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![Dan Carpenter](/assets/img/avatar_default.png)
My static checker complains that the ">" should be ">=" or else we go beyond the end of the cb->irq_map[] array on the next line. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jason Cooper <jason@lakedaemon.net>
326 lines
7.2 KiB
C
326 lines
7.2 KiB
C
/*
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* drivers/irqchip/irq-crossbar.c
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*
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* Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
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* Author: Sricharan R <r.sricharan@ti.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/of_address.h>
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#include <linux/of_irq.h>
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#include <linux/slab.h>
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#include <linux/irqchip/arm-gic.h>
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#include <linux/irqchip/irq-crossbar.h>
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#define IRQ_FREE -1
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#define IRQ_RESERVED -2
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#define IRQ_SKIP -3
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#define GIC_IRQ_START 32
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/**
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* struct crossbar_device - crossbar device description
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* @int_max: maximum number of supported interrupts
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* @safe_map: safe default value to initialize the crossbar
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* @max_crossbar_sources: Maximum number of crossbar sources
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* @irq_map: array of interrupts to crossbar number mapping
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* @crossbar_base: crossbar base address
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* @register_offsets: offsets for each irq number
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* @write: register write function pointer
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*/
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struct crossbar_device {
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uint int_max;
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uint safe_map;
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uint max_crossbar_sources;
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uint *irq_map;
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void __iomem *crossbar_base;
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int *register_offsets;
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void (*write)(int, int);
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};
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static struct crossbar_device *cb;
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static inline void crossbar_writel(int irq_no, int cb_no)
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{
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writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
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}
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static inline void crossbar_writew(int irq_no, int cb_no)
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{
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writew(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
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}
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static inline void crossbar_writeb(int irq_no, int cb_no)
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{
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writeb(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
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}
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static inline int get_prev_map_irq(int cb_no)
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{
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int i;
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for (i = cb->int_max - 1; i >= 0; i--)
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if (cb->irq_map[i] == cb_no)
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return i;
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return -ENODEV;
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}
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static inline int allocate_free_irq(int cb_no)
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{
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int i;
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for (i = cb->int_max - 1; i >= 0; i--) {
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if (cb->irq_map[i] == IRQ_FREE) {
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cb->irq_map[i] = cb_no;
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return i;
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}
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}
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return -ENODEV;
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}
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static inline bool needs_crossbar_write(irq_hw_number_t hw)
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{
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int cb_no;
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if (hw > GIC_IRQ_START) {
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cb_no = cb->irq_map[hw - GIC_IRQ_START];
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if (cb_no != IRQ_RESERVED && cb_no != IRQ_SKIP)
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return true;
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}
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return false;
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}
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static int crossbar_domain_map(struct irq_domain *d, unsigned int irq,
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irq_hw_number_t hw)
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{
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if (needs_crossbar_write(hw))
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cb->write(hw - GIC_IRQ_START, cb->irq_map[hw - GIC_IRQ_START]);
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return 0;
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}
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/**
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* crossbar_domain_unmap - unmap a crossbar<->irq connection
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* @d: domain of irq to unmap
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* @irq: virq number
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*
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* We do not maintain a use count of total number of map/unmap
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* calls for a particular irq to find out if a irq can be really
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* unmapped. This is because unmap is called during irq_dispose_mapping(irq),
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* after which irq is anyways unusable. So an explicit map has to be called
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* after that.
