diff options
Diffstat (limited to 'arch/powerpc/platforms/wsp/ics.c')
-rw-r--r-- | arch/powerpc/platforms/wsp/ics.c | 712 |
1 files changed, 712 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/wsp/ics.c b/arch/powerpc/platforms/wsp/ics.c new file mode 100644 index 000000000000..e53bd9e7b125 --- /dev/null +++ b/arch/powerpc/platforms/wsp/ics.c @@ -0,0 +1,712 @@ +/* + * Copyright 2008-2011 IBM Corporation. + * + * 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. + */ + +#include <linux/cpu.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/irq.h> +#include <linux/kernel.h> +#include <linux/msi.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <linux/smp.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include <asm/io.h> +#include <asm/irq.h> +#include <asm/xics.h> + +#include "wsp.h" +#include "ics.h" + + +/* WSP ICS */ + +struct wsp_ics { + struct ics ics; + struct device_node *dn; + void __iomem *regs; + spinlock_t lock; + unsigned long *bitmap; + u32 chip_id; + u32 lsi_base; + u32 lsi_count; + u64 hwirq_start; + u64 count; +#ifdef CONFIG_SMP + int *hwirq_cpu_map; +#endif +}; + +#define to_wsp_ics(ics) container_of(ics, struct wsp_ics, ics) + +#define INT_SRC_LAYER_BUID_REG(base) ((base) + 0x00) +#define IODA_TBL_ADDR_REG(base) ((base) + 0x18) +#define IODA_TBL_DATA_REG(base) ((base) + 0x20) +#define XIVE_UPDATE_REG(base) ((base) + 0x28) +#define ICS_INT_CAPS_REG(base) ((base) + 0x30) + +#define TBL_AUTO_INCREMENT ((1UL << 63) | (1UL << 15)) +#define TBL_SELECT_XIST (1UL << 48) +#define TBL_SELECT_XIVT (1UL << 49) + +#define IODA_IRQ(irq) ((irq) & (0x7FFULL)) /* HRM 5.1.3.4 */ + +#define XIST_REQUIRED 0x8 +#define XIST_REJECTED 0x4 +#define XIST_PRESENTED 0x2 +#define XIST_PENDING 0x1 + +#define XIVE_SERVER_SHIFT 42 +#define XIVE_SERVER_MASK 0xFFFFULL +#define XIVE_PRIORITY_MASK 0xFFULL +#define XIVE_PRIORITY_SHIFT 32 +#define XIVE_WRITE_ENABLE (1ULL << 63) + +/* + * The docs refer to a 6 bit field called ChipID, which consists of a + * 3 bit NodeID and a 3 bit ChipID. On WSP the ChipID is always zero + * so we ignore it, and every where we use "chip id" in this code we + * mean the NodeID. + */ +#define WSP_ICS_CHIP_SHIFT 17 + + +static struct wsp_ics *ics_list; +static int num_ics; + +/* ICS Source controller accessors */ + +static u64 wsp_ics_get_xive(struct wsp_ics *ics, unsigned int irq) +{ + unsigned long flags; + u64 xive; + + spin_lock_irqsave(&ics->lock, flags); + out_be64(IODA_TBL_ADDR_REG(ics->regs), TBL_SELECT_XIVT | IODA_IRQ(irq)); + xive = in_be64(IODA_TBL_DATA_REG(ics->regs)); + spin_unlock_irqrestore(&ics->lock, flags); + + return xive; +} + +static void wsp_ics_set_xive(struct wsp_ics *ics, unsigned int irq, u64 xive) +{ + xive &= ~XIVE_ADDR_MASK; + xive |= (irq & XIVE_ADDR_MASK); + xive |= XIVE_WRITE_ENABLE; + + out_be64(XIVE_UPDATE_REG(ics->regs), xive); +} + +static u64 xive_set_server(u64 xive, unsigned int server) +{ + u64 mask = ~(XIVE_SERVER_MASK << XIVE_SERVER_SHIFT); + + xive &= mask; + xive |= (server & XIVE_SERVER_MASK) << XIVE_SERVER_SHIFT; + + return xive; +} + +static u64 xive_set_priority(u64 xive, unsigned int priority) +{ + u64 mask = ~(XIVE_PRIORITY_MASK << XIVE_PRIORITY_SHIFT); + + xive &= mask; + xive |= (priority & XIVE_PRIORITY_MASK) << XIVE_PRIORITY_SHIFT; + + return xive; +} + + +#ifdef CONFIG_SMP +/* Find logical CPUs within mask on a given chip and store result in ret */ +void cpus_on_chip(int chip_id, cpumask_t *mask, cpumask_t *ret) +{ + int cpu, chip; + struct device_node *cpu_dn, *dn; + const u32 *prop; + + cpumask_clear(ret); + for_each_cpu(cpu, mask) { + cpu_dn = of_get_cpu_node(cpu, NULL); + if (!cpu_dn) + continue; + + prop = of_get_property(cpu_dn, "at-node", NULL); + if (!prop) { + of_node_put(cpu_dn); + continue; + } + + dn = of_find_node_by_phandle(*prop); + of_node_put(cpu_dn); + + chip = wsp_get_chip_id(dn); + if (chip == chip_id) + cpumask_set_cpu(cpu, ret); + + of_node_put(dn); + } +} + +/* Store a suitable CPU to handle a hwirq in the ics->hwirq_cpu_map cache */ +static int cache_hwirq_map(struct wsp_ics *ics, unsigned int hwirq, + const cpumask_t *affinity) +{ + cpumask_var_t avail, newmask; + int ret = -ENOMEM, cpu, cpu_rover = 0, target; + int index = hwirq - ics->hwirq_start; + unsigned int nodeid; + + BUG_ON(index < 0 || index >= ics->count); + + if (!ics->hwirq_cpu_map) + return -ENOMEM; + + if (!distribute_irqs) { + ics->hwirq_cpu_map[hwirq - ics->hwirq_start] = xics_default_server; + return 0; + } + + /* Allocate needed CPU masks */ + if (!alloc_cpumask_var(&avail, GFP_KERNEL)) + goto ret; + if (!alloc_cpumask_var(&newmask, GFP_KERNEL)) + goto freeavail; + + /* Find PBus attached to the source of this IRQ */ + nodeid = (hwirq >> WSP_ICS_CHIP_SHIFT) & 0x3; /* 12:14 */ + + /* Find CPUs that could handle this IRQ */ + if (affinity) + cpumask_and(avail, cpu_online_mask, affinity); + else + cpumask_copy(avail, cpu_online_mask); + + /* Narrow selection down to logical CPUs on the same chip */ + cpus_on_chip(nodeid, avail, newmask); + + /* Ensure we haven't narrowed it down to 0 */ + if (unlikely(cpumask_empty(newmask))) { + if (unlikely(cpumask_empty(avail))) { + ret = -1; + goto out; + } + cpumask_copy(newmask, avail); + } + + /* Choose a CPU out of those we narrowed it down to in round robin */ + target = hwirq % cpumask_weight(newmask); + for_each_cpu(cpu, newmask) { + if (cpu_rover++ >= target) { + ics->hwirq_cpu_map[index] = get_hard_smp_processor_id(cpu); + ret = 0; + goto out; + } + } + + /* Shouldn't happen */ + WARN_ON(1); + +out: + free_cpumask_var(newmask); +freeavail: + free_cpumask_var(avail); +ret: + if (ret < 0) { + ics->hwirq_cpu_map[index] = cpumask_first(cpu_online_mask); + pr_warning("Error, falling hwirq 0x%x routing back to CPU %i\n", + hwirq, ics->hwirq_cpu_map[index]); + } + return ret; +} + +static void alloc_irq_map(struct wsp_ics *ics) +{ + int i; + + ics->hwirq_cpu_map = kmalloc(sizeof(int) * ics->count, GFP_KERNEL); + if (!ics->hwirq_cpu_map) { + pr_warning("Allocate hwirq_cpu_map failed, " + "IRQ balancing disabled\n"); + return; + } + + for (i=0; i < ics->count; i++) + ics->hwirq_cpu_map[i] = xics_default_server; +} + +static int get_irq_server(struct wsp_ics *ics, unsigned int hwirq) +{ + int index = hwirq - ics->hwirq_start; + + BUG_ON(index < 0 || index >= ics->count); + + if (!ics->hwirq_cpu_map) + return xics_default_server; + + return ics->hwirq_cpu_map[index]; +} +#else /* !CONFIG_SMP */ +static int cache_hwirq_map(struct wsp_ics *ics, unsigned int hwirq, + const cpumask_t *affinity) +{ + return 0; +} + +static int get_irq_server(struct wsp_ics *ics, unsigned int hwirq) +{ + return xics_default_server; +} + +static void alloc_irq_map(struct wsp_ics *ics) { } +#endif + +static void wsp_chip_unmask_irq(struct irq_data *d) +{ + unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); + struct wsp_ics *ics; + int server; + u64 xive; + + if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) + return; + + ics = d->chip_data; + if (WARN_ON(!ics)) + return; + + server = get_irq_server(ics, hw_irq); + + xive = wsp_ics_get_xive(ics, hw_irq); + xive = xive_set_server(xive, server); + xive = xive_set_priority(xive, DEFAULT_PRIORITY); + wsp_ics_set_xive(ics, hw_irq, xive); +} + +static unsigned int wsp_chip_startup(struct irq_data *d) +{ + /* unmask it */ + wsp_chip_unmask_irq(d); + return 0; +} + +static void wsp_mask_real_irq(unsigned int hw_irq, struct wsp_ics *ics) +{ + u64 xive; + + if (hw_irq == XICS_IPI) + return; + + if (WARN_ON(!ics)) + return; + xive = wsp_ics_get_xive(ics, hw_irq); + xive = xive_set_server(xive, xics_default_server); + xive = xive_set_priority(xive, LOWEST_PRIORITY); + wsp_ics_set_xive(ics, hw_irq, xive); +} + +static void wsp_chip_mask_irq(struct irq_data *d) +{ + unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); + struct wsp_ics *ics = d->chip_data; + + if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) + return; + + wsp_mask_real_irq(hw_irq, ics); +} + +static int wsp_chip_set_affinity(struct irq_data *d, + const struct cpumask *cpumask, bool force) +{ + unsigned int hw_irq = (unsigned int)irqd_to_hwirq(d); + struct wsp_ics *ics; + int ret; + u64 xive; + + if (hw_irq == XICS_IPI || hw_irq == XICS_IRQ_SPURIOUS) + return -1; + + ics = d->chip_data; + if (WARN_ON(!ics)) + return -1; + xive = wsp_ics_get_xive(ics, hw_irq); + + /* + * For the moment only implement delivery to all cpus or one cpu. + * Get current irq_server for the given irq + */ + ret = cache_hwirq_map(ics, d->irq, cpumask); + if (ret == -1) { + 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; + } else if (ret == -ENOMEM) { + pr_warning("%s: Out of memory\n", __func__); + return -1; + } + + xive = xive_set_server(xive, get_irq_server(ics, hw_irq)); + wsp_ics_set_xive(ics, hw_irq, xive); + + return 0; +} + +static struct irq_chip wsp_irq_chip = { + .name = "WSP ICS", + .irq_startup = wsp_chip_startup, + .irq_mask = wsp_chip_mask_irq, + .irq_unmask = wsp_chip_unmask_irq, + .irq_set_affinity = wsp_chip_set_affinity +}; + +static int wsp_ics_host_match(struct ics *ics, struct device_node *dn) +{ + /* All ICSs in the system implement a global irq number space, + * so match against them all. */ + return of_device_is_compatible(dn, "ibm,ppc-xics"); +} + +static int wsp_ics_match_hwirq(struct wsp_ics *wsp_ics, unsigned int hwirq) +{ + if (hwirq >= wsp_ics->hwirq_start && + hwirq < wsp_ics->hwirq_start + wsp_ics->count) + return 1; + + return 0; +} + +static int wsp_ics_map(struct ics *ics, unsigned int virq) +{ + struct wsp_ics *wsp_ics = to_wsp_ics(ics); + unsigned int hw_irq = virq_to_hw(virq); + unsigned long flags; + + if (!wsp_ics_match_hwirq(wsp_ics, hw_irq)) + return -ENOENT; + + irq_set_chip_and_handler(virq, &wsp_irq_chip, handle_fasteoi_irq); + + irq_set_chip_data(virq, wsp_ics); + + spin_lock_irqsave(&wsp_ics->lock, flags); + bitmap_allocate_region(wsp_ics->bitmap, hw_irq - wsp_ics->hwirq_start, 0); + spin_unlock_irqrestore(&wsp_ics->lock, flags); + + return 0; +} + +static void wsp_ics_mask_unknown(struct ics *ics, unsigned long hw_irq) +{ + struct wsp_ics *wsp_ics = to_wsp_ics(ics); + + if (!wsp_ics_match_hwirq(wsp_ics, hw_irq)) + return; + + pr_err("%s: IRQ %lu (real) is invalid, disabling it.