1 files changed, 240 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/xics/ics-rtas.c b/arch/powerpc/sysdev/xics/ics-rtas.c
new file mode 100644
index 000000000000..c782f85cf7e4
--- /dev/null
+++ b/arch/powerpc/sysdev/xics/ics-rtas.c
@@ -0,0 +1,240 @@
+#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/rtas.h>
+
+/* RTAS service tokens */
+static int ibm_get_xive;
+static int ibm_set_xive;
+static int ibm_int_on;
+static int ibm_int_off;
+
+static int ics_rtas_map(struct ics *ics, unsigned int virq);
+static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec);
+static long ics_rtas_get_server(struct ics *ics, unsigned long vec);
+static int ics_rtas_host_match(struct ics *ics, struct device_node *node);
+
+/* Only one global & state struct ics */
+static struct ics ics_rtas = {
+        .map            = ics_rtas_map,
+        .mask_unknown   = ics_rtas_mask_unknown,
+        .get_server     = ics_rtas_get_server,
+        .host_match     = ics_rtas_host_match,
+};
+
+static void ics_rtas_unmask_irq(struct irq_data *d)
+{
+        unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+        int call_status;
+        int server;
+
+        pr_devel("xics: 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);
+
+        call_status = rtas_call(ibm_set_xive, 3, 1, NULL, hw_irq, server,
+                                DEFAULT_PRIORITY);
+        if (call_status != 0) {
+                printk(KERN_ERR
+                        "%s: ibm_set_xive irq %u server %x returned %d\n",
+                        __func__, hw_irq, server, call_status);
+                return;
+        }
+
+        /* Now unmask the interrupt (often a no-op) */
+        call_status = rtas_call(ibm_int_on, 1, 1, NULL, hw_irq);
+        if (call_status != 0) {
+                printk(KERN_ERR "%s: ibm_int_on irq=%u returned %d\n",
+                        __func__, hw_irq, call_status);
+                return;
+        }
+}
+
+static unsigned int ics_rtas_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_rtas_unmask_irq(d);
+        return 0;
+}
+
+static void ics_rtas_mask_real_irq(unsigned int hw_irq)
+{
+        int call_status;
+
+        if (hw_irq == XICS_IPI)
+                return;
+
+        call_status = rtas_call(ibm_int_off, 1, 1, NULL, hw_irq);
+        if (call_status != 0) {
+                printk(KERN_ERR "%s: ibm_int_off irq=%u returned %d\n",
+                        __func__, hw_irq, call_status);
+                return;
+        }
+
+        /* Have to set XIVE to 0xff to be able to remove a slot */
+        call_status = rtas_call(ibm_set_xive, 3, 1, NULL, hw_irq,
+                                xics_default_server, 0xff);
+        if (call_status != 0) {
+                printk(KERN_ERR "%s: ibm_set_xive(0xff) irq=%u returned %d\n",
+                        __func__, hw_irq, call_status);
+                return;
+        }
+}
+
+static void ics_rtas_mask_irq(struct irq_data *d)
+{
+        unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+
+        pr_devel("xics: mask virq %d [hw 0x%x]\n", d->irq, hw_irq);
+
+        if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
+                return;
+        ics_rtas_mask_real_irq(hw_irq);
+}
+
+static int ics_rtas_set_affinity(struct irq_data *d,
+                                 const struct cpumask *cpumask,
+                                 bool force)
+{
+        unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d);
+        int status;
+        int xics_status[2];
+        int irq_server;
+
+        if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS)
+                return -1;
+
+        status = rtas_call(ibm_get_xive, 1, 3, xics_status, hw_irq);
+
+        if (status) {
+                printk(KERN_ERR "%s: ibm,get-xive irq=%u returns %d\n",
+                        __func__, hw_irq, status);
+                return -1;
+        }
+
+        irq_server = xics_get_irq_server(d->irq, cpumask, 1);
+        if (irq_server == -1) {
+                char cpulist[128];
+                cpumask_scnprintf(cpulist, sizeof(cpulist), cpumask);
+                printk(KERN_WARNING
+                        "%s: No online cpus in the mask %s for irq %d\n",
+                        __func__, cpulist, d->irq);
+                return -1;
+        }
+
+        status = rtas_call(ibm_set_xive, 3, 1, NULL,
+                           hw_irq, irq_server, xics_status[1]);
+
+        if (status) {
+                printk(KERN_ERR "%s: ibm,set-xive irq=%u returns %d\n",
+                        __func__, hw_irq, status);
+                return -1;
+        }
+
+        return IRQ_SET_MASK_OK;
+}
+
+static struct irq_chip ics_rtas_irq_chip = {
+        .name = "XICS",
+        .irq_startup = ics_rtas_startup,
+        .irq_mask = ics_rtas_mask_irq,
+        .irq_unmask = ics_rtas_unmask_irq,
+        .irq_eoi = NULL, /* Patched at init time */
+        .irq_set_affinity = ics_rtas_set_affinity
+};
+
+static int ics_rtas_map(struct ics *ics, unsigned int virq)
+{
+        unsigned int hw_irq = (unsigned int)virq_to_hw(virq);
+        int status[2];
+        int rc;
+
+        if (WARN_ON(hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS))
+                return -EINVAL;
+
+        /* Check if RTAS knows about this interrupt */
+        rc = rtas_call(ibm_get_xive, 1, 3, status, hw_irq);
+        if (rc)
+                return -ENXIO;
+
+        irq_set_chip_and_handler(virq, &ics_rtas_irq_chip, handle_fasteoi_irq);
+        irq_set_chip_data(virq, &ics_rtas);
+
+        return 0;
+}
+
+static void ics_rtas_mask_unknown(struct ics *ics, unsigned long vec)
+{
+        ics_rtas_mask_real_irq(vec);
+}
+
+static long ics_rtas_get_server(struct ics *ics, unsigned long vec)
+{
+        int rc, status[2];
+
+        rc = rtas_call(ibm_get_xive, 1, 3, status, vec);
+        if (rc)
+                return -1;
+        return status[0];
+}
+
+static int ics_rtas_host_match(struct ics *ics, struct device_node *node)
+{
+        /* IBM machines have interrupt parents of various funky types for things
+         * like vdevices, events, etc... The trick we use here is to match
+         * everything here except the legacy 8259 which is compatible "chrp,iic"
+         */
+        return !of_device_is_compatible(node, "chrp,iic");
+}
+
+int ics_rtas_init(void)
+{
+        ibm_get_xive = rtas_token("ibm,get-xive");
+        ibm_set_xive = rtas_token("ibm,set-xive");
+        ibm_int_on  = rtas_token("ibm,int-on");
+        ibm_int_off = rtas_token("ibm,int-off");
+
+        /* We enable the RTAS "ICS" if RTAS is present with the
+         * appropriate tokens
+         */
+        if (ibm_get_xive == RTAS_UNKNOWN_SERVICE ||
+            ibm_set_xive == RTAS_UNKNOWN_SERVICE)
+                return -ENODEV;
+
+        /* We need to patch our irq chip's EOI to point to the
+         * right ICP
+         */
+        ics_rtas_irq_chip.irq_eoi = icp_ops->eoi;
+
+        /* Register ourselves */
+        xics_register_ics(&ics_rtas);
+
+        return 0;
+}
+