--- /dev/null
+/*
+ * ICS backend for OPAL managed interrupts.
+ *
+ * Copyright 2011 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; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#undef DEBUG
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/cpu.h>
+#include <linux/of.h>
+#include <linux/spinlock.h>
+#include <linux/msi.h>
+
+#include <asm/prom.h>
+#include <asm/smp.h>
+#include <asm/machdep.h>
+#include <asm/irq.h>
+#include <asm/errno.h>
+#include <asm/xics.h>
+#include <asm/opal.h>
+#include <asm/firmware.h>
+
+static int ics_opal_mangle_server(int server)
+{
+ /* No link for now */
+ return server << 2;
+}
+
+static int ics_opal_unmangle_server(int server)
+{
+ /* No link for now */
+ return server >> 2;
+}
+
+static void ics_opal_unmask_irq(struct irq_data *d)
+{
+ unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+ int64_t rc;
+ int server;
+
+ pr_devel("ics-hal: unmask virq %d [hw 0x%x]\n", d->irq, hw_irq);
+
+ if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
+ return;
+
+ server = xics_get_irq_server(d->irq, d->affinity, 0);
+ server = ics_opal_mangle_server(server);
+
+ rc = opal_set_xive(hw_irq, server, DEFAULT_PRIORITY);
+ if (rc != OPAL_SUCCESS)
+ pr_err("%s: opal_set_xive(irq=%d [hw 0x%x] server=%x)"
+ " error %lld\n",
+ __func__, d->irq, hw_irq, server, rc);
+}
+
+static unsigned int ics_opal_startup(struct irq_data *d)
+{
+#ifdef CONFIG_PCI_MSI
+ /*
+ * The generic MSI code returns with the interrupt disabled on the
+ * card, using the MSI mask bits. Firmware doesn't appear to unmask
+ * at that level, so we do it here by hand.
+ */
+ if (d->msi_desc)
+ unmask_msi_irq(d);
+#endif
+
+ /* unmask it */
+ ics_opal_unmask_irq(d);
+ return 0;
+}
+
+static void ics_opal_mask_real_irq(unsigned int hw_irq)
+{
+ int server = ics_opal_mangle_server(xics_default_server);
+ int64_t rc;
+
+ if (hw_irq == XICS_IPI)
+ return;
+
+ /* Have to set XIVE to 0xff to be able to remove a slot */
+ rc = opal_set_xive(hw_irq, server, 0xff);
+ if (rc != OPAL_SUCCESS)
+ pr_err("%s: opal_set_xive(0xff) irq=%u returned %lld\n",
+ __func__, hw_irq, rc);
+}
+
+static void ics_opal_mask_irq(struct irq_data *d)
+{
+ unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+
+ pr_devel("ics-hal: mask virq %d [hw 0x%x]\n", d->irq, hw_irq);
+
+ if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
+ return;
+ ics_opal_mask_real_irq(hw_irq);
+}
+
+static int ics_opal_set_affinity(struct irq_data *d,
+ const struct cpumask *cpumask,
+ bool force)
+{
+ unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+ int16_t server;
+ int8_t priority;
+ int64_t rc;
+ int wanted_server;
+
+ if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
+ return -1;
+
+ rc = opal_get_xive(hw_irq, &server, &priority);
+ if (rc != OPAL_SUCCESS) {
+ pr_err("%s: opal_set_xive(irq=%d [hw 0x%x] server=%x)"
+ " error %lld\n",
+ __func__, d->irq, hw_irq, server, rc);
+ return -1;
+ }
+
+ wanted_server = xics_get_irq_server(d->irq, cpumask, 1);
+ if (wanted_server < 0) {
+ char cpulist[128];
+ cpumask_scnprintf(cpulist, sizeof(cpulist), cpumask);
+ pr_warning("%s: No online cpus in the mask %s for irq %d\n",
+ __func__, cpulist, d->irq);
+ return -1;
+ }
+ server = ics_opal_mangle_server(wanted_server);
+
+ pr_devel("ics-hal: set-affinity irq %d [hw 0x%x] server: 0x%x/0x%x\n",
+ d->irq, hw_irq, wanted_server, server);
+
+ rc = opal_set_xive(hw_irq, server, priority);
+ if (rc != OPAL_SUCCESS) {
+ pr_err("%s: opal_set_xive(irq=%d [hw 0x%x] server=%x)"
+ " error %lld\n",
+ __func__, d->irq, hw_irq, server, rc);
+ return -1;
+ }
+ return 0;
+}
+
+static struct irq_chip ics_opal_irq_chip = {
+ .name = "OPAL ICS",
+ .irq_startup = ics_opal_startup,
+ .irq_mask = ics_opal_mask_irq,
+ .irq_unmask = ics_opal_unmask_irq,
+ .irq_eoi = NULL, /* Patched at init time */
+ .irq_set_affinity = ics_opal_set_affinity
+};
+
+static int ics_opal_map(struct ics *ics, unsigned int virq);
+static void ics_opal_mask_unknown(struct ics *ics, unsigned long vec);
+static long ics_opal_get_server(struct ics *ics, unsigned long vec);
+
+static int ics_opal_host_match(struct ics *ics, struct device_node *node)
+{
+ return 1;
+}
+
+/* Only one global & state struct ics */
+static struct ics ics_hal = {
+ .map = ics_opal_map,
+ .mask_unknown = ics_opal_mask_unknown,
+ .get_server = ics_opal_get_server,
+ .host_match = ics_opal_host_match,
+};
+
+static int ics_opal_map(struct ics *ics, unsigned int virq)
+{
+ unsigned int hw_irq = (unsigned int)virq_to_hw(virq);
+ int64_t rc;
+ int16_t server;
+ int8_t priority;
+
+ if (WARN_ON(hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS))
+ return -EINVAL;
+
+ /* Check if HAL knows about this interrupt */
+ rc = opal_get_xive(hw_irq, &server, &priority);
+ if (rc != OPAL_SUCCESS)
+ return -ENXIO;
+
+ irq_set_chip_and_handler(virq, &ics_opal_irq_chip, handle_fasteoi_irq);
+ irq_set_chip_data(virq, &ics_hal);
+
+ return 0;
+}
+
+static void ics_opal_mask_unknown(struct ics *ics, unsigned long vec)
+{
+ int64_t rc;
+ int16_t server;
+ int8_t priority;
+
+ /* Check if HAL knows about this interrupt */
+ rc = opal_get_xive(vec, &server, &priority);
+ if (rc != OPAL_SUCCESS)
+ return;
+
+ ics_opal_mask_real_irq(vec);
+}
+
+static long ics_opal_get_server(struct ics *ics, unsigned long vec)
+{
+ int64_t rc;
+ int16_t server;
+ int8_t priority;
+
+ /* Check if HAL knows about this interrupt */
+ rc = opal_get_xive(vec, &server, &priority);
+ if (rc != OPAL_SUCCESS)
+ return -1;
+ return ics_opal_unmangle_server(server);
+}
+
+int __init ics_opal_init(void)
+{
+ if (!firmware_has_feature(FW_FEATURE_OPAL))
+ return -ENODEV;
+
+ /* We need to patch our irq chip's EOI to point to the
+ * right ICP
+ */
+ ics_opal_irq_chip.irq_eoi = icp_ops->eoi;
+
+ /* Register ourselves */
+ xics_register_ics(&ics_hal);
+
+ pr_info("ICS OPAL backend registered\n");
+
+ return 0;
+}
projects / platform / upstream / kernel-adaptation-pc.git / commitdiff