\n", __func__, hw_irq); + wsp_mask_real_irq(hw_irq, wsp_ics); +} + +static long wsp_ics_get_server(struct ics *ics, unsigned long hw_irq) +{ + struct wsp_ics *wsp_ics = to_wsp_ics(ics); + + if (!wsp_ics_match_hwirq(wsp_ics, hw_irq)) + return -ENOENT; + + return get_irq_server(wsp_ics, hw_irq); +} + +/* HW Number allocation API */ + +static struct wsp_ics *wsp_ics_find_dn_ics(struct device_node *dn) +{ + struct device_node *iparent; + int i; + + iparent = of_irq_find_parent(dn); + if (!iparent) { + pr_err("wsp_ics: Failed to find interrupt parent!\n"); + return NULL; + } + + for(i = 0; i < num_ics; i++) { + if(ics_list[i].dn == iparent) + break; + } + + if (i >= num_ics) { + pr_err("wsp_ics: Unable to find parent bitmap!\n"); + return NULL; + } + + return &ics_list[i]; +} + +int wsp_ics_alloc_irq(struct device_node *dn, int num) +{ + struct wsp_ics *ics; + int order, offset; + + ics = wsp_ics_find_dn_ics(dn); + if (!ics) + return -ENODEV; + + /* Fast, but overly strict if num isn't a power of two */ + order = get_count_order(num); + + spin_lock_irq(&ics->lock); + offset = bitmap_find_free_region(ics->bitmap, ics->count, order); + spin_unlock_irq(&ics->lock); + + if (offset < 0) + return offset; + + return offset + ics->hwirq_start; +} + +void wsp_ics_free_irq(struct device_node *dn, unsigned int irq) +{ + struct wsp_ics *ics; + + ics = wsp_ics_find_dn_ics(dn); + if (WARN_ON(!ics)) + return; + + spin_lock_irq(&ics->lock); + bitmap_release_region(ics->bitmap, irq, 0); + spin_unlock_irq(&ics->lock); +} + +/* Initialisation */ + +static int __init wsp_ics_bitmap_setup(struct wsp_ics *ics, + struct device_node *dn) +{ + int len, i, j, size; + u32 start, count; + const u32 *p; + + size = BITS_TO_LONGS(ics->count) * sizeof(long); + ics->bitmap = kzalloc(size, GFP_KERNEL); + if (!ics->bitmap) { + pr_err("wsp_ics: ENOMEM allocating IRQ bitmap!\n"); + return -ENOMEM; + } + + spin_lock_init(&ics->lock); + + p = of_get_property(dn, "available-ranges", &len); + if (!p || !len) { + /* FIXME this should be a WARN() once mambo is updated */ + pr_err("wsp_ics: No available-ranges defined for %s\n", + dn->full_name); + return 0; + } + + if (len % (2 * sizeof(u32)) != 0) { + /* FIXME this should be a WARN() once mambo is updated */ + pr_err("wsp_ics: Invalid available-ranges for %s\n", + dn->full_name); + return 0; + } + + bitmap_fill(ics->bitmap, ics->count); + + for (i = 0; i < len / sizeof(u32); i += 2) { + start = of_read_number(p + i, 1); + count = of_read_number(p + i + 1, 1); + + pr_devel("%s: start: %d count: %d\n", __func__, start, count); + + if ((start + count) > (ics->hwirq_start + ics->count) || + start < ics->hwirq_start) { + pr_err("wsp_ics: Invalid range! -> %d to %d\n", + start, start + count); + break; + } + + for (j = 0; j < count; j++) + bitmap_release_region(ics->bitmap, + (start + j) - ics->hwirq_start, 0); + } + + /* Ensure LSIs are not available for allocation */ + bitmap_allocate_region(ics->bitmap, ics->lsi_base, + get_count_order(ics->lsi_count)); + + return 0; +} + +static int __init wsp_ics_setup(struct wsp_ics *ics, struct device_node *dn) +{ + u32 lsi_buid, msi_buid, msi_base, msi_count; + void __iomem *regs; + const u32 *p; + int rc, len, i; + u64 caps, buid; + + p = of_get_property(dn, "interrupt-ranges", &len); + if (!p || len < (2 * sizeof(u32))) { + pr_err("wsp_ics: No/bad interrupt-ranges found on %s\n", + dn->full_name); + return -ENOENT; + } + + if (len > (2 * sizeof(u32))) { + pr_err("wsp_ics: Multiple ics ranges not supported.