm,axon-msic") {
+ if (axon_msi_setup_one(dn) == 0)
+ found++;
+ }
+
+ if (found) {
+ ppc_md.setup_msi_irqs = axon_msi_setup_msi_irqs;
+ ppc_md.teardown_msi_irqs = axon_msi_teardown_msi_irqs;
+ ppc_md.msi_check_device = axon_msi_check_device;
+
+ register_reboot_notifier(&axon_msi_reboot_notifier);
+
+ pr_debug("axon_msi: registered callbacks!\n");
+ }
+
+ return 0;
+}
+arch_initcall(axon_msi_init);
projects / kernel / kernel-generic.git / commitdiff