2 files changed, 271 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pseries/Makefile b/arch/powerpc/platforms/pseries/Makefile
index 90235d598751..ae1fc92dc1c9 100644
--- a/arch/powerpc/platforms/pseries/Makefile
+++ b/arch/powerpc/platforms/pseries/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_SCANLOG)	+= scanlog.o
 obj-$(CONFIG_EEH)       += eeh.o eeh_cache.o eeh_driver.o eeh_event.o
 obj-$(CONFIG_KEXEC)     += kexec.o
 obj-$(CONFIG_PCI)       += pci.o pci_dlpar.o
+obj-$(CONFIG_PCI_MSI)   += msi.o
 
 obj-$(CONFIG_HOTPLUG_CPU)       += hotplug-cpu.o
 
diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c
new file mode 100644
index 000000000000..6063ea2f67ad
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/msi.c
@@ -0,0 +1,270 @@
+/*
+ * Copyright 2006 Jake Moilanen <moilanen@austin.ibm.com>, IBM Corp.
+ * Copyright 2006-2007 Michael Ellerman, IBM Corp.
+ *
+ * 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/device.h>
+#include <linux/irq.h>
+#include <linux/msi.h>
+
+#include <asm/rtas.h>
+#include <asm/hw_irq.h>
+#include <asm/ppc-pci.h>
+
+static int query_token, change_token;
+
+#define RTAS_QUERY_FN           0
+#define RTAS_CHANGE_FN          1
+#define RTAS_RESET_FN           2
+#define RTAS_CHANGE_MSI_FN      3
+#define RTAS_CHANGE_MSIX_FN     4
+
+static struct pci_dn *get_pdn(struct pci_dev *pdev)
+{
+        struct device_node *dn;
+        struct pci_dn *pdn;
+
+        dn = pci_device_to_OF_node(pdev);
+        if (!dn) {
+                dev_dbg(&pdev->dev, "rtas_msi: No OF device node\n");
+                return NULL;
+        }
+
+        pdn = PCI_DN(dn);
+        if (!pdn) {
+                dev_dbg(&pdev->dev, "rtas_msi: No PCI DN\n");
+                return NULL;
+        }
+
+        return pdn;
+}
+
+/* RTAS Helpers */
+
+static int rtas_change_msi(struct pci_dn *pdn, u32 func, u32 num_irqs)
+{
+        u32 addr, seq_num, rtas_ret[3];
+        unsigned long buid;
+        int rc;
+
+        addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
+        buid = pdn->phb->buid;
+
+        seq_num = 1;
+        do {
+                if (func == RTAS_CHANGE_MSI_FN || func == RTAS_CHANGE_MSIX_FN)
+                        rc = rtas_call(change_token, 6, 4, rtas_ret, addr,
+                                        BUID_HI(buid), BUID_LO(buid),
+                                        func, num_irqs, seq_num);
+                else
+                        rc = rtas_call(change_token, 6, 3, rtas_ret, addr,
+                                        BUID_HI(buid), BUID_LO(buid),
+                                        func, num_irqs, seq_num);
+
+                seq_num = rtas_ret[1];
+        } while (rtas_busy_delay(rc));
+
+        if (rc == 0) /* Success */
+                rc = rtas_ret[0];
+
+        pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d) = (%d)\n",
+                 func, num_irqs, rc);
+
+        return rc;
+}
+
+static void rtas_disable_msi(struct pci_dev *pdev)
+{
+        struct pci_dn *pdn;
+
+        pdn = get_pdn(pdev);
+        if (!pdn)
+                return;
+
+        if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0)
+                pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
+}
+
+static int rtas_query_irq_number(struct pci_dn *pdn, int offset)
+{
+        u32 addr, rtas_ret[2];
+        unsigned long buid;
+        int rc;
+
+        addr = rtas_config_addr(pdn->busno, pdn->devfn, 0);
+        buid = pdn->phb->buid;
+
+        do {
+                rc = rtas_call(query_token, 4, 3, rtas_ret, addr,
+                               BUID_HI(buid), BUID_LO(buid), offset);
+        } while (rtas_busy_delay(rc));
+
+        if (rc) {
+                pr_debug("rtas_msi: error (%d) querying source number\n", rc);
+                return rc;
+        }
+
+        return rtas_ret[0];
+}
+
+static void rtas_teardown_msi_irqs(struct pci_dev *pdev)
+{
+        struct msi_desc *entry;
+
+        list_for_each_entry(entry, &pdev->msi_list, list) {
+                if (entry->irq == NO_IRQ)
+                        continue;
+
+                set_irq_msi(entry->irq, NULL);
+                irq_dispose_mapping(entry->irq);
+        }
+
+        rtas_disable_msi(pdev);
+}
+
+static int check_req_msi(struct pci_dev *pdev, int nvec)
+{
+        struct device_node *dn;