\n"); + return -EINVAL; + } + + regs = of_iomap(dn, 0); + if (!regs) { + pr_err("wsp_ics: of_iomap(%s) failed\n", dn->full_name); + return -ENXIO; + } + + ics->hwirq_start = of_read_number(p, 1); + ics->count = of_read_number(p + 1, 1); + ics->regs = regs; + + ics->chip_id = wsp_get_chip_id(dn); + if (WARN_ON(ics->chip_id < 0)) + ics->chip_id = 0; + + /* Get some informations about the critter */ + caps = in_be64(ICS_INT_CAPS_REG(ics->regs)); + buid = in_be64(INT_SRC_LAYER_BUID_REG(ics->regs)); + ics->lsi_count = caps >> 56; + msi_count = (caps >> 44) & 0x7ff; + + /* Note: LSI BUID is 9 bits, but really only 3 are BUID and the + * rest is mixed in the interrupt number. We store the whole + * thing though + */ + lsi_buid = (buid >> 48) & 0x1ff; + ics->lsi_base = (ics->chip_id << WSP_ICS_CHIP_SHIFT) | lsi_buid << 5; + msi_buid = (buid >> 37) & 0x7; + msi_base = (ics->chip_id << WSP_ICS_CHIP_SHIFT) | msi_buid << 11; + + pr_info("wsp_ics: Found %s\n", dn->full_name); + pr_info("wsp_ics: irq range : 0x%06llx..0x%06llx\n", + ics->hwirq_start, ics->hwirq_start + ics->count - 1); + pr_info("wsp_ics: %4d LSIs : 0x%06x..0x%06x\n", + ics->lsi_count, ics->lsi_base, + ics->lsi_base + ics->lsi_count - 1); + pr_info("wsp_ics: %4d MSIs : 0x%06x..0x%06x\n", + msi_count, msi_base, + msi_base + msi_count - 1); + + /* Let's check the HW config is sane */ + if (ics->lsi_base < ics->hwirq_start || + (ics->lsi_base + ics->lsi_count) > (ics->hwirq_start + ics->count)) + pr_warning("wsp_ics: WARNING ! LSIs out of interrupt-ranges !\n"); + if (msi_base < ics->hwirq_start || + (msi_base + msi_count) > (ics->hwirq_start + ics->count)) + pr_warning("wsp_ics: WARNING ! MSIs out of interrupt-ranges !\n"); + + /* We don't check for overlap between LSI and MSI, which will happen + * if we use the same BUID, I'm not sure yet how legit that is. + */ + + rc = wsp_ics_bitmap_setup(ics, dn); + if (rc) { + iounmap(regs); + return rc; + } + + ics->dn = of_node_get(dn); + alloc_irq_map(ics); + + for(i = 0; i < ics->count; i++) + wsp_mask_real_irq(ics->hwirq_start + i, ics); + + ics->ics.map = wsp_ics_map; + ics->ics.mask_unknown = wsp_ics_mask_unknown; + ics->ics.get_server = wsp_ics_get_server; + ics->ics.host_match = wsp_ics_host_match; + + xics_register_ics(&ics->ics); + + return 0; +} + +static void __init wsp_ics_set_default_server(void) +{ + struct device_node *np; + u32 hwid; + + /* Find the server number for the boot cpu. */ + np = of_get_cpu_node(boot_cpuid, NULL); + BUG_ON(!np); + + hwid = get_hard_smp_processor_id(boot_cpuid); + + pr_info("wsp_ics: default server is %#x, CPU %s\n", hwid, np->full_name); + xics_default_server = hwid; + + of_node_put(np); +} + +static int __init wsp_ics_init(void) +{ + struct device_node *dn; + struct wsp_ics *ics; + int rc, found; + + wsp_ics_set_default_server(); + + found = 0; + for_each_compatible_node(dn, NULL, "ibm,ppc-xics") + found++; + + if (found == 0) { + pr_err("wsp_ics: No ICS's found!\n"); + return -ENODEV; + } + + ics_list = kmalloc(sizeof(*ics) * found, GFP_KERNEL); + if (!ics_list) { + pr_err("wsp_ics: No memory for structs.\n"); + return -ENOMEM; + } + + num_ics = 0; + ics = ics_list; + for_each_compatible_node(dn, NULL, "ibm,wsp-xics") { + rc = wsp_ics_setup(ics, dn); + if (rc == 0) { + ics++; + num_ics++; + } + } + + if (found != num_ics) { + pr_err("wsp_ics: Failed setting up %d ICS's\n", + found - num_ics); + return -1; + } + + return 0; +} + +void __init wsp_init_irq(void) +{ + wsp_ics_init(); + xics_init(); + + /* We need to patch our irq chip's EOI to point to the right ICP */ + wsp_irq_chip.irq_eoi = icp_ops->eoi; +} |