diff options
Diffstat (limited to 'arch/powerpc/sysdev/xics/ics-rtas.c')
| -rw-r--r-- | arch/powerpc/sysdev/xics/ics-rtas.c | 240 |
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 000000000..6aabc7468 --- /dev/null +++ b/arch/powerpc/sysdev/xics/ics-rtas.c @@ -0,0 +1,240 @@ +// 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/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, irq_data_get_affinity_mask(d), 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 (irq_data_get_msi_desc(d)) + 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_warn("%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, + .irq_set_type = xics_set_irq_type, + .irq_retrigger = xics_retrigger, +}; + +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; +} + |