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 00000000000..e53bd9e7b12 --- /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; +}  |