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*/
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static void crossbar_domain_unmap(struct irq_domain *d, unsigned int irq)
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{
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irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq;
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if (needs_crossbar_write(hw)) {
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cb->irq_map[hw - GIC_IRQ_START] = IRQ_FREE;
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cb->write(hw - GIC_IRQ_START, cb->safe_map);
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}
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}
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static int crossbar_domain_xlate(struct irq_domain *d,
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struct device_node *controller,
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const u32 *intspec, unsigned int intsize,
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unsigned long *out_hwirq,
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unsigned int *out_type)
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{
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int ret;
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int req_num = intspec[1];
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int direct_map_num;
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if (req_num >= cb->max_crossbar_sources) {
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direct_map_num = req_num - cb->max_crossbar_sources;
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if (direct_map_num < cb->int_max) {
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ret = cb->irq_map[direct_map_num];
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if (ret == IRQ_RESERVED || ret == IRQ_SKIP) {
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/* We use the interrupt num as h/w irq num */
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ret = direct_map_num;
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goto found;
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}
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}
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pr_err("%s: requested crossbar number %d > max %d\n",
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__func__, req_num, cb->max_crossbar_sources);
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return -EINVAL;
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}
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ret = get_prev_map_irq(req_num);
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if (ret >= 0)
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goto found;
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ret = allocate_free_irq(req_num);
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if (ret < 0)
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return ret;
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found:
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*out_hwirq = ret + GIC_IRQ_START;
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return 0;
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}
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static const struct irq_domain_ops routable_irq_domain_ops = {
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.map = crossbar_domain_map,
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.unmap = crossbar_domain_unmap,
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.xlate = crossbar_domain_xlate
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};
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static int __init crossbar_of_init(struct device_node *node)
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{
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int i, size, max = 0, reserved = 0, entry;
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const __be32 *irqsr;
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int ret = -ENOMEM;
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cb = kzalloc(sizeof(*cb), GFP_KERNEL);
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if (!cb)
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return ret;
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cb->crossbar_base = of_iomap(node, 0);
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if (!cb->crossbar_base)
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goto err_cb;
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of_property_read_u32(node, "ti,max-crossbar-sources",
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&cb->max_crossbar_sources);
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if (!cb->max_crossbar_sources) {
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pr_err("missing 'ti,max-crossbar-sources' property\n");
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ret = -EINVAL;
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goto err_base;
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}
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of_property_read_u32(node, "ti,max-irqs", &max);
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if (!max) {
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pr_err("missing 'ti,max-irqs' property\n");
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ret = -EINVAL;
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goto err_base;
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}
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cb->irq_map = kcalloc(max, sizeof(int), GFP_KERNEL);
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if (!cb->irq_map)
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goto err_base;
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cb->int_max = max;
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for (i = 0; i < max; i++)
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cb->irq_map[i] = IRQ_FREE;
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/* Get and mark reserved irqs */
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irqsr = of_get_property(node, "ti,irqs-reserved", &size);
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if (irqsr) {
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size /= sizeof(__be32);
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for (i = 0; i < size; i++) {
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of_property_read_u32_index(node,
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"ti,irqs-reserved",
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i, &entry);
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if (entry >= max) {
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pr_err("Invalid reserved entry\n");
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ret = -EINVAL;
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goto err_irq_map;
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}
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cb->irq_map[entry] = IRQ_RESERVED;
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}
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}
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/* Skip irqs hardwired to bypass the crossbar */
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irqsr = of_get_property(node, "ti,irqs-skip", &size);
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if (irqsr) {
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size /= sizeof(__be32);
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for (i = 0; i < size; i++) {
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of_property_read_u32_index(node,
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"ti,irqs-skip",
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i, &entry);
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if (entry >= max) {
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pr_err("Invalid skip entry\n");
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ret = -EINVAL;
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goto err_irq_map;
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}
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cb->irq_map[entry] = IRQ_SKIP;
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}
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}
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cb->register_offsets = kcalloc(max, sizeof(int), GFP_KERNEL);
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if (!cb->register_offsets)
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goto err_irq_map;
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of_property_read_u32(node, "ti,reg-size", &size);
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switch (size) {
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case 1:
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cb->write = crossbar_writeb;
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break;
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case 2:
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cb->write = crossbar_writew;
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break;
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case 4:
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cb->write = crossbar_writel;
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break;
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default:
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pr_err("Invalid reg-size property\n");
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ret = -EINVAL;
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goto err_reg_offset;
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break;
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}
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/*
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* Register offsets are not linear because of the
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* reserved irqs. so find and store the offsets once.
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*/
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for (i = 0; i < max; i++) {
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if (cb->irq_map[i] == IRQ_RESERVED)
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continue;
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cb->register_offsets[i] = reserved;
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reserved += size;
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}
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of_property_read_u32(node, "ti,irqs-safe-map", &cb->safe_map);
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/* Initialize the crossbar with safe map to start with */
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for (i = 0; i < max; i++) {
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if (cb->irq_map[i] == IRQ_RESERVED ||
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cb->irq_map[i] == IRQ_SKIP)
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continue;
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cb->write(i, cb->safe_map);
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}
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register_routable_domain_ops(&routable_irq_domain_ops);
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return 0;
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err_reg_offset:
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kfree(cb->register_offsets);
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err_irq_map:
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kfree(cb->irq_map);
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err_base:
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iounmap(cb->crossbar_base);
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err_cb:
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kfree(cb);
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cb = NULL;
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return ret;
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}
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static const struct of_device_id crossbar_match[] __initconst = {
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{ .compatible = "ti,irq-crossbar" },
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{}
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};
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int __init irqcrossbar_init(void)
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{
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struct device_node *np;
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np = of_find_matching_node(NULL, crossbar_match);
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if (!np)
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return -ENODEV;
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crossbar_of_init(np);
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return 0;
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}
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