| // SPDX-License-Identifier: GPL-2.0 |
| #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/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 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, irq_data_get_affinity_mask(d), 0); |
| |
| call_status = rtas_call_reentrant(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_reentrant(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) |
| { |
| /* 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_reentrant(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_reentrant(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_reentrant(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_warn("%s: No online cpus in the mask %*pb for irq %d\n", |
| __func__, cpumask_pr_args(cpumask), d->irq); |
| return -1; |
| } |
| |
| pr_debug("%s: irq %d [hw 0x%x] server: 0x%x\n", __func__, d->irq, |
| hw_irq, irq_server); |
| |
| status = rtas_call_reentrant(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, |
| .irq_set_type = xics_set_irq_type, |
| .irq_retrigger = xics_retrigger, |
| }; |
| |
| static int ics_rtas_check(struct ics *ics, unsigned int hw_irq) |
| { |
| 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_reentrant(ibm_get_xive, 1, 3, status, hw_irq); |
| if (rc) |
| return -ENXIO; |
| |
| 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_reentrant(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"); |
| } |
| |
| /* Only one global & state struct ics */ |
| static struct ics ics_rtas = { |
| .check = ics_rtas_check, |
| .mask_unknown = ics_rtas_mask_unknown, |
| .get_server = ics_rtas_get_server, |
| .host_match = ics_rtas_host_match, |
| .chip = &ics_rtas_irq_chip, |
| }; |
| |
| __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; |
| } |
| |