+        struct pci_dn *pdn;
+        const u32 *req_msi;
+
+        pdn = get_pdn(pdev);
+        if (!pdn)
+                return -ENODEV;
+
+        dn = pdn->node;
+
+        req_msi = of_get_property(dn, "ibm,req#msi", NULL);
+        if (!req_msi) {
+                pr_debug("rtas_msi: No ibm,req#msi on %s\n", dn->full_name);
+                return -ENOENT;
+        }
+
+        if (*req_msi < nvec) {
+                pr_debug("rtas_msi: ibm,req#msi requests < %d MSIs\n", nvec);
+                return -ENOSPC;
+        }
+
+        return 0;
+}
+
+static int rtas_msi_check_device(struct pci_dev *pdev, int nvec, int type)
+{
+        if (type == PCI_CAP_ID_MSIX)
+                pr_debug("rtas_msi: MSI-X untested, trying anyway.\n");
+
+        return check_req_msi(pdev, nvec);
+}
+
+static int rtas_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type)
+{
+        struct pci_dn *pdn;
+        int hwirq, virq, i, rc;
+        struct msi_desc *entry;
+
+        pdn = get_pdn(pdev);
+        if (!pdn)
+                return -ENODEV;
+
+        /*
+         * Try the new more explicit firmware interface, if that fails fall
+         * back to the old interface. The old interface is known to never
+         * return MSI-Xs.
+         */
+        if (type == PCI_CAP_ID_MSI) {
+                rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
+
+                if (rc != nvec) {
+                        pr_debug("rtas_msi: trying the old firmware call.\n");
+                        rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
+                }
+        } else
+                rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
+
+        if (rc != nvec) {
+                pr_debug("rtas_msi: rtas_change_msi() failed\n");
+
+                /*
+                 * In case of an error it's not clear whether the device is
+                 * left with MSI enabled or not, so we explicitly disable.
+                 */
+                goto out_free;
+        }
+
+        i = 0;
+        list_for_each_entry(entry, &pdev->msi_list, list) {
+                hwirq = rtas_query_irq_number(pdn, i);
+                if (hwirq < 0) {
+                        rc = hwirq;
+                        pr_debug("rtas_msi: error (%d) getting hwirq\n", rc);
+                        goto out_free;
+                }
+
+                virq = irq_create_mapping(NULL, hwirq);
+
+                if (virq == NO_IRQ) {
+                        pr_debug("rtas_msi: Failed mapping hwirq %d\n", hwirq);
+                        rc = -ENOSPC;
+                        goto out_free;
+                }
+
+                dev_dbg(&pdev->dev, "rtas_msi: allocated virq %d\n", virq);
+                set_irq_msi(virq, entry);
+                unmask_msi_irq(virq);
+        }
+
+        return 0;
+
+ out_free:
+        rtas_teardown_msi_irqs(pdev);
+        return rc;
+}
+
+static void rtas_msi_pci_irq_fixup(struct pci_dev *pdev)
+{
+        /* No LSI -> leave MSIs (if any) configured */
+        if (pdev->irq == NO_IRQ) {
+                dev_dbg(&pdev->dev, "rtas_msi: no LSI, nothing to do.\n");
+                return;
+        }
+
+        /* No MSI -> MSIs can't have been assigned by fw, leave LSI */
+        if (check_req_msi(pdev, 1)) {
+                dev_dbg(&pdev->dev, "rtas_msi: no req#msi, nothing to do.\n");
+                return;
+        }
+
+        dev_dbg(&pdev->dev, "rtas_msi: disabling existing MSI.\n");
+        rtas_disable_msi(pdev);
+}
+
+static int rtas_msi_init(void)
+{
+        query_token  = rtas_token("ibm,query-interrupt-source-number");
+        change_token = rtas_token("ibm,change-msi");
+
+        if ((query_token == RTAS_UNKNOWN_SERVICE) ||
+                        (change_token == RTAS_UNKNOWN_SERVICE)) {
+                pr_debug("rtas_msi: no RTAS tokens, no MSI support.\n");
+                return -1;
+        }
+
+        pr_debug("rtas_msi: Registering RTAS MSI callbacks.\n");
+
+        WARN_ON(ppc_md.setup_msi_irqs);
+        ppc_md.setup_msi_irqs = rtas_setup_msi_irqs;
+        ppc_md.teardown_msi_irqs = rtas_teardown_msi_irqs;
+        ppc_md.msi_check_device = rtas_msi_check_device;
+
+        WARN_ON(ppc_md.pci_irq_fixup);
+        ppc_md.pci_irq_fixup = rtas_msi_pci_irq_fixup;
+
+        return 0;
+}
+arch_initcall(rtas_msi_init);