--- /dev/null
+#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)
+ pci_msi_unmask_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) {
+ pr_warning("%s: No online cpus in the mask %*pb for irq %d\n",
+ __func__, cpumask_pr_args(cpumask), 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");
+}
+
+__init 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;
+}
+
Code Review / kvmfornfv.git / blobdiff